**Acknowledgements**

The author gratefully acknowledges the financial supports from the National Natural Science Foundation of China (Grant No. 61701159, JZ2017GJQN1131), the Natural Science Foundation of Anhui Province (Grant No. 101413246, JZ2017AKZR0129), the Foundation for Oversea Master Project from the Ministry of Education of the People's Republic of China (Grant No. 2160311028), and the start-up funding from the Hefei University of Technology (Grant No. 407037164).
