1. Technology Research and Development Department, General Technology Division, Central Japan Railway, 1545-33 Ohyama, Komaki City, Aichi 485-0801, Japan
2. Fuel Cell Nanomaterials Center, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, Japan
3. Tokyo University of Science, 1-3 Kagurazaka, Shinjyuku-ku, Tokyo 162-8601, Japan