Translated papers from the Chinese Preprint site, Chinaxiv
Showing 50 of 15526 papers
Generated abstract This paper studies harmonic vector functions in the upper half-space satisfying generalized Cauchy-Riemann conditions, with emphasis on multidimensional analogues of classical results on conjugate harmonic functions. It defines Hardy-type classes H^p and S^p, gives a Fourier-transform characterizati…
Generated abstract The paper studies traces of functions in anisotropic Sobolev spaces on smooth hypersurfaces under a condition relating the minimum and maximum smoothness indices. Building on a general characterization of trace spaces by an integral equation with kernel determined by the surface and the Sobolev norm…
Generated abstract The paper studies the decomposition of the tensor product of two irreducible maximally degenerate unitary representations of the group of complex matrices of order n with determinant 1, for n at least 3. Using a modification of the horosphere transform method of Gelfand and Graev, the tensor product…
Generated abstract This note applies Strassen’s fast matrix multiplication to the computation of the transitive closure of a directed graph. It observes that Boolean matrix multiplication can be carried out by ordinary multiplication of zero one matrices followed by thresholding, giving a bound of order n to the log b…
Generated abstract This paper studies a Cauchy problem for second order hyperbolic equations containing a small positive parameter, with initial data that produce an initial jump in the singular limit. It constructs a matched asymptotic expansion in powers of the parameter, combining regular terms satisfying reduced f…
Generated abstract This paper classifies Harish-Chandra modules for the group SL(2,C), understood as representations whose dense subspace decomposes algebraically with finite multiplicities under a maximal compact subgroup. It constructs elementary modules from associated homogeneous functions, describes their composi…
Generated abstract Joint Franco-Soviet rocket experiments on Hayes Island in 1967 and 1968 measured temperature, winds, and diffusion in the polar upper atmosphere using artificial luminous sodium and aluminum oxide clouds released at about 120 to 174 km. Temperatures were derived from Doppler broadening of sodium res…
Generated abstract This paper studies an inverse spectral problem for the Hill equation with a real periodic potential, focusing on what data beyond the discriminant are sufficient to determine the potential uniquely. It introduces a matrix built from the fundamental solutions over one period and proves that equality …
Generated abstract The paper addresses the difficulty of interpreting gas-dynamic interferograms in monochromatic light when fringe breaks, crowding, or discontinuities prevent direct fringe tracking, a problem often resolved by also recording achromatic fringes. It proposes a method for determining the integer optica…
Generated abstract This paper extends S. I. Vavilov’s theory of concentration depolarization of fluorescence by incorporating temperature and viscosity as variables affecting resonance migration of excitation energy in viscous solutions. Treating fluorescent molecules as Brownian particles, the authors derive collisio…
Generated abstract This paper develops a calculation method for the stable roughness that forms after running-in during sliding elastic contact. Using the molecular-mechanical theory of friction together with a fatigue interpretation of wear, the authors argue that the stable surface state corresponds to the roughness…
Generated abstract This note studies estimation of unknown finite-dimensional regression functions in the mean of a random function with known correlation kernel. Using reproducing-kernel Hilbert spaces and extended kernels, it characterizes canonical isometries associated with the random function and derives uniforml…
Generated abstract This paper examines whether the temperatures of planetary exospheres and the solar corona are constrained by the gravitational potentials of their parent bodies. By comparing the Earth’s upper exosphere and the upper solar corona, it notes that the ratio of hydrogen particle thermal energy to gravit…
Generated abstract This paper studies the state complexity of operations on regular sets of words represented by finite automata, taking the number of states in a minimal representing automaton as the complexity measure. It gives binary alphabet examples showing that known upper bounds for union, product, and iteratio…
Generated abstract The paper studies continuous positive functionals that are linear with respect to Minkowski addition and nonnegative scalar multiplication on convex compact sets, equivalently on convex surfaces via support functions. It identifies these functionals with elements of the dual cone of sublinear functi…
Generated abstract The paper develops a method for constructing separatrix surfaces and stability regions in the phase spaces of nonlinear systems of the form consisting of a linear part plus a scalar nonlinearity. By transforming the system to diagonal coordinates and introducing two-dimensional revealing sections in…
