常曲率空间中有限点集的两类几何不等式

应用距离几何的理论与方法,研究了n维常曲率空间中有限点集的一些几何度量之间关系,建立了常曲率空间中有限点集的两类几何不等式,推广了已有的结果.     

拓扑度计算与应用

本文运用锥理论计算一类全连续场的拓扑度,极大地减弱了非线性算子下方 有界的条件, 因而本质上改进和推广了现有结果. 最后,把抽象结果应用于研究超线 性Hammerstein积分方程非平凡解的存在性.     

Existence results for second order impulsive functional differential inclusions

In this paper, the existence of solution on a compact interval to second order impulsive functional differential inclusions is investigated. Several new results are obtained by using suitable fixed point theorem.     

Contractive type non-self mappings on metric spaces of hyperbolic type

Let (X,d) be a metric space of hyperbolic type and K a nonempty closed subset of X. In this paper we study a class of mappings from K into X (not necessarily self-mappings on K), which are defined by the contractive condition (2.1) below, and a class of pairs of mappings from K into X which satisfy the condition (2.28) below. We present fixed point and common fixed point theorems which are generalizations of the corresponding fixed point theorems of ?iri? [L.B. ?iri?, Quasi-contraction non-self mappings on Banach spaces, Bull. Acad. Serbe Sci. Arts 23 (1998) 25-31; L.B. ?iri?, J.S. Ume, M.S. Khan, H.K.T. Pathak, On some non-self mappings, Math. Nachr. 251 (2003) 28-33], Rhoades [B.E. Rhoades, A fixed point theorem for some non-self mappings, Math. Japon. 23 (1978) 457-459] and many other authors. Some examples are presented to show that our results are genuine generalizations of known results from this area.     

Multiple solutions for fourth-order boundary value problem

In this paper, we study the existence and multiplicity of nontrivial solutions for the fourth-order two point boundary value problems. Making use of the theory of fixed point index in cone and Leray-Schauder degree, under general conditions on nonlinearity, we prove that there exist at least six different nontrivial solutions for the fourth-order two point boundary value problems. Furthermore, if the nonlinearity is odd, we obtain that there exist at least eight different nontrivial solutions.     

Time periodic solution of the viscous Camassa-Holm equation

This paper discusses the viscous Camassa-Holm equation with a periodic boundary condition. The existence and uniqueness of a time periodic solution are investigated by using the Galerkin method and Leray-Schauder fixed point theorem.     

A one-dimensional Schrödinger operator with point interactions on Sobolev spaces

A one-dimensional Schrödinger operator with point interactions on Sobolev spaces is studied on the basis of the extension theory of nondensely defined operators.     

Closed relativistic strings in geometrically nontrivial spaces

We find exact solutions of the equations of motion for a closed relativistic string that carries a point mass and moves in the space given by the direct product of Minkowski space and a compact manifold (multidimensional torus). We investigate physical characteristics of the system states described by these solutions.Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 142, No. 1, pp. 72–82, January, 2005.     

Lax可积系统的有限变换对称群及严格解

本文用一种简单直接的方法研究了非线性物理系统Davey-Stewartson方程及（２＋１）维的Camassa-Holm方程，并给出了它们的有限变换对称群及对称。     

Stress-based upper-bound method and convex optimization: case of the Gurson materialMéthode cinématique par les contraintes et optimisation convexe : cas du matériau de Gurson

A nonlinear interior point method associated with the kinematic theorem of limit analysis is proposed. Associating these two tools enables one to determine an upper bound of the limit loading of a Gurson material structure from the knowledge of the sole yield criterion. We present the main features of the interior point algorithm and an original method providing a rigorous kinematic bound from a stress formulation of the problem. This method is tested by solving in plane strain the problem of a Gurson infinite bar compressed between rough rigid plates. To cite this article: F. Pastor et al., C. R. Mecanique 334 (2006).