1. Institute of Chemistry, Martin Luther University Halle-Wittenberg, Kurt-Mothes Str. 2, Halle 06120, Germany
2. Institute of Mathematics, Martin Luther University Halle-Wittenberg, Theodor-Lieser-Str. 5, Halle 06120, Germany
3. Shaanxi International Research Center for Soft Matter, Xi’an Jiaotong University, Xi’an 710049, P. R. China