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 examines why rate constants for ionic and ion, molecular reactions often deviate from the linear dependence on reciprocal dielectric constant predicted by simple continuum electrostatic theories. It argues that treating the solvent as a molecular medium, rather than as a homogeneous diele…
This paper generalizes Hilbert’s nonexistence theorem for complete regular surfaces of constant negative curvature in Euclidean three-space. It considers a simply connected complete two-dimensional Riemannian manifold with negative Gaussian curvature satisfying explicit bounds on the curvature, its …
This note studies systems of quasilinear elliptic equations in divergence form on an n-dimensional torus under periodic boundary conditions. Using a Galerkin approximation with trigonometric basis functions and a topological lemma for finite nonlinear systems, it establishes existence of weak soluti…
This paper describes a synthetic route to high molecular weight alpha, omega dicarboxylic acids, specifically 1,14 tetradecanedicarboxylic acid and 1,15 pentadecanedicarboxylic acid. The method uses free radical addition of cyclopentanone or cyclohexanone to undecylenic acid in the presence of tert …
This paper examines whether ordered arrangements of monomer molecules can promote polycondensation, extending earlier observations on ordered systems in polymerization. The authors report the synthesis of high molecular weight, heat resistant polyvinylenes from carbonyl compounds such as acetone, ac…
This paper extends the study of invariant first-order differential systems expressed through exterior differentiation and its metric adjoint beyond previously treated elliptic and hyperbolic cases. It constructs parabolic, semi-degenerate parabolic, and intermediate systems on covariants, relates th…
The paper gives sufficient conditions for the existence of a periodic solution in a nonlinear nonautonomous system of differential equations with a constant linear part and a continuous time-periodic perturbation satisfying uniqueness. It considers the Poincare transformation over one period and com…
This note studies systems of linear differential equations with constant coefficients and the problem of when one operator system is subordinate to another in an \(L_2\) setting on a bounded domain. It proves a necessary and sufficient criterion for subordination, expressed through determinants obta…
This paper studies quasilinear second order parabolic equations in divergence form with many spatial variables, under uniform parabolicity, smoothness, and monotonicity assumptions. It proves a priori bounds and Hölder estimates for solutions and their first time and first and second spatial derivat…
This communication reports electron microscopic observations of morphological polymorphism in crystalline stereoregular polypropylene prepared from very dilute xylene and decalin solutions. High molecular weight polypropylene solutions were heated near the solvent boiling point, slowly cooled, depos…
This paper studies the unsteady boundary-layer flow past a flat plate of a viscous incompressible electrically conducting fluid in a constant transverse magnetic field, assuming negligible induced magnetic field and unit Prandtl number. The magnetohydrodynamic momentum and energy equations are refor…
The study examines the reaction of ortho, meta, and para nitrobenzenediazonium borofluorides with phosphorus trichloride under Doak and Freedman type conditions, focusing on unexpected products formed during attempted synthesis of ortho nitrobenzenephosphonic acid. By varying the ratios of phosphoru…
This note studies directional growth indicators for subharmonic functions of finite order and normal type in multidimensional Euclidean space, extending an analogy with indicators of entire functions. After defining the indicator by radial limiting growth on the unit sphere, the paper records its po…
This note studies weakly infinite-dimensional spaces and transfinite dimension in dimension theory. It extends Hurewicz-type theorems on dimension-lowering mappings to weakly infinite-dimensional bicompact and strongly paracompact spaces, proving criteria under which a space or the domain of a close…
The paper reports a spectropolarimetric study of optical rotatory dispersion in cedrane derivatives, a class for which comparable data were not previously available. Rotatory-dispersion curves were measured in solution for cedrol, primary cedranol, isocedranol, isocedranone, alpha-cedrene, cedrenal,…
This study examines how phosphate and polyphosphate additives affect the solubilizing ability and micellar properties of soap detergent solutions. Using a direct volumetric method, the authors measured limiting solubilization of toluene and heptane in sodium laurinate and sodium naphthenate solution…
This paper investigates the energy distribution of alpha particles produced in the photodisintegration of argon, a reaction whose small cross section had limited earlier measurements. The authors use a multigrid ionization chamber exposed to bremsstrahlung from a 70 MeV synchrotron, with coincidence…
