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 reports a route completing the synthesis of the alkaloid yohimbine from yohimbon, addressing the difficulty of converting earlier synthetic intermediates into the natural methyl ester. Yohimbon is condensed with diethyl carbonate to give ethyl yohimboncarboxylate, which is then catalytica…
This paper reports the isolation and identification of beta-butylthiophane, a cyclic sulfide, from oil of the coal-bearing series of the Tuimazy field. The authors fractionated the oil by vacuum isothermal rectification, enriched sulfur-containing components through repeated silica-gel chromatograph…
This article considers the problem of placing an artificial Earth satellite into orbit. It is assumed that insertion is carried out by means of a rocket booster consisting of one or several stages. The study investigates what the law of variation over time of the thrust direction of the jet engines …
This paper examines the use of the emanation method for studying topochemical transformations relevant to the preparation of oxide catalysts, focusing on the decomposition of magnesium and zinc hydroxides and carbonates. Radium labeled precipitates were prepared, calcined under controlled conditions…
This paper derives formulas for the diffusional deposition of aerosol particles on a circular cylinder placed perpendicular to a flow, focusing on the limiting case of small capture coefficients. Using the convective diffusion equation and Levich’s method in streamline coordinates, the author obtain…
This study examines the conditions under which aromatic amines add to acrylonitrile to form beta-arylaminopropionitriles. Contrary to earlier observations that the reaction does not proceed without acidic catalysts in anhydrous media, experiments showed that heating aniline and substituted aromatic …
This note studies spectral properties of semibounded self-adjoint elliptic differential operators on the whole space, including strongly elliptic systems with bounded smooth coefficients. Using estimates for the Green function of the associated parabolic Cauchy problem, it proves an \(L^2\) bound fo…
This paper studies the minimum number of distinct negated subformulas needed to realize Boolean functions and systems of Boolean functions by formulas over conjunction, disjunction, and negation. It defines inversion complexity for formulas and function systems, introduces alternating chains in the …
This paper studies a finite difference method for a mixed initial boundary value problem for equations of S. L. Sobolev type, involving a second time derivative applied to an elliptic spatial operator. A grid analogue is constructed, and energy estimates are derived to prove weak convergence of the …
This paper develops an abstract notion of Lyapunov norm on a linear set, defined by order-valued homogeneity and ultrametric-type subadditivity conditions. It establishes basic properties of such norms in finite-dimensional subspaces, including the existence of a specially adapted basis whose linear…
This paper examines the problem of long-range precipitation forecasting for the virgin lands of Western Siberia and Kazakhstan, where growing-season rainfall varies sharply between droughty and well-moistened years. It proposes an index of the cyclonic or anticyclonic character of prewinter meridion…
This paper examines regularities in the diffusion combustion of liquid petroleum products, including gasoline, kerosene, diesel fuel, solar oil, and transformer oil, burned in cylindrical reservoirs of widely varying diameters. Using flame photography, burning rate measurements, flame height data, a…
This note addresses the stability restrictions that make explicit grid methods inefficient for parabolic boundary value problems and the algebraic burden of fully implicit schemes. It proposes iterative difference schemes that use spectral properties of the discrete operator to suppress high frequen…
This paper investigates isomeric silapentanes with the formula C4H12Si in order to assess how the position and bonding state of silicon in a silicon-carbon skeleton affect physical properties and Si-H reactivity. The authors develop aluminum chloride catalyzed synthetic routes, including disproporti…
This paper investigates the previously uncertain 5.5-hour palladium activity produced in neutron reactions and tests whether it should be assigned to the nuclear isomer Pd-111m. The authors develop a radiochemical isomer-separation procedure based on the Szilard-Chalmers effect, using palladium sali…
This study examines whether sulfur affects the solubility of oxygen in liquid iron, a question relevant to understanding simultaneous deoxidation and desulfurization processes. Electrolytic iron melts containing sulfur were equilibrated at 1550 and 1600°C with a steam and hydrogen gas mixture, using…
This paper develops a theory of gas flow through highly porous bodies in the transition between Knudsen and viscous behavior, focusing on a proposed pseudomolecular regime in which intermolecular collisions are frequent relative to wall collisions but particle dimensions remain small compared with t…
This study examines the vapor-phase oxidative transformations of methanol, formaldehyde, and formic acid over granulated tin vanadate under flow conditions with excess moist air. Product analyses showed that methanol and formaldehyde give mainly formaldehyde, carbon monoxide, and smaller amounts of …
This note computes matrix elements of irreducible unitary representations of the three-dimensional Euclidean motion group using an integral method, complementing earlier infinitesimal calculations. The authors express the translation matrix elements through integrals of rotation-matrix functions, de…
The paper studies the spectral effect of adding a continuous potential perturbation tending to zero at infinity to a closed differential operator of Schrödinger type in \(L_2\) over Euclidean space. It proves that, for every point in the resolvent set of the unperturbed operator except possibly a co…
The paper studies how the largest characteristic exponent of a linear nonautonomous differential system can change under small nonlinear perturbations satisfying a Lipschitz bound. It defines a quantity Omega from bounds on the fundamental matrix of the unperturbed system and proves that, for suffic…
This paper studies oscillation and nonoscillation criteria for solutions of the second order linear equation y'' + p(x)y = 0 on a half-line. Using Riccati-type inequalities involving auxiliary differentiable functions r(x), it derives several sufficient conditions for nonoscillation and oscillation,…
