SovietRxiv · Open Access in English
Rediscovering the Soviet scientific archive, in English
25456 full-text translations 14926 English PDFs 22540 abstracts
Showing 50 of 25456 papers
This paper proves an existence and uniqueness theorem for a multipoint boundary-value problem for a nonlinear system of ordinary differential equations. The argument compares the nonlinear problem with an auxiliary linear system, using a nonsingular change of variables, a matricant, and the associat…
This study examines how methyl substituents affect the reactivity of the ferrocene nucleus in 1,1'-dimethylferrocene, focusing on metallation and Friedel-Crafts acylation. Metallation with n-butyllithium was unsuccessful, whereas n-amylsodium gave mainly dimethylferrocenedicarboxylic acid, indicatin…
This paper investigates the telomerization of methacrylic acid with trialkyl phosphites, extending earlier work on Arbuzov rearrangements induced by unsaturated acids. Experiments with triethyl and tribenzyl phosphites examined the effects of catalyst type, benzoyl peroxide concentration, and reagen…
This note strengthens earlier undecidability results in topology by shifting from homeomorphism of polyhedra to combinatorial questions about complexes. It defines a broad class of binary relations between complexes, lying between combinatorial equivalence and equivalence of fundamental groups for c…
This paper studies approximation and basis expansions for functions analytic in neighborhoods of an arbitrary continuum, extending classical results of Bernstein and Faber beyond level-line neighborhoods. It first proves a factorization and uniqueness result for conformal mappings of doubly connecte…
The paper develops a theoretical treatment of the Faraday effect for Mott excitons of relatively small radius in an isotropic semiconductor. Starting from the exciton Hamiltonian in a constant magnetic field and a monochromatic electromagnetic wave, the authors use perturbation theory in the dipole …
This paper develops a theoretical treatment of the diffusion electric potential generated by a falling electrolyte droplet whose mobile surface carries an adsorption layer of both positive and negative ions. Using electroneutrality in the bulk and at the surface, ion flux balance, and convective dif…
This paper investigates whether electrocapillary motion can displace liquid metal and sulfide droplets in molten metallurgical slags, a possible mechanism relevant to losses of suspended metal droplets. Experiments at 1370 to 1500°C used a magnesia cell containing a CaO, Al2O3, and SiO2 slag and mea…
This note studies when weak local metric or angular conditions on a continuous complex mapping force analyticity. It defines preservation of angles, constant stretching, and an orientation condition at isolated image points, then proves several generalizations of results of Menshov and Bohr: angle p…
This study examines the thermodynamic behavior of solid chromium, iron alloys in relation to phase separation, sigma phase formation, and embrittlement near 475°C. Chromium vapor pressures over alloys containing 21.3 to 75.5 atomic percent chromium were measured between 1100 and 1400°C by the Knudse…
The paper addresses whether every normal topological space can be embedded in a bicompact extension preserving both weight and covering dimension. Using Smirnov’s theory of proximity and uniform spaces, it constructs suitable uniform structures from finite open coverings, with cofinal subfamilies co…
This paper studies boundary-value problems for a quasilinear second-order ordinary differential equation in which a small parameter multiplies the highest derivative. Under smoothness and stability assumptions on the coefficients, it develops asymptotic approximations by combining the degenerate fir…
This paper develops a theoretical treatment of dielectric relaxation when the number of active relaxators, such as orientable dipoles or mobile ions, varies with temperature. Starting from standard Debye-type relaxation formulas, it introduces a thermally activated population of relaxators and deriv…
The study reports precision measurements of the radiation emitted in the decay of terbium-160, produced by neutron irradiation of high-purity terbium oxide. Using a double-focusing spectrometer, the authors measured the continuous beta spectrum, internal conversion electron spectrum, and photoelectr…
This paper examines the influence of sulfate ions on the chloride-induced breakdown of passivity in stainless steels and related metals. Using anodic polarization curves and potential, time measurements at constant current density, the authors show that sulfate additions shift activation potentials …
This paper studies integral representations for functions of two complex variables in bounded complete bicircular domains. It characterizes the domains defined by parametrized boundary radii satisfying specified differential relations, showing that they coincide with bicircular domains with twice co…
