1. AGH University of Science and Technology
2. Faculty of Energy and Fuels
3. 30-059 Krakow
4. Poland
5. University of Science and Technology Beijing
6. School of Materials Science and Engineering
7. Beijing 100083
8. China
9. Beijing Municiple Key Lab for Advanced Energy Materials and Technologies
10. AGH Centre of Energy
11. Department of Physics
12. Northern Illinois University
13. DeKalb
14. USA