一类中心对称的三次Lienard方程的极限环分布

DISTRIBUTIONS OF LIMIT CYCLES FOR A CLASS OF CUBIC LIENARD EGUATIONS WITH CENTER SYMMETRY

讨论了一类中心对称的三次Lienard方程 (带二次阻尼项 )的极限环分布 ,证明了至多存在三个极限环 。

We discuss distributions of limit cycles for a class of cubic Lienard equations of center symmetry(with quadratic damping)and prove that there are at most three limit cycles and seven different opposite positions.