1. College of Textile Science and Engineering, International Institute of Silk, Zhejiang Sci-Tech University, Hangzhou 310018, China
2. Dept of Physics, University of Milano-Bicocca, P.zza della Scienza 3, Milano I-20126, Italy
3. CNR-STIIMA, Italian National Research Council, Institute of Intelligent Industrial Technologies and Systems for Advanced Manufacturing, 13900 Biella, Italy