基金Supported by the National Research Foundation for the Doctoral Program of Ministry of Education of China under Grant Nos.2005035900620040359004(国家教育部博士点基金)+1 种基金the Shanghai Science Committee Foundation for the Mountaineering Action Plan under Grant No.06DZ15005(上海市科委"登山行动计划"重大项目基金)the Xuzhou Normal University Research Foundation(徐州师范大学项目基金)