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排序方式: 共有138条查询结果,搜索用时 15 毫秒
1.
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
2.
Matsunaga S Kobayashi H van Soest RW Fusetani N 《The Journal of organic chemistry》2005,70(5):1893-1896
Three new bromotyrosine derivatives, 11-N-methylmoloka'iamine (1), 11-N-cyano-11-N-methylmoloka'iamine (2), and kuchinoenamine (3), were isolated as antibacterial constituents from a marine sponge Hexadella sp. Their structures were elucidated on the basis of spectral and chemical methods. They exhibited moderate antibacterial activity against the fish pathogenic bacterium Aeromonas hydrophila. 相似文献
3.
Yoshio Takizawa Hirotsugu Aiga Masayoshi Watanabe Isao Shinohara 《Journal of polymer science. Part A, Polymer chemistry》1983,21(11):3145-3153
Ionene polymers characterized by the alternating structure of ionene and crystalline poly(ethylene oxide) (PEO) segments were prepared as a function of PEO segment size. A microstructure of these ionenes and their 7,7,8,8-tetracyanoquinodimethane (TCNQ) salts were investigated with x-ray diffraction patterns, thermal scanning behavior, and polarizing micrographs. On the basis of this microstructure, the change in resistivity with temperature was studied. In Arrhenius' plots of the resistivity the simple salts in which the spherulites consisting of the PEO segments were observed showed a sharp decrease in resistivity with a rise in temperature [critical temperature resistor (CTR)] at about the melting point of the PEO segments, whereas the other simple salts in which the spherulites were not observed showed linear temperature dependence. The switching properties were confirmed similarly in repetitive heating/cooling cycles. This CTR characteristic was attributed to an increase in continuity in the conduction paths by melting spherulites. The apparent switching properties were not observed in the complex salts. 相似文献
4.
The objective of this study was to examine some fundamental factors involved in the design and construction of the anode magnetron dc glow discharge processes as well as its performance in plasma cleaning and polymerization. Those advantages of anode magnetron include the capability of the magnetron to operate at low pressure, as well as decreasing the thickness of cathode dark space, i.e., the negative glow which contains a higher concentration of ions and active species was more closely to the cathode surface, which makes the plasma surface cleaning and polymerization an effective and uniform processes. The deposition rate at a given discharge power is increased by the presence of anode magnetrons, and is also much higher relative to rf and af. The refractive index of dc plasma film at a given polymer thickness (such as TMS, 70 nm, RI: 2.4) is higher than rf, af, and cascade arc plasma (RI: 1.6–1.7). 相似文献
5.
A novel technique for surface-induced orientation of liquid crystal (LC) molecules is proposed, using a polyimide surface exposed to a unidirectional water flow. The LC molecules director was unidirectionally oriented along the water flow direction on the polyimide surface. The orientational state of the LC director was strongly dependent upon whether the water flow exposure was carried out before or after thermal curing for imidization, and also upon the temperature of water flow. 相似文献
6.
A (photo-polymerizable liquid crystal (LC) monomer/LCs/chiral dopant/photoinitiator) mixture with a smectic A (SmA)-chiral nematic (N*) phase transition was sandwiched between two ITO glass substrates which were not subjected to any surface orientation treatment. When an electric field-induced homeotropically oriented SmA phase of the mixture was irradiated with UV light, an oriented liquid crystalline polymer (LCP) network was formed upon photo-polymerization of the LC monomer. Then, a (homeotropically oriented LCP network/LCs/chiral dopant) composite with a SmA-N* phase transition was prepared. A focal-conic texture appeared in the heat-induced N* phase of the composite upon heating from the transparent state of the homeotropically oriented SmA phase; the focal-conic texture exhibited strong light scattering. Upon cooling the composite to the SmA phase, this phase was again homeotropically oriented due to the strong intermolecular interaction between the LC molecules and the homeotropically oriented LCP network. Thus, the transparent state of the SmA phase and the light scattering state of the N* phase occurred reversibly upon cooling and heating, accompanied by the thermal SmA-N* phase transition. 相似文献
7.
