bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of the Structure and Mechanisms of Wear of Solid-Lubricant Coatings of the TiN–Pb System
Authors: Lozovan A. A. , Betsofen S. Ya. , Savushkina S. V. , Lyakhovetsky M. A. , Lesnevsky L. N. , Nikolaev I. A. , Pavlov Yu. S. , Kubatina E. P. , Agureev L. E.
Published: April 2024

Сomposite solid lubricating coatings TiN–Pb with a thickness of ~2 μm were produced by co-sputtering of Ti and Pb cathodes of two separate magnetrons on titanium alloy VT6. The Pb content in the coating averages ~12 at. %. The inner layer is coating characterized by a uniform distribution of Pb, and the upper layer is characterized by the presence of islands with a high content of Pb. The coating structure is globular, predominantly containing nanometer-sized crystallites. The absence of a columnar structure of the coating is associated with a high content of Pb, which is insoluble in the TiN matrix and interrupts the growth of crystallites. X-ray diffraction analysis showed the presence of Pb, PbO, and TiN phases in the coatings. The diffraction lines are broadened, which indicates that the crystallite size is ~10–20 nm in the coating. Tribological tests of the TiN–Pb coating were carried out under conditions of low-amplitude friction – fretting wear in a wide range of loading parameters. In the full slip mode, a friction coefficient of ~0.25 is observed. During the transition from the full slip mode to the reciprocating slip mode, the energy dissipated during friction drops by more than three times, which is also reflected in a sharp decrease in the friction coefficient from 0.25 to 0.05.
Resistive Plate Chamber as Thermal Neutron Detector Based on B-10 Converter
Authors: Petrova M. O. , Bogdzel’ A. A. , Bodnarchuk V. I. , Daulbaev O. , Milkov V. M. , Kurilkin A. K. , Bulatov K. V. , Dmitriev A. V. , Babkin V. A.
Published: April 2024

Neutron-scattering methods for researching condensed matter allow obtaining information about the inner structure and dynamics of the sample under study. The creation of new high-fluxes neutron sources for studying of promising materials and various biological systems impose special requirements on the operating parameters of detector systems. New generation of thermal neutron detectors should have record-breaking characteristics in spatial and time resolution with high registration efficiency. The paper discusses the possibility of using and expected performance characteristics of 10B-RPC for thermal neutron detection as part of searching new solutions for the implementation of neutron scattering station detector systems.
Investigation of the Biodistribution of Gd0.5La0.5F3:Eu Nanoparticles in the Internal Tissues of Laboratory Mice Using X-Ray Computed Tomography and X-Ray Fluorescence Analysis
Authors: Polozhentsev O. E. , Khodakova D. V. , Goncharova A. S. , Pankin I. A. , Soldatov A. V.
Published: April 2024

The biodistribution of Gd0.5La0.5F3:Eu(15%) X-ray phosphor nanoparticles in the body and tissues of internal organs of balb/c laboratory mice was studied. Gd0.5La0.5F3:Eu(15%) nanoparticles were obtained by the hydrothermal synthesis at 250°C for 24 h. Using X-ray powder diffraction, transmission electron microscopy, and dynamic light scattering, it was shown that a hexagonal phase was formed in the resulting sample, and the average size of nanoparticles varied in the range 30–40 nm. In vivo experiments have shown that intravenous administration of an aqueous solution of nanoparticles accumulates the sample mainly in the liver and spleen, with the maximum concentration being reached during the first day. According to the results of post-mortem analysis of tissues by micro-CT, it was shown that these nanoparticles formed conglomerates, their distribution over the volume of the organ was homogeneous. X-ray fluorescent analysis of liver and spleen tissue fragments allowed for elemental analysis and mapping. Distribution maps of heavy elements in the composition of nanoparticles (Gd, La, Eu) were similar to Fe distribution maps, which indicated the uniform distribution of Gd0.5La0.5F3:Eu(15%) nanoparticles in the pulp of the internal tissues of the liver and spleen.
Effect of a Pulsed Magnetic Field on Heterodiffusion of Sn in α-Fe in the Paramagnetic Temperature Range
Authors: Fedotov A. A. , Voronin S. V. , Pokoev A. V.
Published: April 2024

The effect of a pulsed magnetic field on the bulk diffusion coefficient of Sn in α-Fe was experimentally studied in the range of magnetic field strengths 79.6–398.0 kА ⋅ m–1, in the frequency range 1–21 Hz at temperatures of 790 and 830°C. Using X-ray diffraction analysis, the pulsed magnetic field was found to have a considerable effect on the diffusion coefficient of Sn in α-Fe at 790°C. The observed behavior of the frequency dependence of the diffusion coefficient had a pronounced “resonance” character. The degree of influence of the magnetostriction constant of α-Fe in the paramagnetic region on the additional mass transfer under the influence of a magnetic field is discussed. A theoretical justification is given for the assumption that the “resonant” behavior of the diffusion coefficient is related to the phenomenon of dislocation retarding by the Cottrell atmosphere under the action of a pulsed magnetic field. The significant role of the interaction of elastic fields of defect complexes with the fields of magnetostrictive stresses α-Fe is noted.
Determination of the Thicknesses of Monolayer Coatings Exposed to Ion Bombardment by X-Ray Photoelectron Spectroscopy
Authors: Afanas’ev V. P. , Lobanova L. G. , Selyakov D. N. , Semenov-Shefov M. A.
Published: April 2024

