国家自然科学基金61370083,61073043,61073041,61370086,61402126;国家教育部博士点基金20112304110011,20122304110012资助Supported by National Natural Science Foundation of China61370083,61073043,61073041,61370086,61402126;Na-tional Research Foundation for the Doctoral Program of Higher Education of China20112304110011,20122304110012