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排序方式: 共有346条查询结果,搜索用时 46 毫秒
1.
This paper deals with non-constant positive steady-state solutionsof a predator-prey system with non-monotonic functional response,also called Holling type-IV interaction terms, and diffusionunder the homogeneous Neumann boundary condition. We first establishpositive upper and lower bounds for such solutions, and thenstudy their non-existence, global existence and bifurcation.2000 Mathematics Subject Classification 35J55, 92D25.  相似文献
2.
ASYMPTOTIC BEHAVIOR OF SOLUTION FOR NONLOCAL REACTION-DIFFUSION SYSTEM   总被引:6,自引:0,他引:6  
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.  相似文献
3.
This paper is devoted to studying the initial value problems of the nonlinear Kaup Kupershmidt equations δu/δt + α1 uδ^2u/δx^2 + βδ^3u/δx^3 + γδ^5u/δx^5 = 0, (x,t)∈ E R^2, and δu/δt + α2 δu/δx δ^2u/δx^2 + βδ^3u/δx^3 + γδ^5u/δx^5 = 0, (x, t) ∈R^2. Several important Strichartz type estimates for the fundamental solution of the corresponding linear problem are established. Then we apply such estimates to prove the local and global existence of solutions for the initial value problems of the nonlinear Kaup- Kupershmidt equations. The results show that a local solution exists if the initial function u0(x) ∈ H^s(R), and s ≥ 5/4 for the first equation and s≥301/108 for the second equation.  相似文献
4.
Global existence and nonexistence for degenerate parabolic systems   总被引:4,自引:0,他引:4  
The initial-boundary value problems are considered for the strongly coupled degenerate parabolic system


in the cylinder , where is bounded and are positive constants. We are concerned with the global existence and nonexistence of the positive solutions. Denote by the first Dirichlet eigenvalue for the Laplacian on . We prove that there exists a global solution iff .

  相似文献

5.
Global Existence in H^2 for a 1-d Non-monotone Fluid   总被引:3,自引:1,他引:2  
吴中林  徐娟娟 《数学季刊》2007,22(2):296-304
In this paper, we prove the existence in H+^2, an incomplete metric subspace of H^2×H^2×H^2, of global solutions to the system for a one-dimensional non-monotone fluid in bounded domainΩ=(0,1). The results in this paper have improved those previously related results.  相似文献
6.
The 2D dissipative quasi-geostrophic equation   总被引:3,自引:0,他引:3  
In this paper, we consider the initial value problem for the 2D critical dissipative quasigeostrophic equation and present results concerning global existence and uniqueness of its solutions in Lq([0, T]; Lp) and Sobolev spaces.  相似文献
7.
This paper is devoted to studying the initial value problem of the modified nonlinear Kawahara equation the first partial dervative of u to t ,the second the third +α the second partial dervative of u to x ,the second the third +β the third partial dervative of u to x ,the second the thire +γ the fifth partial dervative of u to x = 0,(x,t)∈R^2.We first establish several Strichartz type estimates for the fundamental solution of the corresponding linear problem. Then we apply such estimates to prove local and global existence of solutions for the initial value problem of the modified nonlinear Karahara equation. The results show that a local solution exists if the initial function uo(x) ∈ H^s(R) with s ≥ 1/4, and a global solution exists if s ≥ 2.  相似文献
8.
Logistic型脉冲泛函微分方程零解的全局吸引性   总被引:3,自引:0,他引:3       下载免费PDF全文
唐先华  庾建设 《数学学报》2002,45(5):941-952
本文研究Logistic型脉冲泛函微分方程{x‘(t) [1 x(t)]f(t,x(g(t)))=0,t≥0,t≠tк,x(t^ к)=[1 x(tк)]^bк-1,к=1,2,…满足初值条件x(t)=φt,t∈[g(0),0],φ∈PC(t)解的整体存在及全局吸引性,所获结果包含和改进了所有相关的已知结果。  相似文献
9.
退缩抛物型方程解的熄灭时间   总被引:3,自引:0,他引:3  
证明了一类退缩抛物型方程解在有限时刻熄灭,并对解的熄灭时间进行估计  相似文献
10.
By using the continuation theorem of Mawhin's coincidence degree theory, a sufficient condition is derived for the existence of positive periodic solutions for a distributed delay competition modelwhere ri and r2 are continuous w-periodic functions in R+=[0,∞) with ,ai,ci(i =1,2) are positive continuous w-periodic functions in R+=[0,∞),bi (i = 1,2) is nonnegative continuous w-periodic function in R+=[0,∞), w and T are positive constants. Ki,Lt ∈ C([-T,0], (01 88)) and Ki(s)ds = 1,ds - 1. i = 1,2. Some known results are improved and extended.  相似文献
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