%0 Journal Article
%T Center Conditions and Bifurcation of Limit Cycles at the Equatorin a Class of Seven Degree Polynomial Differential System<br>一类七次多项式微分系统的中心条件与赤道极限环分支
%A ZHANG Qi
%A LIU Yirong
%A <br>张齐
%A 刘一戎
%J 系统科学与数学
%D 2008
%I 
%X Center conditions and bifurcation of limit cycles from the equator in a class of polynomial system of degree seven are studied. By converting real planar system into complex system, the recursion formula for the computation of singular point quantities of the infinity are given, and with computer algebra system Mathematica, the first 14 singular point quantities of the infinity are deduced. At the same time, the conditions for the infinity to be a center and 14 degree fine focus are derived respectively. According to the above, a system of degree seven that bifurcates 12 limit cycles from the infinity is constructed.
%K Polynomial system of degree seven
%K infinity
%K singular point quantity
%K bifurcation of limit cycle<br>七次多项式系统
%K 无穷远点
%K 焦点量
%K 奇点量
%K 极限环分支
%K 多项式微分系统
%K 中心条件
%K 赤道
%K 极限环分支
%K DIFFERENTIAL
%K SYSTEM
%K POLYNOMIAL
%K DEGREE
%K CLASS
%K EQUATOR
%K BIFURCATION
%K OF
%K LIMIT
%K CYCLES
%K CONDITIONS
%K 支出
%K 细焦点
%K Mathematica
%K 计算机
%K 递推公式
%K 奇点量
%K 转化
%K 分支问题
%K 无穷远点
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=6E709DC38FA1D09A4B578DD0906875B5B44D4D294832BB8E&cid=37F46C35E03B4B86&jid=0CD45CC5E994895A7F41A783D4235EC2&aid=EDC3B1B62F0655533DD6BDB33D255CBD&yid=67289AFF6305E306&vid=D3E34374A0D77D7F&iid=38B194292C032A66&sid=7979125BBE749348&eid=C1B34927D429E92F&journal_id=1000-0577&journal_name=系统科学与数学&referenced_num=0&reference_num=11