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 note studies constructive sets equipped with an equality relation, whose elements are words, and mappings between them defined by normal algorithms. It introduces a classification of infinite such sets according to enumerability properties of their bases and decidability or enumerability proper…
The study determines the crystal structure of liroconite, Cu2Al[AsO4][OH]4·4H2O, to clarify structural principles in copper arsenate and phosphate minerals related to the turquoise group. X-ray rotation and layer-line data using MoKα and CuKα radiation were analyzed through Patterson maps, electron-…
This note determines the maximum possible number of edges in a finite connected simple undirected graph with a prescribed number of vertices and radius. After recording bounds on vertex degrees, including a bound for pairs of vertices at distance at least three, it defines the extremal function for …
This paper analyzes the initial stage of plane unsteady outflow of a polytropic compressed gas from a tube after removal of a wall, with attention to the formation of lateral rarefaction waves in addition to the central one-dimensional Riemann wave. Using characteristic equations and self-similar va…
The paper considers the well-known problem of the analytical design of a controller for a linear controlled system. However, in contrast to existing developments, this study examines a more complex nonlinear case rather than a quadratic optimality criterion. For the aforementioned criterion, the pro…
This paper addresses the synthesis of adjustment algorithms for a model reference self-tuning control system with time-varying plant coefficients. The system is reduced to an error equation between the controlled object and a reference model, and integral laws for the adjustable regulator coefficien…
This paper analyzes the damping of the Earth’s radial normal oscillations using the Gutenberg Bullen model A and previously developed perturbation methods for nearby Earth models. The authors present formulas for computing derivatives of radial eigenfrequencies with respect to density, bulk modulus,…
This paper examines the velocity distribution function of gas molecules near a solid wall when a temperature gradient is applied tangentially to the wall, a problem relevant to the calculation of thermal slip. The authors solve the stationary Boltzmann kinetic equation more directly than in their ea…
The non-stationary problem \begin{equation} u_{xx}=k^2(x)u_{tt}, \tag{1} \label{1} \end{equation} is investigated, where $k(x)=k_0$ for $xx_0$, under the initial condition $u_0(x,t) = \mu(t-k_0x)$ for $tz_0$$ is equal to $\lim_{t\to\infty}u(x,t)=\frac{2\mu_0k_0}{k_0+k_1}$. That is, the limit is the …
The paper studies decidability questions for elementary theories of lattice-ordered Abelian groups, structurally ordered Abelian groups, K-groups, and K-lineals. It proves broad undecidability results for classes of lattice-ordered Abelian groups containing certain Archimedean divisible examples wit…
The paper reports an X-ray structural study of the double molybdate KY(MoO4)2, a compound distinguished among related molybdates and tungstates by pronounced cleavage. Using Weissenberg photographs with Mo K alpha radiation, Patterson projections, and least-squares refinement, the structure was dete…
This paper studies Chebyshev sets in normed and Banach spaces, with emphasis on approximative compactness, suns, and convexity. It proves a key extension lemma showing that certain distance-growth sets meet every sphere, then applies it to exclude approximatively compact Chebyshev complements of bou…
This study investigates the long-range action of active centers on crystalline surfaces and its relation to surface structure. Using electron-microscopic chemical and electrical decoration through amorphous parlodion layers of varying thickness, the authors examined mica, silicon, quartz, sodalite, …
This paper proves an existence theorem for closed convex hypersurfaces in Euclidean space whose curvature functions satisfy a prescribed linear relation with positive continuous even coefficients on the unit sphere. After recalling the definition of curvature functions via the surface functions of e…
This paper derives the inviscid two-fluid hydrodynamic equations for London superconductors from microscopic nonequilibrium equations for normal and anomalous correlation functions in the generalized Hartree-Fock approximation. By separating gauge-dependent phase factors, introducing the superfluid …
