国家自然科学基金61170321,61271238,61475075;高等学校博士学科点专项科研基金批准号:20110092110024,20123223110003资助的课题.* Project supported by the National Natural Science Foundation of ChinaGrant .61170321,61271238,61475075;the Specialized Research Fund for the Doctoral Program of Higher Education of ChinaGrant .20110092110024,20123223110003