New Razumikhin type theorems for impulsive functional differential equations

In this paper, we investigate stability and boundedness for a class of impulsive functional differential equations by using Liapunov functions and Razumikhin technique. Some new Razumikhin type theorems on stability and boundedness are obtained. The corresponding results obtained recently in [J. Shen, J. Yan, Nonlinear Anal. 33 (1998) 519-531; X. Liu, J. Shen, to appear) are improved.