bluuebunny/crossref_metadata_2025 huggingface dataset:
Nano ltration puri cation of liquid radioactive waste
Authors: Kaptakov V. O , Milyutin V. V
Published: April 2024

The paper presents the results of testing the puri cation of real liquid radioactive waste from radionuclides - bottom residues of the Kola and Beloyarsk nuclear power plants (NPP), as well as low-level wastewater from the radiochemical building of the Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences (IPChE RAS) by the method of nano ltration (NF) using a polymer membrane manufactured by the Russian company «RM Nanotech». It has been shown that in the case of single-stage NF puri cation bottoms of the Kola (NPP), the coe cient of puri cation from 60Co is 2.8, while puri cation from 137Cs practically does not occur. When cleaning the bottom residues of the Beloyarsk NPP from 60Co using a ve-stage scheme, a coe cient of puri cation from 60Co equal to 388 was obtained. The combination of nano ltration puri cation and selective sorption of cesium on the ferrocyanide sorbent Temoksid-35 makes it possible to obtain a dry salt residue that is not related to radioactive waste. When using the method of nano ltration for the treatment of low-level wastewater of the Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences, the degree of puri cation was, %: 137Сs ~ 75; 90Sr ~ 91; 241Am ~ 99.5; 152Eu ~ 91; 239Pu ~ 99.5.
Modern radioecological situation at the site of the peaceful underground nuclear explosion "Crystal" and radionuclides in the surface waters of the adjacent territory (western Yakutia)
Authors: Artamonova S. Yu. , Bondareva L. G , Melgunov M. S , Simonova G. V
Published: April 2024

The radioecological situation at the site of the peaceful underground nuclear explosion «Crystal» after removal land cover and installation of the arti cial cover of rock from nearby quarry above the epicenter is considered. In 2012 the ambient dose equivalent rate of gamma radiation varied from 0.04 to 0.066 μSv/h, in 2019 the content of radionuclides in soils was (Bq/kg): 90Sr 2.5-5.3, 239,240Pu 0.03-25.4, 137Cs
E ect of temperature and absorbed dose on the rate of formation and composition of gaseous products of radiolysis of oil-bituminous rock
Authors: Jabbarova L. Yu. , Mustafayev I. I. , Gasanalieva N.
Published: April 2024

The results of study of gas formation at the radiation-thermal transformation of bituminous rocks of Kirmaku elds of Azerbaijan are adduced. The studies were carried out under the in uence of γ-radiation and accelerated electrons in a wide range of temperatures (20-500°C), absorbed dose (0-260 kGy), and dose rate (1 and 470 Gy/s).The in uence of temperature and adsorbed dose on the gas formation rate and content of products has been established. Estimates of technical and economic indicators of the process are given The results of these studies allow us to estimate the potential of the radiation-thermal method for producing oil products for various purposes.
Expansion of the Coverage of Ionosondes for Vertical Ionospheric Sounding by the Application of Satellite Navigation System
Authors: Smirnov V. M. , Smirnova E. V.
Published: April 2024

A possibility of the ionosonde coverage expansion due to applying navigation satellite systems for supplying with the reliable short-wave radio communication acting along extended radio paths including multihop radio paths. It is shown on the basis of processing experimental data that the functionality increase of the vertical sounding ionosonde can be provided using the hardware-software ionospheric sounding complex that uses data of navigation satellites. The application of this complex in the place, where the vertical sounding ionosonde is located, allows to obtain the detailed picture of the electron concentration distribution not only far from the ionosonde but also inside the sounding region itself, along the trajectories that all points located under the ionosphere follow and that cross the responsibility zone of the vertical sounding station. It is shown that it is possible to create the dense network of the ionospheric control on the basis of vertical sounding stations distributed over a territory and hardware-software complexes.
Numerical Simulation of Discrete Magnetic Breathers in Heisenberg Spin Chains with Additional Interactions
Authors: Bostrem I. G. , Ekomasov E. G. , Ovchinnikov A. S. , Sinitsyn V. E. , Fakhretdinov M. I.
Published: April 2024

A 1D model of a finite-length spin chain with the Dzyaloshinskii–Moriya interaction is considered. An algorithm for simulation of the problem is developed, and calculations that demonstrate the existence of discrete magnetic breathers of various types in the phase of forced ferromagnetism of a chiral helimagnet are presented. It is shown that the analysis with allowance for the Dzyaloshinskii–Moriya interaction yields a decrease in the amplitude of discrete magnetic breathers.
The Application of the Hybrid Projection Method for the Analysis
Authors: Chizhevskay Y. I. , Smol’nikov O. N. , Levitan B. A. , Zimin I. V. , Skobelev S. P.
Published: April 2024

The problem of scattering of a plane electromagnetic wave by a 2D periodic structure formed by absorbing spherical radially inhomogeneous dielectric elements is considered. The elements have the type of electromagnetic black holes located on a semi-infinite substrate. The numerical algorithm of the solution is developed. The algorithm is based on the hybrid projection method and takes into account the peculiarities of the black hole construction. The algorithm is generalized to the case, when black holes are situated on aperfectly conducting screen. New expressions for calculating the power absorbed by the structure elements are derived. The numerical results characterizing the efficiency of the structure absorption are presented.
Frequency Converters for the Terahertz and Infrared Ranges
Authors: Lerer A. M. , Makeev G. S. , Cherepanov V. V.
Published: April 2024

