bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperature investigations of magnetic properties when analyzing the structural phase state of a model nanocomposite with carbidosteel composition
Authors: Ulyanov A. I.  , Chulkina A. A.  , Ulyanov A. L.
Published: January 2023

The phase composition, magnetic state of the phases and their influence on the formation of the magnetic hysteresis properties of the nanocomposite with the (Fe0.85Mn0.10Ni0.05)83C17 composition after mechanosynthesis and subsequent annealing have been studied. It is shown that, although the dependences of the coercive force on the annealing temperature H_c(Tann) of the alloy, measured at room and liquid nitrogen temperatures, are curves with maxima, the formation of Hc is driven by different mechanisms. At room temperature measurements, the maximum Hc value of the composite is obtained when the size of the ferrite phase precipitates approaches to the critical single-domain state, whereas at low temperature maximum Hc value is caused by the change of the cementite structural state upon annealing. Keywords: Nanocrystalline Fe-C-Mn-Ni alloys, mechanical alloying, heat treatment, X-Ray diffraction, coercive force, magnetic susceptibility, Curie temperature, Mossbauer spectroscopy.
Delamination of multilayer graphene nanoribbons on flat substrates
Authors: Savin A. V.  , Klinov A. P.
Published: January 2023

Using molecular dynamics simulation, we have shown that multilayer graphene nanoribbons located on the flat surface of the h-BN crystal (on the flat substrate) delaminate due to thermal activation into a parquet of single-layer nanoribbons on the substrate. The delamination of graphene nanoribbons requires overcoming the energy barrier associated with the initial shift of its upper layer. After overcoming the barrier, the delamination proceeds spontaneously with the release of energy. The value of this barrier has been estimated and the delamination of two-layer nanofilms has been simulated. The existence of two delamination scenarios has been shown. The first scenario is the longitudinal (along the long side of the nanoribbon) sliding of the upper layer. The second one is in the sliding of the upper layer with the rotation of the layers relative to each other. The first scenario is common for elongated nanoribbons, the second --- for two-layer graphene flakes having close to a square shape. Keywords: graphene, multilayer nanoribbons, flat substrate, nanoribbon delamination.
Synthesis, crystal structure and high-temperature heat capacity of substituted apatites Pb-=SUB=-9-=/SUB=-R(GeO-=SUB=-4-=/SUB=-)-=SUB=-3-=/SUB=-(VO-=SUB=-4-=/SUB=-)-=SUB=-3-=/SUB=- (R=Tb, Dy, Ho)
Authors: Denisova L. T.  , Molokeev M. S.  , Golubeva E. O.  , Belousova N. V.  , Denisjv V. M.
Published: January 2023

Pb9R(GeO4)3(VO4)3 (R=Tb, Dy, Ho) apatites were obtained by solid-phase synthesis from the initial oxides of PbO, Tb2O3 (Dy2O3, Ho2O3), GeO2 and V2O5 by sequential annealing (at a temperature of 773-1073 K) in an air atmosphere. Their crystal structure has been determined by X-ray diffraction analysis. The high-temperature heat capacity was measured by differential scanning calorimetry. Based on the experimental dependence of the heat capacity on the temperature, the thermodynamic properties are calculated. Keywords: apatites, solid-phase synthesis, crystal structure, heat capacity, thermodynamic properties. Keywords: apatites, solid-phase synthesis, crystal structure, heat capacity, thermodynamic properties.
Triexcitons and their effect on absorption in the exciton region of the spectrum
Authors: Nad'kin L. Yu.  , Korovai O. V.  , Markov D. A.
Published: January 2023

The effect of the triexciton state on the absorption of exciton-polaritons is studied under conditions when two high-power laser radiation pulses interacting with biexcitons and triexcitons and a probe pulse at the frequency of the exciton transition are incident on the medium. It is shown that even at low triexciton binding energies under the action of two high-power pulses, the exciton state splits into three quasi-levels, and the Autler--Townes effect (optical Stark effect) is observed. It turned out that the position of the quasi-levels depends on the detuning of the resonance of the pump pulses and their intensities, which makes it possible to identify them. These circumstances make it possible to diagnose the triexciton state in semiconductors with a higher degree of probability not by studying the absorption spectral line of the biexciton--triexciton transition, but by the effect of the triexciton state on absorption in the region of the exciton transition. Keywords: excitons, biexcitons, triexcitons, Autler--Townes effect.
Electrical and Optical Characteristics of CsPbI-=SUB=-3-=/SUB=- and CsPbBr-=SUB=-3-=/SUB=- Lead Halide Perovskite Nanocrystal Films Deposited on c-Si Solar Cells for Photovoltaic Applications
Authors: Boudjemila L.  , Aleshin A. N.  , Malyshkin V. M.  , Aleshin P. A.  , Shcherbakov I. P.  , Petrov V. N.  , Terukov E. I.
Published: January 2023

The deposition of an additional layer of nanoparticles is a widely used method for improving the optical and electrical characteristics of semiconductor solar cells (SCs). In this work, films of nanocrystals (NC) of inorganic perovskites of lead halides CsPbI3 and CsPbBr3 are deposited on the surface of a solar cell based on crystalline silicon (c-Si). It is shown that the optical properties of such NC films are in good agreement with the optical properties of c-Si. It has been found that the absorption coefficient of solar cells with NC layers of inorganic perovskites is much higher in the visible region of the spectrum, which increases the photocurrent generation in the SC in the range of 370-900 nm. A significant effect of surface roughness on the photoelectric properties of solar cells has been found. CsPbI3 NC films have a textured surface and higher photocurrent than CsPbBr3 NC films, which are rougher. Enhanced photovoltaic properties of photoelectric structures with a CsPbI3 NC layer compared to CsPbBr3 NC films due to their lower degree of roughness were observed. Keywords: perovskite nanocrystals, silicon solar cells, reflection spectra, photoluminescence, electrical conductivity.
Ab initio studies of the effect of pressure on the structure, electronic and elastic properties of carbonates of alkali-alkaline earth metals
Authors: Zhuravlev Yu. N.
Published: January 2023

