Institution: | [1]School of Physics, China West Normal University, Nanchong 637002, China [2]School of Physics and State Key Laboratory of Nuclear Physics and Technology, PekingUniversity, Beijing 100871, China [3]National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China [4]Xinjiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi 830011, China |