1. Department of Forensic Science , People’s Public Security University of China , Beijing 100038 , PR China
2. First Research Institute of the Ministry of Public Security , Beijing 100048 , PR China
3. School of Mathematic and Physical Science, Xuzhou Institute of Technology , Xuzhou 221111 , PR China
4. School of Physics, Beijing Institute of Technology , Beijing 100081 , PR China , Phone: +86 1068918559