一类具有奇异灵敏度的logistic趋化系统解的渐近行为

本文在无边界流的光滑有界区域$\Omega\subset\mathbb{R}^n~(n>2)$上研究了具有奇异灵敏度及logistic源的抛物-椭圆趋化系统$$\left\{\begin{array}{ll}u_t=\Delta u-\chi\nabla\cdot(\frac{u}{v}\nabla v)+r u-\mu u^k,&x\in\Omega,\,t>0,\\ 0=\Delta v-v+u,&x\in\Omega,\,t>0\end{array}\right.$$ 其中$\chi$, $r$, $\mu>0$, $k\geq2$. 证明了若当$r$适当大, 则当$t\rightarrow\infty$时该趋化系统全局有界解呈指数收敛于$((\frac{r}{\mu})^{\frac{1}{k-1}}, (\frac{r}{\mu})^{\frac{1}{k-1}})$.     

具源项的奇异扩散方程解的存在性及渐近性

讨论了一类具源项的奇异扩散方程的第二初边值问题,证明了经典解的存在性以及时间充分大时解的渐近性质.     

Global Asymptotic Behavior of a Predator-Prey Diffusion System with Beddington-DeAngelis Function Response

In this paper, we study a class of reaction-diffusion systems with Beddington- DeAngelis function response. The global asymptotic convergence is established by using the comparison principle and the method of monotone iterations, which is via successive improvement of upper-lower solutions function.     

Asymptotic Behavior of Solution to Some Models Involving Two Species All with Chemotaxis

This paper is concerned with the asymptotic behavior of solution to the following model involving two species all with chemotaxis：{αp/αt=Dp△（p△lnp/w）,αp/αt=Dq△（q△lnq/w）,αw/αt=βp-δw,p△ln（p/w）.^-n=q△ln（q/w）.^-n=0.We prove that the solution exists globally asβ ≥ 0. Asβ 〈 0, whether the solution exists globally or not depends on the initial data. By function transformation and compari- son, the asymptotical behavior of the solution is studied.     

Oscillatory and Asymptotic Behavior for Second Order Quasilinear Difference Equations

1 IntroductionConsider the second order quasilinear difference equationA(g(Ay.--l)) + f(n,y.) = 0, for n E N(no), (l'l)where A is defined by Ay. = Vn+1--yn, n E N(no) = {no, no + 1,'' }, nO E N = {l, 2,'. }.The following hold throughout the paPer:(H0) (i) g: R-R is a continuous increasing fUnction with propertiessgng(y) = sgny) g(R) = R;(il) f: N(no) x R--+ R is continuous as a function of y E R;(iii) yf(n,y) > 0 for n E N and y / 0.By a solution of the equation (1.l) we mean a non…     

非线性奇摄动系统的渐近性态

The asymptotic behavior of solution for a n-dimensional nonlinear singularly perturbed system is studied. Under the appropriate assumptions, the existence of solution for the system is proved and the estimation of the solution is given using the method of differential inequalities.     

带可变密度和吸收项的退化抛物方程解的局部性和渐近行为

研究一类在非均匀介质中带可变系数和吸收项的非线性退化抛物方程Cauchy问题解的局部性质和渐近行为,得到了解有局部性的条件.同时,证明了解的渐近性质,发现了有限时刻的熄灭现象.这些结果改进和推广了相关问题的最新成果.     

一个带非局部源的反应扩散方程组解的存在性和渐近性态

本文研究带非局部源的半线性反应扩散方程组,并通过建立比较定理,利用Schauder不动点定理证明古典解的存在唯一性,得到了解的爆破点集与解的渐近性态.     

Blowup and Asymptotic Behavior of a Free Boundary Problem with a Nonlinear Memory

In this paper, we investigate a reaction-diffusion equation $u_t-du_{xx}=au+\int_{0}^{t}u^p(x,\tau){\rm d}\tau+k(x)$ with double free boundaries. We study blowup phenomena in finite time and asymptotic behavior of time-global solutions. Our results show if $\int_{-h_0}^{h_0}k(x)\psi_1 {\rm d}x$ is large enough, then the blowup occurs. Meanwhile we also prove when $T^*<+\infty$, the solution must blow up in finite time. On the other hand, we prove that the solution decays at an exponential rate and the two free boundaries converge to a finite limit provided the initial datum is small sufficiently.     

非局部退化拟线性抛物型方程组解的爆破和整体存在性

该文采用弱上下解方法和正则化技巧,研究了一类非局部退化抛物型方程组解的爆破和整体存在性,给出了爆破指标,并对非退化情形m=n=1,p_1=q_1=0,p_2q_21给出了一致爆破速率.     

一类具有跳跃层的非线性反应扩散系统的渐近行为

讨论了一类具有跳跃层的反应扩散系统.首先,求出了问题的外部解.其次,引入伸长变量,构造了跳跃层校正项.最后,利用微分不等式理论,得到了原问题解的一致有效的渐近展开式.从而研究了相应问题的解的渐近性态.     

Asymptotic Behavior of Solutions to a Class of Semilinear Parabolic Equations with Boundary Degeneracy

This paper concerns the asymptotic behavior of solutions to one-dimensional semilinear parabolic equations with boundary degeneracy both in bounded and unbounded intervals. For the problem in a bounded interval, it is shown that there exist both nontrivial global solutions for small initial data and blowing-up solutions for large one if the degeneracy is not strong. Whereas in the case that the degeneracy is strong enough, the nontrivial solution must blow up in a finite time. For the problem in an unbounded interval, blowing-up theorems of Fujita type are established. It is shown that the critical Fujita exponent depends on the degeneracy of the equation and the asymptotic behavior of the diffusion coefficient at infinity, and it may be equal to one or infinity. Furthermore, the critical case is proved to belong to the blowing-up case.     

Existence of Solutions for a Parabolic System Modelling Chemotaxis with Memory Term

In this paper, we come up with a parabolic system modelling chemotaxis with memory term, and establish the local existence and uniqueness of weak solutions. The main methods we use are the fixed point theorem and semigroup theory.     

A Quasilinear Parabolic System with Nonlocal Boundary Conditions and Localized Sources

This paper investigates the properties of solutions to a quasilinear parabolic system with nonlocal boundary conditions and localized sources. Conditions for the existence of global or blow-up solutions are given. Global blow-up property and blow-up rate estimates are also derived.     

空间中渐近非扩张型映射的渐近行为

Let X be a uniformly convex Banach space X such that its dual X^＊ has the KK property. Let C be a nonempty bounded closed convex subset of X and G be a directed system. Let ={Tt ： t ∈ G} be a family of asymptotically nonexpansive type mappings on C. In this paper, we investigate the asymptotic behavior of {Ttx0 ： t∈ G} and give its weak convergence theorem.     

含最大值项二阶中立型差分方程的渐近性

考虑含最大值项二阶中立型差分方程其中{an},{pn}和{qn}为实数列,k和■为整数且k≥1,■≥0,我们研究了方程(*)非振动解的渐近性．通过例子说明了含最大值项的方程和相应的不含最大值项方程之间的区别．     

一类二元离散神经网络模型的渐近性

本文考虑的是一类具有分段常数非线性时滞差分系统,该系统可作为二元人工神经网络模型的离散形式,本文得到了系统解的渐近性的一些结果。     

一类泛函微分方程的全局渐近状态

本文考虑形如x(t)=diag(x(t))g(x_t)的泛函微分方程.我们的主要结果(定理3.1)指明,若g满足一定的条件,则当初始函数属于C([-r,0],R~n)的某个子集时所述方程的所有解都收敛于同一平衡状态.