A method for solving the problem of nonlinear diffraction on two-dimensional periodic gratings of graphene ribbons has been developed. The third-order nonlinear conductivity of graphene under the action of two waves is taken into account, which is determined by the field of the pump wave, for which we use the field on graphene ribbons obtained by solving the linear diffraction problem. Numerical analysis shows the efficiency of nonlinear frequency conversion in the terahertz and infrared ranges when the frequencies of the incident pump and signal waves coincide with the resonant frequencies of the fundamental and higher order modes of surface plasmon polaritons in graphene ribbons.
Effect of Transionospheric Transmission Lines on the Probabilistic Characteristics of Reception of Phase-Shift Keyed Signals
Authors: Nazarov L. E. , Batanov V. V. , Kutuza B. G.
Published: April 2024

The paper presents methods for describing distortions of signals during their propagation in transionospheric transmission lines, which cause inter-symbol and inter-channel interferences. A technique for estimating the statistical characteristics of the interference noise has been developed and their estimation for digital phase-shift keyed signals is carried out by simulating transionospheric lines. The probabilistic characteristics and asymptotic probabilities of erroneous reception of the considered signals with an increase in their frequency band are estimated using the calculated statistical characteristics for the lines of the P range.
A Dielectric Waveguide Made of the High-Resistance Silicon and the Circuitry Based on This Waveguide
Authors: Parkhomenko M. P. , Kalenov D. S. , Eremin I. S. , Fedoseev N. A.
Published: April 2024

Optically and mechanically controlled attenuators and an electrically controlled phase shifter are developed on the basis of a dielectric waveguide made of the high-resistance silicon. The characteristics of the waveguide and elements developed on its basis are theoretically and experimentally determined in the frequency band 26–37 GHz.
Sets of Nonbinary Sequences with a Low Level of Mutual Correlation for Systems of Digital Information Transmission
Authors: Starodubtsev V. G.
Published: April 2024

The sets of nonbinary pseudorandom sequences (NPSs) for periods N = p^S– 1 20 000 (p = 3, 5,7, and 11) generated in finite fields GF(pS) whose power is V = N + 1 and the maximum of the module of peaks of the periodic autocorrelation function (PACF) and periodic cross-correlation function (PCCF) satisfy the bounds obtained by Sidel’nikov. In addition to the minimal polynomials of elements α and α^2 , where α is a primitive element of field GF(p^S), the minimal polynomials of elements α and α^(i_d)(i_d is the decimation index) are determined on the basis of which the new sets of NPSs can be formed with the equivalent correlation properties. Sets of indices i_d 2 are determined for various combinations of parameters p and S. The cases of even and odd values of parameter S are considered, for which the values of the PACF and PCCF with the maximum module are obtained and the number and values of different levels of correlation functions are determined.
Intrinsic Stimulated Intense Picosecond Emission in the Amplification Saturation Mode and the “Threshold” State of Electron-Hole Plasma in the AlxGa1 – xAs–GaAs–AlxGa1 – xAs Heterostructure
Authors: Ageeva N. N. , Bronevoi I. L. , Krivonosov A. N.
Published: April 2024

The review presents the third part of the experimental study of emission and the optoelectronic effects excited by it. At the beginning of a powerful optical picosecond pumping of the GaAs layer of the AlxGa1 – xAs–GaAs–AlxGa1 – xAs heterostructure, a picosecond emission has occurred in it. It has beenexperimentally proved that this is enhanced spontaneous (stimulated) emission with the propagation specifics in the heterostructure. It has been shown that the electron–hole plasma is maintained in a “threshold” state with an inversion of the electron population in a narrow energy range because of high emission intensity. In this regard, the electron temperature and therefore, their distribution between valleys, etc., becomes uniquely related to their density. It has been found that limiting the inversion meant the emission amplification saturation when the amplification is limited by the energy transport of charge carriers to the levels from which they are forced to recombine. It has been determined that the transport being slowed down by the heating of carriers because of their interaction with emission determines the dynamics of the emission as a whole and its spectral components when the temperature of the carriers is related to their density.
Throttle-Free Booster DC/DC Converter
Authors: Babenko V. P. , Bityukov V. K. , Lavrenov A. I.
Published: April 2024

The results of the analysis of the features of the charge pumping process in devices with switched capacitors, as well as the features of switching processes in transient operating modes, are presented. The methods by which a high efficiency of charge pumping is achieved are considered. Circuit modeling made it possible to refine the characteristics of processes, minimize conversion losses, formulate recommendations for choosing the parameters of converter elements, and generating control signals.
RNi (R = Gd and Dy) Compound-Based Magnetocaloric Materials
Authors: Kurganskay A. A. , Tereshina I. S.
Published: April 2024

High-performance materials for solid-state magnetic cooling in the temperature range of 1.5–100 K were developed. The magnetic and magnetocaloric properties of the new (R, R')Ni (R = Gd and R' = Dy) compounds and their hydrides were studied in the Curie temperature region. The main regularities in the behavior of the temperature dependences of the magnetocaloric effect for different compositions were established.
Geometrized Models of Two-Dimensional Electrostatic Electron Beams
Authors: Syrovoi V. A.
Published: April 2024

In the second approximation in coordinate system x^i , i = 1, 2, 3 connected with current tubes x^2=const , the equations of axisymmetric and plane-symmetrical electrostatic flows are formulated in three versions of the geometrized theory: in l-representation, longitudinal coordinate x^1 is not related to the physical parameters of the beam, phi- and W-representations, when as x^1 the potential of the electrostatic field is used, x^1=phi, or the potential of generalized momentum x^1=W.
Approximations of High-Order Fractional Transfer Functions
Authors: Korotkov A. S. , Kavruk A.
Published: April 2024

