1. School of Mathematical Sciences, Jiangsu University, Zhenjiang 212013, Jiangsu, China
2. Department of Physics, Bar-Ilan University, Ramat-Gan 52900, Israel
3. Academy of Military Science, Beijing 100097, China
4. Física de Materiais, Universidade de Pernambuco, Recife, Pernambuco 50100-010, Brazil