带变号系数的经典Gelfand模型的正解

考察了经典Gelfand模型的正解的存在与迭代,其中非线性项的系数允许在[0,1]中改变符号。利用单调迭代方法得到了一个正解存在定理,给出了相应的迭代程序和收敛速度。由于这个迭代程序是从零函数开始的,因此它是简单、可行并且有效的。     

一类带有p-Laplacian算子的分数阶积分边值问题的正解与逐次迭代方法

本文研究一类带有p-Laplacian算子并且非线性项f中含有分数阶导数项的分数阶微分方程边值问题的正解的存在性.通过构造上解和下解并利用单调迭代方法,获得该边值问题存在正解的充分条件,并给出一个具体的例子作为应用.     

依赖于一阶导数的(n-1,1)共轭m点边值问题正解的存在性

利用锥上的Krasnoselskii's不动点定理的推广定理,讨论了一类边值问题,给出了相应依赖于一阶导数的非线性n阶m点边值问题至少一个正解的存在性.对于n阶m点边值问题,给出了相应的Green 函数.证明了在非线性项厂满足一定的增长条件下至少存在1个正解.并且给出了一个例子来说明所获得的结果.     

一类具变号非线性项二阶m点边值问题的正解

利用一个新的不动点定理,研究一类具有变号且依赖一阶导数非线性项二阶m点边值问题正解的存在性,得到了正解存在的充分条件.     

一类含有p-拉普拉斯算子的二阶边值问题的单调迭代正解（英文）

研究了一类含有p-拉普拉斯算子的微分方程积分边值问题.运用迭代技巧,给出了这一类边值问题的单调正解,值得感兴趣的是微分方程中的非线性项含有一阶导数.     

β-内酰胺类抗生素/β-内酰胺酶抑制剂合剂临床应用专家共识

本文讨论一类非线性分数阶微分方程积分边值问题正解的存在性.借助于Green函数有关的不等式,通过Krasnoselskii-Zabreiko不动点定理获得该问题正解的存在性结果,并在非线性项无穷远处次线性增长的情况下给出解的迭代序列.     

N阶m点非线性边值问题的三正解的特征值准则

应用算子特征值准则研究了一类高阶多点边值问题多重正解的存在性,其中非线性项满足Caratheodory条件.将特征值准则应用到n阶m点的非线性边值问题,并证明了微分方程至少三正解的存在性.     

一个分数阶方程组积分边值问题的正解（英文）

本文研究一个分数阶方程组积分边值问题.利用不动点指数方法,采用非负凹凸函数刻画非线性项间的耦合行为,并借助单调有界原理,获得该问题正解的存在性结果,并构造了近似解的迭代序列,推广和完善了已有的一些结果.     

奇异非线性边值问题的经典Agarwal-O'Regan方法

改进了奇异非线性边值问题的经典Agarwal-O'Regan方法.利用这个改进的方法建立了奇异非线性(p,n-p)共轭边值问题正解的局部存在性与多解性,其中允许非线性项关于时间和空间变元同时奇异.主要工具是锥拉伸与锥压缩型的Guo-Krasnosel'skii不动点定理和精确先验估计技巧.特别的,考察了非自治奇异非线性二阶、三阶、四阶共轭边值问题.     

一类含参数半正四阶边值问题的正解存在性与多解性

考察了一类含有两个参数的非线性四阶边值问题的n个解和/或正解的存在性,其中允许非线性项有一个非正的函数型下界.在力学和工程上,这类四阶边值问题描述了两端简单支撑的弹性梁的变形.主要工具是锥上的Krasnosel’skii不动点定理和局部化方法.     

Successive iterations for unique positive solution of a nonlinear fractional q-integral boundary value problem

In this paper, under certain nonlinear growth conditions, we investigate the existence and successive iterations for the unique positive solution of a nonlinear fractional $q$-integral boundary problem by employing hybrid monotone method, which is a novel approach to nonlinear fractional $q$-difference equation. This paper not only proves the existence of the unique positive solution, but also gives some computable explicit hybrid iterative sequences approximating to the unique positive solution.     

