First data on lipids and microorganisms of deepwater endemic sponge Baikalospongia intermedia and sediments from hydrothermal discharge area of the Frolikha Bay (North Baikal, Siberia)
8 ноя 2019
В журнале Journal of Great Lakes Research (IF-1.933) опубликована статья Раднаевой Л.Д., Базарсадуевой С.В., Тараскина В.В., Тулохонова А.К. «First data on lipids and microorganisms of deepwater endemic sponge Baikalospongia intermedia and sediments from hydrothermal discharge area of the Frolikha Bay (North Baikal, Siberia)».
Journal of Great Lakes Research. Volume 46, Issue 1, February 2020, Pages 67-74.
In this report, we study lipid components (fatty acids with various degrees of unsaturation, aldehydes and sterols) of deep-water sponges Baikalospongia intermedia and sediments sampled using deep-water manned submersibles “Mir” at a hydrothermal vent of Frolikha Bay at depths of 400–450 m. It was found that unsaturated fatty acids predominate in the FA-composition of the sponges: very long chain demospongic acid 26:3, as well as monounsaturated 24:1 and isomers of acids 16:1 and 18:1. Among the saturated fatty acids in addition to the stearic 18:0, palmitic 16:0 and heptadecanoic 17:0 acids, significant amounts of acids of microbial origin (iso-palmitic i16:0, isostearic i18:0, oxy-stearic 10 h18) were detected. Using the method of mass spectrometry of microbial markers, we conclude, that the main microbial components of sponges B. intermedia and sediments from Frolikha Bay are methanotrophic microorganisms.
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First data on lipids and microorganisms of deepwater endemic sponge Baikalospongia intermedia and sediments from hydrothermal discharge area of the Frolikha Bay (North Baikal, Siberia)
Раднаевой Л.Д., Базарсадуевой С.В., Тараскина В.В., Тулохонова А.К.
Ведущие статьи (Q1-Q2) БИП СО РАН за
Zhigzhitzhapova, S.V. Chemical composition of
volatile organic compounds of Artemisia
vulgaris L. (Asteraceae) from
the Qinghai-Tibet Plateau / S.V. Zhigzhitzhapova, L.D. Radnaeva, Q.B. Gao et al. // Industrial Crops and Products. –
2016. – Vol. 83. – P. 462-469. https://doi.org/10.1016/j.indcrop.2015.12.083 (IF JСR=5,645 (3,181); Q1). https://www.webofscience.com/wos/woscc/full-record/WOS:000370894000059
Plants growing in different climate retain the
general direction of the biosynthesis of the volatile organic compound (VOC).
The aim of this study was to investigate the VOC composition in Artemisia
vulgaris L. growing on the
Qinghai–Tibet Plateau. The VOCs were isolated by hydrodistillation or
by headspace extraction, and their composition was analyzed by gas
chromatography–mass spectrometry (GC–MS). There were 96 VOCs identified in
the samples, accounting for 91–97% of the total. Monoterpenes (80.33%) were
the main components of VOCs released by headspace extraction. The major components
oil obtained by hydrodistillation were monoterpenes
(44.49%) and sesquiterpenes (29.98%). The monoterpenes 1,8-cineole, camphor, and α- and β- thujones were the main VOCs detected after both
hydrodistillation and headspace extraction. Sesquiterpenes (cis-davanone, germacrene D) also accounted for a significant
proportion of compounds in the essential oil. A principal component analysis
(PCA) based on the types of components of essential oils of A.
vulgaris collected from different countries showed that the moisture
conditions at the collection site was the main factor explaining variations
in VOC composition, and were located between “European” and “Siberian”
chemotype, which indicated that the essential oil profile does not fully
reflect zonal climatic features.
Stelmakh S.A., Ukshe A.E., Mognonov D.M., Novikova K.S., Grigor'eva M.N., Kayumov R.R., Bal'zhinov S.A., Dobrovolsky Y.A. Proton conductivity of new type medium-temperature
proton exchange membranes // Ionics. – 2016. – Vol.22 (№10). – pp.1873–1880. Doi: 10.1007/s11581-016-1722-1 (IF
This work reports on the analysis of
physicochemical properties including proton conductivity of a new class of
composite proton exchange membranes based on N-phenyl-substituted
polyhexamethylene guanidine (PHMG) and poly-m-phenylene isophthalamide (phenylone)
doped with phosphoric acid (PHMGP-PA) at different temperatures and
environmental humidity. The presence of a strong ionic bond between
protonated PHMGP and phosphoric acid anions allowed one to expect that the
composite material is capable to retain phosphoric acid even in conditions of
high humidity and temperature.
Reshak, A. H. Electronic
structure of monoclinic - Exploration of the Electronic Structure of
Monoclinic α-Eu2(MoO4)3: DFT-Based Study and X-ray Photoelectron Spectroscopy
/ A.H. Reshak, Z.A. Alahmed, J. Bila, V.V. Atuchin, B.G. Bazarov, O.D.
Chimitova, M.S. Molokeev, I.P. Prosvirin, A.P. Yelisseyev // J. Phys. Chem.
C. – 2016, V. 120, № 19. – Р. 10559−10568. DOI: 10.1021/acs.jpcc.6b01489 (IF
JCR 4.536 (2016); Q1).
The powder α-Eu2(MoO4)3 sample
was prepared by the solid-state reaction method. The phase purity of the
final powder product was verified by X-ray diffraction analysis. The
constituent element core levels and valence band are measured by X-ray
photoelectron spectroscopy as a function of Ar+ ion (2.5 keV,
bombardment time. The formation of Mo5+ and Mo4+ states
at high bombardment times was detected. The Eu–O and Mo–O bonding was
considered in comparison with other Eu3+- and Mo6+-containing
oxides using binding energy difference parameters. The transparency range
obtained for the pure α-Eu2(MoO4)3 tablet
is λ = 0.41–0.97 μm, as estimated at the
transmission level of 5%. The short-wavelength cut edge in α-Eu2(MoO4)3 is
governed by the direct allowed optical transitions within the band gap
of Eg = 3.74 eV (300 K). The band structure of α-Eu2(MoO4)3 was
calculated by ab initio methods and strongly different
results were obtained for the spin up/down configurations. The Eu-4f states are located around
2.2 eV and −4.0 eV for spin up (↑) and the structures situated at around 6.5
and 5.5 eV for spin down (↓) configuration. The calculated spin magnetic
moments are in excellent relation to the Slater-Pauling rule and within the
Eu sphere the magnetic moment of 4f
electrons is ∼5.99 μB.
Kotova, I.Yu. New series of triple molybdates AgA3R(MoO4)5 (A = Mg, R =
Cr, Fe; A = Mn, R = Al, Cr, Fe, Sc, In) with framework structures and mobile
silver ion sublattices / I.Yu. Kotova, S.F. Solodovnikov, Z.A. Solodovnikova,
D.A. Belov, S.Yu. Stefanovich, A.A. Savina, E.G. Khaikina // J. Solid State
Chem. – 2016. – V. 238. – P. 121–128. http://dx.doi.org/10.1016/j.jssc.2016.03.003 (IF JCR 2.299;
Triple molybdates AgA3R(MoO4)5
(A=Mg, R=Cr, Fe; A=Mn, R=Al, Cr, Fe, Sc, In) of the NaMg3In(MoO4)5 type were synthesized and single crystals
of AgMg3R(MoO4)5 (R=Cr, Fe) were grown. In their
structures, the MoO4 tetrahedra, pairs and trimers of edge-shared (Mg, R)O6
octahedra are connected by common vertices to form a 3D framework. Large
framework cavities involve Ag+ cations disordered on three nearby positions
with CN=3+1 or 4+1. Alternating (Mg, R)O6 octahedra and MoO4
tetrahedra in the framework form quadrangular windows penetrable for Ag+ at
elevated temperatures. Above 653–673 K, the newly obtained molybdates
demonstrate abrupt reduction of the activation energy to 0.4–0.6 eV. At 773
K, AgMg3Al(MoO4)5 shows electric conductivity 2.5·10−2 S/cm and Ea=0.39 eV
compatible with characteristics of the best ionic conductors of the NASICON
Zolotova, E.S. Phase relations in the Na2MoO4–Cs2MoO4 and
Na2MoO4–Cs2MoO4–ZnMoO4 systems, crystal structures of Cs3Na(MoO4)2 and
Cs3NaZn2(MoO4)4 / E.S. Zolotova, V.N.
Yudin, S.F. Solodovnikov, E.G. Khaikina, O.M. Basovich, I.V. Korolkov, I.Yu.
Filatova // J. Solid State Chem. – 2016. – V. 233. – P. 23–29.
https://doi.org/10.1016/j.jssc.2015.10.008 (IF JCR- 2.299; Q2).
The phase diagram of the Na2MoO4-Cs2MoO4 system
was reinvestigated and a new intermediate compound, Cs3Na(MoO4)(2), melting
incongruently at 510 degrees C was found. Its crystal structure (a=6.3461(2),
c=8.2209(3) angstrom, sp. gr. P (3) over bar m1, Z=1, R=0.0131) belongs to
the glaserite type. Taking into account these data, the subsolidus phase
relations of the system Na2MoO4-Cs2MoO4-ZnMoO4 was studied at 420 degrees C.
The filling vacancies in the tetrahedral Zn position of the Cs6Zn5(MoO4)(8)
structure (sp. gr. 1 (4) over bar 3d, Z=2) following the scheme Zn2+ +square
-> 2Na(+) was established to result in the continuous solid solution
Cs6Zn5-x square Na-1-x(2x)(MoO4)(8) (0 <= x <= 1). With increasing the
x value, the cubic lattice parameter of the solid solution increases linearly
while its melting point decreases that testifies to destabilization of the
Cs6Zn5(MoO4)(8) structure by a progressive Na+ insertion. In the structure of
Cs3NaZn2(MoO4)(4) (a=12.3134(1) angstrom, R=0.0121), Mo04 and (Zn2/3Na1/3)O-4
tetrahedra share corners to form an open 3D framework. The cesium ions are
disordered around the centers of the cuboctahedral cavities of the framework
to form "clusters" of the central Cs(1) and four disordered Cs(2)
Tsyrenova, G.D. New ferroelastic K2Sr(MoO4)2: Synthesis, phase
transitions, crystal and domain structures, ionic conductivity / G.D.
Tsyrenova, E.T. Pavlova, S.F. Solodovnikov, N.N. Popova, T.Yu. Kardash, S.Yu.
Stefanovich, I.А. Gudkova, Z.A. Solodovnikova, B.I. Lazoryak // // J. Solid
State Chem. – 2016. – V. 237. – P. 64–71. https://doi.org/10.1016/j.jssc.2016.01.011 (IF
JCR- 2.299; Q2).
K2Sr(MoO4)(2) crystals were synthesized and their
properties examined. The distortive polymorphic transformations at 421 K
(alpha (LT) -> beta(MT)) and 744 K (beta(MT)->gamma (HT)) of
K2Sr(MoO4)(2) were studied. It has been shown that the transitions go in sequence
from the high-temperature palmierite K2Pb(SO4)(2)-type gamma-phase (R (3)
over barm) to an intermediate beta-phase with a probable incommensurate
structure and then to a low-temperature alpha-phase. Domain structures
peculiarities in ferroelastic alpha-K2Sr(MoO4)(2) have been investigated. The
electrical conductivity of K2Sr(MoO4)(2) rises tenfold in the vicinity of the
phase transition at 744 K that may be associated with a change conductivity
path from quasi-one-dimensional to two-dimensional. The crystal structure of
the alpha-phase (sp. gr. C2/c, a=14.318(3) angstrom, b=5.9337(12) angstrom,
c=10.422(2) angstrom, beta=105.83(3)degrees, Z=4, R=0.0219) is similar to
that of alpha-Pb-3(PO4)(2). Sr atoms are mainly located at site with the
coordination number CN=8 (a tetragonal antiprism with bond lengths of
2.578(2)-2.789(2) angstrom) and K atoms are located at site with CN=9+1.
Stelmakh S.A., Ukshe A.E., Mognonov D.M., Novikova K.S., Grigor'eva M.N., Kayumov R.R., Bal'zhinov S.A., Dobrovolsky Y.A. Proton conductivity of new type medium-temperature
proton exchange membranes. Ionics V22, №10, 1873–1880 – 2016. Doi: 10.1007/s11581-016-1722-1 (IF=1.754,
Among polymer fuel cells (FC), there is a class of
devices where phosphoric acid is used as electrolyte. The retention of acid
in a polymer matrix is provided by binding a part of its molecules with basic
groups of the polymer. Operating temperature for such medium-temperature FC
can attain 150 °C due to high thermal stability and relatively high proton conductivity
at low humidity . Increased operating temperature of such FC provides many
advantages as compared with low-temperature FC with solid polymer membranes,
among which increased tolerance of catalytic materials to CO poisoning is one
of the most important parameters. Moreover, high temperature facilitates the
organization of water management in the fuel cell: the water does not
condense in the liquid phase, and there is no danger of flooding of electrode
pores during operation. Thus, CO-enriched hydrogen produced by the reforming
of natural gas, other hydrocarbon feedstocks, and alcohols can be used for
their work [2, 3].
Nowadays, the most developed polymer electrolyte
membranes for medium temperature FC are based on various condensation
polymers, composite materials, polymers with nitrogen-containing
heterocycles, and complexes of polymers with acids . For medium- and
high-temperature FC, the most studied proton conductive membranes are those
based on polybenzimidazole (PBI) and its derivatives doped by phosphoric acid
[5, 6]. Such membranes show high thermal stability and proton conductivity in
the absence of water. However, the major drawback of these materials is
associated with acid leaching . Condensation of water vapor formed by the
FC operation, for example, by stopping and cooling the battery, leads to
phosphoric acid leaching from the electrolyte and its degradation, and
penetration of acid on the structural elements leads to corrosion of the
latter [8–10]. Thus, the search for new polymer materials that can safely
hold the acid anion is one of the important tasks of developing
This work reports on the analysis of
physicochemical properties including proton conductivity of a new class of
composite proton exchange membranes based on N-phenyl-substituted
polyhexamethylene guanidine (PHMG) and poly-m-phenylene isophthalamide
(phenylone) doped with phosphoric acid (PHMGP-PA) at different temperatures
and environmental humidity. The presence of a strong ionic bond between
protonated PHMGP and phosphoric acid anions allowed one to expect that the
composite material is capable to retain phosphoric acid even in conditions of
high humidity and temperature.
Radnaeva, L. D. Fatty acid composition in the white muscle of Cottoidei
fishes of Lake Baikal reflects their habitat depth/ L. D. Radnaeva, D. V.
