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排序方式: 共有310条查询结果,搜索用时 15 毫秒
1.
Tatsuro Tanaka Yoshifumi Maeda Shinji Yamamoto Toru Iwao 《Electrical Engineering in Japan》2019,207(1):15-23
The arc welding has been used in various welding methods because it is inexpensive and high in strength after welding. However, it is a problem that accidents such as collapse of the bridge occur because of the welding defects. The welding of low cost and high productivity is required without the welding defects. The pulsed TIG welding is inexpensive and capable of high‐quality welding. The electromagnetic force contributing to penetration changes because the transient response of arc temperature and iron vapor generated from anode occurs. However, the analysis of pulsed TIG welding with metal vapor has been elucidated only metal vapor concentration near anode with transient phenomenon and heat flux. Thus, the theoretical elucidation of penetration depth with control factor has not been researched. In this paper, the contribution of metal vapor mass at the periphery part of pulsed arc to the electromagnetic force in the weld pool is elucidated. As a result, the iron vapor mass at periphery part decreased with increasing the frequency. The iron vapor was stagnated at axial center within one cycle. The electromagnetic force to the penetration depth direction in weld pool increased at axial center. Therefore, the metal vapor mass at periphery part plays an important role for the electromagnetic force increment at axial center. 相似文献
2.
Iwao Shimizu Yuji Naito Iwao Yamaguchi Katsuyuki Kaiho Hitoshi Mizoguchi Satoru Yanabu 《Electrical Engineering in Japan》2008,164(1):52-61
Using conventional high‐temperature superconducting wire, a model superconducting fault current limiter (SFCL) is made and tested. Solenoid coil using Bi2223 silver sheath wire is so made that inductance is as small as possible and a vacuum interrupter is connected in series to it. A conventional reactor coil is connected in parallel. When the fault current flows in this equipment, superconducting wire is quenched and current is transferred into the parallel coil because of voltage drop of superconducting wire. This large current in parallel coil actuates magnetic repulsion mechanism of vacuum interrupter. Due to opening of vacuum interrupter, the current in superconducting wire is broken. By using this equipment, current flow time in superconducting wire can be easily minimized. On the other hand, the fault current is also easily limited by large reactance of parallel coil. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 164(1): 52–61, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20315 相似文献
3.
T Iwao A Toyonaga H Harada K Harada S Ban M Ikegami K Tanikawa 《Canadian Metallurgical Quarterly》1994,40(3):277-280
We studied oxygen saturation (SaO2) using a pulse oximeter in 120 patients undergoing non-sedated diagnostic upper gastrointestinal endoscopy. The baseline SaO2 was 98.3 +/- 1.0%. During the procedure, absence of oxygen desaturation (SaO2 > or = 95%) was found in 56%, mild oxygen desaturation (95% > SaO2 > or = 90%) in 35%, and severe oxygen desaturation (SaO2 < 90%) in 9%. Age (p = 0.56), gender (p = 0.47), smoking (p = 0.35), hemoglobin level (p = 0.52), body mass index (p = 0.27), or total endoscopy time (p = 0.72) was not related to the degree of oxygen desaturation. These results suggest that oxygen desaturation is frequently observed during non-sedated diagnostic upper gastrointestinal endoscopy although severe oxygen desaturation, which may induce rare but serious cardiopulmonary events, is not common. Furthermore, we cannot predict in which patients desaturation will occur. We therefore recommend continuous monitoring of arterial oxygenation in all patients during the procedure. 相似文献
4.
Takashi Hayashi Makoto Mihoya Iwao Yamai Hajime Saito Shin-Ichi Hirano 《Journal of Materials Science》1987,22(4):1305-1309
Needle-like or wool-like Al2O3 whiskers can be grown on a substrate by the hydrolysis of aluminium fluoride vapour. Effects of the growth conditions on the morphology of the crystals and growth processes of the whisker were investigated, and the optimum growth condition of whiskers was examined. Adequate vapour pressure conditions of the reactant gases for the growth of the wool-like whisker were found to be
. Aluminium oxyfluoride was assumed to be the most probable intermediate species for the growth of Al2O3 whiskers. A variety of crystal morphologies are also shown and described with respect to the experimental conditions. 相似文献
5.
6.
