1. Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024, China
2. School of Mathematical Sciences, Chongqing Normal University, Chongqing 401331, China
3. School of Information Science and Technology,Dalian Maritime University, Dalian 116026, China
4. Shaanxi Engineering Research Center of Controllable Neutron Source, School of Science, Xijing University, Xian 710123, China