Generated abstract This paper investigates how thermal vibrations of lattice atoms affect the angular and energy distributions of low energy ions scattered by single crystals. Rubidium ions with energies below 5000 eV were directed at molybdenum single crystal surfaces at varied incidence, emergence, scattering, azimu…
Generated abstract The paper studies two-dimensional integral equations on a disk whose kernels are homogeneous of order minus two and satisfy a weighted summability condition. Using complex notation, polar coordinates, and Fourier expansion in the angular variable, the equation is reduced to a diagonal system of one-…
Generated abstract The paper justifies Bogolyubov’s averaging method for abstract parabolic equations in a Banach space, considering evolution equations with a rapidly varying nonlinear term and an unbounded linear operator generating an analytic semigroup. Under assumptions on fractional power spaces, compactness, di…
Generated abstract This note studies when realizability of propositional formulas coincides with derivability in Heyting’s intuitionistic propositional calculus, focusing on formulas with limited nesting of implication. It defines a hierarchy measuring the occurrence of implication and proves that every realizable for…
Generated abstract This paper develops a linearization principle for the stability of periodic self-oscillations in infinite-dimensional dynamical systems, formulated as nonlinear partial semigroups on a Banach space. It proves an analogue of the Andronov-Witt theorem: a smooth cycle is asymptotically stable with asym…
Generated abstract This paper studies regularization of solvable but unstable extremal problems over closed convex subsets of real Banach spaces, for quasiconvex lower semicontinuous functionals. The proposed method replaces the original minimization by the search for the least norm element in approximate level sets, …
Generated abstract The paper constructs and estimates the fundamental matrix for a second order elliptic system in a three-dimensional domain with a complex spectral parameter. Under smoothness assumptions on the matrix coefficients and a negativity condition on the real parts of the roots of the characteristic equati…
Generated abstract This study examines the morphology of polymorphic transformations in potassium nitrate, with emphasis on the growth of the high-temperature beta phase from single-crystalline alpha-phase specimens. Using purified, well-faceted crystals and microscopic observation on a thermostated heating stage, the…
Generated abstract This study examines whether helium concentrations in groundwater can indicate deep tectonic faults along a deep seismic sounding profile in the Trans-Urals. Water samples, mainly from pumped wells 80 to 100 m deep, were degassed by vacuum extraction and analyzed for helium, then compared with seismi…
Generated abstract This paper studies steepest descent type methods for solving nonlinear operator equations in real Hilbert spaces under assumptions weaker than the usual uniform positivity condition on the derivative. It analyzes continuous trajectories defined by differential equations involving the residual and it…
Generated abstract This paper studies differential games of approach for linear controlled systems with convex control constraints, constraints on selected phase coordinates, and terminal payoffs measuring distance to a target set. It formulates a programmed approach problem and an adjoint optimization problem in dist…
Generated abstract This paper examines how the deformation force associated with motion of the Earth’s rotational pole may affect atmospheric circulation, especially the positions of the Icelandic low and Azores high. The authors derive the vertical and horizontal components of the force, argue that the vertical compo…
Generated abstract This paper investigates camouflet cavity formation produced by spherical explosive charges in liquids and elastoplastic media, including water, zinc chloride solution, wet clay, aluminum, cement and sand mortar, and rock salt. The authors combine pulsed radiographic measurements of cavity expansion …
Generated abstract The paper studies uniqueness for the Cauchy problem for linear evolution systems with variable coefficients, including systems of arbitrary type solved with respect to time and systems whose spatial part is elliptic or parabolic in the sense of Petrovsky. It develops a weighted L1 estimate in a thin…
Generated abstract The paper studies neutrino fields in general relativity governed by the Einstein-Dirac system, with attention to solutions invariant under three-dimensional motion groups acting on two-dimensional nonisotropic transitivity surfaces. By representing spinors through associated real tensor fields, it d…
Generated abstract This paper develops a theoretical treatment of nuclear magnetic relaxation in molecular crystals arising from intramolecular dipole dipole interactions when molecules undergo hindered reorientation about a fixed axis. Using the distribution of molecular orientations for random rotational jumps in a …
Generated abstract This paper studies periodic oscillations of systems that are close to essentially nonlinear differential systems with a small parameter, focusing on the special case in which the first solvability conditions for the principal amplitudes are identically satisfied for part of the arbitrary constants. …
