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排序方式: 共有356条查询结果,搜索用时 15 毫秒
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Kazuhiro Watanabe Noboru Akino Tetsuo Aoyagi Noboru Ebisawa Yukio Fujiwara Atsusi Honda Takashi Inoue Takao Itoh Mikito Kawai Minoru Kazawa Junichi Koizumi Masaaki Kuriyama Kenji Miyamoto Naoki Miyamoto Kazuhiko Mogaki Yoshihiro Ohara Tokumichi Ohga Yoshikazu Okumura Hiroshi Oohara Katsumi Ohshima Fujio Satoh Kazuhiko Shimizu Syunji Takahashi Hirotsugu Usami Katsutomi Usui Masahiro Yamamoto Takeshi Yamazaki 《Radiation Physics and Chemistry》1997,49(6):631-639
A negative-ion-based neutral beam injector (N-NBI) has been constructed for JT-60U. The N-NBI is designed to inject 500 keV, 10 MW neutral beams using two ion sources, each producing a 500 keV, 22 A D− ion beam. In the preliminary experiment using one ion source, a D− ion beam of 13.5 A has been successfully accelerated with an energy of 400 keV (5.4 MW) for 0.12 s at an operating pressure of 0.22 Pa. This is the highest D− beam current and power in the world. Co-extracted electron current was effectively suppressed to the ratio of Ie/ID− < 1. The highest energy beam of 460 keV, 2.4 A, 0.44 s has also been obtained. To realize 1 MeV class NBI system for ITER (International Thermonuclear Experimental Reactor), demonstration of ampere class negative ion beam acceleration up to 1 MeV is an important mile stone. To achieve the mile stone, a prototype accelerator and a 1 MV, 1 A test facility called MeV Test Facility (MTF) were constructed. Up to now, an H− ion beam was accelerated up to the energy of 805 keV with an acceleration drain current of 150 mA for 1 s in a five stage electrostatic multi-aperture accelerator. 相似文献
3.
An enantioselective total synthesis of (-)-lepadin B has been developed starting from (2S,4S)-2,4-O-benzylidene-2, 4-dihydroxybutanal. The key steps in the synthesis include the use of an aqueous intramolecular acylnitroso Diels-Alder reaction to afford the trans-1,2-oxazinolactam and Suzuki cross-coupling reaction to elaborate the (E,E)-octadienyl unit. 相似文献
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An epoxy-group-containing polymer chain was grafted onto the hollow-fiber form of a porous polyethylene membrane by the immersion of the electron beam-irradiated trunk polymer in glycidyl methacrylate diluted with methanol and 1-butanol. The epoxy group density ranged from 8.5 to 13.4 mol per kg of the trunk polymer. Subsequently, the epoxy groups produced were converted into sulfonic acid and diethylamino groups. The density of -SOH and -N(C2H5), groups was 0.40 and 2.2 mol per kg of the product. respectively. The polymer brush, defined as a polymer chain extending from the surface of a pore toward the interior of the pore, was evaluated from the determination of an equilibrium binding capacity of hen egg lysozyme (HEL) and bovine serum albumin (BSA). The polymer brush prepared in 1-butanol was found to be longer than that prepared in methanol from the determinations of liquid permeability and protein adsorptivity. The proteins were bound to the polymer brush prepared in 1-butanol, followed by the functionalization, at higher degrees of multilayer binding: about 30 for HEL and 6 for BSA. 相似文献
6.
Poly(ethylene oxide-)-poly(1, 1-dimethyl-2, 2-dihexyldisilene) block copolymers (PEO-b-PMHS) were synthesized by the anionic polymerization of masked disilenes initiated with the potassium alkoxide of poly(ethylene glycol). The block copolymer self-assembled into polymer micelles in water accompanied by a transition in the polysilane conformation. 相似文献
7.
