作者机构:[1]School of Sciences, Nanjing University of Science and Technology, Nanjing 210094, P. R. China
相关基金:Project supported by the National Natural Science Foundation of China (No. 10772085), the Natural Science Foundation of Jiangsu Province (No. BK2007205), the Young Scholar Foundation of Nanjing University of Science and Technology (No. NJUST200504), and the Qing Lan Project of Jiangsu Province