Acknowledgements
This work was founded by the Peacock Science and Technology Innovation Project of Shenzhen (KQJSCX20170328153821275), the National Science Foundation of China (31601230), the Key University Science Research Project of Jiangsu Province (17KJA210002), and Priority Academic Program Development of Jiangsu Higher Education Institutions. We thank Prof. Cunxu Wei and Dr. Juan Wang for the fruitful discussions and valuable suggestions on this study.