1. State Key Laboratory of Coal Conversion; Institute of Coal Chemistry; Chinese Academy of Sciences Taiyuan; Shanxi 030001 PR China
2. University of Chinese Academy of Sciences; Beijing 100049 PR China
3. School of Biological and Chemical Engineering; Zhejiang University of Science and Technology; Hangzhou 310023 P.R. China
4. Zhengzhou Tobacco Research Institute of China National Tobacco Corporation; Zhengzhou 450001 P.R. China