Translated papers from the Chinese Preprint site, Chinaxiv
Showing 50 of 15526 papers
Generated abstract This paper examines how crystal habit may be related analytically to the pressure and temperature conditions of growth, using diamond crystals as the principal example. It proposes a thermodynamic approach in which the numbers of faces and vertices of a convex crystal polyhedron are treated as addit…
Generated abstract The paper studies the decoding of finite Mealy automata treated as black boxes when no upper bound on the number of states is available, focusing on what can be achieved by simple experiments rather than multiple branching experiments. It formalizes decoding algorithms, introduces a uniform frequenc…
Generated abstract The paper studies error estimation for finite difference solutions of the Dirichlet problem for the Laplace and Poisson equations in a bounded plane domain. It derives weighted a priori estimates for the grid solution and for difference approximations to derivatives of arbitrary order, with dependen…
Generated abstract The paper constructs several compact Hausdorff spaces for which the covering dimension and the small and large inductive dimensions do not coincide. Using modified topologies obtained by replacing points of the square with circles or previously constructed compacta, it gives examples with dim equal …
Generated abstract This note studies a form of modeling finite pseudo-Boolean algebras by systems of arithmetical formulas under Kleene realizability, in connection with realizability of propositional formulas and intuitionistic arithmetic. It defines when such a system models an algebra, proves by induction that alge…
Generated abstract This paper reports a computational verification of Fermat’s Last Theorem for all odd prime exponents below 5500 using Vandiver’s criterion for irregular primes, together with Kummer’s result for regular primes. Computations on the BESM-6 computer rechecked earlier SWAC results below 4002, extended t…
Generated abstract This note studies sequential estimation for scalar parametric families, comparing non-Bayesian sequential plans with fixed-sample Pitman estimation under constraints on expected sample size. Under smoothness assumptions expressed as absence of discontinuities in information quantities, the authors s…
Generated abstract This paper studies the stability of relaxation processes for minimizing a differentiable functional on a convex domain in a real Hilbert space under strong monotonicity and Lipschitz type bounds on its derivative. It analyzes perturbed iterations with additive noise, measuring perturbations first by…
Generated abstract The paper examines the limiting case of separating a crystallographic basic point system from its vector system when the selected vector peak has multiplicity two in the Fedorov group P1. It argues that when two pairs of points in the basic system define equal vectors, the corresponding vector syste…
Generated abstract The paper applies a spin-dependent version of the factorizing quark model to high-energy production processes in which a pseudoscalar meson and proton produce a vector meson and a positive-parity baryon. It argues that, although quark spin-flip amplitudes are small relative to the main quark scatter…
Generated abstract This note proposes a real analogue of Pyatetskii-Shapiro’s construction of Siegel domains, defined from a vector space with involution, a homogeneous convex cone, and a definite Hermitian bilinear mapping. It proves that homogeneous Siegel domains are affinely homogeneous, then specializes the const…
Generated abstract This paper examines how shear stresses affect the acoustic parameters of longitudinal and transverse elastic waves in rock samples, a topic for which little experimental evidence was available compared with compression studies. Cylindrical samples of granite, sandstone, and marble were subjected to …
Generated abstract This paper develops a generalization of Mindlin’s method for elasticity problems in a half-space by using analytic continuation of elastic solutions through a plane boundary. It formulates reflection laws for body forces that allow boundary-value problems with either vanishing displacements or vanis…
Generated abstract This note studies covering problems for plane analytic sets in Baire space whose vertical sections satisfy a hereditary property. Using Lyapunov’s general theorems on multiple separability, it gives a construction that covers an analytic set, or the relevant sections of such a set, by a Borel or coa…
Generated abstract The paper studies the analytic structure of Hilbert subspaces generated by homogeneous random fields on Euclidean space, reducing the problem through the spectral representation to weighted spaces generated by exponentials over bounded parameter sets. For rectangular sets, it gives sufficient logari…
Generated abstract This note examines the gravitational collapse of a mass with small axial deviations from spherical symmetry, focusing on the behavior of nonspherical metric perturbations near the gravitational radius. Using a linear perturbation of the Schwarzschild metric, expansion in generalized spherical functi…
