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1.
Several types of reinforced Nb3Sn wires have been developed to prevent reduction of superconducting properties by applying a strong electromagnetic force. To fabricate a cryocooled magnet using those reinforced wires, we experimentally measured the minimum quench energy (MQE) under cryocooled conditions of some reinforced Nb3Sn wires. As a result, it became clear that thermal stability expressed as MQE was controlled by the temperature margin between the temperature of the operating condition and the transition temperature from superconductivity to normal. Using the FEM analysis, it was realized that the cause of the decline in thermal stability for the reinforced wires was the low thermal conductivity of the reinforced materials. 相似文献
2.
Keishi Sakamoto Atsushi Kasugai Masaki Tsuneoka Koji Takahashi Yukiharu Ikeda Tsuyoshi Imai Takashi Nagashima Mitsuru Ohta Tsuyoshi Kariya Kenichi Hayashi Yoshika Mitsunaka Yosuke Hirata Yasuyuki Itoh Yukio Okazaki 《Journal of Infrared, Millimeter and Terahertz Waves》1997,18(9):1637-1654
A development of 170GHz/500kW level gyrotron was carried out as R&D work of ITER. The oscillation mode is TE31,8. In a short pulse experiment, the maximum power of 750kW was achieved at 85kV/40A. The efficiency was 22%. In the depressed collector operation, 500kW/36%/50ms was obtained. The maximum efficiency of 40% was obtained at PRF=470kW whereas the power decrease by the electron trapping was observed. Pulse extension was done up to 10s at PRF=170kW with the depressed collector operation. The power was limited by the temperature increase of the output window. 相似文献
3.
Degradation of analog device parameters such as drain conductance, gd, due to hot carrier injection has been modeled for NMOSFET's. In this modeling, mobility reduction caused by interface state generation by hot carrier injection and the gradual channel approximation were employed. It has been found that gd degradation can be calculated from linear region transconductance, gm, degradation which is usually monitored for hot carrier degradation of MOSFET's. The values of gd degradation calculated from gm degradation fit well to the measured values of gd degradation The dependence of the gd degradation lifetime on Leff has been also studied, this model also provides an explanation of the dependence on Leff. The model is then useful for lifetime predictions of analog circuits in which gd degradation is usually more important than gm degradation 相似文献
4.
5.
Tsuyoshi Takahashi Masahito Kitou Michio Asai Mitsuyasu Kido Tomio Chiba Junzou Kawakami Yoshiaki Matsui 《Electrical Engineering in Japan》1994,114(2):18-33
Power system control equipment needs higher sensitivity and operational reliability. Advanced voltage control equipment is needed for reducing the frequency of tap changes and improving the characteristics (the relationship between the actual voltage and reference voltage) of the voltage to meet today's power system requirements. However, these objectives are in a trade-off relationship. Studies of voltage control derived from a knowledge base suitable for electric power systems can satisfy these objectives using fuzzy inference. Compared with corresponding conventional equipment, the new equipment improved the deviation of 30 min average voltage of 30 percent. This paper describes the design concept of new voltage control equipment using fuzzy inference. In addition, field test results are described along with rules of fuzzy inference, membership functions, and the deviation of 30 min average voltage through detailed simulation. 相似文献
6.
T. Shimada M. Mizuno K. Kurachi N. Kato O. Sakurada M. Hashiba Y. Nurishi 《Journal of Materials Science》1996,31(14):3691-3695
Low thermal expansion coefficient and high mechanical strength have been attained simultaneously in a composite with microstructures in which the low thermal expansion grains are surrounded by a continuous texture of the grains with high strength. Alloying eucryptite with yttria-stabilized PSZ (partially stabilized zirconia) simultaneously achieved the low thermal expansion coefficient, 1.45 × 10–6, and the high bending strength, 220 MPa, by adjusting the composition and controlling the microstructures by changing the starting powders and the milling durations. Grain size and reactions between the coupled materials determined the critical processing conditions. 相似文献
7.
UV-Vis spectroscopy was used to directly determine the concentration of Eu(Ⅱ) during electroreduction of Eu(Ⅲ) in hydrochloric acid medium. Electroreduction was carried out in a flow type electrolyzer with glassy carbon cathode at the constant potential of -800 mV vs. Ag/AgCl. The effects of oxygen and concentration of hydrochloric acid on the system were investigated. For 0.01 mol·L-1 hydrochloric acid, calibration curves for Eu(Ⅱ) absorption bands at 248 and 320 nm were constructed. Molar absorption coefficients were estimated to be 2016 and 648 L·mol-1·cm-1, respectively. The absorbance strongly decreased with decrease in pH of the solution, whereas concentration of chloride had only a negligible effect. 相似文献
8.
Shionyu-Mitsuyama Clara; Shirai Tsuyoshi; Ishida Hirokazu; Yamane Takashi 《Protein engineering, design & selection : PEDS》2003,16(7):467-478
A computer program system was developed to predict carbohydrate-bindingsites on three-dimensional (3D) protein structures. The programssearch for binding sites by referring to the empirical rulesderived from the known 3D structures of carbohydrateproteincomplexes. A total of 80 non-redundant carbohydrateproteincomplex structures were selected from the Protein Data Bankfor the empirical rule construction. The performance of theprediction system was tested on 50 known complex structuresto determine whether the system could detect the known bindingsites. The known monosaccharide-binding sites were detectedamong the best three predictions in 59% of the cases, whichcovered 69% of the polysaccharide-binding sites in the targetproteins, when the performance was evaluated by the overlapbetween residue patches of predicted and known binding sites. Received April 24, 2003; revised June 2, 2003; accepted June 10, 2003. 相似文献
9.
Y Mizukami T Nagashima K Ikuta E Chikamatsu K Kurachi H Kanemoto T Yagi S Ohhira Y Nimura 《Canadian Metallurgical Quarterly》1998,45(23):1462-1467
Gallbladder carcinoid is a rare disease. In previous reports, classical carcinoid, an entity with a good prognosis, has not been distinguished from endocrine cell carcinoma, a tumor associated with marked cell atypia and mitosis, and a poor prognosis. The patient was a 66 year old woman who presented to our hospital with a chief complaint of jaundice. Pre-operatively, she was diagnosed as having advanced gallbladder carcinoma invading the liver and the hepatic hilus. The patient underwent right hepatic trisegmentectomy with en bloc resection of the caudate lobe and extrahepatic bile ducts, extended lymph node clearance and left hepaticojejunostomy. Histopathological examination showed positive Grimelius staining, marked mitosis, and intense atypism, hence, the tumor was diagnosed as an endocrine cell carcinoma. Twelve years after surgery, the patient is healthy, without any sign of recurrence. We present this novel case of long-term survival and review the literature. 相似文献
10.
The change of the conductivity in the rare earth perovskite oxide took place after the chemisorption of flammable gases. The sensitivity for methanol was highest. From the conductivity change of these perovskite oxides after the injection of methanol, the energy needed to promote an electron from a conducting to a nonconducting state, E=E
c-E
t, could be derived from the equation=A
0 exp (–E/kT). LnCoO3 had the smallest E and H (metal-O), which is the binding energy of oxygen coordinating to the metal ions, but exhibited the highest activity for gas sensing. The gas sensing mechanism was also considered. 相似文献