SovietRxiv · Open Access in English
Rediscovering the Soviet scientific archive, in English
25357 full-text translations 14926 English PDFs 22539 abstracts
Showing 50 of 25357 papers
This paper studies the large-time behavior of the energy of solutions to a mixed initial-boundary value problem for the wave equation in an unbounded exterior-type domain in Euclidean space. Using scattering eigenfunctions for the corresponding exterior domain, the solution and its energy are repres…
This paper presents deep seismic sounding evidence for high-velocity layers in the upper mantle beneath the western Black Sea basin and the rift valley of the Arabian Indian Ridge. Using bottom seismograph records, travel-time curves, and comparisons between observed and theoretical amplitude graphs…
The paper studies a singular two-dimensional integral equation arising in the theory of generalized analytic functions when the coefficients of the associated generalized Cauchy, Riemann system have first-order singularities. Using a Fourier expansion in the polar angle, the equation is reduced to p…
The paper constructs exact non-self-similar triple-wave solutions for the equations of potential unsteady gas dynamics in a polytropic gas with adiabatic exponent between 1 and 2. It seeks the sound-speed function and placement potential in a special algebraic-functional form, reducing the overdeter…
This paper constructs an analytic representation of the electron dispersion law of copper near the Fermi surface using a truncated Fourier expansion fitted by least squares to previously calculated ab initio energy values. The resulting five term expression reproduces the selected energies with a ma…
This note addresses extension problems for continuous maps into spheres and their connection with P. S. Aleksandrov’s question on bicompact compactifications. It proves that if a bicompactum is a countable union of bicompacts whose distinct pairwise intersections have dimension at most n minus 1, th…
The paper studies the existence and uniqueness of almost-periodic solutions for linear and nonlinear evolution equations in separable Banach spaces, including equations with unbounded operators depending almost periodically on time. Using limiting equations, dynamical systems on product spaces, comp…
This paper studies the complexity of normal algorithms associated with realizability for closed logico-arithmetical formulas of bounded length and with bounded realizations of certain propositional formulas under arithmetical substitution. It defines complexity as the length of an algorithm’s repres…
This paper studies growth rates of sums of independent random variables under conditions controlling the size of individual summands relative to normalizing sequences. It introduces classes of comparison functions and proves sufficient and sharpness results for strong laws of large numbers with vari…
The paper reports an electrostructural effect in oriented nematic liquid-crystal films, studied mainly in n-azoxyanisole with analogous observations in n-azoxyphenetole and mixtures. By applying voltage to thin films and observing the transmitted light, film surface, diffraction patterns, polarizati…
This paper examines the relation between amorphization and point defect formation in germanium and silicon subjected to medium-energy ion bombardment. Using Fourier analysis of amorphized germanium films, electron diffraction after layer removal, annealing experiments, and comparison with Monte Carl…
This paper proposes a model for the accumulation and redistribution of thermal energy in an atmospheric layer where heat transfer is intermittently blocked and released by free convection. Using the heat conduction equation with an effective thermal diffusivity that switches between an accumulation …
This paper extends parts of James’ theory of bases from Banach spaces to sequentially complete locally convex spaces with Schauder bases. It proves characterizations of shrinking bases through strong completeness and strong basis properties of the conjugate system, and shows that a basis is both shr…
The paper applies the method of functionals to generalized Zolotarev-Psheborsky minimax problems for polynomials subject to two linear constraints. It first establishes criteria for decomposing a finite sequence of functional values with respect to prescribed nodes, and gives necessary and sufficien…
The paper studies an integral equation of convolution type that models a smooth transition between two limiting paired equations with different kernels. Under summability of the kernels and nonvanishing conditions on the corresponding Fourier transforms, the equation is transformed by Fourier method…
This paper estimates vertical turbulent mass fluxes in the ocean, a quantity not yet directly measured, and relates them to transformations between turbulent kinetic energy and the potential energy of stratification. It derives surface boundary contributions from precipitation, evaporation, heat exc…