Popov, O. Grahl-Nielsen, I. V. Khanaev, S. V. Bazarsadueva, R. Käkelä. //
Environmental Biology of Fishes. – 2017. – V. 100, Issue 12. – P. 1623-1641. https://doi.org/10.1007/s10641-017-0670-6 (IF JСR=1,844
(1,514); Q1). https://www.webofscience.com/wos/woscc/full-record/WOS:000417067100010
Lake Baikal is a unique freshwater environment with maximum depths over
1600 m. The high water pressure at the lakebed strengthens the
solidifying effect of low water temperature on animal tissue lipids, and thus
the effective temperatures in the depths of the lake equal subzero
temperatures in shallow waters. Cottoidei species has colonized the different
water layers of the lake, and developed different ecology and physiology
reflected in their tissue biochemistry. We studied by gas chromatography the
composition of fatty acids (FAs), largely responsible for tissue lipid
physical properties, in the white muscle tissue of 13 species of the
Cottoidei fish; five benthic abyssal, six benthic eurybathic and two
benthopelagic species. The FA profiles reflected habitat depth. The muscles
of the deepest living species contained little polyunsaturated FAs (PUFAs)
and were instead rich in monounsaturated FAs (MUFAs), which may be due to
occasional weak food web links to the PUFA-rich primary producers of the
photic water layer, high MUFA supply from their benthic diet, and conversion
of saturated FAs (SFAs) to MUFAs in the tissues of the fish. Despite the MUFA
percentage among the abyssal species reached even 50% (by weight) of total
FAs, the PUFA percentage still remained above 20% in every species. The
muscle MUFA/SFA ratio correlated negatively with the PUFA content of the fish
muscle, suggesting viscosity control integrating the fluidity contributions
from the dietary PUFAs and potentially endogenous MUFAs.
New solid electrolyte Na9Al(MoO4)6: Structure and Na+ ion conductivity
/ A.A. Savina, V.A. Morozov, A.L. Buzlukov, I.Yu. Arapova, S.Yu. Stefanovich,
Y.V. Baklanova, T.A. Denisova, N.I. Medvedeva, M. Bardet, J. Hadermann, B.I.
Lazoryak, E.G. Khaikina // Chem. Mater. – 2017. – Vol. 29. – P. 8901–8913.
https://doi.org/10.1021/acs.chemmater.7b03989 (IF JCR - 9.466; Q1)
Solid electrolytes are important materials with a wide range of
technological applications. This work reports the crystal structure and
electrical properties of a new solid electrolyte Na9Al(MoO4)6. The monoclinic
Na9Al(MoO4)6 consists of isolated polyhedral [Al(MoO4)6]9− clusters
composed of a central AlO6 octahedron sharing vertices with six MoO4
tetrahedra to form a three-dimensional framework. The AlO6 octahedron also
shares edges with one Na1O6 octahedron and two Na2O6 octahedra. Na3−Na5
atoms are located in the framework cavities. The structure is related to that
of sodium ion conductor II-Na3Fe2(AsO4)3. High-temperature conductivity
measurements revealed that the conductivity (σ) of Na9Al(MoO4)6 at 803
K equals 1.63 × 10−2 S cm−1. The temperature behavior of the 23Na and 27Al
nuclear magnetic resonance spectra and the spin-lattice relaxation rates of
the 23Na nuclei indicate the presence of fast Na+ ion diffusion in the
studied compound. At T<490 K, diffusion occurs by means of Na+ ion jumps
exclusively through the sublattice of Na3−Na5 positions, whereas Na1 and Na2
become involved in the diffusion processes (through chemical exchange with
the Na3−Na5 sublattice) only at higher temperatures.
Luminescence properties upgrading via the structure and cation changing
in AgxEu(2–x)/3WO4 and AgxGd(2–x)/3–0.3Eu0.3WO4 / V.A. Morozov, D. Batuk, M.
Batuk, O.M. Basovich, E.G. Khaikina, D.V. Deyneko, B.I. Lazoryak, I.I.
Leonidov, A.M. Abakumov, J. Hadermann // Chem. Mater. – 2017. – Vol. 29. – P. 8811–8823. https://doi.org/10.1021/acs.chemmater.7b03155
(IF - 9.466; Q1).
The creation and ordering of A-cation vacancies and the effect of
cation substitutions in the scheelite-type framework are investigated as a
factor for controlling the scheelite-type structure and luminescence
properties. AgxEu3+(2−x)/3□(1−2x)/3WO4 and AgxGd(2−x)/3−0.3Eu3+
0.3□(1−2x)/3WO4 (x = 0.5−0) scheelite-type phases were synthesized by a solid
state method, and their structures were investigated using a combination of
transmission electron microscopy techniques and powder synchrotron X-ray
diffraction. Transmission electron microscopy also revealed the (3 + 1)D
incommensurately modulated character of AgxEu3+(2−x)/3□(1−2x)/3WO4 (x =
0.286, 0.2) phases. The crystal
structures of the scheelite-based AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.5,
0.286, 0.2) red phosphors have been refined from high resolution synchrotron
powder X-ray diffraction data. The luminescence properties of all phases
under near-ultraviolet (n-UV) light have been investigated. The excitation
spectra of AgxEu3+(2−x)/3□(1−2x)/3WO4 (x = 0.5, 0.286,
0.2) phosphors show the strongest absorption at 395 nm, which matches
well with the commercially available n-UV-emitting GaN-based LED chip. The
excitation spectra of the Eu2/3□1/3WO4 and Gd0.367Eu0.30□1/3WO4 phases
exhibit the highest contribution of the charge transfer band at 250 nm and
thus the most efficient energy transfer mechanism between the host and the
luminescent ion as compared to direct excitation. The emission spectra of all
samples indicate an intense red emission due to the 5D0 → 7F2 transition of
Eu3+. Concentration dependence of the 5D0 → 7F2 emission for
AgxEu(2−x)/3□(1−2x)/3WO4 samples differs from the same dependence for the
earlier studied NaxEu3+(2−x)/3□(1−2x)/3MoO4 (0 ≤ x ≤ 0.5) phases. The
intensity of the 5D0 → 7F2 emission is reduced almost 7 times with decreasing
x from 0.5 to 0, but it practically does not change in the range from x =
0.286 to x = 0.200. The emission spectra of Gd-containing samples show a
completely different trend as compared to only Eu-containing samples. The
Eu3+ emission under excitation of Eu3+(5L6) level (λex = 395 nm) increases
more than 2.5 times with the increasing Gd3+ concentration from 0.2(x = 0.5)
to 0.3 (x = 0.2) in the AgxGd(2−x)/3−0.3Eu3+0.3□(1−2x)/3WO4, after which it
remains almost constant for higher Gd3+ concentrations.
Cs3LiZn2(WO4)4 and Rb3Li2Ga(MoO4)4: different filled derivatives of the
cation-deficient Cs6Zn5(MoO4)8 structure / S.F. Solodovnikov, Z.A.
Solodovnikova, E.S. Zolotova, Yu.M. Kadyrova, A.A. Savina, S.Yu. Stefanovich,
E.G. Khaikina // Acta Crystallogr. – 2017. – Vol. C73. – C. 73. – P. 946–952.
https://doi.org/10.1107/S205322961701378X (IF JCR - 4.099; Q1).
Two new compounds, namely cubic tricaesium
lithium dizinc tetrakis(tetraoxotungstate), Cs3LiZn2(WO4)4, and tetragonal trirubidium dilithium gallium tetrakis(tetraoxomolybdate),
Rb3Li2Ga(MoO4)4, belong to the
structural family of Cs6Zn5(MoO4)8 (space group I3d, Z = 4), with
a partially incomplete (Zn5/6□1/6) position. In Cs3LiZn2(WO4)4, this position is fully statistically occupied
and in Rb3Li2Ga(MoO4)4, the 2Li + Ga atoms are completely
ordered in two distinct sites of the space group I2d (Z = 4).
In the same way, the crystallographically equivalent A+ cations
Cs, Rb) in Cs6Zn5(MoO4)8, Cs3LiZn2(WO4)4 and isostructural A3LiZn2(MoO4)4 and Cs3LiCo2(MoO4)4 are
divided into two sites in Rb3Li2Ga(MoO4)4, as in other isostructural A3Li2R(MoO4)4 compounds
TlAl, RbAl, CsAl, CsGa, CsFe). In the title structures, the WO4 and
LiO4, GaO4 and MoO4 tetrahedra share corners to form
open three-dimensional frameworks with the caesium or rubidium ions occupying
cuboctahedral cavities. The tetrahedral frameworks are related to that of
mayenite 12CaO·7Al2O3 and isotypic compounds. Comparison
of isostructural Cs3MZn2(MoO4)4 (M = Li,
Na, Ag) and Cs6Zn5(MoO4)8 shows a decrease of the cubic
lattice parameter and an increase in thermal stability with the filling of
the vacancies by Li+ in the Zn position of the Cs6Zn5(MoO4)8 structure, while filling of the
cation vacancies by larger Na+ or Ag+ ions plays a destabilizing role. The
series A3Li2R(MoO4)4 shows
second harmonic generation effects compatible with that of β′-Gd2(MoO4)3 and
may be considered as nonlinear optical materials with a modest nonlinearity.
Synthesis, crystal structures and properties of the new compounds
K7–xAg1+x(XO4)4 (X = Mo, W) / T.S. Spiridonova, S.F. Solodovnikov, A.A.
Savina, Z.A. Solodovnikova, S.Yu. Stefanovich, B.I. Lazoryak, I.V. Korolkov,
E.G. Khaikina // Acta Crysallogr. – 2017.– Vol. C73. – Р. 1071–1077. https://doi.org/10.1107/S2053229617015674
(IF JCR - 4.099; Q1).
Two new isostructural compounds, namely
heptapotassium silver tetrakis (tetraoxomolybdate), K7–xAg1+x(MoO4)4 (0
≤ x ≤ 0.4), and heptapotassium silver
tetrakis(tetraoxotungstate), K7–xAg1+x(WO4)4(0 ≤ x ≤
0.4), have been synthesized and found to crystallize in the polar space group P63mc (Z = 2) with the unit-cell dimensions a = 12.4188 (2) and c = 7.4338 (2) Å for K6.68Ag1.32(MoO4)4 (single-crystal
data), and a = 12.4912 (5) and c = 7.4526 (3) Å for K7Ag(WO4)4 (Rietveld analysis data). Both
structures represent a new structure type, with characteristic [K1(XO4)6]
`pinwheels' of K1O6 octahedra and six XO4 tetrahedra
Mo, W) connected by common opposite faces into columns along the c axes. The octahedral columns are
linked to each other through Ag1O4 tetrahedra along with the K2 and K3/Ag2 polyhedra, forming the polar rods (Ag1O4–X1O4–empty octahedron–Ag1O4). Ag1
is located almost at the centre of the largest face of its coordination tetrahedron
and seems to have some mobility. The new structure type is related to the Ba6Nd2Al4O15 and CaBaSiO4 types, and to other structures of
family. The differential scanning calorimetry (DSC) and second harmonic
generation (SHG) results show that both compounds undergo first-order phase
transformations to high-temperature centrosymmetric phases.
A new double molybdate of erbium and zirconium, its crystalline
structure and properties / B.G. Bazarov, J.G. Bazarova, Yu.L. Tushinova, L.A.
Solovyov, S.G. Dorzhieva, E. Surenjav, J. Temuujin // Journal of Alloys and
Compounds. – 2017. – Vol. 701. – P. 750 – 753. https://doi.org/10.1016/j.jallcom.2017.01.173
(IF - 3.133; Q1).
A new double molybdate of erbium and zirconium, Er2Zr(MoO4)5
was synthesized by a simple solid-state reaction. The crystal structure was
determined using powder X-ray
diffraction data, the Rietveld method and the derivative
difference minimization method (DDM). The new phase crystallizes in the
orthorhombic space groupCmc21.
properties and thermal expansion between 298 and 1073 K were investigated.
The synthesized compound showed an electrical conductivity of about 10−2 S
cm−1 at high temperature.
Exploration of structural, thermal, vibrational and spectroscopic
properties of new noncentrosymmetric double borate Rb3NdB6O12 / V.V. Atuchin,
A.K. Subanakov, A.S. Aleksandrovsky, B.G. Bazarov, J.G. Bazarova, S.G.
Dorzhieva, T.A. Gavrilova, A.S. Krylov, M.S. Molokeev, A.S. Oreshonkov, A.M.
Pugachev, Yu.L. Tushinova, A.P. Yelisseyev // Advanced Powder Technology. –
2017. – V. 28, №5. – C. 1309–1315. https://doi.org/10.1016/j.apt.2017.02.019 (IF
JCR - 2.659; Q1).
New noncentrosymmetric rare earth borate Rb3NdB6O12 is found in the ternary system Rb2O–Nd2O3–B2O3.
The Rb3NdB6O12 powder was fabricated by solid state
synthesis at 1050 K for 72 h and the crystal structure was obtained
by the Rietveld method. Rb3NdB6O12 crystallized
in space group R32 with unit cell parameters a = 13.5236(4),
c = 31.162(1) Å, Z = 3. From DSC measurements, the
reversible phase transition (I type) in Rb3NdB6O12
is observed at 852–936 K. The 200 μm thick tablet is
transparent over the spectral range of 0.3–6.5 μm and the band gap is
found as Eg ∼ 6.29 eV.
Nonlinear optical response of Rb3NdB6O12 tested via SHG is estimated to be
higher than that of K3YB6O12. Blue shift of
Nd luminescent lines is found in comparison with other borates. The
vibrational parameters of Rb3NdB6O12 are evaluated by experimental
Nonstoichiometry in the Systems Na2MoO4–MMoO4 (M = Co, Cd), Crystal
Structures of Na3.36Co1.32(MoO4)3, Na3.13Mn1.43(MoO4)3 and
Na3.72Cd1.14(MoO4)3, Crystal Chemistry, Compositions and Ionic Conductivity
of Alluaudite-type Double Molybdates and Tungstates / S.F. Solodovnikov, Z.A.
Solodovnikova, E.S. Zolotova, V.N. Yudin, O.A. Gulyaeva, Yu.L. Tushinova //
Solid State Chem. – 2017. – Vol. 253. – P. 121–128.
https://doi.org/10.1016/j.jssc.2017.05.031 (IF - 2.299; Q2).
As results of a powder XRD study of sintered samples
of the systems Na2MoO4–MMoO4 (M = Co, Cd) quenched in air from
873 K, the literature data on the phase formation andhomogeneity ranges of nonstoichiometric double molybdatesin
these systems were corrected. The compounds aremonoclinic alluaudite-type
Na4-2xCo1+x(MoO4)3 (0.05 ≤ x ≤ 0.30) and Na4-2xCd1+x(MoO4)3 (0.10 ≤ x ≤ 0.40), orthorhombic lyonsite-type
Na2-2yCo2+y(MoO4)3 (0.05 ≤ y ≤ 0.25), andtriclinic Na2-2zCo2+z(MoO4)3 (0.10 ≤ z ≤ 0.40) of the Na2Mg5(MoO4)6 type. The temperature of the
orthorhombic-to-triclinic phase transition was found to be 943 ± 10 K. Crystal structures of
the alluaudite-type double molybdates (space group C2/c, Z = 4) with cobalt, manganese, and
cadmium were determined. According to the atomic
positionoccupations, the compositions for the crystals were
found as Na3.36Co1.32(MoO4)3 (a = 12.6381(3), b = 13.4888(4), c = 7.1244(2) Å, β = 112.127(1)°, R = 0.0207), Na3.13Mn1.43(MoO4)3(a = 12.7387(3), b = 13.6716(4), c = 7.1904(2) Å, β =
0.0166), and Na3.72Cd1.14(MoO4)3 (a = 12.804(3), b = 13.913(3), c = 7.326(2) Å, β = 112.63(1)°, R = 0.0158). The crystal chemistry and
compositions of the alluaudite-type molybdates and tungstates were
considered and mainly one-dimensional character of the sodium-ion transport
was shown for them. The measured values of the ionic
sintered samples of Na3.6M1.2(MoO4)3 (M = Mg, Ni, Zn, Cd) and Na3.6Mg1.2(WO4)3 exceeds 10−3 S cm−1 at 673 K.
