a
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, P. R. China
E-mail: zhj@fjirsm.ac.cn
;
Fax: +86-591-83715030
;
Tel: +86-591-83715030
b
School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, P. R. China