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1.
戚仕硕 《东北数学》2002,18(1):63-72
The present paper tackles two-point boundary value problems for fourth-order differential equations as follows:{u′″(t)=a(t)f(u(t)),t∈[0,1],;a1u(0)-b1u′(0)-c1u(1) d1u′(1)=0,;a2u″(0)-b2u′″(0)=c2u″(1) d2u′″(1)=0.Several existence theorems on multiple positive solutions to the problems are obtained,ad some examples are given to show the validity of these results.  相似文献   

2.
In this paper, we prove a new fixed point theorem in cones and obtain the existence of triple positive solutions for a class of quasi-linear three-point boundary value problems.  相似文献   

3.
A two-point boundary value problem with a non-negative parameter Q arising in the study of surface tension induced flow of a liquid metal or semiconductor is studied. We prove that the problem has at least one solution for Q≥0.This improves a recent result that the problem has at least one solution for 0 ≤Q≤13.21.  相似文献   

4.
This paper is devoted to the study ofthe existence of single and multiple positive solutions forthe first order boundary value problem x′= f(t,x),x(0)=x(T),where f ∈ C([0,T]×R).In addition,weapply our existence theorems to a class of nonlinear periodic boundary value problems with a singularity at theorigin.Our proofs are based on a fixed point theorem in cones.Our results improve some recent results in theliteratures.  相似文献   

5.
The paper presents the conditions which guarantee that for some positive value of μ there are positive solutions of the differential equation (Ф(x'))'+μQ(t, x, x') = 0 satisfying the Dirichlet boundary conditions x(0) = x(T) = 0. Here Q is a continuous function on the set [0, T] × (0, ∞) ~ (R / {0}) of the semipositone type and Q is singular at the value zero of its phase variables.  相似文献   

6.
The existence of n positive solutions for a class of third-order three-point boundary value problems is investigated,where n is an arbitrary natural number,The main tool is Krasnosel‘skii fixed point theorem on the cone.  相似文献   

7.
In this paper, we show that the method of monotone iterative technique is valid to obtain two monotone sequences that converge uniformly to extremal solutions to second order periodic boundary value problems and periodic solutions of functional difference equations. We obtain some new results under the lower solution a and upper solution βwith α≤β.  相似文献   

8.
9.
Let D and D′ be domains in real Banach spaces of dimension at least 2. The main aim of this paper is to study certain arc distortion properties in the quasihyperbolic metric defined in real Banach spaces. In particular, when D′ is a QH inner ψ-uniform domain with ψ being a slow (or a convex domain), we investigate the following: For positive constants c,h,C,M, suppose a homeomorphism f: DD′ takes each of the 10-neargeodesics in D to (c, h)-solid in D′. Then f is C-coarsely M-Lipschitz in the quasihyperbolic metric. These are generalizations of the corresponding result obtained recently by Väisälä.  相似文献   

10.
This paper deals with the initial boundary value problem for the Boltzmann-Poisson system, which arises in semiconductor physics, with absorbing boundary. The global existence of weak solutions is proved by using the stability of velocity averages and the compactness results on L1-theory under weaker conditons on initial boundary values.  相似文献   

11.
通过构造一个特殊的锥,利用范数形式的锥拉伸锥压缩不动点定理,在允许非线性项变号无下界且没有任何单调性假设的条件下,得出了一类高阶(k,n-k)共轭两点边值问题方程组正解的存在性结论.  相似文献   

12.
奇异(k,n-k)共轭边值问题的正解   总被引:10,自引:1,他引:10  
蒋达清 《数学学报》2001,44(3):541-548
对固定的 1≤ k≤n-1,在对 f(t,y)更弱的条件下,本文重新建立了奇异边值问题正解的存在性.允许f(t,y)在y=0,t=0和t=1处具有奇性,本文只用到格林函数的正性和一个锥不动点定理,并且构造了格林函数的精确表达式.  相似文献   

13.
本文讨论了(k,n-k)共轭边值问题的正解存在性,其中λ是一个正参数。应用Krasnoselsii‘s的不动点定理得到了正确存在准则。  相似文献   

14.
By applying the fixed-point theorem of strict-set-contraction,this paper establishes the existence of one solution or one positive solution to the generalized Sturm-Liouville m-point boundary value problem in Banach spaces.  相似文献   

15.
(k,n-k)共轭边值问题正解的连通分支   总被引:1,自引:0,他引:1  
讨论了(k,n-k)共轭边值问题。在适当的非线性项零点假设下,得到了多正解的存在性,给出了正解的全局连通分支。  相似文献   

16.
Banach空间中二阶微分方程三点边值问题的正解   总被引:2,自引:0,他引:2  
周友明 《应用数学》2005,18(3):446-454
本文在Banach空间中讨论二阶非线性微分方程的三点边值问题:-u″=a(t)f(u),u(0)=θ,u(1)=cu(ξ)。运用严格集压缩算子的不动点定理,在f超线性增长或次线性增长的前提下,证明了上述问题正解的存在性和多重正解的存在性。  相似文献   

17.
通过利用Krasnosel′skii不动点定理的扩充定理,对于一类含导数的非线性二阶m-点边值问题(1.1)+(1.2)u″(t)+f(t,u(t),u′(t))=0,0相似文献   

18.
在不假定非线性项f单调的前提下研究一类混合型泛函微分方程边值问题.利用锥上的不动点定理获得了所考虑问题的正解的存在性和多解性结果.  相似文献   

19.
应用锥理论和不动点指数方法,在与相应的线性算子第一特征值有关的条件下,获得奇异超线性(k,n-k)多点边值问题正解的存在性结果,推广和改进了已有的主要结论.  相似文献   

20.
讨论了下列变号(k,n-k)共轭边值问题(SCBVP)正解的存在问题{(-1)(n-k)u(n)(t)=f(t,u(t)),0t1,u(i)(0)=0,0≤i≤k-1,u(j)=0,0≤j≤n-k-1,其中n≥2,1kn-1.对于0t1,非线性项f允许变号,即本文允许非线性项f取负值并且可以无下界.本文利用不动点指数定理,在无任何单调性假设条件下,得到了边值问题正解的存在性结论.  相似文献   

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