The samples of monocrystalline silicon coated with golden nanolayers were investigated. The samples were obtained by two methods, namely, gold sputtering using Xe+ beam with the initial energy of 7 keV and the method of thermal deposition. Preliminary analysis of samples based on the deciphering of energy spectra of reflected protons with an initial energy of 25 keV was performed. By methods of X-ray photoelectron spectroscopy with angular resolution (Angle Resolved XPS) thicknesses of gold coatings on silicon were determined. Analysis of samples using X-ray photoelectron spectroscopy was performed by comparing the intensities of Au 4f and Si 2p maxima measured at different angles of photoelectron detection. The calculations carried out by traditional methods indicate a marked dependence of the calculated gold coating thickness on the angle of sight for the case of monolayer and submonolayer coatings. It is shown that such discrepancy is possible if gold is deposited on silicon in the form of clusters forming islands rather than in the form of a continuous homogeneous coating. The possibility of gold islands moving relative to silicon in the upper silicon layers that have been subjected to proton bombardment at sliding angles to the surface is discussed.
The Influence of Ta Coating on the Crystallization of Deformed Fe78Si13B9 and Al87Ni8Gd5 Amorphous Alloys
Authors: Chirkova V. V. , Abrosimova G. E. , Pershina E. A. , Volkov N. A. , Aronin A. S.
Published: April 2024

The influence of the free volume on the crystallization processes of Fe78Si13B9 and Al87Ni8Gd5 amorphous alloys was studied by X-ray diffraction. To study the influence of the free volume, two methods of amorphous alloys deformation were carried out: ultrasonic treatment and multiple rolling. After deformation, a protective coating was applied to the amorphous alloys. It is shown that the deposition of a protective coating with a higher vacancy formation energy compared to the vacancy formation energy in the amorphous alloys under study is an effective way to maintain the free volume in the amorphous phase, since it is thermodynamically unfavorable for the free volume to migrate from the amorphous phase into the coating material. Experimental data indicate that the preliminary deformation of amorphous alloys leads to an increase in the amount of free volume. An increase in the amount of free volume and its maintenance by protective coating contributes to a significant crystallization acceleration of Fe78Si13B9 and Al87Ni8Gd5 amorphous alloys. The results obtained expand the existing ideas about the processes of crystallization of amorphous alloys and indicate the possibility of developing materials with different structural characteristics and, consequently, with different physicochemical properties.
Investigation of Factors Determining the Efficiency of Interaction of Aluminum Alloys Activated with the Ga–In Eutectic with Water in Hydrogen Cartridges
Authors: Nizovskii A. I. , Shmakov A. N. , Kulikov A. V. , Suprun E. A. , Bukhtiyarov V. I.
Published: April 2024

Using high-resolution X-ray diffraction and synchrotron radiation, as well as and scanning electron microscopy, it has been shown that the observed high reactivity of commercial aluminum alloys activated with the Ga–In eutectic is associated with the formation of the Al–Ga–In eutectic along grain boundaries in the entire material volume. The loss of material activity during storage under atmospheric conditions is due to the oxidation of the eutectic components. Activation with pure gallium leads to formation of AlGax solid solution, which has low activity in the reaction with water under neutral pH.
Model of Structural Ordering of Vacancies and Formation of a Family of Ternary Compounds in I–III–VI Systems
Authors: Mazing D. S. , Aleksandrova О. А. , Moshnikov V. А.
Published: April 2024

A characteristic feature of AI–BIII–CVI ternary chalcogenide compounds, which has a significant effect on the possibility of controlling the functional properties of materials based on them, is a strong tendency to stoichiometry deviation. The existence of ordered vacancy compounds in nanocrystals of the AI–BIII–CVI system was substantiated using the triangulation method (N.A. Goryunova’s method for predicting the composition of diamond-like semiconductors). Taking into account the assumption of the formation of electrically neutral defect complexes consisting of a vacancy in the position of the group I atom \(2[0]_{{\text{I}}}^{{ - 1}}\) and a doubly ionized antistructural defect \({\text{In}}_{{\text{I}}}^{{ + 2}}\) vacancies are presented as a pseudo-element of the “zero group”, while the system is considered from the point of view of the concentration tetrahedron so that the triangulation operations are transformed into tetrahedration operations. In the presence of such a “virtual” element, instead of a single stoichiometric composition in the AI–BIII–CVI system, a set of ternary compounds with an ordered content of vacancies known from the literature is determined, corresponding to semiconductors with four bonds per individual atom.
On the Characteristics and Role of Cottrell Co-Segregations of Carbon and Hydrogen in Strain Aging and Embrittlement of a Number of Steels
Authors: Nechaev Yu. S. , Denisov E. A. , Shurygina N. A. , Cheretaeva A. O. , Morozov N. S. , Filippova V. P. , Alexandrova N. M.
Published: April 2024

