一类平面五次系统的极限环

The Limit Cycle of a 5-th Order System on the Plane

研究了一类生化反应模型得到了极限环不存在或存在唯一的如下条件：１）若Ｐ＜０，则系统（１）存在唯一稳定的极限环．２）若Ｐ≥０．则系统（１）不存在极限环．

In this paper, we consider a model in biochemic l reaction and obtain the following result: in the first quadrant the unique positive equibrium is globally asymptotically stable when it is stable; and if it is unstable, then (1) has a unique stablelimit cycle.