1. Department of Physics, Gansu Minzu Normal University, Hezuo, China
2. Key Laboratory of Modern Acoustics, Ministry of Education, Institute of Acoustics of Nanjing University, Nanjing, China
3. College of Physics and Electronnic Enginering, Northernwest Normal University, Lanzhou, China
4. Department of Chemistry and life, Gansu Minzu Normal University, Hezuo, China