1. Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg
7, D-55099 Mainz, Germany
2. Department of Physics, American University of Beirut, P.O. Box 11-0236, Beirut 1107 2020, Lebanon
3. Chemical-Pharmaceutical Academy, Professora Popova 14, 197022 St. Petersburg, Russia
4. Institute of Macromolecular
Compounds, Russian Academy of Sciences, 31 Bolshoy pr., 199004 St. Petersburg, Russia
5. Institut
für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg
7, D-55099 Mainz, Germany