Density functional theory with a gradient PBE functional and dispersion correction D3(BJ) in the basis of localized orbitals of the CRYSTAL17 package was used to study the effect of pressure on the structural, electronic, and elastic properties of K2Ca(CO3)2, K2Mg(CO3)2, Na2Ca2(CO3)3, Na2Mg(CO3)2. The parameters of the third-order Birch--Murnaghan equation of state are determined, and it is shown that the equilibrium volume and compressibility modulus depend linearly on the average cation radius. Under pressure, the widths of the upper valence bands increase maximally in K2Ca(CO3)2 and minimally in Na2Ca2(CO3)3, while the centers of gravity of the cationic states shift by ~0.2 eV. Elastic constants and polycrystalline moduli are calculated, which increase with decreasing average cation radius. The shear modulus for K2Ca(CO3)2 and K2Mg(CO3)2 decreases with increasing pressure, and this leads to anomalous behavior of the longitudinal and transverse acoustic wave velocities. Keywords: ab initio calculations, buchliite, eithelite, shortite, equation of state, elastic moduli, density of states, pressure.
Synthesis, structural and magnetic properties of ludwigite Mn-=SUB=-1.32-=/SUB=-Ni-=SUB=-0.85-=/SUB=-Cu-=SUB=-0.83-=/SUB=-BO-=SUB=-5-=/SUB=-
Authors: Sofronova S. N.  , Eremin E.V.  , Moshkina E. M.  , Selyanina A. V.  , Bondarenko G. N.  , Shabanov A. V.
Published: January 2023

Single crystals of Mn1.32Ni0.85Cu0.83BO5 with the ludwigite structure were obtained by the solution-melt method during spontaneous crystallization. The concentration of copper, manganese and nickel ions was determined by transmission microscopy. Manganese ions are included in compounds in the divalent and trivalent states. The study of temperature and field dependences showed that we have several magnetic transitions. The first transition, associated with the ferrimagnetic ordering of the magnetic moments of parts of the ions, observed in the region of 50 K. In the region of 25 K, a second magnetic transition is observed. Substitution of nickel ions for copper and divalent manganese of better disorder and competition of exchange interactions, which leads to the division of the magnetic system into several magnetic subsystems that are ordered at different temperatures. Keywords: ludwigites, magnetic interface transition, indirect exchange interactions.
Radiation-stimulated phase transition to superionic state of the crystal TlSe
Authors: Sardarly R. M.  , Alieva N. A.  , Salmanov F. T.  , Gakhramanova S. M.  , Mehtieva R. N.  , Agaeva R. Sh.
Published: January 2023

The temperature-frequency dependences of: electrical conductivity (sigma(μ,T)), the real and imaginary parts of the complex permittivity (ε'(ν,T)) and (ε''(ν,T)), the complex impedance of the TlSe compound when exposed to various doses of gamma radiation. The process of the occurrence of concentration polarization at the boundary of the ion conductor blocking contact is investigated. The temperature-frequency-dose interval of the occurrence of ionic conductivity and the Warburg impedance has been established and a radiationally stimulated phase transition to the superionic state of the TlSe crystal has been detected. Keywords: complex impedance, blocking contact, of ionic conductivity.
Luminescent properties of solid solutions of yttrium-scandium phosphates doped with europium ions
Authors: Wozniak-Levushkina V. S.  , Arapova A. A.  , Spassky D. A.  , Nikiforov I. V.  , Zadneprovsky B. I.
Published: January 2023

The luminescent properties of solid solutions Y1-xScxPO4 : 0.5 mol.% Eu3+ (x=0,0.2, 0.4, 0.5, 0.6, 0.8, 1) under excitation by ultraviolet and vacuum-ultraviolet radiation were studied. The influence of disorder of the crystal structure in solid solutions on the structure of Eu3+ luminescence spectra is shown. A non-linear dependence of values of the optical band gap on solid solution composition was obtained and a model was suggested to explain this effect. Keywords: energy transfer, luminescence, solid solutions, ScPO4 : Eu3+, YPO4 : Eu3+.
Construction of an approximate solution for a dilute magnet based on the solution for a pure magnet on the same lattice
Authors: Semkin S. V.  , Smagin V. P.
Published: January 2023

The paper proposes a method for approximate calculation of the magnetization of a dilute Ising magnet on a certain lattice, based on the use of an exact or approximate solution for a pure Ising magnet on the same lattice. Using the proposed method, it is possible to calculate the dependence of magnetization on temperature and concentration of non-magnetic impurities and the Curie temperature as a function of concentration for a diluted magnet. The proposed method is applied in the work to the solution in the mean field approximation, to the solution in the beta approximation, and to the exact solution on a square lattice. Keywords: phase transitions, Ising model, dilute magnet.
Formation of natural composites from melts, calculations and control of parameters of aperiodic impurity profiles
Authors: Chevrychkina A.A.  , Korzhenevskii A.L.
Published: January 2023

