1. State Key Laboratory of Organic-Inorganic Composites; College of Materials Science and Engineering; Beijing University of Chemical Technology; Beijing 100029 China
2. Handan Purification Equipment Research Institute; Handan 056027 China
3. Institute of Metal Research; Chinese Academy of Sciences; Shenyang 110016 China
4. Analysis and Test Centre; Beijing University of Chemical Technology; Beijing 100029 China