[1] Xian Univ Technol, Sch Mat Sci & Engn, Xian 710048, Shaanxi, Peoples R China
[2] Sichuan Univ, Minist Educ, Key Lab Radiat Phys & Technol, Chengdu 610064, Sichuan, Peoples R China
[3] Sichuan Univ, Sch Phys Sci & Technol, Chengdu 610064, Sichuan, Peoples R China