Various solutions of the problem of approximation of high-order fractional transfer functions are considered and a technique for solving the stability problem for such functions is shown. The existing solutions of the problem of approximating function pα are compared with those proposed on the basis of the least mean square error criterion. As an example, the results of filter simulation using the proposed solution are presented.
Investigation and Methods for Solving Problems of Scattering of Electromagnetic Waves on Three-Dimensional Anisotropic Dielectric Structures
Authors: Samokhin A. B. , Samokhina A. S.
Published: April 2024

The problems of scattering of electromagnetic waves by anisotropic dielectric structures are studied on the basis of volumetric singular integral equations. Existence and uniqueness theorems for solutions are given for a wide class of media, including lossless media. An efficient method for solving integral equations based on the collocation method and fast discrete Fourier transform algorithms is described.
Method for the Formation of Non-Binary Gordon – Mills – Welch Sequences for Digital Information Transmission Systems
Authors: Starodubtsev V. G.
Published: April 2024

In this paper, we develop a method for the formation of non-binary Gordon–Mills–Welch sequences (GMWSs) with a period of N = p^(mn) – 1 that are formed over field GF(p) based on the generalization of the binary sequence formation method. An expression for calculating the vector of decimation indices А_m,n,r of the basic M-sequence (MS) for summable sequences in the synthesis of GMWS is obtained. A method for the formation of non-binary GMWSs for arbitrary MSs is presented. The values of the components of the C_m,n,r shift vector of a basic MS are shown to depend on the distribution of digits at the positions of the pth representation of the corresponding decimation indices.
Increasing the Quality Indicators of the Functioning of Fuzzy Solvers at the Defuzzification Stage
Authors: Vassiliev A. E. , Vegner A. V. , Golubeva D. E. , Dotsenko A. S. , Karpenko V. A.
Published: April 2024

An approach to the implementation of the defuzzification procedure in microprocessor systems of fuzzy information processing is proposed. A computationally efficient model of the defuzzification operation is considered, based on the use of the concept of the measure of validity of a logical conclusion as a composition of the current values of the reliability of all elements of the conditional part of the rule that proposes this conclusion. The application of the approach provides a significant improvement in the quality of fuzzy approximation with little complexity of algorithmic and hardware-software tools. Examples of the use of this approach in practical problems are given.
Diffraction Theory of Propagation of High-Frequency Radio Waves in a Spherically Layered Ionospheric Radio Channel
Authors: Zernov N. N. , Bisyarin M. A. , Germ V. E.
Published: April 2024

A special analytical method is developed to describe the propagation of high-frequency electromagnetic waves emitted by a vertical point dipole from the surface of perfectly conducting Earth in a regular spherically layered background ionosphere. The basic representation of the wave field employs an integral over the set of wave components, each of which is related to a specific ray trajectory. Such an approach makes it possible to analytically take into account the effect of medium-scale 3D inclusions in the background ionosphere as an additional phase shift of the wave component with allowance for the distortion of its ray trajectory and to numerically calculate the effect of wave-field focusing.
Some Features of Scattering of a Plane ElectromaElectromagnetic Wave on a Plane Magnetodielectric Plate
Authors: Borisov D. A. , Skobelev S. P.
Published: April 2024

The two-dimensional problem of scattering of a plane electromagnetic wave on a flat homogeneous magnetodielectric plate of finite dimensions is considered. The problem is solved by the method of integral equations for auxiliary surface currents. Algebraization of integral equations was carried out using the collocation method and overlapping three-step basis functions. The results characterizing the efficiency of the proposed algorithm are presented. The influence of the geometric and material parameters of the plate on its effective scattering surface (ESS) in the direction of wave incidence, which characterizes the effects of “invisibility” of the plate, is studied. It is shown that the minimum of the specified ESS is achieved at a plate thickness close to the thickness that ensures the in-phase geometry of the geometric-optical rays that have passed through the plate and the rays that have passed by the plate. The ESS of a plate made of a material with positive and negative refractive indices is compared.
Using the Method of the Impedance Analog of the Sestroretskii Electromagnetic Space to Take Into Account the Influence of the Rocket Engine Plasma on the Radiation Pattern of the Onboard Antenna
Authors: Konov K. I. , Klimov K. N.
Published: April 2024

The problem of the influence of the rocket engine plume (REP) plasma on the radiation pattern (RP) of the onboard third stage antennas launch vehicle. The possibility of using the method of the impedance analog of the Sestroretskii electromagnetic space for solving this problem is shown. The distribution pattern of the plasma frequency in the REP is presented. The distribution patterns of the amplitude and phase of the magnetic field in the region under study are obtained. The RPs of the antenna system are presented, showing a significant shift in the direction of the main lobe and a change in its shape.
Onboard Phased Array Antenna of the Millimeter Wave Range
Authors: Ponomarev L. I. , Vasin A. A. , Krekhtunov V. M. , Terekhin O. V. , Komissarova E. V.
Published: April 2024

The requirements for the characteristics of phased antenna arrays of radar systems designed to probe the Earth’s surface from an aircraft are determined. The design features of an onboard pass-through phased array antenna with a monopulse irradiator are considered. The results of the calculation of the directivity characteristics and the magnitude of the gain coefficient losses of the phase-controlled antenna array are presented.
Algorithm for Estimating the Spectral Correlation Function Using the 2D Fast Fourier Transform
Authors: Shevgunov T. Ya.
Published: April 2024