The paper addresses uniqueness of generalized solutions to the Cauchy problem for conservative quasilinear hyperbolic systems, a question previously treated mainly for scalar equations or special systems. It proves a uniqueness theorem for piecewise-continuous and piecewise-smooth solutions of two-e…
The paper analyzes the axial compression stability of a hollow cylindrical shell using the mathematical theory of elasticity, following nonlinear elasticity ideas while neglecting rotation components in the equilibrium equations but retaining the deformation of the boundary surface. For an axisymmet…
The study examines the dehydrogenation of unsymmetrical methylisopropylethylene and its mixtures with tetramethylethylene over industrial butylene dehydrogenation catalysts K-12, K-16, and K-18. Products were analyzed by maleic anhydride addition, derivative identification, distillation, and gas-liq…
This study examines the thermodynamics of chlorination and oxidation equilibria for rare-earth and related metal oxides and chlorides in systems containing scandium, lanthanum, neodymium, and samarium. Equilibria of the reaction between solid metal chlorides and oxygen to form solid oxides and chlor…
This paper examines how the distribution of a radioactive microcomponent between a precipitate and solution can be used to determine the composition and stability constants of lead chloride complexes. The authors derive a relation between the distribution coefficient and chloride ion concentration f…
The paper studies a boundary value problem with an oblique derivative for a generalized analytic function in a simply connected domain, reduced by conformal mapping to the unit disk and embedded in a one-parameter family. It transforms the problem into a system for three functions with a boundary co…
The paper studies the asymptotic behavior, as the accuracy tends to zero, of the epsilon entropy of compact classes of analytic functions bounded in a domain and measured on a continuum. For plane continua with elementary nondegenerate neighborhoods, it proves an exact quadratic logarithmic asymptot…
This paper examines the stereochemical requirements for sigma,pi conjugation in bridgehead bicyclic systems, using alpha-chloromercuricamphenilone as a test case. The authors synthesize this compound through peroxide decomposition in the presence of a mercury salt and compare its reactivity with tha…
This note studies uniqueness of limit cycles for nonlinear oscillation equations of Lienard type and related planar systems. It establishes sufficient conditions, involving monotonicity properties of f(x)/g(x), transformed damping functions, and sign conditions at small and large amplitudes, under w…
The paper introduces a new space of nonempty closed subsets of a T1 space, denoted kappa X, with a topology designed to characterize continuous decompositions and mappings of compact Hausdorff spaces more effectively than the usual hyperspace. It establishes basic properties of this space, including…
This paper examines the stereochemistry of vanadyl inner-complex compounds formed with azomethine derivatives of aromatic o-hydroxyaldehydes. Three brominated vanadyl complexes were synthesized, analyzed for composition, and studied by Gouy magnetic susceptibility measurements at room temperature. T…
This study examines intramolecular acylation and cyclization reactions of monosubstituted ferrocene derivatives, extending earlier work on disubstituted ferrocene acids. The authors prepared beta-carbomethoxypropionylferrocene, beta-carboxypropionylferrocene, omega-carboxypropylferrocene, and ortho-…
This study examines the carbon to hydrogen bond distance in crystalline paraffins, where conventional X-ray methods had limited accuracy for locating hydrogen atoms. Electron diffraction data were collected for three paraffin specimens, including C30H62 and C18H38, and Fourier and difference synthes…
This paper examines the difficulty of determining luminosities for hot peculiar stars, focusing on Wolf Rayet stars and white dwarfs, whose spectra and atmospheres make ordinary temperature and luminosity estimates unreliable. For Wolf Rayet stars, it argues that extended envelopes transform high fr…
This paper studies the maximal correlation coefficient for symmetrically distributed pairs of random variables, defining it through the first nontrivial eigenvalue of a normalized symmetric kernel associated with the joint density. It gives the corresponding variational characterization, describes a…
This paper develops a framework for homogeneous difference schemes for linear differential equations with variable coefficients, emphasizing convergence and accuracy uniformly over specified coefficient classes. It introduces definitions of convergence, approximation order, equivalence, symmetry, an…
