RussiaRxiv · Open Access in English
Translated research papers from Russian journals and repositories
15540 translated records Original PDFs retained
Showing 50 of 15540 papers
Generated abstract This paper studies uniform convergence of variational-difference schemes for elliptic Dirichlet problems, with emphasis on estimates that reflect the smoothness of the coefficients, data, boundary, and mesh geometry. It constructs schemes on simplicial complexes, introduces complexes with alpha-symm…
Generated abstract The paper studies hyperspaces of nonempty closed subsets with the Vietoris, or exponential, topology, focusing on the subspaces of compact sets and finite subsets. It establishes criteria relating topological properties of a space to those of its hyperspaces, including normality, paracompact p-space…
Generated abstract This paper theoretically investigates self-focusing of intense axially symmetric monochromatic light beams in a nonlinear Kerr medium when the incident beam has a spherical phase front produced by a converging lens. The authors formulate the propagation problem in dimensionless variables and solve i…
Generated abstract The paper studies the decay of a discontinuity for systems of two quasilinear conservation laws and gives an example showing that the usual Lax monotonicity condition does not by itself ensure existence of a self-similar Riemann solution. For the system with fluxes \(f=3\ln u+v\) and \(\varphi=2/u\)…
Generated abstract This paper develops a third-order theory for the figures of rotating liquid planets in hydrostatic equilibrium, motivated by the need to model Jupiter and Saturn with accuracy comparable to observed gravitational moments. It represents equipotential surfaces by spheroidal expansions with shape param…
Generated abstract This paper proposes a semiempirical method for constructing approximate shock adiabats of solids over pressures extending from experimentally accessible dynamic-compression ranges to ultrahigh pressures where hydrodynamic and Thomas-Fermi descriptions are applicable. The approach decomposes pressure…
Generated abstract This paper applies dimensional analysis to the hydrodynamic motion of interplanetary gas disturbed by solar chromospheric flares. Assuming approximate power-law forms for solar-wind density and velocity, and neglecting pressure, gravity, rotation, viscosity, heat conduction, and electromagnetic forc…
Generated abstract The paper investigates the origin of weak electron paramagnetic resonance lines associated with nitrogen ions in a natural diamond crystal, questioning earlier interpretations that attributed them to unpaired electrons in carbon, nitrogen bonds. Using angular dependences of EPR spectra measured at 9…
Generated abstract The paper studies maximum principles for a class of second order mixed elliptic-hyperbolic equations with singular lower order coefficients in a domain divided by a transition line. It first proves a characteristic absolute extremum principle for an associated hyperbolic equation in a triangular cha…
Generated abstract This note proves an approximation theorem for analytic functions in the weighted Banach spaces defined by integrability of \((1-|z|^2)^q|\varphi(z)|\) over the unit disk. It shows that every such function can be approximated in the corresponding norm by rational functions with at most simple poles o…
Generated abstract The note studies stability of bases and defective bases in locally convex spaces under perturbations of the basis vectors. It gives criteria for equicontinuous, absolute, and Bessel bases in complete locally convex spaces, including conditions under which a perturbed sequence remains a basis equival…
Generated abstract This paper develops a superconductivity theory that incorporates crystal structure beyond the nearly free electron and effective mass approximations. Using a strongly bound electron model, orthogonalized atomic functions, and an electron, phonon interaction Hamiltonian, it derives secular equations …
Generated abstract The paper examines the possibility of direct acceleration of charged particles by energy stored in an inverted paramagnetic medium. It formulates a self-consistent electrodynamic model for a modulated current passing through such a medium near magnetic resonance, derives nonlinear equations for the …
Generated abstract The study investigates charge accumulation in liquid-phase epitaxial gallium arsenide emitting p-n structures doped with silicon in both regions. Using pulsed excitation at room temperature, the authors recorded current, voltage, and luminescence pulses, examined the emission region and spectrum, an…
Generated abstract The paper formulates a two-player zero-sum variant of the discrete optimal stopping problem on an increasing sequence of sigma-algebras, where each player may stop only at times determined by the sign of an adapted process and the payoff is the stopped value of another adapted process. Under an inte…
Generated abstract This paper reports low-temperature electrical resistance measurements on lutetium films condensed onto glass substrates cooled by liquid helium, with film thicknesses from about 300 to 8000 Å and with measurements before and after annealing. All investigated films showed a distinct resistance minimu…
