| Affiliation: | Department of Applied Physics, Lanzhou University of Technology, Lanzhou 730050, China;School of Material Science and Engineering, Lanzhou University of Technology, Lanzhou 730050,China;Department of Applied Physics, Lanzhou University of Technology, Lanzhou 730050, China;School of Material Science and Engineering, Lanzhou University of Technology, Lanzhou 730050,China;School of Material Science and Engineering, Lanzhou University of Technology, Lanzhou 730050,China;College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070,China |
