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101.
This paper deals with the asymptotic model matching problem for square nonlinear systems. This problem has been studied by Di Benedetto and Grizzle via geometric approach. We adopt another approach. It is based on an idea that this problem is similar to the nonlinear servomechanism (output regulation) problem. By means of slight modification of the problem statement, a sufficient condition is given. It is described as the solvability of a certain partial differential equation. Its reduction and approximation methods are proposed. © 1998 John Wiley & Sons, Ltd. 相似文献
102.
Kiyoshi Mizuuchi Kanryu Inoue Yasuyuki Agari Toru Nagaoka Masami Sugioka Motohiro Tanaka Takashi Takeuchi Jun-ichi Tani Masakazu Kawahara Yukio Makino Mikio Ito 《Composites Part B》2012,43(4):2012-2019
Silicon carbide (SiC)-particle-dispersed-aluminum (Al) matrix composites were fabricated in a unique fabrication method, where the powder mixture of SiC, pure Al and Al–5mass% Si alloy was uniquely designed to form continuous solid–liquid co-existent state during spark plasma sintering (SPS) process. Composites fabricated in such a way can be well consolidated by heating during SPS processing in a temperature range between 798 K and 876 K for a heating duration of 1.56 ks. Microstructures of the composites thus fabricated were examined by scanning electron microscopy and no reaction was detected at the interface between the SiC particle and the Al matrix. The relative packing density of the Al–matrix composite containing SiC was higher than 99% in a volume fraction range of SiC between 40% and 55%. Thermal conductivity of the composite increased with increasing the SiC content in the composite at a SiC fraction range between 40 vol.% and 50 vol.%. The highest thermal conductivity was obtained for Al–50 vol.% SiC composite and reached 252 W/mK. The coefficient of thermal expansion of the composites falls in the upper line of Kerner’s model, indicating strong bonding between the SiC particle and the Al matrix in the composite. 相似文献
103.
104.
Akitoshi Hayashi Ryoji Ohtsubo Motohiro Nagao Masahiro Tatsumisago 《Journal of Materials Science》2010,45(2):377-381
Electrochemical performance of the Li2S–P2S5–Cu composite materials was examined in all-solid-state lithium secondary batteries. The 80Li2S·20P2S5 (mol.%) solid electrolyte with the addition of Cu was partially used as an active material with lithium source in all-solid-state
cells. The initial discharge capacity of 110 mAh g−1 (normalized by the weight of 80Li2S·20P2S5–Cu), which corresponds to 400 mAh g−1 (normalized by the weight of Li2S), was obtained in the cell using the 80Li2S·20P2S5–Cu composite electrode with the molar ratio of Li2S/Cu = 48/52. Cycling performance and reaction mechanism of the electrode in the solid-state cell were investigated. 相似文献
105.
Hiroshi Iwai Naoki Shikazono Hisanori Teshima Ryo Kishida Katsuhisa Matsuzaki Motohiro Saito Koichi Eguchi Hideo Yoshida 《Journal of power sources》2010,195(4):955-788
The three-dimensional microstructure of an SOFC anode is quantified using a dual beam focused ion beam scanning electron microscopy (FIB-SEM) system equipped with an energy dispersive X-ray spectroscopy (EDX) unit. The microstructure of the Ni-YSZ anode is virtually reconstructed in a computational field using a series of acquired two-dimensional SEM images. The three-phase boundary (TPB) density and tortuosity factors are carefully evaluated by applying two different evaluation methods to each parameter. The TPB density is estimated by a volume expansion method and a centroid method, while the tortuosity factors are evaluated by a random walk calculation and a lattice Boltzmann method (LBM). Estimates of each parameter obtained by the two methods are in good agreement with each other, thereby validating the reliability of the analysis methods proposed in this study. 相似文献
106.