An algorithm for estimating the spectral correlation function of cyclostationary random processes on the basis of their finite-time realization is proposed. The main algorithm steps are described and the main operations performed at each of them are formalized. The presented estimates of the spectral correlation function in the presence of a correlated stationary noise overlapping the analyzed cyclostationary random process in the frequency domain confirm the efficiency of the algorithm with a low signal-to-noise ratio. The number of required computational operations and the amount of computer memory required for storing intermediate results are estimated.
The influence of a strong local atmospheric disturbance on the resonant structure of the near field of a low-frequency loop antenna located in the Earth's ionosphere
Authors: Moshkov A. V.
Published: April 2024

Numerical calculations were carried out of the time dependence of the near electric field strength of an ionospheric loop antenna in the frequency range 1...10 kHz under the influence of a strong local disturbance floating in the atmosphere. A disturbance model in the form of a point source of energy was used. It is shown that as the disturbance region approaches frame antenna, the frequency and spatial resonant structure of the field strength changes qualitatively. Resonance near the lower hybrid frequency practically disappears, and resonance at small observation angles relative to the direction of the local geomagnetic field transforms into transverse resonance.
Modeling the frequency characteristics of the waveguide structure of a heterodyne receiver with sideband division for the range 211...275 GHz
Authors: Tretyakov I. V. , Khudchenko A. V. , Cherny R. A. , Likhachev S. F.
Published: April 2024

The microwave properties of the components of the waveguide structure of a heterodyne receiver in the 211...275 GHz range with sideband separation based on a pair of superconductor–insulator–superconductor (SIS) tunnel junctions are described. The following elements of the waveguide were studied structures: hybrid four-port splitter, directional coupler, T-shaped splitter body and waveguide absorber. S parameters were calculated for all elements. For hybrid divider additionally shows a phase balance with deviations of less than 0.4 degrees, and an amplitude balance within 1 dB. The expected level of quality of band separation in a band separation receiver using the studied waveguide elements is analyzed; its value is more than –25 dB. The waveguide elements are designed taking into account the fact that the block will be manufactured using precision milling; the minimum dimensions of the waveguide structure are limited by the diameter of the cutter used; in our case, 100 μm was chosen. All numerical calculations were performed using the finite interval method in the HFSS package.
Influence of conditions for the formation of hafnium oxide films on the structural and electrical properties of heterostructures.
Authors: Afanas'ev M. S. , Belorusov D. A. , Kiselyov D. A. , Luzanov V. A. , Chucheva G. V.
Published: April 2024

Hafnium oxide (HfO_2) films were synthesized onto silicon substrates by magnetron sputtering under various technological conditions. Research results presented structural composition of HfO2 films and electrical properties of heterostructures metal-insulator-semiconductor (Ni–HfO_2–Si) based on them.
The influence of noise and frequency distortions in the communication channel on a communication circuit based on a hyperbolic chaos generator.
Authors: Lyubchenko D. O. , Isaeva O. B.
Published: April 2024

The analysis of the possibility of using a chaotic communication scheme based onsynchronization of the receiver and transmitter, which used hyperbolic chaos generators. It is shown that useful information nonlinearly mixed into the transmitter signal can be detected by the receiver if it is in stable synchronization with the transmitted signal. Research has been conducted to confirm the hypothesis that the roughness, strong chaotic properties and noise-like broadband spectrum of this type of generator provide greater reliability and stability of transmission. The influence of noise and frequency distortions of the signal in the communication channel on the quality of information detection by the receiver is also shown.
Effect of crystallographic orientation on the phase transition of a finite TiNi shape memory alloy wafer.
Authors: Pavlov A. I. , Kartsev A. I. , Koledov V. V. , Lega P. V.
Published: April 2024

A simulation of a TiNi shape memory alloy plate was carried out at various crystallographic orientations using a free package for classical molecular dynamics LAMMPS. It was found that the crystallographic orientation of the plate has a significant effect on the phase transition temperature. The dependence of surface energy on temperature for crystallographic orientations (100), (110), (112), (122) was constructed. The stability of the model used was investigated, as a result of which its applicability in these calculations was confirmed.
Optical Antenna with Controlled Radiation Pattern for Application in Atmospheric Communication Channels
Authors: Vytovtov K. A. , Barabanova E. A. , Ivanov M. G.
Published: April 2024

A mathematical model of a new optical (1550 nm) antenna with an electrically controlled radiation pattern is presented. The working principle is considered, and the main parameters are calculated. As distinct from existing solutions, the antenna does not require convergence of beams at a distance of one half of wavelength. In the framework of the model, an electro-optical switch based on lithium niobate is calculated. Such antenna elements as a phase shifter and deflector are presented and calculated
Experiments on Coherent Addition of Chaotic Radio Pulses in a Wireless Channel
Authors: Kuzmin L. V. , Efremova E. V. , Itskov V. V. , Zubkov A. S.
Published: April 2024

The possibility of coherent addition of chaotic radio pulses in a wireless channel has been demonstrated experimentally. A method for obtaining chaotic radio pulses having an initial section with oscillations similar in shape is described. Chaotic radio pulses are generated and emitted by independent, structurally identical generators of chaotic oscillations, each of which is modulated by a sequence of video power pulses. It is shown that at the output of an antenna receiving signals from two emitters, coherent addition of chaotic radio pulses is observed.
Chemical Composition of Glycine soja (Fabaceae) Seeds from the Amur Region Territory
Authors: Lavrent’yeva S. I. , Ivachenko L. E. , Blinova A. A. , Bondarenko O. N. , Kuznetsova V. A.
Published: April 2024