Generated abstract This paper studies eigenfunction expansions for a second order differential equation in a Hilbert space with an unbounded operator coefficient of the form A minus q(t), where A is self-adjoint and semibounded below and q(t) is bounded self-adjoint. It develops weak and strong solution theory for the…
Generated abstract This study examines the range of optical thicknesses over which Bouguer’s law remains applicable for laser radiation propagating through water fog, taking into account forward and multiple scattering recorded by a finite aperture receiver. Experiments in an artificial fog chamber compared simultaneo…
Generated abstract A microscopic formulation of the direct Josephson effect is developed for two identical superconductors separated by a potential barrier. Starting from Gor'kov Matsubara equations in a basis of one-particle states in the barrier field, the authors introduce a time-like representation that averages o…
Generated abstract The paper reports methods for fabricating cadmium telluride p-n junctions and examines their electrical and detector properties. Junctions were produced in p-type single-crystal CdTe by indium or gallium alloying and diffusion, or by boron ion bombardment, with improved surface treatment reducing le…
Generated abstract This paper develops a method for studying Temlyakov-type integrals in their domain of nonanalyticity using first-order linear homogeneous differential operators. The approach combines a generalized Newton-Leibniz formula for such operators with formulas reducing multiple integrals to repeated integr…
Generated abstract The paper develops a method for deriving interpolation theorems in symmetric Banach spaces of measurable functions on the unit interval. The approach represents norms in such spaces as suprema of Lorentz-type norms and uses boundedness results for operators between these auxiliary spaces, together w…
Generated abstract The paper develops a two-sided collecting process for words in free groups with respect to bases of basic commutators, motivated by limitations of the Hall and Shirshov processes when computations are carried out only modulo a fixed term of the lower central series. It defines natural and layerwise …
Generated abstract The paper studies commutative nilpotent associative algebras over the complex numbers through the complete lattice of their ideals, asking which algebraic properties and isomorphism classes can be recovered from this lattice. It develops lattice-theoretic characterizations of dimension, annihilators…
Generated abstract The crystal structure of hydrothermally formed Pr3WO6Cl3 was determined from single-crystal X-ray diffraction data for a hexagonal cell with space group P63/m, using Patterson analysis, electron-density syntheses, and least-squares refinement. The final centrosymmetric model, refined against 923 non…
Generated abstract This paper examines whether small secular changes in gravity can be detected over broad areas despite measurement errors, using repeated gravimetric observations from the Middle Volga and Baltic regions of the Russian Platform. The author compares gravity measurements made between 1949 and 1968, con…
Generated abstract The paper proposes a family of successive approximation methods for solving nonlinear functional equations in Banach spaces under differentiability and local invertibility assumptions. The iteration is constructed by choosing operator coefficients recursively so that the first k derivatives of the i…
Generated abstract This study examines the microstructure of artificial polycrystalline diamonds, ballas and carbonado, using transmission electron microscopy of mechanically comminuted, electron transparent fragments. The observations show wedge shaped crystallites with cleavage steps often near {112}, {110}, and {11…
Generated abstract This paper studies optimal completion time in a linear differential pursuit problem with convex compact control sets and a linear terminal subspace. Building on Pontryagin’s construction of a guaranteed pursuit time defined by first inclusion in an integral of convex-set differences, the authors ask…
Generated abstract This paper develops a theoretical basis for studying the piezomagnetic response of magnetically anomalous bodies to time varying stresses in the Earth’s crust. Using potential theory, the authors derive expressions for temporal changes in magnetic potential and in the vertical magnetic component, se…
Generated abstract The paper studies periodic solutions of the one-dimensional diffusion equation on a finite interval, motivated by self-oscillatory phenomena previously treated mainly for semi-infinite domains. It formulates the bounded-domain problem with a fixed concentration at one endpoint and a nonlinear, possi…
Generated abstract This paper studies peripherally bicompact tree-like spaces, using earlier results that such spaces have bases of connected open sets with finite boundaries and are linearly connected. It proves that the density of such a space equals its weight, establishing in particular that separability implies c…
Generated abstract This paper addresses the stationary motion of a charged particle beam in an axisymmetric external electromagnetic field while accounting for the beam’s own space charge. A self-consistent formulation couples particle trajectory equations with Poisson’s equation for the electric potential, and an ite…
