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51.
Z. F. Zhang Z. M. Sun H. Hashimoto T. Abe 《Journal of the European Ceramic Society》2002,22(16):2957-2961
To synthesize Ti3SiC2 samples, pulse discharge sintering (PDS) technique was utilized to sinter elemental powders of Ti/Si/C with stoichiometric and off-stoichiometric ratios in a temperature range of 1200–1500 °C. The results showed that high purity Ti3SiC2 could not be obtained from the Ti/Si/C powder with molar ratio of 3:1:2, and Ti3SiC2 preferred to form at relatively low sintering temperature for a short time. When 5Ti/2Si/3C and 3Ti/1.5Si/2C powders were sintered for 15 min, the TiC content was respectively decreased to 6.4 and 10 wt.% at 1250–1300 °C. The corresponding relative density of the samples sintered from 5Ti/2Si/3C powder was calculated to be as high as 99% at the temperature above 1300 °C. It is suggested that low-temperature rapid synthesis of Ti3SiC2 would be possible through the PDS technique, provided that the composition of the starting powders should be adjusted to be off-stoichiometric ratio from 3:1:2. 相似文献
52.
Amorphous ternary palladium-based alloys containing platinum group metals as an additional element were prepared by rapid quenching from the molten state and their anodic characteristics were investigated in a 4 mol dm?3 NaCl solution of pH 4 and 80° C. The amorphous alloys containing sufficient quantities of rhodium, platinum or iridium were passivated by anodic polarization and their corrosion rates at high current densities in the chlorine evolution region were extremely low. This fact was attributed to the formation of a highly protective passive film due to both the transformation to the amorphous structure and the addition of rhodium, platinum or indium. The electrocatalytic activities for chlorine evolution of amorphous alloys were higher than those of pure platinum group metals except palladium. In particular, the amorphous Pd41Ir40P19 alloy had the desired stable, high electrocatalytic activity for chlorine evolution and the high overvoltage for oxygen evolution. 相似文献
53.
Yamauchi Toshihiro Akao Yohei Yoshitani Ryota Nakamura Yuichi Hashimoto Masaki 《International Journal of Information Security》2021,20(4):461-473
International Journal of Information Security - Cyberattacks, especially attacks that exploit operating system vulnerabilities, have been increasing in recent years. In particular, if administrator... 相似文献
54.
Norihiro Moriyama Yuta Kawano Qing Wang Ryota Inoue Meng Guo Makoto Yokoji Hiroki Nagasawa Masakoto Kanezashi Toshinori Tsuru 《American Institute of Chemical Engineers》2021,67(7):e17223
Pervaporation (PV) is a membrane technology that holds great promise for industrial applications. To better understand the PV mechanism, PV dehydrations of various types of organic solvents (methanol, ethanol, iso-propanol, tert-butanol, and acetone) were performed on five types of organosilica and two types of silicon carbide-based membranes, all with different pore sizes. Water permeance was dependent on the types of organic aqueous solutions, which suggested that organic solvents penetrated the pores and hindered the permeation of water. In addition, water permeance of various types of membranes in PV was well correlated with hydrogen permeance in single-gas permeation. Furthermore, a clear correlation was obtained between the permeance ratio in PV and that in single-gas permeation, which was confirmed via the modified-gas translation model. These correlations make it possible to use single-gas permeation properties to predict PV performance. 相似文献
55.
Lingyun Lyu Takeshi Hanada Naohiro Yamahira Jun Morita Ryota Yamamoto Ken Itomi Takumi Adachi Sho Kubouchi Shin Horiuchi 《应用聚合物科学杂志》2021,138(45):51443
The distribution of nano-sized silica in binary rubber blends is characterized by scanning transmission electron microscopy (STEM) tomography combined with energy dispersive X-ray spectrometry (EDX). 3D distribution of silica is visualized by STEM-EDX tomography with the tilt-series of silicon elemental maps, while the phase-separated morphologies of polyisoprene rubber (IR) and styrene-butadiene rubber (SBR) are visualized by STEM-tomography in high-angle-annular-dark field (HAADF) mode. The combination of STEM-EDX and STEM-HAADF tomography enables us to determine the distribution of silica between the two rubber phases quantitatively even with high contents of silica up to 70 phr (weight parts per hundred rubber). It is found that silica is preferentially distributed in the SBR phase, but it is also distributed in the IR phase when the IR fraction in the total rubber components is higher than 40 wt%. The preferential distribution of silica in the SBR phase improves the dispersion of the IR domains. This is the first use of this technique for a multicomponent polymer system, showing the advantage to characterize the complicated multicomponent polymer composite morphologies. 相似文献
56.