The paper studies coding by discrete devices with finite memory without requiring synchronization between input and output, generalizing usual memoryless coding and finite automaton models. It defines finitely determined operators and finitely enumerable sets of words, relates them to finite-state s…
This paper describes the synthesis of secondary gamma silicon containing acetylenic alcohols by reacting chlorosilanes with dimagnesium bromide derivatives of secondary acetylenic alcohols. The authors prepare trimethylsilyl and triethylsilyl pentynol derivatives and characterize them by boiling poi…
This study examines whether azoferrocene undergoes transformations analogous to the benzidine rearrangement of azobenzene and related intramolecular rearrangements in benzene chemistry. Azoferrocene was synthesized from ferrocenyl lithium and nitrous oxide, then treated with strong acids and reducin…
This paper reports quantitative measurements of the angular dependence of cathode sputtering from the (100) faces of copper and nickel single crystals bombarded by 27 keV singly charged argon ions. Using oriented and annealed single-crystal targets, the authors measured sputtering coefficients as th…
The paper studies two-person minimax games associated with diffusion processes whose drift is modified by competing vector fields subject to local convex constraints. For payoffs given by the expected boundary value plus an additive running functional, the argument connects the value of the game to …
This paper investigates the synthesis of polyacetylene by oxidation of copper acetylide formed from acetylene and divalent copper salts, proposing a mechanism involving polyynes and acetylide intermediates. The obtained black, carbon-rich insoluble product is characterized by elemental analysis, the…
This paper examines whether infrared carbonyl absorption can characterize bond polarization and aromaticity in nonbenzenoid aromatic carbonyl compounds, focusing on tropone, diphenylcyclopropenone, and 3-ethylsydnone. The authors measured the positions and integral intensities of carbonyl bands in l…
This study examines how palladium powder affects the topochemical interaction of hydrogen sulfide with solid acetates of mercury, copper, cadmium, chromium, barium, iron(II), and iron(III). Reaction rates were measured under dynamic conditions at 25 °C from changes in the mass of the solid phase, wh…
This paper examines methods for determining copper in ores at approximately 0.5 percent content with accuracy sufficient to guarantee hundredths of a percent. The authors compare iodofluoride, rhodanide, and gravimetric approaches, considering effects of ore decomposition, titration end points, inte…
This paper investigates collectors for the quantitative coprecipitation of selenium and tellurium at low concentrations, with attention to conditions useful for separation from copper and platinoid metals. Experiments compared ferric, aluminum, bismuth, and cerium ions for selenites and tellurites i…
This study evaluates bog ore from the Rozhdestvenskoye deposit in Tomsk Oblast as an absorbent for fine purification of gas from hydrogen sulfide. The authors characterize the deposit and selected ore samples by chemical and mineralogical composition, then test absorptive capacity using ore based ma…
This study examines the isolation of carbazole from crude anthracene by replacing aqueous formaldehyde with paraformaldehyde in the established conversion of carbazole to soluble 9-oxymethylcarbazole. Enriched anthracene from the Kemerovo coke-chemical plant was treated in ethanol at 80°C with paraf…
The paper studies approximate solution of linear Volterra integral equations of the second kind with smooth kernels and free terms. It adapts Ryaben’kii interpolation formulas based on number theoretic grids, first proving an interpolation error estimate for functions with bounded derivatives of ord…
This study describes the preparation and preliminary characterization of a novolac-type resin obtained by condensing 8-hydroxyquinoline with formaldehyde in the presence of acid catalysts, with the aim of producing polymers containing pincer-like chelating groups. The resin was examined through solu…
This paper examines drill-sample brown coals from the Tugan district of Tomsk Oblast, focusing on their moisture, ash content, density, combustible mass composition, bitumen content, and low-temperature carbonization behavior. The authors relate specific gravity of briquetted dry coal to ash content…
This study examines the reactivity of peat coke intended for metallurgical fuel and gasification applications, with particular attention to the effects of temperature, reagent contact time, and additions of iron ore and limestone flux. Peat briquettes from the Tagan bog were prepared with selected a…