The work is devoted to the study of the characteristics of Cottrell’s phase-like “atmospheres” (carbohydride-like cosegregations of carbon and hydrogen) on dislocations in the martensitic and ferritic components in high-strength austenitic steel with transformation-induced plasticity due to the problems of aging, hydrogen embrittlement and degradation of a number of steels during operation. Particular attention is paid to in-depth processing (new technique) and analysis of the thermal desorption spectra of hydrogen for a number of steels and iron (as a reference material). The methods of thermodynamic analysis, the methodology for determining the thermodynamic characteristics (hydrogen concentrations, activation energies and rate constants of desorption processes) and the nature of “hydrogen traps” by analyzing the most representative thermal desorption data, comparing with the corresponding data obtained by three-dimensional atomic probe tomography, and also comparisons with the corresponding theoretical data. The conducted studies have shown the possibility of the formation of Cottrell carbohydride-like cosegregations of carbon and hydrogen on dislocations in martensitic and ferritic phases in high-strength austenitic steel with high plasticity induced by transformation, in particular, they made it possible for the first time to determine the binding energies of hydrogen with carbohydride-like cosegregations of carbon and hydrogen on dislocations in martensitic and ferritic phases.
High-Resolution Spectroscopy of the ErCrO3 Crystal: A New Phase Transition?
Authors: Yablunovskiy A. , Chukalina E. P. , Yin L. Kh. , Popova M. N.
Published: April 2024

Infrared absorption spectra of the ErCrO3crystal in the region off−ftransitions in the Er3+ion are recorded for the first time. An analysis of high-resolution temperature-dependent spectra reveals a step atT′=47K on the temperature dependences of the characteristics of spectral lines, in addition to the features at temperatures of magnetic orderingTN= 133 K and spin-reorientation transitionTSR=9.3K. This feature can be associated with either a previously unknown phase transition or with local changes in the crystal structure. The shape of the lines at liquid helium temperatures indicates the presence of additional positions for Er3+ions in the ErCrO3crystal. Presumably, these are positions near uncontrolled impurities that enter the crystal during its growth by the solution–melt method and form regions with a distorted structure responsible for the occurrence of polarization.
Screening Properties of Pure Water and Dilute Aqueous Solutions
Authors: Shikin V.
Published: April 2024

Screening properties of water and its diluted solutions are described with a formalism treating the behavior of weakly conducting liquids within the theory of reversible chemical reactions called ionic equilibria. Its modification allows a qualitatively correct explanation of the observed details in the screening properties of dilute aqueous solutions, including the limiting case of pure water.
Controlling the Angular Divergence of Terahertz Radiation Generated by Single-Color Filaments Using Phase Optical Elements
Authors: Pushkarev D. V. , Rizaev G. E. , Kosareva O. G. , Seleznev L. V
Published: April 2024

We have experimentally obtained two-dimensional distributions of terahertz radiation generated by one or four filaments formed by phase optical elements in air. It has been demonstrated that the use of the phase mask reduces the propagation angles of terahertz beam by approximately one and a half times, which is due to the interference of terahertz radiation from four sources. The use of the Dammann grating slightly enlarges these angles.
Magnetic Helix in a Multilayer Ferromagnetic Nanoparticle and Its Rotation Induced by an Electric Current
Authors: Fraerman A. A
Published: April 2024

The dynamics of the magnetization induced by an electric current flowing in a multilayer nanoparticle is studied theoretically. A region of the parameters where the coherent rotation of a magnetic helix, which is formed in this system due to the magnetostatic interaction of ferromagnetic layers, has been determined analytically. Estimates indicate that the predicted nonlinear oscillation mode of the magnetization can be observed experimentally.
Evolution of the Luminescence Properties of Single CsPbBr3 Perovskite Nanocrystals During Photodegradation
Authors: Baitova V. A. , Knyazeva M. A. , Mukanov I. A. , Tarasevich A. O. , Naumov A. V. , Son A. G. , Kozyukhin S. A. , Eremchev I. Yu.
Published: April 2024

The evolution of the luminescence blinking of single CsPbBr3perovskite nanocrystals with a characteristic size of ~25 nm during photodegradation has been experimentally investigated. It has been demonstrated that the blue shift of the luminescence peak and a decrease in the average luminescence intensity are accompanied by the increasing role of nonradiative Auger processes underlying the charging mechanism of blinking. A method based on the analysis of photon antibunchingg2(0) and exciton and biexciton recombination rates is used to determine the blinking mechanism. The data obtained have made it possible to reveal a transition from the trapping to charging blinking mechanism with a change in the sizes of a CsPbBr3single nanocrystal.
Experimental Study of the Compressibility of a Helium Plasma at a Pressure up to 20 TPa
Authors: Mochalov M. A. , Il'kaev R. I. , Erunov S. V. , Blikov A. O. , Ogorodnikov V. A. , Elfimov S. E. , Arinin V. A. , Komrakov V. A. , Likhutov M. I.
Published: April 2024

A nonideal helium plasma has been compressed to a density of ρ ≈ 14 g/cm3at a pressure ofP≈20TPa (200Mbar) in a spherical two-cascade device. The design of the device has been presented and the thermodynamic parameters of the helium plasma reached in it have been estimated. Data on the dynamics of the external and internal cascades in the device used to choose the calculation method have been obtained in a preliminary experiment with a hemispherical prototype. The experiment has been performed on the X-ray complex at the Russian Federal Nuclear Center All-Russian Research Institute of Experimental Physics, which includes BIM 234.3000 betatrons with a boundary energy of 60 MeV used in the multipulse bremsstrahlung generation regime with a multichannel optoelectronic system of recording X-ray images. A high-current linear accelerator LIU-R-T and an image detector assembly consisting of photochromic ADC screens have been used in addition to betatrons to detect the compressed shell cavity.
Ab Initio Study of the Adsorption of Li and Na on the Surface of a MgCl2 Monolayer
Authors: Ustyuzhanina S. V. , Kistanov A. A.
Published: April 2024

