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 note studies the quickest detection of a change in a continuously observed Gaussian process whose drift switches at an unknown time, under constraints on the frequency or probability of false alarms. It formulates several versions of the problem, including Bayesian models with an exponential pr…
This paper develops an elimination method for linear programming problems formulated as systems of linear inequalities in a real linear space, allowing both non-strict and strict inequalities. It defines convolutions with respect to subspaces or sets of unknowns and proves consistency criteria: a sy…
This note gives internal characterizations of topologically complete spaces in the sense of E. Čech, where a completely regular space is complete if it is a G-delta subset of its Čech compactification. It introduces the notion of a diameter on a space, defines complete diameters through centered shr…
This paper examines scaling properties and asymptotic behavior in the problem of a point explosion in an ideal two-parameter compressible medium. Using dimensional analysis of the governing equations, shock conditions, and the general form of the internal energy, it determines when a solution comput…
This paper develops a theory of current, time curves for irreversible anion reduction at a dropping mercury electrode in the presence of an adsorbing catalytic species, with explicit allowance for concentration polarization. Starting from convective diffusion near an expanding spherical electrode an…
The paper studies trace properties of functions in weighted first order Sobolev classes on a half-space, where each first derivative is integrable with a possibly different power weight degenerating at the boundary. It establishes a direct trace theorem identifying the boundary values as elements of…
This paper reports the growth and characterization of barium titanate based ferroelectric single crystals containing small additions of barium hafnate, prepared from a potassium fluoride flux in platinum crucibles. The authors examine dielectric permittivity, field dependent nonlinearity, bias field…
This study addresses the unresolved structure of the peptide portion of ergoalkaloids by developing synthetic routes to model tripeptides that reproduce the amino acid sequence of ergotamine and related analogues. Using N-benzoyl-alpha-benzyloxy-alpha-amino acids, the authors prepared racemic and op…
The paper examines how to construct scattering matrices for nonlocal quantum field theories while retaining the graph technique of local perturbation theory. It argues that nonlocality can be introduced by modifying chronological contractions, and hence internal lines of Feynman graphs, without chan…
This paper examines whether the inhibition limit in thermal cracking of alkanes is independent of inhibitor identity, a question bearing on whether the residual reaction is molecular, heterogeneous, or radical-chain in character. Reviewing earlier interpretations and experimental findings, it tests …
This paper examines oxidation, reduction, and disproportionation reactions of polyfluorinated aliphatic nitroso compounds, with particular attention to trifluoronitrosomethane. The authors compare behavior in acidic oxidizing media, alkaline aqueous solution, and nonaqueous reactions with nucleophil…
The paper studies polynomial ideals in complete spaces of infinitely differentiable functions with prescribed polynomial growth, motivated by solvability and homogeneous solution problems for constant coefficient partial differential equations in spaces of slowly increasing functions or functionals.…
This paper develops a theory of radicals for group pairs, where one group acts by automorphisms on another. It defines abstract properties of group pairs, associated theta-radicals in the acting group and in the domain of action, and studies locally stable and locally theta elements under closure co…
This paper examines whether radioactivity in soil and plant samples from the Tunguska catastrophe region can be connected with the 1908 explosion, using field radiometry, laboratory beta-radiation studies, comparisons with samples from the Urals and Siberia, and measurements across tree annual rings…
This study examines whether the autooxidation rate of natural fat triglyceride mixtures is governed simply by unsaturation as measured by iodine number. Using pork fat samples prepared under nitrogen, the authors determined iodine and thiocyanogen numbers, calculated the average molecular weight per…
This paper argues that the known uranium oxides can be interpreted as members of a homologous series with the general composition U_nO_2n+2, analogous to homologous regularities previously identified in transition metal oxides. Reviewing reported chemical and crystallographic data, it assigns the fi…
