一类三次系统在第四象限的极限环

Limit Cycle in the Fourth Quadrant of a Class of Cubic System

文章给出了三次系统()1),(43210-=-+++=xyyyaxyayaxaaxx&&在第四象限极限环的不存在、存在及存在唯一所需要的条件.

The non-existance, existence condition and the only necessary condition for existence of limit cycle in the fourth quadrant of the cubic system:)1(),(243210-=-+++=xyyyaxyayaxaaxx are presented.