一类强交错扩散的捕食模型弱解的整体存在性

考虑一类带有强交错扩散项的捕食模型解的整体存在性.借助于有限差分方法和熵不等式的相关性质及结论,证明了在高维空间上,该问题有整体存在的弱解.此外,还说明了所得的这个弱解是非负解.     

趋化NS系统弱解的全局存在性（英文）

本文主要研究趋化NS系统在2维的有界光滑领域Ω?R~2中.本文利用Galerkin方法证明了不可压缩的NS系统弱解的存在性.其次,利用一系列检验程序,证明了带有初边值条件的趋化NS系统弱解的局部存在性,进一步得到该系统弱解的全局存在性.     

一种新的固固相变模型的弱解的存在性（英文）

本文研究了一个新的基于构型力的序参数不守恒的相变模型.这个模型由两个线性方程和一个非线性的抛物方程组成.给出了其初边值问题的弱解的一种定义,并在一维情形下证明了弱解的存在性.     

一类加权Kirchhoff方程非线性Liouville定理

本文侧重研究一类加权Kirchhoff方程弱解及稳定解的非线性Liouville型定理.利用适当构造试验函数技巧,当非线性函数满足适当条件时,我们在加权函数空间中证明了该方程弱解的非存在性.同时,当非线性函数为指数型且加权函数满足适当条件时,建立了方程稳定解的非存在性结论.     

基于变分法的回火分数阶脉冲微分系统分析

该文在恰当的容许函数空间中讨论了具有瞬时和非瞬时脉冲的回火分数阶微分方程耦合系统的Dirichlet边值问题.利用变分法得到弱解存在性和唯一性的充分条件,进一步证明了每个弱解都是古典解.最后给出一个实例证明了理论结果的可行性.     

一类非牛顿系统在三维无界区域中弱解的存在性(英文)

本文考虑一类非牛顿系统在三维无界区域中解的情况 ,证明了当f∈L2 ( 0 ,T ;H)时弱解的存在性 ;当f∈L∞( 0 ,∞ ;H)时弱解的全局存在性 .     

可压Navier-Stokes方程真空状态的动力学行为

本文主要考虑了一维可压Navier-Stokes方程真空状态的动力学行为.对于任意的熵弱解,如果初始状态不存在真空,我们证明了密度函数关于时间和空间变量是连续的且对于任意时间它是处处为正的.同时,我们还得到了含有间断连接的真空状态的整体熵弱解的存在性,结果显示其真空区域以代数速率被压缩,并在有限时间内消失.     

一类双调和方程的多解性

本文研究了非线性项在无穷远处次线性增长的一类双调和方程解的存在性和多解性.应用抽象临界点定理,证明了此类双调和方程至少有三个弱解存在.     

二维Stokes近似系统弱解的全局存在性

本文主要考虑了二维可压流体的Stokes近似系统,我们运用类似于Eduard Feireisl的方法证明了Stokes近似系统在,γ=1与γ>1时弱解的全局存在性.     

带雪崩项的半导体方程的瞬态解

研究带雪崩项的半导体方程的混合初边值问题．采用逼近过程和先验估计,在一定条件下,证明了该问题整体弱解的存在性或局部弱解的存在性．     

ANALYSIS OF THE PERIODIC BAUTIN CHEMICAL OSCILLATION SYSTEM

1IntroductionIfl1939,N.N.Bautill[1,2]studiedasystemofcouplednolllilleardifferelltialequations'whichhasseverall'eaturcsofinterestforthestudyofchemicaloscillations.M*-L.Sinoes[3]showedthatfurthertheBautinsystemisaveryadequatemodelforchemicaloscillations,the…     

拟线性对称双曲型方程组的某些整体解及其渐近性质

<正> 1.引言 近年来,人们采用了不定常气流方程来计算定常的跨音速气流,取得了一定的成效.在这种计算中,混合型方程组的解被看成为多一个自变量的双曲型方程组解的极限.这启发我们去研究系数和t无关的双曲型方程组的解当t趋向无限时的渐近行为.在本文中,我们利用[2]中的结果,先考虑拟线性对称双曲型方程组,以方程组的充分正为代价,对初始条件作了某些限制以后,证明了这种方程组的混合问题的整体解的存在性.然     

Piecewise linear test functions for stability and instability of queueing networks

We develop the use of piecewise linear test functions for the analysis of stability of multiclass queueing networks and their associated fluid limit models. It is found that if an associated LP admits a positive solution, then a Lyapunov function exists. This implies that the fluid limit model is stable and hence that the network model is positive Harris recurrent with a finite polynomial moment. Also, it is found that if a particular LP admits a solution, then the network model is transient. This revised version was published online in June 2006 with corrections to the Cover Date.     

二次矩阵方程X~2-bX-C=O的正定解

研究二次矩阵方程X2-bX-C=O(b>0,C为n×n阶正定阵)的正定解,证明了解的存在唯一性并且给出了求解方法.     

一个描述血吸虫病的数学模型的周期解

研究一个描述血吸虫病的周期微分方程模型dx/dt=-rx+A/S(t)y,dy/dt=-δ(t)y+B(S(t)-y) x2/1+ x.数值计算发现该系统同时具有渐近稳定的零解和一个正周期解.通过证明该系统解的有界性,并在一个函数空间上构造单调有界序列,进而证明了在一定条件下正周期解的存在性.     

Existence and non‐existence of steady states to a cross‐diffusion system arising in a Leslie predator–prey model

This paper is concerned with a cross‐diffusion system arising in a Leslie predator–prey population model in a bounded domain with no flux boundary condition. We investigate sufficient condition for the existence and the non‐existence of non‐constant positive solution. We obtain that if natural diffusion coefficient of predator is large enough and cross‐diffusion coefficients are fixed, then under some conditions there exists non‐constant positive solution. Furthermore, we show that if natural diffusion coefficients of predator and prey are both large enough, and cross‐diffusion coefficients are small enough, then there exists no non‐constant positive solution. Copyright © 2012 John Wiley & Sons, Ltd.     

OSCILLATIONS OF NONLINEAR DELAY DIFFERENTIAL EQUATIONS——GENERAL LINEARIZED OSCILLA TIONS RESULTS

It is shown that for a wide class of the scalar and vector functional equations of the delay and the neutral type a positive solution exists if and only if the linearized approximating equations are non-oscillatory or, equivalently, the characteristic equations of these linear equations have a real root.     

矩阵方程X-A*XqA=I(0＜q＜1)Hermite正定解的扰动分析

首先证明了非线性矩阵方程X-A~*X~qA=I(0相似文献   

ASYMPTOTIC BEHAVIOR OF SOLUTION FOR NONLOCAL REACTION-DIFFUSION SYSTEM

This paper deals with reaction-diffusion system with nonlocal source. It is proved that there exists a unique classical solution and the solution either exists globally or blows up in finite time. Furthermore, its blow-up set and asymptotic behavior are obtained provided that the solution blows up in finite time.     

Threshold dynamics for a cholera epidemic model with periodic transmission rate

A cholera epidemic model with periodic transmission rate is presented. The basic reproduction number is defined. It is shown that the disease-free equilibrium is globally asymptotically stable and the cholera eventually disappears if the basic reproduction number is less than one. And if the basic reproduction number is greater than one, there exists a positive periodic solution which is globally asymptotically stable. Numerical simulations are provided to illustrate analytical results.