The method for purposefully creating aperiodic radial impurity structures and controlling the shape of their spatial profiles in dilute alloys is presented. That is derived based on an analytical approach supported by the results of numerical calculations. Keywords: unsteady directional controlled solidification, mobile impurities, aperiodic impurity profiles.
Lattice dynamics and phase transitions in a crystal Ba-=SUB=-2-=/SUB=-ZnTeO-=SUB=-6-=/SUB=-
Authors: Zinenko V. I.  , Shinkorenko A. S.
Published: January 2023

The lattice dynamics of Ba2ZnTeO6 double perovskite in three phases has been studied. Vibrational spectra and dynamic charges are calculated. In the rhomobohedral phase R3m, soft modes were found; after their condensation, the C2/m phase was obtained, which agrees with the experiment. An assessment was made of the dependence of the enthalpy of different phases on pressure; it showed that the monoclinic phase is more favorable at 0 pressure, but as the pressure increases to 2.9 GPa, the cubic phase Fm3m becomes advantageous. Keywords: Lattice dynamics, phase transitions, double perovskites.
Quasi-local vibrations in amorphous solids in the framework of the theory of non-Gaussian random matrices
Authors: Conyuh D. A.  , Beltukov Y. M.
Published: January 2023

The statistical features of quasi-local vibrations of disordered systems are studied within the framework of the model of correlated random matrices. It is shown that the statistics of matrix elements of the dynamical matrix strongly affects the properties of such vibrations. The lowest frequency part of the density of states of quasilocal vibrations is described by the expression rhoqlv(ω) propto ωn, where the power n is the number of neighboring atoms. However, if the distribution of matrix elements is strongly non-Gaussian, an additional dependence rhoqlv(ω) propto ω^γ appears, where the power γ decreases as the degree of non-Gaussianity increases. Keywords: quasi-local vibrations, amorphous solids, random matrices.
Formation of phase states in PbFe-=SUB=-0.5-=/SUB=-Nb-=SUB=-0.5-=/SUB=-O-=SUB=-3-=/SUB=-: Description based on multiminima models
Authors: Ivliev M. P.  , Raevskaya S. I.  , Titov V. V.  , Raevski I. P.
Published: January 2023

Two ferroelectric phase transitions are observed in the PbFe0.5Nb0.5O3 crystal. The first is between the cubic and tetragonal phase, the second is between the tetragonal and monoclinic phases. To describe phase transitions and emerging phases, a statistical model is proposed, based on the composition of two multi-minimum models --- a six-minima model for the Pb cation and an eight-minima model for the Nb cation. Adjusting the model parameters, makes it possible to reproduce all the characteristic features of the thermodynamic behavior of the crystal. The most interesting is the formation of a ferroelectric, complexly ordered monoclinic phase with Cm symmetry. It is shown that the mentioned monoclinic phase arises due to the fact that the first-order phase transition to the rhombohedral ferroelectric phase occurs in the presence of an "external field" of tetragonal symmetry. The contribution of the subsystems of Pb and Nb cations to the features of the dielectric and structural properties of the crystal is estimated. Keywords: ferroelectric relaxors, phase transitions, multiminima models, ferroelectric monoclinic phase.
Magnetocaloric properties of a ribbon sample of Heusler alloy Ni-=SUB=-45-=/SUB=-Co-=SUB=-5-=/SUB=-Mn-=SUB=-31-=/SUB=-Al-=SUB=-19-=/SUB=-: experimental and theoretical studies
Authors: Gamzatov A. G.  , Sokolovsky V. V.  , Batdalov A. B.  , Aliev A. M.  , Kim D. -H.  , Yen N.H.  , Dan N. H.  , Yu S. -C.
Published: January 2023

The results of experimental and theoretical studies of magnetocaloric properties of a ribbon sample of alloy Ni45Co5Mn31Al19 in the range of T=80-350 K in magnetic fields of up to 8 T are given. This alloy demonstrates a first-order magnetostructural phase transition (MSPT) in the temperature range of 270 K, as well as a second-order transition --- at the Curie temperature of 294 K. The magnetocaloric effect (MCE) was studied both by the direct method of magnetic field modulation in cyclic fields up to 8 T and by the classical extractive method. Field dependence of MCE have a different nature for first- and second-order phase transitions. A reverse MCE near MSPT is irreversible, i.e. the final sample temperature is 0.75 K below the initial one. Theoretical studies of magnetic properties and MCE of the studied sample were performed by ab initio calculations and Monte Carlo modeling. Theoretical temperature dependences of MCE are characterized by a similar interval of effect manifestation in the region of martensitic transformation and a narrower interval in the region of austenite Curie temperature as compared to the experiments, which is conditioned by the presence of a heterogeneous mixed state of austenite in the experimental sample. On the whole, theoretical data qualitatively and quantitatively reproduce the experimental dependences. Keywords: magnetocaloric effect, cyclic fields, Heusler alloy, Monte Carlo method.
Luminescent properties of colloidal Ag-=SUB=-2-=/SUB=-S quantum dots for photocatalytic applications
Authors: Ovchinnikov O.V.  , Smirnov M.S.  , Aslanov S.V.  , Perepelitsa A.S.
Published: January 2023

