对于一类多项式系统,给出两类对称条件的推导算法,具体讨论了一类三次系统的中心条件;对于Poincaré型系统,给出一类等时中心的充分条件.
For a class of polynoimial systems, algorithms for deriving two kinds of symmetric conditions are given, and the center conditions for generic cubic systems is investigated in detail. For Poincare systems, we obtain a sufficient condition for the orgin to be isochronous center.