非线性二阶周期边值问题可描述天体力学、工程和生物中出现的许多周期现象,其广泛的应用引起了许多学者的关注.本文主要研究二阶周期边值问题正解的存在性,其中非线性项包含一阶导数项.设非线性项满足Caratheodory条件,利用零点指数理论和分析技巧,本文建立了二阶周期边值问题正解的存在性定理,推广并改进了一些已知结果.最后给出一个例子说明主要结果.
Many periodic phenomena in celestial mechanics, engineering and biology can be described as nonlinear second order periodic boundary value problems, whose wide applications have attracted much attention of researchers. We mainly discuss in this paper the existence of positive solutions to the second order periodic boundary value problem, where the nonlinear term involves with the first order derivative. We obtain the existence theorems of the positive solutions to the second order periodic boundary value problem by applying Caratheodory conditions on the nonlinear term and employing the zero point index theory and relevant analysis technique. The results extend and improve known results. Finally, an example is given to illustrate the main results.