1. State Key Laboratory for Mechanical Behavior of Materials
2. Xi'an Jiaotong University
3. Xi'an 710049
4. China
5. Department of Physics and Materials Science
6. College of Physics and Information Technology
7. Shaanxi Normal University
8. Xi'an 710062
9. Department of Physics and Opt-electronic Engineering
10. City University of Hong Kong
11. Kowloon