国家自然科学基金项目41161012, 41240001;教育部新世纪优秀人才支持计划项目NCET-10-0019;甘肃省高等学校基本科研业务费项目;National Natural Science Foundation of China,No.41161012;No.41161012;The Program for New Century Excellent Talents in University from the Education Ministry of China,No.NCET-10-0019;The Basic Scientific Research Foundation in University of Gansu Province