1. Institute of Applied System Analysis, Faculty of Science, Jiangsu University, Zhenjiang, 212013 Jiangsu, China
2. Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215, USA
3. Department of Physics, Bar-Ilan University, Ramat-Gan 52900, Israel
4. School of Mathematical Sciences, Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing Normal University, Jiangsu 210023, People’s Republic of China