Fund: The project was supported by the National Natural
Science Foundation of China (Grant Nos. 11471160; 1110 1114), the National
Statistical Science Research Key Program of China (Grant No. 2013LZ45),
the Fundamental Research Funds for the Central Universities (Grant No.
30920130111015), the Jiangsu Provincial Basic Research Program (Natural
Science Foundation) (Grant No. BK20131345) and sponsored by Qing Lan Project. |