巻号一覧
52 巻, 8 号
August
選択された号の論文の14件中1～14を表示しています
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研究
研究
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斉藤 貴伸, 武本 聡2005 年 52 巻 8 号 p. 571-575
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスIn this study initial permeability and permeability under applying DC bias were investigated with several Fe-Si-Al compressed cores made by changing green densities and particle shapes. We concluded as follows.
Initial permeability depends on not only green density but also particle shape. It becomes high as packing density becomes high, and it is high with the particle that has larger aspect ratio. As a result of analysis using Ollendorf's equation, it is suggested that effective demagnetizing factor is small with the particle that has large aspect ratio, resulting in high permeability.
Permeability under applying DC bias can be explained in the view of magnetizing magnetic flux density. Permeability at high magnetic flux density is independent of particle shape, and depends on only green density.抄録全体を表示PDF形式でダウンロード (772K) -
品川 一成, 横田 耕三, 白川 寛, 冨野 寿和, 村井 俊介2005 年 52 巻 8 号 p. 576-580
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスVariations in microstructure and sintering behavior of metal/ceramic powder compacts with mixing ratio are examined by using alumina and stainless steel powder particles. Inhomogenous microstructure of the compacts can be observed as sharp separate peaks on the curve of pore size distribution. Mixture homogeneity of the compacts, which is estimated from the green density, increases with decreasing the volume fraction of strainless steel. Gaining the size of alumina powder also makes the mixture homogeneity large. Isolated stainless steel particles in homogenous microstructure do not bond together even in sintering process and may only inhibit the uniform densification of alumina powder. Although the alumina powder regions in the mixtures shrink locally, pores around the stainless steel particles are not eliminated, and may result in low density of sintered body.抄録全体を表示PDF形式でダウンロード (873K) -
飯泉 清賢, 関谷 千春, 岡田 繁, 宍戸 統悦, 工藤 邦男2005 年 52 巻 8 号 p. 581-585
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスNbB2 (AlB2-type, hexagonal) powder was synthesized by ball milling of Nb-B (1 : 2) mixture using planetary ball mill with balls of 5 mm, 9 mm or 16 mm diameter, and the effect of the ball sizes on the preparation of NbB2 was examined. When milled with balls of 5 mm, 9 mm and 16 mm diameters, the starting time of the NbB2 formation was 20 hrs, 10 hrs and 5 hrs, respectively, and the single phase of NbB2 was obtained in 50 hrs, 30 hrs and 20 hrs, respectively. The time required for the formation of the NbB2 single phase decreased with the increase in the ball size. The lattice parameters of the NbB2 obtained were a = 0.3112 nm, c = 0.3276 nm. The specific surface area of the NbB2 powder decreased with increase in the ball size. The average particle size of the NbB2 powder obtained by milling with the 5 mm diameter balls for 50 hrs was approximately 370 nm. The contaminant in NbB2 powder from the vial and balls decreased with decrease in the ball size.抄録全体を表示PDF形式でダウンロード (786K)
特集 電池材料―SOFC (固体酸化物燃料電池) と二次電池材料―
総報
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武田 保雄2005 年 52 巻 8 号 p. 588
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスPDF形式でダウンロード (137K)
受賞記念講演
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Nobuya Machida2005 年 52 巻 8 号 p. 589-598