The paper studies groups in which every subgroup that is not completely splittable is invariant, extending earlier work on groups with invariant noncyclic or otherwise exceptional subgroups. Using known classifications of finite groups whose proper subgroups are completely splittable, the authors cl…
This paper studies uniform deviations between continuous functions and algebraic polynomials obtained either by best approximation or by discrete least squares with a positive weight on equally spaced nodes. It proves a general bound, depending only on the degree, number of nodes, and weight, for th…
This paper studies boundary limit sets of real harmonic functions in the unit ball of three-dimensional Euclidean space, motivated by earlier results on ambiguous boundary points and asymptotic values. It proves the existence of a harmonic function such that, for every boundary point and every real …
This paper examines the role of uncompensated space charge introduced by separated auroral electron and proton fluxes in producing magneto-ionospheric disturbances. Using a two-dimensional ionospheric model with calculated ionization, conductivity, charge density, and electric-field profiles for an …
The paper develops a theory of symmetric Banach spaces of measurable operators in Segal spaces with a measure on projections. It introduces distribution functions and s-numbers for measurable operators, proves minimax and approximation formulas, establishes a Schmidt-type decomposition, and relates …
This paper studies reduced extremal polynomials on the interval [0,1] that share a prescribed subdistribution of alternation nodes. It describes the structure of all such polynomials through perturbations by the squared resolvent of the common subdistribution, establishes when the corresponding set …
This note gives structural representations for classes of harmonic and analytic functions in the unit disk associated with the operator defined by a system of weight functions. It defines harmonic functions whose transformed boundary integrals are uniformly bounded, analytic functions whose transfor…
The paper addresses the recursive analogue of decomposing fields of sets generated by sufficiently strong Kolmogorov type R-operations, extending the comparison with classical descriptive set theory and Kleene’s hyperarithmetic hierarchy. It defines stabilization and external indices for recursive s…
The paper studies a differential pursuit problem in which the pursuer and evader are governed by controlled dynamical systems with bounded closed control sets, and meeting is defined by membership of their relative position in a prescribed closed set. It formulates conditions under which an approxim…
This paper reports the synthesis and crystallographic characterization of new oxide garnets containing hexavalent tellurium, with attention to substitution of divalent ions by mono- and trivalent ions in garnet structural sites. Ceramic samples were prepared by heating carbonate and oxide mixtures i…
This paper extends James’s theory of boundedly complete and shrinking bases in Banach spaces to minimal, biorthogonal sequences, and studies how these linear topological properties reflect structural features of the space. It proves duality results for boundedly complete and spanning minimal systems…
This paper calculates the sixth relative gravitational moment of Jupiter and Saturn using the third approximation theory of figures for hydrostatically equilibrated rotating planets. The authors formulate the dependence of gravitational moments on the shape parameters of internal level surfaces, sol…
This paper examines whether the orientation of ejecta from volcanic directed explosions is related to regional tectonic stress fields as inferred from earthquake focal mechanisms. Using the 1964 Shiveluch eruption as the principal case, it compares the azimuth of directed deposits with nodal planes …
This note studies the emergence of limit cycles from an equilibrium of a smooth or analytic differential system with one pair of purely imaginary characteristic roots, remaining roots off the imaginary axis, and a nonzero Lyapunov quantity of order \(2m+1\). Using reductions to a special normal form…
The paper treats the reconstruction of a centrosymmetric basic system from its vector system for crystals in the Fedorov group P overline 1, extending a previously proposed procedure for acentric crystals. Under the condition that no additional vector coincidences raise peak multiplicity above two, …
This paper examines finite-time damping and controllability for a simple distributed oscillatory system consisting of two one-dimensional wave lines joined at a common controlled endpoint, with fixed opposite endpoints. Using the finite control method, the problem is reduced to interpolation conditi…
