1. Department
of Trace Examination, National Police University of China, Shenyang 110035, P. R. China
2. Key
Laboratory of Impression Evidence Examination and Identification Technology, Ministry of Public Security, Shenyang 110035, P. R. China
3. State
Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, P. R. China
4. Department of Chemistry & Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma 73019, United States