Mikiyasu Shirai Matthew Beard James T. Pearson Takashi Sonobe Hirotsugu Tsuchimochi Yutaka Fujii Emily Gray Keiji Umetani Daryl O. Schwenke 《Journal of synchrotron radiation》2013,20(3):441-448
Synchrotron radiation microangiography is a powerful tool for assessing adverse changes in pulmonary vessel density associated with primary pulmonary hypertension (PH). Congestive heart failure (CHF) leads to a `secondary' onset of PH, yet it is unknown whether secondary PH is also associated with reduced vessel density. This study utilized synchrotron radiation to assess both pulmonary vessel density and endothelial function in a Dahl rat model of CHF with secondary PH. High salt‐fed Dahl salt‐sensitive (Dahl‐S) and salt‐resistant (Dahl‐R) rats were anesthetized and microangiography was performed to assess the pulmonary vessel density and vascular responses to (i) sodium nitroprusside (5.0 µg kg?1 min?1), (ii) acetylcholine (3.0 µg kg?1 min?1) and (iii) ET‐1A receptor blockade, BQ‐123 (1 mg kg?1). Dahl‐S rats developed CHF and secondary PH as evident by endothelial dysfunction, impaired vasodilatory responses to acetylcholine, enhanced vasodilatory responses to BQ‐123 and extensive pulmonary vascular remodeling. Consequently, the pulmonary vessel density was adversely reduced. Interestingly, the etiology of secondary PH manifests with structural and functional changes that are comparable with that previously reported for primary PH. One important discrepancy, however, is that ET‐1 modulation of pulmonary vessels is most striking in vessels with a diameter range of 100–200 µm in secondary PH, in contrast to a range of 200–300 µm in primary PH. Such discrepancies should be considered in future studies investigating primary and secondary forms of PH. 相似文献
8.
Recently, we have developed novel Eu(III) complexes with three beta-diketonates and one asymmetric bis(phosphine) oxide whose light emission intensity is drastically increased. In this paper, one of these complexes is investigated by the density functional theory calculation. Sixteen isomers of this complex have been considered. The ratio of the existence for the most stable isomer (B1_1a) is found to be about 51%, and the sum of the ratio of the existence for the six most stable isomers (B1_1a, B1_3a, B1_8a, B1_2a, B1_1b, and B1_5a) is about 100%, assuming the Boltzmann distribution (T = 300 K). The coordination structures of the six most stable isomers in the ground states are similar, and we can expect asymmetric ligand fields for them, favorable for the efficient light emission. Vertical excitation energies and oscillator strengths for each isomer have been obtained by the time-dependent density functional theory. With the red-shift of the wavelength and the interpolation by Gaussian convolution, both the calculated absorption spectra for the most stable isomer B1_1a and the calculated absorption spectra for the ensemble average of the isomers are found to be similar to the experimental fluorescence excitation spectra. The efficiency of energy transfer from the triplet excited state to the Eu(III) ion is considered by calculating DeltaEET (difference between the adiabatic excitation energy of the complex for the lowest triplet state and the emission energy of the Eu(III) ion for 5D0 to 7F2). The characters for the lowest triplet states for the isomers are investigated by the spin density distributions of the triplet states. 相似文献
9.
ABSTRACT Coupling of the sodium salt of S-(methyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-α-galacto-2-nonulopyranosylonate)-(2→'6)-2,3,4-tri-O-acetyl-1,6-dithio-β-D-glucopyranose (5), -β-D-galactopyranose (8), or S-(methyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-α-D-galacto-2-nonulopyranosylonate)-(2→'6)-O-(2,3,4-tri-O-acetyl-6-thio-β-D-galactopyranosyl)-(1→'4)-2,3,6-tri-O-acetyl-1-thio-β-D-glucopyranose (12), which were prepared from the corresponding 1-hydroxy compounds, 1, 2, and 9, via 1-chlorination, displacement with thioacetyl group, and S-deacetylation, with (2S,3R,4E)-2-azido-3-O-benzoyl-1-O-(p-toluenesulfonyl)-4-octadecene-1,3-diol (13), gave the corresponding β-thioglycosides 14, 18 and 22, respectively in good yields. The β-thioglycosides obtained were converted, via selective reduction of the azide group, condensation with octadecanoic acid, and removal of the protecting groups, into the title compounds. 相似文献
10.