The project supported by National Natural Science Foundation of China under Grant No. 10274063 and the Foundation of Science and Technology Research of the Ministry of Education of China under Grant N
<正> In this work,by means of a generalized method and symbolic computation,we extend the Jacobi ellipticfunction rational expansion method to uniformly constru
<正> The chaotic ratchet effect for Bose-Einstein condensed atoms in an optical lattice is investigated.By usingthe direct perturbation method we obtain the cha