a
Department of Chemistry, Shantou University, Shantou 515063, China
E-mail: kqlu@stu.edu.cn
;
Fax: +86 75482902767
;
Tel: +86 75482903330
b
Guangdong Pharmaceutical University, Guangzhou 510006, China
c
Analysis & Testing Center, Shantou University, Shantou 515063, China