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1.
刘亚成  辛洪学 《数学学报》2000,43(5):847-854
本文研究 Fujita型反应扩散方程组的初值问题:ut-△u=a1u~α1-1u+b1v~β1-1v,vt-△v=a2u~α2-1u+b2v~β2-1v,u(X,0)=u0(X),V(X,0)=V0(X),(X,t)R~N x R~+,其中 ai,bi≥ 0, αi,βi≥ 1(i= 1,2),给出了非负整体 L~p解与古典解存在性与非存在性的一系列充分条件,并讨论了解的渐近性质.本文所用方法和所得结果与已有的工作[1-4],有很大的不同,不但在某些方面推广了[1-5],而且从某些方面改进了[1]的结果。  相似文献   

2.
一类拟线性二阶微分方程解的振动与非振动的判定   总被引:4,自引:0,他引:4  
杨小京 《数学学报》2001,44(2):311-318
本文讨论了拟线性微分方程(p(x'))'+q(t)p(x)=0,t≥t0,q(t)≥0(这里 p(u)=|u|p-1u,p>0是常数)的解的振动与非振动条件,并改进了文献[2]的结果.  相似文献   

3.
Summary We establish new comparison theorems on the oscillation of solutions of a class of perturbed half-linear differential equations. These improve the work of Elbert and Schneider [6] in which connections are found between half-linear differential equations and linear differential equations. Our comparison theorems are not of Sturm type or Hille--Wintner type which are very famous. We can apply the main results in combination with Sturm's or Hille--Wintner's comparison theorem to a half-linear differential equation of the general form (|x'|α-1x')' + a(t) |x|α-1x = 0.  相似文献   

4.
研究三维微分系统:u′1=a1(t)|u2|λ1sgn u2,u′2=a2(t)|u3|λ2sgn u3,u′3=-a3(t)|u1|λ3sgn u1.假设λi(i=1,2,3)是正的常数,ai(t)(i=1,2,3)在区间[0,∞)上是正的连续函数,根据u的分量ui的特殊渐近条件定义了正值解的几种类型。系统满足条件∫0∞ai(t)dt=∞,i=1,2.  相似文献   

5.
张桂宜  沈尧天 《数学学报》1998,41(4):851-858
本文给出RN(N3)中有界光滑区域Ω上的拟线性椭圆型方程:-∑Ni=1xi·|Du|p-2uxi=λ|u|p-2u+a(x)|u|p-2u+f(x,u),x∈Ω(λ>0,p=Np/(N-p),2p<N)在边界条件:-|Du|p-2Dνu|Ω=ψ(x)|u|q-2u(q=(N-1)p/(N-p))下的多解性结果.  相似文献   

6.
We establish new Kamenev-type oscillation criteria for the half-linear partial differential equation with damping under quite general conditions. These results are extensions of the recent results developed by Sun [Y.G. Sun, New Kamenev-type oscillation criteria of second order nonlinear differential equations with damping, J. Math. Anal. Appl. 291 (2004) 341-351] for second order ordinary differential equations in a natural way, and improve some existing results in the literature. As applications, we illustrate our main results using two different types of half-linear partial differential equations.  相似文献   

7.
关于Fujita型反应扩散方程组的Cauchy问题   总被引:5,自引:1,他引:5  
张凯军  王亮涛 《数学学报》1997,40(5):717-732
本文研究Fujita型反应扩散方程组ut-Δu=α1|u|q1-1u+β1|v|p1-1v,(x∈RN,t>0),vt-Δv=α2|u|q2-1u+β2|v|p2-1v,u(x,0)=u0(x)0,v(x,0)=v0(x)0,(x∈RN)Lp解的整体存在性和有限时间Blow up问题.这里qi>1,pi>1(i=1,2),α10,α2>0,β1>0,β20,1p+∞.  相似文献   