The structural and optical properties of colloidal Ag2S quantum dots in various environments are investigated. With the help of transmission electron microscopy, X-ray diffraction and energy-dispersive X-ray analysis the formation of colloidal Ag2S quantum dots with an average size of 2-3 nm with a monoclinic crystal lattice, and Ag2S/SiO2 core-shell systems based on them, has been established. The change in the luminescence quantum yield of quantum dots with the change of the surface environment state is shown. The decoration of TiO2 nanoparticles of 10-15 nm in size with Ag2S quantum dots was performed and the influence of the structure of the interfaces of quantum dots and their environment (2-mercaptopropionic acid, water, ethylene glycol, SiO2 dielectric shell with a thickness of 0.6 nm and 2.0 nm) on the formation of TiO2-Ag2S heterosystems was analyzed. For Ag2S quantum dots passivated with 2-mercaptopropionic acid, signs of charge phototransfer after adsorption on TiO2 nanoparticles surface have been established. Signs of reactive oxygen species appearance due to charge phototransfer in heterosystem are enstablished, based on methylene blue photobleaching under excitation of heterosystem outside of TiO2 fundamental absorption region, Keywords: Quantum dots, photocatalysis, luminescence, titanium dioxide, silver sulfide.
Magnetostriction of the Fe-=SUB=-75-=/SUB=-Ga-=SUB=-25-x-=/SUB=-Z-=SUB=-x-=/SUB=- (Z=Al, Ge, Si) alloys: calculation by the magnetic torque method
Authors: Matyunina M. V.  , Zagrebin M. A.  , Sokolovskiy V. V.  , Buchelnikov V. D.
Published: January 2023

This work presents an ab initio study of the effect of a small addition of the third element of III and IV groups on the elastic and magnetoelastic properties of Fe75Ga25 alloy. The dependencies of the tetragonal elastic modulus C', magnetoelastic constant -b1, and the tetragonal magnetostrictive constant λ001 on the concentration of the Z-element in the cubic crystal structures A2 and D03 were obtained with the help of the density functional theory and the magnetic torque method in Fe75Ga25-xZx (Z=Al, Ge, Si) alloys (0≤ x≤6 at.%). It is shown that the addition of Al and Si atoms leads to an increase in the tetragonal elastic modulus compared to the Fe75Ga25 binary alloy. A correlation was established in the dependence equilibrium lattice constants a0(x) and λ001(x) in the studied ternary alloys for the A2 structure. Keywords: tetragonal magnetostriction constant, magnetoelastic constant, tetragonal shear modulus, magnetic torque method.
Thermal and magnetocaloric properties of manganites La-=SUB=-0.7-=/SUB=-Sr-=SUB=-0.3-x-=/SUB=-Ba-=SUB=-x-=/SUB=-MnO-=SUB=-3-=/SUB=-
Authors: Gadjiev A. B.  , Gamzatov A. G.  , Batdalov A. B.  , Hurshilova Z. A.  , Aliev A. M.
Published: January 2023

The results of a study of the effect of partial substitution of Sr2+ ions by Ba2+ ions on the thermophysical and magnetocaloric properties of manganite La0.7Sr0.3-xBaxMnO3 (x=0; 0.02; 0.05 and 0.10) in the temperature range 100-400 K and in a magnetic field up to 1.8 T. It is shown that such a substitution leads to a significant decrease in TC. In the behaviour of the thermal diffusivity eta(T) and thermal conductivity kappa(T) near TC, minima were found that are associated with both the scattering of phonons by local distortions of the crystal lattice and by spin fluctuations. The absolute values of thermal conductivity decrease with an increase in the disorder parameter. The magnetocaloric effect exhibits a weak dependence on the substitution level (x). Keywords: Magnetocaloric effect, manganites, phase transitions, heat capacity, thermal diffusivity, thermal conductivity.
Dzyaloshinskii-Moriya interaction in Pt/Co/Ir/Co/Pt synthetic ferrimagnets
Authors: Bezverkhnii A. I.  , Gubanov V. A.  , Sadovnikov A. V.  , Morgunov R. B.
Published: January 2023

We had found nonreciprocity of spin waves in Pt/Co/Ir/Co/Pt synthetic ferrimagnets by Brillouin light scattering technique. It is shown that the main contribution to the nonreciprocity of spin waves is made by the Dzyaloshinskii--Moriya interaction with an energy density D~ 1.7-2.3 erg/cm2. The energy density of the Dzyaloshinsky--Moriya interaction in Pt/Co/Ir/Co/Pt synthetic ferrimagnets is higher than its values in heterostructures with one Co layer Pt/Co(1 nm)/Ir ~1.4 erg/cm2. The D value of synthetic ferrimagnets decreases with increasing thickness of the Co thin layer. Keywords: synthetic ferrimagnets, perpendicular magnetic anisotropy, Brillouin light scattering, exchange interaction, Dzyaloshinskii--Moriya interaction .
Magneto-optical properties of nanoparticle dispersions based on Fe-=SUB=-3-=/SUB=-O-=SUB=-4-=/SUB=-, obtained by pulse laser ablation in a liquid
Authors: Solodova O.V.  , Sokolov A.E.  , Ivanova O.S.  , Volochaev M.N.  , Lapin I.N.  , Goncharova D.A.  , Svetlichnyi V.A.
Published: January 2023

