1. School of Electrical Engineering and Automation, Hefei University of Technology 1 , Hefei 230009, People's Republic of China
2. Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology 2 , 50-370 Wrocław, Poland
3. School of Chemistry and Chemical Engineering, Hefei University of Technology 3 , Hefei 230009, People's Republic of China