国家自然科学基金41101098,41371113 [National Natural Science Foundation of China 41101098,41371113];国家社会科学基金13CGL092 [National Social Science Foundation of China13CGL092];华中农业大学人文社会学科优秀青年人才项目[the Outstanding Youth Foundation Project for Humanities and Social Science in Huazhong Agricultural University]