EXISTENCE OF PERIODIC SOLUTIONS TO A LINARD EQUATION WITH MULTIPLE DELAYS

In this paper,by a coincidence degree theory,the existence of periodic solutions to a Linard equation with multiple delays is established,which substantially extends some results in the previous literatures.     

PERIODIC SOLUTIONS TO A KIND OF NEUTRAL FUNCTIONAL DIFFERENTIAL EQUATION WITH MULTIPLE DELAYED ARGUMENTS

By employing Mawhin's continuation theorem and some analytic techniques, we study the existence of periodic solutions to a kind of neutral functional differential equation with delays. Our results generalize the corresponding ones of known litera-ture.     

PERMANENCE OF A PERIODIC PREDATOR-PREY SYSTEM WITH GENERAL HOLLING TYPE FUNCTIONAL RESPONSE AND STAGE STRUCTURE FOR PREY

In this paper,we give some sufficient and necessary condition of perma- nence for a periodic predator-prey system with general Holling type functional response and stage structure for preys.By doing this,we improve some known results.