作者机构:[1]Department of Physics, Huainan Normal University, Huainan 232001, China, [2]College of Physics and Information Technology, Guangxi Normal University, Guilin 541004, China, [3]College of Science, China University of Mining and Technology, Xuzhou 221008, China
相关基金:Supported by the National Natural Science Foundation of China (Grant No. 10247005), the Natural Science Foundation of the Anhui Higher Education Bureau (Grant No. KJ2007B187) and the Scientific Research Foundation of China University of Mining and Technology for the Young (Grant No. OK060119).