一类带阻尼项的次二次二阶Hamilton系统的周期解
PERIODIC SOLUTIONS OF A CLASS OF SUBQUADRATIC SECOND ORDER HAMILTONIAN SYSTEMS WITH DAMPED VIBRATION

本文研究了一类带阻尼项的二阶Hamilton系统周期解的存在性问题.利用鞍点定理，在新的次二次条件下，获得了一个新的存在性结果，推广并改进了已有文献的相关存在性结论.
In this paper,we study the problems about existence of periodic solutions for second-order Hamiltonian systems with damped vibration.Via saddle point theorem under a new subquadratic condition,an existence theorem is obtained,which extends and improves previously known results