8.
Robin型二阶m 点边值问题正解的存在性   总被引:2,自引:0,他引:2       下载免费PDF全文
设 a∈C[0,1], b∈C([0,1],(-∞, 0)). 设\-1(t)为线性边值问题  u″+a(t)u′+b(t)u=0, u′(0)=0,\ u(1)=1  的唯一正解. 该文研究非线性二阶常微分方程m 点边值问题  u″+a(t)u′+b(t)u+h(t) f(u)=0,\= u′(0)=0, u(1)-∑[DD(]m-2[]i=1[DD)]α\-i u(ξ\-i)=d  正解的存在性. 其中 d 为参数, ξ\-i∈(0,1), α\-i∈(0,∞) 为满足 ∑[DD(]m-2[]i=1[DD)]α\-i\-1(ξ\-i)<1的常数, i∈{1,\:,m-2}. 在适当的条件下证得: 存在正常数 d\+*, 使 当0d\+*时无正解.  相似文献   

9.
We consider the magnetic nonlinear Schrödinger equations $\begin{array}{ll}{\left(-i\nabla + sA\right)^{2} u + u \, = \, |u|^{p-2}\, u, \quad p \in (2, 6),} \\ \quad \quad {\left(-i\nabla + sA\right) ^{2}u \, = \, |u|^{4}\, u,}\end{array}$ in ${\Omega=\mathcal{O}\times \mathbb{R}}We consider the magnetic nonlinear Schr?dinger equations
ll(-i?+ sA)2 u + u   =  |u|p-2 u,     p ? (2, 6),         (-i?+ sA) 2u   =  |u|4 u,\begin{array}{ll}{\left(-i\nabla + sA\right)^{2} u + u \, = \, |u|^{p-2}\, u, \quad p \in (2, 6),} \\ \quad \quad {\left(-i\nabla + sA\right) ^{2}u \, = \, |u|^{4}\, u,}\end{array}  相似文献   

10.
吳卓人 《数学学报》1956,6(3):476-489
<正> 設函數w=f(z)在單位圓|z|<1中是正則的.f(0)=0,f′(0)=1.假如f(z)是單葉的,那末w=f(z)映照|z|<1於w平面上的單葉的像D_f.記這種單葉函數的全體為S.若D_f以原點w=0為星形中心,就稱f(z)是|z|<1中的星  相似文献   

11.
In this paper, we consider the complex Ginzburg-Landau equation (CGL) in three spatial dimensions u_t = ρu + (1 + iϒ )Δu - (1 + iμ) |u|^{2σ} u, \qquad(1) u(0, x) = u_0(x), \qquad(2) where u is an unknown complex-value function defined in 3+1 dimensional space-time R^{3+1}, Δ is a Laplacian in R³, ρ > 0, ϒ, μ are real parameters. Ω ∈ R³ is a bounded domain. We show that the semigroup S(t) associated with the problem (1), (2) satisfies Lipschitz continuity and the squeezing property for the initial-value problem (1), (2) with the initial-value condition belonging to H²(Ω ), therefore we obtain the existence of exponential attractor.  相似文献   

12.
刘醴泉 《数学学报》1957,7(2):313-326
<正> 设函数 f(z)=z+a_2Z~2+…在单位圆|z|<1上是正则的单叶的.这种函数的全体形成一族 S.S 中满足条件|f(z)|1上是单叶的,除开极点ζ=∞是正则的.这种函数的全体形成一族∑.∑中满足条件|F(ζ)|>R的函  相似文献   

13.
研究奇异拟线性椭圆型方程{-div(|x|~(-ap)|▽u|~(p-2)▽u) + f(x)|u|~(p-2) = g(x)\u|~(q-2)u + λh(x)|u|~(r-2),x R~N,u(x) 0,x∈ R~N,其中λ0是参数,1pN(N3),1rpgp*=0a(N—p)/p,p*=Np/{N~pd),aa+l,d=a+l-60,权函数f(x),g(x),h(x)满足一定的条件.利用山路引理和Ekeland变分原理证明了问题至少有两个非平凡的弱解.  相似文献   