Savina A.A., Solodovnikov S.F., Belov D.A., Solodovnikova Z.A.,
Stefanovich S.Yu., Lazoryak B.I., Khaikina E.G. New alluaudite-related triple
molybdates Na25Cs8R5(MoO4)24 (R = Sc, In): synthesis, crystal structures and
properties // New J. Chem. 2017. Vol. 41. P. 5450–5457. DOI:
10.1039/c7nj00202e (IF JCR - 3.269; Q1)
triple molybdates Na25Cs8R5(MoO4)(24) (R = Sc, In) were prepared as powders
and ceramics by solid state reactions, and their single crystals were also
obtained from melts by spontaneous crystallization. The structures were
determined by single crystal XRD analysis. The electrical conductivity of
ceramics was measured by impedance spectroscopy. The crystal structures were
determined in monoclinic sp. gr. P2(1)/c, a = 14.0069(3) angstrom, b =
12.6498(3) angstrom, c = 28.6491(6) angstrom, beta = 90.007(1)degrees (Sc)
and a = 14.0062(2) angstrom, b = 12.6032(2) angstrom, c = 28.7138(4)
angstrom, b = 90.001(1)degrees (In). Together with triclinic
Na25Cs8Fe5(MoO4)(24), the titled compounds form a distinctive family of
pseudo-orthorhombic alluaudite-related structures with the parent sp. gr.
Pbca. Its structural features are alluaudite-like polyhedral layers composed
of pairs of edge-shared (R, Na)O-6 and NaO6 octahedra connected by bridging
MoO4 tetrahedra. The layers are joined together by means of interlayer MoO4
tetrahedra, thus forming open 3D frameworks with cavities filled with Cs+ and
Na+ ions. The manner of stacking layers is somewhat different from the
alluaudite type. The compounds undergo phase transitions at 668 (Sc) and 725
(In) K accompanied by an abrupt increase of electrical conductivity
presumably Na+-ionic in nature. Above these transitions, the conductivity is
as high as 10(-3) S cm(-1), which makes Na25Cs8R5(MoO4)(24) (R = Sc, In)
promising solid state electrolytes.
Baljinov S.A., Makotchenko V.G., Fedorov V.E., Farion I.A., Kozlova M.N.,
Timashev P.S., Burdukovskii V.F. Convenient approach to making nanocomposites
based on a chitosan–poly(vinyl pyrrolidone) polymer matrix and a graphene
nanofiller // J. Appl. Pol. Sci. – 2017. –
V. 134. – № 27. – P. 45038. DOI 10.1002/app.45038 (IF - 3.125. Q2).
mechanically durable, elastic nanocomposite films were prepared with chitosan
(CS) as the polymer matrix, graphene obtained from highly exfoliated graphite
as the nanofiller, and poly(vinyl pyrrolidone) (PVP) as the stabilizer of the
graphene sheets. The maximum graphene content in the composites without a
loss of uniformity and other useful properties increased up to 4.0 wt %. The
resulting composites were characterized by scanning electron microscopy,
Raman spectroscopy, X-ray diffraction analysis, mechanical testing, and
electrical conductivity testing to determine the effects of the addition of
graphene on the morphology and mechanical and electrical properties of the
CS–PVP–graphene nanocomposite films. In this study, we took an approach to making
nanocomposites from the perspectives of green chemistry, environmental
protection, regenerative medicine, and low cost.
Oxidation of atrazine in aqueous media by
solar- enhanced Fenton-like process involving persulfate and ferrous ion /M.
Khandarkhaeva, A. Batoeva, D. Aseev, M. Sizykh, O. Tsydenova // Ecotoxicology
and Environmental Safety.–2017.–Vol.137, №3.–P.35-41. https://doi.org/10.1016/j.ecoenv.2016.11.013 (IF JCR -
The oxidation of
s-triazines (using atrazine (ATZ) as a model compound) by a solar-enhanced Fenton-like
process involving persulfate and ferrous ion was studied. A flow-through
tubular photoreactor was employed for the experiments. The solar-enhanced
oxidative system involving ferrous ion and persulfate (Solar/S2O82−/Fe2+)
showed the highest ATZ degradation efficiency when compared with other
treatments (unactivated S2O82−, Solar -
sunlight only, S2O82−/Fe2+,
Solar/S2O82−). Complete degradation of ATZ
and 20% reduction in total organic carbon (TOC) content were observed after 30 min of the treatment.
The in situ generated •ОН and SO4–• radicals were shown to be
involved in ATZ oxidation using the radical scavengers methanol and tert-butyl alcohol. Furthermore,
iron compounds were shown to act not only as catalysts but also as
photo-sensitizers, as the introduction of ferrous ion into the reaction
mixture led to an increased absorbance of the solution and expansion of the
absorption spectrum into the longer wavelength spectral region.
Khankhasaeva S., Dashinamzhilova E., Dambueva D.
Oxidative degradation of sulfanilamide catalyzed by Fe/Cu/Al-pillared clays
// Applied Clay Science. –2017. –Vol.146. –P.92-99. https://doi.org/10.1016/j.clay.2017.05.018.
(IF JCR - 3.065, Q1)
degradation of an
antibiotic sulfanilamide with hydrogen peroxide was carried out in the
presence of Fe/Cu/Al-pillared clays as heterogeneous Fenton type catalysts.
Fe/Cu/Al-pillared clays were synthesized by intercalation of layered aluminosilicate containing 95 wt% montmorillonite with mixed polymeric Fe,Cu,Al-polyoxocations
(Al/(Fe + Cu) = 10/1,
OH/(Fe + Cu + Al) = 2.0 mol/mol). The
materials were characterized by chemical analysis, low-temperature nitrogen
adsorption and XRD. Fe/Cu/Al-pillared clays were active catalysts for
sulfanilamide oxidation with hydrogen peroxide in aqueous solutions: in the
presence of these materials oxidation
rate increased significantly
and conversion of sulfanilamide reached 99–100%. The effect of experimental
factors such as H2O2/sulfanilamide molar ratio, the catalyst content, the reaction temperature and
the pH on the conversion of sulfanilamide were studied. The optimal
conditions for the catalytic
sulfanilamide in the presence of Fe/Cu/Al-pillared clay that permit achieving
a high conversion of sulfanilamide and catalyst stability were determined.
The Fe/Cu/Al-pillared clay could be used in four consecutive cycles without
regeneration and loss of activity. The main intermediate products of
sulfanilamide oxidative degradation were sulfanilic acid, benzenesulfonic
acid, p-benzoquinone and aliphatic carboxylic
acids. The results of the study
proved that Fe/Cu/Al-pillared clays were effective catalysts for oxidative
degradation of sulfanilamide in aqueous solutions.
Chalov, S., Thorslund, J., Kasimov, N. et al. The Selenga River delta:
a geochemical barrier protecting Lake Baikal waters // Regional Environmental
Change 17, 2039–2053 (2017). https://doi.org/10.1007/s10113-016-0996-1 (IF JCR - 3,678,
protection of Lake Baikal and the planning of water management measures in
the Selenga River Basin require a comprehensive understanding of the current
state and functioning of the delta’s ecosystem and hydrogeochemical
processes. This is particularly relevant in light of recent and expected
future changes involving both the hydrology and water quality in the Lake Baikal
basin causing spatiotemporal changes in water flow, morphology, and transport
of sediments and metals in the Selenga River delta and thus impacting on
delta barrier functions. The central part of the delta had been characterized
by sediment storage, especially along the main channels, causing a continuous
lift of the delta surface by about 0.75 cm/year−1. Theses morphological
changes have a significant impact on hydrological conditions, with historical
shifts in the bulk discharge from the left to the right parts of the delta
which is distinguished by a relatively high density of wetlands. Regions with
a high density of wetlands and small channels, in contrast to main channel
regions, show a consistent pattern of considerable contaminant filtering and removal
(between 77 and 99 % for key metals), during both high-flow and low-flow
conditions. The removal is associated with a significant concentration
increase (2–3 times) of these substances in the bottom sediment. In
consequence, geomorphological processes, which govern the partitioning of
flow between different channel systems, may therefore directly govern the
barrier function of the delta.
Tykheev, Z.A. Constituents of Essential Oil and Lipid Fraction from the
Aerial Part of Bupleurum
from Different Habitats / Z. A. Tykheev, S. V. Zhigzhitzhapova, F. Zhang, V.
V. Taraskin, O. A. Anenkhonov, L. D. Radnaeva, S. Chen. // Molecules.– 2018. – Issue 23, No.
6, 1496. https://doi.org/10.3390/molecules23061496.
(IF JCR – 4,411; Q2).
The essential oils and lipid fraction extracted from the aerial parts
of Bupleurum scorzonerifolium were determined by a GC-MS method. In
total, up to 67 components were
identified. cis-β-Ocimene, trans-β-ocimene,
limonene, α-pinene, α-copaene, β-elemene, and caryophyllene
oxide were recognized as consistent components of the essential oil extracted
from the aerial parts of B. scorzonerifolium, regardless of the habitat.
The content of these components varied from traces to a significant amount.
The volume of the lipid fraction varied from 2.73 to 9.38%. In total, 23
components were identified, including 20 fatty acids, two sterols, and one
ketone. The major fatty acid components identified were 16:0, 18:2n9, and
18:1n9. The total content of these fatty acids reached up to 76.19%. The
lipid fraction of the aerial parts of B.
scorzonerifolium predominantly contained MUFA and PUFA, which confirmed
the pharmacological value of the species. The main factors affecting the
composition of essential oils and lipid fractions of B.
scorzonerifolium are environmental ones that determine the moisture
supply to the plants in semiarid and arid areas.
Incommensurately modulated structures and luminescence properties of
the AgxSm(2−x)/3WO4 (x = 0.286, 0.2) scheelites as thermographic phosphors /
V. Morozov, D. Deyneko, O. Basovich, E.G. Khaikina, D. Spassky, A. Morozov,
V. Chernyshev, A. Abakumov and J. Hadermann // Chemistry of Materials. –
2018. – Vol. 30. – P. 4788−4798. https://doi.org/10.1021/acs.chemmater.8b02029
(IF JCR - 9.890; Q1).
Ag+ for Sm3+ substitution in the scheelite-type
AgxSm(2–x)/3□(1–2x)/3WO4 tungstates has been
investigated for its influence on the cation-vacancy ordering and
luminescence properties. A solid state method was used to synthesize the x =
0.286 and x = 0.2 compounds, which exhibited (3 + 1)D incommensurately
modulated structures in the transmission electron microscopy study. Their
structures were refined using high resolution synchrotron powder X-ray
diffraction data. Under near-ultraviolet light, both compounds show the
characteristic emission lines for 4G5/2 → 6HJ
(J= 5/2, 7/2, 9/2, and 11/2) transitions of the Sm3+ ions in the
range 550–720 nm, with the J = 9/2 transition at the ∼648 nm region being dominant for all photoluminescence spectra. The
intensities of the 4G5/2 → 6H9/2 and
4G5/2 → 6H7/2 bands have
different temperature dependencies. The emission intensity ratios (R) for
these bands vary reproducibly with temperature, allowing the use of these
materials as thermographic phosphors.
New triple molybdate Rb2AgIn(MoO4)3: synthesis, framework crystal
structure and ion transport behavior / T.S. Spiridonova, S.F. Solodovnikov,
A.A. Savina, Yu.M. Kadyrova, Z.A. Solodovnikova, V.N. Yudin, S.Yu.
Stefanovich, E.G. Khaikina //Acta Crysallogr. С. –2018. – Vol. 74. – N 12. –
P. 1603–1609. https://doi.org/10.1107/S2053229618014717 (IF JCR - 8.678, Q1).
A new triple
molybdate, Rb2Ag1+3xIn1–x(MoO4)3 (0
≤ x ≤ 0.02), was found in the course of a study of the
system Rb2MoO4–Ag2MoO4–In2(MoO4)3 and
was synthesized as both powders and single crystals by solid-state reactions
and spontaneous crystallization from melts. The structure of Rb2Ag1+3xIn1–x(MoO4)3 (x ≈
0.004) is of a new type crystallizing in the centrosymmetric space
group Rc [a = 10.3982 (9), c =
38.858 (4) Å, Z = 12 and R = 0.0225] and
contains (In,Ag)O6 octahedra and distorted Ag1O6 trigonal
prisms linked by common faces to form [Ag(In,Ag)O9] dimers
connected to each other via MoO4 tetrahedra
into an open three-dimensional (3D) framework. Between two adjacent
[Ag(In,Ag)O9] dimers along the c axis, an extra
Ag2O6 trigonal prism with about 1% occupancy was found. The
Ag1O6 and Ag2O6 prisms are located at levels
of z ≈ 1/12, 1/4, 5/12, 7/12, 3/4 and 11/12, and can
facilitate two-dimensional ionic conductivity. The 12-coordinate Rb atoms are
in the framework cavities. The structure of Rb2AgIn(MoO4)3is
a member of the series of rhombohedral 3D framework molybdate structure types
with a ≈ 9–10 Å and long c axes, which
contain rods of face-shared filled and empty coordination polyhedra around
threefold axes. Electrical conductivity of ceramics is measured by impedance
spectroscopy. Rb2AgIn(MoO4)3 undergoes
a `blurred' first-order phase transition at 535 K with increasing electrical
conductivity up to 1.1 × 10−2 S cm−1 at
720 K. Thus, the compound may be of interest for developing new materials
with high ionic conductivity at elevated temperatures.
Thermodynamic properties, Mössbauer
study, and first-principles calculations of TlFe(MoO4)2 /
A.V. Sobolev, E.S. Kozlyakova, I.S. Glazkova, V.A. Morozov, E.A. Ovchenkov,
O.S. Volkova, A.N. Vasiliev, N.S. Ovanesyan, Y.M. Kadyrova, E.G. Khaikina, K.
Molla, B. Rahaman, T. Saha-Dasgupta, S. Kamusella, H.-H. Klauss, I.A.
Presniakov // Journal of Physical Chemistry. C. – 2018. – Vol. 122. – P. 19746−19755.
DOI: 10.1021/acs.jpcc.8b05122 (IF JCR -
report the results of magnetization and specific heat measurements, a57Fe
Mössbauer study of hyperfine interactions and density functional theory
calculations in TlFe(MoO4)2 demonstrating two magnetic phase
transitions at TN2 = 5.7 K and TN1 = 6.2 K. In the asymptotical
critical region TN2 ≤ T ≤ TN1,
the temperature dependence of the average hyperfine magnetic field ⟨Bhf(T)⟩ at the 57Fe nuclei is
well-described by the power law ⟨Bhf(T)⟩ ∝ tβ with the static
critical exponent β ≈
0.37 inherent for a three-dimensional magnet. In this range, the Mössbauer
spectra are described in terms of collinear spin-density-wave with the
inclusion of high-order harmonics. The spectra of the low-temperature phase,
are well-fitted by a single six-line Zeeman pattern reflecting the
equivalence of magnetic sites occupied by Fe3+ ions in an antiferromagnetic
structure. The first-principles calculations allowed estimation of the
strength of main exchange interactions.
