Affiliation: | School of Mathematical and Statistics, Shanxi Datong University, Xingyun Street, 037009, Datong, China,School of Mathematical and Statistics, Shanxi Datong University, Xingyun Street, 037009, Datong, China,School of Mathematical and Statistics, Shanxi Datong University, Xingyun Street, 037009, Datong, China and School of Mathematical and Statistics, Shanxi Datong University, Xingyun Street, 037009, Datong, China |