摘要
讨论了一个平面n次系统 ,给出了系统具有Dulac中心的用系数表示的充要条件 .推广了文
We discuss the necessary and sufficient conditions of a plane n-degree system with Dulac′s center,the condition is showed by the coefficient.It is an extension of some results in paper[1].
出处
《山东师范大学学报(自然科学版)》
CAS
2003年第2期4-6,共3页
Journal of Shandong Normal University(Natural Science)