College of Mathematical Sciences Harbin Engineering University 145 Nan-tong Street Harbin Heilongjiang 150001 People's Republic of China;
School of Mathematics and Statistics Northeast Normal University 5268 Renmin Street Changchun Jilin 130024 People's Republic of China;
School of Mathematics and Statistics Northeast Normal University 5268 Renmin Street Changchun Jilin 130024 People's Republic of China;
CDM LAMPS and Department of Mathematics and Statistics York University 4700 Keele Street Toronto ON M3J 1P3 Canada;
Animal Health Supervision Institute of Xingan League Tiexi North Road Ulanhot Inner Mongolia 137400 People's Republic of China;
