1. CPFRR, School of Light Industry and Food, ERCPSP, South China University of Technology, Guangzhou, P.R. China.
2. School of Materials Science and Engineering, South China University of Technology, Guangzhou, P.R. China.
3. Commonwealth Scientific and Industrial Research Organisation, CMSE, Melbourne, Vic 3169, Australia.
4. Corresponding author. Phone: +61 3 9545 2777. Fax: +61-3-95441128. E-mail: long.yu@csiro.au