bluuebunny/crossref_metadata_2025 huggingface dataset:
PALEOCENE GLAUCONITE OF THE NEAR-VOLGA MONOCLINE OF SUBMARINE VOLCANIC-SEDIMENTARY GENESIS
Authors: Nikulin Iv. Iv. , Boeva N. M. , Soboleva S. V. , Bortnikov N. S.
Published: April 2024

A new concept of the formation of glauconite from the Paleocene deposits of the sedimentary cover of the southwestern part of the Near-Volga monocline is presented – it was formed as a result of halmyrolysis of ash material in lake conditions. Glauconitization is confined to the Paleogene thermal maximum and the periphery of active volcanism along the entire mobile belt. In this connection, it is widely distributed in the Paleogene deposits. Structural and crystal-chemical features of glauconite, stages of crystallization of its aggregates, paragenetic associations with smectite, kaolinite, and zeolite, as well as the presence of ore minerals, indicate its authigenic origin. The authigenic origin is confined to the formations of temporary, episodically submerging shallow marine basins. An applied scheme of discrimination of glauconites by their crystallochemical features has been developed. The discrimination diagram can be used to determine the specific conditions of the sedimentation basin, which are expressed in the progradation cycles of glauconite accumulation. The cycles were controlled by induced depressions within the Russian plate.
PLATINUM-PALLADIUM OCCURRENCE VASILINOVSKOE: A NEW TYPE OF NOBLE-METAL MINERALIZATION IN THE URALS
Authors: Vikentyev I. V. , Tyukova E. E. , Mokri V. D. , Ivanova Yu. N. , Varlamov D. A. , Shuisky A. S. , Groznova E. O. , Sobolev I. D. , Bortnikov N. S.
Published: April 2024

For the first time, a new noble-metal (Pt–Au–Pd) Vasilinovskoe ore occurrence discovered near the village of Kharp in the Yamalo-Nenets Autonomous Okrug is described. It is associated with amphibolized gabbroids and subordinate pyroxenites of the Kershor complex, dated mainly to the Late Ordovician. In these rocks, mineralization zones with an apparent thickness from 0.5 to 50 m (sulfides 3–5 vol.%, occasionally more) are developed. In areas with scattered or finely nested sulfide inclusions, feldspar-quartz, epidote and other veins are often present. According to assay data, in substantially sulfide 0.5–1 kg samples of these, in general, low–sulfide zones, the Pd content reaches 1.4 g/t, Au – 0.8 g/t, and Pt – 0.2 g/t. PGE minerals are represented by abundant secretions of micron–sized palladium tellurides – merenskite PdTe2, temagamite Pd3HgTe3, kotulskite PdTe, as well as other noble metal compounds – sadberite PdSb, arsenopalladinite Pd8(As,Sb)3 and others. In addition to these palladium minerals, the magnetite–chalcopyrite–pyrite association contains microinclusions of native silver, native bismuth and native tin. In the later polysulfide–feldspar–carbonate–quartz association, Au and Ag tellurides, native gold (including Hg-bearing), Se-containing argentite, greenockite are found. The formation of parageneses of precious metals is associated with late magmatic processes, as well as with redistribution by subsequent magmatogenic hydrothermal fluids, up to a temperature of ~250°C; pressure decreased from ~0.9–1.3 to ~0.4–0.5 kbar.
THE WEST SIBERIAN SEDIMENTARY BASIN. AN ORIGIN WITHOUT STRONG CRUSTAL STRETCHING – THE SUPERDEEP DRILLING DATA ANALYSIS
Authors: Artyushkov E. V. , Chekhovich P. A.
Published: April 2024

Mechanism of formation of large sedimentary basins on the continents is among the main problems in geodynamics. The formation of such structures far from convergent plate boundaries is most often explained by intense stretching of the lithospheric layer - rifting. This should be followed by a large and prolonged crustal subsidence due to cooling of the stretched lithosphere. A characteristic feature of the post-rift subsidence is a decrease in its rate in time - several times over a hundred million years. Rifting in the West Siberian Basin was associated with the formation of Permian-Triassic graben-rifts. The subsequent (post-rift) subsidence is considered by many researchers as a cause of formation of a thick layer of Mesozoic and Cenozoic sediments in the basin. Over the 86 Ma that passed from the beginning of the Middle Triassic to the end of the Middle Jurassic, the rate of post-rift subsidence should have decreased by about a factor of three. In fact, the opposite trend took place. Judging by the data of the Tyumen (SG-6) and En-Yakhin (SG-7) superdeep wells drilled in the north of the basin, the rate of crustal subsidence increased several times during this period of time. Such a sharp difference between the expected post-rift subsidence and the actual subsidence of the crust indicates that lithospheric stretching was not the main subsidence mechanism, and it could provide only a small part of the subsidence. Under such circumstances, the main cause of the subsidence should be contraction of rocks in the Earth’s crust due to prograde metamorphism.
MONITORING OF ARSENIC AND MERCURY CONTENT IN AGROECOSYSTEMS OF THE CENTRAL CHERNOZEMIC REGION OF RUSSIA
Authors: Lukin S. V.
Published: April 2024

The work analyzed the results of state agroecological monitoring of soils carried out in the southwestern part of the forest-steppe zone of the Central Chernozemic region of Russia. It was found that the average gross content of As and Hg in horizon A of arable chernozem of the typical forest-steppe zone of the Central Chernozemic region is 4.18 and 0.022 mg/kg, respectively. In the parent rock (C), the content of As is 1.38 times higher, and Hg is 2.22 times lower than in A. In the agroecosystems of the Belgorod region organic fertilizers are the main source of As and Hg, but this does not pose a danger to soil pollution and crop production. The highest average As content (0.020 mg/kg) was found in winter wheat grains, peas and sunflower seeds, and the lowest (0.016 mg/kg) was found in corn and soybean grains. The highest content of Hg is characterized by barley grains (0.006 mg/kg) and winter wheat (0.007 mg/kg), and the lowest content of this element (0.002 mg/kg) was noted in esparcet hay. Exceeding the levels of maximum allowable concentration of As and Hg for food grains and maximum allowable level for feed products was not revealed in the studies.
THE ZABAIKALIAN PARAMETRIC BOREHOLE: A FIRST EVIDENCE ABOUT DEEP STRUCTURE OF THE BORSHCHOVOCHNY METAMORPHIC CORE COMPLEX
Authors: Petrov O. V. , Kashubin S. N. , Gladkochub D. P. , Donskaya T. V. , Morozov A. F. , Kudryavtsev I. V. , Milshtein E. D. , Gorbachev V. I. , Narkisova V. V.
Published: April 2024

