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61.
Ping Shen Hidetoshi Fujii Taihei Matsumoto Kiyoshi Nogi 《Journal of the American Ceramic Society》2005,88(4):912-917
Wetting phenomena and the effect of alumina surface orientation on the wettability in Si/α-Al2 O3 system were studied by an improved sessile drop method using , , C(0001) faces of single crystals and polycrystals at 1723 K in a reducing Ar–3% H2 atmosphere. The contact angles show a vibration behavior for all the single crystals but to a less extent for the polycrystals. The extent of the vibration correlates not only with the reaction intensity but also with the stability of the Si droplet on the alumina surfaces. The interfacial reaction leads to the formation of a series of reaction rings, which is more serious at the single crystal surfaces. More importantly, the wettability is dependent on the alumina surface orientation, with the intrinsic contact angles being about 98±2°, 101±1°, 69±1°, and 98±2°, respectively, for the , , C(0001) and polycrystal α-Al2 O3 substrates. The much smaller contact angle for molten Si on the C(0001) surface is explained by the favorable reduction in the Si/α-Al2 O3 interfacial free energy by the terminated and enriched aluminum atoms at the reconstructed surface. The importance of the aluminum presence at the Si/α-Al2 O3 interface to the wettability of this system was further demonstrated by a substantial improvement in the wettability of the α-Al2 O3 substrates by Si–Al alloys. 相似文献
62.
T. Matsumoto N. Shimizu T. Itoh T. Iida A. Nishioka 《Journal of the American Oil Chemists' Society》1982,59(12):521-523
24-Methylcholesta-5,E-22-dien-3β-ol (C28 Δ5,22-sterol) was separated from the unsaponifiable matters of the following eight seed oils of Brassica species:Brassica campestris (candle I and II and torch),B. napus (tower and midas),B. juncea (brown and oriental mustards), andB. alba (yellow mustard). The configuration at C-24 methyl group of the respective sterols was evaluated by13C NMR spectroscopy. All the C28 Δ5,22-sterols in the Brassica seed oils were found to contain the C-24 epimer of brassicasterol,trans-22-dehydrocampesterol, in the range of ca. 10–30%. 相似文献
63.
Yasushi Murakami Taki Matsumoto Kiyochika Yahikozawa Yoshio Takasu 《Catalysis Today》1995,23(4):383-389
The sol-gel process for the hydrolysis and polycondensation of tin tetra-n-butoxide in butanol was followed by viscosity measurements. The precipitation of tin-containing ultrafine particles was observed without any variation in the solution viscosity in the absence of diethylene glycols, while the viscosity increase was made without any precipitation by the addition of diethylene glycol. The induction period and the rate of the viscosity increase after the induction period was independent of the diethylene glycol content but depended upon the water content. The Monte Carlo simulation data were consistent with data for the viscosity experiment. The simulation was based on a kinetic model of the slow hydrolysis of tin tetra-n-butoxide, the reverse reaction of hydrolysis, and the polycondensation of the hydroxy derivatives. 相似文献
64.
Gabriela Brunosi Medeiros Paulo Ricardo de Souza Karina Miyuki Retamiro Celso Vataru Nakamura Edvani Curti Muniz Elisângela Corradini 《应用聚合物科学杂志》2021,138(36):50898
The production of polymer fibers from the combination of zein and PEO might have great potential in the field of biomaterial. Zein/PEO fibers were obtained in this work through solution electrospinning. An experimental design, 24-1, was used for evaluating the influences of PEO content in the blend, distance from the needle tip to the collector, applied electric voltage and solution flow for average fiber diameter and relative-yield process. Beyond this, the relationship between PEO content in the blend and the fiber properties were evaluated through FTIR, DSC, TG, tensile tests, and cytotoxic tests. The factor that exerts the greatest effect on the average fiber diameter response was the electrical voltage. The increase in PEO content in the blend decreased the thermal stability and increased the degree of the fibers' crystallinity. The mechanical tests showed that fibers with higher elongation were obtained at richer PEO blends. The fibers presented cytocompatible characteristics. 相似文献
65.
The anodic behavior of Mg-Al-Zn alloy (AZ91D) under low potential electrolysis in 3 M KOH solutions was studied with and without addition of 0.5-5 M Na2SiO3. Anodic films incorporating silicon were formed during electrolysis, and the films formed under constant potential electrolysis at 4 V in 3 M KOH solution with Na2SiO3 were uniform and thicker than the films formed without Na2SiO3. A few at% of silicon was present as Mg2SiO4 in the films, although the main compound was Mg(OH)2. The corrosion resistance of the films formed in solutions with Na2SiO3 increased in an anodic polarization test in 0.1 M KCl solution. 相似文献
66.
The extended X-ray absorption fine structure (EXAFS) method and transmission electron microscopy (TEM) have been used for characterizing the local structure and morphology of ferric oxyhydroxides, α-FeOOH and γ-FeOOH, with and without chromium. These ferric oxyhydroxide powders were prepared from aqueous solutions containing iron and chromium ions. Radial structural functions for iron obtained by Fe K edge EXAFS spectra showed that the linkage of structural units formed by FeO6 octahedra in γ-FeOOH is distorted by chromium addition, while such distortion in α-FeOOH is not clearly detected. On the other hand, Cr K edge EXAFS spectra showed that the local structure around chromium does not necessarily correspond to the local structure around of iron, which is observed by Fe K edge EXAFS spectra. This suggests that the structural units containing iron and chromium are heterogeneously distributed in these ferric oxyhydroxides. The local structural information was discussed coupled with morphological features of these ferric oxyhydroxides observed by TEM. 相似文献
67.
