利用重合度理论中的延拓定理讨论了具有连续时滞和比率型功能反应的非自治扩散捕食系统的全局周期解的存在性,得到了周期解存在的充分条件.
A predator-prey system with continuous time delay and ratio-dependent functional response is studied by using the method of coincidence degree. Sufficient condition is established for persistence of positive periodic solution of the system.