The Zabaikalian parametric borehole drilled out a metamorphic core complex on the reference geological and geophysical profile within the Central Asian fold belt, south of the Mongol-Okhotsk suture zone. In the section of the borehole drilled to a depth of 2600 m, a set of geophysical, geological and laboratory-analytical studies identified three main structural elements of metamorphic core complexes: the upper plate, detachment, and the lower plate. The upper plate (weakly metamorphosed rocks) is represented by serpentinite melange, which is separated from the underlying rocks of the lower plate by a zone of chlorite breccias (detachment). The lower plate, which is part of the crystalline basement complex, includes rocks of granite-schist and granite-plagiogneiss subcomplexes. The granite-schist subcomplex is composed of mafic and intermediate schist with amphibolites and quartzites. Biotite granite is widespread in the section; it forms layered veins with signs of synkinematic formations. According to preliminary estimates, the age of biotite granite is about 130 Ma. The schist is characterized by mylonite structure at intervals of interbedding with biotite granite veins. In accordance with data of geophysical surveys in the borehole and the petrophysical characteristics of cored rocks, the mylonite zone is the provenance of a series of inclined reflectors on the seismic reflection-CDP section, which can be traced to a depth of at least 10 km. The granite-plagiogneiss subcomplex is represented by plagiogneiss, leucogranites, and gneissic granites. In the Zabaikalian parametric borehole, a detailed section of the orshchovochny metamorphic core complex, fully characterized by core samples, of the was obtained, which should be considered as a reference for studying these structures. The investigation of this section will answer later many questions about the formation and evolution of the Central Asian fold belt.
THE FIRST RECORD OF A REPRESENTATIVE OF THE TOARCIAN-EARLY AALENIAN BELEMNITES IN KIMBERLITES OF THE OBNAZHENNAYA PIPE (NORTHEASTERN SIBERIAN PLATFORM)
Authors: Dzyuba O. S. , Grinenko V. S. , Oshchepkova М. G. , Shurygin B. N.
Published: April 2024

Berlites of the Obnazhennaya pipe of the Kuoika kimberlite field (northeastern Siberian Platform, Olenyok uplift), a rostrum fragment of a representative of Toarcian–Early Aalenian (latest Early Jurassic–earliest Middle Jurassic) belemnites was found for the first time, namely Arcobelus cf. krimholzi (Sachs, 1970). It is shown that belemnite records previously known from here and dated to the Late Jurassic or Early Cretaceous, may be of Bajocian–Bathonian (Middle Jurassic) age. The stage of kimberlite magmatism of 177 ± 1.5 Ma, recently established in the northeastern part of the Siberian craton according to U–Pb geochronological data, falls on the time of the existence of belemnites of the genus Arcobelus. The estimated Late Bajocian–Early Bathonian age of the representative of the genus Pachyteuthis previously found in kimberlites of the Obnazhennaya pipe is consistent with the 40Ar/39Ar age (167 Ma) as well as with the age based on some paleomagnetic data (168 ± 11 Ma) reported for the pipe. In the paleogeographic schemes of the northeastern part of the Siberian Platform during the Toarcian–Early Bathonian interval, the inner part of the shelf should be extended to the territory of the Kuoika kimberlite field, taking into account the new data on belemnites.
OXYGEN ISOTOPE FRACTIONATION IN THE SILICATE-CARBONATE SYSTEM DURING THE ROCK FORMATION OF THE KOVDOR MASSIF (KOLA PENINSULA)
Authors: Dubinina E. O. , Morozova A. S. , Rass I. T. , Avdeenko A. S.
Published: April 2024

For the first time the δ18O values both in carbonate and non-carbonate (Ol, Phl, Mt) components of the rocks (calcite carbonatites, phoscorites, ijolites, turyaites) of the Kovdor massif were studied to clarify the role of contamination processes, retrograde exchange, and high-temperature fractionation in the igneous system. It has been established that the processes of crustal contamination are not recorded in the isotopic characteristics of the silicate part of the rocks, and the δ18О values of olivine, phlogopite, and magnetite are lowered compare to the compositions attributed to equilibrium with mantle peridotite. At the same time, the carbonate component of the rocks shows complementary enrichment in the 18O isotope with respect to the composition of derivatives of mantle melts. Estimates of the δ18О closure temperature of the olivine and the rates of rock cooling do not support the hypothesis of retrograde isotopic exchange. A hypothesis is proposed about the presence of a stage of redistribution of oxygen isotopes between the silicate and carbonate components of melts in the magmatic system, which took place before the formation of the Kovdor massif and its cooling. According to oxygen isotope data, the carbonate component could sharply predominate (1.5–4.5 times) over the silicate component during the equilibration.
PREDICTION OF ENVIRONMENT STATE IMPACT IN AREA OF A COPPER-NICKEL PLANT ON THE BASIS OF BALANCED IDENTIFICATION TECHNOLOGY
Authors: Sokolov A. V. , Gashkina N. A. , Moiseenko T. I.
Published: April 2024