A constitutive equation is proposed for describing metal creep under conditions that also account for the limiting dynamic stress strain diagram and the transition between elastic and plastic deformation. The formulation generalizes a previously used dynamic loading equation by introducing experimen…
The paper examines how Petrov’s classification can be extended to four-dimensional complex metric spaces by mapping the metric and curvature tensors to a complex bivector space and studying the elementary divisors of the associated lambda matrix. It argues that real metric subspaces generated from t…
This paper examines the formation of hydrocarbon contamination on surfaces irradiated in vacuum by narrow electron beams, questioning explanations based mainly on beam-induced heating. It develops a diffusion model in which electron irradiation lowers the concentration of adsorbed hydrocarbon molecu…
This paper models energy exchange when atoms with incident energies of about 1 to 20 eV interact with the surface of an ideal crystal, treating the process classically and neglecting thermal motion, sputtering, and ionization. Simple cubic, body-centered cubic, and face-centered cubic crystals are r…
This paper constructs an equation of state for crystalline trinitrotoluene using the Debye, Einstein, Grüneisen approach, with separate treatments of intermolecular and intramolecular contributions to interaction energy and thermal motion. The model parameters are determined from experimental data o…
This paper reports an in situ X-ray diffraction study of structural transformations in zinc fluoride under pressures up to about 130 kbar at 25 and 300 degrees Celsius. Using a high-pressure chamber with temperature control and pressure calibration by sodium chloride compressibility, the authors fou…
This note introduces new asymptotic characteristics of the unit sphere of a Banach space, denoted by delta and beta functions, defined through extremal behavior over finite-dimensional subspaces and subspaces of finite codimension. It establishes inequalities and continuity properties for these char…
This paper studies invariant subspaces of weighted shift operators on Hilbert sequence spaces, with emphasis on when such operators are unicellular, meaning that their invariant subspaces are totally ordered by inclusion. It gives sufficient regularity and summability conditions on the weights for u…
This paper examines the propagation of electromagnetic waves in general relativity using exterior differential forms for Maxwell’s vacuum equations on a hyperbolic Riemannian space-time. It derives the generalized wave equation for the electromagnetic 2-form and relates curvature terms in this equat…
This paper reports the hydrothermal formation and characterization of rare-earth tungstate chlorides LnWO4Cl, where Ln is Ce, Pr, or Nd, produced from intermediate rare-earth tungstates in ammonium chloride containing media. The authors describe synthesis conditions, crystal habit, chemical and ther…
The paper studies flatness properties of generalized classical rings of fractions for associative rings with identity. Using the elementary relation-based definition of flat modules, it proves that a left generalized classical ring of fractions R(S), when it exists for a multiplicatively closed syst…
A solution is sought for an equation $$L_1L_2\dotsb L_n=f\quad(y>0),$$ which is strictly hyperbolic in a certain bounded domain $D$, where $$L_iU\equiv y^{a_i}U_{xx}-U_{yy}+a_i(x,y)U_x+b_i(x,y)U_y+c_i(x,y)U\quad(i=1,2,\dots,n),$$ satisfying the initial data $$\quad\lim_{y\to0}\frac{\partial^iU(x,y)}…
This paper examines irreversible volume changes in polymer specimens during tensile deformation as evidence of microscopic loosening by pores and cracks. Cylindrical specimens of fluoroplastic-4, rigid vinyl plastic, and organic glass were tested to fracture under constant or stepwise increasing loa…
This article presents a commemorative scholarly biography of Iosif Zakharovich Shtokalo on the occasion of his seventieth birthday, tracing his education, teaching career, research, and public and organizational work. It surveys his mathematical contributions to linear differential equations with va…
The paper examines the use of noncompact and non-fully antisymmetric group structures in the geometric theory of gauge fields, extending earlier formulations that effectively relied on locally compact groups with totally antisymmetric structure constants. It analyzes the one-dimensional analogue of …
The paper examines how incoherent electron scattering by an object affects the visibility of interference fringes produced with an electrostatic Fresnel biprism. Using Michelson visibility and a two-beam interference model, the authors represent the transmitted electron beam as a superposition of co…
