By applying a fixed point theorem, the authors study the existence of positive periodic solutions to a class of differential equations with stated-dependent delay.
运用不动点定理，研究一类具状态依赖时滞的微分方程周期正解的存在性。
2
Using fixed point theorems, in this paper we give sufficient conditions of the existence of bounded mild pseudo almost periodic solution for some semilinear differential equations.
利用不动点理论，给出了一类半线性微分方程有界的调和伪概周期解存在的充分条件。
3
In this paper, by using the fixed point index method, the authors discussed the periodic boundary value problem of first order differential systems.