国家自然科学基金No.51379715;陕西省重点科技创新团队计划No.2014KCT-27;高等学校博士学科点专项科研基金No.20136101110001;陕西省教育厅基金No.12JK0654 Supported by the National Natural Science Foundation of China No.51379715,the Program for Key Science and Technology Innovation Team in Shaanxi ProvinceNo.2014KCT-27,the Specialized Research Fund for the Doctoral Program of Higher EducationNo.20136101110001 and Shaanxi Provincial Education Department of FundNo.12JK0654