1. State Key Laboratory of Urban Water Resource and Environment School of Chemistry and Chemical Engineering Harbin Institute of Technology Harbin 150001 P. R. China
2. iNANO and Department of Physics and Astronomy Aarhus University Aarhus 8000 Denmark
3. Condensed Matter Science and Technology Institute School of Instrumentation Science and Engineering Harbin Institute of Technology Harbin 150001 P. R. China
4. Department of Medical Imaging The Fourth Affiliated Hospital of the Harbin Medical University Harbin 150001 P. R. China