1. School
of Materials Science and Engineering, Shaanxi Normal University, Chang’an
District, Xi’an 710119, China
2. School
of Physics and Information Technology, Shaanxi Normal University, Chang’an
District, Xi’an 710119, China
3. Basic
Experimental Teaching Center, Shaanxi Normal University, Yanta
District, Xi’an 710062, China
4. School
of Chemistry and Chemical Engineering, Shaanxi Normal University, Chang’an
District, Xi’an 710119, China