抛物型边界热源方程的爆破解及其上下界

讨论了一类典型的半线性抛物型方程,其在物理上对应具有边界热源的热传导问题,证明了非平凡解发生爆破的充分条件,并讨论了爆破速率之上界与下界.     

On Stabilization of the Solution of the Cauchy Problem for a Parabolic Equation with a Lower Order Coefficient and a Growing Initial Function

The paper deals with the study of sufficient conditions on the coefficients of a second-order partial differential equation, ensuring the stabilization to zero of the solution of the Cauchy problem uniformly in x on any compact set K ^N for any continuous initial function u ₀(x), growing at infinity not faster than some power of |x| ^m , m > 0.     

离散时间代数Riccati方程的解矩阵的下界与上界

本文讨论离散时间代数Ｒｉｃｃａｔｉ方程ＡＴＸＡ－Ｘ－（ＡＴＸＢ＋Ｌ）（Ｒ＋ＢＴＸＢ）＾－１（ＬＴ＋ＢＴＸＡ）＋Ｑ＝０的唯一对称正定解的上界和下界。     

离散代数Riccati方程解的上下界

给出离散代数Ｒｉｃｃａｔｉ方程解的迹的上界和下界计算公式,较现有结果相比,该结果具有较高的估计精度,数值算例表明该方法的有效性。     

The Cauchy Problem for the p-Laplacian Equation with a Nonlinear Source

In this paper we study the existence and uniqueness of positive solutions for the p-Laplaeian equation with nonlinear source eu/et=div(|Du|^p-2Du) u^-q,p＞2,0＜q＜∞ in the class of functions with some prescribed growth rate as|x|→∞. We also give a deseription of the large time behaviour and show that it is determined by thep ecompetition between the diffusion and the souree.     

一类拟线性退化抛物方程的Cauchy问题

对方程α（xx）u＋uαyu-αtu=f（·,u）,（x,y,t）∈R^2×（0,T）的Cauchy问题,给出了一个整体BV-弱解的定义,证明了该弱解的连续性.     

拟线性抛物型方程奇异摄动问题的数值解法

本文讨论拟线性抛物型方程奇异摄动问题的差分解法,在非均匀网格上建立了线性三层差分格式,并证明了在离散的L₂范数意义下格式的一致收敛性,最后给出了一些数值例子.     

Two-Parameter Asymptotics in a Bisingular Cauchy Problem for a Parabolic Equation

The Cauchy problem for a quasilinear parabolic equation with a small parameter ε at the highest derivative is considered. The initial function, which has the form of a smoothed step, depends on a “stretched” variable x/ρ, where ρ is another small parameter. This problem statement is of interest for applications as a model of propagation of nonlinear waves in physical systems in the presence of small dissipation. In the case corresponding to a compression wave, asymptotic solutions of the problem are constructed in the parameters ε and ρ independently tending to zero. It is assumed that ε/ρ → 0. Far from the line of discontinuity of the limit solution, asymptotic solutions are constructed in the form of series in powers of ε and ρ. In a small domain of linear approximation, an asymptotic solution is constructed in the form of a series in powers of the ratio ρ/ε. The coefficients of the inner expansion are determined from a recursive chain of initial value problems. The asymptotics of these coefficients at infinity is studied. The time of reconstruction of the scale of the internal space variable is determined.     

具有弱阻尼项的广义IMBq方程初值问题解的整体存在性

证明具有弱阻尼项的广义IMBq方程乱u_(tt)-u_(xx)-u_(xxtt)+v_0u_t=f(u)_(xx),x∈R,t0的初值问题在C~2([0,∞);H~s(R))(s2是一实数)中存在惟一整体广义解和在C~2([0,∞);H~s(R))(s2/7)中存在惟一整体古典解,并给出上述初值问题解爆破的充分条件.     

带吸收项的非线性双重退缩抛物方程的Cauchy问题

讨论带吸收项的非线性双重退缩抛物方程ut=div(│↓△u^m│^p-2↓△u^m)-u^q u(x,0)=u0(x)的Cauchy问题。     

拟线性退化抛物方程Cauchy问题的解

对来自金融数学领域的方程_xxu+u_yu-_tu=c（x,y,t,u）,（x,y,t）∈Q_T=R²×[0,T)的Cauchy问题,给出了一种新的熵解的定义,得到了其适定性结果.可以证明所得到的解还是强解,即方程中所出现的各阶偏导数几乎处处连续.最后讨论了解的爆破性质以及与解的间断点相关的几何性质.     

Asymptotic Solution of the Cauchy Problem for a First-Order Differential Equation with a Small Parameter in a Banach Space

Mathematical Notes - The Cauchy problem for a first-order differential equation with a small parameter multiplying the derivative in a Banach space is considered. The right-hand side of the...     

一个四阶抛物方程整体弱解的正则性

本文研究一个四阶抛物方程的非负大初值混合Dirichlet-Neumann边值问题.使用半离散化解的精细熵估计与插值技巧,得到了正则性更好的整体弱解.