The article deals with modeling the dynamics of nickel concentration in soils, water and bottom sediments of lakes, caused by emissions into the atmosphere of the Pechenganickel plant (Kola Peninsula) during the entire period of its operation. The technology of balanced identification is used, which allows, based on a mathematical description of heterogeneous geochemical processes occurring in ecosystems, to combine heterogeneous experimental data and build a computer model with an optimal balance of complexity and closeness to data. The results are presented and discussed, including estimates of the retrospective state of the simulated objects (before the start of intensive studies) and a forecast of their dynamics until 2030. According to model calculations, the intensity of Ni accumulation in soil was 2.4 and 2 times higher in bottom sediments during maximum precipitation periods (1980–2005), while according to the model forecast, after the shutdown of the plant, Ni accumulation in bottom sediments will begin to decrease and Ni will slowly leach from the soil with an intensity of 0.2 mg/m2 year.
LATE CAMBRIAN (~490 MA) ARC VOLCANIC ROCKS OF THE NORTH TIANSHAN OF KYRGYZSTAN: AGE CONSTRAINTS FROM U–Pb ZIRCON DATING
Authors: Alexeiev D. V. , Rojas-Agramonte Y. , Tretyakov А. А. , Gerdes A.
Published: April 2024

In the present contribution, we aim to determine the age of the oldest arc-related volcanic units in the North Tianshan of Kyrgyzstan (NTS) to better understand the early evolution of subduction systems in the western part of the Central Asian Orogenic Belt. We conducted zircon U–Pb dating (LA–ICP–MS) on andesitic tuffs from the Sultansary and Tashtambektor formations, which were previously believed to be of early Cambrian and middle Cambrian to early Ordovician age, respectively. Our results reveal age estimates of 491 ± 3 and 487 ± 3 Ma for these formations, indicating that both units are late Cambrian in age. The volcanic rocks belong to a major magmatic arc with a heterogeneous basement that evolved in the NTS during the late Cambrian and early Ordovician.
BAUXITES OF THE TATAR DEPOSIT (YENISEI RIDGE, RUSSIA): THE FIRST EVIDENCE OF CONTACT-KARST GENESIS
Authors: Boeva N. M. , Slukin A. D. , Makarova M. A. , Shipilova E. S. , Melnikov Ph. P. , Vnuchkov D. A. , Zhegallo E. A. , Zaitseva L. V. , Bortnikov N. S.
Published: April 2024

The Tatar bauxite deposit on the territory of the Russian Federation was formed as a result of sedimentation in contact-karst depressions of the products of denudation of lateritic weathering crusts of amphibolites. Detailed mineralogical studies of bauxites made it possible to reliably reconstruct the conditions for their formation. As it turned out parent rocks and weathered before rocks occurred due to the close location of the areas of nutrition and accumulation and denudation. At the same time, chemical processes was continuing in karst depressions. For the first time, the presence of nanoparticles of amorphous aluminum oxide was revealed into contact-karst bauxites. This characteristic feature of the form of alumina precipitation is associated with the subsequent cessation of lateritization processes and their attenuation with depth. The presence of amorphous aluminum monohydrate must be taken into account when choosing a scheme for bauxite enrichment.
FORMATION OF TRACHYTES FROM WANGTIAN’E VOLCANIC NECK OF THE CHANGBAISHAN AREA (NORTHEAST CHINA) AS A RESULT OF THOLEIITIC MAGMA CRYSTAL FRACTIONATION
Authors: Andreeva O. A. , Andreeva I. A. , Usoltseva A. I. , Yarmolyuk V. V. , Kovalchuk E. V. , Averin A. A. , Ji J.-Q. , Zhou X.
Published: April 2024

Tholeiitic basalts and trachytes of  Wangtian’e bimodal association are studied. It is shown that trachytes were formed under the leading role of crystal fractionation of the initial tholeiitic magma. Based on the method of melt and fluid inclusion studies, it was determined that hedenbergite phenocrysts from Wangtian’e volcanic neck crystallized in the temperature range of 1080–1100°С, and plagioclase phenocrysts crystallized at temperatures of 1050–1060°С. After thermometric experiments with melt inclusions in plagioclase from trachytes, in some cases relics of carbonates and carbon dioxide were observed in the inclusions. Trachyte phenocrysts contain hydrous Fe-rich silicate globules and CO2 inclusions containing carbonate phases. Fe-rich silicate globules are often intergrown with titanomagnetite and covered with films of amorphous carbon. A model the appearance of hydrous Fe-rich globules and CO2 inclusions with carbonate relics is proposed. It results due to the silicate-silicate and silicate-carbonate liquid immiscibility processes, that are caused by the evolution of the initial basaltic melt. As the trachyte melt has been risen to the surface, the ferrocarbonate liquid decomposed into magnetite, carbon, and carbon dioxide.
EXPERIMENTAL STUDY OF THE NON-MODAL PERTURBATION GROWTH MECHANISM IN A LAMINAR SUBMERGED JET
Authors: Ashurov D. A. , Vedeneev V. V. , Gareev L. R. , Ivanov O. O.
Published: April 2024

It is known that in wall-bounded flows, along with the growth of instability modes, the non-modal (algebraic) mechanism of linear growth plays an important role. In open flows, including submerged jets, the non-modal growth mechanism is theoretically studied only in the last decade; this mechanism has not yet been identified in experiments. In the present work, experiments on excitation of a non-modal “lift-up” growth mechanism are conducted. Special wavy structures (deflectors) are introduced into a laminar submerged jet of circular cross section, which excites a roller-like transverse movement. The data obtained unambiguously identify the non-modal “lift-up” growth of introduced disturbances. The development of perturbations in the experiment qualitatively corresponds to the theoretically calculated optimal perturbations. The features of the transition to turbulence caused by non-modal growth are considered.
THREE-TERM REPRESENTATIONS OF POWER TENSOR SERIES IN THE THEORY OF CONSTITUTIVE RELATIONS
Authors: Georgievskii D. V.
Published: April 2024

