1. Nanotube Research Center (NTRC), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
2. SORST, Japan Science and Technology Agency (JST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
3. Institute for Chemical Research (ICR), Kyoto University, Uji, Kyoto 611-0011, Japan