The paper studies whether infinite commutative rings can be endowed with a nondiscrete ring topology, beyond the trivial discrete topology. It proves this in full generality by reducing the problem through a series of structural lemmas concerning nil ideals, square-zero ideals, torsion and torsion-f…
The paper studies how equimorphisms of hyperbolic spaces act on curves approaching the absolute and on pairs of curves lying on the absolute. It refines earlier results showing preservation of tangency by distinguishing three qualitative types of contact, zero, finite, and infinite order, defined th…
The paper examines the multiple-scattering effect in ion scattering by crystals, focusing on why narrow energy peaks are most clearly observed when the glancing angle is close to half the scattering angle. Using a two-atom scattering model with the Firsov interaction potential, the author derives co…
This paper investigates how the form of regular surface perturbations affects the breakup of low-viscosity liquid jets into drops, with particular attention to suppressing satellite microdrops. Experiments with water and molten ammonium nitrate used pressure pulses from an oscillating membrane to va…
This paper addresses spectral estimation for multidimensional homogeneous random fields when observations are available only on lower-dimensional sections, such as two intersecting lines, rather than over an area or volume. It proposes an estimator formed from the real part of the product of the Fou…
This paper studies the complexity of realizing propositional formulas in the framework of normal algorithms and logical arithmetic, extending earlier notions from formulas in one variable to arbitrary propositional formulas. It formulates a sufficient condition for a formula to have no recursive upp…
This paper examines how discrete admixtures of solid particles or liquid droplets alter the structure and spreading of a turbulent gas jet. Using Prandtl mixing-length theory and momentum balance for turbulent eddies containing particles, it derives estimates for the reduction of pulsation velocitie…
This note studies reduction problems in pure higher-level logic over type scales of sets, with attention to spectra of formulas and definability of cardinal classes. It introduces a translation on types relating truth over a set to truth over iterated power sets, then uses it to reduce questions abo…
This paper studies locally bicompact topological groups through the topology on classes of conjugate closed subgroups, identified with quotient spaces by normalizers. It proves that if conjugacy classes of bicompact subgroups topologically generated by one element are bicompact, then the bicompact e…
The paper studies a multidimensional multiphase Stefan-type free-boundary problem for a general second-order linear parabolic equation in noncylindrical domains with piecewise smooth boundaries, allowing both closed and nonclosed phase fronts. For the two-dimensional case, with extension to higher d…
The paper formulates and studies a general moment problem in interpolation theory for analytic functions, defined by contour integral conditions involving a univalent function, auxiliary analytic factors, and prescribed sequences of complex numbers. Under the assumption that the image domain is inva…
This paper proposes an averaged formulation for the radiation transport equation in low-temperature plasma, addressing cases where strong nonmonotonic spectral dependence of the absorption coefficient makes conventional Planck, Rosseland, or multigroup averaging inefficient or inaccurate. For plane-…
This note studies generative grammars under bounds on the number of auxiliary symbols that may occur during derivations, called active capacity, distinguishing bounded and uniformly bounded variants. It reduces the analysis to context-sensitive grammars, introduces a density measure for derivation t…
This paper treats the direct problem of unsteady and steady ideal-gas flow in Laval nozzles of prescribed geometry, including subsonic, transonic, and supersonic regions. The authors formulate the gas-dynamic equations in transformed coordinates and describe a finite-difference marching algorithm wi…
This paper interprets an observed break near 290 degrees Celsius in the thermal expansion coefficients of artificial fluorophlogopite along the a and b axes, with no corresponding anomaly along c, as evidence for a second-order phase transition confined to the basal plane. Using geometric relations …
This paper studies uniqueness in mixed inverse problems of potential theory, especially the determination of both the shape of a body and its density from exterior volume potentials or simple-layer potentials. Using the method of generalized moments, it proves uniqueness theorems for classes of cont…
The paper proposes a regularization of singular operator expressions in quantum field theory, applied to the Hamiltonian of the scalar fourth-power interaction. It constructs a modified Fock-type Hilbert space using a positive symmetric kernel and defines corresponding analogues of annihilation and …