A class of power tensor series (constitutive relations) with coefficients (material functions), which are functions of three independent invariants, is considered in three-dimensional space. Based on the Hamilton–Cayley formula the exact expressions in the form of matrix series are found for the coefficients of three-term representations of such power series. The relationship of the coefficients of direct and inverse three-term constitutive relations is derived. The cases of tensor linearity, or quasi-linearity, as well as the independence of material functions from invariants are discussed.
THE EXACT SOLUTION OF THE WIENER–HOPF EQUATION ON THE SEGMENT FOR CONTACT PROBLEMS AND PROBLEMS OF THE THEORY OF CRACKS IN A LAYERED MEDIUM
Authors: Babeshko V. A. , Evdokimova O. V. , Babeshko O. M. , Zaretskaya M. V. , Evdokimov V. S.
Published: April 2024

This paper presents an approach that allows for the first time to construct an exact solution of the Wiener–Hopf integral equations on a finite segment for the case of meromorphic functions in Fourier transforms of the kernel. The Wiener–Hopf integral equation is traditionally considered set on a semi-infinite segment. However, in applications, there are often cases of their application specified on a finite segment. For these purposes, approximate methods of applying these integral equations have been developed. However, when considering the Wiener–Hopf integral equations generated by mixed problems of continuum mechanics and mathematical physics in a multilayer medium of finite thickness, it turned out that these integral equations are solved exactly both on semi-infinite and finite segments. The approach is based on a new modeling method in differential equations and in some types of integral equations. It allows the reduction of Wiener–Hopf integral equations to infinite systems of linear algebraic equations that are solved exactly. The obtained result opens up the possibility of constructing exact solutions to boundary value problems for deformable stamps and cracks of a new type in bounded bodies.
THE IMPACT OF THE WAVEFRONT ON A NONLINEAR WAVE IN A DISSIPATIVE MEDIUM
Authors: Bazylenko V. A. , Rudenko O. V.
Published: April 2024

Presented a method for generating solutions of the Burgers equation, which describe the interaction of waves in a nonlinear dissipative medium and a linearly growing wavefront. Exact solutions are used that describe these interactions, as well as the symmetry properties of the equation. It is shown that the rising wavefront is able to compete with dissipation and compress the signal in time. On the contrary, the wavefront with decreasing steepness “stretches” the signal.
DETONATION OF A COMBUSTIBLE GAS MIXTURE UPON THE INTERACTION OF A SHOCK WITH AN ELLIPSOIDAL INERT GAS BUBBLE
Authors: Georgievskiy P. Yu. , Sutyrin O. G.
Published: April 2024

Interaction of a shock wave in a combustible gas mixture with an ellipsoidal region of an inert gas of increased density is numerically simulated using the Euler equations in two-dimensional plane and axisymmetric formulations. Four qualitatively different regimes of indirect initiation of detonation have been found: upon reflection of a wave from the gas interface, upon focusing of secondary transverse shock waves on the axis/plane of symmetry, upon amplification of a transverse wave converging to the axis of symmetry, and upon secondary focusing of waves in front of the bubble. It is shown that the mode of detonation initiation significantly depends on both the intensity of the shock wave and the shape of the bubble. Based on a series of simulations, the dependence of the threshold Mach numbers of the incident wave on the shape of the bubble is determined. In the plane flow, a moderate elongation of the bubble leads to a significant decrease in the threshold Mach number. In an axisymmetric flow, the lower threshold Mach number is less sensitive to the shape of the bubble, and the most effective detonation initiation is carried out using a spherical bubble. The effect of shock wave focusing makes it possible to achieve successful initiation of detonation at a fundamentally lower intensity of the incident wave compared to direct initiation.
TURBULENT BOUNDARY LAYER ON A PERMEABLE PLATE IN SUPERSONIC FLOW WITH POSITIVE PRESSURE GRADIENT UNDER FOREIGN GAS INJECTION
Authors: Leontiev A. I. , Lushchik V. G. , Makarova M. S.
Published: April 2024

A numerical simulation of a turbulent boundary layer on a permeable plate with helium injection into a supersonic xenon flow in the presence of a positive longitudinal pressure gradient has been carried out. The injection regimes are considered, in which the temperature of the injected gas is lower than the temperature of the adiabatic impermeable wall and the stagnation temperature of the oncoming flow. The existence of a minimum temperature of the permeable wall is confirmed, at which the wall temperature is lower than the temperature of the injected gas, while there are two sections along the length of the permeable plate in which the adiabatic conditions are satisfied. The results of calculations of a supersonic flow with a longitudinal pressure gradient differ significantly from the results obtained for a gradientless flow around a plate, both for subcritical and critical injection.
PRESTRESSED MULTILAYER DESIGNS OF POLYMER COMPOSITES FOR THE VIBRATION AND NOISE CONTROL OF AIRCRAFTS
Authors: Karpov E. V. , Larichkin A. Yu. , Goverdovskiy V. N. , Brovkina Yu. I. , Prokhorov A. N.
Published: April 2024

This paper presents an approach for designing the compact and miniature infra- and low-frequency vibration isolation systems based on the layered composite elastic elements with adjustable negative and quasi-zero stiffness. New problems of modeling the specified parameters of stiffness and bearing capacity of the elements of a certain geometry under combined mode loading are solved by varying the structure, elasticity and configuration of the layers, and by controlling the local mobility of the binder. The approach is valid with the results of experimental designing and studying the system models. Application of the approach makes a qualitatively change in solving a number of critical issues of vibration and noise control in the aerospace and other promising engineering.
QUANTUM BLACK HOLES IN THE EXPANDING UNIVERSE
Authors: Neznamov V. P. , Safronov I. I. , Shemarulin V. Е.
Published: April 2024

In the expanding Universe, the evolution of quantum black holes with the modified Schwarzschild and Reissner–Nordström geometries is considered. All quantum black holes at definite moments of the cosmological time lose event horizons and are transformed to gravitating objects with masses M.
THREE-DIMENSIONAL SHELL MODEL FOR LAYER-BY-LAYER STUDY OF THE STRESS AND STRAIN STATE OF IRREGULAR CONICAL SANDWICH SHELLS
Authors: Bakulin V. N.
Published: April 2024

