摘要
给出二次系统I的一类相伴系统在奇点O(0,0)的焦点量公式,证明了O至多为2阶细焦点,δlmn=0时系统在O外围至多有一个极限环,从而说明了系统在细焦点外围至多有一个极限环。最后给出了各个奇点的分支情况及几何特征。
This paper gives the focus values of each order at O（0,0） for a class of accompanying system of the quadratic differential system I, and proves that the system with δlmn = 0 has at most one limit cycle surrounding O, which means that the system has at most one limit cycle surrounding weak focus. Finally the geometric characteristics of all singular points are given.
出处
《系统科学与数学》
CSCD
北大核心
2005年第4期414-422,共9页
Journal of Systems Science and Mathematical Sciences
基金
国家自然科学基金数学天元基金(10426010)福建省自然科学基金(20511052)福建省教育厅科研基金宁德师专重点科研基金