Generated abstract This paper formulates Petrov’s algebraic classification of gravitational fields in chronometrically invariant terms for a fixed reference system in general relativity. Using an orthonormal frame, it expresses the Weyl tensor through three-dimensional chronometrically invariant tensors and represents…
Generated abstract The paper studies a boundary value problem posed by A. V. Bitsadze for the three-dimensional Lavrentiev-Bitsadze equation, which is elliptic in one half-space, hyperbolic in the other, and degenerates on the separating plane. For a bounded domain bounded partly by characteristic cones, it introduces…
Generated abstract This note states and outlines a proof of a rigidity theorem for compact manifolds of constant negative curvature: if two such manifolds of dimension at least three have isomorphic fundamental groups as abstract groups, then they are isometric. The argument equips the common finitely generated group …
Generated abstract This paper studies homogeneous generalized functions on the space of rectangular matrices over a non-discrete locally compact disconnected field, focusing on the analytic family defined by powers of the maximal norm of the maximal minors. It determines the poles and residues of these generalized fun…
Generated abstract The paper develops a regularizer for pseudodifferential Cauchy problems with complex symbols and for multilayer difference schemes, using bicharacteristics and a canonical operator on a Lagrangian manifold with a complex germ. It proves existence, uniqueness, and propagation of smoothness for a clas…
Generated abstract This paper constructs a compactification of a noncompact symmetric Riemannian space using admissible projective representations of its motion group. Starting from the root system and lattice of the space, it defines a family of boundary, or epsilon, spaces associated with admissible tuples in Cartan…
Generated abstract The paper studies two singular integral operators on rectifiable Jordan curves and associated nonlinear integral equations in subspaces of Lp characterized by modulus of continuity conditions. It derives norm and continuity estimates, including analogues of Zygmund type inequalities, under generaliz…
Generated abstract This paper studies the large-time asymptotic behavior of solutions to the exterior Neumann boundary-value problem for the two-dimensional wave equation outside a convex contour with positive bounded curvature. The solution is decomposed into a free Cauchy-wave part and a correction term, whose Lapla…
Generated abstract This paper examines nonstationary finite-amplitude wave propagation in nondispersive dissipative media, focusing on plane and cylindrically symmetric acoustic, and by analogy magnetoacoustic, disturbances. By applying self-similar substitutions, the governing nonlinear partial differential equations…
Generated abstract The crystal structures of ammonium bis(dimethylglyoximato)bis(selenocyanato)cobaltate(III) trihydrate and the corresponding thiocyanato compound are determined and compared. X-ray diffraction data, Patterson and electron-density maps, and least-squares refinement establish monoclinic P21/n cells wit…
Generated abstract This paper studies the existence of values in differential pursuit games in Euclidean space, where two players choose measurable controls under standard continuity, Lipschitz, compactness, and growth assumptions. It defines piecewise-programmed strategies and examines three payoff types: terminal di…
Generated abstract This paper studies probabilistic properties of pairwise Hamming distances among a random subset of vertices of the n-dimensional unit cube, where vertices are chosen with independent Bernoulli coordinates. For prescribed distance intervals, it analyzes the counts of pairs whose distances fall in eac…
Generated abstract This paper studies fundamental systems of functions for the Beltrami operator on a Riemannian domain, a framework that includes trigonometric systems and eigenfunctions of elliptic boundary value problems without imposing boundary conditions. It proves a mean value formula for regular solutions of t…
Generated abstract The note studies space complexity analogues of known undecidability results for algorithmic problems in finitely presented groups and semigroups, especially word, conjugacy, and individual conjugacy problems. By refining constructions of Bokut, Collins, and Shepherdson and estimating the associated …
Generated abstract The paper develops a generalized form of Lyapunov’s second method for systems with small perturbations, including stability with respect to only part of the variables in the neutral case. It replaces standard definiteness requirements on a Lyapunov function and its derivative by conditions involving…
Generated abstract This paper examines relations among topological entropy, Kolmogorov epsilon entropy, and metric entropy for homeomorphisms of compact metric spaces. It proves that topological entropy can be obtained as the limiting growth rate of the epsilon entropy of orbit metrics, and establishes, for compact me…
Generated abstract The paper studies equivalence relations among absolute bases in Köthe spaces, focusing on when bases are equivalent up to isomorphism, scalar multiplication, and permutation. It introduces the multiplicity of a basis as the minimal number of regular subsequences needed after permutation, defines Ris…