Ab initio calculations have been performed to study the dynamic stability of a new MgCl2monolayer and the formation of point defects in it. The possibility of using the MgCl2monolayer in Li- and Na-ion batteries has been analyzed. It has been shown that the MgCl2monolayer has the dynamic stability but can contain point defects. These point defects can improve the adsorption capability of the MgCl2monolayer with respect to Li and Na atoms. The results obtained in this work indicate that the MgCl2monolayer is a promising material for application in Li- and Na-ion batteries.
Temperature Dependence of the Band Gap of Completely Fluorinated/Hydrogenated Carbon Nanotubes: The Role of One-Dimensional Chains
Authors: Katkov V. L. , Osipov V. A.
Published: April 2024

The temperature dependence of the band gap Eg(T) in zigzag single-walled carbon nanotubes at the maximum (50%) fluorination and hydrogenation has been theoretically investigated for three coating versions. It has been shown that the character of coating dramatically affects the dependence Eg(T), which may vary over a wide range from very weak (typical of pure carbon nanotubes) to strong (typical of bulk semiconductors). The character of the temperature behavior Eg(T) is directly related to the formation of one-dimensional alternating chains in nanotubes. The main factors determining this dependence are the diameter of carbon nanotube, impurity position, and impurity type.
Experimental Study of the Transfer Function of a Superconducting Gauss Neuron Prototype
Authors: Ionin A. S. , Karelina L. N. , Shuravin N. S. , Sidel'nikov M. S. , Razorenov F. A. , Egorov S. V. , Bol'ginov V. V.
Published: April 2024

The transfer function of a shunted two-junction interferometer, which was previously proposed as a basic element of superconducting neural networks based on radial basis functions, has been measured for the first time. The sample has been implemented in the form of a multilayer thin-film structure over a thick superconducting screen with the inductive supply of an input signal and the readout of an output signal. It has been found that the transfer function is the sum of the linear and periodic bell-shaped components. The linear component is likely due to the direct transfer of the input magnetic flux to the measuring circuit. The shape of the nonlinear component, which is the output signal of a Gauss neuron, can be approximately described by a Gaussian distribution function or, more precisely, by a parametric dependence derived theoretically in previous works. It has been shown that the transfer function of the Gauss neuron can depend on the choice of the working point of the measuring circuit, which promotes the development of integrated neural networks based on implemented elements.
Extended Analytical Model for the Description of Light Absorption Spectra of Linear Molecular Aggregates
Authors: Moritaka S. S. , Lebedev V. S.
Published: April 2024

We study optical properties of linear dye aggregates in which the transition dipole matrix elements of two monomer molecules forming their unit cell are not coplanar with the aggregate axis, and the Frenkel exciton is delocalized along this axis. An analytical model has been developed for the description of polarization effects in the light absorption spectra of such aggregates. It is shown that the nature of their optical spectra differs drastically from previously studied linear aggregates with a single molecule per unit cell. The developed theory contains simple formulas of the well-known Davydov–McRae–Kasha model for conventional linear aggregates as a particular case. A quantitative explanation of the experimental data is given for the absorption spectra of the pseudoisocyanine bromide dye aggregate.
Simultaneous Observation of the Cyclotron Resonances of Electrons and Holes in a HgTe/CdHgTe Double Quantum Well under “Optical Gate” Effect
Authors: Bovkun L. S. , Krishtopenko S. S. , Aleshkin V. Ya. , Mikhaylov N. N. , Dvoretskiy S. A. , Tepp F. , Orlita M. , Gavrilenko V. I. , Ikonnikov A. V.
Published: April 2024

Spectral studies of the photoconductivity in the temperature range of T = 5–70 K, as well as studies of the magneto-absorption and magnetotransport at T = 4.2 K, have been performed in a HgTe/CdHgTe heterostructure with a double quantum well under an “optical gate” effect. Studies of magneto-absorption spectra under the controlled optical exposure have made it possible to observe absorption lines caused by both the cyclotron resonances of electrons and holes simultaneously. The coexistence of electrons and holes in the HgTe/CdHgTe double quantum well with a relatively large bandgap (~80 meV) indicates the appearance of a strongly inhomogeneous light-induced distribution of charge carriers in the plane of the structure. Experimental results obtained clearly demonstrate disadvantages of the control of the Fermi level positions in heterostructures with HgTe/CdHgTe quantum wells by means of the optical gate.
Geobiochemical Characteristics of the Snow Cover of the White Sea Coast in 2021 and 2022
Authors: Kotova E. I. , Topchaya V. Yu. , Novikova Yu. V.
Published: April 2024

For two years (2021 and 2022) snow sampling carried out in the coastal zone of the Onega and Dvina Bays of the White Sea during the period of maximum snow accumulation (March). The snow was analyzed for the content of the main ions (Cl–, \({\text{SO}}_{4}^{{2 - }}\), Na+, Ca2+, K+); biogenic elements (phosphorus, silicon, nitrogen), pH and mineralization were determined. The algological composition of the snow cover was also studied. The results showed that the snow was slightly acidic (average pH 5.4). Cl– and Na+ were the main ions in the coastal zone; \({\text{SO}}_{4}^{{2 - }}\) and Ca2+ in the estuary zone. The high content of marine ions and mineralization were determined near the Paranikha Bay (Dvina Bay), where the release of sea water onto the ice is noted annually. Compared to previous studies, in which snow samples were taken in the costal zone, the content of marine ions in the territory under consideration is an order of magnitude higher. As a result of the influence of marine aerosols, the values of snow cover mineralization can reach 140–680 mg/L. The content of dissolved silicon in melt water is increased in the zone of influence of atmospheric emissions from urbanized territories (Arkhangelsk, Novodvinsk, Severodvinsk), as well as near the granite quarry on the coast of Onega Bay. During the study period, 14 taxa of microalgae (species and supraspecific taxa) belonging to the division Bacillariophyta were found in snow samples. The maximum value of the total number of microalgae (1.293 thousand cells/L.) in the snow cover was determined in 2022.
Ice and Snow Thickness of the IGAN Glacier in the Polar Urals from Ground-Based Radio-Echo Sounding 2019 and 2021
Authors: Lavrentiev I. I. , Nosenko G. A. , Glazovsky A. F. , Shein A. N. , Ivanov M. N. , Leopold Ya. K.
Published: April 2024

