国家自然科学基金40902020,51002042;高等学校博士学科点专项科研新教师基金120090111120019;中央高校基本科研业务费专项资金2011HGQL1003;the National Natural Science Foundation of China40902020,51002042;the Special Research Foundation of Doctor Program20090111120019;the Fundamental Research Funds for the Central Universities2011HGQL1003