This paper analyzes how a small bluntness at the leading edge of a thin airfoil or wedge can alter high supersonic flow over distances much larger than the bluntness size. The effect of the blunt edge is modeled as a concentrated force at the leading point, and the steady aerodynamic problem is redu…
This study examines the structure of humic acids obtained by mild oxidation of Donets hard coals of different metamorphic ranks with hydrogen peroxide or nitric acid, followed by alkaline extraction. Optical density measurements, calcium chloride precipitation thresholds, infrared spectroscopy, and …
This paper reports experiments on delayed X-ray emission from powerful pulsed discharges in xenon and in hydrogen, xenon mixtures, distinct from the initial breakdown radiation. Using a large porcelain discharge chamber driven by a 36 microfarad capacitor bank, with current, voltage, film, and scint…
This paper develops a thermodynamic treatment of binary solid solutions that are nearly completely ordered at temperatures well below the order disorder transition. For compositions close to stoichiometric, the free energy is expanded in terms of the small concentrations of atoms occupying foreign s…
This paper examines how the vertical turbulence coefficient in the sea depends on wind speed and on parameters of surface waves. Using hydrological, current, actinometric, and meteorological observations from anchored stations aboard the expedition vessel Yulii Shokalskii in 1954 to 1955, the author…
This paper determines the range of the functional f(z0)/F(zeta0) for pairs of non-overlapping simply connected domains, where f maps the unit disk onto a domain containing 0 and F maps the exterior disk onto a domain containing infinity. Using Goluzin’s variational method, the author derives extrema…
This study investigates the mechanism of welding organic glass, specifically plasticized and unplasticized polymethyl methacrylate, in relation to theories of adhesion and autohesion. Using controlled welding experiments with varied pressure, temperature, and time, followed by tensile testing of wel…
This paper examines the condensation of nitroolefins with compounds containing active methyl groups, extending earlier work on reactions with active methylene compounds. Nitroisohexylene, nitrostyrene, and furyl nitroethylene were reacted with trinitrotoluene, mesomethylacridine, and quaternary salt…
This note studies groups in which every conjugacy class is finite and gives structural criteria for such groups in terms of locally normal and torsion-free central components. It proves that a torsion-free group whose quotient by its center is locally finite must be abelian, and uses this with Dietz…
This paper examines nonstationary effects during the anodic dissolution and electropolishing of copper in concentrated orthophosphoric acid, focusing on potential jumps and maxima in current, voltage curves. Treating mass transport near the anode as predominantly diffusional in highly viscous acid s…
This note studies a mixed initial boundary value problem for a second order hyperbolic integro-differential equation with measurable elliptic spatial coefficients, lower order terms, and integral terms involving the unknown function and its time derivative. Using expansion in generalized eigenfuncti…
This paper studies local representation of solutions to the Euler Poisson Darboux equation near the symmetry axis, extending a known integral representation involving an analytic function of one complex variable. For domains adjacent to an interval of the axis and satisfying a vertical convexity con…
This study examines the alkylation of benzene with propylene using phosphoric acid derivatives containing fluorine, their boron fluoride complexes, and sulfuric acid as comparative catalysts. Experiments at mainly 20°C evaluated catalyst durability, alkylate yield, product fractionation, benzene to …
This paper studies boundary-value problems for elliptic systems of differential equations in the plane, including higher-order systems with nonlocal boundary terms. The problem is reduced, using Sobolev’s integral identity, to a first-order elliptic system with an integral term, then analyzed throug…
This study examines how supersaturation kinetics govern the development of crystallization structures during the hydration hardening of gypsum. Using conductometric measurements of calcium sulfate concentration in hemihydrate suspensions, the authors show that sufficiently concentrated systems reach…
A photographic emulsion stack irradiated at high altitude was examined for strange-particle interactions, and a stopping negative kaon event with subsequent hyperfragment emission was analyzed. Range, ionization, scattering, angular, and kinematic measurements of the primary and secondary stars iden…
This study examines the origin of curved, wavy glide lines formed during plastic deformation of silver chloride crystals, a material whose mechanical behavior is closely analogous to that of metals. Polycrystalline plates, recrystallized from pressed and rolled single crystals, were stretched while …
This paper formulates and solves a self-similar problem for a strong spherical point explosion in a perfect gas with heat conduction, neglecting the initial pressure and assuming a thermal conductivity proportional to the square root of temperature. The gas-dynamic equations, an energy integral, sho…
The study investigates the direct liquid-phase photochemical sulfooxidation of n-heptane with gaseous sulfur dioxide and oxygen under ultraviolet irradiation. Experiments in quartz reactors and flow and closed systems showed formation of products consisting mainly of heptanesulfonic acids, with smal…
This paper reports an improved Friedel-Crafts alkylation of ferrocene that avoids using a large excess of alkyl halide by employing n-heptane or petroleum ether as solvent. Ferrocene was alkylated with methyl chloride, ethyl bromide, isopropyl chloride, and ethylene-derived conditions, followed by f…
This study reports the synthesis and biological screening of diphenyl derivatives designed as potential antitubercular agents, focusing on azomethines and N,N′-substituted thioureas derived from 4-aminodiphenyl and related para-alkoxy compounds. The authors prepared multiple series by condensation w…
This paper reports the thermal reaction of methyldichlorosilane with ethylene and propylene under pressure and excess olefin, in the context of known additions of silicon hydrides to olefins. The authors show that these reactions form homologous mixtures of methylalkyldichlorosilanes, identified as …
