Positive Periodic Solutions to a Kind of Delay FunctionalDifferential Equations with Impulse Effects
WEN Xiangdan1, YUAN Chengjun2, XU Yanhua3
1. Department of Mathematics, College of Sciences, Yanbian University, Yanji 133002, Jilin Province, China;2. College of Mathematics and Computer, Harbin University, Harbin 150086, China;3. School of Mathematics and Statistics, Northeast Normal University, Changchun 130024, China