研究了一类高阶Liénard型方程x(n)(t)+f(x(t))x′(t)+g(x(t-(τt,x(t))))=p(t)的周期解问题,利用Mawhin延拓定理和一个改进的先验估计,获得了一些新的结果.同时也改进并推广了已有文献中的一些结果,所得结果体现了滞量对周期解存在性的影响.
Existence of periodic solutions for a kind of high order Liénard equations x(n)(t)+f(x(t))x′(t)+g(x(t-τ(t,x(t))))=p(t) is studied,and some new results are obtained.The known results in the literature are improved.The result shows the influence of the lag on the existence of periodic solutions.