Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Sekine, Yurina; Takagi, Hajime*; Sudo, Sayoko*; Kajiwara, Yutaro*; Fukazawa, Hiroshi; Fukazawa, Tomoko*
Polymer, 55(24), p.6320 - 6324, 2014/11
Times Cited Count：26 Percentile：67.65(Polymer Science)To investigate the effects of structure of polymer side chains on structure of water in hydrogels, Raman spectra of polyacrylamide (PAA) and poly-
,-dimethylacrylamide (PDMAA) hydrogels were measured. PAA and PDMAA have similar chemical structures, except for the side chain structure. The result shows that the frequency of the OH stretching mode for the PAA hydrogel decreases as the water content decreases, while that for the PDMAA hydrogel increases. We conclude that most of the bound water molecules in the PAA hydrogel form four strong hydrogen bonds with the hydrophilic groups in the side chain of PAA, whereas those in the PDMAA hydrogel form weak hydrogen bonds with surrounding water molecules. The water structure is an important factor governing the physical and chemical properties of gel materials.
Sakamoto, Keishi; Kasugai, Atsushi; Takahashi, Koji; Minami, Ryutaro*; Kobayashi, Noriyuki; Kajiwara, Ken
Nature Physics, 3(6), p.411 - 414, 2007/06
Times Cited Count：193 Percentile：97.29(Physics, Multidisciplinary)The first 1 MW quasi-continuous wave generation is demonstrated at 170 GHz gyrotron of TE31,8 resonator mode with outstanding efficiency of greater than 55 percent. The robust high efficiency oscillation is obtained in a hard self-excitation region with an active control of gyrotron parameters. Furthermore, a novel nonlinear process is found that the desired TE31,8 mode is excited as a parasitic mode of an adjacent TE30,8 mode and finally the TE31,8 dominates a system. This effect extends a substantial soft self-excitation region of the desired mode significantly.
Kasugai, Atsushi; Sakamoto, Keishi; Takahashi, Koji; Kajiwara, Ken; Ikeda, Yukiharu; Komori, Shinji; Kobayashi, Noriyuki; Kariya, Tsuyoshi*; Minami, Ryutaro*; Mitsunaka, Yoshika*
no journal, ,
no abstracts in English
Sekine, Yurina; Fukazawa, Tomoko*; Kajiwara, Yutaro*; Ito, Yu*; Fukazawa, Hiroshi
no journal, ,
no abstracts in English
Sakamoto, Keishi; Kariya, Tsuyoshi*; Oda, Yasuhisa; Minami, Ryutaro*; Ikeda, Ryosuke; Kajiwara, Ken; Kobayashi, Takayuki; Takahashi, Koji; Moriyama, Shinichi; Imai, Tsuyoshi*
no journal, ,
Sakamoto, Keishi; Kariya, Tsuyoshi*; Oda, Yasuhisa; Minami, Ryutaro*; Ikeda, Ryosuke; Kajiwara, Ken; Kobayashi, Takayuki; Takahashi, Koji; Moriyama, Shinichi; Imai, Tsuyoshi*
no journal, ,