The structure, optical and magneto-optical properties of colloidal solutions of iron oxide nanoparticles obtained by pulsed ablation in distilled water, both without additives and with various functional additives: gold-hydrochloric acid, silicon oxide, and polyvinylpyrrolidone, have been studied. It is shown that the main magnetic phase is magnetite Fe3O4. The size distribution of nanoparticles and the degree of their agglomeration depend on the additives. In the absence of the latter, a very wide of size distributions and strong agglomeration of particles are observed. The narrowest distribution curve with a maximum corresponding to ~7 nm and an almost complete absence of agglomeration are observed for particles synthesized in the presence of polyvinylpyrrolidone. The shape of the spectral dependence of magnetic circular dichroism, which generally corresponds to the spectrum of magnetite, undergoes some modifications for various additives, which is associated with defects in the distribution of iron ions between different positions in the crystal. Keywords: pulsed laser ablation, nanoparticles, colloidal solutions, magnetite, magnetic circular dichroism.
Magnetostructural features of phase transitions in the Mn-=SUB=-1-x-=/SUB=-Co-=SUB=-x-=/SUB=-NiGe system Part 2. Analysis
Authors: Mitsiuk V.I.  , Rimskiy G.S.  , Koledov V.V.  , Mashirov A.V.  , Val'kov V.I.  , Golovchan A.V.  , Kovalev O.E.
Published: January 2023

Within the framework of the model of interacting parameters of the magnetic and structural orders, taking into account the internal periodic magnetic field orthogonal to the exchange field, we analyzed the features of magnetostructural transitions in the Mn1-xCoxNiGe system. A qualitative description of changes in the nature of magnetic phase transitions from magnetostructural transitions of the 1st order paramagnetism-antiferromagnetism (x=0.05-0.1) to isostructural transitions of the 2nd order paramagnetism-ferromagnetism (x=0.15-0.8) with a change in the concentration of Co is presented. An explanation is given for the onset of irreversible magnetic-field-induced transitions at temperatures on the order of 5 K in strong magnetic fields, accompanied by a change in the saturation magnetization for samples x=0.15-0.8. The low-temperature inverse magnetocaloric effect at liquid helium temperatures is predicted for these samples. Keywords: irreversible magnetostructural first-order phase transition, helimagnetism, direct and inverse magnetocaloric effects.
Correlated accumulation of microcracks in impact damaged surface of α-quartz amorphized by Ar-=SUP=-+-=/SUP=- ions implantation
Authors: Shcherbakov I.P.  , Chmel A.E.
Published: January 2023

The microcrack accumulation in impact damaged α-quartz plates prior to and after the Ar+-ion implantation was studied with the acoustical emission (AE) method. The 40 keV implantation doses of 1014 and 1016 ion/cm2 were applied. The statistical analysis of the energy distribution in impact-induced AE time series detected in unirradiated samples showed a random (poissonian type) accumulation of defects which is specific for mechanical destruction of homogeneous brittle materials. The energy distribution in the AE time series excited when damaging the preliminary implanted samples followed a power law typical for the fracture of heterogeneous solids such as rocks, ceramics, etc. The optical photography evidenced a transition from brittle (prior to implantation) to ductile damage formation caused by the disturbed interconnectivity of the crystalline structure in irradiated specimens. Keywords: ion implantation, alpha quartz, impact damaging, acoustical emission.
Distribution of Tb-=SUP=-3+-=/SUP=- and Eu-=SUP=-3+-=/SUP=- cations in the C-Gd-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=- lattice according to photoluminescence and far IR spectra
Authors: Bakovets V.V.  , Dolgovesova I.P.  , Pivovarova T.D.  , Sheludyakova L.A.
Published: January 2023

In this work, we investigated the features of the photoluminescence of C-Gd2(1-x)TbxEuxO3 luminophores at x=1.0 and 2.5 mol%, which are associated with the distribution of Tb3+ and Eu3+ activator ions over the centrosymmetric C3i and noncentrosymmetric C2 positions of cations in the bixbyite lattice, as well as in the positions at the boundaries crystallites CS. We studied the phase transformations of the samples, changes in the morphology of crystallites, photoluminescence spectra, and spectra of the far infrared region 50-600 cm-1 with changes in the annealing modes of the initial products of the sol-gel synthesis Gd2(1-x)TbxEux(OH)y(CO3)z· n(H2O) at temperatures of 900 and 1200oC in air and hydrogen. Correlations have been established between changes in the characteristics of the samples and the parameters of their annealing. Based on the analysis of these correlations, the redistribution of activators over the indicated cation positions was determined, and a model was proposed for identifying infrared absorption bands in accordance with the localization of activators along the cationic sublattices C3i and C2. Keywords: Gd oxide, luminescence activators Tb3+ and Eu3+, annealing in air and in hydrogen, correlation of photoluminescence and far infrared spectra, distribution of activators in the lattice.
Ellipsometric characterization of VO-=SUB=-2-=/SUB=-, VO-=SUB=-2-=/SUB=- : Mg, VO-=SUB=-2-=/SUB=- : Ge nanocrystalline films
Authors: Castro R.A.  , Ilinskiy A.V.  , Smirnova L.M.  , Pashkevich M.Ye.  , Shadrin E.B.
Published: January 2023

The spectra of the refractive index n(λ) and the extinction coefficient k(λ) of thin VO2, VO2 : Mg, VO2 : Ge films were measured using the ellipsometric method. For an undoped VO2 film at a wavelength λ=632.8 nm, near the insulator-metal phase transition, the n(T) and k(T) thermal hysteresis loops were studied. An interpretation of the results is given on the base of the Moss relation, the idea of a change in n(T) and k(T) with an impurity variation of the material density, and also on the base of the ideology of the Coulomb transformation of the density of states function in strongly correlated materials. Keywords: ellipsometry, vanadium dioxide, insulator-metal phase transition, strongly correlated materials.
The emission spectrum of the ballistic gel impacted by the projectile
Authors: Biryukov D. A.  , Gerasimov D. N.  , Yurin E. I.
Published: January 2023

