国家自然科学基金No.31272319;高等学校博士学科点专项科研基金博导类No.20111401110010;山西省特色学科重点项目No.2011-SXDX-SWX-003;Supported by the National Natural Science Foundation of China No.31272319,the Specialized Fund for the Dorctoral Program of Higher Education Ph.D.Superrisor No.20111401110010 and the Special Subject and Key Project of Shanxi ProvinceNo.2011-SXDX-SWX-003