On existence of positive periodic solutions of a kind of Rayleigh equation with a deviating argument

摘要

summary:The existence of positive periodic solutions for a kind of Rayleigh equation with a deviating argument $$ x''(t)+ f(x'(t))+ g(t,x(t-\tau (t)))= p(t) $$ is studied. Using the coincidence degree theory, some sufficient conditions on the existence of positive periodic solutions are obtained.