研究一类拟七次解析系统的中心条件与等时中心条件,得到该系统原点的前24个奇点量及系统原点成为中心的条件,再通过对周期常数的计算,得到其复解析系统原点成为等时中心的必要条件,并证明这些条件的充分性.
The centers and isochronous centers of the origin for a class of quasi-seven-degree system were studied.After calculating the first twenty-four singular point values,conditions for the origin were obtained to be a center.Then necessary conditions for the origin to be an isochronous center were found through computing and simplifying the period constants.Moreover,the sufficiency were proved by effective methods.