Structural and spectroscopic properties of new noncentrosymmetric self-activated borate Rb3EuB6O12 with B5O10 units
/ V.V. Atuchin, A.K. Subanakov, A.S. Aleksandrovsky, B.G. Bazarov, J.G.
Bazarova, T.A. Gavrilova, A.S. Krylov, M.S. Molokeev, A.S.
Oreshonkov, S.Yu. Stefanovich // Materials and Design. – 2018. – Vol. 140. –
P. 488–494. https://doi.org/10.1016/j.matdes.2017.12.004 (IF JCR - 4.525, Q1).
New noncentrosymmetric double borate Rb3EuB6O12 was
designed and synthesized by the solid state reaction method, and its
crystallographic parameters were obtained by Rietveld analysis. This borate
crystallizes in the trigonal space groupR32 with cell parameters a = 13.4604(2)
Å, c = 30.7981(5) Å,Z = 15. Its
structure features a three-dimensional framework composed of the [B5O10]5 − groups
that are bridged by Eu-O polyhedra. The existence of B5O10 group
in the structure was confirmed by vibrational spectroscopy. Rb3EuB6O12 melts
incongruently at 1101 K. The second harmonic generation effect of Rb3EuB6O12 is
16 times higher than that of the α-quartz standard. In the luminescence
spectrum, the domination of a single prominent narrow line from the
hypersensitive 5D0 - 7F2 manifold
of Eu3 + ions is observed, while the 5D0 - 7F1 manifold
and ultranarrow 5D0 - 7F0 line
are of comparable peak intensity. These features are explained by a specific
local symmetry of the Eu3+ ion within the crystal structure
Synthesis of new triple molybdates
K5RZr(MoO4)6 (R = Al, Cr, Fe,
In, Sc) in the K2MoO4– R2(MoO4)3–Zr(MoO4)2
systems, their structure and electrical properties / J.G. Bazarova, A.V.
Logvinova, B.G. Bazarov, Yu.L. Tushinova, S.G. Dorzhieva, J. Temuujin // Journal
of Alloys and Compounds. – 2018. – Vol. 741. – P. 834–839. https://doi.org/10.1016/j.jallcom.2018.01.208 (IF JCR - 3.779, Q1).
relations in the K2MoO4–R2(MoO4)3–Zr(MoO4)2 (R = Al,
Cr, Fe, In, Sc) systems were studied by the method of intersecting cuts. The
formation of new molybdates with
compositions of K5RZr(MoO4)6 (R = Al,
Cr, Fe, In, Sc) were revealed. Synthesized molybdates crystallized in the
hexagonal system, space group P63, Z = 2. Their
thermal characteristics were determined. The electrical properties of K5RZr(MoO4)6(R = Fe,
In) were investigated using impedance spectroscopy(25–106 Hz) in the temperature range
298–973 K. It was found that the dielectric parameters
were temperature dependent and exhibited anomalies at high temperature
(700–900 K) due to the phase transition. The electrical resistivity was
reduced by 6 orders of magnitude from 108 to 102 Om·cm.
Optical spectroscopy of molybdates
with composition Ln2Zr3(MoO4)9
(Ln: Eu, Tb) / D. Sofich, Yu.L. Tushinova, R. Shendrik, B.G. Bazarov,
S.G. Dorzhieva, O.D. Chimitova, J.G. Bazarova // Optical Materials. – 2018. –
Vol. 81. – P. 71–77. https://doi.org/10.1016/j.optmat.2018.05.028
(IF JCR - 2.320, Q2).
This study examined the luminescent properties of systems of double molybdates doped with Eu and Tb — this includes emission, excitation and absorption spectra. The compounds
exhibited bright luminescence in the visible region due to the [Xe]4fn → [Xe]4fn transitions of rare-earth ions. The
luminescence is excited both in the [Xe]4fn → [Xe]4fn bands of the rare-earth ions and in
the wide band in the ultraviolet region related to the transitions within the
Mo-O complex. Because of the energy transfer, the luminescence of Tb3+ and Eu3+ in doubly doped molybdates has had
common excitation energies.
Dudova D.S., Bardakova K.N.,
Kholkhoev B.Ch., Ochirov B.D., Gorenskaia E.N., Farion I.A., Burdukovskii
V.F., Timashev P.S., Minaev N.V., Kupriyanova O.S. UV-laser formation of 3D
structures based on thermally stable heterochain polymers // J. Appl. Pol.
Sci. – 2018. – V. 135. – № 27. – P. 46463. DOI: 10.1002/app.46463 (IF JCR -
approach to making a photopolymeric composition was first elaborated in this
work based on the use of poly-N,N′-(m-phenylene)isophtalamide as the
heterochain polymer matrix together with 4,4′-diphenyl oxide diacrylamide as
the crosslinking agent. Reproducible three-dimensional (3D) objects have been
formed using a laser stereolithograph completed with a laser with wavelength
of 405 nm. According to the thermogravimetric analysis, the thermal stability
of the formed objects could be changed through a control from 260 to 405 °C.
Moreover, it was proven that the tensile strength of samples of the
crosslinked films reached 90.1 ± 3.2 MPa at the elongation at break of
12.4 ± 2.3%, depending on the forming parameters of such samples.
Farion I.A., Burdukovskii V.F., Kholkhoev B.Ch., Timashev P.S.,
Chailakhyan R.K. Functionalization of
chitosan with carboxylic acids and derivatives of them: Synthesis issues and
prospects of practical use: A review // Express Polymer Letters. – 2018. – V. 12. – № 12. – P. 1081-1105. Doi:
10.3144/expresspolymlett.2018.95 (IF JCR - 4.161, Q1).
review is devoted to the current state of the investigation works concerning
chitosan functionalization with carboxylic acids and derivatives of them,
including oxidized carbon nanoparticles such as graphene oxide, oxidized nano
diamonds and oxidized carbon nanotubes. The examples of a use of chitosan
derivatives in the pharmacology, the regenerative medicine, and other areas
Matafonova, G. Recent advances in
application of UV light-emitting diodes for degrading organic pollutants in
water through advanced oxidation processes: A review / G. Matafonova, V.
Batoev // Water Research. – 2018. – Vol.132.– P.177-189. https://doi.org/10.1016/j.watres.2017.12.079
(IF JCR - 7.051,
Over the last
decade, ultraviolet light-emitting diodes (UV LEDs) have attracted
considerable attention as alternative mercury-free UV sources for water
treatment purposes. This review is a
comprehensive analysis of data reported in recent years (mostly, post 2014)
on the application of UV LED-induced advanced oxidation processes (AOPs) to
degrade organic pollutants, primarily dyes, phenols, pharmaceuticals,
insecticides, estrogens and cyanotoxins, in aqueous media.
Heterogeneous TiO2-based photocatalysis in lab grade water using
UVA LEDs is the most frequently applied method for treating organic
contaminants. The effects of controlled periodic illumination, different TiO2-based
nanostructures and reactor types on degradation kinetics and mineralization
are discussed. UVB and UVC LEDs have been used for photo-Fenton,
photo-Fenton-like and UV/H2O2 treatment of pollutants,
primarily, in model aqueous solutions. Notably, UV LED-activated
persulfate/peroxymonosulfate processes were capable of providing degradation
in DOC-containing waters. Wall-plug efficiency, energy-efficiency of UV LEDs
and the energy requirements in terms of Electrical Energy per Order (EEO) are discussed and
compared. Despite the overall high degradation efficiency of the UV LED-based
AOPs, practical implementation is still limited and at
lab scale. More research on real water matrices at more
environmentally relevant concentrations, as well as an estimation of energy
requirements providing fluence-based kinetic data are required.
Mechanism of sodium-ion
diffusion in alluaudite-type Na5Sc(MoO4)4
from NMR experiment and ab initio
calculations / N.I. Medvedeva, A.L. Buzlukov, A.V. Skachkov, A.A. Savina,
V.A. Morozov, Ya.V. Baklanova, I.E. Animitsa, E.G. Khaikina, T.A. Denisova, S.F.
Solodovnikov // Journal of Physical Chemistry. C. – 2019. – V. 123. – P. 4729−4738.
(IF JCR - 4.309, Q1).
The crystal structure, electronic properties, and
sodium diffusion mechanism in Na5Sc(MoO4)4 were
investigated using the powder X-ray diffraction, nuclear magnetic resonance,
and electrical conductivity measurements, as well as ab initio calculations.
Na5Sc(MoO4)4 belongs to the family of
alluaudite-type oxides NaxMy(AO4)3 (M
= In, Sc, Mg, Cd, Zn, Mn, Fe, Co, and Ni; A = Mo, W, P, As, and S), which are
now considered as promising materials for sodium-ion batteries. Our results
demonstrate a considerable difference in the mechanism of Na+ ion
transport in Na5Sc(MoO4)4 and in
previously studied alluaudite oxides, where one-dimensional sodium diffusion
was suggested to occur through channels along the c-axis. The Na+ motion
in Na5Sc(MoO4)4 is found to be rather
two-dimensionally occurring along the bc-plane. We believe that
filling of the M-sublattice plays a key role in the mechanism of Na+ ion
diffusion in alluaudite compounds. In particular, in Na5Sc(MoO4)4 characterized
by a low Sc-occupancy of the M-sublattice, the sodium ions located far from
scandium are the first to be activated with increasing temperature and the
activation energy for their jumps, Ea ≤ 0.3 eV,
has one of the lowest values among Na-conductive materials.
of structural, vibrational and spectroscopic properties of self-activated
orthorhombic double molybdate RbEu(MoO4)2 / V.V. Atuchin, A.S. Aleksandrovsky, B.G. Bazarov, J.G. Bazarova, O.D. Chimitova, Yu.G. Denisenko, T.A. Gavrilova, A.S. Krylov, E.A. Maximovskiy, M.S. Molokeev, A.S. Oreshonkov, A.M. Pugachev, N.V. Surovtsev // Journal of Alloys and
Compounds. – 2019. – Vol. 785. – Р. 692–697. https://doi.org/10.1016/j.jallcom.2019.01.013 (IF JCR - 4.175, Q1).
synthesized by the two-step solid state reaction method. The crystal structure
of RbEu(MoO4)2 is defined by Rietveld analysis in
space group Pbcn with cell parameters a = 5.13502(5),
b = 18.8581(2) and c = 8.12849(7) Å, V = 787.13(1) Å3, Z = 4 (RB = 0.86%).
This molybdate possesses its phase
transition at 817 K and melts at 1250 K. The Raman spectra were measured with
the excitation at λ = 1064 and 514.5 nm. The photoluminescence spectrum is evaluated under
the excitation at 514.5 nm. The absolute domination of hypersensitive 5D0→7F2 transition
is observed. The ultranarrow 5D0→7F0 transition
in RbEu(MoO4)2 is positioned at 580.2 nm being
0.2 nm blue shifted, with respect to that in Eu2(MoO4)3
From Aggregates to Porous
Three-Dimensional Scaffolds through a Mechanochemical Approach to Design
Photosensitive Chitosan Derivatives / K.N. Bardakova, T.A. Akopova, A.V.
Kurkov, G. P. Goncharuk , D. V.
Butnaru, V. F. Burdukovskii, A. A. Antoshin , I. A. Farion, T. M. Zharikova,
A. B. Shekhter, V. I. Yusupov, P. S. Timashev, Y. A. Rochev // Marine Drugs.
– 2019. – V. 17. – N 1. – Article Number 48. https://doi.org/10.3390/md17010048 (IF JCR - 4.217, Q1).
The crustacean processing
industry produces large quantities of waste by-products (up to 70%). Such
wastes could be used as raw materials for producing chitosan, a
polysaccharide with a unique set of biochemical properties. However, the
preparation methods and the long-term stability of chitosan-based products
limit their application in biomedicine. In this study, different scale
structures, such as aggregates, photo-crosslinked films, and 3D scaffolds
based on mechanochemically-modified chitosan derivatives, were successfully
formed. Dynamic light scattering revealed that aggregation of chitosan
derivatives becomes more pronounced with an increase in the number of
hydrophobic substituents. Although the results of the mechanical testing
revealed that the plasticity of photo-crosslinked films was 5–8% higher than
that for the initial chitosan films, their tensile strength remained
unchanged. Different types of polymer scaffolds, such as flexible and porous
ones, were developed by laser stereolithography. In vivo studies of the
formed structures showed no dystrophic and necrobiotic changes, which proves
their biocompatibility. Moreover, the wavelet analysis was used to show that
the areas of chitosan film degradation were periodic. Comparing the results
of the wavelet analysis and X-ray diffraction data, we have concluded that
degradation occurs within less ordered amorphous regions in the polymer bulk.
Shpichka A., Butnaru D, Bezrukov E.A., Sukhanov R.B., Atala A.,
Burdukovskii V.F., Timashev P.S. Skin tissue regeneration for burn injury //
Stem cell research & therapy. – 2019. – V. 10. – № 94. DOI:
10.1186/s13287-019-1203-3. (IF JCR - 4.659, Q1).
The skin is the largest
organ of the body, which meets the environment most directly. Thus, the skin
is vulnerable to various damages, particularly burn injury. Skin wound
healing is a serious interaction between cell types, cytokines, mediators,
the neurovascular system, and matrix remodeling. Tissue regeneration
technology remarkably enhances skin repair via re-epidermalization,
epidermal-stromal cell interactions, angiogenesis, and inhabitation of
hypertrophic scars and keloids. The success rates of skin healing for burn
injuries have significantly increased with the use of various skin
substitutes. In this review, we discuss skin replacement with cells, growth
factors, scaffolds, or cell-seeded scaffolds for skin tissue reconstruction
and also compare the high efficacy and cost-effectiveness of each therapy. We
describe the essentials, achievements, and challenges of cell-based therapy
in reducing scar formation and improving burn injury treatment.
Batoeva A., Sizykh M., Aseev D., Garkusheva N. Photo-Fenton-like degradation
of bisphenol A by persulfate and solar irradiation // Journal of
Environmental Management.–2019.–Vol.249.–109348. https://doi.org/10.1016/j.jenvman.2019.109348 (IF JCR - 4.005, Q1)
This work evaluates the feasibility of
a solar-enhanced Fenton-like process using S2O82− (PS)
and Fe2+ for the elimination of BPA,
a model endocrine-disruption compound. This comparative study of BPA removal
showed that among the approaches employed, the effectiveness of BPA
degradation (10 mg/L) decreased in the order: Solar/PS/Fe2+>
Solar/PS > PS/Fe2+> Solar/Fe2+> Solar.
degradation of BPA was achieved by Solar/PS/Fe2+ treatment
at a [PS]:[BPA] ratio of 20 in less than t30W 5 in deionised
water. The high efficiency of the Solar/PS/Fe2+ process
revealed a synergistic
effect (ϕ = 2.38) between the applied
activation agents on the formation of reactive
oxygen species (ROS) and subsequent decomposition of
BPA. The treatment was accompanied by total
organic carbon (TOC) removal (44%) in 45 min.
