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排序方式: 共有425条查询结果,搜索用时 10 毫秒
331.
Tsuyoshi Kariya Ryutaro Minami Tsuyoshi Imai Mao Ota Youichi Endo Shin Kubo Takahashi Shimozuma Hiromi Takahashi Yasuo Yoshimura Satoshi Ito Takahashi Mutoh Keishi Sakamoto Yoshika Mitsunaka 《Journal of Infrared, Millimeter and Terahertz Waves》2011,32(3):295-310
A 28 GHz 1 MW with TE8,3 cavity for GAMMA10 tandem mirror and a 77 GHz 1.5 MW gyrotron with TE18,6 for Large Helical Device (LHD) have been developed to upgrade their Electron Cyclotron Heating (ECH) systems. In the 28 GHz gyrotron, the maximum power of 1.05 MW was obtained, which is in agreement with its design target value. And the high efficiency of 40% without collector potential depression (CPD) was obtained with 0.8 MW. In the first and second 77 GHz gyrotrons, 0.8 MW 3.6 sec., 0.3 MW 60 sec operations have been achieved, but several issues due to the stray RF and velocity dispersion have been found, too. In consideration of these, the design improvement was performed to aim at 1.5 MW in the third tube. In the short pulse test, the maximum output power of 1.6 MW and the maximum total efficiency of 49.4% with CPD were obtained. In the long pulse test, the pulse length extended to 5 sec with 1 MW, 1800 sec with 0.1 MW, 1.6 sec with 1.5 MW. Total injection power of 3.1 MW to LHD plasma has been achieved. It is shown that the electron beam pitch factor ?? decreases with increasing of beam current, comparing with the experimental and calculation results. 相似文献
332.
Monma K Araki R Ichikawa H Sato M Uno N Sato K Tobe T Kuribara H Matsuoka T Hino A Saito K 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2004,45(4):184-190
Genetially modified organisms (GMOs) were explored in food samples obtained from November 2000 to March 2003 in the Tokyo area by using PCR and real-time PCR techniques. The existence of Roundup Ready Soybean (RRS) was surveyed in processed foods derived from soybeans, such as tofu, boiled soybean, kinako, nama-age, abura-age, natto, miso, soymilk and yuba. RRS was detected in 3 of 37 tofu, 2 of 3 nama-age, 2 of 3 yuba and 3 of 3 abura-age samples. The CBH351 in 70 processed corn foods, NewLeaf Plus and NewLeaf Y in 50 processed potato foods, and 55-1 papaya in 16 papayas were surveyed. These GMOs were not detected among the samples. Qualitative and quantitative analyses of RRS and genetically modified (GM) corn were performed in soybean, corn and semi-processed corn products such as corn meal, corn flour and corn grits. RRS was detected in 42 of 178 soybean samples, and the amount of RRS in RRS-positive samples was determined. The content was in the range of 0.1-1.4% in identity-preserved soybeans (non-GMO), and 49.8-78.8% in non-segregated soybeans. On the other hand, GM corns were detected in 8 of 26 samples. The amount of GM corn in GM corn-positive samples was in the range of 0.1-2.0%. 相似文献
333.
Yasuhisa Oya Suguru Masuzaki Masayuki Tokitani Naoaki Yoshida Hideo Watanabe Yuji Yamauchi Tomoaki Hino Mitsutaka Miyamoto Yuji Hatano Kenji Okuno 《Fusion Engineering and Design》2013,88(9-10):1699-1703
The stress relieved tungsten samples were placed at three positions, PI (sputtering erosion dominated area), DP (deposition dominated area) and HL (Higher heat load area) during 15th plasma experiment campaign in Large Helical Device (LHD) at National Institute for Fusion Science (NIFS), Japan and were exposed to ~ 6700 shots of hydrogen plasma in a 15th long-term experiment campaign in LHD. Thereafter, the additional deuterium ion implantation to these tungsten samples was performed to evaluate the change of hydrogen isotope retention capacity in the samples by long-term plasma exposure. It was found that the carbon-dominant mixed-material layer with more than 100 nm thickness was formed on a wide area of the tungsten surface. The thicker mixed-material layer was formed on the DP sample, where the deuterium retention was about 21 times as high as that for pure W. The major desorption temperature of deuterium was shifted toward higher temperature side, which was comparable to the trapping characteristic of carbon or irradiation damages. 相似文献
334.
Xiang Liu Tsuyoshi Yamada Yuji Yamauchi Yuko Hirohata Tomoaki Hino Nobuaki Noda 《Fusion Engineering and Design》2004,70(4):425-334
Helium irradiation experiments of V–4Ti alloy were conducted in an ECR ion irradiation apparatus by using helium ions with energy of 5 keV. The ion fluence was in the range from 1 × 1017 He/cm2 to 8 × 1017 He/cm2. After the helium ion irradiation, the helium retention was examined by using a technique of thermal desorption spectroscopy (TDS). After the irradiation, the blisters with a size of about 0.1 μm were observed at the surface, and the blister density increased with the ion fluence. Two desorption peaks were observed at approximately 500 and 1200 K in the thermal desorption spectrum. When the ion fluence was low, the retained helium desorbed mainly at the higher temperature regime. As increase of the ion fluence, the desorption at the lower temperature peak increased and the retained amount of helium saturated. The saturated amount was approximately 2.5 × 1017 He/cm2. This value was comparable with those of the other plasma facing materials such as graphite. 相似文献
335.
