具线性增长系数的拟线性挠射问题弱解的正则性

讨论了具特殊主部和线性增长系数的n维拟线性抛物挠射问题,利用估计和平均函数方法,证明了弱解在内边界附近的一些正则性质.把这些正则性结果从线性问题推广到这种拟线性问题.     

一类拟线性椭圆方程边值问题弱解的研究

本应用上、下解方法和Learay-Schauder不动点定理，证明了一类拟线性椭圆方程边值问题弱解的存在性,并且给出了一个应用实例。     

一类拟线性椭圆型方程很弱解的局部正则性

本文考虑一类拟线性椭圆型方程的很弱解．使用Hodge分解等工具，得到了其局部正则性，推广了[1]之结果。     

具间断系数拟线性退化椭圆方程在可控增长下的正则性

对于具有VMO间断系数的散度型拟线性退化椭圆型方程,考虑了低阶项微分项在可控制增长条件下的弱解梯度的Morrey空间L^p,λ局部正则性,从而在已知数据正则性提高的条件下得到弱解具有优化Hlder指数的Hlder连续性结果。     

拟线性抛物方程的弱解

该文给出了拟线性退化抛物方程pa_t{u}+pa_x{f(u)}=pa_xx{A(u(x,t))}∈R^2_+×(0,+∞) ,u(x,0)=u_0(x),x∈R 一种弱解的新定义, 利用Div Curl引理证明了解的存在性．     

间断系数的二阶椭圆型方程解的正则性

该文研究的问题源自于生物学与物理学中具有间断介电系数的静电场。作者以拟微分算子为主要工具讨论具间断系数的半线性二阶椭圆型方程解的存在性和正则性 。     

一类退缩的椭圆型方程弱解的正则性

本文给出了一类退缩的拟线性椭圆型方程－Ｄｉｖ「↓ｕ｜＾ｐ－２↓ｕ＋Ｆ（ｘ,ｕ）」＝Ｂ（ｘ,ｕ,↓ｕ）在Ｗ＾１,ｐ（Ω）中弱解的Ｃ＾１,λｌｏｃ（Ω）正则性,其中Ω为Ｒ＾Ｎ中行一区域。     

具有临界指数的半线性椭圆组弱解的正则性

本文研究具有临界指数的方程组。用ＤｅＧｉｏｒｇｅ估计方法，获得方程组的解的有界性。     

自然增长下的具VMO系数拟线性椭圆组的部分正则性

设散度型拟线性系数算子关于自变量x一致满足VMO的结构条件,对于低阶项满足自然增长条件的拟线性椭圆方程组,建立了其弱解具有确切Holder指数的部分正则性.     

Global Regularity of Weak Solutions to Quasilinear Elliptic and Parabolic Equations with Controlled Growth

We establish global regularity for weak solutions to quasilinear divergence form elliptic and parabolic equations over Lipschitz domains with controlled growth conditions on low order terms. The leading coefficients belong to the class of BMO functions with small mean oscillations with respect to x.     

非线性椭圆型偏微分方程弱解的存在性

在W1,p(x)空间框架下研究了具有p(x)增长条件的椭圆型偏微分方程:-d iva(x,u,D u) g(x,u,u)=f,得到了在W10,p(x)空间中弱解的存在性,推广了Boccardo等关于在Sobo lev空间中弱解的相应结论.     

Continuity of Weak Solutions for Quasilinear Parabolic Equations with Strong Degeneracy

The aim of this paper is to study the continuity of weak solutions for quasilinear degenerate parabolic equations of the form U_t-Δφ(u)=O, whereφ■C~1(R~1)is a strictly monotone increasing function.Clearly,the above equation has strong degeneracy,i.e.,the set of zero points ofφ′(·)is permitted to have zero measure. This is an answer to an open problem in[13,p.288].     

Positive Solutions of a Class of Quasilinear Elliptic Equations in Two-dimensional Exterior Domains

Sufficient conditions for the existence of positive solutions to a class of quasilinear elliptic equations in two-dimensional exterior domains are given.     

Regularity of Weak Solutions of Nonlinear Equations with Discontinuous Coefficients

In this paper, we prove that the weak solutions u∈Wloc^1, p （Ω） （1 〈p〈∞） of the following equation with vanishing mean oscillation coefficients A（x）： -div[（A（x）△↓u·△↓u）p-2/2 A（x）△↓u＋│F（x）│^p-2 F（x）]=B（x, u, △↓u）, belong to Wloc^1, q （Ω）（A↓q∈（p, ∞）, provided F ∈ Lloc^q（Ω） and B（x, u, h） satisfies proper growth conditions where Ω ∪→R^N（N≥2） is a bounded open set, A（x）=（A^ij（x）） N×N is a symmetric matrix function.     

A Posteriori Error Estimators for Elliptic Equations with Discontinuous Coefficients

We consider linear elliptic equations with discontinuous coefficients in two and three space dimensions with varying boundary conditions. The problem is discretized with linear finite elements. An adaptive procedure based on a posteriori error estimators for the treatment of singularities is proposed. Within the class of quasi-monotonically distributed coefficients we derive a posteriori error estimators with bounds that are independent of the variation of the coefficients. In numerical test cases we confirm the robustness of the error estimators and observe that on adaptively refined meshes the reduction of the error is optimal with respect to the number of unknowns.     

Very Weak Solutions of p-Laplacian Type Equations with VMO Coefficients

In this note we obtain a new a priori estimate for the very weak solutions of p-Laplacian type equations with VMO coefficients when p is close to 2, and then prove that the very weak solutions of such equations are the usual weak solutions. Our approath is based on the Hodge decomposition and the L^p-estimate for the corresponding linear equations. And this also provides a simpler proof for the results in [1].     

关于椭圆方程弱解的Fatou逆定理的证明

证明非光滑区域上的散度型二阶椭圆方程αi(aij(X)αju(X))=0的弱解的Fatou逆定理及Dirichlet问题的惟一性．     

拟线性椭圆型方程带有混合奇异项的正整体解

在本文中,研究了方程div(｜u｜p-2u) f(x,u)=0,x∈RN,N≥3的正整体解,其中f(x,u)在u=0未假定是正则的,且f(x,u)可以同时包含超线性,亚线性项和奇异项.