1. College of Light Industry, Textile & Food Engineering; Sichuan Univ; Chengdu P.O. Box 610065 China
2. Key Laboratory of Leather Chemistry and Engineering; Ministry of Education, Sichuan Univ; Chengdu P.O. Box 610065 China
3. Natl. Engineering Research Center of Solid-State Manufacturing; Luzhou P.O. Box 646000 China