Small glaciers of the Polar Urals are at the limits of their existence. Their state and changes serve as an important natural indicator of modern climatic changes. In 2019 and 2021, we performed ground-based radar studies of one of these glaciers, the IGAN Glacier, to measure ice thickness and snow cover. We used Picor-Led (1600 MHz), and VIRL–7 (20 MHz) GPRs. According to these data, the glacier has an average thickness of 49 m, maximum 114 m. The glacier has a polythermal structure: a cold ice layer with an average thickness of 12 m (maximum 43 m), overlaps the temperate ice with an average thickness of 37 m (maximum 114 m in the upper part of the glacier). The volume of ice contained in the glacier (in its studied part) is 14.3 × 106 m3, of which 10.89 × 106 m3 is temperate ice and 3.44 × 106 m3 is cold ice. For comparison: according to the radar data of 1968, the total ice thickness then reached 150 m in the central part, and the thickness of the upper layer of cold ice was 40–50 m. Radar snow gauge survey allowed to build schemes of seasonal snow thickness distribution over the glacier surface in 2019 and 2021, where there is a general spatial pattern of snow thickness growth from 2 m on the glacier terminus to 8 m or more to the rear wall of the corrie, which is due to the significant influence of avalanche feeding and wind transport. The glacier has lost about 3.2 × 106 m3 of ice per last decade, if the rate of loss continues, it may disappear in 40–50 years. However, this process may have a non-linear nature, as it involves not only climatic factors, but also local terrain features, on the one hand contributing to a high accumulation of snow, on the other – the formation of a glacial lake during glacier retreat, which may increase ablation.
Chemical Composition of the Hydro-Cryogenic System of Lake Baikal: “Snow on Ice–Ice–Water Under-Ice”
Authors: Vorobyeva I. B. , Vlasova N. V. , Belozertseva I. A.
Published: April 2024

The results of studies of the chemical composition and the basic regularities of migration of macro- and microelements within the hydro-cryogenic system “snow on ice–ice–water under ice” obtained in the winter of 2016/17 in the waters of Lake Baikal are presented. Such investigation over the Lake area was carried out for the first time. It has been found that due to climatic conditions, dates of freeze-up (formation of the ice on the Lake) differ by 7–10 days from North to South, and the depth of snow on ice and its density change over the Lake area by 2 times, however there are some parts without snow. It was found that the changes in the pH indexes were identical across the whole Lake area – minimum pH values are present in the snow (from 5.59 to 7.39), average values – in the ice (6.01–7.50), and maximum values are noted in the water under ice (7.42–8.50). For the most part, increased quantities of suspended matter and an increase in the pH of snow were recorded near settlements, which is obviously a result of the anthropogenic influence. It was determined that the concentration of ions in the ice in relation to their content in the initial solutions decreases within the series: \({\text{NO}}_{2}^{ - }\) Cl– \({\text{SO}}_{4}^{{2 - }}\) \({\text{HCO}}_{3}^{ - }\). Among the cations, K+, Na+ ions are involved into the ice intensively, while the Ca2+ and Mg2+ – weakly. The ice phase is enriched with ammonium ions outside the settlements. Near settlements and in shallow water, quantity of salts in the ice may be close to or equal to their concentration in the water under ice. The coefficient of migration in the water (Kx) divide the chemical elements into two groups – the mobile ones and slow-moving elements. The first group includes Ca, Cu, Sr, Mg, Co, Zn, and Cd (Kx 1), the second one contains Ba, Mn, Si, Fe, Al, Ti, Ni, Cr, P, and K.
Microelements in Dust in the Snow Cover: a Case Study of the Cities of Tyumen and Tobolsk
Authors: Zakharchenko A. V. , Tigeev A. A.
Published: April 2024