This study examines artificial thermal drying of molded peat intended for metallurgical use, focusing on how flue-gas temperature and heat-carrier velocity affect drying time and mechanical quality. Experiments were conducted at drying temperatures from 80 to 180°C and heat-carrier velocities of 0.4…
This study examines whether iron ore and flux additives can be incorporated into raw molded peat to produce fuel, ore, and slag-forming materials suitable for metallurgical use, especially in low-shaft or oxygen-enriched blast-furnace processes. Experiments mixed Bakchar iron ore or limestone and li…
This paper proposes an indirect method for assessing clay plasticity by measuring the resistance of pressed dry-clay briquettes to washing in moving water. The procedure forms standardized cylindrical briquettes from air-dry, sieved clay, washes them under fixed reciprocating-motion conditions for o…
This study examines how mineralogical composition and calcination temperature affect the extraction of aluminum oxide from clays by hydrochloric acid, and how these factors relate to the pH of clay aqueous extracts. Montmorillonite, kaolinite, and hydromicaceous clays were calcined for one hour at t…
This paper evaluates refractory clays from the Tugan deposit in Western Siberia as a potential local raw material for regional refractory and metallurgical plants. It describes their occurrence as a byproduct of placer concentration and characterizes their color, chemical composition, mineralogy, an…
This study examines the hardening of lime and fly ash binder through X-ray diffraction and electron microscopy, building on earlier chemical and thermal analyses of the same system. The authors compare initial materials, mechanical mixtures, and hardened lime with silica gel or ash after moist curin…
This paper proposes a rapid qualitative method for detecting cadmium ions in the presence of copper ions during hydrogen sulfide scheme analysis. The method relies on quantitative precipitation of copper from weakly acidic sulfuric acid solution with hydrazine sulfate, while cadmium remains in the f…
This paper addresses the analytical difficulty of determining selenium and tellurium in copper electrolysis slimes containing large amounts of copper and noble metals that interfere with common precipitating reagents. The authors develop a gravimetric procedure based on quantitative coprecipitation …
A procedure is described for determining tellurium in tellurate solutions, addressing the difficulty that common reducing agents do not directly precipitate elemental tellurium from tellurates, especially at low concentrations. The authors investigate precipitation by sodium sulfite in moderately ac…
A nephelometric procedure is examined for determining aluminum by precipitation as the sparingly soluble sodium aluminum fluoride compound 11NaF·4AlF3, using the known low solubility of cryolite-type precipitates in excess sodium fluoride. Experiments with aluminum sulfate, chloride, and nitrate sol…
This paper addresses the separation of interfering metals in the photocolorimetric determination of trace cobalt in ores using beta-nitroso-alpha-naphthol. The authors compare alternatives to their earlier cupferron extraction procedure, finding that acetate precipitation and persulfate oxidation we…
The study examines how aqueous nitrates and sulfates of manganese, cobalt, nickel, and copper affect the solubility behavior of silver bromate at 25°C over electrolyte concentrations from 0.001 to 1 mol/l. Using gravimetric and iodometric determinations, the authors measured silver bromate solubilit…
This study examines the reaction of O,O-diethyl chlorothiophosphate with hydrolysis lignin and several lignin derivatives, including nitro, chloro, chloronitro, and alkali-activated forms. The authors treated the lignin materials with alkali, reacted them in dry toluene in the presence of pyridine, …
The study examines how introducing a methyl substituent into the benzene ring affects the catalytic dehydrogenation kinetics of an ethyl side chain, using ethyltoluene conversion to vinyltoluene as the test reaction. Flow experiments on a mixed oxide catalyst measured product formation, hydrogen evo…
This paper describes a direct method for preparing poly(9-vinylcarbazole) from carbazole and vinyl acetate, avoiding separate isolation and polymerization of the toxic 9-vinylcarbazole monomer. The authors carry out the reaction in aliphatic ketone solution at low to moderate temperature using dival…
This study examines the acetylation of 9-methylcarbazole as a route to 9-methyl-3,6-diacetylcarbazole, a potential precursor for divinylcarbazoles and heat-resistant dielectric polymers. Using acetyl chloride in dry benzene with a small amount of acetyl bromide, the authors varied solvent, temperatu…
The paper studies Medvedev’s density relation on subsets of the natural numbers, with emphasis on hyperimmune sets, whose densities are below that of the full set of natural numbers. It characterizes the induced partially ordered structure of density degrees, introduces rarefied and weakly rarefied …
