1. School
of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
2. Nano
Interface Center for Energy (NICE), School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
3. School
of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
4. State
Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
5. Beida Information Research, Tianjin 300457, P. R. China