Generated abstract This paper develops a quantitative physical model for the geyser process, treating eruptions as explosive releases of superheating energy accumulated in an underground water chamber under hydrostatic pressure. The authors analyze the induction interval between eruptions using a simplified system in …
Generated abstract This paper studies infinitely divisible probability laws whose alpha-components are all infinitely divisible, a subclass arising in the theory of decompositions of probability laws. It gives a sufficient condition, distinct from earlier criteria of Linnik, for a law with a compound Poisson type Lévy…
Generated abstract The note classifies nontrivial trisymmetric homogeneous Riemannian spaces with simple compact Lie groups of motions. It reformulates trisymmetry in terms of invoproducts and corresponding involutive sums of Lie algebras, proves auxiliary restrictions on the mirrors and isotropy subgroups, and reduce…
Generated abstract This paper studies an elliptic boundary value problem with two free boundaries, formulated as finding a Sobolev function constrained between two obstacles and satisfying complementary sign conditions for an elliptic operator. The analysis connects this problem with a two-sided optimal stopping game …
Generated abstract This paper studies estimates for the S-numbers of functions of positive linear operators in Banach spaces, including fractional powers, logarithms, iterated logarithms, and analytic semigroups. Using integral representations of fractional powers and logarithms together with standard inequalities for…
Generated abstract The paper proposes a general method for solving uniquely posed problems of mathematical physics by omitting different conditions, representing the resulting families of partial solutions as functional sets, and finding the original solution as their common element. It formulates both exact and far-z…
Generated abstract This paper studies whether nonlinear curvature terms in the gravitational Lagrangian can remove cosmological singularities while preserving the usual Friedmann behavior at low curvature. Using field equations derived from an action of the form \(R + l^{-2}(l^2 R)^{4/3}\), the author constructs exact…
Generated abstract This crystallographic note proves a theorem on recovering an acentric basic system of points in the Fedorov group P1 from its vector system when the vector system contains a peak of multiplicity n arising from n equal point-pair vectors, under restrictions excluding higher accidental coincidences. U…
Generated abstract The paper studies a second order Schrödinger type differential operator in a Hilbert space of Bochner integrable functions, with an operator valued potential depending on the real variable. Under assumptions on sectorial boundedness, Hölder continuity, growth of the operator family, and compactness …
Generated abstract This paper reports ultrasonic measurements of longitudinal and transverse sound velocities in polycrystalline cesium chloride and sodium chloride under quasi-hydrostatic pressures up to about 100 kbar. Using a high-pressure chamber, corrected specimen-length measurements, and transit-time data refer…
Generated abstract This note studies an averaging procedure for nonlinear integro-differential equations with a small parameter, in which the memory term is replaced by an integral over an infinite interval and the resulting vector field is time averaged. Under continuity, Lipschitz, boundedness, and growth assumption…
Generated abstract This paper formulates the Einstein equations for spatially homogeneous gravitational fields in a comoving reference system, motivated by cosmological applications where the physical behavior of matter is most naturally described along the medium flow. Starting from metrics admitting a three-dimensio…
Generated abstract The paper gives a proof of Hayman’s regularity theorem for coefficients of univalent functions by establishing a more general sufficient condition for regular coefficient growth. For functions normalized in the unit disk, it assumes a maximal growth condition along a radius and a square summability …
Generated abstract This note studies isometric immersions of two-dimensional Riemannian metrics into Euclidean three-space by surfaces of class C1 under an added condition of regularity with respect to affine transformations. It introduces affine regularity and proves structural results for immersions of metrics of bo…
Generated abstract The paper develops a refinement of uniform homology groups for metric spaces, motivated by the inability of earlier groups to distinguish manifolds whose bounding chains grow with different diameter orders. For each admissible order of growth, it defines subsets determined by cycles requiring chains…
Generated abstract The paper studies approximation of continuous and differentiable functions on the unit cube by generalized polynomials, defined as finite linear superpositions of functions of fewer variables with respect to prescribed one variable systems. It establishes existence and characterization results for b…
Generated abstract This paper examines evidence for a low-velocity seismic waveguide in the crust of the Garm region of Central Asia. Using earthquakes from two localized focal zones as plunging sources, the authors construct and interpret systems of mean travel-time curves for longitudinal and transverse waves, suppl…
