1. School of Navigation and Shipping, Shandong Jiaotong University 1 , Weihai 264200, Shandong, China
2. School of Physics, Harbin Institute of Technology 2 , Harbin 150001, Heilongjiang, China
3. School of Physics and Information Engineering, Shanxi Normal University 3 , Taiyuan 030031, Shanxi, China