Generated abstract This paper addresses the arithmeticity problem for lattices in semisimple real Lie groups, focusing on noncompact finite-volume quotients and irreducible pairs in real rank at least two. It outlines a proof that such a discrete subgroup is commensurable, along a parabolic subgroup, with the rational…
Generated abstract This note studies structural closure operations on classes of groups, with emphasis on Baer groups and their relation to nilpotent and radical constructions. It first constructs, for each integer n at least 1, a Baer p-group that is not generated by its n-generated nilpotent subgroups, using iterate…
Generated abstract This note studies whether Lagrange interpolation at an arbitrary infinite triangular matrix of nodes on a finite interval can be made convergent for every function in the class \(ACG_*\). Building on known positive results for absolutely continuous functions under Chebyshev and related node systems,…
Generated abstract The paper studies boundary-value problems for a class of high-order differential-operator equations in a Hilbert space, termed partially hyperbolic, extending known results for first and second order cases to arbitrary order. It formulates weighted function spaces and analyzes equations on the whole…
Generated abstract This paper examines pressure-induced changes in the electrical resistance of rubidium, cesium, and calcium, with emphasis on their use as reference points for high-pressure calibration. Using modified three-stage and four-stage high-pressure apparatuses calibrated with known transitions, the authors…
Generated abstract The paper studies the computation of all simple eigenvalues of a Fredholm integral operator whose moduli exceed a prescribed threshold, for kernels belonging to specified smoothness classes and under stability and separation assumptions. It develops deterministic approximation and iteration schemes …
Generated abstract This paper reports year-round measurements of the effective dielectric constant and specific volume resistivity of young and pack Arctic drift ice over the frequency range 100 Hz to 1 MHz. Ice samples from different depths were studied with guarded flat capacitors, with temperature and salinity cont…
Generated abstract This paper develops an operational calculus for closed densely defined linear operators in countably normed locally convex spaces whose resolvents may be unbounded and whose spectrum may fill the complex plane. Under sectorial hypotheses expressed through a finite asymptotic resolvent expansion and …
Generated abstract The paper studies regularization of minimization problems for a continuous convex functional on a bounded closed convex subset of a Hilbert space, where ordinary minimizing sequences need not converge strongly because the minimizer may be nonunique. It proposes an algorithm based on intersecting the…
Generated abstract This note studies quantitative stability estimates for epsilon-quasiconformal mappings of the three-dimensional unit ball onto itself, under a normalization fixing three boundary points. Extending earlier planar results, it derives nonsharp bounds for the deviation of such mappings from the identity…
Generated abstract The paper studies topological entropy for two-sided topological Markov chains defined by finite or countable directed graphs, where the countable case is complicated by the noncompactness of the path space. It defines entropy as the supremum of the logarithms of the maximal eigenvalues over finite s…
Generated abstract The paper studies inertial motion of a body of homogeneous deformation as a nine degree of freedom mechanical system, extending earlier work that assumed vortex-free motion and spherical symmetry. It formulates the kinetic and internal energies, derives equations of motion for small deformations, an…
Generated abstract The paper studies discrete Wiener-Hopf equations in a quarter-plane with absolutely summable data and kernel, seeking solutions in l1. It establishes Fredholm, or Noether, criteria for the associated operator in terms of nonvanishing of the symbol on the two-torus and zero winding indices in each co…
Generated abstract The crystal structure of lanthanum pyrogermanate, nominally La2Ge2O7, was determined to identify the germanium oxygen units present in the compound. Single crystal X-ray diffraction data from a triclinic crystal were analyzed in space group P1bar, with heavy atom positions obtained from Patterson an…
Generated abstract This paper applies Zubarev’s nonequilibrium statistical operator method to irreversible processes in which interacting subsystems exchange only small amounts of energy, so that the distribution may be treated as locally Gibbsian on isoenergetic surfaces. A general set of kinetic equations is derived…
Generated abstract This paper studies eigenfunctions and spectral properties of the polyharmonic operator on an arbitrary domain, beginning with solutions of a polyharmonic eigenvalue equation. It proves a spherical mean-value formula for such solutions and their iterated Laplacians, involving Bessel functions and exp…
Generated abstract This note extends Reifenberg and Morrey type results for the multidimensional Plateau problem to compact subsets of a compact Riemannian manifold that satisfy prescribed Čech homological conditions. It defines classes of compact sets with a given algebraic boundary relative to a compact set and with…