Sequential generation of reactive oxygen species has made Solar/PS/Fe2+ a
kinetically effective process for removing BPA without accumulation of toxic
intermediates. The reaction rate followed pseudo-first-order kinetics that
increased with increasing PS and Fe2+ concentrations.
Experimental evidence suggests that exposure to solar
irradiation maintains suitable quantities of free Fe2+ in
the reaction mixture, even at low catalyst concentrations (the molar
ratio of [PS]:[Fe2+] varied from 1:0.01
to 1:0.08). The effects of HCO3−, SO42−,
and Cl− were also examined. As expected, HCO3− and
SO42− inhibited BPA oxidation. The effect of Cl− on
the oxidation efficiency of BPA in Fenton-like systems depends not only on
actual Cl− concentrations but it is also highly influenced by
molar ratios of Cl− to oxidant and catalyst. Inhibition,
which was caused by Cl− in the mM range can be overcome by
prolonging the reaction time or increasing the initial Fe2+concentration.
Finally, the efficiency of
Solar/PS/Fe2+ process was examined in diluted natural surface
water and wastewater effluent. On eliminating the buffering action of HCO3−/CO32− ions
by lowering the pH value to 4.5, complete BPA degradation was achieved in all
real water matrices.
Simultaneous atrazine degradation and E.
coli inactivation by UV/S2O82-/Fe2+
process under KrCl excilamp (222 nm) irradiation / S. Popova, G. Matafonova,
V. Batoev // Ecotoxicology and Environmental Safety. – 2019. – Vol.169. – P. 169-177.
DOI: 10.1016/j.ecoenv.2018.11.014 (IF JCR - 3.974,
This study is the first to reveal that the
iron-catalyzed photo-activation of persulfate (UV/PS/Fe2+system)
under mercury-free KrCl excilamp irradiation (222 nm) is capable of
simultaneous degradation of an organic pollutant and inactivation of a
microorganism in aqueous media using the herbicide atrazine (ATZ) and E. coli as model contaminants,
respectively. Deionized water, natural water and wastewater effluents,
contaminated with 4 mg/L ATZ and/or 105 CFU/mL E. coli, were sequentially treated by
direct UV, UV/PS and UV/PS/Fe2+ processes. Lowering the pH to 3.5 accelerated both the degradation and inactivation
during the UV/PS/Fe2+
treatment of natural water. Comparison
of the apparent UV
dose-based pseudo first-order rate constants showed the negative effect of E. coli on ATZ degradation by
decreasing rates in all of the examined water matrices. This can be due to
the competitive effect between ATZ and bacterial cells for reactive oxygen
species (ROS). By contrast, E. coli in
the presence of ATZ was inactivated faster
in natural water and wastewater (but not in deionized water), as compared to
the case without ATZ. A scheme of possible synergistic inactivation under ROS exposure in
water, containing ATZ, natural organic matter and chloride ions as primary
constituents, was proposed. Radical
scavenging experiments showed a major contribution of SO4•- to ATZ degradation by UV/PS/Fe2+ treatment of deionized water and natural water. The UV doses, required for 90% removal of
ATZ from natural water and wastewater, achieve 160 mJ/cm2 (pH 5.5)
and concurrently provide 99.99% E. coli
inactivation. These results make the UV/PS/Fe2+ system with narrow
band UV light sources promising for simultaneous water treatment and
Batoev V. Review on low- and high-frequency sonolytic, sonophotolytic and
sonophotochemical processes for inactivating pathogenic microorganisms in
aqueous media// Water Research. – 2019. – Vol.166. – 115085. https://doi.org/10.1016/j.watres.2019.115085 (IF JCR - 7.051, Q1)
ultrasound-based advanced oxidation processes (AOPs) are gaining considerable
research attention for water treatment and disinfection. Compared to
low-frequency ultrasound (LFUS, <100 kHz), high-frequency ultrasound
(HFUS, >100 kHz and MHz range) for water disinfection remains much less
investigated. The present review aims at surveying and discussing literature
data on microbial inactivation in non-food aqueous media using HFUS alone and
with AOPs. More specifically, the review covers sonophotolytic (US/UV)
processes under sequential and simultaneous modes as well as
sonophotochemical processes, where both low and high frequencies were
applied. Addressing a state-of-the-art biomedical research, we have attempted
to provide more insight into mechanical and sonochemical mechanisms of
inactivation under ultrasonic exposure. Sonoporation, intracellular
generation of reactive oxygen species (ROS), energy stimulation of aquaporins
to deliver ROS, and injection of extracellular ROS into sonoporated cells
have all been identified as primary ways of inactivation. Application of
ultrasound in the 0.2-2 MHz range and mercury-free light sources to support
the Minamata Convention on
Mercury is an ongoing challenge for
effective elimination of microbial pathogens from water and
wastewater through sonophotolytic and
Namsrai, O., Ochir, A., Baast, O., van Genderen, J.L., Muhar, A.,
Erdeni, S., Wang, J., Davaasuren, D., & Chonokhuu, S. (2019). Evaluating
the management effectiveness of protected areas in Mongolia using the
management effectiveness tracking tool. Environmental management, 63(2),
249-259. DOI:10.1007/s00267-018-1124-4. (IF JCR - 2.376, Q2)
The importance of management
increases in the context of numerous and intensive inner and outer pressures
on Protected Areas (PAs). The need to assess the management effectiveness
(ME) in protected areas is increasing around the world. The ME assessment helps
to improve the management of PAs and to develop a rational, long-term action
plan. This study was conducted using the World Wildlife Fund for nature (WWF)
Management Effectiveness Tracking Tools methodology (METT) to evaluate the ME
of six PAs in central and eastern regions of Mongolia. The main purpose of
this study was to assess ME and identify common threats of PAs across
different natural zones and administrative areas in Mongolia. The results of
this evaluation indicate that, the main threats faced by PAs in Mongolia are:
(i) degradation of ecosystems, (ii) environmental pollution, and (iii)
habitat fragmentation, resulting from over-exploitation and inappropriate use
of natural resources. All six PAs examined have clear management goals and
management decision-making systems however, their ME scores differ
significantly. This research suggests that the administrative features of the
individual PA influence management effectiveness and problems in the
efficient implementation of management still need to be resolved.
Zhigzhitzhapova, S.V. Composition and antioxidant
activity of the essential oil of Artemisia
annua L /S.V. Zhigzhitzhapova, E.P. Dylenova, S.M. Gulyaev, T.E. Randalova, V.V. Taraskin, Z.A. Tykheev, L. D. Radnaeva //
Natural Product Research. – 2020. – Vol. 34, Issue 18. – P. 2668-2671. https://doi.org/10.1080/14786419.2018.1548461 (JCR
– 2,861 (1.928); Q2). https://www.tandfonline.com/doi/full/10.1080/14786419.2018.1548461
Artemisia annua L. is an annual Eurasian
desert-steppe plant. The composition of essential oils found
in Artemisia annua from Russian (Buryatian) flora was analyzed in
this work using gas chromatography mass-spectrometry method. Artemisia ketone,
β-selinene, caryophyllene, caryophyllene oxide, germacrene D were the main
components of the analyzed essential oils. The comparison of own and
literature data showed that the essential oils of A.
annua conditionally could be divided into “Asian” and “European” groups.
Our samples, referring to “Asian” profile, exhibited higher antiradical
activity in comparison with data from previously published studies.
Radnaeva, L.D. First
data on lipids and microorganisms of deepwater endemic sponge Baikalospongia
intermedia and sediments from hydrothermal discharge area of the Frolikha Bay
(North Baikal, Siberia)/ L.D. Radnaeva, S.V. Bazarsadueva, V.V. Taraskin,
A.K. Tulokhonov // Journal of Great Lakes Research. – 2020. – Vol. 46, issue
1. – P. 67-74 https://doi.org/10.1016/j.jglr.2019.09.021. (JCR
– 2,48 (1,933); Q2). https://www.sciencedirect.com/science/article/abs/pii/S0380133019301832?via%3Dihub
In this report, we
study lipid components (fatty acids with various degrees of
unsaturation, aldehydes and sterols) of deep-water sponges Baikalospongia
intermedia and sediments sampled using deep-water manned
submersibles “Mir” at a hydrothermal vent of Frolikha Bay at depths of 400–450 m. It was
found that unsaturated fatty acids predominate in the FA-composition of the
sponges: very long chain demospongic acid 26:3, as well as monounsaturated
24:1 and isomers of acids 16:1 and 18:1. Among the saturated fatty acids in
addition to the stearic 18:0, palmitic 16:0 and heptadecanoic 17:0 acids,
significant amounts of acids of microbial origin (iso-palmitic i16:0,
isostearic i18:0, oxy-stearic 10 h18) were detected. Using the method of mass
spectrometry of microbial markers, we conclude, that the main microbial
components of sponges B. intermedia and sediments from
Frolikha Bay are methanotrophic microorganisms.
Tykheev, Zh. A. Do
Compositions of Lipid Fraction Correspond to Species Differentiation in Bupleurum L. (Apiaceae)? / Zh. A. Tykheev, O. A. Anenkhonov, S. V. Zhigzhitzhapova,V. V. Taraskin, L. D.
Radnaeva, F. Zhang // Plants.
– 2020. – Vol. 9(11), No.1407. https://doi.org/10.3390/plants9111407. (JCR – 3,935 (2.762), Q1). https://www.mdpi.com/2223-7747/9/11/1407
Bupleurum L. has been
widely used in various medical systems as an agent with a wide range of
activities. The qualitative composition and content of lipid fraction
components of the aerial parts of B. longifolium and B.
chinense were elucidated in this work. The available data on the fatty acids
(FAs) in Bupleurum plants were compiled and compared with species
differentiation in the genus. As a result, the content of FAs in the
studied Bupleurum plant species only partially corresponded to the
species differentiation and, in some cases, contradicted it. The prognostic
value of Bupleurum’s species differentiation for the identification of
the potential composition of FAs was insignificant, and it was limited only
by particular groups of species. This suggests that a complete phytochemical
study of Bupleurum species needs to be conducted to determine the
composition of FAs and to identify which species have a similar composition.
B.M.,Chromones and coumarins from Saposhnikovia divaricata (Turcz.) Schischk.
Growing in Buryatia and Mongolia and their cytotoxicity / B.M. Urbagarova,
E.E. Shults, V.V. Taraskin, L.D. Radnaeva, T.N. Petrova, T.V. Rybalova, T.S.
Frolova, A.G. Pokrovskii, J. Ganbaatar // Journal of Ethnopharmacology –2020.
– Vol. 261. № 112517. https://doi.org/10.1016/j.jep.2019.112517. (JCR – 4,360 (3.69); Q1). https://www.sciencedirect.com/science/article/pii/S0378874119337778?via%3Dihub
Saposhnikovia divaricata (family Apiaceae) a traditional medicinal plant distributed in
many provinces of China, is well known for the pharmaceutical value and has
been used for rheumatic arthritis, and anxiety in children. Antiviral,
antioxidant and antiproliferative activities were also mentioned. The
application of this plant are recorded in the Chinese Medicine (CM) classical
text the Shen Nong's Materia Medica (Shen Nong Ben Cao Jing). In this monograph S.
divaricata (syn Radix Ledebouriella divaricata) is
graded as a premium-grade herb, with their broad-spectrum of therapeutic
applications for the treatment of cough, common cold, arthralgia, as well as
in rheumatic disorders.
Total of 15 individual
compounds: coumarins scopoletin 2, bergapten 3,
isoimperatorin 4, marmesin 5, (+)-decursinol 9,
(−)-praeruptorin B 10, oxypeucedanin hydrate 11,
chromones: hamaudol 6, cimifugin 7, 5-О-methylvisamminol 8,
chromone glycosides: prim-O-glucosylcimifugin 12, sec-O-glucosylhamaudol 13,
4′-O-β-D-glucopyranosyl-5-О-methylvisamminol 14, 4'-O-β-D-glucopyranosylvisamminol
(15) and also polyyne compound panaxinol 1 were
isolated and characterized. The structure of dihydropyranocoumarin 10 was
confirmed by X-ray diffraction analyses. HPLC-UV method was used for
determination of the content of most abundant chromones 7, 12 and 14 in
the roots of S. divaricata, collected in
Mongolia. Compounds 3-11 and 13, 14 were
evaluated for their cytotoxicity with respect to model cancer cell
lines. All the compounds were non-toxic in the hemolysis test. Conclusion:
This report about the phytochemical profiles of S. divaricata growing
in Mongolia and Buryatia led to the identification of 14 compounds including
coumarins and chromones. The available coumarins and chromones may serve
as new leads for the discovery of anticancer drugs.
Coexistence of three types of sodium motion
in double molybdate Na9Sc(MoO4)6: 23Na
and 45Sc NMR data and ab initio calculations /A.L. Buzlukov, I.Yu. Arapova, Ya.V. Baklanova, N.I. Medvedeva, T.A.
Denisova, A.A. Savina, B.I. Lazoryak, E.G. Khaikina, M. Bardet // Phys. Chem. Chem. Phys. – 2020. – Vol. 22. – Р.
144–154. DOI: 10.1039/c9cp05249f (IF JCR - 6.732, Q1).
The rechargeable Na-ion batteries attract
much attention as an alternative to the widely used but expensive Li-ion
batteries. The search for materials with high sodium diffusion is important
for the development of solid state electrolytes. We present the results of
experimental and ab initio studies of the Na-ion diffusion
mechanism in Na9Sc(MoO4)6. The ion conductivity
reaches the value of 3.6 × 10−2 S
cm−1 at T ∼ 850 K. The 23Na and 45Sc NMR data reveal the
coexistence of three different types of Na-ion motion in the temperature
range from 300 to 750 K. They are activated at different temperatures and are
characterized by substantially different dynamics parameters. These features
are confirmed by ab initio calculations of activation barriers
for sodium diffusion along various paths.
of the structural and vibrational properties of the ternary molybdate Tl5BiHf(MoO4)6
with Isolated MoO4 units and Tl+ conductivity /
// Inorg. Chem. – 2020. – Vol. 59. –
https://doi.org/10.1021/acs.inorgchem.0c01762 (IF JCR -
The phase relations in the
subsolidus region of the Tl2MoO4–Bi2(MoO4)3–Hf(MoO4)2 system
were studied with the “intersecting cuts” method. The formation of the novel
ternary molybdate Tl5BiHf(MoO4)6 is
found in this ternary system. The compound has a phase transition at Tpt =
731 K (ΔH =
−3.15 J/g) and melts at Tm = 871 K (ΔH =
−41.71 J/g), as determined by a thermal analysis. Tl5BiHf(MoO4)6 single
crystals were obtained by the spontaneous nucleation method. The crystal
structure of Tl5BiHf(MoO4)6was revealed by
structure analysis methods. This molybdate crystallizes in the trigonal space
group R3̅c with the unit cell
parameters a = 10.6801(4) Å, c =
38.5518(14) Å, V = 3808.3(2) Å3, and Z =
6. The vibrational characteristics of Tl5BiHf(MoO4)6 were
determined by Raman spectroscopy. The Tl5BiHf(MoO4)6 conductivity
was measured at frequencies of 0.1, 1.0, and 10 kHz in the temperature range
of 293–773 K; in this temperature range, the conductivity level was 10–12–10–7 S/cm.
