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Abstract: The paper presents the experimental results of the electrical resistance, magnetic susceptibility, and Hall effect of the intermetallic compounds of the Gd−In system in a wide temperature range. The normal and anomalous Hall effect is determined as well as the electronic band parameters and the effective parameter of the spin-orbit interaction of the described intermetallic compounds. PubDate: 2022-07-26

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Abstract: Using X-ray diffraction analysis, the effect of Ar+ ions with an energy of 15−20 keV (at ion current densities of 100−300 μA/cm2) on the microstructure, the level of internal microstresses and the texture of cold rolled ribbons of alloy Ni – 13.9 wt.% W is studied. It is found out that short-term irradiation of 80 μm thick ribbons with a fluence of 3.1·1016 cm–2 (for 50 s) at temperatures T ≤ 370°C and T = 630°C leads to a decrease in microstresses in their entire volume, while the original texture is retained. With an increase in the fluence to 9.7·1017 cm–2 at T = 630°C, the texture changes from (220) to (200). Changes in microstresses and texture on the irradiated and non-irradiated sides of 80-μm-thick ribbons are comparable to each other, despite the fact that the projected range of Ar+ ions with an energy of 15−20 keV in the alloy is only ~7 nm. It is known that annealing of such ribbons in an oven (700°C, 30 min) does not cause their recrystallization. At 850°C, the microstresses are relieved and the texture dramatically changes from (220) to (200) both as a result of annealing in a furnace (15 s) and as a result of irradiation with a fluence of 3.2·1016 cm–2 for 17 s, but the effect of stress removal in the course of furnace annealing is 3 times lower than that of irradiation. Thus, the following facts have been established: 1) the occurrence of recrystallization processes in the alloy under study during irradiation at a temperature lower than the temperature of the onset of thermally activated recrystallization and 2) a higher rate of microstress drop (and to lower values) in the course of irradiation than during furnace annealing. This indicates a significant role of nanoscale radiation-dynamic effects at the cascade-forming irradiation of metastable media. PubDate: 2022-07-26

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Abstract: The problem of motion of the helium atom inside the fullerene molecule at ultralow temperatures is considered. The solution of the Schrödinger equation is obtained by numerical methods using special functions. The potential energy of interaction of the fullerene particle with the helium atom is calculated by integrating the modified Lennard–Jones potential over the idealized surface of the hollow nanoparticle. As a result of calculations, zones of the most probable localization of the atomic particle in the states with (n, m, and kn) inside the C60 fullerene were determined and visualized. PubDate: 2022-07-26

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Abstract: In this study, the bound state solution of the modified Schrödinger equation is found for the new supposed combined Hultén and Yukawa-class potentials. Analytical expressions for the energy eigenvalue and the corresponding radial wave functions are obtained for arbitrary orbital quantum number l ≠ 0 . The eigenfunctions obtained are expressed in terms of hypergeometric functions. It is shown that the energy levels and the eigenfunctions are susceptible to the potential parameters. The energy eigenvalues and the corresponding radial wave functions are determined for several special cases. PubDate: 2022-07-26

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Abstract: The propagation of an extremely short optical pulse is analyzed based on a numerical solution of the Maxwell equation for a dilaton field in a flat space-time. The dynamics of the pulse turned out to be unstable and the pulse collapsed. The influence of the Lagrangian parameter α is analyzed in cases of the Einstein–Maxwell scalar theory, low-energy action of string theory, and the Kaluza–Klein field equations obtained by dimensional reduction of the Einstein five-dimensional theory. PubDate: 2022-07-25

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Abstract: The paper investigates physical properties of a pulsed arc discharge of low (≈1 Pa) pressure created in argon by a plasma source with the thermionic and hollow cathodes. It is shown that the pulsed discharge is initiated in the extended hollow anode at a higher arcing voltage ranging between 100 and 300 V, thereby providing the current up to 800 А with the peak power of several tens of kilowatts. The growth in the arcing voltage leads to a reduced distribution heterogeneity of the plasma concentration by more than one order of magnitude throughout the hollow anode height. The axial magnetic field increased by the higher current in the magnetic coil leads to an increase in the non-self-sustained arc discharge at a higher arcing voltage. PubDate: 2022-07-25

