研究了一类具有比率和单调功能反应的中立型捕食系统.通过利用重合度理论获得了其正周期解存在性的充分条件,推广和改进了已有文献的相关结果.
This paper investigates the existence of positive periodic solutions for a kind of predator-prey system with ratio-dependent and monotonic functional responses.By using a continuation theorem based on coincidence degree theory,some new sufficient conditions of positive periodic solutions of the system are established.Which modifies and generalizes some corresponding publishing results.