一类拟线性抛物方程组的整体解

本文通过引进熵－熵流时，证明了一类拟线性物方程组Ｃａｕｃｈｙ问题解的整体存在性定理。     

一个拟线性抛物型方程组的研究

该文研究如下柯西问题：　此方程组类似于外力依赖于速度的Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程组．研究它是为研究一般Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程组作准备。另一方面，它也可以看作一个高维双曲型方程组　加上粘性项．而（＊）是一个一般高维守恒律的模型．当ｎ＝２，ｆ（ｕ）＝０时，张同等曾经详细研究过它们的Ｒｉｅｍａｎｎ问题．     

半线性抛物型方程组解的整体存在性与爆破速率估计

研究了具有非线性热源的半线性抛物型方程组的齐次neumann问题解的爆破性质.利用上下解方法得到了解整体存在的条件与爆破条件,并利用FriedmannMcleod方法建立了爆破速率估计.     

一类半线性抛物型方程组解的爆破速率估计

考虑一类带有齐次Dirichlet边界条件且反应项分别为指数形式和幂函数形式的半线性抛物型方程组,利用比较原理得到了方程解爆破的充分条件,由数学分析原理和最大值原理得到了爆破解的爆破速率估计.     

拟线性退化抛物型方程组解的整体存在性和爆破

该文研究光滑有界区域Ω( R^N (N≥ 1) 上具有齐次Dirichlet边界条件的拟线性退化抛物型方程组 u_t-div(|▽u|^p-2 ▽u) =av^α, v_t-div(|▽v|^q-2 ▽v) =bu^β 的非负解的性质, 其中p, q>2, α, β ≥ 1, a, b> 0是常数. 该文指出上述方程组的解是否在有限时刻爆破依赖于初值、系数 a 与 b以及 αβ 和 (p-1)(q-1)之间的关系.     

具有间断非线性项的拟线性抛物型方程

本文研究具有间断非线性项的拟线性抛物型方程，利用Ｃｌａｒｋｅ广义梯度和伪单调算子理论证明了解的存在性。     

拟线性抛物型方程组的一类经济差分方法

拟线性抛物型方程组的一类经济差分方法韩臻，沈隆钧，符鸿源（北京应用物理与计算数学研究所）ＡＣＬＡＳＳＯＦＥＣＯＮＯＭＩＣＡＬＤＩＦＦＥＲＥＮＣＥＭＥＴＨＯＤＳＦＯＲＱＵＡＳＩ－ＬＩＮＥＡＲＰＡＲＡＢＯＬＩＣＳＹＳＴＥＭＳ￥ＨａｎＺｈｅｎ；ＳｈｅｎＬｏ...     

一类拟线性抛物方程解的Blow—up

本文讨论了拟线性抛物方程具有第三类非线性边界条件的解的爆破性质,证明了解在有限时刻T_0爆破。     

一类半线性抛物方程组解的存在性

有阻尼混合气体的导热过程由下列方程给出其中,λ=ρCD/K,D是扩散系数,ρ、C、K分别是密度、比热和热导率,u、v是温度和浓度,f(u)v是反应速度. 在—∞相似文献   

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.     

一类拟线性退缩抛物型方程整体解的存在性与衰减估计

本文讨论了一类拟线性抛物型方程初边值问题整体解的存在性和衰减估计.所得结果改进并推广了文献[1]的相应结果.     

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].     

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.     

A Problem with Nonlocal Boundary Conditions for a Quasilinear Parabolic Equation

The solvability of the nonlocal boundary value problem

Extremality in Solving General Quasilinear Parabolic Inclusions

The paper deals with an initial boundary-value problem for a parabolic inclusion whose multivalued term has the structure of a difference between the Clarke generalized gradient of some locally Lipschitz function verifying a unilateral growth condition and the subdifferential of a convex function, and where the elliptic part is expressed by a general quasilinear operator of the Leray-Lions type. Our results address not only the existence of solutions, but also the extremality inside an order interval determined by appropriately defined upper and lower solutions as well as the compactness of the solution set in suitable spaces.     

具有非局部源的退化半线性抛物型方程组解的爆破

本文讨论具有非局部源退化半线性抛物型方程组的初边值问题 .证明了局部解的存在唯一性并且得到当初值充分大时解在有限时刻爆破 .     

一类拟线性抛物系统解的整体存在性

采用非线性分析的方法 ,在任意带光滑边界的区域内 ,研究一类带交错扩散影响的拟线性抛物系统 ,证明了解的整体存在性 .     

On a Class of Quasilinear Parabolic Equations of Second Order with Double-degeneracy

In this paper we study the first boundary value problem for nonlinear diffusion equation \frac{∂u}{∂t} + \frac{∂}{∂x}f(u) = \frac{∂}{∂x}A(\frac{∂}{∂x}B(u)) whereA(s) = ∫¹_0a(σ)dσ, B(s) = ∫¹_0b(σ)dσ with a(s) ≥ 0, b(s) ≥ 0. We prove the existence of BV solutions under the much general structural conditions lim_{s → + ∞} A(s) = +∞, lim_{s → - ∞} A(s) = -∞ Moreover, we show the uniqueness without any structural conditions.     

Convergence of Iterative Difference Method with Nonuniform Meshes for Quasilinear Parabolic Systems

In this paper, we study the general difference schemes with nonuniform meshes for the following problem: u_t = A(x,t,u,u_x)u_{xx}, + f(x,t,u,u_x), 0 < x < l, 0 < t ≤ T \qquad (1) u(0,t) = u(l ,t) = 0, 0 < t ≤ T \qquad\qquad (2) u(x,0) = φ(x), 0 ≤ x ≤ l \qquad\qquad (3) where u, φ, and f are m-dimensional vector valued functions, u_t = \frac{∂u}{∂t}, u_x = \frac{∂u}{∂x}, u_{xx} = \frac{∂²u}{∂_x²}. In the practical computation, we usually use the method of iteration to calculate the approximate solutions for the nonlinear difference schemes. Here the estimates of the iterative sequence constructed from the iterative difference schemes for the problem (1)-(3) is proved. Moreover, when the coefficient matrix A = A(x, t, u) is independent of u_x, t he convergence of the approximate difference solution for the iterative difference schemes to the unique solution of the problem (1)-(3) is proved without imposing the assumption of heuristic character concerning the existence of the unique smooth solution for the original problem (1)-(3).