Thallium ionic conductivity of new thallium indium hafnium molybdate
ceramics / V.G. Grossman, J.G. Bazarova, M.S. Molokeev, B.G. Bazarov //
Ionics. – 2020. – Vol. 26, № 12. – P. 6157– 6165. Doi:
10.1007/s11581-020-03739-7 (IF JCR -
In the process of studying the system
Tl2MoO4–In2(MoO4)3–Hf(MoO4)2, a new thallium
indium hafnium molybdate was found. The crystal structure of the molybdate Tl5InHf(MoO4)6 was determined in the
centrosymmetric space groupR3¯¯¯3¯c (a = 10.63893 (5)
Å, c = 38.1447(3) Å; V = 3739.04 (4) Å3, Z = 6). The structure is a
three-dimensional framework consisting of alternating (Hf,In)O6-octahedra
connected by МоО4-tetrahedra.
Each octahedron has common vertices with tetrahedra. The atoms arranged in
this way form channels extended along with the a and b axes, in which thallium atoms are
located. The conductivity behavior of Tl5InHf(MoO4)6 ceramics was studied in the
temperature range from 300 to 870 K. The conductivity of the heavy
cations of thallium is activated with increasing temperature.
New triple molybdate K5ScHf(MoO4)6:
Synthesis, properties, structure and phase equilibria in the M2MoO4–Sc2(MoO4)3–Hf(MoO4)2
(M = Li, K) systems / V.G.
Grossman, J.G. Bazarova, M.S. Molokeev, B.G. Bazarov // J. Solid State Chem. – 2020. – Vol. 283. – P. 121143. https://doi.org/10.1016/j.jssc.2019.121143 (IF JCR - 2.291, Q2).
Subsolidus phase relations in the M2MoO4–Sc2(MoO4)3–Hf(MoO4)2 (M = Li, K) systems have been studied by the
method of “intersecting cuts”. No new triple molybdates have been identified in the Li2MoO4–Sc2(MoO4)3–Hf(MoO4)2system
and a new triple molybdate K5ScHf(MoO4)6 is formed in the K2MoO4–Sc2(MoO4)3–Hf(MoO4)2 system. The structure of K5ScHf(MoO4)6,
have been determined in space group R3‾cthrough
Rietveld analysis of X-ray powder diffraction data. The melting point of
molybdate is 999 K. The compound
has high ion conductivity (about 10−3 S cm−1).
double holmium borates: Rb3HoB6O12 and Rb3Ho2B3O9
/A.K. Subanakov, E.V. Kovtunets, B.G. Bazarov, S.G. Dorzhieva, J.G. Bazarova // Solid State Sciences. –
2020. – Vol. 105. – P. 106231. 10.1016/j.solidstatesciences.2020.106231 (IF JCR - 2.155, Q2).
borates Rb3HoB6O12, Rb3Ho2B3O9
were newly synthesized by the sol–gel method and with solid state reactions.
The crystal structures were determined from powder X-ray diffraction data.
Rietveld's refinement of Rb3HoB6O12 showed
the following: R32, a = 13.4078 (2) Å, c = 30.3398 (4) Å, Z = 15. Rb3Ho2B3O9
species revealed: Pna21, a = 8.7139 (1) Å, b = 9.5760 (2) Å, c = 12.22335 (1)
Å, Z = 2. Rb3HoB6O12 and Rb3Ho2B3O9
incongruently and congruently melted at 818 °C and 908 °C, respectively. The
phase transition for Rb3HoB6O12 was
established at 715 °C. The existence of B5O10 group in
Rb3HoB6O12 crystal structure was confirmed
by an IR analysis.
Sodium-ion diffusion in alluaudite Na5In(MoO4)4
/ A.L. Buzlukova, N.I. Medvedeva, Y.V. Baklanova,
A.V. Skachkov, A.A. Savina,
I.E. Animitsa, Т.А. Denisova , E.G.
Khaikina // Solid State Ionics.
– 2020. – Vol. 351. – P. 115328. Doi: 10.1016/j.ssi.2020.115328. (IF JCR - 2.886, Q2).
Alluaudite phases are very attractive as
both cathode and electrolyte materials for rechargeable sodium-ion batteries.
In this work, the combined experimental and DFT studies have been performed
to establish the diffusion mechanism in alluaudite-like compound Na5In(MoO4)4.
The ionic conductivity was found to reach 3.3 × 10−4 S/сm
at 687 K, with an activation energy of 0.66 eV. The sodium
diffusion mechanisms have been revealed from the analysis of the 23Na NMR spectra along
with the DFT estimations of Na-ion migration barriers. Our results predict
that one-dimensional diffusion of sodium in the separate channels along the c-axis is accompanied by
the cross-linking jumps providing two-dimensional diffusion in the bc-plane. It is clearly
demonstrated that the indium deficiency favors 2D diffusion, but sharply
increases the energy barrier for 1D diffusion. Comparison of our results for
Na5In(MoO4)4 and related Na5Sc(MoO4)4 shows that the type and deficiency
of M-metal in the NaxMy(MoO4)z alluaudites can control the sodium
diffusion. The present work highlights the key aspects of cation influence on
the diffusion properties in alluaudite materials.
Nephrite-bearing mining waste as a promising
mineral additive in the production of new cement types / L.I.
Khudyakova, E.V. Kislov, P.L. Paleev, I.Yu. Kotova // Minerals. – 2020. – Vol. 10, № 5. – P. 394–406.
Doi: 10.3390/min10050394 (IF
JCR - 2.618, Q2).
Agrowing demand for
products made of jewelry and ornamental stones, including nephrite, requires
an increase in mining volume. However, only less than 30% of the extracted
raw material is suitable for processing. The rest of the low grade nephrites
are substandard and unclaimed, and they negatively a_ect various life
spheres. In this regard, their involvement in industrial turnover is an
actual task. One of the directions of mining waste use is production of
building materials, in particular, cements. The low grade nephrite can act
here as mineral additives. In the course of the research, the optimal amount
of low grade nephrite waste additive was determined, which is 30% of the
cement mass. The grinding time of a raw mix is 10 min. It was found that
introduction of the additive a_ects the hydration activity of cement
compositions. Compressive strength of the mixed cement is 25% higher than
that of the control sample. At the same time, new phases in the hydrated cement
were not recorded. Good physical and mechanical properties of the obtained
cements are achieved when hardening in normal humidity conditions. Heat and
humidity treatments do not facilitate the hydration processes in binary systems.
The conducted studies have shown that low grade nephrite can be used as
mineral additives in cement production. This will allow development of not
only a new type of product, but also reduction of the negative impact of
cement production on the environment.
Ochirov B.D., Gorenskaia E.N., Kholkhoev B.Ch., Ayurova O.Zh., Burdukovskii
V.F. Synthesis and thermo-oxidative
degradation of acyclic polyimides // Polymer. – 2020. – V. 205. – 122692. Doi: 10.1016/j.polymer.2020.122692
(IF JCR - 4.430, Q1).
For the first time,
film-forming aromatic acyclic polyimides were obtained as a result of in situ
rearrangement or as a result of heat treatment of polycarboxyimidates by the
Mumm-Hess mechanism. Intermediate polycarboxyimidates were prepared using the
acid-catalyzed reaction of dicarboxylic acids and dinitriles in ionic
liquids. The probable mechanism and the corresponding kinetic parameters of
thermooxidative decomposition of acyclic polyimides were determined using
NetzschThermokinetics 3 – multidimensional nonlinear regression software.
Matafonova G., Batoev V. Dual frequency ultrasound:
Strengths and shortcomings to water treatment and disinfection // Water Research.
– 2020. –Vol. 182. –116016.
10.1016/j.watres.2020.116016 (IF JCR - 9.130, Q1)
the early 2000s, dual-frequency ultrasound (DFUS) has received much attention
for synergistically enhanced elimination of organic pollutants and pathogenic
microorganisms from water. In the present review, we have surveyed recent
developments in acoustic physics to elucidate the mechanism of synergistic
effect under exposure of aqueous media to DFUS. Briefly, the nonlinear
dynamics of microbubbles upon DFUS exposure produces additional frequencies,
such as harmonics, subharmonics, ultraharmonics and combination frequencies.
These increase the probability of bubbles collapse, thereby enhancing
cavitation and generating more reactive oxygen species (ROS) for advanced
oxidation processes (AOPs). Further, literature data on ROS generation,
chemical degradation and microbial inactivation in aqueous media through DFUS
alone and DFUS-based AOPs (involving oxidants or catalysts) have been
discussed. In this regard, optimal frequency combination, sonoreactor type
and transducer arrangement appear to be key parameters for achieving a high
synergistic effect. Strengths and shortcomings of DFUS to water treatment and
disinfection have been identified and future research directions have been
proposed. Though most studies were conducted on pure (matrix-free) aqueous solutions,
these AOPs could be applicable for treating real waters.
Badmaeva S. Removal of p-aminobenzenesulfanilamide from water solutions by
catalytic photo-oxidation over Fe-pillared clay // Water Research. –2020.
–Vol.185. –116212. https://doi.org/10.1016/j.watres.2020.116212. (IF JCR - 9.130, Q1)
photo-oxidation of p-aminobenzenesulfanilnamide (ABS) with hydrogen peroxide
in the presence of Fe-pillared clay as heterogeneous catalyst has been
investigated under UV-irradiation (λmax = 254 nm).
Fe-pillared clay was synthesized by intercalating the iron
polyhydroxycomplexes into the interlayer space of a natural layered
aluminosilicate - montmorillonite and a subsequent heat treatment at
500 °C. The catalyst was characterized by chemical analysis, low
temperature nitrogen adsorption and XRD. The kinetics of photocatalytic
oxidative degradation of ABS in aqueous solutions under various experimental
conditions was studied. The dependence of the photo-oxidation rate on such
experimental factors as pH, hydrogen peroxide concentration and catalyst
content was established. The conversion of ABS was 100% and the
mineralization efficiency was 52.3% at optimal conditions. The intermediate
products of ABS photo-oxidation identified by HPLC were a sulfanilic acid,
benzenesulfonamide, benzenesulfonic acid, hydroquinone, pyrocatechol,
benzoquinone and aliphatic acids. Fe-pillared clay remained highly active in
three consecutive catalytic cycles without regeneration. The results of the
study suggested that the heterogeneous photo-system «Fe-pillared clay/H2O2/UV»
was effective in the oxidative degradation of aminobenzenesulfanilnamide.
This system may be of interest for use in organic wastewater treatment
Bilgaev, A., Dong, S., Li, F., Cheng, H., Sadykova, E., &
Mikheeva, A. (2020). Assessment of the current eco-socio-economic situation
of the Baikal region (Russia) from the perspective of the green economy
development. Sustainability, 12(9), 3767. DOI:10.3390/su12093767.
(IF JCR - 2.576, Q2)
aimed at establishing the relationship between economic development and
non-violation of the environment and developing optimal ways of their
interaction is possible only by studying the features of regional
development, which requires a comprehensive assessment of the ecological and
socio-economic situation of the territories. The Baikal region includes
Irkutsk Oblast, Republic of Buryatia, and Zabaykalsky Krai and occupies an
exceptional place in Russia, due to Lake Baikal and unique natural features.
The results of the assessment of the state of purity and quality of the
environment indicate the emerging negative trends associated with water
pollution, atmospheric air, and waste disposal in the Baikal region.
Therefore, this article proposes the solutions to the problems in achieving
sustainable development based on the implementation of the principles of the
green economy, providing recommendations on how to reverse the current
ecological and socio-economic situation of the Baikal region in a positive
direction. Obtained practical assessments are essential for solving the
problems of conservation and creating favorable conditions for the life of
the population. Implementation of key government regulatory measures and
changing existing approaches to managing the region based on the principles
of the green economy will reduce the level of anthropogenic pressure on the
61. Sanzheev, E.D., Mikheeva, A.S., Osodoev, P.V., Batomunkuev,
V.S., & Tulokhonov, A.K. (2020). Theoretical Approaches and Practical
Assessment of Socio-Economic Effects of Desertification in Mongolia.
International Journal of Environmental Research and Public Health, 17(11),
4068. DOI:10.3390/ijerph17114068. (IF JCR - 2.849, Q1)
In this paper, we
consider the effects of desertification in Mongolia, where the area of
degraded land has increased significantly in the recent decade. Currently,
almost the entire territory of the country is subject to varying degrees of
degradation. The intensity of the desertification processes in different
natural zones is influenced by both natural climatic and anthropogenic
factors. The purpose of this study is to evaluate the impact of
desertification on environmental and socio-economic living conditions, as
well as on living standards of the local population. In this work, for the
first time, the socio-economic aspects of desertification have been studied
on a common methodological basis in different Mongolian aimags over a
ten-year period. In order to carry out in-depth research, we used the
submeridional and sublatitudinal principles for selecting the model study
areas, as well as specific criteria and expert assessment. We used a
sociological survey as the main method, based on a designed questionnaire,
which was translated into Mongolian. The questionnaire includes questions
regarding the influence of desertification on traditional nomadic farming,
health of family members, water supply of households, water quality, living
standards, etc. The results of the sociological surveys made it possible to
draw conclusions on the impact of desertification on households, to identify
the main problems of local people, and to describe the dynamics of the
socio-economic status of the population living in the model areas. Our
studies have demonstrated the intensification of the impact of
desertification processes in different natural zones,
administrative-territorial units and settlement systems in Mongolia.
Tsybekmitova, G.T. Phytocenosis biodiversity at various water levels in mesotrophic Lake Arakhley, Lake Baikal basin, Russia / G.T. Tsybekmitova, L.D. Radnaeva, N.A. Tashlykova, V.G. Shiretorova, B.B. Bazarova, A.K. Tulokhonov, M.O. Matveeva // PeerJ. – 2021. –9:e11628. https://doi.org/10.7717/peerj.11628. (JCR IF – 2.98, Q2). https://peerj.com/articles/11628/
Small lakes have lower
water levels during dry years as was the case in 2000–2020. We sought to
show the biodiversity of plant communities at various water levels in Lake
Arakhley. Changes in moisture content are reflected in the cyclical
variations of the water level in the lake, which decreased approximately 2 m
in 2017–2018. These variations affect the biological diversity of the
aquatic ecosystems. We present the latest data on the state of the plant
communities in this mesotrophic lake located in the drainage basin of Lake
Baikal. Lake Arakhley is a freshwater lake with low mineral content and
a sodium hydrocarbonate chemical composition. Changes in the nutrient
concentration were related to precipitation; inflow volume and organic matter
were autochtonous at low water levels. The most diverse groups of
phytoplankton found in the lake were Bacillariophyta, Chlorophyta, and
Chrysophyta. High biodiversity values indicate the complexity and
richness of the lake’s phytoplankton community. A prevalence of Lindavia
comta was observed when water levels were low and Asterionella
formosa dominated in high-water years. The maximum growth depth of
lacustrine vegetation decreased from 11.0 m to 4.0 m from 1967 to
2018. Decreasing water levels were accompanied by a reduction in the
littoral zone, altering the communities of aquatic plants. The
hydrophyte communities were monodominant in the dry years and were
represented by Ceratophyllum demersum. The vegetation cover of the lake
was more diverse in high-water years and variations in the lake’s water
content altered the composition of biogenic substances. These changes
were reflected in the lake’s phytocenosis.