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスDevelopment of all-solid-state lithium batteries is strongly desired to replace commercially available lithium-ion batteries using conventional electrolyte solutions, because the all-solid-state batteries have some advantages, such as high reliability and high safety performance. For the development of the all-solid-state lithium batteries, non-flammable lithium-ion conducting solid electrolytes and also positive and negative electrode materials suitable for the all-solid-state batteries are indispensable materials. Phosphorus-sulfide based lithium-ion conducting materials have been prepared by a high-energy ball-milling process. The solid electrolytes in the system Li2S-P2S3-P2S5 show high lithium-ion conductivity over 6×10-4 Scm-1 at room temperature and have been prominent electrochemical stability. New Li-Si alloy has been also prepared by the high-energy ball-milling process and investigated as negative electrode materials for the all-solid-state batteries. The new alloy shows large specific capacity about 300 mAhg-1 and good charge-discharge reversibility.抄録全体を表示PDF形式でダウンロード (1761K)
研究
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Yasuro Ikuma, Shinya Nagasawa, Nao Hayashi, Michiyo Kamiya2005 年 52 巻 8 号 p. 599-602
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスSolid solution of the CeO2-YO1.5 system was studied extensively using X-ray diffraction, Raman spectroscopy and transmission electron microscopy. The results of X-ray diffraction analysis indicate that the solid solution was in fluorite structure over the compositional range 0-30mol%YO1.5. The results of Raman spectroscopy reveal that at 40-70mol%YO1.5, samples were fundamentally in fluorite structure but there was disorder formation that produced many satellite peaks in the X-ray diffraction patterns. At 90-100mol%YO1.5, the solid solution was in rare earth C-type structure.抄録全体を表示PDF形式でダウンロード (602K) -
勝山 茂, 山田 豪, 原 茂太2005 年 52 巻 8 号 p. 603-607
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスPbO2 powders, which are the positive active materials in the lead-acid battery, were mechanically milled with Sb2O3 powders. It is well known that Sb contained in the grid of lead-acid battery is useful for the protection of the premature capacity loss. Before milling, most of PbO2 powders consist of tetragonal β-phase, but in the progress of milling process, they were transformed to orthorhombic α-phase. The intensity of X-ray diffraction peaks of Sb2O3 decreases with increasing milling time, and after the milling of 5 hours, they almost disappear, which indicates that the alloying between PbO2 and Sb2O3 proceeds during milling process. The intensity of the reduction peak in the cyclic voltammetry (CV) curve of the electrode constructed from the PbO2 powders is larger than that of the electrode constructed from PbO2 powders added with Sb2O3. The discharge capacity of the electrode constructed from PbO2 powders increases with increasing milling time, but that of the electrode constructed from PbO2 powders added with Sb2O3 is rather reduced. The difference of the properties between these two electrodes may be ascribed to the difference of the microscopic structure of PbSO4 particles, which are formed during the discharging process.抄録全体を表示PDF形式でダウンロード (872K)
特集 炭素系機能材料
総報
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阪田 祐作2005 年 52 巻 8 号 p. 610
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスPDF形式でダウンロード (101K)
総説
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小田 廣和, 合田 学, 箕浦 晋作, 山下 曜2005 年 52 巻 8 号 p. 611-618
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスThe removal of electrolytes from aqueous solution and regeneration operation of electrodes was carried out using a flow through capacitor. The surface area and micropore volume of activated carbon electrode contributed to the amount of removed electrolytes. Introduction of surface acidic functional groups on the electrode promoted the removal (rate and capacity) remarkably, but the amount of functional groups had restriction. The adsorption-desorption property of many different sorts of electrolytes was divided into alkali, alkaline earth and transition metal.
