国家自然科学基金重大研究计划集成项目No.91215301;北京市属高等学校创新团队建设与教师职业发展计划项目No.IDHT20130512.This work was supported by the Major Research Plan Program of National Natural Science Foundation of China 91215301, and the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges Under Beijing Municipality IDHT20130512.