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 linear differential games governed by a controlled linear vector differential equation, with two players choosing controls on a unit sphere and with termination defined as reaching a prescribed subspace. It formulates sufficient geometric conditions, involving convexity and local c…
This paper studies homotopy properties of complements of locally flat codimension two spheres in Euclidean space for dimensions at least five, with particular attention to finite and infinite connected sums of knots. It proves finite generation of the fundamental group of any such complement and, un…
Spectral and temporal characteristics of lasing in a CaF2:Sm2+ crystal excited by a ruby laser were investigated at low temperatures. Using prism and high dispersion spectrographs together with nanosecond oscillographic recording of selected spectral components, the study follows how emission change…
The paper treats ultrasound absorption by conduction electrons in a metal under a strong quantizing magnetic field, where the classical Boltzmann equation is no longer applicable. It formulates a relaxation-time density-matrix description that preserves gauge invariance through a locally equilibrium…
The paper studies penalty methods for convex programming problems with inequality and equality constraints, comparing the original constrained maximization problem with auxiliary problems in which part of the constraint violation is incorporated into the objective. It develops estimates relating opt…
This paper studies stationary and nonstationary Prandtl boundary-layer systems for axisymmetric incompressible flow past bodies of revolution. By applying a Crocco-type change of variables and constructing solutions through the method of lines, it derives a priori estimates for the resulting degener…
This study examines the vertical distribution of cloud condensation nuclei in the free atmosphere using aircraft soundings and a flow-through photoelectric diffusion chamber operated at several supersaturations. Measurements from nine daytime clear-weather flights over several regions in 1966 show t…
The paper studies best approximation in \(L_p(D)\), \(1<p<\infty\), of functions on a bounded domain by sums of finitely many plane waves with prescribed directions. Using a functional analytic extremal lemma and a characterization of generalized plane waves as solutions of constant coefficient diff…
This paper examines the temperature dependence of the first magnetic anisotropy constant in single-crystal ferrites with spinel structure in relation to spontaneous saturation magnetization. It notes that the classical tenth-power law predicted for cubic crystals is not generally supported by experi…
The paper studies provability in Ackermann’s calculus of strict implication and in the related Anderson and Belnap system, treated jointly as systems of strict implication. Using Ackermann matrices, it establishes several necessary conditions for derivability, including polarity constraints on share…
The paper examines how the radial distribution of Alfvén speed in the magnetosphere affects the periods of stable geomagnetic pulsations attributed to magnetosonic resonances. Using satellite and whistler evidence for a sharp plasma density decrease near four Earth radii, it argues that the resultin…
The paper studies coefficient estimates for univalent functions in the unit disk, including functions with p-fold rotational symmetry, using logarithmic coefficients and associated functions generated by exterior univalent mappings. Building on an inequality for these associated functions, it proves…
This note addresses the synthesis of automatic control systems when practical design constraints make an unrestricted optimal feedback law difficult to find or implement. Instead of seeking an arbitrary control function of the state, it assumes a prescribed control-law structure containing finitely …
This paper examines how the luminescence quantum yield of neodymium glass affects the energy efficiency of stimulated emission in optical quantum generators. The authors measured total and 1.06 micrometer band luminescence yields for Nd3+ glass with 2 percent and 6 percent activator concentrations u…
This paper determines the maximum obtainable work from an isolated thermodynamic system consisting of a heat source and a refrigerator with finite heat capacities. Using Gibbs’ principle and heat balance relations for continuous sequences of cycles, it compares co-current and counter-current heat ex…
This note develops a relaxation-theoretic treatment of Jacobi methods for diagonalizing symmetric matrices by successive plane rotations. It formulates the decrease of the off-diagonal quadratic functional in terms of relaxation multipliers and angles, giving necessary and sufficient conditions for …
The paper specifies the integrability criteria for three nonlinear second-order differential equations. Bibliography: 8 items.
