This work is partially supported by the Natural Science Foundation of China (11401185, 61403056), Scientific Research Fund of Hunan Provincial Education Department (13B004), Hunan Provincial Natural Science Foundation of China (14JJ6039) and the Science and Technology Plan Project of Hunan Province (2016TP1020). The author (Qiao) also thanks the UTRGV President't Endowed Professorship and the UTRGV College of Science seed grant for their partial supports.
This work is partially supported by the Natural Science Foundation of China ( 11401185 , 61403056 ), Scientific Research Fund of Hunan Provincial Education Department (13B004), Hunan Provincial Natural Science Foundation of China ( 14JJ6039 ) and the Science and Technology Plan Project of Hunan Province (2016TP1020). The author (Qiao) also thanks the UTRGV President’t Endowed Professorship and the UTRGV College of Science seed grant for their partial supports.