Abstract—Wild soybean Glycine soja Sieb. Zucc., the wild ancestor of the cultivated soybean Glycine max (L.) Merr., is the source of many valuable genes missing in the genotype of cultivated soybean, including stress resistance to adverse environmental factors. The biochemical parameters (protein, oil, ascorbic acid, carotene, higher fatty acids, specific activity and multiple forms of enzymes of the oxidoreductase and hydrolase classes) of five forms of wild soybeans from the collection of the All-Russian Research Institute of Soybean, which are unique natural gene banks, were studied. The wild seeds were collected for in three districts of the Amur Region (Arkharinsky, Blagoveshchensk, Belogorsky) and grown on the crop rotation field. The obtained results of enzymatic activity (superoxide dismutase, catalase, peroxidase, polyphenol oxidase, ribonuclease, acid phosphatase, esterase and amylase) and biochemical parameters of the studied seeds of wild soybean forms allowed us to identify the form KA-1413 with high biochemical parameters (protein, oleic and linolenic acids), a low specific polyphenol oxidase activity, and an increased activity of superoxide dismutases, esterases and ribonucleases. Thus, the wild soybean form KA-1413 can be recommended as a source of dominant genes, which will help to increase the adaptive potential of new soybean varieties. The increased heterogeneity of multiple forms of SOD, AML, RNase and esterase in wild soybean seeds can be used as adaptation markers to environmental conditions.
Polysaccharides of Crotalaria alata and Gleditsia triacanthos as Components of a Growth Medium for Cultivation of Microfungi
Authors: Zakirova R. P. , Kodiralieva F. , Hwan A. M. , Rakhmanberdieva R. K.
Published: April 2024

Abstract—The study explores the possibility of using the seeds of Crotalaria alata L. and Gleditsia triacanthos L. (Fabaceae) as a growth medium stabilizer for cultivation of microfungi. A synergistic effect was achieved when agar-agar was combined with galactomannans from Crotalaria alata and Gleditsia triacanthos, in a ratio of 1.5 : 4 : 1. Such a composition made it possible to obtain a solid growth medium, similar in consistency and color to 2% agar-agar medium. To establish biological parameters of the developed medium, the spores of microfungi Stachybotrys alternans Bonord. (Stachybotrys Cordа) и Fusarium oxysporum Schr f. vasinfectum Bilai (Fusarium), were plated on the surface of the growth media using inoculation needle and incubated in a thermostat at 25–26 °C. It was shown that partial substitution of agar-agar with galactomannans contributes to the active growth of the microorganisms. The growth of the Stachybotrys alternans and Fusarium oxysporum fungal colonies on the galactomannans growth medium surpassed the control on the fifth day by 37.2 and 31.5%, and on the seventh day – by 8.7 and 11.1% respectively.
Adsorption of Cr(VI) by Nanosized Rutile under the Action of UV Radiation
Authors: Pechishcheva N. V. , Ordinartsev D. P. , Valeeva A. A. , Zaitseva P. V. , Korobitsyna A. D. , Sushnikova A. A. , Kim A. V. , Shunyaev K. Yu. , Rempel A. A.
Published: April 2024

the properties of nanosized sorbents prepared by high-energy milling from microcrystalline powder of titanium dioxide of rutile modification have been studied. It was established that milling to an average crystallite size of ~30 nm and ultraviolet illumination significantly improved the sorption properties of rutile with respect to chromium compared with those of the starting material and the ability of Cr(VI) to be reduced to Cr(III) in its presence. The maximum removal of Cr(VI) from aqueous solutions with a concentration of 50 mg/L was achieved under UV illumination in an acetate buffer medium at pH 4–5 and a content of ground rutile of 16.7 g/L. A mechanism of adsorption was proposed.
Solvation and Electrochemical Properties of Cobalt Tetrasulfophthalocyaninate in Water−N,N-Dimethylformamide Mixtures
Authors: Kovanova M. A. , Kuz’mina I. A. , Postnov A. S. , Korneva A. O. , Vashurin A. S.
Published: April 2024

The effect of the composition and properties of the mixed water–N,N-dimethylformamide solvent (χDMF = 0.0–1.0 mole fraction) on changes in the solvated state of cobalt 3(4),10(11),17(18),24(25)-tetrasulfophthalocyaninate (CoTSPc) was studied. The region of electrochemical stability of the CoTSPc–DMF electrolyte system at 25.0°C was determined. The study was performed by the interphase distribution method, electronic absorption spectroscopy, and cyclic voltammetry.
Acid Hydrolysis of Glycosyl–Glycose Bond Disaccharides in Water–Organic Media
Authors: Kushner M. A. , Seliverstova T. S. , Matusevich L. G.
Published: April 2024

Kinetic parameters (rate constants, energies and entropies of activation) of the acid-catalytic hydrolysis of reducing disaccharides cellobiose and lactose are determined in a wide range of mixtures of water and organic solvents (dioxane, acetone, DMSO, and acetic acid). It is shown that raising the content of the organic solvent accelerates the hydrolysis of the glycosidic bonds in different ways. The effect solvents have on the rate and mechanism of the studied reaction is discussed on the basis of solvation concepts.
Effect of Carbon on the Adsorption Properties of a Co/MgAl2O4 Catalyst for Carbon Monoxide Hydrogenation
Authors: Pankina G. V. , Kharlanov A. N. , Chernavskii P. A.
Published: April 2024