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Abstract: The aim of this work is to analyze the structure and properties of a coating of the SnO2–In2O3–Ag–N composition formed on copper by a complex method combining electroexplosive spraying, irradiation with a pulsed electron beam, followed by nitriding in the plasma of a low-pressure gas discharge. It is shown that the thickness of the coating is ≈100 μm. The wear resistance of a coated copper specimen exceeds that of uncoated copper by a factor of 2.8. The friction coefficient of the coated specimens is μ = 0.479, which is a factor of 1.4 lower than that of uncoated copper μ = 0.679 ± 0.048. It is found out that hardness of the coating increases closer to the substrate and reaches a maximum value of ≈ 1400 ± 98 MPa (the substrate hardness is 1270 MPa). According to the micro X-ray spectral analysis, the main chemical element of the coating is silver; copper, tin, indium, oxygen and nitrogen are present in much smaller amounts. It is revealed by the XRD analysis that the main phases of the coating are copper- and silver-based solid solutions. PubDate: 2022-07-25

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Abstract: We present a description of the application “SDVEApp” designed to conduct research on the dynamic evolution of near-Earth space objects, namely, for calculation and visualization of the near-Earth object characteristics frequently used in research. In addition, the application makes it easier to work with a number of well-known catalogs of space objects. We demonstrate the results of application of the developed software to a set of objects from the NORAD and ESA “Classification of geosynchronous objects” catalogs, as well as objects, data on which were obtained from observations made by the employees of the Department of Celestial Mechanics and Astrometry of the Research Institute of PMM TSU. PubDate: 2022-07-25

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Abstract: Cosmological model describing the Universe without the singularity and without the Beginning, that is, the eternal Universe evolving from the infinite past, is proposed. The main component of the model is the nonlinear Dirac spinor field with the power-type nonlinearity \( {\left(\overline{\uppsi}\uppsi \right)}^n. \) This field determines the evolution of the Universe so that the Universe always exists. PubDate: 2022-07-25

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Abstract: The results of a study of the dislocation structure evolution in polycrystals of homogeneous solid solutions in low-stability states in Cu-Mn-based alloys with FCC crystal lattice are presented. It is found out that each stage is characterized by its own deformation carrier in the form of a certain dislocation substructure (DSS), whose volume fraction has a maximum in this stage. At the same time, the deformation carrier of the previous stage gradually disappears as the strain degree (ε) increases in the current stage, and there appears a deformation carrier of the subsequent stage. In a certain range of ε values, the deformation carriers characteristic of the previous, current and subsequent stages coexist. It is shown that there are transitions from some types of DSS to other types in certain strain degree ε intervals. It is revealed that each deformation stage has its own DSS – deformation carriers. The stage-to-stage transition is accompanied by the formation of new deformation carriers, which is a characteristic feature of low-stability states of the system. Logically, this situation is observed because the study is carried out at a grain size involving a possibility of implementing a low-stability structural-phase state of the alloy, since in this case the grain size acts as a kind of a governing parameter. PubDate: 2022-07-25

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Abstract: The paper presents the results of studies of thermal conductivity, structure, and physico-chemical properties of samples of polymer composite material based on thermosetting phenol-formaldehyde resin and hexagonal boron nitride. It was found that with an increase in the volume fraction of boron nitride from 5 to 85%, the effective thermal conductivity coefficient at 300 K increased from 0.63 to 18.5 W/m·K. Experimental results were compared with the data calculated using known theoretical models used to describe the process of thermal conductivity in polymer composite materials. PubDate: 2022-07-25

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Abstract: Regular features of the generation of gas-discharge beam-plasma formations formed in a high-current non-self-sustained glow discharge at low (≈1 Pa) pressure in an extended, 1.2 m long, hollow cathode with a volume of 0.34 m3 with a length-to-diameter ratio of 2: 1 are investigated. It is shown that in a system with one electron source providing injection of electrons into the hollow cathode of a glow discharge, a sharp nonuniformity (≈40%) of the nitrogen plasma concentration distribution is observed. In an extended hollow cathode, the problem of inhomogeneity of the plasma concentration distribution is solved by using two electron sources, which provides an injection of electrons from the auxiliary arc plasma into the hollow cathode of the glow discharge. The use of two electron sources makes it possible to form beam-plasma formations with an inhomogeneity of no more than 18%. A source of beam-plasma formations based on a non-self-sustained glow discharge with an extended hollow cathode is used for ion-plasma treatment of Cr12MoV die steel products. PubDate: 2022-07-25

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Abstract: A method for calculating bound states of the helium atom is proposed based on searching for roots of the Jost function for the process of electron scattering by a singly ionized helium ion. The differential equation for the Jost functions is obtained. PubDate: 2022-07-25

