[1] Nanjing Univ Sci & Technol, Sch Mat Sci & Engn, Nanjing, Peoples R China
[2] Nanjing Univ Sci & Technol, Herbert Gleiter Inst Nanosci, Nanjing, Peoples R China
[3] Tsinghua Univ, Sch Mat Sci & Engn, Beijing 100084, Peoples R China
[4] Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China