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排序方式: 共有1335条查询结果,搜索用时 15 毫秒
91.
Daisuke Tashima Yoshihiro Hamasuna Daisuke Mishima Seiji Kumagai John D. W. Madden 《IEEJ Transactions on Electrical and Electronic Engineering》2014,9(4):343-350
Electrochemical double‐layer capacitors (EDLCs) are devices that store enormous amounts of charge electrostatically when a potential is applied between electrodes of very high surface area (typically made of porous carbon) and an electrolyte. Wider commercialization of this technology has been held back by the lack of ultralow‐cost electrode materials. We demonstrate that used coffee grounds can be processed to form low‐cost electrodes. The surface and electrochemical characteristics of microporous activated carbons from used coffee grounds (CGCs) were measured. First, optimal times and temperatures for carbonization and activation were identified on the basis of Brunauer–Emmett–Teller (BET) surface area, pore volume, and pore size distribution. Second, CGCs were used as polarized electrodes in EDLCs, whose capacitances were evaluated using cyclic voltammetry. The results show that carbonization for 1 h at 600 °C with a heating rate of 300 °C/h, followed by CO2 activation for 2 h at 1000 °C, affords the highest BET surface area (1867 m2/g) compared to other works. The produced CGCs have many micropores of less than 2 nm across, which contribute to the formation of an electric double layer. Capacitors made using these CGCs show the highest capacitance (103 F/g) in 0.8 M (C2H5)4NBF4/PC as an organic electrolyte, which is much higher than the ∼80 F/g typically used in organic‐electrolyte‐based commercial EDLCs, suggesting that coffee grounds are a useful electrode material. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
92.
Yuki Takenaka Norihiro Abe Yoshihiro Tabuchi Hirokazu Taki Shoujie He 《Artificial Life and Robotics》2009,14(2):224-227
This research was aimed at making a robot that can go and get an object designated by the user. We produced a robot control
system that uses pointing and voice control. This control system is composed of two systems. One system is the object instruction
system that uses pointing, and the other is the object instruction system that uses voice. The approximate position of a designated
object is recognized by the object instruction system that uses pointing, and information about the object and instructions
about the operation are conveyed by the object instruction system that uses voice. This time, the object instruction system
that uses pointing has been designed and verified as the first step. A calculation resource to calculate the approximate position
of the designated object is obtained when the user points directly at the object. A robot can be moved around a designated
object by using this system. The object instruction system that uses voice will be constructed in future work. 相似文献
93.
Yoshihiro Itoh Fumiya Sahara Kaori Ozaki Ryo Akasaka Akira Teramoto 《Polymer Bulletin》2011,67(8):1455-1462
Emulsion polymerizations of several vinyl monomers, styrene, methyl methacrylate, butyl methacrylate, butyl acrylate, and vinyl acetate, in water using alkali–hydrolysable cationic surfactants with a betaine ester group (1-alkoxycarbonylmethyl)trimethylammonium chlorides, as emulsifiers were carried out and properties of the resulting latices and the polymers recovered by hydrolysis and salting out were investigated. There were little influences of the surfactants and monomers used here on the polymerizations, forming stable and monodisperse latices with a mean diameter of ca. 70 nm and giving a high molecular weight of polymers at high yields. All polymers were precipitated and recovered by adding a small amount of sodium hydroxide into the latex solutions contained little amount of ionic species. Solvent-cast films of the polymers were found to have surfaces as hydrophobic as those for the corresponding pure polymers prepared by bulk polymerization. 相似文献
94.
Avidin-containing polyelectrolyte microcapsules were prepared by a layer-by-layer deposition technique and uptake and release of biotin-labelled fluorescein (b-FITC) was studied. The polyelectrolyte microcapsules were prepared by coating the surface of calcium carbonate (CaCO3) microparticles containing avidin-poly(styrene sulfonate) (PSS) conjugate, followed by dissolution of CaCO3 core in an ethylenediaminetetraacetic acid solution. Release of avidin from the microcapsules was markedly suppressed due to formation of a high molecular weight of avidin-PSS conjugate in the microcapsules. The uptake of b-FITC into the microcapsules was highly enhanced through a strong binding of b-FITC to avidin, as compared to the uptake into avidin-free microcapsules. Release of b-FITC from the microcapsules was accelerated upon addition of biotin, 2-iminobiotin, or lipoic acid in the solution due to the competitive binding of the additives to the binding site of avidin. 相似文献
95.
