a
State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
E-mail: hpyou@ciac.jl.cn
;
Fax: +86-431-85698041
;
Tel: +86-431-85262798
b
Graduate University of the Chinese Academy of Sciences, Beijing 100049, P. R. China