Positive solutions of a nonlinear impulsive equation with periodic boundary conditions

In this paper, we investigate nonlinear second order differential equations subject to linear impulse conditions and periodic boundary conditions. Sign properties of an associated Green’s function are exploited to get existence results for positive solutions of the nonlinear boundary value problem with impulse. Upper and lower bounds for positive solutions are also given. The results obtained yield periodic positive solutions of the corresponding periodic impulsive nonlinear differential equation on the whole real axis.     

On the existence of positive solutions for nonlinear differential equations with periodic boundary conditions

We prove the existence of positive solutions of second-order nonlinear differential equations on a finite interval with periodic boundary conditions and give upper and lower bounds for these positive solutions. Obtained results yield positive periodic solutions of the equation on the whole real axis, provided that the coefficients are periodic.     

Almost periodic solutions for undamped nonhomogeneous delay-differential equations

We first establish a result giving conditions that certain undamped delay differential equations with almost periodic time dependence have unique almost periodic solutions. Using this result we obtain conditions that a second order scalar nonlinear delay differential equation with almost periodic forcing will have a unique almost periodic solution having saddle-type stability properties. These results use the method of averaging.

     

The existence of periodic solutions for a class of nonlinear functional differential equations

This paper is concerned with periodic solutions of first-order nonlinear functional differential equations with deviating arguments. Some new sufficient conditions for the existence of periodic solutions are obtained. The paper extends and improves some well-known results.     

具无穷时滞退化中立型微分系统的周期解(英文)

In this paper,we discuss the periodic solutions of the nonlinear singular neutral differential systems with infinite delay.By using matrix measure and Krasnoselskii＇s fixed point theorem,we obtained the suffcient conditions of the existence of periodic solutions.     

一类四阶非线性微分方程的周期解

本运用Liapunov函数方法，研究了一类四阶非线性微分方程的周期解，得到了存在唯一渐近稳定的周期解的充分条件。     

一类三阶非线性微分方程周期解的存在唯一性

本文运用 L iapunov函数方法 ,研究了一类三阶非线性微分方程的周期解 ,得到了存在唯一渐近稳定的周期解的充分条件     

Search for Periodic Solutions of Highly Nonlinear Dynamical Systems

Numerical-analytical methods for finding periodic solutions of highly nonlinear autonomous and nonautonomous systems of ordinary differential equations are considered. Algorithms for finding initial conditions corresponding to a periodic solution are proposed. The stability of the found periodic solutions is analyzed using corresponding variational systems. The possibility of studying the evolution of periodic solutions in a strange attractor zone and on its boundaries is discussed, and interactive software implementations of the proposed algorithms are described. Numerical examples are given.     

The existence of periodic solutions for nonlinear beam equations on by a para‐differential method

This paper focuses on the construction of periodic solutions of nonlinear beam equations on the d‐dimensional tori. For a large set of frequencies, we demonstrate that an equivalent form of the nonlinear equations can be obtained by a para‐differential conjugation. Given the nonresonant conditions on each finite dimensional subspaces, it is shown that the periodic solutions can be constructed for the block diagonal equation by a classical iteration scheme.     

Existence of Periodic Solutions in Impulsive Differential Equations

In this paper, we are concerned with the problem of existence of periodic solutions for a class of second order impulsive differential equations. By Poincaré-Bohl theorem, we give several criteria to guarantee that the impulsive differential equation has periodic solutions under assumptions that the nonlinear term satisfies the linear growth conditions. Two specific examples are presented to illustrate the obtained results.     

高阶非线性常微分方程组周期解的存在性

本文考虑非线性常微分方程组周期解的存在性,得到了周期解的Ｎａｇｕｍｏ型先验估计,由此在一般性条件下证明了方程组至少有一个Ｔ－周期解,     

The existence of periodic solutions of higher order nonlinear periodic difference equations

Sufficient conditions for the existence of at least one periodic solution of two classes of nonlinear higher order periodic difference equations are established, respectively. The results show us that sufficient conditions for the existence of T ? periodic solutions of difference equation are different from those ones for the existence of T ? periodic solutions of differential equation. Copyright © 2012 John Wiley & Sons, Ltd.     

Positive periodic solutions of nonlinear differential systems with impulses

By using a fixed point theorem of strict-set-contraction, sufficient conditions for the existence of positive periodic solutions of nonlinear differential systems with impulses are obtained. As applications of our results, the existence of positive periodic solutions are established for delay Lotka–Volterra systems with impulses or without impulses.     

Systems of matrix rational differential equations arising in connection with linear stochastic systems with Markovian jumping

In this paper, a class of systems of matrix nonlinear differential equations containing as particular cases the systems of coupled Riccati differential equations arising in connection with control of some linear stochastic systems is considered.The system of differential equations considered in this paper are converted in a suitable nonlinear differential equation on a finite-dimensional Hilbert space adequately choosen.This allows us to use the positivity properties of the linear evolution operator defined by the linear differential equations of Lyapunov type.Our aim is to investigate properties of stabilizing and bounded solutions of the considered differential equations and to obtain some conditions ensuring the existence of such solutions.Conditions providing the existence of a maximal solution (minimal solution respectively) with respect to some classes of global solutions are presented. It is shown that if the coefficients of the equations are periodic functions all these special solutions (stabilizing, maximal, minimal) are periodic functions, too.Whenever possible the probabilistic arguments were avoided and so the results proved in the paper appear as results in the field of differential equations with interest in themselves.     

具无穷时滞中立型高维非线性系统的周期解

通过构造算子利用Krasnoselskii不动点定理和线性系统的指数二分性讨论了一类具有无穷时滞非线性中立型高维周期微分系统的周期解存在性问题．得到保证系统存在周期解的新的充分条件．     

On the solvability of periodic boundary value problems with impulse

In this work we obtain some new results concerning the existence of solutions to an impulsive first-order, nonlinear ordinary differential equation with periodic boundary conditions. The ideas involve differential inequalities and Schaefer's fixed-point theorem.     

Differential systems, the mapping over period for which is represented by a product of three exponential matrixes

For some periodic differential systems the sufficient conditions of a representation of the mapping over period as a product of a three exponential matrix of the special aspect are obtained. Obtained results are used for research of problems of the existence and stability of periodic solutions of nonlinear systems and the asymptotic orbital stability of cycles of autonomous differential systems.     

Existence of periodic solutions of nonlinear systems of differential equations with impulse effect

Sufficient conditions for the existence of periodic solutions of nonlinear systems of differential equations with impulses in a canonic domain have been found in the paper.     

多变时滞 n 阶非线性中立型泛函微分方程周期解存在性

该文利用重合度理论,研究多变时滞 n 阶非线性中立型泛函微分 方程周期解存在性,给出这类方程存在周期解的一个较一般的判别法与四个充分性定理.     

一个非线性时滞偏微分方程种群模型的稳定性与周期性

讨论了一个具有年龄结构非线性非自治时滞偏微分方程种群模型解的渐近性态,得到了零解稳定以及周期解存在的充分条件.