In this paper, some sufficient conditions on the existence of non-trivial periodic solutions of the system dx/dt=e(y), dy/dt=- f(x)h(y)- g(x)are obtained, which not only generalize some known results concerning the Li...In this paper, some sufficient conditions on the existence of non-trivial periodic solutions of the system dx/dt=e(y), dy/dt=- f(x)h(y)- g(x)are obtained, which not only generalize some known results concerning the Lienard system in this direction, but also relax or eliminate some traditional assumptions.展开更多
文摘In this paper, some sufficient conditions on the existence of non-trivial periodic solutions of the system dx/dt=e(y), dy/dt=- f(x)h(y)- g(x)are obtained, which not only generalize some known results concerning the Lienard system in this direction, but also relax or eliminate some traditional assumptions.
