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排序方式: 共有124条查询结果,搜索用时 312 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.
6.
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
7.
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
8.
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
9.
In this paper we present a new acoustic-resonance microscopy, Electromagnetic-Resonance-Ultrasound Microscopy (ERUM), to measure the localized elastic stiffness of a solid material. It visualizes the resonance-frequency shift of vibrating piezoelectric crystal (langasite, La3Ga5SiO14) excited by an electric field from a solenoid coil. The acoustic coupling is made only at the tip of the crystal touching the specimen surface. Being based on the calibration for the specimen's effective stiffness, the local elasticity is determined from the resonance frequencies of the crystal with the Rayleigh-Ritz method. An approximate model for the specimen's effective stiffness predicts the shift of resonance frequencies, for which the conventional Hertz-contact model is improved. As an illustrating example, the mapping of Young's modulus of a duplex stainless steel is presented, which shows good agreement with the existing study. 相似文献
10.
Hirotsugu Minami Wanhong Cai Tatsuya Kusumoto Kaiji Nishikawa Qiangbin Zhang Sadanobu Inoue Ikuo Atsuya 《Analytical sciences》2003,19(10):1359-1363
Isotope dilution analysis of the sub-microg l(-1) levels of selenite and selenate in natural water samples by microwave-induced nitrogen plasma mass spectrometry (MIP-MS) was performed. An appropriate amount of a spike solution containing 78Se-selenite and 78Se-selenate was added to the natural water sample to be analyzed. Both analytes in the water were then concentrated simultaneously by passing the sample through a column that was filled with an anionic exchange resin. After the concentration process, all of the selenite and some of the selenate on the resin were eluted by 0.03 M nitric acid. The residual selenate was eluted by 0.13 M nitric acid. The eluted sample solutions were injected into MIP-MS, and isotope dilution analyses were carried out. Selenite and selenate concentrations as low as 0.01 microg l(-1) in the natural water sample were successfully determined by the proposed method. 相似文献