1. Key Laboratory of Materials Modification by Laser
2. Ion
3. and Electron Beams (Ministry of Education)
4. Dalian University of Technology
5. Dalian 116024
6. Shenyang National Laboratory for Materials Science (SYNL)
7. Institute of Metal Research (IMR)
8. Chinese Academy of Sciences (CAS)
9. Shenyang 110016
10. China
11. Department of Physics
12. Beijing Normal University
13. Beijing
14. P. R. China