This paper studies axisymmetric supersonic gas flow past a body of revolution using the characteristic form of the governing equations. It derives an evolution equation along characteristics for the derivative of the Mach angle function and relates its boundary condition to the radius of curvature o…
This paper reports a simplified synthesis of 4-substituted 1-azadehydroquinolizinium salts, extending earlier work that required preparation and acid cyclization of condensation products from 2-aminopyridine and acylacetaldehyde acetals. The authors show that direct condensation of 2-aminopyridine w…
This paper gives necessary and sufficient criteria for boundedness on the half-axis of solutions to linear differential equations with delayed argument, including variable delays and equations with both delayed and nondelayed terms. Working in Banach spaces, it formulates boundary-value problems wit…
This note studies lower bounds for the best uniform approximation of classes of differentiable and analytic functions by quotients of finite parameterized sums, including rational-type expressions. Using previously established entropy estimates, it derives inequalities for Hölder differentiable func…
The study examines the gas phase interaction of ozone with methyl hydroperoxide, motivated by observed losses of methyl hydroperoxide during methane oxidation experiments in which undecomposed ozone was present. Methyl hydroperoxide was synthesized and reacted with excess ozonized oxygen in a thermo…
This paper studies the steady flow of an ideal incompressible heavy fluid of finite depth past a submerged hydrofoil, formulated as a nonlinear free boundary problem with a free surface and bottom boundary. Using an inverse method, the physical flow domain is conformally mapped to a strip, the hydro…
The paper studies Cauchy problems for linear differential systems of infinite order with constant coefficients and applies these results to linear partial differential equations of infinite order. It reduces an infinite system of order m to a first order matrix equation, represents the formal soluti…
This study examines how nitro and amino substituents influence one another when separated by two benzene rings connected through oxygen or sulfur bridges, in comparison with directly linked biphenyl systems. The authors use kinetic measurements of acylation with p-nitrobenzoyl chloride in benzene, d…
This study examines how etherification affects the hydrophilicity of cellulose materials, using heats of wetting by water as a quantitative measure. Methylcellulose, ethylcellulose, and oxyethylcellulose prepared from cotton linters, along with methylcellulose from viscose silk, were measured in an …
This paper studies the large-time behavior of solutions to the Cauchy problem for a scalar quasilinear parabolic conservation law with viscosity and for the corresponding first-order conservation law, under bounded measurable initial data with prescribed limits at spatial infinity. Using comparison …
This paper develops an approximate microscopic theory of the phase transition in a weakly interacting nonideal Bose gas using a model Hamiltonian that retains two-index interaction terms and includes Bogolyubov’s superfluidity Hamiltonian as a limiting case. Applying a canonical Bogolyubov transform…
The paper analyzes local stresses in a circular prismatic bar subjected to transverse bending and weakened by an eccentric longitudinal elliptical cavity. Using complex-variable methods in elasticity, the elliptical boundary is mapped to a circle, boundary conditions are transformed into functional …
This paper reports an experimental study of resonance scattering of 1.37 MeV gamma quanta from the decay of sodium-24 by magnesium-24 nuclei, aimed at determining the lifetime of the first excited state of magnesium-24. Because recoil losses exceed the natural level width, the experiment uses radioa…
This paper studies the synthesis of circuits realizing Boolean functions by applying nonsingular linear transformations of variables over the field with two elements. It defines equivalence classes of Boolean functions under these transformations, uses Pólya’s method to enumerate classes for small n…
This study extends hydrosilane addition chemistry to allyl ethers of 1,1,2-trifluoro-2-chloroethanol and 1,1,2,2-tetrafluoroethanol in order to prepare previously undescribed fluorosilicon-organic ethers and compare hydrosilane reactivity. Using platinized carbon catalysis in heated autoclave reacti…
This paper studies Chebyshev approximation of continuous functions on a compact set with values in a Hilbert ring by functions of the form given by left multiplication by an arbitrary ring element and a fixed function. Using a more general framework of approximation by operator functions in Hilbert …
