1. Research Institute of Advanced Materials Processing Technology, School of Materials Science and Engineering, Beijing University of Technology; No. 100, Pingle Garden, Chaoyang District Beijing 100022 P.R. China
2. Department of Material Science & Engineering; Changsha University of Science & Technology; Changsha 410076 Hunan Province P.R. China
3. China Office, Italy S.O.S. Group; Beijing 100037 P.R. China