关于二次微分系统Ⅰ类方程的极限环之二

On Limit Cycles of Type I Equation of Quadratic Differential Systems (2)

本文研究了二次微分系统Ⅰ类方程dx／dt=-y＋δx＋lx2＋mxy＋ny2，dy／dt=x的极限环问题，得到了当lι≠0时大范围内存在极限环的条件．

In this paper, the problem on limit cycles of Type I equation of quadratic differential systems dx/dt=-y+δx+lx2+mxy+ny2, dx/dt=x has been researched.It obtained the existential condition of limit cycles on large range when l≠0.