The operating regimes of ion sources with a magnetically isolated discharge under conditions of packet-pulse power are experimentally studied. Ion sources with the magnetically isolated discharge are widely used in portable pulsed neutron generators in equipment for geophysical exploration of wells. The efficiency and performance of the logging equipment is largely determined by the amplitude–time characteristics of neutron fluxes, which depend on the magnetic field, anode voltage pulses, composition, and gas pressure. Post-discharge processes occurring in pauses between supply voltage pulses in the interelectrode gap affect the conditions for the re-ignition of the discharge and the stability of the characteristics of the generated electron flows. The results obtained show that gaps in the operation of the ion source occur in the initial part of the pulse packet. At the same time, their number increases with a decrease in the discharge current. The pulses of ion flows at the first actuations of the cell have a shorter duration due to the prolongation of the discharge formation processes.

   The sputtering of metal atoms in a corona discharge on the surface of silver is considered. When an electron moves in a medium, charge screening occurs with a delay in space and time, which leads to the emergence of a wake potential. The excited oscillations of the wake charge lead to the appearance of additional forces. The energy loss of the moving particle per unit path length is determined by the work produced by the deceleration force that is induced by the wake potential and acts on the particle in the medium. The effect of the wake potential on the ions (atoms) of the lattice matrix is analyzed. A well-known expression is used for the wake potential excited by a charged particle moving with an energy exceeding the Fermi energy. An expression for the sputtering cross section of metal atoms under the action of the wake potential excited by the electron beam is obtained. It is shown that the result of sputtering does not depend on the charge sign of the incident particle (electron or ion). The sputtering coefficient for the corona discharge on the silver surface is estimated.

   The thermal conductivity of exfoliated vermiculite has been estimated within the porous body model called in this work the model of multilayer wall with jumpers. The properties of a solid frame (matrix) of this wall are taken from the preliminary experiments on the chemical composition (X-ray methods), porous structure (mercury porometry), thermal conductivity (stationary method and hot wire method), and absorption coefficient (infrared Fourier spectroscopy). The thermal conductivity of the solid matrix has been calculated using more than 20 existing algorithms. The problem of complex heat exchange under the stationary conditions of local thermodynamic equilibrium from 470 to 1270 K has been formulated and solved within the model of multilayer wall with jumpers. The one-dimensional case with closed rectangular parallelepiped pores and smooth walls. Pores are filled with dry air at atmospheric pressure. The method of the calculation of the stationary thermal radiation flux density inside the porous body with effective absorption, reflection, and transmission coefficients has been described. Radiation is considered as noncoherent, unpolarized, and isotropic. The method of the calculation of the thermal conductivity is presented and results are compared to experimental values of the thermal conductivity. It is assumed that the proposed method can be applicable to other porous inorganic bodies.

   The Coulomb law and the Newton’s gravity law define the forces acting between two electric or gravity charges, separated by a macroscopic distance and resting or moving slowly relative to each other. Quantum electrodynamics, in contrary, describes precisely what happens when two elementary charges (electrons) moving at high velocities close to the speed of light interact at a microscopic distance. Actually, the two theories describe two oppositely different extreme cases. However, it is commonly accepted that classical forces can be derived from quantum theory in the limit when the Plank constant tends to zero, though to trace this transition explicitly is technically rather difficult. The current note contains some estimations and speculations, pointing out the fact that quantum uncertainty somehow correlates with classical Coulomb and Newton laws, and this correlation does not require zero Planck constant. These estimations will probably be interesting to theoreticians and useful for teachers, who have to answer questions concerning correlations between classical and quantum approaches.

   A differential equation is obtained in an explicit form for a system of 2n vortices of intensity Γ lying on a straight line and one vortex of the intensity pΓ located in the vorticity center, the polynomial solutions of which determine stationary positions of the vortices included in this configuration. The procedure of generalization of differential equations related to the stationary positions of vortices to a general differential equation for a stationary configuration of vortices is substantiated. An algorithm for generalizing differential equations is described by introducing parameters into differential equations that reflect the equivalence of the stationary positions of vortices that are obtained from each other by transformations of rotation, stretching, and shear. Generalized differential equations are presented for some stationary configurations of vortices. A procedure of testing polynomials for determining the stationary configurations of vortices is proposed. An algorithm for testing polynomials has been developed, which makes it possible to check whether the tested polynomials are solutions of the generalized differential equation of some stationary configuration of vortices. To test polynomials, based on the tested polynomials and the generalized differential equation, a system of algebraic equations is compiled with respect to the parameters of the generalized differential equation. The existence of a solution to this system corresponds to the fact that the tested polynomials satisfy the considered stationary configuration. The architecture and operation algorithm of the program that automates the testing of polynomials to determine the stationary configurations of vortices is described.

   The possibility of using spike neural networks to solve the problem of author profiling texts in Russian has been examined on the example of the tasks of determining the gender and age of the author, as well as the task of distinguishing texts generated algorithmically and written by a person. A method has been developed to convert texts encoded by sequences of vectors obtained using the FastText language model into spike sequences. Within the framework of the task, two bodies of documents are used, the first of which is characterized by a large number of short texts, the second by four times fewer texts of significantly longer length. Such a choice of enclosures allows us to draw conclusions about the limitations and possibilities of the proposed coding method. The experiments show that the proposed text encoding method in combination with the spike topology used in the problem successfully solves the tasks assigned to it: the accuracy obtained corresponds to the baseline model (LinearSVC) on both cases according to the f1-score metric.

