By using the theory of topological degree, we show the existence of positive periodic solution.
然后利用拓扑度的理论确定正周期解的存在性。
参考来源 - 时变种群动力系统解的渐近性态Theorem 2.4.1. System (2.1.2) has a positive periodic solution if T＞T_0=-(ln(1-p_1))/αand is closing to T_0.
定理2．4．1若T＞T_0=-ln(1-p_1)／a且充分接近T_0时，系统(2．1．2)有一个正周期解。
参考来源 - 两类具有Holling·2,447,543篇论文数据，部分数据来源于NoteExpress
得到一些正周期解存在的充分条件。
Some sufficient conditions for the existence of positive periodic solutions are obtained.
利用重合度理论证明系统正周期解的存在性。
The existence of the strictly positive periodic solution of the system is proved by using coincidence degree.
利用重合度理论证明系统正周期解的存在性。
Some results on the existence and multiplicity of positive periodic solutions are derived.
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