A methodology for constructing three-dimensional shell models for the layer-by-layer study of the stress and strain state of irregular sandwich shells, which are increasingly used in practice, is proposed. An original approach is considered for obtaining approximating displacement functions in the finite elements of the core layer, which does not lead to a discontinuity in the generalized displacements on the interfaces with moment skin layers. The development of such models makes it possible to significantly expand the class of problems to be solved and, with the necessary accuracy and degree of detail, for the first time to study the stress and strain state in the general case of irregular sandwich shells in a wide range of variation in the geometric and physical and mechanical characteristics of the layers. The possibilities of the proposed methodology are illustrated by the example of the study of the stress and strain state of conical sandwich shells with rectangular cutouts.
ANALYTICAL RELATIONSHIP BETWEEN THE COEFFICIENTS OF THE ADDED MASS AND THERMAL CONDUCTIVITY IN A SUSPENSION OF SPHERICAL PARTICLES
Authors: Boshenyatov В. V.
Published: April 2024

An analytical dependence between the dimensionless coefficients of the added mass and thermal conductivity was obtained in a suspension of spherical particles. The dependence is confirmed by comparison with the theoretical data of other authors, including at elevated concentrations of dispersed particles, taking into account their hydrodynamic interaction.
INFLUENCE OF THE DIRECTION OF SOURCES ON THE PHASE INVARIANTS OF VECTOR-SCALAR FIELDS IN A SHALLOW SEA
Authors: Kuznetsov G. N. , Stepanov A. N.
Published: April 2024

For the first time, the properties of the phase invariant of sound to vector-scalar fields formed in a waveguide by directional multipole sources are studied. It is shown that when even such complex sources are used, the phase invariant is valid for sound pressure and for projections of the vibrational velocity vector. It practically does not depend on the directivity and frequency of the source, the distance between the receiver and the source, and on the parameters of the waveguide.
ON THE ROLE OF COUPLING COEFFICIENT IN DYNAMIC PROBLEM OF THERMOELASTICITY WITH LOCALIZED INCLUSION
Authors: Morozov N. F. , Indeitsev D. A. , Muratikov K. L. , Vavilov D. S. , Kudryavtsev A. A.
Published: April 2024

In the present paper paper the dynamic problem of thermoelasticity with a localized inclusion in the medium is considered. It is shown that in the resonant regime an important role is played by the coupling coefficient of the temperature and strain fields. The coupling of the problem and the presence of a discrete spectrum lead to the appearance of an additional term in the expression for temperature, which is localized and does not describe the diffusion process.
A GAUGE-INVARIANT LAGRANGIAN DETERMINED BY THE n-POINT PROBABILITY DENSITY FUNCTION OF VORTICITY FIELD OF THE WAVE OPTICAL TURBULENCE
Authors: Grebenev V. N. , Grishkov A. N.
Published: April 2024

The geometry methods for Yang–Mills fields of the gauge transformations are applied to finding an invariant Lagrangian in fiber bundle of the configuration \(2d\) space \(X\) of the turbulent flow defined by the \(n\)-point probability density function \({{f}_{n}}\) (PDF). The two-dimensional wave optical turbulence is considered in the case of the inverse cascade of energy. The n-point PDF of the vorticity field satisfies the \({{f}_{n}}\)-equation from the Landgren–Monin–Novikov (LMN) hierarchy. The basic result reads: we construct the Lagrangian which is invariant under a subgroup \(H \subset G\) – the group of the gauge transformations in fiber bundles of the space X and the conserved currents.
DISTRIBUTION OF ELECTRIC FIELDS ON THE SURFACE OF INCLUSIONS IN MATRIX COMPOSITE
Authors: Kolesnikov V. I. , Yakovlev V. B. , Lavrov I. V. , Sychev A. P. , Bardushkin A. V.
Published: April 2024

Expressions are obtained for operators of concentration of electric field strength and displacement on the surface of inclusions in matrix composite depending on shape and volume fraction of inclusions in material. These operators relate the fields on the inclusion surface on the matrix side with the average values of the electric field strength and displacement in the composite sample.
EXACT SOLUTIONS TO INHOMOGENEOUS BOUNDARY VALUE PROBLEMS OF THE THEORY OF ELASTICITY IN A RECTANGLE
Authors: Kovalenko M. D. , Kerzhaev A. P. , Menshova I. V. , Karnet Yu. N.
Published: April 2024

A method is proposed for constructing exact solutions to boundary value problems of the theory of elasticity in a rectangle with stiffeners located inside the region (an inhomogeneous problem). The solutions are represented by series in Papkovich–Fadle eigenfunctions, the coefficients of which are determined explicitly. The method is based on the Papkovich orthogonality relation and the theory of expansions in Papkovich–Fadle eigenfunctions developed by the authors in homogeneous boundary value problems of the theory of elasticity in a rectangle (the biharmonic problem). The solution sequence is demonstrated with the example of an even-symmetric problem for a rectangle the sides of which are free, and an external load acts along the stiffener located on the axis of symmetry of the rectangle.
ANALYTICAL SOLUTION OF THE CREEP PROBLEM VISCOELASTIC MATERIAL IN A ROUND TUBE
Authors: Kovtanyuk L. V.
Published: April 2024

Using a mathematical model of large deformations of materials with elastic, plastic and viscous properties, an analytical solution was obtained for deformation under creep conditions of a bung in a round tube with a varying pressure drop. The motion is considered taking into account the sliding of the material in the vicinity of the rigid wall of the pipe and its deformation under increasing, constant and decreasing pressure. Displacements, reversible and irreversible deformations, stresses at all stages of deformation, including residual deformations and stresses at full unloading are calculated.
INTERACTION OF 2-AMINO-(4-ARYL)-SUBSTITUTED THIA- AND OXAZOLES WITH 5-CYANO-1,2,4-TRIAZINES
Authors: Krinochkin A. P. , Rammohan A. , Shtaitz Ya. K. , Kopchuk D. S. , Ladin E. D. , Sharafieva E. R. , Taniya O. S. , Zyryanov G. V. , Matern A. I. , Chupakhin O. N.
Published: April 2024