Generated abstract This note studies the boundary behavior of regular solutions to uniformly elliptic second order equations in bounded domains whose boundary points admit inner or outer contact by generalized paraboloids. Using barrier constructions and assuming the maximum principle, it establishes lower estimates n…
Generated abstract This note formulates the approximate solution of nonlinear operator equations in Banach spaces as a controlled process in which different iterative methods are switched according to an admissible control. It introduces optimization problems that seek either the best accuracy under a cost bound or th…
Generated abstract This paper studies the unsteady magnetohydrodynamic flow of a supersonic electrically conducting ideal gas in a plane dielectric channel as it enters or exits a nonuniform transverse magnetic field. The authors formulate the coupled gas-dynamic and electrodynamic problem for finite magnetohydrodynam…
Generated abstract This study examines how ion species and irradiation dose affect the crystallization of amorphous silicon dioxide films during subsequent annealing. Films deposited from tetraethoxysilane in an argon oxygen plasma were irradiated with 50 keV argon, phosphorus, or boron ions over a range of doses, ann…
Generated abstract This note studies the existence of Poisson-stable solutions for differential equations in Banach spaces, allowing nonunique solutions and without assuming global solvability for all initial data. It develops a method of limiting transformations based on convergence of shifted functions, compactness …
Generated abstract This paper studies illumination from within of the boundary of unbounded convex bodies in Euclidean space, where a boundary point is illuminated by another if the open segment between them lies in the interior. It proves that the entire boundary of an unbounded convex body is internally illuminable …
Generated abstract The paper proves a decomposition theorem in dimension theory: an n-dimensional cube cannot be represented as a countable union of proper closed subsets whose pairwise intersections have dimension at most n minus 2. The argument extends Urysohn’s two-set result by using continua joining opposite face…
Generated abstract This paper examines the distribution of mercury in meteorites and its possible significance for interpreting elemental abundances in planetary materials. Using a chemical analytical method with sensitivity sufficient for iron and stony iron meteorites, the authors report about 100 determinations fro…
Generated abstract This paper studies lower bounds on the complexity, defined as representation length, of normal algorithms that decide or enumerate predicates on finite sets of words. It introduces a reducibility notion for normal algorithms and proves that universality with respect to this reducibility is equivalen…
Generated abstract The study determines the crystal structure of the anhydrous plate form of copper DL-alpha-alaninate, a compound unsuitable for conventional X-ray analysis because it forms very thin, brittle plates. Electron diffraction patterns from textured polycrystalline specimens and spot patterns were indexed …
Generated abstract This paper studies absolute stochastic stability for automatic control systems represented by nonlinear Volterra integral equations with random external inputs. It defines stochastic stability in terms of functionals measuring the input process and the corresponding solution, and derives frequency-d…
Generated abstract This paper presents a colorimetric analysis of twilight sky aureole spectra observed near the horizon from the Soyuz-5 spacecraft under conditions of continuous cloud cover and a solar depression angle near zero. Using measured monochromatic brightness and standard colorimetric functions, the author…
Generated abstract The paper introduces the polyhedron defined by positive quadratic forms with fixed arithmetic minimum and develops its basic properties in the coefficient space of quadratic forms. It shows that this polyhedron is locally finite, invariant under integral unimodular transformations, has vertices corr…
Generated abstract The paper studies local questions in Banach analytic spaces where closed subspaces need not be complemented, a difficulty that obstructs direct extension of finite-dimensional analytic arguments. It introduces a completeness condition and proves existence and factorization results for finite-dimensi…
Generated abstract This paper reports an experimental observation of low-frequency ultrasonic modulation in the radiation intensity of solid-state traveling-medium lasers, in addition to previously noted high-frequency kinematic modulation. Oscillograms from ruby and neodymium-glass traveling-medium lasers show intens…
Generated abstract This paper analyzes the radial stability of an infinite cylindrical incompressible conductor placed eccentrically inside a cylindrical surface carrying an azimuthal traveling-wave current. Using the quasi-stationary approximation, the Leontovich boundary condition, and Bessel-function expansions, it…
Generated abstract This paper investigates antiferromagnetic resonance absorption in copper chloride dihydrate in an inclined magnetic field at low microwave frequencies between 0.65 and 5.2 GHz. Measurements of the resonance field as a function of the angle between the easy axis and the external field show frequency-…
