讨论几类具有分布时滞的Volterra积分微分方程正周期解的存在性和多解性问题.利用锥不动点定理,分别获得了这类问题存在正周期解和存在至少两个正周期解的充分条件,推广和改进了已有文献的相关结果.
The existence and multiplicity of the positive periodic solutions for some volterra integro-differenfial equations with distributed delays are discussed. By using the cone fixed-point theorem, some sufficient conditions for the existence and multiplicity of positive periodic solutions are obtained. The results extend and improve the related reports in the literatures.