a
Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, People's Republic of China
E-mail: houxl@sxicc.ac.cn
;
Fax: +86 351 4041153
;
Tel: +86 351 4049501
b
Graduate University of Chinese Academy of Sciences, Beijing, People's Republic of China
c
State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, People's Republic of China