Periodicity And Stability Of Solutions For Several Kinds Of Delay Differential Equations

This thesis of Master is composed of three chapters, which mainly studied the periodicity and stability of solutions for several kinds delay differential equations.In chapter one, by means of the Mawhin's coincidence degree theory and priori estimation, we study the existence of periodic solution for a nonlinear neutral differential equationand some sufficient conditions are established. Our main result improves and generalizes the some known results.Chapter two mainly considers the existence of periodic solution for Rayleigh differential equation with impulse and delay by using the coincidence degreee theory, some sufficient conditions will be established, which are new even for case without impulsive points.In the last chapter, we investigate the 3/2 stability of a nonlinear impulsive differential equation using the theory of analysis, we obtain some sufficient conditions. Our result extends the some know results.