Results of studying the glow that occurs when a bullet passes through a ballistic gel are presented. This phenomenon is all the more interesting as the glow occurs in various areas of the gel, including those that have not contacted directly with the bullet. The emission spectrum of the gel consists mainly of a continuous component with atomic lines superimposed on it. The continuous component can be explained in different ways: one of the options is thermal radiation; however, the description of the observed phenomenon as luminescence is also not improbable. Keywords: ballistic gel, bullet, emission.
Low Frequency Magnetoelectric Sensor Without Bias Using Laminated Metglas/Quartz/Metglas Structure
Authors: Sun C.  , Yang W.  , He Y.  , Chen L.  , Dong C.  , Liang X.  , Chen H.  , Sun N.-X.
Published: January 2023

Tremendous progress has been made on boosting the performance of magnetoelecric sensor to detect low frequency magnetic field signal by frequency multiplication based on magnetolectric composites. In this paper, a novel magnetoelectric sensor based on the laminated Metglas/piezoelectric quartz crystal/Metglas composites structure is presented. The Metglas foils are bonded symmetrically on both sides of the X-cut quartz crystal plate with epoxy. Experiments showed that the ME composites sensor was able to achieved a limit of detection of 11 pT for a low frequency magnetic field 1 Hz without any bias field through frequency multiplication method. The noise power spectrum density of the sensor has also been tested to be 3.93·10-6 V/Hz1/2 at 1 Hz. The results indicate that the proposed sensor has favorable features, which provides a cost-effective and high-performance approach for low frequency magnetic field measurement. Keywords: Low frequency, limit of detection, magnetoelectric sensor, piezoelectric quartz crystal.
Thermal conductivity of nanofluids: influence of particle shape
Authors: Eidelman E. D.  , Vul` A. Y
Published: January 2023

The paper proposes a modified Maxwell formula applied to the calculation of the thermal conductivity of nanofluids. It is shown that the use of elongated particles or chains of nanoparticles leads to a significant increase in thermal conductivity. Theoretical estimates based on the proposed model are in good agreement with experimental data. Keywords: Thermal conductivity, nanofluids, elongated particles, chains of nanoparticles, Maxwell formula.
Charge carrier localization in InAs self-organized quantum dots
Authors: Kosarev A.N.  , Chaldyshev V.V.
Published: January 2023

We considered the problem of localization of electrons and holes taking for instance the pyramidal InAs quantum dots in GaAs. The problem of quantum mechanics was solved for the localizing potential taking into account the geometry, chemical composition and built-in fields of the mechanical stress and strain. We found that the strongest localization of both types of charge carriers can be achieved if the ratio of the pyramid height to its base is about 0.2. Keywords: quantum dots, elastic strain, charge carrier localization.
Superconducting noise-source for ultra-low temperatures
Authors: Kim T. M.  , Shitov S. V.
Published: January 2023

The device operates at temperatures <300 mK and comprises a hafnium microbridge and a superconducting aluminum tunnel junction both integrated into a common coplanar waveguide. The microbridge matches with a planar antenna and operates as an optical blackbody at frequencies 600-700 GHz. The coplanar terminal is the blackbody output in the 1-2 GHz frequency range. The microbridge temperature can be set in the range of 0.4-9 K and calibrated using the shot noise of the tunnel junction. Temperature modulation of each of the sources can be performed independently using a direct current which transit them from the superconducting to the normal state with characteristic times <0.1 ms and heating power ~ 1 μW. Keywords: Superconducting microbridge, superconducting tunnel junction, thermodynamic noise, shot noise, noise thermometry.
Long-term effects of the mmune cells introduction on the recipients endocrine system functional activity: experimental study
Authors:   Federal State Budgetary Scientific Institution «Research Institute of Fundamental and Clinical Immunology», Anikeeva Olga S. , Markova Evgeniya V. ,   Federal State Budgetary Scientific Institution «Research Institute of Fundamental and Clinical Immunology»
Published: January 2023

The plasticity of the main homeostatic systems immune and neuroendocrine allows the body to resist the actions of adverse factors, but, nevertheless, the latter can cause pathological changes or lead to a limitation in the function of these systems. The paper presents data demonstrating the long-term effects of the immune cells with different functional phenotypes transplantation performed during early postnatal ontogenesis on the syngeneic recipients endocrine system functional activity, assessed by the neuroactive steroid hormones level in the CNS and in blood serum. The relevance of this study is due to the active development of cellular technologies and their successful use in the treatment of many nosological forms of immunological, oncological and hematological diseases, which has significantly improved the survival rate and quality of patient’s life; however the mechanisms of the transplanted cells effect on the body as a whole remain insufficiently studied, especially in childhood, when the formation of regulatory connections of the main homeostatic systems of the body that maintain dynamic homeostasis is taking place, and it is difficult to predict the long-term effect of therapy, because, even with a directed effect on one of them, influence is exerted on the interconnected functioning of all these systems. Previously, we have shown that immune cells with different functional activities, which is characteristic of individuals with an active or passive type of behavior, after transplantation performed at different stages of ontogenesis, in a cytokine-mediated manner affect the change/formation of a certain neuroimmune status in syngeneic recipients, including the behavioral phenotype. The presented study shows that after a threefold administration of immune cells in the juvenile period, a certain hormonal status is formed in syngeneic recipients by puberty: in all recipients, after cell transplantation, the level of corticosterone in the brain and its separate structures, as well as in the peripheral blood serum, was relatively higher than that in animals raised without adoptive cell transfer; at the same time, there was a pronounced tendency to increase the level of testosterone in the blood serum, and different levels of testosterone were recorded in the hypothalamus, hippocampus, striatum, and frontal cortex. Distinctive features of the central and peripheral levels of corticosterone and testosterone in recipients after multiple transplantation of splenocytes in the late period of maturity are determined by the different functional phenotype of the injected immune cells.
Effects of therapeutic doses of heparin on MSC functional activity in modeling the mechanisms of osteointegration under in vitro cultivation
Authors:   Center of Immunology and Cellular Biotechnologies, IKBFU, Norkin Igor K. , Yurova Kristina A. ,   Center of Immunology and Cellular Biotechnologies, IKBFU, Khaziakhmatova Olga G ,   Center of Immunology and Cellular Biotechnologies, IKBFU, Malashchenko Vladimir V. ,   Center of Immunology and Cellular Biotechnologies, IKBFU, Ligatyuk Denis D. ,   Center of Immunology and Cellular Biotechnologies, IKBFU, Khlusov Igor A. ,   Siberian State Medical University (SSMU), Litvinova Larisa S. ,   Center of Immunology and Cellular Biotechnologies, IKBFU
Published: January 2023