Received April 5, 2023; revised May 10, 2023; accepted June 27, 2023Inhomogeneities of trace elements content in dust of snow cover were studied in two industrial Siberian cities Tobolsk and Tyumen. The clustering method was used, for which standardized values of the content of trace elements in the snow dust of both cities were used. Eight clusters have been identified, which were divided into two classes by location: Tyumen and Tobolsk. The classes were divided into groups: non-specific and specific ones, of which the two subgroups were distinguished: technogenic and natural. The average values of trace elements in nominal terms were calculated for each cluster. Clusters C1, C2, C4, C7, C8 are characterized by a high content of heavy metals V, Cr, Ni, Cu, Co, Zn, Cd, W, Pb. Background clusters C5 and C6 have a low content of trace elements. Specific technogenic C4 contains more copper than other clusters, and C2 contains more lead. Sources of the formation of technogenic clusters are emissions into the atmosphere of enterprises of the fuel and energy complex, foundry and machine-building industries, and transport. The heterogeneity of the content of microelements in the snow dust under background conditions is demonstrated. The microelements are divided into natural background (cluster C5) and the background with anthropogenic pollution with higher content of Ag and Sn (cluster C6). In urban conditions, a solid phase of snow with a low and minimal content of trace elements in dust (cluster C3) is formed. Increased content of Ni and a reduced content of Pb and Sc is noted in the C3 cluster relative to C5 щту. Using the Mann-Whitne test, it was revealed that the content of trace elements in snow dust within the cities Tyumen and Tobolsk are different for the following elements: Li, V, Cr, Cu, Zn, Ga, As, Rb, Sr, Y, Zr, Nb, Mo, Ag, Cd, Sb, Cs, Ba, Pb. Mean values in are higher than similar ones in Tyumen. The content of Zn, As, Rb, Sc elements in urban clusters differs by more than two times relative to the background ones. In the case of elements Sn, Cs, W, the content of them in the snow dust of Tyumen is higher than that of Tobolsk. The method of clustering makes possible to identify natural background values (C5) and to calculate more precise values of the coefficient Kc as well as to determine the index of the integral pollution. In Tobolsk, the index is indicative of high and dangerous level of pollution, especially in the zone of technogenic impact. The average level is typical for the city of Tyumen.
Analysis of the Main Factors Controlling the Formation of Subaerial Taliks, Using a One-Dimensional Mathematical Model. A Case Study for the Shestakovka River Basin (Central Yakutia)
Authors: Popov S. V. , Boronina A. S. , Lebedeva L. S.
Published: April 2024

Received March 9, 2023; revised September 7, 2023; accepted October 2, 2023This study presents a mathematical model of heat transfer in a subaerial talik. The model is based on the concepts presented in classical works on permafrost, as well as on the results of geological and geophysical research carried out in the Shestakovka River basin (Central Yakutia). This model is based on the solution of the classical Stefan problem on the moving of the phase transition boundaries for a multilayer and multiphase medium. The solution was calculated on a unstructured mesh. When the phase boundaries move, thawed or frozen layers of soil are formed or wedged out. The layers include: snow cover, seasonally thawed soil, seasonally frozen and frozen sand deposits, as well as soil-vegetative layer. Published empirical relationships were used to calculate thermophysical coefficients, which are presented in this article. Simple variants of the model were considered to clarify the contribution of various factors to the process of formation and evolution of taliks. It has been established that the presence of snow cover and soil-vegetative layer have the most significant effect on the formation of taliks. Calculations show that taliks are formed in the first years of the modeled period, in the presence of snow and the absence of soil-vegetative layer. The soil-vegetative layer, depending on its composition and moisture content (ice content), can prevent the formation and development of taliks. The authors do not consider cases where shrubs contribute to snow accumulation. The humidity and iciness of the layer of sand sediments located in Central Yakutia have practically no effect on this process.
The Snow Depth in Forests and Fields on Lowlands of Russia under the Current Climate Conditions
Authors: Sosnovsky A. V. , Osokin N. I.
Published: April 2024

Received August 11, 2023; revised August 27, 2023; accepted October 2, 2023Average values of maximum snow depths (MaxSD) estimated separately under conditions of  forests and fields on lowlands of Russia were compared during the past 29 years. It was found that MaxSD in the fields for the current climatic period 1991–2020 increased by 5% compared to the period 1966–1990 and decreased by 8% in the forests. For the periods 1966–1990, 1981–2010, and 1991–2020, the ratio of MaxSD in a forest to similar one in a field (which we refer to as the snow survey coefficient) has been constantly decreasing. The snow survey coefficients for these periods were equal to 1.24; 1.12 and 1.08, respectively. In 1991–2020, the greatest values of this ratio were obtained in the northeast of the European part of the territory of Russia (ETR) and in the south of Western Siberia, where the maximum thickness of snow cover in the forest was found to be significantly higher than in the field. The lowest values were observed in some areas of the ETR center as well as in south-east and south-west, and in the south of Eastern Siberia. Here, for the periods 2001–2010 and 2011–2020, the values of the snow survey coefficients were estimated as 1.07 and 1.03 respectively. The coefficient for 1991–2020 decreased, on average, by 12% compared to 1966–1990. The maximum decrease in this ratio – by 15–25% – occurred in the south-west of Eastern Siberia and in a larger part of the ETR in the south. In 2011–2020, the MaxSD values increased in forests in the south-east of the ETR by 5–15%, and decreased in the south-west and the west of the ETR by 15–25% compared to 1966–1990. At the same time in fields, the MaxSD increased by 15–30% in the east of the ETR and the south of Siberia and decreased in the center and south-west of the ETR by 10–15%. The average value of the MaxSD in the field for the period 2011–2020 increased by 6% compared to 1966–1990 and decreased in the forest by 10%. Relative to other periods, the greatest increase in MaxSD was observed in 2001–2010. In the period 2011–2020, the MaxSD both in the forest and in the field mainly decreased relative to the period 2001–2010. In the current climatic period (1991–2020), the tendency for equalization of the MaxSD in forests and fields has been confirmed.
EXPERIMENTAL ESTIMATE OF EROSION MECHANISM AT THE EARLY STAGE OF GULLY FORMATION1
Authors: Larionov G. A. , Krasnov S. F. , Litvin L. F. , Gorobets A. V. , Kobylchenko (Kuksina) L. V. , Kriuchkov N. R.
Published: April 2024

