1. Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, 52428 Jülich, Germany
2. Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
3. Department of Physics and Materials Science, City University of Hong Kong, Kowloon, Hong Kong
4. Biology and Soft-Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA