The existence of positive solutions of the nonlinear neutral differential equations in a Banach space

1.IntroductionTheexistenceanduniquenessofsolutionsofdelaydifferentialequationsinaBanachspacehavebeenstudiedbymanyauthors(see[1--4]).Inthispaper,weshallapplythefixedpoillttheoremstoinvestigatetheexistenceofpositivesolutionsofnonlinearneutraldifferentialdifferenceequationsinaBanachspace.LetRbethefieldofrealnumbers,andletR ={tERIt20},to>0,J=[to, co)'ConsiderthenonlinearneutraldifferentialdifferenceequationinaBanachspaceE.mI(x(t)~Zci(t)x(t~ri))' ZPj(t)fj(x(t~D))=0,(1)i=1j=1wherefiEC[P,PI,f…     

周期外力作用下某些二阶非线性微分方程的调和解

本文给出了某些二阶非线性微分方程在周期外力作用下存在调和解的若干定理.这些定理推广了文[1]～[8]的有关结果.     

随机定向收缩及其应用*

作为Altman的定向收缩理论[4,5]和Lee,Padgett的随机收缩理论[1,2]的推广,本文对非线性集值随机算子引入了随机定向收缩概念,利用这一新概念和超限归纳法,我们证明了非线性集值随机算子方程随机解的几个存在性定理.这些定理分别改进和推广了[1,2,4,5,11]中相应的结果.其次,给出了我们的结果对非线性随机积分和微分方程的某些应用.     

The existence of nonoscillatory solutions of higher order nonlinear neutral equations

In this work, we consider the existence of nonoscillatory solutions of variable coefficient higher order nonlinear neutral differential equations. Our results include as special cases some well-known results for linear and nonlinear equations of first, second and higher order. We use the Banach contraction principle to obtain new sufficient conditions for the existence of nonoscillatory solutions.     

一类四阶奇异Sturm-Liouville边值问题正解存在的充分必要条件

研究了一类非线性四阶微分方程奇异Sturm-Liouville边值问题,利用锥上的不动点定理得到了这类方程的C~3[0,1]正解和C~2[0,1]正解存在的充分必要条件.     

一阶中立型差分方程非振动解的分类

讨论了中立型差分方程的非振动解.首先由非振动解的渐进性质把非振动解分成两类.其次分别给出存在这两类非振动解的充分条件.最后给出例子说明定理的应用.     

高阶非线性中立型方程正解的渐近性及存在性

本文利用非线性分析中半序方法和增算子不动点定理，对高阶非线性中立型方程正解的渐近性进行了详细分类，并且给出了各种类型正解存在的充要条件和具体例子．     

随机积分和微分方程解的存在性准则

在[1]中我们已证明了一个一般的随机不动点定理并给出了某些应用,在本文中我们将给出该结果的进一步应用.首先证明了一随机Darbo不动点定理,然后利用此定理在紧性假设下给出了非线性随机Volterra积分方程和非线性随机微分方程Cauchy问题随机解的存在性准则.我们的定理改进和推广了Lakshmikantham[3,4],Vaugham[2],De Blasi和Myjak[5]等人的结果.     

随机积分和微分方程在弱拓扑下解的存在性和比较结果*

在本文中,我们对非线性随机Volterra积分方程在Banach空间的弱拓扑下的随机解证明了几个存在定理.然后作为应用,我们得到了随机微分方程的弱随机解的存在定理.还得到了这些随机方程的极值随机解的存在性和随机比较定理.我们的定理改进和推广了[4,5,10,11,12]中的相应结果.     

Nonoscillation,oscillation and growth of solutions of nonlinear difference equations of second order

Sufficient conditions are obtained which guarantee that all solutions (or all bounded solutions) of a class of second order nonlinear difference equations are nonoscillatory. Oscillation criteria and theorems concerning the growth of solutions are also given.     

Dirichlet problem of quaternionic Monge–Ampère equations

In this paper, the author studies quaternionic Monge–Ampère equations and obtains the existence and uniqueness of the solutions to the Dirichlet problem for such equations without any restriction on domains. Our paper aims to answer the question proposed by Semyon Alesker in [3]. It also extends relevant results in [8] to the quaternionic vector space.     