The most widely used method for qualitative and quantitative analysis of carbonyl compounds is the 2,4-dinitrophenylhydrazine method through the formation of 2,4-dinitrophenylhydrazone derivatives. However, this method may cause an analytical error because 2,4-dinitrophenylhydrazones have both E- and Z-stereoisomers. Purified aldehyde-2,4-dinitrophenylhydrazone demonstrated only the E-isomer. However under UV irradiation and the addition of acid, both E- and Z-isomers were seen. The spectral patterns of Z-isomers were different from those of E-isomers and the absorption maximum wavelengths were shifted towards shorter wavelengths by 5-8 nm. An equilibrium Z/E isomer ratio was observed in 0.02-0.2% (v/v) phosphoric acid solutions. In the case of acetaldehyde- and propanal-2,4-dinitrophenylhydrazones, the equilibrium Z/E isomer ratios were 0.32 and 0.14, respectively. However, when irradiated with ultraviolet light at 364 nm, the isomer ratios were increased beyond this constant ratio and reached 0.55 and 0.33, respectively. Zero-order rates for decreases of aldehyde derivatives were observed under UV irradiation (364 nm), however the decreases of concentration were not observed in phosphoric acid solutions. The best method for the determination of aldehyde-2,4-dinitrophenylhydrazones by HPLC is to add phosphoric acid to both the sample and the standard solution, to form a 0.02-1% acid solution. 相似文献
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Maki Sachiko Eiji Nishibori Shinobu Aoyagi Makoto Sakata Masaki Takata Mio Kondo Masaki Murata Ryota Sakamoto Hiroshi Nishihara 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(7):696-703
The title compound, [Fe2(C5H5)2(C40H22O2)] or 1,4‐(FcPh)2Aq [where FcPh is 2‐(4‐ferrocenylphenyl)ethynyl and Aq is anthraquinone], was synthesized in an attempt to obtain a new solvent‐incorporating porous material with a large void space. Thermodynamic data for 1,4‐(FcPh)2Aq show a phase transition at approximately 430 K. The crystal structure of solvent‐free 1,4‐(FcPh)2Aq was determined at temperatures of 90, 300 and 500 K using synchrotron powder diffraction data. A direct‐space method using a genetic algorithm was employed for structure solution. Charge densities calculated from observed structure factors by the maximum entropy method were employed for model improvement. The final models were obtained through multistage Rietveld refinements. In both phases, the structures of which differ only subtly, the planar Aq fragments are stacked alternately in opposite orientations, forming a one‐dimensional column. The FcPh arms lie between the stacks and fill the remaining space, leaving no voids. C—H...π interactions between the Ph and Fc fragments mediate crystal packing and stabilization. 相似文献
10.
Mina Sakuragi Naoto Aoyagi Yoshio Furusho Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2014,52(14):2025-2031
In this study, we investigated the CO2‐capture/release behavior of the polystyrene‐bearing cyclic amidine pendant groups, which was synthesized via free radical polymerization of HCl salt of the corresponding styrene monomer followed by neutralization. For comparison, we also prepared the polystyrene bearing N‐formyl‐1,3‐propanediamine pendant groups through the hydrolysis of the cyclic amidine group by treatment with an alkaline solution. First, we examined the CO2‐capture/release behaviors of the amidine and amine monomers in aqueous solution in terms of conductivity. The conductivity of a wet DMSO solution of the amidine monomer increased upon CO2 bubbling at 25 °C and reached a stationary value of about 11 mS/m, which indicated the formation of the bicarbonate salt. Conversely, the conductivity decreased to its original value upon N2 bubbling at 50 °C, reflecting the complete release of the trapped CO2 molecules. Both solutions showed the changes in the conductivity with quick responses, and no appreciable difference was observed between them. We then investigated the CO2‐capture/release behaviors of the amidine and amine polymers, by taking advantage of the binary system with polyethylene glycol, and found that the binary system with the amidine polymer captured and released CO2 more efficiently than that with the amine polymer. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2025–2031 相似文献