一类奇次微分系统的极限环研究

The study of limit cycles for a class of odd power differential systems

借助德拉格辽夫定理、张芷芬定理以及Dulac函数和特殊曲线对微分系统 x =-y +δx+xy +lx2n+ 1 , y=x2n- 1进行研究 ,得到其极限环的存在性。

By analyzing qualitatively the differential systems=-y+δx+xy+lx 2n+1 , =x 2n-1  the sufficient conditions for the existence,uniqueness and nonexistence of limit cycles for the systems are obtained.