基金supplied by the National Science Funds for Distinguished Young Scientists (30925008) to F.M. Leithe NSFC program (J0930004) to C.Y. Dai+3 种基金the International Cooperation between the Chinese and Slovak Academy of Sciences to F.M. Lei and A. Kritínthe Program of the Ministry of Education of China (206148) to Z.M. Lianthe Program of the Education Department of the Shaanxi Provincial Government (2010JK909)the Program of the Science and Technology Department of Yan’an,China (YAKY200701) to X. Lei