<正> A quantum secure direct communication scheme using dense coding is proposed.At first,the sender (Alice)prepares four-particle genuine entangled states and
<正> The nonclassical symmetries of a class of nonlinear partial differential equations obtained by the compatibilitymethod is investigated.We show the nonclass
<正> In this paper,bilinear form of a negative order AKNS equation hierarchy is given.The soliton solutionsare obtained through Hiorta's direct method.