A study is performed of cobalt/MgAl2O4 catalysts promoted with glucose at Co/C molar ratios of 16.5, 3.2, and 1.6 via sequential deposition and codeposition. Magnetometry and IR spectroscopy of adsorbed CO show that raising the content of carbon in the catalyst contributes to the reduction of cobalt, regardless of how Co is introduced. Infrared spectroscopy reveals the main adsorption sites are cobalt cations and metallic Co. A strong contribution from adsorption sites characteristic of large Co particles is observed in systems synthesized via codeposition. Adsorption sites attributed to Co2+ and Coδ+ are structurally more homogeneous than ones attributed to metallic Co.
Analysis of a Thermodynamic Determination of the Surface Tension of a Two-Component Vapor–Liquid System
Authors: Zaitseva E. S. , Tovbin Yu. K.
Published: April 2024

A numerical analysis is performed of a thermodynamic determination of the surface tension (ST) of a vapor–liquid binary mixture and interfacial tension (IT) between two liquid phases as the excess value of free energy ΔF of a two-phase system with and without for a phase boundary. Calculations are made in the simplest version of the lattice gas model (LGM), allowing for the interaction of nearest neighbors in a quasi-chemical approximation. Each node of a two-component mixture in the LGM system can be occupied by mixture components A + B and vacancy V. The two main ways of calculating ST, expressed in terms of different partial contributions Miq to excess free energy ΔF (where i = A, B, V are vacancies; 1 ≤ q ≤ κ, q is the number of the monolayer inside the boundary; and κ is its width), are compared, as are calculations of ST and IT as excess free energy ΔF for a lattice model with no vacancies. The ambiguity of ST and IT values depending on the type of Miq functions is obtained by calculating the temperature dependence for a flat boundary and the dependence of ST and IT on droplet size at a fixed temperature. The role of vacancies in the LGM as the main mechanical characteristic of the system under the condition of strict phase equilibrium in three equilibria (mechanical, energy, and chemical) is discussed.
Study of Heptane and Toluene Decomposition during High-Energy Processing in a Planetary Mill Together with Titanium Powder
Authors: Aksenova V. V. , Kanunnikova O. M. , Ladyanov V. I.
Published: April 2024

Molecular spectroscopy in the UV and IR ranges is used to perform a comparative study of the decomposition of toluene and heptane during mechanical activation with titanium. It is shown that high-energy mechanical processing is effective for obtaining low-molecular-weight alkanes, the amounts of which are largely determined by the nature of the hydrocarbons. The effect the mill carrier’s speed of rotation has on the depth of hydrocarbon decomposition and the composition of products of the mechanical processing of the liquid phase is considered. It is shown that at a speed of 600 rpm, heptane begins to decompose at short periods of mechanical activation (MA), while toluene is stable up to 30 h MA. Considerable structural and chemical transformations occur in toluene after only 20–30 h of mechanical treatment at a speed of 890 rpm.
Organic Inhibitors of Metal Corrosion in Acid Solutions. II. Ways of Increasing the Protective Action and Main Groups of Compounds
Authors: Avdeev Ya. G. , Kuznetsov Yu. I.
Published: April 2024

Current approaches to creating mixed inhibitors of metal corrosion in acid solutions and possible pathways of their action on the corrosion process are reviewed. Quantitative approaches to assessing the mutual effect of the components of mixed inhibitors are analyzed, and criteria for the synergism of their action are discussed. The high efficiency of ternary mixed inhibitors based on triazole derivatives in the protection of different steels in high-temperature acid solutions (t = 100–180°C) and solutions of acid mixtures containing Fe(III) salts is shown. Important practical advantages and disadvantages of the different groups of inhibitors of metal corrosion in acidic media are discussed. Data on protecting metals in acidic media with so-called green inhibitors are summarized, and the prospects and discrepancies associated with their practical application are discussed. The need to search for technologies allowing the use of inhibited acid solutions that meet the environmental requirements of current production while simultaneously allowing for the hazard of solutions of the acids is shown.
Stability Constants of Nickel(II) Complexes with [2.2.2]Cryptand in Aqueous Ethanol Solutions
Authors: Isaeva V. A. , Pogodina E. I. , Katolikova A. S. , Sharnin V. A.
Published: April 2024

The stability constants of nickel(II) complexes with [2.2.2]cryptand in aqueous ethanol solutions with a variable concentration of the organic co-solvent were determined by potentiometry at Т = 298 K and µ → 0. It was found that mononuclear, binuclear, and protonated nickel(II) cryptates can form in solution, whose stability increases with the ethanol content. The Gibbs energies of nickel(II) ion transfer from water to the aqueous ethanol solvent were calculated using published data. The contributions of resolvation of reagents in water–ethanol mixtures to the change in the stability of nickel(II) complexes with [2.2.2]cryptand were evaluated.
Possible Ferromagnetism of a Nitrogen-Doped Carbon Material
Authors: Vasiliev V. P. , Kabachkov E. N. , Kulikov A. V. , Morozov Yu. G. , Shulga Yu. M.
Published: April 2024