Nobuko Hanada Takayuki Ichikawa Satoshi Hino Hironobu Fujii 《Journal of Alloys and Compounds》2006,420(1-2):46-49
Kinetics of hydrogen absorption and desorption reactions was investigated on the MgH2 composite doped with 1 mol% Nb2O5 as a catalyst by ballmilling. The composite after dehydrogenation at 200 °C absorbed gaseous hydrogen of 4.5 mass% even at room temperature under lower pressure than 1 MPa within 15 s and finally its capacity reached more than 5 mass%. On the other hand, the catalyzed MgH2 after rehydrogenation desorbed 6 mass% hydrogen at 160 °C under purified He flow, which followed the first order reaction. From the Kissinger plot, the activation energy for hydrogen desorption was estimated to be 71 kJ/mol H2, indicating the product was significantly activated due to the catalytic effect of Nb2O5. 相似文献
336.
Ryutaro Koide Emiel J. M. Hensen Jean F. Paul Sylvain Cristol Edmond Payen Hiroyuki Nakamura Rutger A. van Santen 《Topics in Catalysis》2007,45(1-4):175-179
Benzene adsorption on a WS2(100) surface was studied by ab initio periodic DFT computations. Benzene adsorption is facile on the bridge site of the bare W edge via η2 or η3 coordination. Taking into account the stable configuration at the W edge under typical hydrotreating reaction conditions
(623 K, H2S/H2 = 0.01), benzene adsorption is found to be difficult, even when defective bridge sites are created. 相似文献
337.
Abdullah Yassin Takashi Ueda Tatsuaki Furumoto Mohd Sanusi Abdul Aziz Ryutaro Tanaka Akira Hosokawa 《Journal of Mechanical Science and Technology》2010,24(1):77-80
This paper investigates tool wear mechanisms of a ball end mill in cutting laser sintered material. Cutting edge temperature
is measured by using a three-color pyrometer with an optical fiber. Bulk carbon steel JIS S55C is selected as the standard
steel. Experimental results show that tool life in cutting sintered material is shorter than that in cutting JIS S55C. Observations
by SEM show that adhesion of the work material and micro chipping are the main wear mechanisms in cutting sintered material.
The corresponding cutting edge temperature shows a continuous increase as wear evolves with cutting time. 相似文献
338.
Kato Y Sakamoto N Kiriyama R Takenaka T Kurisu Y Nozaki D Sato F Iida T 《The Review of scientific instruments》2012,83(2):02A317
In order to contribute to various applications of plasma and beams based on an electron cyclotron resonance, a new concept on magnetic field with all magnets on plasma production and confinement has been proposed with enhanced efficiency for broad and dense ion beam. The magnetic field configuration consists of a pair of comb-shaped magnet surrounding plasma chamber cylindrically. Resonance zones corresponding for 2.45 GHz and 11-13 GHz frequencies are positioned at spatially different positions. We launch simultaneously multiplex frequencies microwaves operated individually, try to control profiles of the plasma parameters and the extracted ion beams, and to measure them in detail. 相似文献
339.
Noriyuki Yonezawa Tsutomu Namie Tomohide Ikezaki Tetsuo Hino Hiroyuki Nakamura Yoshimi Tokita Ryoichi Katakai 《Reactive and Functional Polymers》1996,30(1-3):261-268
Bisfunctional biphenylene monomers were designed, synthesized, and inspected as building blocks for aromatic polyketone synthesis. Starting from 2,2′-dimethoxybiphenylene (1), a highly activated acyl-acceptant biphenylene monomer affording high molecular weight polyketones, two types of biphenylene monomers were developed: 5,5′-bis(3[4]-chlorobenzoyl)-2,2′-dimethoxybiphenylenes (6) which readily gave the corresponding polyketones by nickel-catalyzed aromatic coupling polymerization and 2,2′-bis(trifluoromethyl)-4,4′-biphenylenedicarboxylic acid (27) which reacted with biphenylene 1 in P2O5---CH3SO3H to give the corresponding fluorinated aromatic polyketone, selectively. The related model reactions for both monomer synthesis and polymerization were also investigated. 相似文献
340.
Machinability of BN free-machining steel in turning 总被引:1,自引:0,他引:1
Ryutaro Tanaka Yasuo Yamane Katsuhiko Sekiya Norihiko Narutaki Tetsuo Shiraga 《International Journal of Machine Tools and Manufacture》2007,47(12-13):1971-1977
In the past few years, extensive researches have been done to improve the machinability of work materials in order to increase productivity and reduce the effect on the environment. To satisfy these demands, various free-machining steels have been researched and developed. One of them is BN free-machining steel that contains hexagonal boron nitride (h-BN). However, the machinability was not stable. In this study, machining tests were carried out to clarify the machinability of steels and appropriate chemical composition of work material and tool material to achieve high efficient machining. Tested work materials were plane carbon steel JIS S45C and BN free-machining steels. The JIS S45C was used as the standard. The tool wear in turning BN free-machining steel was smaller than that in turning standard steel. In case of turning BN1 with P30 at 200, 300 m/min, the wear progress rate of flank wear and crater depth were about half as much as that in turning standard steel. BN free-machining steel showed slightly lower cutting temperature and smaller cutting force in comparison with standard steel at the tested cutting speeds. Al and N were detected as a layer at the tool wear region of P grade carbide tools after turning BN free-machining steel at high cutting speed. It is thought that one of the main reasons of outstanding machinability of BN free-machining steel is that the deposited layer containing Al and N acts as diffusion barrier at the tool–chip interface. In turning larger Al content BN-added steel with higher Ti content cutting tools, a larger wear reduction was observed. Therefore, it is said that not only added BN but also appropriate Al is necessary in work material. 相似文献