Banach空间中混合单调脉冲微分-积分方程解的存在性

本文给出了Banach空间中混合单调脉冲微分-积分方程解、耦合最小最大解的存在性定理及单调迭代方法,改进和推广了[1]-[4]的相应结果．     

动态规划中提出的一类泛函方程组公共解和重合解的存在性定理

本文讨论了动态规划中提出的一类更一般的泛函方程组公共解和重合解的存在性问题.本文的结果不仅包含引文[6,7]中相应结果为特例,而且也对引文[2～5]在讨论动态规划的原理和模型时所提出的一类新型的泛函方程给出解的存在性条件.     

增算子不动点定理及其对含间断项非线性脉冲方程的应用

设E是Banach空间,本文在比C[I,E]更一般的Banach空间中得到了几个新的非连续增算子不动点定理.作为应用,我们研究了Banach空间中含间断项的非线性脉冲积分方程和微分方程的最大解和最小解的存在性.     

随机积分方程和微分方程解的存在性和比较结果

本文是[1]的继续.在本文中我们对非线性随机Volterra积分方程给出了解的另一存在性准则,极值解的存在性定理和随机积分不等式的比较定理,这些定理分别推广了Vaughan[2,3]和Lakshmikantham[4,5]的相应结果.     

Existence of solutions for elliptic equations with discontinuous nonlinearities strong resonance at infinity

In the present paper, our main purposes are to study nonlinear elliptic equations with strong resonance at infinity. Some existence theorems for nontrivial solutions are obtained by using some nonsmooth critical point theorems in [N. C. Kourogenis, N. S. Papageorgiou, Nonsmooth critical point theory and Nonlinear elliptic equations at resonance, J. Austral. Math Soc. (Ser. A) 69 (2000) 245–271]. The two of our theorems generalize Theorems 0.1 and 5.2 in [P. Bartolo, V. Benci, D. Fortunato, Abstract critical point theorems and applications to some nonlinear problems with “strong” resonance at infinity, Nonlinear Anal. TMA 7 (1983) 981–1012] to nonsmooth cases. Another theorem is new even if for the smooth case.     

一类非线性悬臂梁方程正解的存在性与多解性

研究了非线性四阶常微分方程u(4)(t)=f(t,u(t),u'(t)),t ∈[0,1]\E在边界条件u(0)=u'(0)=u"(1)=u"'(1)=0下的正解,其中E(∩)[0,1]是一个零测度的闭集,而非线性项,(t,u,u)可以在t∈E时奇异.通过构造适当的积分方程并利用锥上的不动点定理证明了这个方程在满足与n有关的条件下存在n个正解,其中n是某个自然数.     

Banach空间非线性脉冲Volterra型积分方程整体解的存在性定理及应用

利用一个新的比较结果和Ｍｏｎｅｃｈ不动点定理证明了Ｂａｎａｃｈ空间中非线性脉冲Ｖｏｌｔｅｒｒａ型积分方程整体解的存在性定理,并给出了对Ｂａｎａｃｈ空间中一阶脉冲微分方程初值问题的应用,改进了文（１－３）中的主要结果。     

MULTIPLE POSITIVE SOLUTIONS OF NONRESONANT SINGULAR BOUNDARY VALUE PROBLEM OF SECOND ORDER ORDINARY DIFFERENTIAL EQUATIONS

This paper studies the existence of multiple positive solutions of nonresonant singular boundary value problem of second order ordinary differential equations. A sufficient condition for the existence of C[0,1] multiple positive solutions as well as C1[0, 1] multiple positive solutions is given by means of the fixed point theorems on cones.     

The existence theorems of the random solutions for random Hammerstein type nonlinear integral equations

This paper deals with the existence theorems of random solutions of random Hammerstein type nonlinear integral equations. These theorems are proved by using the random fixed-point theorems of cone expansion and compression of random operator discussed by Li and Sheng [1].