On the other hand, based on the above results, we attemped to prepare electrodes of electric double layer capacitor to increase capacity. In the case of the aqueous electrolyte, the electric capacity depended more on oxygen functional groups than on BET surface area. A maximum of 30% increase in electric capacity was obtained by using ACFs with different amount of oxygen functional groups between the positive electrode and the negative one. It was attributed to that a certain number of functional group promotes not only the wettability of electrodes but also the negative charge of electrodes leading to an increase in capacity. Also, the characteristics of the electrodes after 30000 cycle charge-discharge were determined to confirm the reliability in an extended cycle operation.抄録全体を表示PDF形式でダウンロード (1328K)
研究
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林 秀考, 武田 大輔, 岸本 昭2005 年 52 巻 8 号 p. 619-623
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスThe electrodeposition of Cu-graphite composite film from copper sulfate bath containing graphite particle has been studied. The graphite particles were oxidized with nitric acid in order to introduce surface oxides. The role of the functional groups on the graphite edge during Cu-graphite composite plating was evaluated by the potentiometric titration method. The titration curve obtained in the presence of graphite particles and that without graphite particles crossed over each other at the pH 2.45 which is probably pKa of the compound in the presence of Cu2+ in the bath. However, this value is found to be lower than the pH 3 in the same solution without Cu2+ ion. This phenomena might be recognized by the adsorption of Cu2+ ion on the functional group of the graphite at the pH higher than the pKa value. Upon analyzing the surface morphology of the Cu-graphite composite coating, it is found that the specific ordered structure of the coating can be fabricated by controlling the pH of the bath.抄録全体を表示PDF形式でダウンロード (1247K) -
寺下 敬次郎, 片山 剛, 李 相録2005 年 52 巻 8 号 p. 624-629
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスIn this study, to establish the method for evaluating the dispersion state of fillers quantitatively, carbon fiber was kneaded and dispersed into the base materials. And fractal dimension, area ratio, and the length of carbon fiber were measured by image analysis. From these values, the dispersion state of carbon fiber and whether the network of carbon fiber was good or bad were evaluated quantitatively. The results showed that by using fractal dimension and its coefficient of variation, coefficient of variation of area ratio, and the rest length ratio of carbon fiber, it was possible to evaluate the dispersion state of carbon fiber and whether the network of carbon fiber was good or bad quantitatively, that is the evaluation method of the dispersion state could be established. Using this method, kneading and dispersed process was also modeled, and the operation condition was discussed by using this model.抄録全体を表示PDF形式でダウンロード (1047K) -
三木 雅道, 菊地 丈幸2005 年 52 巻 8 号 p. 630-634
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスElectromagnetic wave absorption characteristics and electrical resistivities of the unsaturated polyester specimens containing 20-60 mass% of Bincho-charcoal and 10-42.5 mass% of bamboo charcoal powders were measured. The specimens containing 33.3-50.0% of Bincho-charcoal powder absorbed remarkably the electromagnetic wave of the frequency range of 2.5-3.5 GHz and the specimens containing 12.1-18.0% of bamboo charcoal powder also absorbed remarkably that of the frequency range of 4.0-15 GHz. The specimens which showed the remarkable absorptions had the electrical resistivities of the range of 103-102Ω · cm and therefore these electrical resistivity values seems to have been suitable for converting the energy of the electromagnetic wave at the above frequency range into the energy of heat.抄録全体を表示PDF形式でダウンロード (988K) -
三木 雅道, 小濱田 卓, 岡室 智行, 菊地 丈幸, 畠山 賢一2005 年 52 巻 8 号 p. 635-639
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスElectromagnetic wave absorption characteristics and electrical resistivity of the 2-6 mm thick cement mortar board specimens containing 6-16 mass% of Bincho-charcoal powder were measured by free space method and four probe method, respectively. The 2-4 mm thick specimens containing 8-10% of Bincho-charcoal powder absorbed remarkably the electromagnetic waves with frequencies of 3-8 GHz. Especially about 2.5 mm thick specimen containing 10% of Bincho-charcoal powder absorbed remarkably the electromagnetic wave of 5.8 GHz, which is used for intelligent transportation systems (ITS). It is clarified that these specimens are dielectric absorbers with the electrical resistivities of above 108Ω · cm.抄録全体を表示PDF形式でダウンロード (902K) -
内田 有紀子, 大石 響子, 中西 真, 藤井 達生, 高田 潤, 草野 圭弘, 菊池 丈幸2005 年 52 巻 8 号 p. 640-645
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスWe have successfully prepared Carbon/Fe-Co alloy composites starting from metal organic precursors synthesized by polymerized complex method. The carbon/Fe-Co alloy composites were obtained after the carbonization of the precursors heat-treated at ambient pressure and lower temperatures ranging from 500 to 700°C in N2 gas flow. Crystalline sizes of both carbon matrix and Fe-Co alloy particles were determined by X-ray diffraction measurements as a function of the Co concentration and the carbonized temperature. The alloy particles were widely dispersed in the carbon matrix and the particle size carbonized at 600°C was about 20∼50 nm observed by scanning electron microscopy. The composite carbonized at 600°C had very small coercivity of 14 Oe and exhibited relatively large permeability spectra at frequency of GHz range.抄録全体を表示PDF形式でダウンロード (848K)
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