In problems related to determining the number of limit cycles bifurcating from a singular point of the second group, it is sometimes (RZhMat, 1965, 7B199) essential to establish the fact that for a system close to a Hamiltonian one, depending on a parameter $\mu$, under certain additional conditions…
The paper treats a generalized version of Shtaerman’s contact problem for two elastic cylinders of nearly equal radii, incorporating friction and possible regions of slip and rigid adhesion. Using Kolosov-Muskhelishvili potentials, the author derives contact equations from equality of boundary curva…
This paper examines dynamic remanent magnetization produced in magnetites and magnetic rocks by impacts in a constant magnetic field, with attention to its magnitude, direction, and stability. Experiments on magnetite, diorite porphyrite, and other rocks show that impact-induced magnetization tends …
This paper studies regularized sums of zeros of entire functions represented as finite sums of exponential factors multiplied by functions with sectorial asymptotic expansions, a class arising in parameter-dependent boundary value problems for ordinary differential equations. The authors define an a…
This paper analyzes energy dissipation in a turbulent gas containing dilute suspended solid particles at large Reynolds number, assuming local homogeneity, isotropy, stationarity, and particle sizes small enough for Stokes drag to apply. It derives estimates for the mean square relative velocity of …
This paper examines the structure and field-induced orientation of nematic n-azoxyanisole using X-ray diffraction and cylindrical distribution functions derived by Fourier transformation. The authors compare specimens oriented in magnetic fields, constant electric fields, and alternating electric fi…
This paper analyzes the far-field damping of disturbances produced by a body of revolution in a supersonic flow of a viscous, heat-conducting gas. Starting from the axisymmetric continuity, Navier-Stokes, and heat-transfer equations, the authors introduce coordinates aligned with the characteristics…
This paper studies self-similar asymptotic solutions of the diffusion equation for an ionized gas with bimolecular recombination in infinite domains, focusing on planar and spherical symmetry. For the planar case, the authors reduce the problem to an ordinary differential equation for the similarity…
This note reformulates Eckmann-Hilton type duality for functors in the category of weak homotopy types of pointed spaces, replacing an earlier point-set topological setting in order to make the construction homotopy invariant and avoid related topological difficulties. It defines continuous functors…
The equation \begin{equation} \ddot{\varphi}-f_1(\varphi)\dot{\varphi}-f_0(\varphi)=0\tag{1} \label{1} \end{equation} is considered in the case where $f_0(\varphi)$ and $f_1(\varphi)$ are trigonometric polynomials of degree no higher than $n$, where $n$ is a fixed natural number. Equation (1) is equ…
A system of differential equations \begin{equation}\frac{dx}{dz}=\sum_{j=0}^pa_j(z)y^{p-j},\quad\frac{dy}{dz}=\sum_{j=0}^kb_j(z)x^{k-j}\tag{1}, \end{equation} is considered, where $a_j$, $b_j$ are holomorphic functions and $k\ge p\ge2$. Necessary and sufficient conditions are provided for the movabl…
This paper studies completeness of the system of all translates of a function in weighted spaces whose norm involves an even subadditive weight, and relates this problem to regularity of the corresponding convolution normed ring. It proves that if the weight satisfies an integrability condition, the…
The paper studies uniform rational approximation on a plane compact set whose interior has several components, asking when approximation on each component can be glued to approximation on the whole set. Using Gleason parts for the algebra R(X), it proves a necessary and sufficient condition for ever…
The paper studies structural restrictions on extremally disconnected compact spaces and their homogeneous subspaces. It proves that every infinite compact subspace of an extremally disconnected space contains a copy of the Čech compactification of the natural numbers, yielding cardinality consequenc…
The paper examines boundary conditions for the Navier-Stokes equations in a monatomic rarefied gas when the gas-surface interaction law is treated as an arbitrary boundary transform rather than a prescribed specular-diffuse model. Using a Grad-type representation of the distribution function and req…
