1. Soft material physics group, Faculty of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higasshi Hiroshima 739-8521, Japan, Department of Polymer Science and Engineering, Yamagata University, 4-3-16, Yonezawa 992-8510, Japan, and Kawasaki Development Center, R&D Department, SunAllomer Ltd. 3-2 Yako 2-chome, Kawasaki-ku, Kawasaki, 210-8548, Japan