1. Department of Chemistry; Capital Normal University; 100048 Beijing P. R. China
2. The College of Materials Science and Engineering; Beijing University of Technology; 100124 Beijing P. R. China
3. School of Science; Minzu University of China; 100081 Beijing P. R. China
4. Beijing Key Laboratory for Terahertz Spectroscopy and Imaging; Key Laboratory of Terahertz Optoelectronics, Ministry of Education; Department of Physics; Capital Normal University; 100048 Beijing P. R. China
5. School of Food and Chemical Engineering; Beijing Technology and Business University; 100048 Beijing P. R. China