   The efficiency of methods of author profiling: determining the gender and age group of the author of the text, as well as the presence of deliberate distortion of the features of the text by gender, age or style has been analyzed. The corpus used in this work consists of various crowdsourced datasets. This is the most representative corpus of Russian-language texts containing markup for this task in Russian. In addition to classification algorithms based on support vector machines and deep language models, the use of graph neural networks in which text is represented by a set of morphosyntactic features is explored. The study allows us to estimate the current level of accuracy in solving the problems of determining the features of the author’s profile. The resulting accuracy and collected dataset can be useful as a benchmark for testing new machine learning methods.

   Brain-computer interfaces (BCIs) are a modern and promising interaction technology that significantly expands human capabilities. An actual objective is the fast and flexible development of adaptive BCI applications for various tasks and for a wide range of users, especially for people with disabilities. The decomposition of the system software architecture into components, which is one of the aspects of the development process, has been considered including the features of the BCI-based applications. The approach of functional decomposition, which is popular in the field of software development, including BCI interaction, has been analyzed. The application of volatility-based decomposition principle has also been proposed. These two principles have been compared on the example of designing a system that implements the control of a robotic device using BCI, for which common initial requirements have been determined and two functionality-based and volatility-based options for its software decomposition have been considered. Finally, the necessity to perform any modifications of the components due to various upgrades of the system has been analyzed. It has been shown that both decomposition approaches are applicable to solve the problem of designing systems with BCI interaction, but volatility-based decomposition demonstrates a higher resistance of the application architecture to changes due to the forthcoming of new functional requirements. Therefore, this decomposition method simplifies and optimizes the adaptation of the BCI application to changing operational conditions, which is beneficial from an economic point of view and positively affects the user experience.

   A scheme was previously substantiated for the emergence and functioning of ascending swirling flows, which naturally occur in the form of tornadoes and tropical cyclones. It has been shown that the cause of natural twist of an upward air flow in these flows is the rotation of the Earth around its axis. It has also been mathematically proven that the kinetic energy of this rotational motion of air comes only from the kinetic energy of the rotation of the Earth around its axis. It has been established that when the upward motion of air in swirling flows stops, the rotation of the Earth will twist flow to the other side and destroy its rotational motion. Taking into account the previously obtained analytical results, the motion of air in such flows has been numerically simulated. Namely, three-dimensional unsteady calculations simulate flows in a tropical cyclone with gas-dynamic parameters of the flow and its linear dimensions corresponding to the natural observation data. The occurrence of a flow and its transition to a steady state in a specific time have been calculated. The calculations carried out using an explicit difference scheme, which made it possible to parallelize the calculation procedure, have revealed the destruction of a tropical cyclone after a given external energy impact on it and the transition of the air flow in it into unstructured motion in a much shorter time than the time required for the flow to reach a steady state.

   Nickel ferrite is widely used in memory devices, computer, and satellite technologies because of its unique combination of a high magnetic susceptibility, semiconductor properties, chemical stability, and mechanical hardness. The NiFe₂O₄ compound is a solid solution that allows the introduction of various metal ions, thereby affecting the magnetic, mechanical, and dielectric properties of this material. Nanocrystalline powders of nickel ferrite doped with Cr³⁺ ions with a degree of substitution x = 0.1–1.5 have been obtained by autocombustion. According to the X-ray diffraction analysis, the prepared substances have the structure of nickel ferrite. When they are doped, a solid substitution is formed, accompanied by a decrease in the parameters of the cubic lattice and interplane distances. The morphology and size of the undoped nickel ferrite particles significantly differ from the chromium substituted samples. The scanning electron microscopy data have shown that the average particle size of doped nickel ferrite is about 40 nm, while as the calcination temperature increases, particles agglomerate and, as a consequence, increase in size. It has been found that chromium ion doping reduces the phase formation temperature of nickel ferrite.

   The effect of built-in electric fields on the hardness of light-emitting diodes (LEDs) based on monocrystalline gallium phosphide (wavelength of 655 nm) to gamma irradiation has been demonstrated for operating modes with and without separation of electron–hole pairs generated under irradiation in the builtin electric field of the p–n junction of a LED. Three stages of the light output power decreasing during gamma irradiation have been revealed. The possible physical reasons that served the formation of these stages of reducing the emission power of GaP LEDs have been discussed. It is shown that the separation of electron-hole pairs in the built-in field of the p–n junction increases their radiation hardness. This is confirmed by lower damage factors for stages I and II of power reduction for LEDs under the operating mode with the separation of electron–hole pairs generated under irradiation in the built-in electric field of the p–n junction under gamma irradiation.

   The measuring system for the in-reactor control of energy release over the reactor core volume by activating copper wire indicators in the “dry” channels of the VK-50 reactor (State Scientific Center Research Institute of Atomic Reactors) has been re-equipped including the modernization of both hardware and software and methodological parts. One of the reasons for the transition to a new measuring system was a rather large discrepancy in the measurement results when using the old equipment, both in the level of activity and in the form of distribution of activations between measurements. The results of the modernization have been presented. Changes both in the methodological measuring part and in the software processing of the measurement results with the determination of the distribution of energy release over the volume of the reactor core have been described. Information on test calculations of the previous calculation program and the new one is given. The final stage of verifying the operability of the scanning equipment of copper wire indicators was a comparison of the calculated and experimental data. As a result of the modernization, the CUPRUM program has been developed, involving the modern operating conditions of the reactor core and the types of computer equipment used. The measuring equipment for scanning the copper wire indicator has been replaced with a more modern one.