14.
This paper is concerned with the following n-th ordinary differential equation:{u~(n)(t)=f(t,u(t),u~(1)(t),···,u~(n-1) (t)),for t∈(0,1),u~(i) (0)=0,0 ≤i≤n3,au~(n-2)(0)du~(n-1)(0)=0,cu~(n-2)(1)+du~(n-1)(1)=0,where a,c ∈ R,,≥,such that a~2 + b~2 0 and c~2+d~20,n ≥ 2,f:[0,1] × R → R is a continuous function.Assume that f satisfies one-sided Nagumo condition,the existence theorems of solutions of the boundary value problem for the n-th-order nonlinear differential equations above are established by using Leray-Schauder degree theory,lower and upper solutions,a priori estimate technique.  相似文献   

15.
Sobolev临界增长椭圆方程注   总被引:1,自引:0,他引:1  
饶若峰 《大学数学》2006,22(5):41-44
利用空间H10(Ω)的正交分解和极小值原理给出了具临界指数2*的椭圆方程-Δu=λ1u-|u|2*-2u+g(x,u)+h(x)1解的存在性定理,这里次临界项g(x,u)关于u是非线性的,λ1为算子-Δ在H10(Ω)中最小特征值.特别当h≡0时,本文还获得了非零解的存在性结论.  相似文献   

16.
徐志庭 《数学学报》2004,47(6):1099-110
利用Riccati技巧,对二阶含阻尼项椭圆型微分方程∑i,j=1N Di[aij(x)Djy]+∑i=1N bi(x)Diy+q(x)f(y)=0给出解非振动的必要条件,进而建立上述方程振动的充分准则.  相似文献   

17.
By using vector Riccati transformation and averaging technique, some oscillation criteria for the quasilinear elliptic differential equation of second order, ΣNi,j=1Di[Ψ(y)Aij(x)|Dy|^p-2Djy]+p(x)f(y)=0, are obtained. These theorems extend and include earlier results for the semilinear elliptic equation and PDE with p-Laplacian.  相似文献   

18.
研究了高阶线性微分方程f~(k)+A_(k-1)(z)f~(k-1)+…+A_1(z)f′+A_0(z)f=0的非零解f,及其一阶、二阶导数,f~(i)(i=1,2)的不动点性质,这里A_j(z)(j=0,1,…k-1)为亚纯函数,得到了若δ(∞,A_0)>0,且满足max{i(A1),i(A2),…,i(A_(k-1))}相似文献   

19.
In this paper we are concerned with the nonlinear eigenvalue problem consisting of the functional differential equation with p -Laplacian operator, ( { p ( u '))' + u a ( t ) f ( t , u t ) = 0, { p ( s ) = | s | p m 2 s , p > 1, the initial condition, u ( s ) = } ( s ), m h s h 0, and the boundary condition, u (0) = 0 = u (1), where a ( t ) is allowed to be singular at the end points of (0, 1). Our results apply to more than just the sublinear and superlinear cases discussed in other references.  相似文献   

20.
D Ranee avtorom byli postroeny sistemy vida $$e^{-i lambda_n t} \exp (-a|t|^\alpha), \quad \lambda_n \in \Lambda; \quad a>0, \ \alpha>1,\leqno(1)$$ polnye i minimal\cprime nye v prostranstvakh $L^p ({\bf R})$ $(L^p ({\bf R}_+))$ pri $p\ge 2$. V danno\u i\ stat\cprime e stroyat\cydot sya sistemy (1), obladayushchie takim svo\u istvom v prostranstvakh $L^p({\bf R})$ $(L^p ({\bf R}_+))$, $1\le p <2$ i $C_0 ({\bf R})$ $(C_0 ({\bf R}_+))$.  相似文献   

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