一类强退化拟线性抛物方程的弱解

In this paper, we show the existence of the renormalized solutions and the entropy solutions of a class of strongly degenerate quasilinear parabolic equations.     

一类强退化抛物方程弱解的惟一性

研究了如下形式的强退化抛物方程(C)(u)/(t)=(2A(u,x,t))/(x2)+(B(u,x,t))/(x),基于Holm gren方法,证明了弱解的惟一性.     

Stability of Solutions for a Class of Quasilinear Degenerate Parabolic Equations

ＳｔａｂｉｌｉｔｙｏｆＳｏｌｕｔｉｏｎｓｆｏｒａＣｌａｓｓｏｆＱｕａｓｉｌｉｎｅａｒＤｅｇｅｎｅｒａｔｅＰａｒａｂｏｌｉｃＥｑｕａｔｉｏｎｓ￥ＺｈａｏＪｕｎｎｉｎｇ（赵俊宁）（ＩｎｓｔｉｔｕｔｅｏｆＭａｔｈｅｍａｔｉｃｓ，ＪｉｌｉｎＵｎｉｖｅｒｓｉｔ...     

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．     

EXISTENCE AND UNIQUENESS OFWEAK SOLUTIONS OF UNIFORMLY DEGENERATE QUASILINEAR PARABOLIC EQUATIONS

In this paper we deal with the quasilinear parabolic equation u/t=/x_i[a_(ij)(x, t, u))u/x_j]+b_i(x, t, u)u/x_i+c(x, t, u) which is uniformly degenerate at u=O. Under some assumptions we prove existence anduniqueness of nonnegative weak solutions to the Cauchy problem and the first boundary valueproblem for this equation. Furthermore, the weak solutions are globally Holder continuous.     

Strong and Weak Property of Travelling Wave Front Solutions for a Class of Degenerate Parabolic Equations

§ 1.Ｉｎｔｒｏｄｕｃｔｉｏｎ　Ｉｎｔｈｉｓｐａｐｅｒｗｅｓｔｕｄｙｔｈｅｓｔｒｏｎｇａｎｄｗｅａｋｐｒｏｐｅｒｔｙｏｆｔｒａｖｅｌｌｉｎｇｗａｖｅｆｒｏｎｔｓｏｌｕｔｉｏｎｓ (ＴＷＦＳ)ｆｏｒｔｈｅｆｏｌｌｏｗｉｎｇｄｅｇｅｎｅｒａｔｅｐａｒａｂｏｌｉｃｅｑｕａｔｉｏｎ : ψ(ｕ) ｔ = 2 ｕ ｘ2 +ｆ(ｕ) . ( 1 .1 )　Ｗｅｌｏｏｋｆｏｒｓｏｌｕｔｉｏｎｓｏｆ( 1 .1 )ｏｆｔｈｅｆｏｒｍｕ(ｘ,ｔ) =ｑ(ｘ -ｃｔ) (ｃｉｓｔｈｅｗａｖｅｓｐｅｅｄ) ,ｗｈｅｒｅｑ( ξ) ,ξ=ｘ -ｃｔ,ａｓａｆｕｎｃｔｉｏｎｏｆａｓ…     

一类无穷阶退化抛物方程解的存在性

设X=(X_1,...,X_m)是一组无穷阶退化向量场,Δ_X=Σ_(j=1)~m X_j~*X_j,其中X_j~*是X_j的形式自伴算子.运用不动点理论得到抛物方程u_t=Δ_Xu+u log|u|解的存在性.     

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].     

Everywhere Regularity of Solutions to a Class of Strongly Coupled Degenerate Parabolic Systems

A class of strongly coupled degenerate parabolic system is considered. Sufficient conditions will be given to show that bounded weak solutions are Hölder continuous everywhere. The general theory will be applied to a generalized porous media type Shigesada-Kawasaki-Teramoto model in population dynamics.     

Uniqueness of Piecewise Smooth Weak Solutions of Multidimensional Degenerate Parabolic Equations

We study the degenerate parabolic equationu_t + ∇ · f = ∇ · (Q∇u) + g, where (x, t) ∈ ^N × ⁺, the fluxf, the viscosity coefficientQ, and the source termgdepend on (x, t, u) andQis nonnegative definite. Due to the possible degeneracy, weak solutions are considered. In general, these solutions are not uniquely determined by the initial data and, therefore, additional conditions must be imposed in order to guarantee uniqueness. We consider here the subclass of piecewise smooth weak solutions, i.e., continuous solutions which areC²-smooth everywhere apart from a closed nowhere dense collection of smooth manifolds. We show that the solution operator isL¹-stable in this subclass and, consequently, that piecewise smooth weak solutions are uniquely determined by the initial data.     

一类双重退化抛物方程局部解的存在性

This paper deals with a class of doubly degenerate parabolic equations, including as particular cases the porous medium equation and the degenerate p- Laplace equation(p＞2) u_t-div(b(x,t,u)|▽u|~(p-2)▽u)=f(x,u,t). The initial-boundary value problem in a bounded domain of R~N is considered under mixed boundary conditions.The existence of local-in-time weak solutions is obtained.     

一类拟线性次椭圆方程弱解的局部唯一性

In this note,we obtain some a-priori estimates for gradient of weak solutions to a class of subelliptic quasilinear equations constructed by Ho¨rmander’s vector fields,and then prove local uniqueness of weak solutions.A key ingredient is the estimated about kernel on metirc ＂annulus＂.     

关于一类拟线性抛物方程Blow-up的注记

本文指出了文[1]所给条件的自身矛盾性以及运用凸性方法处理拟线性抛物型方程Blow-up性质的缺陷,同时提出了处理这类问题的较恰当的方法.     

Uniqueness of Generalized Solutions for a Quasilinear Degenerate Parabolic System

In this paper we study the uniqueness of generalized solutions for a class of quasilinear degenerate parabolic systems arising from dynamics of biological groups. The results obtained give an answer to a problem posed by A.S. Kalashnikov [1].     

On the Solvability of Double Degenerate Quasilinear Parabolic Equations

We deal with the existence of solutions for double degenerate quasilinear parabolic equations which can degenerate, on a part of the boundary, on a segment in the interior of the domain and in time. This revised version was published online in June 2006 with corrections to the Cover Date.     

Homogenization for Degenerate Quasilinear Parabolic Equations of Second Order

In this paper we study the homogenization of degenerate quasilinear parabolic equations: where a(t, y, a, λ) is periodic in (t, y).     

On Doubly Degenerate Quasilinear Parabolic Equations of Higher Order

We deal with the existence of periodic solutions for doubly degenerate quasilinear parabolic equations of higher order, which can degenerate, on a part of the boundary, on a segment in the interior of the domain and in time.     

Localized Blow-Up Regimes for Quasilinear Doubly Degenerate Parabolic Equations

Mathematical Notes - Singular blow-up regimes are studied for a wide class of second-order quasilinear parabolic equations. Energy methods are used to obtain exact (in a certain sense) estimates of...