任意权函数的最佳逼近

本文对非对称的任意权函数(可以取值∞的非负不连续函数)的最佳逼近建立切比晓夫理论,包括存在性、唯一性、交错定理和其他定理,从而拓广了经典的切比晓夫理论.     

DEGENERATE BOUNDARY LAYER SOLUTIONS TO THE GENERALIZED BENJAMIN-BONAMAHONY-BURGERS EQUATION

This paper is concerned with the convergence rates of the global solutions of the generalized Benjamin-Bona-Mahony-Burgers(BBM-Burgers) equation to the corresponding degenerate boundary layer solutions in the half-space.It is shown that the convergence rate is t-(α/4) as t →∞ provided that the initial perturbation lies in H α 1 for α < α(q):= 3 +(2/q),where q is the degeneracy exponent of the flux function.Our analysis is based on the space-time weighted energy method combined with a Hardy type inequality with the best possible constant introduced in [1].     

边界层形态的另一描述

利用Lions在Sobolev空间中的边界层理论和Pohozaev恒等式的一般形式和高阶形式,给出边界层形态的另一描述.     

STABILITY OF BOUNDARY LAYER TO AN OUTFLOW PROBLEM FOR A COMPRESSIBLE NON-NEWTONIAN FLUID IN THE HALF SPACE

This paper investigates the large-time behavior of solutions to an outflow problem for a compressible non-Newtonian fluid in a half space. The main concern is to analyze the phenomena that happens when the compressible non-Newtonian fluid blows out through the boundary. Based on the existence of the stationary solution, it is proved that there exists a boundary layer(i.e., the stationary solution) to the outflow problem and the boundary layer is nonlinearly stable under small initial perturbation.     

RIEMANN BOUNDARY VALUE PROBLEM WITH RESPECT TO THE PERTURBATION OF BOUNDARY CURVE TO BE AN OPEN ARC

By dint of the stability of Cauchy-type integral with kernel density of class H＊ for an open arc, this paper discusses the stability of the solution of Riemann boundary value problem with respect to the perturbation of boundary curve to be an open arc.     

四阶方程奇摄动理论的边界层估计

椭圓边界层理论是偏微分方程奇摄动理论重要的一章。其一般理论是在Sobolev空间H~m(Ω)中,考虑椭圓算子εAu_ε Bu_ε=f(0<ε《1),A是2m阶,B是2m′阶,m>m′。相应于A的双线性形式记为a_(2m)(u,v)=(Au,v)。在闭凸集K_m H~m(Ω)中,求解u_ε。在空间H~m′(Ω)中,有极限算子Bu=f。在闭凸集K_(m′)H~_(m′)(Ω)中,求解u。当u     

Cayley-Bacharach定理在沿平面代数曲线插值问题中的应用

1 引 言 本文是讨论关于沿平面代数曲线的Lagrange插值问题,该问题与在二维实平面R~2上的二元Lagrange插值有关.设n为非负整数并且e_n=1/2(n+1)(n_2).P_n代表所有全     

IRROTATIONAL APPROXIMATION TO STEADY SUPERSONIC FLOW IN TWO SPACE VARIABLES

On the assumption that the total variation of the initial data is sufficiently small, we can use the stability results of Dafermos to get the L2 estimate of the difference between the solutions to the isentropic steady Euler system and the potential flow equations with the same initial data.     

ON THE ERROR ESTIMATE OF LINEAR FINITE ELEMENT APPROXIMATION TO THE ELASTIC CONTACT PROBLEM WITH CURVED CONTACT BOUNDARY

1. PreliminaryThe error estimate of linear finite element approximation to the elastic contact problem with curved contact boundary was considered in [2], in which the authors obtainedthe error bound of O(hl) with a much complex proof, requirement of three times continuously differentiable for contact boundary and extra regularities of triangulation (c.f. [2, Theorem 3.3, p.149]). In this paper, we obtained the error bound of O(hi) withonly requirement of two times continuously differentiable…     

BOUNDARY LAYER ESTIMATION OF THE QUASILINEAR STOKES EQUATIONS

1IntroductionConsidertheequationwhereaisaconstantin(0,1).ThesolutionisclearlyWenowomittheviscositytermandaboundaryconditionof(1.1)asfollows:Thesolutionof(1.2)isForesmallandx>E,thetwosolutionsareclosetogether.Theregionwheretheyaredrasticallydifferentisconfinedtotheinterval[0,E],whichisthesthcalledboundarylayer.Notesthatase~0,theboundarylayershrinkstozero,hiltthemaximumdifferencebetweenIReceivedMar.9,1995;revisedSep.18,1996.ThisworkissupportedbyFoundationoflhstituteofMathematics,Acadedasin…