1. Saint Petersburg State University, 7/9 Universitetskaya Nab., St. Petersburg 199034, Russian Federation
2. International Tomography Center SD RAS, Institutskaya Str. 3a, Novosibirsk 630090, Russian Federation
3. Institute of Macromolecular Compounds, Russian Academy of Sciences, Bolshoii Pr., 31, 199004 St. Petersburg, Russian Federation