给出一类四次多项式系统原点的前8个奇点量,由奇点量导出焦点量,得到该系统原点成为8阶细焦点的条件,证明该系统从原点可以分支出8个极限环.
The bifurcation of limit cycles from a weak focal is investigated for a quartic polynomial system. The first 8 singular point values are given at the origin of system,and the focal values can be derived from the singular points, then the conditions that the origin is an 8-order weak focal is obtained. Finally, it is proved that this system has 8 limit cycles in the neighborhood of the origin.