The use of artificial materials in regenerative medicine is accompanied by the development of an inflammatory response and the initiation of blood clotting due to the contact of the implant with the soft tissues of the body. All this leads to the formation of thrombosis of the major and main arteries and the development of serious complications. To prevent the development of postoperative pathological conditions caused by hypercoagulable syndrome, classical therapeutic strategies with anticoagulants (mainly heparin) are used. However, the described treatment tactics lead to an interruption of the migration and adhesion processes of mesenchymal stem cells (MSC), which negatively affects the callus formation and the processes of osseointegration of the implant. The aim of this study was to investigate the effect of a suspension of HA nanoparticles in the presence of heparin in a gradient of therapeutic concentrations on migratory and proliferative activity of MSCs in human adipose tissue under in vitro cultivation conditions. Methods. To evaluate the migration and proliferation potential of MSC in the presence of HA nanosuspension and/or heparin, an electrode system for continuous observation — xCELLigence ® RTCA DP was used. Results. A significant decrease in the migratory activity and proliferative potential of MSC was observed under the conditions of their co-cultivation with HA nanosuspension in the presence/absence of heparin (0.5–1 IU/ml). onclusion. The results of the study may serve as a prerequisite for the development of new therapeutic approaches for the use of heparin in surgical patients at high risk of postoperative thrombosis after osteosynthesis.
Role of proteins STAT/SOCS and WNT signaling system in obesity
Authors:   Oryol State University named after I.S. Turgenev, Kulakova Anastasiia S.
Published: January 2023

Violation of adipogenesis leads to the formation of hypertrophic obesity. Hypertrophied adipocytes produce a large number of cytokines, including TNF-α, IL-6, IL-1β, IL-10. The mechanism of adipogenesis is complex and diverse, as it is influenced by numerous factors, including components of the STAT and WNT signaling systems. The search for possible markers of the development of metabolic diseases has led to interest in studying the involvement of STAT and WNT proteins, signaling systems, in the implementation of cytokine effects in obesity. The aim of the study was to assess the serum levels of cytokines TNF-α, IL-6, IL-1β, IL-10 in patients with overweight, obesity and metabolic syndrome, as well as the relationship of these indicators with the concentration of STAT and WNT proteins signaling systems. Materials and methods. The study included 118 people, including 28 people with overweight, 28 obese patients without signs of metabolic syndrome, 32 patients with metabolic syndrome, 30 apparently healthy individuals with normal body weight, matched by sex and age. The concentration of proteins in the blood serum was determined by enzyme immunoassay. Quantitative indicators were evaluated for compliance with the normal distribution using the Kolmogorov-Smirnov test. In the absence of a normal distribution, quantitative data were described using the median (Me) and the lower and upper quartiles (Q1 – Q3). The direction and closeness of the correlation between two quantitative indicators were assessed using the Spearman rank correlation coefficient (with a non-normal distribution of indicators). Differences between the indicators were considered statistically significant at p<0.05. Results. In patients with metabolic syndrome, obesity and overweight, a statistically significant increase in the concentration of pro- and anti-inflammatory (TNF-α, IL-6, IL-1β, IL-10) cytokines was found relative to the comparison group; either a direct noticeable or a direct moderate correlation was established between the level of pro-inflammatory cytokines and the level of STAT and WNT proteins signaling systems. The obtained data on the increase in the levels of the corresponding cytokines (TNF-α, IL-6, IL-1β, IL-10) in patients with overweight, obesity and metabolic syndrome against the background of changes in the concentration of proteins of the WNT signaling pathway and the level of STAT/SOCS proteins 1, 3, 6 can serve as biomarkers for early detection of metabolic disorders.
Community-Based Integrated Water Resources Conservation on Mount Penanggungan in Pasuruan, Jawa Timur
Authors: Satriagasa Muhammad Chrisna , Kusumandari Ambar , Suryatmojo Hatma , Fahmi Faizal Nur , Chasanah Uswatun
Published: January 2023