An interaction of 6-aryl-1,2,4-triazine-5-carbonitriles with 2‑amino-substituted thiazoles and oxazoles has been studied. The difference in the reactivity of these aminoheterocycles depending on the presence of an oxygen or sulfur atom in their composition has been demonstrated. Previously, the 4-aryl-3-hydroxy-2,2'-bipyridines were obtained as products of aza-Diels–Alder reaction between 6-aryl-3-(2-pyridyl)-1,2,4-triazine-5-carbonitriles and 2-amino-4-aryloxazoles. In the present work we have shown that the reaction of 6-aryl-1,2,4-triazine-5-carbonitriles with 2-aminothiazoles led to the products of ipso-substitution of cyano-group. The aza-Diels–Alder reaction of these compounds with 2,5-norbornadiene allowed to obtain (2,2'-bi)pyridines with the thiazol-2-amine moiety at alpha-position.
DIPINODIAZAFLUORENES AS REAGENTS FOR SELECTIVE EXTRACTION OF PALLADIUM, GOLD AND RUTHENIUM
Authors: Zubricheva D. V. , Vasilyev E. S. , Bizyaev S. N. , Tikhova V. D. , Tkachev A. V.
Published: April 2024

Dipinodiazafluorenes are hybrid nopinane-annelated heterocycles whose molecules include a heterocyclic core of 4,5-diazafluorene condensed with fragments of terpene hydrocarbon, capable of selectively extracting palladium (88−100%), gold (42−96%) and ruthenium (8−19%) by single extraction from acidic aqueous solutions (pH 1.2) containing complex mixtures of 3d-elements and precious metals.
SYNTHESIS OF HYDROGENATED MESO-TETRAPYRIDYLPORPHYRINS WITH A CONTROLLED COMPOSITION
Authors: Lyubimtsev A. V. , Semeikin A. S. , Koifman M. O. , Koifman O. I.
Published: April 2024

The work is devoted to the development of a method for obtaining a highly sensitive composition of a controlled composition containing cationic water-soluble 5,10,15,20-tetrakis(N-Me-pyridin-3-yl)chlorine and 5,10,15,20-tetrakis(N-Me-pyridin-3-yl)bacteriochlorin. The process of diimide reduction of 5,10,15,20-tetrakis(pyridin-3-yl)porphine in pyridine and in the absence of a solvent has been studied. It is shown that the reduction in the alloy significantly reduces the reaction time (from 12 to 1.5 h) and allows to obtain compositions with a yield of up to 90%.
AN EFFICIENT APPROACH FOR THE PREPARATION OF FLAME-RETARDANT NANOCOMPOSITE POLYMERIC MATERIALS BASED ON HIGH-DENSITY POLYETHYLENE AND MAGNESIUM HYDROXIDE
Authors: Аrzhakova О. V. , Dolgova А. А. , Kopnov А. Yu. , Yarusheva А. Yu. , Volynskii A. L.
Published: April 2024

A novel approach for the development of nanocomposite materials based on high-density polyethylene and an inorganic flame retardant, magnesium hydroxide, via the fundamental strategy of environmental crazing of polymers has been advanced. Efficient methods for incorporation of magnesium nitrate as a precursor into mеsoporous polymeric matrixes have been proposed, and the optimal conditions providing high-conversion in situ hydrolysis of magnesium salt to magnesium hydroxide within the confined space of mesopores of polymeric matrixes have been found. As a result of in situ hydrolysis, spherical or needle-like nanoparticles of magnesium hydroxide are found to be uniformly distributed within the volume of the high-density polyethylene matrix. The resultant nanocomposite polymeric materials with the low content of nanoparticles of magnesium hydroxide (below 30 wt. %) are characterized by reduced flammability and mechanical characteristics that are comparable to those of the initial polymer.
PHASE FORMATION IN THE Mg3 – nNinBPO7 SYSTEM
Authors: Smirnova M. N. , Kop’eva M. A. , Nipan G. D. , Nikiforova G. E. , Yapryntsev A. D. , Arkhipenko A. A.
Published: April 2024

Samples of Mg3 – nNinBPO7 (n = 0–3), synthesized by gel combustion followed by annealing at 980°C and cooled in the inertial-thermal mode, were studied by X‑ray powder diffraction, infrared spectroscopy, and X-ray fluorescence spectrometry. For the first time, the crystalline phase of Ni3BPO7 with the β-Zn3BPO7 structure has been experimentally obtained. When the composition of the samples changed from Mg3BPO7 to Ni3BPO7, a region of coexistence of α‑Mg3BPO7 and β-Ni3BPO7 phases was found. An analysis of the diffuse reflectance spectra of the Mg1.5Ni1.5BPO7 sample showed the presence of Ni2+ cations in an arrangement not symmetric octahedral or tetrahedral.
THE TWO-STAGED REDUCTION SELECTIVE NON-CATALYTIC REDUCTION PROCESS OF NITROGEN OXIDES INTHERMAL GENERATION UNIT FLUE GASES
Authors: Kulish O. N. , Zaporozhskii K. I. , Orlova M. N.
Published: April 2024

The basic concern of research presented in the article was a development of selective non-catalytic reduction of nitrogen oxides in thermal generation units flue gases. The results of the experiments of two-staged selective non-catalytic reduction of nitrogen oxides with below-stoichiometric urea injection are described. Higher and more stable reducing efficiency with minimal formation of ammonia in treated gases is showed.
A NEW QUANTITATIVE METHOD OF EXPRESS ANALYSIS OF NATURAL RUBBER DIRECTLY IN THE ROOT OF THE RUBBER PLANT BY THE SPIN PROBE EPR METHOD
Authors: Martirosyan L. Yu. , Goldberg V. M. , Barashkova I. I. , Kasparov V. V. , Martirosyan Yu. Ts. , Motyakin M. V. , Gaydamaka S. N. , Varfolomeev S. D.
Published: April 2024

