Affiliation: | 1. School of Applied Mathematics, Nanjing University of Finance and Economics, Nanjing 210023, Jiangsu, PR China;2. Department of Mathematics, Cankaya University, 06530 Balgat, Ankara, Turkey;3. Institute of Space Sciences, Magurele–Bucharest, Romania;4. College of Mathematics and Software Science, Sichuan Normal University, Chengdu 610066, Sichuan Province, PR China |