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Abstract: A thermodynamic analysis of the nucleation of bulk nanobubbles (BNBs) in a supersaturated aqueous solution has been carried out. In the model of a charged BNB with a double electric layer (DEL), the minimum work of formation and the radius of critical nuclei are calculated. Simple analytical expressions are derived, under which the BNB does not dissolve in water, i.e. is stable. For the first time, the authors succeeded in explaining the mystery of the long lifetimes of BNBs. PubDate: 2022-07-25

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Abstract: The inability of statistical mechanics to determine the bounds of the condensed medium phase regions, to compute the thermodynamic coordinates of phase transitions, to predict the molecular structures astride of the phase transition points, to estimate the rates of transitions from nonequilibrium to equilibrium, to determine the dependence of the solid body structure on the rate of liquid melt cooling, etc. is one of the most chronic diseases of modern theory. All these defects are related to the fundamental problem of unification of the laws acting in microcosm and macrocosm. It is indisputable that these laws describe the same, i.e., material systems of many interacting particles. Therefore, a general law must exist which combines both levels of description of matter into a comprehensive whole. Mechanics itself does not contain the collective properties of many-particle systems, but, following general logic, the signature of these properties should take place in the laws which govern the microscopic behavior of the system elements. The feedback principle pretends to accomplish such unification without any violation of the principles which underlie statistical mechanics. PubDate: 2022-07-25

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Abstract: The study of the absolute line intensities in the high-resolution spectrum of the D234S molecule in the range of 2300–2900 cm–1 has been carried out for the first time. As a result of our analysis, about 800 experimental intensities of vibrational-rotational transitions have been obtained for the v1 + v2 and v2 + v3 bands, and a set of 6 parameters of the effective dipole moment has been calculated, which reproduce the initial experimental line intensities with standard deviation drms = 9.7%. A list of transitions with frequencies and line intensities in the range under study has been compiled. PubDate: 2022-07-25

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Abstract: The article is focused on statistical properties of spatial distribution of galaxies in the Universe on scales exceeding 5 Мpc. The investigation aims at finding an appropriate algorithm for modeling random realizations of ensembles. The objects of research are the statistical properties of the spatial distribution of galaxies on scales exceeding 5 Mpc. The aim of the study is to find a suitable algorithm for modeling random realizations of the statistical ensemble of such distributions, which makes it possible to move to remote regions of large scales with depleted statistics, and on the constructed model to test signs of the transition from correlated to uncorrelated (if any) regions of the Universe. Information about such a boundary, called in the work the horizon of independence, is a necessary component of the modern model of the world in the era of extraatmospheric astronomy. The need to determine it is dictated not only by the natural desire to look beyond the horizon, but also by the reliance on mutually distant parts of the Universe within the framework of this model practiced in observational astronomy, as independent realizations of one statistical ensemble, ensuring the representativeness of the sample. The research method is based on the use of the Uchaikin–Zolotarev power spectrum approximation and the Markov chain constructed on its basis. A comparison with observational data demonstrates a high flexibility of the approximation and its potential effectiveness in solving the problem of the independence horizon. PubDate: 2022-07-25

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Abstract: The physical and chemical processes occurring in non-metallic inorganic porous coatings during the passage of a high-voltage alternating sinusoidal current through the coated metal conductors are investigated by the method of mathematical modeling. The compositions of electrolytes and the modes of coating formation are developed, and their characteristics are determined. A wet coating case is considered. It is found out that at a high voltage in liquid-filled pores there are fast electrode reactions, reducing the number of charge carriers in the liquid and increasing the voltage drop in the oxide layer. The simulation results show a theoretical possibility of an 80% suppression of the corona discharge. In practice, when an electric current with a voltage of up to 75 kV passes through the 5.5 mm-diameter wires, the proposed coatings reduce the power losses on the corona discharge by 20% and increase the corona discharge voltage on the wires by 3 kV. PubDate: 2022-07-25

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Abstract: The quantum states of the Kapitza pendulum are investigated within the framework of the effective potential obtained by the method of averaging over fast oscillations. An analytical estimate of the energy spectrum of stabilized states is given using a model potential. For the lowest states of an inverted pendulum, an expression is obtained for the spectrum in terms of energies of a harmonic oscillator corrected using perturbation theory. Tunneling effect corrections to the energies of resonance states in two wells of the effective potential are found. The results of calculations of the structure of vibrational and rotational spectra of the Kapitza pendulum by the semiclassical method and by the Numerov numerical algorithm are compared. PubDate: 2022-05-01