Mount Penanggungan’s watershed ecosystems, which play a crucial role in managing the water cycle, are in an alarming state right now. Community-based integrated water resources conservation efforts aim to restore the function of watersheds, particularly in terms of controlling the water cycle. The purpose of this article is to describe a variety of community-based water conservation efforts in Mount Penanggungan, Gempol District, Pasuruan, East Java. We encourage the local community to engage in integrated water resource conservation activities, such as engineering efforts, plastic waste processing, tree planting, education, and public awareness-raising. Community service students from UGM participate in these programs as live-in facilitators. Local communities now have the infrastructure necessary to engage in community-based water conservation, including both physical and non-physical infrastructure (biopore and rainwater harvester) but also non-physical infrastructure (awareness and knowledge). This activity must be continued in order to observe the growth and outcomes of the empowerment initiatives that have already been carried out.
On Hegel’s View of Dialectical Infinity
Authors: Hong Zhang
Published: January 2023

It is well known that the problem of finity and infinity is the basic problem of mathematics, and it is also the basic problem of Philosophy. From the perspective of philosophy and mathematics, this paper comprehensively reviews and analyzes Hegel’s view of dialectical infinity, introduces Engels’discussion on infinity, deeply analyzes the characteristics of the thought of actual infinity, and points out: Hegel’s thought of real infinity is completely different from the thought of actual infinity, the Being of infinity (objective infinity) is not equal to the completed infinity (subjective infinity), the mathematical limit is a real infinity, and real infinity is the inner law of infinite things and truth; the view of actual infinity views the objective material world from the viewpoint of static rather than motion, denying the contradiction between finity and infinity, so it is actually a downright idealist. In this paper, the author puts forward the Infinite Exchange Paradox, which strongly questions the idea of actual infinity in Hilbert Hotel Problem, and points out the internal irreconcilable contradiction in the idea of actual infinity. At the same time, we made a detailed comparison of Hegel’s view of infinity and the view of mathematical infinity, and on this basis, the author gives a complete definition of the view of dialectical infinity: abandoning the wrong aspects of the potential infinity and actual infinity, and actively absorbing correct aspects of both, that is, not only to recognize the existence and knowability of infinite objectivity, but also to admit the imcompletion of infinite process. The reexcavation of Hegel’s view of dialectical infinity and the criticism of the actual infinity thought aim to find possible philosophical solutions for Russell’s Paradox and the problem of Continuum Hypothesis.
Улус Дондуковых в первые годы правления наместника Убаши
Authors:   Kalmyk Scientific Center of the RAS (8, Ilishkin St., 358000 Elista, Russian Federation), Tsyuryumov Alexander V.
Published: January 2023

Introduction. The article deals with the earliest years of the young Kalmyk Viceroy Ubashi’s reign. Goals. The paper attempts an analysis of the Dondukovs’ arrival in Kalmyk Steppe during the mentioned period. Results. In 1762, Empress Catherine II granted Princess Vera Dondukova and her family a permission to move back to their uluses (estates). But the January 1763 return of Vera Dondukova and her son Alexey destabilized the political situation in Kalmyk Khanate, which resulted from immediate rumors suggesting a soon handover of power to the former to be followed by changes in the ulus system proper. Many would recall how Noyon Donduk-Ombo had led the bulk of the Volga Kalmyks to Kuban somewhat thirty years before, and in those circumstances the imperial government had been forced to forgive him and formalize his actual position as Kalmyk ruler. In fact, the Khanate was facing another wave of feuds. This time the Russian government chose to identify problems before they arose, and sought — with entreaties and threats — to normalize the situation in Kalmyk uluses. This historical fact attests to that the 18th century was witnessing gradual changes in methods of imperial nationalities policies employed.
«Живем в Калмыцкой степи обыкновенно, как и другие живут». Ики-Хурулов род на рубеже XIX–XX вв.
Authors:   Gorodovikov Kalmyk State University (11, Pushkin St., 358000 Elista, Russian Federation), Komandzhaev Alexandr N. , Komandzhaev Evgeniy A.
Published: January 2023

Introduction. The fact that Kalmyk past everyday life remains somewhat unexplored makes the study relevant enough to be tackled. Kalmyk historical literature virtually never viewed the issue as a subject of independent research. Only a few works by prerevolutionary and — even fewer — Soviet authors contain fragmentary references to certain aspects of Kalmyk life. In addition, topicality of the theme arises from the stern need to introduce new sources into scientific discourse, as well as ones to clarify and supplement the deeply-rooted conclusions and provisions of available works. Goals. The work sets a specific objective of characterizing some problems and concerns once faced by natives of Kalmyk Steppe (Astrakhan Governorate) through the example of Iki-Khurul Shabinar clan from Maloderbetovsky (Kalm. Baγa Dörvöd) Ulus. Materials and methods. The article investigates newly discovered records management papers housed at the National Archive of Kalmykia (collections ‘Kalmyk People’s Executive Department’ and ‘Executive Office of Maloderbetovsky Ulus’), and thus introduces the latter into scientific circulation. The study employs a complex of general scientific and special historical methods, with a fundamental role to be played by the civilizational/cultural and interdisciplinary approaches in combination with the principles of historicism and objectivity together supposed to yield maximum truthfulness in characterizing Kalmyk life during the watershed historical period examined. Conclusions. The mid-19th to early 20th centuries were witnessing dramatic changes in Kalmyk uluses, such as active integration of the region into Russia’s socioeconomic structure, intensified sedentarization trends, and significant migrations of Russian peasants to Kalmyk-inhabited steppes. This, of course, was reflected in many aspects of Kalmyk people’s life to be exemplified with facts faced by Iki-Khurul clan, namely: diminished nomadic pastoral areas, lack of water resources for sedentarized nomads, needs to stabilize available communications, social and other concerns.