摘要
本文运用旋转向量场理论，推广了文［１］的一个结论；证明了系统ｄｘｄｔ＝－ｕｘ＋２ｙ＋ｖｘ３＋ｗｘｙ２－２ｙ３，ｄｙｄｔ＝ｘ＋ｘ３在一定条件下具有“８字形奇闭轨”，并且它的外面至少还有一环；适当选取ｕ，ｖ，ｗ的值。
This paper apply theory of rotated vector field to extend a conclusion of the paper , It is proved that under certain condition, the system dxdt=-ux+2y+vx 3+wxy 2-2y 3, dydt=x+x 3 , have a singular closed trajectory of the form “8”, and exist at least a limit cycle outside the singular closed trajectory; Choosing proper values of u,v,w , the system have at least five limit cycles.
出处
《数学杂志》
CSCD
北大核心
1996年第3期381-384,共4页
Journal of Mathematics
