1. Research Center for Structural Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Japan 305-0047
2. Research Center for Electronic and Optical Materials, National Institute for Materials Science, Tsukuba, Japan 305-0044
3. Department of Aerospace Engineering, Tohoku University, Sendai, Japan 980-8579
4. Center for Advanced Materials, Forestry and Forest Products Research Institute, Tsukuba, Japan 305-8687