作者机构:[1]College of Physics and Electronic Science, Hubei Normal University, Huangshi 435002, China
相关基金:Supported by the National Natural Science Foundation of China under Grant No. 10904033, Natural Science Foundation of Hubei Province under Grant No. 2009CDA145, Educational Commission of Hubei Province under Grant No. D20092204 and the Postgraduate Programme of Hubei Normal University under Grant No. 2007D20