A nitrogen-doped carbon material (NDCM) is synthesized by grinding a graphene oxide–melamine mixture in a planetary mill in which the balls and the body are both made of zirconium dioxide. In addition to a narrow signal at g = 2.0034, the EPR spectrum of the NDCM exhibits a broad signal at g = 2.08. Studies with a magnetometer show the NDCM is presumably a ferromagnetic material with a saturation magnetization at room temperature of approximately 0.02 emu/g and a coercive force of 100 Oe.
Volumetric Properties of a Solution of tert-Butyl Alcohol in Carbon Tetrachloride: MD Modeling
Authors: Anikeenko A. V. , Medvedev N. N.
Published: April 2024

Models of solutions of tert-butyl alcohol (TBA) in carbon tetrachloride (CTC) are obtained via all-atom molecular dynamics modeling. The excess volume of the solution and the apparent and intrinsic (geometric) volumes of both components are calculated throughout the range of concentrations. It is shown that the apparent and intrinsic molar volumes of TBA in the limit of low concentrations in solution are notably larger than in pure alcohol. At the same time, their values fall rapidly in a narrow range of concentrations (from 0 to 0.1 mole fractions), and then move almost linearly to their limit values in alcohol. It is found that such behavior of the volumetric characteristics of TBA is due to the specific association of alcohol at low concentrations because of the hydrogen bonding among TBA molecules.
Resonance Electron Capture by 5-Methyluridine and 3'-Deoxythymidine Molecules
Authors: Muftakhov M. V. , Tuktarov R. F.
Published: April 2024

Negative ion mass spectrometry is used to study processes of resonant electron attachment by 5‑methyluridine and 3'-deoxythymidine nucleoside molecules in the electron 0–14 eV range of energies. It is established that they are similar to those in nucleosides studied earlier (uridine, deoxyuridine, thymidine). The main channels of the fragmentation of molecular ions are revealed, and the absolute cross sections for the formation of fragment ions are determined. It is found that the intensity of the breaking the glycosidic bond in 3'-deoxythymidine in the region of low energies is two and a half orders of magnitude below the one in stavudine, testifying to the prospect of replacing the antiretroviral drug stavudine with 3'-deoxythymidine if radiation therapy is required for oncological diseases contracted as complications of HIV.
Interaction between Iron Nitrosyl Complexes and Phosphatidylcholine Membranes: A Fluorescence Study
Authors: Poletaeva D. A. , Faingold I. I. , Soldatova Yu. V. , Smolina A. V. , Savushkin M. A. , Sanina N. A. , Aldoshin S. M.
Published: April 2024

Fluorescent probes: 8-anilino-1-naphthalenesulfonate (ANS), eosin Y, and pyrene were used to study the interaction between liposomes and three nitrosyl iron complexes that are promising anti-inflammatory agents and cardioprotectors. It was shown that the studied complexes compete with ANS molecules for the bonding sites in a bilayer of liposomes. The incorporation of the complexes into the lipid bilayer was also studied according to the quenching of eosin Y and pyrene fluorescence. The data suggest that iron nitrosyl complexes interact with the phospholipids headgroups and can penetrate deeper into the hydrophobic center of a lipid bilayer, where they affect the packing of fatty acid chains. The pronounced membranotropic properties of the complexes correlated with their ability to inhibit lipid peroxidation. Complexes with high constants of pyrene bonding are the most effective antioxidants.
Metastable States of a Fluid Inside a Binodal in the Context of Cluster Variation
Authors: Votyakov E. V. , Tovbin Yu. K.
Published: April 2024

The behavior of the isotherm and molecular distributions inside the binodal is analyzed to solving an Ising model obtained on the basis of cluster variation for planar lattices with coordination numbers 3, 4, 6. It is found that the microscopic approach gives a probabilistic interpretation of the Maxwell macroscopic rule and explains how the isotherm a secant appears between the regions of coexistence of two phases. A region of no solutions (the region of degeneracy) is found inside the binodal, and the critical temperatures of degeneracy at which the nontrivial solution to the equations disappears are calculated for this region. The region of degeneracy inside the binodal expands and approaches the binodal curve as the temperature falls, so the degeneracy curve and the binodal become indistinguishable. Numerical iterative calculations are used to study the dependence of the region of no solution inside the binodal as a cluster grows. The critical temperature of degeneracy asymptotically approaches that of the binodal as the cluster grows. Existing ways of interpreting metastable states are discussed, along with as the correspondence between the new results and previously known mean-field (ignoring correlations) and quasi-chemical (considering only direct correlations) approximations, and an exact result of the Yang–Lee condensation theory.
Mechanism of the Thermolysis of Magnesium Perylenetetracarboxylates
Authors: Naifert S. A. , Zherebtsov D. A. , Uchaev D. A. , Morozov R. S. , Smolyakova K. R. , Orlova E. M. , Pan’kova A. A. , Sharova A. L.
Published: April 2024

Black-red and orange magnesium perylene-3,4,9,10-tetracarboxylate species are synthesized in the ion-exchange reaction at room temperature and by boiling an aqueous solution, respectively. Upon heating the two species to 500°C in argon, they reversibly lose 19–27 wt % of their crystallization water, and the products become black. X-ray diffraction analysis results show the preservation of the layered structure upon heating, which is confirmed via transmission electron microscopy. Exposure to a humid atmosphere rehydrates and restores the original structure. Thermolysis to 1000°С in argon produces a composite of MgO nanoparticles in a porous glassy carbon matrix. The stability of perylenetetracarboxylates up to 500°C makes them a promising candidate for synthesizing metal–organic frameworks.
The Effect of Temperature on the Volume Properties of L-Lysine in Aqueous and Aqueous Buffer Solutions
Authors: Tyunina E. Yu. , Tarasova G. N.
Published: April 2024

