1. State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, P. R. China
2. University of Chinese Academy of Sciences, Beijing 100049, P. R. China
3. Institute of Modern Optics, College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300350, P. R. China