In this work, the phenomenon of selective sorption of a stable nitroxyl radical TEMPO on rubber particles in the powder of dried and dispersed root of kok-sagyz was discovered. This feature of the rubber-bearing root material contributed to the development of a new, highly sensitive method of quantitative analysis of rubber by the integral intensity of the EPR TEMPO signal. The main advantages of the proposed method are the speed and the ability to determine the content of rubber directly in the roots of the plant in microquantities (5–30 mg).
ESTIMATION OF EFFICIENCY OF OXALIC ACID APPLICATION IN SOLUTION COMBUSTION SYNTHESIS OF CATALYST FOR PRODUCTION OF HYDROGEN AND CARBON FROM METHANE
Authors: Kurmashov P. B. , Popov M. V. , Brester A. E. , Ukhina A. V. , Bannov A. G.
Published: April 2024

In this work, the parameters of catalyst synthesis by solution combustion method using oxalic acid as a reducing agent, were investigated. The catalysts activity in the process of obtaining hydrogen and carbon nanofibers by the catalytic decomposition of methane has been determined. The effectiveness of using this reagent for the preparation of a nickel catalyst (90% Ni/10% Al2O3) that does not require preliminary reduction with hydrogen was shown. Based on the regression analysis, it was found that among the catalyst synthesis parameters, the yields of carbon and hydrogen are most strongly influenced by temperature.
C(2)H-ALKYLATION OF (BENZ)OXAZOLES WITH TERTIARY ALKYL CHLORIDES AND BROMIDES UNDER PHOTOINDUCED PALLADIUM CATALYSIS
Authors: Lavrentev I. V. , Astakhov A. V. , Shepelenko K. E. , Chernyshev V. M.
Published: April 2024

A method for selective C(2)H alkylation of (benz)oxazoles with tertiary alkyl chlorides and alkyl bromides under photoinduced by visible light (460 nm) catalysis with Pd(PPh3)4/[Bu4N]I system in N,N-dimethylacetamide has been developed. Tetraalkylammonium salt has a significant promoting effect on the reaction which seems to be based on the stabilization of nanosized palladium species in the catalytic system.
ACTIVATING EFFECT OF AlCl3 IN HOMO-COUPLING REACTION OF ACETYLENE COMPOUNDS UNDER THE ACTION OF Mg–Cp2ZrCl2 REAGENT SYSTEMS
Authors: Ramazanov I. R. , Sadykova F. T. , Zosim T. P. , Frolova K. S. , Dzhemilev U. M.
Published: April 2024

The activating effect of AlCl3 in the amount of 10 mol. % in the homo-coupling of alkyl-, phenyl-, and silyl-substituted acetylenes with the Mg–Cp2ZrCl2 reagent system was found for the first time. The unique nature of this activation is indicated by the fact that in the presence of 10 mol. % of Lewis acids such as BF3 ⋅ Et2O, Me3SiCl, InCl3, and SnCl4, the reaction with 5-decyne does not occur even after 5 h, while in the presence of AlCl3, homocoupling products are selectively formed in high yield in 10 min at room temperature.
AQUEOUS-PHASE HYDROGENATION OF FURFURAL IN THE PRESENCE OF SUPPORTED METALLIC CATALYSTS OF DIFFERENT TYPES. A REVIEW
Authors: Mironenko R. M. , Belskaya O. B. , Likholobov V. A.
Published: April 2024

Hydrogenation of furfural in the presence of heterogeneous catalysts has recently attracted increased interest as a method for the synthesis of oxygen-containing compounds of various classes based on renewable raw materials. The composition of the catalyst and the conditions of its preparation essentially determine which of the routes of reductive conversions during the hydrogenation of furfural will be predominant. The present review summarizes and analyzes methods for controlling the physicochemical and functional properties of various metal catalysts with an emphasis on Pd-, Ni-, Co, and Cu-containing catalytic compositions, as the most common and practically significant in the hydrogenation of furfural. Many examples show the influence of the nature of the support, the composition of the active metal precursor, and the conditions for the formation of metal nanoparticles on the activity and selectivity of supported catalysts in the reductive conversions of furfural under aqueous-phase hydrogenation conditions. Promising directions of research on the development of methods for the synthesis of efficient catalysts with controlled functional properties in the hydrogenation of furfural are considered. The bibliography includes 127 references.
SYNTHESIS OF DEUTERIUM-LABELED SALICYLCARNOSINE
Authors: Shevchenko V. P. , Nagaev I. Yu. , Kulikova O. I. , Myasoedov N. F.
Published: April 2024

The effect of temperature on the effectiveness of the introduction of deuterium into a new biologically active compound salicylcarnosine (SC) has been studied. Deuterium gas and heavy water were used as a source of deuterium. The synthesis of labeled SC by the solid-phase method at 190°C leads to the production of [D]SC with a yield of 53%, and a deuterium content of about 4.8 atoms per molecule. During isotope exchange with deuterated water, it was shown that after pretreatment of the catalyst at room temperature with deuterium gas, isotope exchange between SC protons and deuterated water occurs more efficiently. [D]SC is formed with a yield of 46% and contains about 7.3 deuterium atoms per molecule. During the preparative synthesis of labeled SC according to this technique at 190°C, the yield of [D]SC was 60–70%, with a deuterium content of about 6.2 atoms per molecule. A new technique for activating the inclusion of deuterium in peptides opens up additional opportunities for obtaining highly labelled drugs.
SYNTHESIS AND STRUCTURE OF NEW [5]FERROCENOPHANE
Authors: Medved’ko A. V. , Churakov A. V. , Krut’ko D. P. , Vatsadze S. Z.
Published: April 2024