Sha, Lou. Laboratory study of the efects of fexible
vegetation on solute difusion in unidirectional fow / Sha Lou, Hao Wang, Hongzhe
Dorzhievna Radnaeva, Elena
Liu // Environmental Sciences Europe. – 2021. – Vol. 33. 80.
https://doi.org/10.1186/s12302-021-00521-y. (JCR IF – 5.893, Q1). https://enveurope.springeropen.com/articles/10.1186/s12302-021-00521-y
Flexible vegetation is an
important part of the riverine ecosystem, which can reduce flow velocity,
change turbulence structure, and affect the processes of solute
transport. Compared with the flow with rigid vegetation, which has been
reported in many previous studies, bending of flexible vegetation increases
the complexity of the flow–vegetation–solute interactions. In this
study, laboratory experiments are carried out to investigate the influence of
flexible vegetation on solute transport, and methods for estimating the
lateral and longitudinal diffusion coefficients in the rigid vegetated flow
are examined for their applications to the flow with flexible vegetation. The
methods proposed in this study can be used to estimate the lateral and
longitudinal diffusion coefficients in flows through both rigid and flexible
vegetations using the effective submerged vegetation height.
Bazarsadueva, S.V. The
Comparison of Fatty Acid Composition and Lipid Quality Indices of Roach,
Perch, and Pike of Lake Gusinoe (Western Transbaikalia) / S.V. Bazarsadueva,
L.D. Radnaeva, V.G. Shiretorova, E.P. Dylenova // International Journal of
Environmental Research and Public Health. – 2021. – 18. – 9032. https://doi.org/10.3390/ijerph18179032. (JCR IF – 3.390; Q1).
This paper describes the
study of the fatty acid (FA) composition of three fish species (roach, perch,
and pike) from Lake Gusinoe (western Transbaikalia). Using principal
component analysis, the fatty acid composition of the studied fish species
was shown to be species specific. The muscle tissue of roach, perch, and pike
was found to contain high levels of polyunsaturated fatty acids (PUFA),
including essential docosahexaenoic (DHA), eicosapentaenoic (EPA), and
arachidonic acids. Indicators of nutritional quality based on the fatty acid
composition showed that the values of the
hypocholesterolemic/hypercholesterolemic (HH) ratio indices were sufficiently
high. The atherogenicity (AI) and thrombogenicity (TI) indices, which are
indicators for the nutritional value, were less than 1 in the studied fish.
In terms of flesh lipid quality (FLQ), pike and perch had the highest
proportion of total EPA + DHA. According to the obtained data for the
composition of fatty acids in the muscle tissue of the studied fish from Lake
Gusinoe, the anthropogenic load exerted on Lake Gusinoe has not yet
statistically significantly affected the fish muscle quality.
Potassium and thallium conductors with a
trigonal structure in the M2MoO4–Cr2(MoO4)3–Hf(MoO4)2 (M = K, Tl) systems:
Synthesis, structure, and ionic conductivity / V.G. Grossman, M.S. Molokeev,
B.G. Bazarov, J.G. Bazarova // Journal of Alloys and Compounds. – 2021. – V.
873. – P. 159828. https://doi.org/10.1016/j.jallcom.2021.159828
- 4.650, Q1)
The triple molybdates M5CrHf(MoO4)6 (M = K, Tl) and TlCrHf0.5(MoO4)3 were found upon studying the
corresponding ternary molybdate systems M2MoO4–Cr2(MoO4)3–Hf(MoO4)2 (M = K, Tl) in the subsolidus region
using X-ray powder diffraction. The crystal structures ofM5CrHf(MoO4)6 (M = K, Tl) and TlCrHf0.5(MoO4)3 are refined by Rietveld method. M5CrHf(MoO4)6 (M = K, Tl) crystallizes in space group R3¯c with unit cell parameters: a = b = 10.45548
(5), c = 37.24614 (3) Å, V = 3526.14 (4) Å3, Z = 6 for K5CrHf(MoO4)6 and a = b = 10.53406
(12), c = 37.6837 (5) Å, V= 3621.39 (9) Å3, Z = 6 for Tl5CrHf(MoO4)6.
TlCrHf0.5(MoO4)3crystallizes in space group R3¯ with unit cell parameters: a = b= 12.9710 (2), c = 11.7825 (2) Å, V = 1716.78 (6) Å3, Z = 6. The thermal
stability and electrical conductivity of the new compounds were investigated.
Electrical conductivity measurements gave high values for the triple
molybdatesM5CrHf(MoO4)6 (M = K, Tl) (σ = 5.22 × 10−4 S / cm for K5CrHf(MoO4)6, σ = 1.1 × 10−2 S / cm for Tl5CrHf(MoO4)6 at 773 K) and relatively
low values for the triple molybdate TlCrHf0.5(MoO4)3 (σ = 4.42 × 10−6 S
/ cm at 773 K).
crystal growth and properties of novel magnetic double molybdate RbFe5(MoO4)7
with mixed Fe3+/Fe2+ states and 1D negative thermal expansion† / O. D.
Chimitova, B. G. Bazarov, J. G.
Bazarova, V. V. Atuchin, R. Azmi, A. E. Sarapulova, D. Mikhailova, G.
Balachandran, A. Fiedler, U. Geckle, Yu. Prots, A. C. Komarek, T. A. Gavrilova,
I. P. Prosvirin, Yi Yang, Zheshuai Lin, M. Knappd and H. Ehrenberg //
CrystEngComm. – 2021. – V. 23. – P. 3297–3307. DOI:
https://doi.org/10.1039/D1CE00118C (IF JCR - 3.117,
Single crystals of new compound RbFe5(MoO4)7 were successfully grown by the flux
method, and their crystal structure was determined using the X-ray
single-crystal diffraction technique. The XRD analysis showed that the
compound crystallizes in the monoclinic space group P21/m, with unit cell parameters a = 6.8987(4), b = 21.2912(12) and c = 8.6833(5) Å, β =
102.1896(18)°, V = 1246.66(12) Å3, Z (molecule number in the unit cell) =
(reliability factor) = 0.0166, and T = 293(2) K. Raman spectra were
collected on the single crystal to show the local symmetry of MoO4 tetrahedra, after the confirmation
of crystal composition using energy dispersive X-ray spectroscopy (EDS). The
polycrystalline samples were synthesized by a solid-state reaction in the Ar
atmosphere; the particle size and thermal stability were investigated by
scanning electron microscopy (SEM) and differential scanning calorimetry
(DSC) analyses. The compound decomposes above 1073 K in an Ar atmosphere with
the formation of Fe(III) molybdate. The thermal expansion coefficient along
the c direction has the value α = −1.3
ppm K−1 over the
temperature range of 298–473 K. Magnetic measurements revealed two maxima in
the magnetization below 20 K, and paramagnetic behavior above 50 K with the
calculated paramagnetic moment of 12.7 μB per formula unit is in
good agreement with the presence of 3Fe3+ and 2Fe2+ in the high-spin (HS) state. The
electronic structure of RbFe5(MoO4)7 is comparatively evaluated using
X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT)
Exploration of structural, thermal and
vibrational properties of new noncentrosymmetric double borate Rb3Tm2B3O9 / Subanakov
A.K., Kovtunets E.V., Bazarov B.G., Pugachev A.M., Sofich D.O., Bazarova,
J.G. // Solid state sciences. – 2021. – V. 120. – N. 106719..2021.106719. Doi:
10.1016/j.solidstatesciences (IF JCR -
Double borate Rb3Tm2B3O9 was
newly synthesized by solid-state reaction. The crystal structure of Rb3Tm2B3O9 was
refined by Rietveld's method: Pna21, a = 8.6648(1),b = 9.5238(1), c = 12.1722(1)
Å, Z = 4. The crystal structure of Rb3Tm2B3O9 consists
of -[Tm2O9]∞- chains along the “a” axis. BO3 triangles
linked chains in a three-dimensional framework. Rubidium atoms occupied empty ones
in channels. The thermal behavior of Rb3Tm2B3O9 was
studied in detail in between 25 and 1200 °C by DSC and TG methods. Rb3Tm2B3O9 was
congruently melted at 886 °C.
The band gap is found as Eg ∼5.14 eV. Nonlinear optical response of Rb3Tm2B3O9 tested
via SHG is estimated to be lower than that of KDP. The existence of BO3 groups
in Rb3Tm2B3O9crystal structure
has been confirmed by an IR analysis.
Na9In(MoO4)6: synthesis, crystal structure and Na+ ion diffusion/
Buzlukov A.L., Arapova I.Yu., Baklanova Ya.V., Savina A.A., Morozov V.A., Bardet M., Lazoryak B.I., Khaikina E.G., Denisova T.A., Medvedeva N.I. // Ionics.
2021. Vol. 27, № 10. P. 4281–4293. DOI: 10.1007/s11581-021-04226-3 (IF JCR - 2.817, Q2)
Fundamental studies of the materials with fast sodium mobility are
important for the development of energy storage systems. This article
presents the results of experimental studies of Na-conducting oxide Na9In(MoO4)6.
This compound crystallizes in rhombohedral symmetry with the space group R 3¯¯¯3¯ c and the unit cell parameters: a = 15.08695(6) and c = 19.1701(2) Å.
Impedance spectroscopy measurements show that Na9In(MoO4)6 is an ionic conductor with a
conductivity of about 2.1 × 10−2 Sm·cm−1 at 803 K. The 23Na NMR data reveal the
coexistence of three types of sodium motion. These
motional processes are activated at different temperatures and are
characterized by substantially different nature and dynamics characteristics.
Concretes made of magnesium-silicate rocks /
L.I. Khudyakova, E.V. Kislov, I.Y. Kotova, P.L. Paleev // Minerals. – 2021. –
V. 11. – Р. 441–457. https://doi.org/10.3390/min11050441 (IF JCR - 2.380, Q2)
present, there is a shortage of high-quality feedstock to produce widely used
building materials-concretes. Depletion of natural resources and growing
restrictions on their extraction, in connection with environmental
protection, necessitate the search for an equivalent replacement for
conventional raw materials. Magnesium-silicate rocks are a waste of the
mining industry. We researched the possibility of using these rocks as coarse
and fine aggregates in heavy concrete production. Following the requirements
of the national standards, we studied the physical and mechanical
characteristics of the obtained material. It was found that the strength of
concrete, made of magnesium-silicate rock coarse aggregate, at the age of 28
days of hardening is within 28 MPa, while the strength of the control sample
is 27.3 MPa. Replacing quartz sand with dunite sand also leads to an increase
in concrete strength (similar to 4%). Complete replacement of aggregates
facilitates an increase in strength by 15-20% than the control sample. At the
same time, the density of the obtained materials becomes higher. Concretes
have a dense structure that affects their quality. Concrete water absorption
is within 6%. The fluxing coefficient is 0.85-0.87. The application of
magnesium-silicate rocks in concrete production enables the complete
replacement of conventional aggregates with mining waste without reducing the
quality of the obtained materials. Furthermore, the issues of environmental
protection in mineral deposit development are being addressed.
Farion I.A., Burdukovskii
V.F., Kholkhoev B.Ch., Timashev P.S. Unsaturated and thiolated derivatives of
polysaccharides as functional matrixes for tissue engineering and
pharmacology: A review // Carbohydrate Polymers. – 2021. – V.259. – 117735.
Doi: 10.1016/j.carbpol.2021.117735 (IF JCR - 9.381, Q1).
This review examines investigations into
the functionalization of polysaccharides by substituents containing multiple
(C=C) bonds and thiol (SH) groups that are prone to (co)polymerization in the
presence of thermal, redox and photoinitiators or Michael addition reactions.
A comparative analysis of the approaches to grafting the mentioned
substituents onto the polysaccharide macromolecules was conducted. The use of
the modified polysaccharides for the design of the 3D structures, including
for the development of the pore bearing matrixes of cells or scaffolds
utilized in regenerative medicine was examined. These modified polymers were
also examined toward the design of excipient matrixes in pharmacological
compositions, including with controllable release of active pharmaceuticals,
as wel as of antibacterial and antifungal agents and others. In addition, a
few examples of the use of modified derivatives in other areas are given.
Bardakova K.N., Kholkhoev
B.Ch., Farion I.A., Epifanov E.O., Korkunova O.S., Efremov Y.M., Minaev N.V.,
Solovieva A.B., Timashev P.S., Burdukovskii V.F. 4D printing of shape-memory
semi-interpenetrating polymer networks based on aromatic heterochain polymers
// Advanced Materials Technologies. – 2021. (Early Access).
DOI 10.1002/admt.202100790 (IF
JCR - 7.848, Q1).
Most of the presently known
thermosensitive shape-memory polymers suitable for 4D printing have
insufficient mechanical strength and thermal stability that restricts their
potential areas of application. Here, new photosensitive compositions (PSCs)
based on aromatic heterochain polymers –
poly-N,N′-(m-phenylene)isophthalamide (MPA) or
poly-2,2′-(p-oxydiphenylene)-5,5′-dibenzimidazole (OPBI) – for DLP printing
are proposed. Thermal post-curing and supercritical carbon dioxide (scCO2)
are used for post-processing of the structures. During the scCO2 treatment
the removal of unreacted monomeric component (N,N-dimethylacrylamide) and its
uncrosslinked oligomers is accompanied by the preservation of the initial
degree of crosslinking. The more stable shrinkage is observed for the
combined post-processing method (T°+scCO2) in the case of OPBI-PSC and after
the heat treatment for MPA-PSC specimens. The method of post-processing and
the nature of the heterochain polymer strongly affect the mechanical
properties and thermal resistance of the structures. The tensile strength has
the maximum value after the thermal post-treatment (101.1 ± 7.1 and 78.4 ±
5.1 MPa of OPBI-PSC and MPA-PSC, respectively). The intense destruction of
the materials is observed at 393 and 408 °C for MPA-PSC and OPBI-PSC,
respectively. Moreover, the 4D-printed structures exhibit excellent shape
memory performance at transition temperatures >100 °C, thus have a great
potential for the use in aerospace, robotics, sensorics.
S.A. Stelmakh, M.N. Grigor’eva, N.M. Garkusheva, S.N.
Lebedeva, O.S. Ochirov, D.M. Mognonov, S.D. Zhamsaranova, V.B. Batoev. Studies
of new biocidal polyguanidines: antibacterial action and toxicity. Polymer bulletin, V78, №4. 2021, P. 1997-2008. Doi 10.1007/s00289-020-03197-1
(IF= 2.870, Q2)
The aim of this
study was to obtain new water-soluble polyguanidines, assess their antimicrobial
properties with respect to the test objects of Escherichia coli and Bacillus
cereus and establish the hazard class regulated in the territory of
the Russian Federation. Polymers obtained in high yields by the method of
polycondensation in the melt of the corresponding monomers and characterized
by the methods of IR spectroscopy and elemental analysis. Serial
dilution–agar plate procedure was performed in order to estimate
antibacterial effects. The biocidal properties of the samples were estimated
by the percentage reduction of microorganisms (% reduction). To determine the
acute toxicity, a toxicometric assessment and symptoms of intoxication upon
oral administration of a single dose were carried out in laboratory animals.