Go Kobayashi Hiroki Hatakeyama Kosuke Ota Yohei Nakada Takashi Kaburagi Takashi Matsumoto 《Multimedia Tools and Applications》2016,75(6):3081-3119
We attempted to predict activity/dominance for soccer games, where activity is defined as the degree of activity of the game as perceived by the viewer, whereas dominance is the degree at which the viewer perceives a particular team to dominate over the other team. Such activity/dominance information would help a layman viewer understand the game. It would also enable construction of an automatic digest creation system that extracts scenes having high activity/dominance. There are two facets of this study: 1. The main part of the underlying prediction model consists of a Stick-Breaking Hidden Markov Model, where the data automatically estimates the number of states of the Markov process behind the data. 2. The data used in this paper is vector time-series data consisting of player, referee, and ball positions, together with team information, acquired by a set of fixed cameras. The problem was approached with a Bayesian framework where learning and prediction were implemented by three different methods: Markov Chain Monte Carlo, Expectation Maximization, and Variational Bayes. The proposed method was tested using a dataset consisting of 10 professional soccer games and was compared against standard regression methods. 相似文献
68.
Emad Shihab Akinori Ihara Yasutaka Kamei Walid M. Ibrahim Masao Ohira Bram Adams Ahmed E. Hassan Ken-ichi Matsumoto 《Empirical Software Engineering》2013,18(5):1005-1042
Bug fixing accounts for a large amount of the software maintenance resources. Generally, bugs are reported, fixed, verified and closed. However, in some cases bugs have to be re-opened. Re-opened bugs increase maintenance costs, degrade the overall user-perceived quality of the software and lead to unnecessary rework by busy practitioners. In this paper, we study and predict re-opened bugs through a case study on three large open source projects—namely Eclipse, Apache and OpenOffice. We structure our study along four dimensions: (1) the work habits dimension (e.g., the weekday on which the bug was initially closed), (2) the bug report dimension (e.g., the component in which the bug was found) (3) the bug fix dimension (e.g., the amount of time it took to perform the initial fix) and (4) the team dimension (e.g., the experience of the bug fixer). We build decision trees using the aforementioned factors that aim to predict re-opened bugs. We perform top node analysis to determine which factors are the most important indicators of whether or not a bug will be re-opened. Our study shows that the comment text and last status of the bug when it is initially closed are the most important factors related to whether or not a bug will be re-opened. Using a combination of these dimensions, we can build explainable prediction models that can achieve a precision between 52.1–78.6 % and a recall in the range of 70.5–94.1 % when predicting whether a bug will be re-opened. We find that the factors that best indicate which bugs might be re-opened vary based on the project. The comment text is the most important factor for the Eclipse and OpenOffice projects, while the last status is the most important one for Apache. These factors should be closely examined in order to reduce maintenance cost due to re-opened bugs. 相似文献
69.
T. Kimura T. Tokuda Y. Nakada T. Nokajima T. Matsumoto A. Doucet 《Pattern Analysis & Applications》2013,16(1):55-67
Mixture models are ubiquitous in applied science. In many real-world applications, the number of mixture components needs to be estimated from the data. A popular approach consists of using information criteria to perform model selection. Another approach which has become very popular over the past few years consists of using Dirichlet processes mixture (DPM) models. Both approaches are computationally intensive. The use of information criteria requires computing the maximum likelihood parameter estimates for each candidate model whereas DPM are usually trained using Markov chain Monte Carlo (MCMC) or variational Bayes (VB) methods. We propose here original batch and recursive expectation-maximization algorithms to estimate the parameters of DPM. The performance of our algorithms is demonstrated on several applications including image segmentation and image classification tasks. Our algorithms are computationally much more efficient than MCMC and VB and outperform VB on an example. 相似文献
70.
The technology to fabricate high-aspect ratio and micro curved surface structures is needed for optical device fabrication such as micro lens, light guiding device, and so on. In this study, micro curved surface structures were fabricated by using novel lithography technique with UV-LED array and rotary stage (Hanai et al. in Proceedings of the 22nd sensor symposium, pp 516–519, 2005). Smooth surface structures can be fabricated in this technique, because UV-LED which has wide directivity characteristics makes the difference of the UV dose. In addition, the structures can be formed with high uniformity in large area by only one exposure process, because rotation reduces the unevenness of exposure. This technique can control the shapes of structures by changing exposure time and applying gray scale mask method (Waits et al. in Sensors Actuat A 119:245–253, 2005). We fabricated structures of hemisphere, semi-cylinder, and semi-cone by using this technique. High-aspect ratio structures were obtained and they had smooth curved surface. Then, they were used for micro lens fabrication. By using molding technique, micro lenses of the UV curable resin were fabricated on the silicon wafer. 相似文献