Institution: | aPhysics Department, Yunnan University, Kunming 650091, PR China;bPhysics Department, Yuxi Normal College, Yuxi 653100, PR China;cNational Astronomical Observatories, Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011, PR China;dPhysics Department, Dezhou University, Dezhou 253023, PR China;ePhysics Department, Guangxi University, Nanning, Guangxi 530004, PR China |