This paper investigates the aqueous system of copper arsenate, sodium carbonate, and water at 50 degrees C, treated as a ternary approximation to a reciprocal quaternary salt system because of the low solubility of the copper salts. Using an isothermal solubility method, chemical analysis of liquid …
For each prime number q, the paper constructs a class of three-dimensional compacta P3(q) as inverse limits of polyhedra obtained by controlled tube identifications generalizing Pontryagin’s compactum P2(q). It analyzes their homological and cohomological dimensions with several coefficient groups, …
The paper studies the absolute minimum of an integral functional over piecewise smooth curves whose derivative is constrained through a parameter with bounded range. By transforming the independent variable along extremal boundary families, the problem is reformulated in terms of generalized lines w…
This paper investigates the thermal expansion of water confined in glass microcapillaries with radii comparable to the presumed thickness of boundary liquid layers. A method is described for measuring capillary radius and water-column elongation by optical observation of the meniscus, followed by te…
This study examines the polymerization and copolymerization of styrene, butadiene, and isoprene initiated by lithium ethyl in hydrocarbon and electron-donor media, including toluene, triethylamine, ether, dioxane, and tetrahydrofuran. Kinetic measurements, molecular-weight data, spectrophotometric d…
This note studies rearrangements of Fourier series with respect to the Haar system, general bases in L2, and orthonormal complete systems, focusing on almost everywhere divergence and nonsummability under arbitrary summability methods. It introduces property D for series whose terms can be rearrange…
This paper derives linearly enveloping coupler curves for a general four-link ellipsograph whose sliders move along guides at an arbitrary fixed angle, and for an inverse ellipsograph mechanism. Using instantaneous centers of rotation, perpendicular projections, and parametric equations for the corr…
This study examines how spinel structure affects the catalytic behavior of normal CoMn2O4 and inverse MnCo2O4 in the deep oxidation of propylene. Reaction rates were measured under static conditions from 200 to 350 °C, with attention to the effects of carbon dioxide removal, reactant pressures, oxyg…
This paper develops a simplified hydrodynamic theory of atmospheric fronts separating cold and warm air masses, extending earlier work on frontal surfaces. Under assumptions of hydrostatic balance, small pressure and temperature perturbations, turbulent viscosity, two-dimensional stationary motion i…
The paper establishes existence and uniqueness results for the first boundary value problem for a one dimensional quasilinear parabolic equation with coefficients depending on time, space, the solution, and its spatial derivative. It weakens earlier growth assumptions on the ratio of the lower order…
This paper generalizes the Cantor-Hausdorff completion process beyond metric and uniform spaces by introducing Cauchy directions, defined through primary ideals of an open base in a regular Hausdorff space. It develops basic convergence properties of these directions and proves that suitable equival…
This note studies semigroups through order-theoretic properties of their lattices or posets of subsemigroups, distinguishing between the ordinary subsemigroup structure and the version enlarged by the empty set. It gives structural characterizations for semigroups whose subsemigroups are linearly or…
This note studies infinitesimal rigidity of closed surfaces with positive extrinsic curvature in Riemannian spaces, focusing on surfaces not homeomorphic to the sphere. For a surface homeomorphic to a torus, the argument uses conformal coordinates associated with the second quadratic form, passes to…
This paper extends the mathematical theory of steady combustion of condensed substances from the high pressure regime, where gas phase heat release dominates, to low pressure powder combustion. It formulates a three stage diffusion thermal model for condensed phase decomposition, incomplete gas phas…
This study examines how adsorption on a 1 percent platinum on carbon catalyst relates to the catalytic addition of selected alkyl and chloroalkyl silicon hydrides to unsaturated fluoroalkyl allyl ethers. Adsorption isotherms at 20 °C were measured in a flow apparatus, saturated vapor pressures were …
This study examines the mechanism of hydrogen redistribution during the transformations of cyclohexene and 1,3-cyclohexadiene on platinum films at 20°C. Using measurements of hydrogen evolution or absorption together with changes in the electrical conductivity of the films, the authors compare condi…
This paper studies linear differential expressions with polynomial coefficients whose order is reduced by the generalized differentiation operator with Euler Cauchy kernel. Under regularity conditions making infinity a regular singular point, the authors derive algebraic conditions on the transforme…
