Jian-Rong Zhou,1 Zhi-Hong Liu,2 and Zhi-Gang Wang3 1 Department of Mathematics, Foshan University, Foshan 528000, Guangdong, China 2 Department of Mathematics, Honghe University, Mengzi 661100, Yunnan, China 3 School of Mathematics and Computing Science, Changsha University of Science and Technology, Yuntang Campus, Changsha, Hunan 410114, China Correspondence should be addressed to Zhi-Gang Wa...