一类具有二阶细焦点的二次系统  

A Kind of Quadratic Differential System with a Fine Focus of Order Two

作　　者：王学进 

出　　处：《数学学报（中文版）》1998年第2期399-404,共6页Acta Mathematica Sinica：Chinese Series

摘　　要：本文证明了一类具有二阶细焦点的二次系统（在其二阶细焦点外围）至多存在一个极限环．This paper is intended to prove that there exists at most one limit cycle around the fine focus of order 2 of a kind of quadratic differentiable system.

关 键 词：二次系统 极限环 二阶细焦点 细焦点 

分 类 号：O175.12[理学—数学]