1. Institute for Clean Energy and Advanced Materials, School of Materials and Energy, Southwest University, Chongqing 400715, P. R. China
2. State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, P. R. China
3. Chongqing Engineering and Technology Research Center for Novel Silk Materials, Southwest University, Chongqing 400715, P. R. China