1. Sichuan Research Center of New Materials, 596 Yinhe Road, Shuangliu, Chengdu 610200, PR China
2. Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, PR China
3. Key Laboratory of Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064, China
4. College of Physics, Sichuan University, Chengdu 610065, China