New water-soluble guanidine-containing polymers with a number average
molecular weight of 660–1040 Da were obtained. Copolymers with a low
degree of substitution (10–20%) exhibit high antimicrobial activity
among N-phenyl-substituted samples. As a result of the
substituent increase in the polymer chain, their activity in relation to the
studied bacteria is linearly decreased to a level comparable to the test
sample. In contrast to the N-octyl-substituted copolymers,
gram-positive bacterium B. cereus is more susceptible
to N-phenyl-substituted samples. Substances after intragastric
injection belong to the fourth class of toxicity (LD50 > 300 ≤ 2000 mg/kg)
according to the requirements of tabulation of toxicity classes regulated in
the territory of the Russian Federation. The combination of low toxicity with
a high level of antibacterial activity of new guanidine-containing polymers
suggests the possibility of obtaining new effective disinfectants.
Degradation of Bisphenol A in Aqueous Solution by Photo-Fenton-like
Process Using UV KrCl Excilamp / D.
Aseev, A. Batoeva, М. Sizykh, D.
Olennikov, G. Matafonova // Int. J. Environ. Res. Public Health, 2021, 18, 1152. https://doi.org/10.3390/ijerph18031152 (IF JCR - 3.39, Q1).
A (BPA), a precursor to important plastics, is regarded as a common aquatic
micropollutant with endocrine-disrupting activity. In the present study, we
explored the capability of a UV KrCl excilamp (222 nm) to degrade BPA by a
photo-Fenton-like process using persulfate under flow-through conditions. The
first-order rate constants of degradation were obtained and the
mineralization of dissolved organic carbon (DOC) was estimated. The results
showed complete BPA degradation and high DOC mineralization (70–97%). A
comparative analysis of degradation rates and DOC removal in the examined
systems (UV, Fe2+/S2O82−, UV/S2O82− and
UV/Fe2+/S2O82−) revealed a
significant synergistic effect in the photo-Fenton-like system (UV/Fe2+/S2O82−)
without the accumulation of toxic intermediates. This indicated that the BPA
was oxidized via the conjugated radical chain mechanism, which was based on
the photo-induced and catalytic processes involving HO• and
SO4−• radicals. The primary intermediates of BPA
degradation in the UV/Fe2+/S2O82− system
were identified by HPLC/MS and the oxidation pathway was proposed. The high
performance of the photo-Fenton-like process employing a quasi-monochromatic
UV radiation of a KrCl excilamp offers promising potential for an efficient removal
of such micropollutants from aqueous media.
Budaev S.L., Batoeva A.A., Tsybikova B.A.,
Khandarkhaeva M.S., Aseev D.G. Photochemical degradation of thiocyanate by
sulfate radical-based advanced oxidation process using UVС KrCl-excilamp //
J. Environ. Chem. Eng., 2021, 9 (4), 105584. https://doi.org/10.1016/j.jece.2021.105584
(IF - 5.909, Q1)
The degradation of
thiocyanates (SCN−) by UV-C-activated persulfate (PS) in the
presence of ferric ion (Fe3+) was investigated. As a source of
monochromatic far-UV-C irradiation (222 nm), mercury-free KrCl excimer lamp
was used. Results showed that compared with direct photolysis, UVC/ PS and
PS/ Fe3+, the combined UVC/ PS/ Fe3+ treatment had
the highest initial reaction rate ω0 and removal
efficiency. 99.99% conversion of thiocyanates (100 mg/L of initial
concentration) was achieved in 40 min. The addition of Fe3+ in
the UVC/ PS treatment was found to reduce energy consumption (calculated as
amount of oxidized thiocyanates per consumed electrical energy) by 4.5 times,
while only a 30% difference between direct photolysis and UVC/ PS was
observed. The high efficiency of the UVC/ PS/ Fe3+ process
revealed a synergistic effect (synergy index ƒ = 1.98).
The effect of the initial SCN−, PS, and Fe3+ molar
ratios and UV-C exposure time on SCN− removal in UVC/ PS/ Fe3+ was
further investigated. It was found that at molar ratios [S2O82–]:[SCN−]
= 3:1 and [S2O82–]:[Fe3+] = 1:0.1,
effective decomposition of SCN− in a wide initial concentration
range (from 50 to 500 mg/L or 0.86–8.6 mM) can be achieved. The
strong role of •OH and SO4•− in
the removal of SCN− was confirmed by the addition of radical
scavengers. It was demonstrated that the presence of Cu2+ in
simulated gold mine wastewater effluents neutralizes the inhibitory effects
that S2O32– and NH4+ have
on the degradation process.
S., Tsenter I., Garkusheva N., Beck S.E., Matafonova G., Batoev V. Evaluating (sono)-photo-Fenton-like processes
with high-frequency ultrasound and UVA LEDs for degradation of organic
micropollutants and inactivation of bacteria separately and simultaneously //
J. Environ. Chem. Eng. – 2021. – V. 9. – 105249. https://doi.org/10.1016/j.jece.2021.105249
(IF JCR - 5.909, Q1)
This study reports the
performance of high-frequency ultrasound (US, 1.7 MHz), coupled
with a photo-Fenton-like process using persulfate and UV LEDs (UV/PS/Fe2+),
for eliminating organic micropollutants and bacteria separately and
simultaneously in deionized and natural water. Water matrices, containing
atrazine (ATZ)/bisphenol A (BPA)) and Escherichia
were sequentially treated by UV/PS/Fe2+ and UV/US/PS/Fe2+ processes.
The highest degradation rates by UV/US/PS/Fe2+ process were found
for BPA in both matrices, achieving complete removal and synergistic effects
(φ>1). In terms of inactivation, this process was most efficient in
deionized water for reducing E. coli
and E. faecalis by 3 and 5 logs,
respectively. The addition of bacteria inhibited the degradation in both matrices by
decreasing the pseudo first-order rate constants up to one order of
magnitude. In turn, the addition of micropollutants delayed the inactivation
to various extents only in deionized water. In natural water, the
co-existence of micropollutants accelerated the inactivation of E. coli, reaching 100% in 5 min
with BPA and 7 min with ATZ (vs. 10
min without ATZ or BPA). The more resistant E. faecalis showed similar inactivation kinetics regardless of the added compound. Induction
of oxidative stress in cells by micropollutants and higher exposure to additional ROS via (sono)photosensitization reactions
are suggested as responsible for enhancing inactivation in natural water. The
UV doses required for 90% degradation in the presence of bacteria (2.6-7.7 J/cm2)
provide the simultaneous inactivation. Results show that the
sono-photo-Fenton-like process could be a promising alternative for
simultaneous water treatment and disinfection.
Matafonova G., Batoev V. Dual-wavelength light
radiation for synergistic water disinfection // Sci. Tot. Environ. – 2021. - https://doi.org/10.1016/j.scitotenv.2021.151233
(IF JCR - 7.963,
Development of the narrow-band
mercury-free light sources, such as light emitting diodes (LEDs) and
excilamps, has stimulated research on inactivation of pathogenic
microorganisms by dual-wavelength light radiation. To date, dual-wavelength
light radiation has emerged as an advanced tool for enhancing microbial
inactivation in water in view of potential synergistic effect. This is the
first review that aims at elucidating its mechanisms under dual-wavelength
light exposure and surveying a body of related literature in terms of
yes-or-no synergy. We have proposed three key inactivation mechanisms, which
function in the estimated spectrum ranges I (190-254 nm), II (250-320 nm)
and III (300-405 nm) and provide a synergistic effect when combined. These
mechanisms involve proteins damage and DNA repair suppression
(I), direct and indirect DNA damage (II) and generation of reactive oxygen
species (ROS) by endogenous photosensitizers (III), such as porphyrins and
flavins. A synergy under dual-wavelength light irradiation
simultaneously or sequentially occurs if coupling two wavelengths of different ranges (I
+ II, I + III, II + III) in order to trigger different inactivation
mechanisms. Recent advances of dual-wavelength light strategy in
photodynamic therapy could be applied for water disinfection. They bring
opportunities for applying the sources of near-UV and visible radiation and
making the disinfection processes more energy- and cost-effective. From this
standpoint, the synergistically efficient dual-wavelength combinations II +
III and the combinations within the extended to 700 nm range III (near-UV +
VIS) appear to be promising for developing novel advanced oxidation processes
for disinfection of real turbid waters.
Maksanova, L., Bardakhanova, T., Lubsanova, N., Budaeva, D., &
Tulokhonov, A. (2021). Assessment of losses to the local population due to
restrictions on their ownership rights to land and property assets: The case
of the Tunkinsky National Park, Russia. Plos one, 16(5), e0251383. DOI:10.1371/journal.pone.0251383. (IF JCR - 3.240, Q2)
The impact of protected areas on
local communities is the subject of intense discussions as part of the
implementation of the global ecosystem protection agenda. Conflicts between
the interests of environmental protection and the needs of socio-economic
development become particularly acute when large areas of land are taken out
of economic circulation as a result of organizing protected areas. In this
case, there is an urgent need for detailed and reliable information about the
social impacts of such land withdrawal on the well-being of the local
population. An analysis of the methodological approaches widely presented in
the literature, used to assess the social impact of protected areas,
testifies to the insufficiency of completed and practically applicable
methodological guidelines for the areas with significant restrictions for
people who form part of the protected landscape. In this study, we understand
the cost estimate of the social impact of national parks on the local
population as a quantitative calculation of the losses due to restrictions on
their ownership rights to land and property assets. The methodological
approach consists in considering the category of losses as a sum total of the
actual damage and lost profits. The assessment algorithm includes three
stages: systematization of social impacts on citizens, development of
indicators and data collection, and calculation of actual damage to the
population and lost profits. The assessment is performed using the example of
the Tunkinsky National Park located in the Tunkinsky municipal district of
the Republic of Buryatia, a region of the Russian Federation, where there are
14 rural settlements with a population of more than 20,000 people. The
results of the calculations show that the losses of the rural population due
to legal restrictions on the registration of land dealings amount to 170.4
million USD. Taking into account the potential amount of administrative fines
and the value of property subject to demolition, the losses amount to 239.2
million USD. It is more than an order of magnitude greater than the amount of
own revenues of the Tunkinsky municipal district in 2011-2019. The results
obtained demonstrate the real picture of the impact of restrictions on the
rights of local people to land within the boundaries of national parks and
are useful for developing measures to account for their interests and include
protected areas in the socio-economic development of regions. The
methodological approach developed by the authors can be used in other
national parks, where it is necessary to optimize the policy of improving
land use for local residents.
Bilgaev, A., Dong, S., Li, F., Cheng, H., Tulohonov,
A., Sadykova, E., & Mikheeva, A. (2021). Baikal Region (Russia)
Development Prospects Based on the Green Economy Principles. Sustainability,
13(1), 157. DOI:10.3390/su13010157. (IF JCR - 3.251, Q2)
The problems of preserving the natural environment
are relevant for unique natural complexes of territories, such as the Baikal
region (Russia). There are few studies devoted to forecasting the green
economic development of the eco-socio-economic system of the Baikal region.
The previous studies are mainly dedicated to the theory of forming the green
economy in the Baikal region. This study aimed to forecast and determine
future trends in the Baikal region’s eco-socio-economic development based on
the green economy. The methodological approach to assess the Baikal region
development prospects is based on determining the factors affecting the
relationship between various eco-socio-economic components using multiple
regression models. We constructed the forecast using the artificial neural
networks method, and we assessed the possible impact of anthropogenic factors
on the Baikal region’s eco-socio-economic system in the future. Based on the
obtained forecast, we proposed a mechanism for regulating the green economy
formation in the region. The regional governments of the Baikal region should
perform the management function. This requires establishing a special interregional
Green Development Fund to restructure incoming public funds by redistributing
financial flows from contaminating brown to green industries and develop a
state program for the Green Development of the Baikal region. The constructed
forecast is informational support for decision making for the long-term
development of the economy during the transition to the green economy, the
development and justification of program activities, and the future’s main
Bilgaev, A., Sadykova, E., Li, F., Mikheeva, A.,
& Dong, S. (2021). Socio-Economic Factor Impact on the Republic of
Buryatia (Russia) Green Economic Development Transition. International
Journal of Environmental Research and Public Health, 18(20), 10984. DOI:10.3390/ijerph182010984 (IF JCR - 3.390, Q1)
Sustainable green development and
environment preservation problems are relevant for unique territories with
special economic activity modes, such as the Baikal natural territory. Within
Russia, the Republic of Buryatia serves as the model territory for the Lake
Baikal ecosystem preservation. Determining the socio-economic development
impact on the region’s natural environment and resolving contradictions in
transition to the green economic development requires the systematization of
economic, social, and environmental processes of quantitative information
based on the construction of composite indicators. We construct a composite
indicator to assess the socio-economic factor’s impact on the Republic of
Buryatia’s current economic state and to compare the current environmental
subsystem state and the socio-economic parameters of Buryatia to the average
Russian level. We use multiple regression models to determine relationships
between various environmental-socio-economic parameters and identify the
factors that most impact the environmental states (situations). The measures
taken to preserve the unique ecosystem of Lake Baikal have an actual effect.
This study shows, that according to the accepted scale, the environmental
situation in the region can be characterized as a step towards the green
economy transition. The proposed sustainable green development criteria and
tools assessment system of the Republic may serve as the basis for forming
information and analytical support for an effective economic policy.
Prishchepov AV, Ponkina EV, Sun ZL, Bavorova M,
Yekimovskaja OA. 2021. Revealing the intentions of farmers to recultivate
abandoned farmland: A case study of the Buryat Republic in Russia // LAND USE
POLICY, 2021.- 107: 105513. Doi: 10.1016/j.landusepol.2021.105513 (IF JCR – 5.398,
Despite the looming land scarcity
suited for agricultural expansion, farmland abandonment is widespread
globally. The recultivation of some abandoned farmlands could unlock the
untapped agricultural potential. Yet, little is known about the determinants of
recultivation. To better understand the behavioral intentions of farmers
regarding the recultivation of abandoned lands, we concentrated on the Buryat
Republic in Russia, where agricultural land abandonment is widespread and
farmers with different ethnicities carry out diverse agricultural practices.
We conducted 149 face-to-face interviews with the farmers in the Buryat
Republic in 2018 and filled a structured questionnaire on farm's and farmers'
socioeconomic characteristics, perceived corruption, and farmers' behavioral
intentions regarding expected land use. We modeled the intention of
recultivation with the Bayesian networks. The Bayesian networks analysis
showed that perceived corruption was considered to be a barrier to
recultivation. Our study also showed that non-Buryat ethnic and young farmers
are more likely to recultivate abandoned land. Abandoned farmlands without or
with a low degree of afforestation were preferred for recultivation. In sum,
our study showed how behavioral aspects of political trust, the farm's and
farmer's characteristics, in combination with regional and locational
characteristics, may shape farmers' decisions on land use. The results
provide an important ground to assess regional land-use policies, which
should foster the recultivation of abandoned lands while preserving ecosystem
services in the global hotspots of farmland abandonment, such as Russia