This paper gives an invariant construction of spaces with centro-projective connection from a third-order differential neighborhood using Cartan’s exterior differential equations for the prolonged pseudogroup of analytic transformations. It represents such a space as an n-dimensional submanifold in …
This note introduces isotropic flows, a class of tangent dynamical systems on spaces of frames over a Riemannian manifold in which the speed is constant and the curvatures of trajectories depend only on the base point. It proves that such flows preserve the natural measure on the frame space, relate…
The paper extends a classical existence criterion for meromorphic functions on a closed Riemann surface with prescribed principal parts to quasianalytic functions satisfying a first order elliptic equation. Using periods of complex normalized quasianalytic differentials and residue computations over…
This paper develops a local differential-geometric theory for a pair of second-order ordinary differential equations on the plane under arbitrary analytic point transformations. Using Cartan-type frame canonization for the representation space of the infinite transformation group, it constructs inva…
This study examines how the structure of diacyl peroxides of paraffinic and phenylcarboxylic acids affects their thermal stability and initiating activity in polymerization. A series of synthesized peroxides was tested by measuring decomposition rates in ethylbenzene, polymerization rates of styrene…
This paper studies local geodesic surfaces in a 2n-dimensional manifold equipped with a complex structure and a torsion-free almost complex affine connection. Using adapted frames and complex differential forms, it relates analytic real submanifolds of the manifold to complex analytic submanifolds o…
This paper identifies a class of quasilinear systems written in divergence form through derivatives of generating functions and shows that it includes several equations of mathematical physics, including variational Lagrange equations, crystal optics, and gas dynamics. The author gives explicit redu…
This note develops a formulation of asymptotic methods for nonlinear oscillations based on separating motion into fast unperturbed dynamics and slow evolutionary dynamics. For perturbed systems with a small parameter, it derives a necessary and sufficient commutation condition for exact separation a…
This note studies Paley-Wiener type questions for the Hilbert space of Fourier transforms of square integrable functions on a bounded domain, focusing on when integration over a measurable subset of frequency space defines a norm equivalent to the usual \(L^2\) norm. It introduces a quantity measuri…
This paper generalizes experimental data on the influence of heated channel length on critical heat flux during forced flow of steam, water mixtures and related fluids in tubes and annular channels. Using previously proposed dimensionless similarity criteria, the authors process data for short heate…
This paper develops a method for relating the fluctuation spectrum of a detected radar signal to the motion of scatterers in meteorological objects, including particles with nonuniform sizes and reflectivities. Starting from the field of an ensemble of moving scatterers, the authors derive expressio…
The paper develops an asymptotic treatment of scalar diffraction by an elliptic cylinder, with extensions to an ellipsoid of revolution, in the high-frequency regime when the eccentricity may approach unity. For the Dirichlet problem on an elliptic cylinder, the Green function is represented through…
This paper studies inverse spectra and their relations to dimension theory, especially polyhedral, simplicial, and combinatorial spectra and the dimensions of their limit spaces. It gives criteria for an inverse spectrum of compact spaces or finite complexes to have a limit of covering dimension at …
The paper develops a construction representing compact topological spaces as limits of direct spectra of finite discrete sets, in contrast to the standard inverse spectrum representation. It defines spectra equipped with a proximity relation, constructs threads and pencils, and shows that these dete…
This study investigates surface tension at the interface between two coexisting gas phases under high pressure, using the helium, ethylene system at 13, 16, and 18 degrees Celsius. Phase compositions and densities were measured after intensive stirring, and interfacial tension was determined by a ca…
This letter examines a claimed generalization of Voronoi’s normal basis for cubic fields to algebraic fields of arbitrary degree. The authors identify an error in B. Epelbaum’s proof, arguing that the relevant systems of equations do not yield the asserted additional relations because their independ…