This paper extends Maslov’s inverse method for establishing derivability in classical predicate calculus with function symbols from prenex formulas to formulas of arbitrary, including non-prenex, form. It introduces generalized notions of atoms, links, favorable sets, and modified construction rules…
This study investigates whether silicon carbide undergoes an α to β structural transformation analogous to those used in the synthesis of diamond and cubic boron nitride. Several hexagonal silicon carbide powders, including industrial, high-purity, and single-polytype 6H materials, were subjected to…
This paper derives equations for electromagnetic fields and general electromagnetic potentials in homogeneous anisotropic media with an arbitrary complex permittivity tensor. Using algebraic elimination for Maxwell’s equations with constant coefficients, it shows that each field component satisfies …
This study examines whether bulk pure nickel can acquire field-induced uniaxial magnetic anisotropy when its structure is made closer to that of thin ferromagnetic films by severe plastic deformation. Nickel foil reduced by 99 percent rolling was annealed in a 6000 Oe magnetic field at different tem…
This note establishes general integral representation formulas for holomorphic functions in several complex variables, especially in convex complete circular domains and convex domains of complex space. The argument first derives an auxiliary formula for functions holomorphic in star-shaped domains,…
This study examines the optical absorption and electron paramagnetic resonance behavior of cobalt and nickel in fluoroberyllate glasses. Glasses of varied BeF2 based compositions doped with CoF2 or nickel compounds were prepared and measured spectroscopically, including EPR at room temperature and 7…
This study examines the polymorphic transformation of transparent single crystals of monoclinic red selenium into opaque metallic hexagonal selenium. Using optical polarizing microscopy with controlled heating, microphotography, and Laue X-ray patterns, the author observes nucleation beginning near …
The paper presents the application of the contour integral method to solving mixed problems for a system of differential equations of heat and mass transfer under molecular and molar transport of energy and matter in an arbitrary three-dimensional domain. Furthermore, the contour integral method is …
In the article "Stability of Generalized Processes. I" ("Differential Equations", 1966, No. 7, pp. 872–881), the concept of stability with respect to generalized actions was introduced. The purpose of this article is to present those perspectives on classical stability that served as the starting po…
The paper examines how molecular transport processes, such as heat or concentration diffusion, are modified in turbulent flows when described in variables closer to a Lagrangian representation. It introduces coordinates based on particle labeling at a reference surface and travel time, derives avera…
This paper extends the abstract Noether theory of general singular equations from closed contours to open contours, including equations with Cauchy kernels and discontinuous coefficients. Using a reduction of the Riemann boundary value problem on an open contour to a closed contour and a system of r…
The paper examines the connection between Bohm’s stability criterion for the near-wall plasma layer and the excitation of ambipolar sound in the positive column of a gas discharge in a magnetic field. It argues that violation of the Bohm condition, interpreted as the ambipolar diffusion velocity at …
This note derives an upper bound for the distance between two probability distributions on Euclidean space, defined as the supremum of the absolute difference of their probabilities over all convex sets. Using Fourier inversion, smoothing by an independent random vector with integrable characteristi…
This paper studies Zolotarev stability for segment functionals associated with polynomials of passport [n,n,0] in the critical parameter interval. Using expansions with respect to the nodes of the Zolotarev polynomials, it derives sign conditions on the corresponding loads and proves that, for any f…
This paper analyzes the local expansion of the two-electron atomic wave function near the triple-collision point by introducing a perturbation parameter for the electron-electron interaction. Using Fock’s hyperspherical formulation, it derives perturbation equations for the expansion coefficients an…
This paper investigates the frequency dependence of two-photon absorption in CdS near the fundamental absorption edge at room temperature. The experiment used a Q-switched neodymium glass laser as a monochromatic source and a pulsed xenon lamp with a continuous spectrum, measuring attenuation of sel…
A number of problems in mathematical physics lead to the consideration of divergent integrals. Cauchy and Hadamard developed an algorithm that allows assigning a well-defined finite part to certain divergent integrals. This article proposes a method for introducing the finite part of singular functi…
This paper studies Mal’tsev algebras over fields of characteristic not equal to 2 that satisfy the nth Engel condition, extending results known for Lie algebras. Using identities for Mal’tsev algebras and a series of lemmas on solvable ideals, finite generation, and powers of the algebra, it proves …
This note studies an inverse problem in integral geometry for a two-parameter family of curves in the upper half-plane: to recover a continuous function from its integrals over the curves. Under assumptions of uniqueness of curves through point pairs, nesting of bounded regions, and smooth dependenc…
The paper develops a summation formula for analytic functions with isolated singularities, analogous to the Euler-Maclaurin formula, and uses it to derive convergent series representations for several special functions. The resulting expansions include formulas for the gamma and psi functions with a…
This paper examines the large-time asymptotic propagation of a plane strong detonation wave in a gas at rest when the flow behind the front weakens toward a Chapman-Jouguet wave. Using the detonation jump relations and gas-dynamic equations, it expands the velocity, pressure, and density behind a wa…
This paper presents instrumental work undertaken to refine the seismic microzonation map of Skopje after the 1963 earthquake, for use in reconstruction and urban planning. Using paired seismic stations, one fixed at a reference site and one moved among representative soil conditions, the authors rec…
This note studies double Fourier series of periodic functions in two variables, their conjugate functions and series, and related maximal functions defined through Cesàro means and singular integral truncations. It examines a question of almost everywhere existence for the double conjugate function,…
This paper reports an experimental study of two-photon absorption in CaF2 crystals doped with trivalent holmium ions, motivated by the narrow rare-earth energy levels and the parity-allowed character of optical two-photon electric-dipole transitions. Using ruby and neodymium-glass lasers, the author…
The paper extends the variational method of Goluzin and Kufarev from simply and doubly connected settings to finitely connected circular domains. It first develops a Schwarz-type integral representation for analytic functions in such domains, then uses it to prove differentiability formulas for conf…
The study examines whether hexagonal silicon carbide can grow epitaxially on diamond, a possibility proposed to explain zoning and anomalous birefringence in natural diamonds. Diamond crystals were reacted with pure silicon in vacuum at 1000 to 1550°C and under 60 kbar at 1500 to 1550°C, and the res…
The paper addresses crystal growth at low supersaturation or slight supercooling, where classical two-dimensional nucleation is inadequate and screw-dislocation spiral growth has often been treated as the only viable explanation. It argues, using reported observations of oriented crystallization thr…
This paper studies homogeneous axisymmetric cosmological solutions of the Einstein and Maxwell equations for a perfect fluid with the ultrarelativistic equation of state e equals 3p, extending earlier work on dustlike matter. For vanishing magnetic field, parametric solutions are derived and classif…
The paper studies whether Banach spaces of analytic functions on polydiscs of different dimensions can be distinguished by a finer invariant than linear dimension. It introduces the growth invariant of a linear topological space, based on complemented extension of dual functionals, and applies estim…
