1. Institute for Advanced Study Chengdu University Chengdu Sichuan 610106 P.R. China
2. School of Mechanical Engineering Chengdu University Chengdu Sichuan 610106 P.R. China
3. Southwestern Institute of Physics (SWIP) Chengdu Sichuan 610225 P.R. China
4. Institute of Materials China Academy of Engineering Physics Jiangyou Sichuan 621908 P.R. China
5. Institute of Nuclear Science and Technology Sichuan University Chengdu Sichuan 610064 P.R. China