1. Physik-Department,
Lehrstuhl für Funktionelle Materialien, Technische Universität München, James-Franck-Str. 1, 85748 Garching, Germany
2. College
of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, P. R. China
3. Deutsches Elektronen-Synchrotron (DESY), Notkestr. 85, 22607 Hamburg, Germany
4. Department
of Fibre and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56-58, SE-100 44 Stockholm, Sweden