1. School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an 710021, P.R. China
2. State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710000, P.R. China
3. Institute of Nanoscience and Nanotechnology, NCSR “Demokritos”, Agia Paraskevi 15341, Greece