Beijing Key Laboratory of Advanced Functional Polymer Composites College of Materials Science and Engineering Beijing University of Chemical Technology Beijing 100029 China;
Center for Nanofibers and Nanotechnology National University of Singapore Singapore 1157 Singapore;
Institute of Plant Protection Chinese Academy of Agricultural Sciences Beijing 100193 China;
Beijing Key Laboratory of Advanced Functional Polymer Composites College of Materials Science and Engineering Beijing University of Chemical Technology Beijing 100029 China;