The article presents results of experiment and its theoretical justification aimed to study the mechanism and intensity of the early stage of gully head formation. The experiment was carried out using the jet installation that allows to change the angle of the water stream from 0.5 to 90° with the flow velocity of up to 6 m/s. The flow angle was changed with a 10° step, while the flow velocity was maintained in the range of 1.01–1.04 m/s. The intensity of soil erosion positively correlates with the flow angles (angles of attack) in the range from zero up to 40°. When the angle was increased to 50–90°, the intensity continuously declined. The lowest absolute values of erosion intensity were observed when the water flow was normal to the soil surface. There are two main reasons why the intensity of soil erosion changes with changing angle of stream flow; the first is hydraulic, the second is hydro-mechanical. The former determines weakening and destruction of inter-aggregate bonds by the water penetrating into the soil; the latter – by the combined vectors of forces of hydrodynamic head and forces keeping the particle (aggregate) in place. The experiment showed that the maximum impact of water jet on a separate soil particle occur at angle of 41°. The flow in a gully happens occasionally and the results obtained should be attributed to the early stage of erosion: the stage before formation of a so called gully headcut.
LOESS FORMATION IN NEW ZEALAND DURING THE LAST GLACIAL EPOCH AND UNDER MODERN CONDITIONS1
Authors: Borisova O. K.
Published: April 2024

The main territories for the development of Late Pleistocene loess are located in the inland regions of the Northern Hemisphere, so the very existence of loess in New Zealand, a region with a temperate maritime climate, is of undoubted scientific interest. The analysis of geological, geomorphological, paleogeographical and geochronological data on the distribution, structure and formation conditions of loess in New Zealand in the Late Pleistocene has been carried out. The study showed that in New Zealand, as in other regions of the temperate latitudes of the Southern Hemisphere, the accumulation of loess occurred mainly in the cold phases of the last climatic macrocycle: in the Early Pleniglacial, 80 (75)–(60) 55 ka BP; (2) during cooling within MIS 3, 45–40 ka BP on the South Island and 40–30 ka BP, with a peak of about 30 ka BP, on the North Island; (3) in the Late Pleniglacial, from 25 to 17–12 cal ka BP. Comparison of these stages with the Antarctica ice cores data shows their close relationship with global climate change. The article reviews data on the current conditions for the development of eolian processes and the formation of loess-like deposits in New Zealand. In contemporary conditions, eolian processes in New Zealand are concentrated within geomorphologically active territories, e. g. in river valleys with glacier feeding and an abundance of loose sediments, in areas with widespread coastal sand dunes, and in those territories where vegetation and soil disturbances promote wind erosion of the surface layers of unconsolidated sediments. Large-scale anthropogenic impact (destruction of forests, disruption of the herbaceous cover due to intensive grazing of livestock, especially sheep, ploughing of slopes on light weakly cohesive soils, etc.) to some extent makes the present interglacial conditions for the development of eolian processes in New Zealand similar to periglacial ones.
DEVELOPMENT OF THE MINIATURE ANALOGUE OF THE SCABLANDS OF THE WEST USA IN THE LOWER POOL OF ONE OF THE KARELIAN HYDROELECTRIC POWER STATIONS1
Authors: Lukashov A. A. , Smoktunovich T. L.
Published: April 2024

Until the end of the Late Pleistocene, the modern river valleys of most of Scandinavia remained buried under the cover of continental ice. The rivers of the region, including the Karelian ones, are distinguished by their geological youth, having formed as fluvial complexes only in the Holocene. The young age, combined with the strength of the crystalline rocks of the Baltic Shield, has affected the fact that the rivers here are characterized by the lack of development of the longitudinal profile. At the base of the thresholds, at which the flow acquires the character of rapid, the processes of formation of miniature scaffolds develop in places. A similar hydraulic situation developed at the front of the degrading glacier. The lower reaches of dams of hydraulic stations are also favorable for a powerful impact on the rock bed. Numerous traces of violent deep erosion, accompanied by the phenomena of indiscriminate erosion and hydrodynamic cavitation, can be found on the kilometer-long sections of the exposed rock bed of semi-mountain streams drained during hydraulic development.A miniature scaffold developed by powerful natural and technogenically provoked floods in the lower part of the large rapid Matkozhnia on the Nizhny Vyg River, in the zone of the White Sea-Baltic Canal, is indicative. Almost the entire route of the canal, starting from Vygozero, is laid along the valley of the Lower Vyg. Only in some sections between the locks, the channel bed was dug away from the river. There, the old valley is preserved either almost dehydrated or with a small amount of water in the rock bed. The bedrock is exposed along the entire riverbed. Small boulders and pebbles of different sizes and grades of rolling can be found only in scattered pockets along the river channel. There numerous glass–like forms of microrelief – with a diameter and a depth of up to the first meters – “glasses” and “wells” are formed on Precambrian crystalline rocks. The contribution of evorsia to the denudation of crystalline slates in the bottom of the Vyga Valley on the rapid Matkozhnia is very significant, although the evorsion-cavitation effect itself is carried out rarely and for a limited time. Similar processes of natural origin operated before the creation of reservoirs on rapid-waterfall sites in the Vyga Valley and other large rivers of Karelia; they were caused by natural factors. Emergency descents of water through high spillway dams could increase the destructive effect of the stream on its root bed. So, in particular, the formation of evorsion microforms in the bed of the Lower Vyg at the rapid Matkozhnia is partially technogenically caused. Karelian cavitation-evorsion complexes of forms associated with hydrospheric catastrophes can be considered as miniature analogues of giant Late Pleistocene scablands of the northwestern USA.
THE METHOD FOR CO-REGISTRATION OF DIGITAL TERRAIN DATA TO OBTAIN HYDROLOGICALLY CORRECT MODEL OF THE EARTH’S SURFACE1
Authors: Kharchenko S. V.
Published: April 2024

