中文摘要：

考虑到某些种群的出生受季节变化的影响,建立了具有脉冲出生和垂直传染的双时滞SEIRS模型.利用频闪映射获得了无病周期解的表达式,并通过比较定理证明了当R0〉1时,无病周期解全局吸引;当R＊0时传染病持续.

英文摘要：

Considering the impact of some populations affected by seasonal changers, a delay SEIRS model with pulse birth and vertical transmission is proposed. Using the discrete dynamical system determined by the stroboscopic map, the exact expression of infection-free periodic solution is obtained. Further- more,by the comparison theorem,it is proved that the infection-free periodic solution is globally attractive when R0〈l and the disease is persistent when R0^＊〉1.