The behavior of L-lysine (Lys) in water and an aqueous buffer solution is studied by densimetry as the temperature varies from 288.15 to 313.15 K with an interval of 5 K. Based on the experimental density values of amino-acid solutions, the apparent molar volumes and partial molar volumes of Lys are determined at an infinite dilution in water and buffer solution at each temperature. The effects of temperature, medium, and amino-acid concentration on volumetric characteristics are revealed. The partial molar extensibility and their derivatives with respect to temperature, the values of which indicate the structurally destructive behavior of Lys in the studied solutions, are determined. It is found that the structurally destructive effects of Lys are enhanced in an aqueous buffer solution. It is shown that the partial molar volumes of amino-acid transfer from water to the buffer solution have positive values in the studied temperature range. The results obtained are discussed on the basis of various types of molecular interactions between a solute and a solvent using the Gurney model.
Phase Equilibria in H2O–CH3SO3H System: Experiment and Thermodynamic Modeling
Authors: Belova E. V. , Kapelushnikov A. S. , Voskov A. L.
Published: April 2024

Water activities in H2O–CH3SO3H system were obtained by the dew point method and by the static method of a vapor pressure measurement in a temperature range 288.15–323.15 K. Pitzer–Simonson–Clegg model parameters were calculated. The parameters describe adequately properties of a liquid phase in a temperature range 198.15–323.15 К and with an acid concentration up to 80 wt %. Stability parameters were determined for two solid phases, HMS·H2O and HMS·3H2O (HMS = CH3SO3H).
Liquid–Vapor Equilibrium in a Toluene–Methanol–N-Octylquinolinium Bromide System
Authors: Evdokimov A. N. , Kurzin A. V. , Tarazanov A. A. , Shornikova S. O. , Feofanova M. A.
Published: April 2024

The liquid–vapor equilibrium in the toluene–methanol–N-octylquinolinium bromide system has been studied at 101.3 kPa and various concentrations of the organic salt. It was shown that the quinolinium salt can be used as a separating agent for a toluene–methanol azeotrope mixture. For breaking the azeotrope and separating the mixed solvent into components, the N-octylquinolinium bromide concentration (in mole fractions) should be 0.55 or higher.
Fe- and Cu–Zn-Containing Catalysts Based on Natural Aluminosilicate Nanotubes and Zeolite H-ZSM-5 in the Hydrogenation of Carbon Dioxide
Authors: Smirnova E. M. , Evdokimenko N. D. , Reshetina M. V. , Demikhova N. R. , Kustov A. L. , Dunaev S. F. , Vinokurov V. A. , Glotov A. P.
Published: April 2024

Iron- and Cu–Zn-containing carbon dioxide hydrogenation catalysts based on natural aluminosilicate nanotubes and zeolite H-ZSM-5 are synthesized. Their textural and acidic properties are studied via low-temperature nitrogen adsorption–desorption, temperature-programmed desorption of ammonia, temperature-programmed reduction of hydrogen, and elemental analysis. The effect the temperatures of the reaction have on the conversion of CO2 and distribution of its product is studied. Catalysts based on aluminosilicate halloysite nanotubes exhibit methanol and С2–С4 hydrocarbon selectivities of 88 and 16%, respectively.
Initiation of Artificial Radioactivity of Impurity Elements in a Lead Cathode under Conditions of a Glow Discharge
Authors: Timashev S. F. , Savvatimova I. B. , Poteshin S. S. , Ryndya S. M. , Kargin N. I.
Published: April 2024

The possibility of initiation of nuclear chemical processes in the Pb cathode during a glow discharge in a low-temperature deuterium-containing nonequilibrium plasma leading to a significant (at times) decrease in the isotope content of some impurity elements (specifically, Zn) and increasing others (specifically, W, Fe, Mn, and Al). Such processes can be understood by introducing the existence in nuclear matter of metastable non-nucleon excitations of internal shaking (isu-states) formed by initiating actions on the nuclei of electrons with high (on chemical scales) kinetic energy Ee ~ 3–5 eV.
Photochemical Oxidation of Hexacyanoferrates in Aqueous Solutions
Authors: Tsybikova B. A. , Batoeva A. A. , Sizykh M. R , Aseev D. G.
Published: April 2024

The main kinetic laws governing the photochemical degradation of stable cyanide compounds are studied using the example of hexacyanoferrates (HCFs) in the combined {Solar/S2O2−882−} oxidation system under the action of solar radiation. The efficient oxidation of intermediate products (toxic free cyanides) to nontoxic final products proceeds in the combined {Solar/S2O2−882−} system, in addition to the complete degradation of [Fe(CN)6]3− complex. The high efficiency of HCFs oxidation in the combined system is attributed to a conjugated ion-radical mechanism that includes (along with direct photolysis) oxidation with the participation of highly reactive oxygen species (ROSes)—reactive secondary oxidizing agents consisting mostly of hydroxyl radicals generated in situ during the simultaneous alkali and light activation of persulfate with solar radiation. The effect anions (chlorides, sulfates, bicarbonates) and associated organic pollutants (xanthates, phenol) most characteristic of cyanide-containing industrial wastewater have on HCF oxidation in the {Solar/S2O2−882−} system is studied. The studied anions promote HCF photochemical oxidation in a wide range of concentrations (1–10 mM).