The first example of intramolecular diastereoselective domino reaction of ferrocene 1,1'-bis-enone to [5]ferrocenophane initiated with sodium ethylate was found. The product is [5]ferrocenophane with two pyridyl and one ethoxy substituents arranged asymmetrically in five carbon bridge. Diffraction studies showed that ferrocene is in almost ideal eclipsed conformation. The fan conformation found in the crystal is also preserved in solution, which was determined by NMR spectroscopy.
A NEW APPROACH TO THE SYNTHESIS OF HIGHLY DISPERSED DOUBLE LITHIUM-NICKEL AND DOUBLE LITHIUM-COBALT PHOSPHATES WITH THE DESIGNED PARTICLE MORPHOLOGY
Authors: Zharov N. V. , Maslova M. V. , Nikolaev A. I.
Published: April 2024

The paper presents a new low-temperature method for the synthesis of highly dispersed powders of double phosphates LiCoPO4 and LiNiPO4 using low-waste technology. It has been shown that the morphology and particle size of the obtained materials depend on the type of initial precursors. The obtained compounds are characterized by elemental, XRD, SEM, cyclic volammetry, cyclic chronopotentiometry analyses. A new approach to the synthesis of submicron powders of lithium double phosphates and transition metal (nickel, cobalt) is more effective compared to current methods.
WAYS TO REDUCE CO2 EMISSIONS AT THE CONVERSION OF NATURAL GAS INTO CHEMICAL PRODUCTS
Authors: Arutyunov V. S. , Nikitin A. V. , Savchenko V. I. , Sedov I. V.
Published: April 2024

One of the most realistic possibilities for reducing anthropogenic carbon dioxide emissions is its involvement as a feedstock in various processes for producing gas chemical products. First of all, it is advisable in the production of the largest-tonnage products, such as syngas, hydrogen and methanol. The paper considers the possibility of involving carbon dioxide in non-catalytic autothermal processes of the production of these products. A combined process for the production of methanol and hydrogen without CO2 emission based on the matrix conversion of natural gas into syngas is presented.
A NEW MULTIFUNCTIONAL LUBRICANT ADDITIVE BASED ON A SULFUR-CONTAINING DERIVATIVE OF 2,6-DIMETHYLPHENOL
Authors: Bordubanova E. G. , Oganesova E. Yu. , Lyadov A. S. , Parenago O. P.
Published: April 2024

New dialkyldithio derivatives of 2,6-dimethylphenol have been synthesized and characterized. For the first time, the polyfunctional properties of these compounds have been studied as additives to lubricating oils in the processes of friction and wear in the boundary friction regime, as inhibitors of high-temperature oxidation of hydrocarbons, and as protectors of metal surfaces. It has been established that already with the content of synthesized additives in lubricating oils in the amount of 0.5 wt. % antiwear properties are improved more than twice. It has been shown that additives exhibit a complex antioxidant effect and high efficiency at all stages of the oxidation process, and even at ultra-low concentrations (0.005 wt. %), their ability to resist oxidation exceeds widely used analogs. New additives are of considerable interest to modern lubrication science, and they can be used in motor oil compositions and other lubricants.
SINGLE-ATOM ALLOY Pd1Ag6/Al2O3 EGG-SHELL CATALYST FOR SELECTIVE ACETYLENE HYDROGENATION
Authors: Mashkovsky I. S. , Melnikov D. P. , Markov P. V. , Baeva G. N. , Smirnova N. S. , Bragina G. O. , Stakheev A. Yu.
Published: April 2024

In this work, a single-atom alloy Pd1Ag6/Al2O3 catalyst for the selective hydrogenation of acetylene was obtained with an egg-shell distribution of the active phase over the catalyst granules. The formation of an egg-shell structure was confirmed by electron probe microanalysis. It was found that metals are predominantly localized at a depth of 130–160 µm from the surface of the granules. Transmission electron microscopy and X-ray photoelectron spectroscopy have revealed the formation of a substitutional PdAg solid solution with electron density transfer from Ag to Pd. The formation of Pd1 single sites was confirmed by FTIR spectro-scopy of adsorbed CO. In the selective hydrogenation of acetylene the synthesized single-atom alloy Pd1Ag6/Al2O3 with egg-shell distribution showed high selectivity, which radically exceeds the selectivity of the palladium counterpart.
COMPOSITE MATERIALS BASED ON MOF ZIF-8 AND IONIC LIQUID [BMIm]+[BF4]−: AN EPR STUDY USING NITROXIDE SPIN PROBES
Authors: Kudryavyh N. А. , Ivanov М. Yu. , Poryvaev А. S. , Polyukhov D. М. , Sagdeev R. Z. , Fedin М. V.
Published: April 2024

A method for the controlled filling of pores in metal-organic frameworks (MOFs) with ionic liquids (ILs) is proposed, which can be applied for selective gas sorption in MOFs. Using an example of MOF ZIF-8 and IL [BMIm]+[BF4]−, the composites with different IL content were prepared upon control by electron paramagnetic resonance (EPR) of nitroxide spin probes. The effect of IL on the sorption of nitric oxide (II) into these composites was studied using inversion gas chromatography.
STOCHASTIC MODELING THE TRANSPORT COEFFICIENTS OF LIQUIDS
Authors: Rudyak V. Ya. , Lezhnev E. V.
Published: April 2024

A method of stochastic molecular modeling (SMM) of liquid transport coefficients has been developed. They are calculated using fluctuation-dissipation theorems, but unlike the molecular dynamics (MD) method, the phase trajectories of the system are simulated stochastically. The force acting on the molecule is determined stochastically using the created database of intermolecular forces. The effectiveness of the method is demonstrated by the example of calculating transport coefficients. It is shown that the SMM method requires much less computational resources than the MD method.
NONSTATIONARY VENTTSEL PROBLEM WITH VMOx LEADING COEFFICIENTS
Authors: Apushkinskaya D. E. , Nazarov A. I. , Palagachev D. K. , Softova L. G.
Published: April 2024

We obtain some new results on strong solvability in the Sobolev spaces of the linear Venttsel initial-boundary value problems to parabolic equations with discontinuous leading coefficients.