There are problems with the co-registration of digital terrain models which were created by drones to obtain useful data for a numerical hydrological or erosional modeling. The different surveys can be produced at different time of a day, in various seasons or even years, making it difficult spatially reference the data. Many co-registration algorithms usually perform the statistical fitting of point clouds or raster models. Such approach violates the hydrological correctness of the final data, it makes artifacts appearing, such as various escarps and visible joints. The search for the contour of “zero error” on the raster of elevations difference is the bases of presented algorithm. This contour is used for the stitching of original elevation models together. As criteria for the quality assessment of the final elevation models are used: 1) the statistical distributions of slope gradient, i.e. parameter that affects the results of modeling the water and sediment flows, slope stability, etc., 2) the constancy of the microcatchments geometric structure. The algorithm was tested on three sites located in plain, low-mountain and mid-mountain zones. In all examples, the high efficiency of the method was shown. At the same time, the technique was constructed for keeping the significant features of terrain morphology in data. The average slope does not deviate by more than 1° in comparison with the original data. The Spearman rank correlation of the slope varies in different cases at 0.9–0.99 (with an average value of 0.96). The coefficients of geometric similarity of microcatchment patterns on the final models in all cases show even larger values (1.09) than on the original data without any correction (0.98) in the areas their overlap.
SPECTRAL ANALYSIS OF LAND SURFACE WITH THE CONSTRUCTION OF A NEURAL NETWORK FOR GEMS SEARCH ON THE EXAMPLE OF THE LUK TIEN MOUNTAIN RANGE (NORTHERN VIETNAM)1
Authors: Sergeev I. S. , Kuksa K. A. , Glebova A. B.
Published: April 2024

The study area is located in the north of Vietnam in the province of Yen Bai and it is a large (14.5 × 6.5 × × 0.8 km) structural and denudational butte on the periphery of high-dissected low mountains Con Voi, and they are also slopes and bottoms of the neighbor rivers valleys. There are a lot of gemstone outcrops on the territory related with the vein formations in the strata of marbles. The area is relatively difficult to access for geological fieldworks. Therefore, in order to organize and conduct field geological prospecting work, the task was to obtain preliminary data on the possible localization of useful mineralization areas based on the analysis of available geological and geomorphological information. For the task, the spectral regularities of the land surface dissection spatially associated with veined geological formations in the near-surface part of the marble strata were studied, we used the discrete Fourier transform for this. The binary classification (for classes of potentially useful and useless areas) of the elevation amplitudes according with different spatial frequency of topographic dissection was provided with the simple neural network – two-layer perceptron. This algorithm is implemented on the basis of the scientific analysis libraries of the Python. The application of this technique made it possible to carry out a prediction for ruby-spinel mineralization in bedrock over a study area of more than 200 km2. Fieldworks in 2019 verified the predicted data by the ways of mineralogical and geochemical testing of the accessible part of the predicted points. An average estimate of the predictive strength of the method used was obtained as 35% – every third site predicted by the neural network actually contains the primary sources of rubies and spinels in the territory under consideration.
QUANTITATIVE LAWS OF A MORPOLOGICAL PATTERN FOR ABRASION SLOPES WITN A LANDSLIDE PROCESS WITHIN THE CRYOLITHOZONE (THE COASTS OF THE KANIN AND YAMAL PENINSULAS AS EXAMPLES)1
Authors: Victorov A. S. , Orlov T. V. , Arkhipova M. V. , Kapralova V. N. , Bondar V. V.
Published: April 2024

Coast landslide processes take a special place in the study and monitoring of processes in permafrost under the climate change, however, not much attention has been paid to the morphology and quantitative characteristics of the landslides. The aim of the work is to reveal quantitative relationships between the abrasion slopes and a landslide process for coasts within the cryolithozone, mainly in contact with the adjacent interfluves. The research is based on the interpretation of high-resolution space imagery at five costal sites of the Kanin and Yamal peninsulas. The study was focused on the morphological features of the upper part of the landslides at the border with the adjacent interfluve. This border is a combination of arc elements. Besides, there are arcuate residual sections of the interfluve surface, corresponding to different stages of landslide process, in some places on the slope. Analysis of the coastline from images gave us such characteristics of landslides as the length of the arcs forming the boundary, the length of the chords of the arcs, the arrows of the arcs, the average radii of curvature, the central angles of the arc, the angles of orientation of the chords with respect to the vector of the general strike of the corresponding section of the coastline. Some of these characteristics were obtained by direct measurement from satellite images, the others by calculation. The analysis included 30 samples with a volume of 103–183 elements. Statistical processing using Pearson’s goodness-of-fit test showed that in the vast majority of the sites, the distributions of the landslide upper boundary arc sizes, chords, arc arrows, and curvature radii, as well as central angles, correspond to a lognormal one. The chord orientations with respect to the strike of the site are normally distributed. The values of the distribution parameters of the studied quantitative characteristics of the landslide morphological features differ and depend on the physical-geographical and engineering-geocryological conditions of specific areas.