郭治中. 关于Lienard方程极限环唯一性的一个定理[J]. Journal of Xinjiang University (Natural Science Edition in Chinese and English), 1986, (3).DOI:
关于Lienard方程极限环唯一性的一个定理
摘要
对于Lienard方程或其等价系统(其中F(x)=integral from n=0 to ∞f(ξ)d(ξ)的极限环唯一性问题已有许多讨论
但为了保证唯一性
一般都假定方程f(x)=0有且只有两个实根δ-1
δ1
且δ-1δ1<0.本文对此条件做了一点削弱
用较常用的方法证明了一组保证极限环唯一性的充分条件。
Abstract
In this paper we consider the following type of Lienard equation x=y-F(x) Y=-g(x) (A) and give a result on the uniqueness of limit cycles. It is stated as the following theorem: Suppose the system (A) with continuous functions F(x) and g(x) satisfies the following conditions 1°xg(x)>0 for x≠0: G(x) =∫0~xg(ξ)dξ
G (±∞) =+∞
2°f(o)<0 and there are Δ-1<01
such that F(x)<0 for 01 and x-1; F(x)>0 forΔ-1Δ1; F(x)is not-decreasing function when x-1 or x>Δ1. 3°G(Δ-1) = G(Δ1) Then system (A) has a unique stable limit cycle.