1. School of Physical Science and Technology, Guangxi Key Lab of Processing for Nonferrous Metals and Featured Materials and Key lab of new Processing Technology for Nonferrous Metals and Materials, Ministry of Education, School of Resources, Environmental and Materials, Guangxi University, Nanning 530004, China
2. School of Physics and Electronics, Hunan University, Changsha 410082, China
3. School of Physics and Electronic Engineering, Hubei University of Arts and Science, Xiangyang 441053, China