Gallium activity in the B2 phase regions of both binary Co–Ga and ternary Co–Ga–Sb systems was measured by EMF method with stabilized zirconia solid electrolyte The temperature range was 1073–1273 K and Sb concentrations were 1, 2 and 3 mol fractions. Ga activity at 1173 and 1273 K increases sharply in Ga rich region and the addition of Sb to the CoGa phase increases Ga activity. Activity change corresponds to the lattice parameter change with Sb addition to the CoGa phase. 相似文献
7.
Kuramochi K Suzuki K Yamazaki T Mitsuishi K Furuya K Hashimoto I Watanabe K 《Ultramicroscopy》2008,109(1):96-103
The structure and composition of the 1/4{110} twin boundary in alpha-Zn7Sb2O12 have been determined by using quantitative high-angle annular dark field scanning transmission electron microscopy (HAADF STEM) analysis. The noise in the experimental HAADF STEM images is reduced by using the maximum entropy method and average processing, and the parameters used in dynamical simulations are experimentally determined. From the analysis, it has been found that octahedral sites in the twin boundary slightly shift parallel to the [110] direction, and a reduction of the Sb concentration at the octahedral sites on the plane adjacent to the twin boundary was detected. The reduction was measured from three regions in the same twin boundary, and the Sb concentrations were 4 +/- 3, 8 +/- 3 and 19 +/-2 at% from 33 at%. 相似文献
8.
A simple low-vacuum coater has been fabricated by using a vacuum resin degassing chamber, in which an aluminum effusion cell is heated by a soldering iron. Our developed vacuum coater presents the versatile methods for depositing paraffin wax for skin-coating the sensing layers of quartz crystal microbalance (QCM). As the increase of the cell temperature, the thickness and inhomogeneity of the wax films were increased. Impedance analyses revealed that the energy dissipation of the QCM was remarkably enhanced with the amount of wax. It was also revealed that the as-deposited wax was fluidic until coagulation by heat radiation. This surface skin coating enhanced the ethyl acetate (EA) sorption capabilities of the polyethylene-sputtered QCM sensor, whereas, it reduced the EA sorption capacity of the d-phenylalanine-sputtered QCM sensor. 相似文献
9.
Khamirul Amin Matori Loy Chee Wah Mansor Hashim Ismayadi Ismail Mohd Hafiz Mohd Zaid 《International journal of molecular sciences》2012,13(12):16812-16821
We report on a recycling project in which α-Al2O3 was produced from aluminum cans because no such work has been reported in literature. Heated aluminum cans were mixed with 8.0 M of H2SO4 solution to form an Al2(SO4)3 solution. The Al2(SO4)3 salt was contained in a white semi-liquid solution with excess H2SO4; some unreacted aluminum pieces were also present. The solution was filtered and mixed with ethanol in a ratio of 2:3, to form a white solid of Al2(SO4)3·18H2O. The Al2(SO4)3·18H2O was calcined in an electrical furnace for 3 h at temperatures of 400–1400 °C. The heating and cooling rates were 10 °C/min. XRD was used to investigate the phase changes at different temperatures and XRF was used to determine the elemental composition in the alumina produced. A series of different alumina compositions, made by repeated dehydration and desulfonation of the Al2(SO4)3·18H2O, is reported. All transitional alumina phases produced at low temperatures were converted to α-Al2O3 at high temperatures. The X-ray diffraction results indicated that the α-Al2O3 phase was realized when the calcination temperature was at 1200 °C or higher. 相似文献
10.
Ismayadi Ismail Mansor Hashim Khamirul Amin Matori Rosidah Alias Jumiah Hassan 《Journal of Superconductivity and Novel Magnetism》2012,25(1):71-77
In this paper the effect of sintering temperature on Ni0.5Zn0.5Fe2O4 is examined closely. The evolution of toward magnetically ordered materials was to be tracked with the parallel evolving
microstructure subjected to sintering temperatures in an ascending order. The starting powder of Ni0.5Zn0.5Fe2O4 was prepared via mechanical alloying and later molded into toroidal samples. After each sintering, we observed the resulting
changes in the materials. The XRD data showed a single phase being formed as early as 600 °C and the peak intensity was increasing
with the sintering temperature indicating an increase in the degree of crystallinity. The BH hysteresis loops showed the evolution
from paramagnetism to moderate ferromagnetism to strong ferromagnetism with microstructural changes. For lower sintering temperatures,
the samples showed paramagnetic behavior dominating the samples. As sintering temperature increased, paramagnetic states decreased
and, at 900 °C, a moderately ferromagnetic state appeared. Sintering at 1000 °C produced a strongly ferromagnetic state giving
a well-formed sigmoid-shape hysteresis loop. 相似文献