【摘要】 给出常微分方程组周期解存在性的周期上下解方法,利用这种方法得到了生态学中互助系统和竞争系统的非平凡周期解的存在性.更多还原

【Abstract】 In this paper we give the periodic upper-lower solution method for proving the existence of periodic solution of ordinary differential system, using this method we also get nonzero periodic solutions of mutualism models and competitive models in ecology.更多还原