Successive approximation procedure of optimal tracking control for nonlinear similar composite systems

The optimal tracking control (OTC) problem for a class of affine nonlinear composite systems with similar structure is considered. By using a modeling technique, the nonlinear similar composite system is first transformed into some quasi-decoupled subsystems. Then the high-order, strongly coupled, nonlinear two-point boundary value (TPBV) problem is transformed into a sequence of linear decoupled TPBV problems through a successive approximation procedure. The obtained OTC law consists of an accurate linear term and a nonlinear compensation term which is the limit of the adjoint vector sequence. A suboptimal tracking control law is obtained by truncating a finite iterative result of the adjoint vector sequence as its nonlinear compensation term.     

SUCCESSIVELY ITERATIVE TECHNIQUE OF SIGN-CHANGING SOLUTION TO A NONLINEAR THIRD-ORDER BOUNDARY VALUE PROBLEM

The iterative technique of sign-changing solution is studied for a nonlinear third-order two-point boundary value problem, where the nonlinear term has the time sin-gularity. By applying the monotonically iterative technique, an existence theorem is established and two useful iterative schemes are obtained.     

具有混合单调非线性项的四阶微分方程两点边值问题

讨论了一类具有混合单调非线性项的四阶微分方程两点边值问题,运用一类混合单调算子的不动点定理及"和型"非线性算子的不动点定理,结合单调迭代技巧和格林函数的性质,获得方程正解存在且唯一的充分条件,并构造两个迭代序列收敛于此唯一解.最后,给出具体的例子验证了定理的正确性.     

三阶非线性奇异边值问题正解存在性

研究三阶奇异边值问题-x=f(t,x,x,′x)″,t∈(0,1),x(0)=x(′0)=x(′1)=0,其中f:(0,1)×(0,∞)×R×R→R连续,f在x=0,t=0与t=1处具有奇性.通过运用上下解方法和单调逼近理论,得到了该问题新的正解的存在性结果.     

一类次线性分数微分方程的正解存在性

证明了一类非线性项受幂函数控制的次线性分数微分方程的正解存在性.主要方法是锥拉伸与锥压缩型的Krasnosel’skii不动点定理的局部应用.我们的结论表明该方程可以具有一个正解,只要非线性项在某个有界集上的“高度”是适当的.     

Successively Iterative Technique of a Classical Elastic Beam Equation with Carathéodory Nonlinearity

In this paper, we consider an elastic beam equation where the nonlinear term is a Carathéodory function and the boundary condition is nonhomogeneous. We construct an iterative sequence by the help of monotonic technique and prove that the sequence approximates successively to the solution of the equation under suitable assumptions.     

Successive iteration and positive symmetric solution for a Sturm–Liouville-like four-point boundary value problem with a -Laplacian operator

In this paper, we consider the following Sturm–Liouville-like four-point p-Laplacian boundary value problem with the nonlinear term f depending on the first-order derivative subject to the boundary conditions By using a monotone iterative technique, the existence of symmetric positive solutions and corresponding iterative schemes are obtained.     

On the number of spanning trees in graphs with multiple edges

In this paper, we consider a class of nonlinear matrix equation of the type \(X+\sum _{i=1}^mA_i^{*}X^{-q}A_i-\sum _{j=1}^nB_{j}^{*}X^{-r}B_j=Q\), where \(0<q,\,r\le 1\) and Q is positive definite. Based on the Schauder fixed point theorem and Bhaskar–Lakshmikantham coupled fixed point theorem, we derive some sufficient conditions for the existence and uniqueness of the positive definite solution to such equations. An iterative method is provided to compute the unique positive definite solution. A perturbation estimation and the explicit expression of Rice condition number of the unique positive definite solution are also established. The theoretical results are illustrated by numerical examples.