Institution: | 1.Department of General Education, Anhui Xinhua University, Hefei, 230088, Anhui, P. R. China ;2.Department of Applied Mathematics, Nanjing Forestry University, Nanjing, 210037, P. R. China ;3.School of Mathematics (Zhuhai), Sun Yat-sen University, Zhuhai, 519082, Guangdong, P. R. China ;4.Department of Mathematics, Zhejiang Normal University, Jinhua, 321004, Zhejiang, P. R. China ; |