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161.
Tomoya Nagira Shugo Morita Hiroyoshi Yokota Hideyuki Yasuda Christopher M. Gourlay Masato Yoshiya Akira Sugiyama Kentaro Uesugi Akihisa Takeuchi Yoshio Suzuki 《Metallurgical and Materials Transactions A》2014,45(12):5613-5623
Synchrotron X-ray radiography at 125 frames per second was used to study deformation mechanisms in semi-solid Fe-C alloys at high solid fraction and shear strain rates of 10?1/s. An image correlation approach was also used to quantify the shear strain fields and study shear-induced dilation and the origin of shear cracking. It was shown that, at high solid fraction (90 to 93 pct solid), rearrangement including rotation and translation of solid particles became restricted and shear strain localized into narrow liquid-filled channels/fissures. Shear cracking was shown to originate from inadequate liquid flow into the expanding spaces between solid particles caused by shear-induced dilation. At lower solid fraction (~85 pct solid), solid particles rearranged with a significantly higher component of rotation leading to more shear-induced dilation and a wider shear band. 相似文献
162.
This paper describes a direct‐power‐controlled CVCF inverter and presents its experimentally examined operation characteristics. The most important feature of this strategy is the direct selection of the switching states of the CVCF inverter to restrict errors between the feedback and command values of active and reactive power. In addition, this paper presents a theoretical analysis of the relationship between the instantaneous power and the switching state, which is essential for deriving a switching‐state table for the controller. The feasibility of the proposed method was verified through several computer simulations and experimental tests using a 2.0‐kVA prototype setup. The output voltages were confirmed to be stable sinusoidal waveforms with a total harmonic distortion of 1.13% under nonlinear load conditions. Excellent voltage balance was achieved by the proposed strategy even under unbalanced load conditions. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 174(3): 62–69, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21023 相似文献
163.
Sintering Kinetics at Isothermal Shrinkage: Effect of Specific Surface Area on the Initial Sintering Stage of Fine Zirconia Powder 总被引:1,自引:0,他引:1
Koji Matsui Akira Matsumoto Masato Uehara Naoya Enomoto Junichi Hojo 《Journal of the American Ceramic Society》2007,90(1):44-49
The isothermal shrinkage behaviors of fine zirconia powders (containing 2.8–2.9 mol% Y2 O3 ) with specific surface areas of about 6 and 16 m2 /g were investigated to clarify the effect of specific surface area on the initial sintering stage. The shrinkage of powder compact was measured under constant temperatures in the range of 1000°–1100°C. The increase in specific surface area enhanced the densification rate with increasing temperature. The values of activation energy ( Q ) and frequency-factor term (β0 ) of diffusion at initial sintering were estimated by applying the sintering-rate equation to the isothermal shrinkage data. The Q of diffusion changes little but the β0 increases with the increase in specific surface area. It is therefore concluded that the increase in the specific surface area of fine zirconia powder enhances the shrinkage rate because of an increase in the β0 at the initial stage of sintering. 相似文献
164.
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166.
According to Hebb's cell assembly theory, the brain has the capability of function localization. On the other hand, it is suggested that in the brain there are three different learning paradigms: supervised, unsupervised, and reinforcement learning, which are related deeply to the three parts of brain: cerebellum, cerebral cortex, and basal ganglia, respectively. Inspired by the above knowledge of the brain in this paper we present a brainlike learning system consisting of three parts: supervised learning (SL) part, unsupervised learning (UL) part, and reinforcement learning (RL) part. The SL part is a main part learning input–output mapping; the UL part is a competitive network dividing input space into subspaces and realizes the capability of function localization by controlling firing strength of neurons in the SL part based on input patterns; the RL part is a reinforcement learning scheme, which optimizes system performance by adjusting the parameters in the UL part. Numerical simulations have been carried out and the simulation results confirm the effectiveness of the proposed brainlike learning system. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(1): 32–39, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20600 相似文献
167.
H Kataoka A Tsuda Y Tsuda A Baba H Yoshida R Hirasawa Y Tobimatsu M Nishiguchi M Semma Y Ito 《Canadian Metallurgical Quarterly》1997,20(6):714-716
We found that an antigen-specific anaphylaxis was induced by antigen challenge to the abdominal wall, ear auricle, or subcutaneous tissue in mice sensitized 9 days previously with antigen and adjuvant. The anaphylactic reaction was detected by vascular permeability at the injected site 7 minutes after challenge, which was the best time for estimation. A novel method (AW method) for induction and detection of the anaphylactic reaction in mice was established using the abdominal wall as the challenge site. This method could detect the anaphylactic response in mice 1 to 3 weeks after sensitization. The increase in vascular permeability was completely inhibited by administration of diphenhydramine. 相似文献
168.
We investigated the diffusion process of H2O2 generated during O2 reduction at a Pt microdisk electrode used as a generator for scanning electrochemical microscopy (SECM). First, the amount of O2 consumption and generated H2O2 at the Pt generator electrode are estimated using a detector electrode installed in the SECM. Based on the results, a large amount of O2 consumption and generated H2O2 are detected at the center of each generator electrode. According to the measurement, the O2 starvation and H2O2 detection currents can be defined. Subsequently, the O2 starvation and H2O2 detection currents are measured by varying the generator size. As a result, these currents decrease with a decrease in the generator electrode size, however, the H2O2 diffusion process is changed for the generator diameter of less than 50 μm. Finally, the O2 starvation and H2O2 detection measurements were conducted using a Nafion-coated Pt microdisk electrode. The amount of O2 consumption is not suppressed, while the amount of generated H2O2 decreases with the Nafion layer prepared on the Pt electrode. This result indicates that the thickness of the H2O2 diffusion layer in the H2SO4 solution is dramatically diminished by coating the Nafion layer on the Pt generator. 相似文献
169.
Sinterability of various high-purity magnesium oxide powders 总被引:3,自引:0,他引:3
Kiyoshi Itatani Masayuki Nomura Akira Kishioka Makio Kinoshita 《Journal of Materials Science》1986,21(4):1429-1435
The sinterability of high-purity MgO powders with different production histories was investigated to make clear the relationship between the powder characterization, the densification processes, and the changes in microstructure both with increasing temperature at a rate of 10° C min–1 and at a fixed temperature of 1450° C for 5 h. The densification behaviour and the changes in microstructure of these compressed bodies were affected chiefly by their original surface activity and degree of agglomeration, depending on the production histories: (i) the ultra-fine and well-dispersed powder prepared by the vapour-phase oxidation process showed that densification proceeded with an appreciable grain growth with few closed pores remaining; (ii) powder derived from the sea-water magnesia process showed that the densification behaviour was affected by the species of magnesium salt, i.e. basic magnesium carbonate or magnesium hydroxide, used as a precursor; however, whichever magnesium salt was used, its sintered compact showed similar closed porosities and grain-size distributions; (iii) powder derived from the spark-discharge process contained skeletons of the original Mg(OH)2 particles; however, the densification proceeded gradually with slow grain growth, reflecting the fact that the powder has a moderate surface area (36 m2 g–1). The sintered compact from (iii) had a small closed porosity and the smallest grain-size distribution among the compacts used in this investigation. 相似文献
170.
The liquid lead-bismuth eutectic (PbBi) has good compatibility with water, which is different from sodium. It is expected that the PbBi could be used as a coolant of the deep sea fast reactor (DSFR). Physics analysis of the PbBi-cooled small reactor cores with and without inner control rods performed using the computer program of a neutronics code system (SRAC95) shows that PbBi is suitable for the coolant of small reactors as well as NaK. 相似文献