Airborne endotoxin concentrations in indoor and outdoor particulate matter and their predictors in an urban city 下载免费PDF全文
Endotoxins are an important biological component of particulate matter and have been associated with adverse effects on human health. There have been some recent studies on airborne endotoxin concentrations. We collected fine (PM2.5) and coarse (PM10‐2.5) particulate matter twice on weekdays and weekends each for 48 hour, inside and outside 55 homes in an urban city in Japan. Endotoxin concentrations in both fractions were measured using the kinetic Limulus Amebocyte Lysate assay. The relationships between endotoxin concentrations and household characteristics were evaluated for each fraction. Both indoor and outdoor endotoxin concentrations were higher in PM2.5 than in PM10‐2.5. In both PM2.5 and PM10‐2.5, indoor endotoxin concentrations were higher than outdoor concentrations, and the indoor endotoxin concentrations significantly correlated with outdoor concentrations in each fraction (R2=0.458 and 0.198, respectively). Indoor endotoxin concentrations in PM2.5 were significantly higher in homes with tatami or carpet flooring and in homes with pets, and lower in homes that used air purifiers. Indoor endotoxin concentrations in PM10‐2.5 were significantly higher in homes with two or more children and homes with tatami or carpet flooring. These results showed that the indoor endotoxin concentrations were associated with the household characteristics in addition to outdoor endotoxin concentrations. 相似文献
107.
108.
Yoichi Wada Atsushi Watanabe Kazushige Ishida Masahiko Tachibana Motohiro Aizawa Motomasa Fuse 《Journal of Nuclear Science and Technology》2013,50(5):546-555
A calculation model on intergranular stress corrosion cracking (IGSCC) initiation time of materials used in boiling water reactors (BWRs) has been developed to evaluate effectiveness of water chemistry control for mitigation of the IGSCC. The model was composed of four terms which determine passive film break time: (1) a chemical term based on electrochemical corrosion potential (ECP) and impurity concentration; (2) a mechanical term based on strain rate; (3) a material term based on sensitization; and (4) an irradiation term based on acceleration of corrosion by γ-rays and neutron irradiation. The contribution of the chemical term in the passive film break was calculated based on a deterministic local corrosion model. Then, the local corrosion model was modified by adding mechanical acceleration of the film rupture to treat the IGSCC phenomenon. The model could reproduce the behavioral tendency seen in the slow strain rate tensile test on high carbon contents with sensitization heat treatment (for example, 620°C × 24 h). Under BWR operating conditions, IGSCC initiation time could be extended by a factor of 5 by lowering the electric conductivity from 1.0 to 0.06 μS/cm. If the ECP was reduced below the critical potential by a mitigation method, the IGSCC initiation time was predicted to become sufficiently long for pipings and components. 相似文献
109.
Ikuo Kanno Kazunari Shima Hironobu Shimazaki Yoshiki Yamashita Kenichi Watanabe Masahiko Ohtaka 《Journal of Nuclear Science and Technology》2013,50(10):1020-1033
The authors invented the transXend detector, which measures X-rays as electric currents, and then gives the energy distribution of the X-rays after an unfolding process. In a previous paper, it was shown that the material thickness distributions can be estimated with the transXend detector by using reference points plotted from the electric current ratios, such as the I 2/I 1 ? I 3/I 1 graph, where Ii denotes the electric current measured by the i-th segment of the transXend detector. In this paper, the tomographic images of iodine, aluminum, and the acrylic those surround the other two materials are reconstructed from their material thickness distributions, which are estimated from two X-ray incidence directions. The X-ray event ratios are also used to estimate the material thickness distributions. 相似文献
110.
Yoshiki Yamashita Kazunari Shima Ikuo Kanno Masahiko Ohtaka Makoto Hashimoto Kuniaki Ara 《Journal of Nuclear Science and Technology》2013,50(1):91-97
X-ray computed tomography (CT) with iodine contrast agent is widely employed to locate cancers. However, this method has shortcomings such as high-radiation dose exposure, iodine side effects, and a beam hardening effect. We have been working on the energy-resolved CT measurement method using a novel X-ray detection system, the “transXend” detector, which measures X-rays as electric currents and gives the energy distribution of incident X-rays after analysis. In the present study, we propose a method for low-dose exposure CT that involves the combination of the energy-resolved CT method, which is free from the beam hardening effect, and a harmless contrast agent with high-energy K-edge absorption, such as gold nanoparticles expected as a future contrast agent. Comparisons of radiation dose exposures as functions of aluminum filter thickness at the exit aperture of an X-ray tube and the K-edge energies of contrast agents are described. 相似文献