Kazunori Nagasaka Takeshi Yoshida Yoshihiro Kita Fumio Hashimoto 《International Journal of Machine Tools and Manufacture》1987,27(2)
For optimization of abrasive cut-off operation, wheel wear equation must be identified before the operation is optimized. The equation is obtained by using GMDH algorithm with successive determination of trends containing interactive terms. In the model equation factors of grinding fluid are taken into consideration in addition to the factors of wheel, work material, feed (table speed) and wheel speed. For the identification of the model wheel wear tests are performed under the experimental design treating the above-mentioned factors as independent variables. The grinding ratio (output in the model) can be predicted for combinations of various factors using the model. With the wheel wear equation and machining cost model, the optimum combination of wheel, fluid, feed and wheel speed can be selected for a given work material. The relationships between these variables and the costs are investigated. 相似文献
57.
58.
K. Hashimoto M. YamasakiS. Meguro T. SasakiH. Katagiri K. IzumiyaN. Kumagai H. HabazakiE. Akiyama K. Asami 《Corrosion Science》2002,44(2):371-386
CO2 emissions, which induce global warming, increase with the development of economic activity. It is impossible to decrease the CO2 emissions by suppression of the economic activity. Global CO2 recycling can solve this problem. The global CO2 recycling consists of three district: The electricity is generated by solar cells on deserts. At desert coasts, the electricity is used for H2 production by seawater electrolysis and H2 is used for CH4 production by the reaction with CO2. CH4 which is the main component of liquefied natural gas is liquefied and transported to energy consuming districts where CO2 is recovered, liquefied and transported to the desert coasts. A CO2 recycling plant for substantiation of our idea has been built on the roof of the Institute for Materials Research in 1996. Key materials necessary for the global CO2 recycling are the anode and cathode for seawater electrolysis and the catalyst for CO2 conversion. All of them have been tailored by us. They have very high activity and selectivity for necessary reactions in addition to excellent durability. A pilot plant consisting of minimum units in an industrial scale is going to be built in three years. 相似文献
59.
Sun-Chan Jeong Ichiro Katayama Hirokane Kawakami Yutaka Watanabe Hironobu Ishiyama Nobuaki Imai Yoshikazu Hirayama Hiroari Miyatake Masao Sataka Satoru Okayasu Hiroyuki Sugai Shin-Ichi Ichikawa Katsuhisa Nishio Shinichi Mitsuoka Takamitsu Nakanoya Masahito Yahagi Takanori Hashimoto Kazunori Takada Mamoru Watanabe Tomoko Ishikawa Akihiro Iwase 《Journal of Phase Equilibria and Diffusion》2005,26(5):472-476
For the effective use of short-lived radioactive beams, soon to be available at the Tokai Radioactive Ion Accelerator Complex, the authors have developed a radiotracer method for diffusion studies in solids. The experimental test was performed by the measurement of the diffusion coefficients of Li in a sample of the compound βLiAl using an α-emitting radiotracer of 8Li (T1/2=0.84 s). It was found that the time-dependent yields of the α particles from the diffusing 8Li that was initially implanted in the sample could be used as a measure of the diffusivity of the tracer in a nondestructive way. The method was applied to measure the self-diffusion coefficients of Li in βLiGa, and for investigating how the Li diffusion in the Li ionic conductors is affected by the concentration of atomic defects (i.e., the existence of the atomic vacancies of Li and the defects in Ga sites that are replaced by Li). 相似文献
60.
Wang P Behan G Kirkland AI Nellist PD Cosgriff EC D'Alfonso AJ Morgan AJ Allen LJ Hashimoto A Takeguchi M Mitsuishi K Shimojo M 《Ultramicroscopy》2011,111(7):877-886
Scanning confocal electron microscopy (SCEM) offers a mechanism for three-dimensional imaging of materials, which makes use of the reduced depth of field in an aberration-corrected transmission electron microscope. The simplest configuration of SCEM is the bright-field mode. In this paper we present experimental data and simulations showing the form of bright-field SCEM images. We show that the depth dependence of the three-dimensional image can be explained in terms of two-dimensional images formed in the detector plane. For a crystalline sample, this so-called probe image is shown to be similar to a conventional diffraction pattern. Experimental results and simulations show how the diffracted probes in this image are elongated in thicker crystals and the use of this elongation to estimate sample thickness is explored. 相似文献