Ichiro Fujii Shin Ariizumi Shintaro Ueno Chikako Moriyoshi Yoshihiro Kuroiwa Satoshi Wada 《Ceramics International》2018,44(9):10657-10662
We fabricated xBaTiO3 (BT)/(1-x)[BaTiO3-Bi(Mg1/2Ti1/2)O3-BiFeO3] (BT-BMT-BF)?+?0.1?wt%MnCO3 composites by spark plasma sintering and investigated the effect of BT content x, BT powder size, and BT-BMT-BF composition on piezoelectric properties. For xBT/(1-x)(0.3BT-0.1BMT-0.6BF) +?0.1?wt%MnCO3 (x?=?0–0.75) composites with a 0.5-µm BT powder, the dielectric constant was increased with x, and the relative density was decreased at x?=?0.67 and 0.75, creating optimum BT content of x?=?0.50 with a piezoelectric constant d33 of 107?pC/N. When a larger 1.5-µm BT powder was utilized for the composite with x?=?0.50, the d33 value increased to 150?pC/N due to the grain size effect of the BT grains. To compensate for a compositional change from the optimum 0.3BT-0.1BMT-0.6BF due to partial diffusion between the BT and 0.3BT-0.1BMT-0.6BF grains, a 0.5BT/0.5(0.275BT-0.1BMT-0.625BF)?+?0.1?wt%MnCO3 composite with the 1.5-µm BT powder was fabricated. We obtained an increased d33 value of 166?pC/N. These results provided a useful composite design to enhance the piezoelectric properties. 相似文献
96.
Taro Shimonosono Yoshihiro Hirata Mubin Changgan Syohei Kamei Rina Tokaiya Soichiro Sameshima Toshifumi Yoshidome Katsuhiko Yamaji 《Ceramics International》2018,44(8):8904-8912
This paper reports the performance of porous Gd-doped ceria (GDC) electrochemical cells with Co metal in both electrodes (cell No. 1) and with Ni metal in the cathode and Co metal in the anode (cell No. 2) for CO2 decomposition, CH4 decomposition, and the dry reforming reaction of a biogas with CO2 gas (CH4 + CO2 → 2H2 + 2CO) or with O2 gas in air (3CH4 +?1.875CO2 +?1.314O2 → 6H2 +?4.875CO +?0.7515O2). GDC cell No. 1 produced H2 gas at formation rates of 0.055 and 0.33?mL-H2/(min?m2-electrode) per 1?mL-supplied gas/(min?m2-electrode) at 600?°C and 800?°C, respectively, by the reforming of the biogas with CO2 gas. Similarly, cell No. 2 produced H2 gas at formation rates of 0.40?mL-H2/(min?m2) per 1?mL-supplied gas/(min?m2) at 800?°C from a mixture of biogas and CO2 gas. The dry reforming of a real biogas with CO2 or O2 gas at 800?°C proceeded thermodynamically over the Co or Ni metal catalyst in the cathode of the porous GDC cell. Faraday's law controlled the dry reforming rate of the biogas at 600?°C in cell No. 2. This paper also clarifies the influence of carbon deposition, which originates from CH4 pyrolysis (CH4 → C + 2H2) and disproportionation of CO gas (2CO → C + CO2), on the cell performance during dry reforming. The dry reforming of a biogas with O2 molecules from air exhibits high durability because of the oxidation of the deposited carbon by supplied air. 相似文献
97.
98.
Norihito Mayama Hiroyuki Yoshida Tatsuo Iwata Kaoru Sasakawa Atsushi Suzuki Yuya Hanaoka Yoshihiro Morita Akito Kuroda Masanori Owari 《Diamond and Related Materials》2010,19(7-9):946-949
In this study, we report the characterization of carbonaceous films deposited on metal substrates by liquid-phase electrodeposition in methanol. The characterization of carbonaceous films by electrodeposition was examined by means of Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), electron energy loss spectroscopy (EELS), secondary ion mass spectrometry (SIMS), atom probe (AP) and high resolution-elastic recoil detection analysis (HR-ERDA). From these results, it was found that the films deposited on the metal substrates were composed of the sp2 and sp3 carbon contents, of which the ratio was about 7:3. Furthermore, the films by electrodeposition contained much hydrogen. The hydrogen contents in the surface were about 60 at.% and those in the subsurface were a few 10 at.%. 相似文献
99.
Taeko Izumi Yoshihiro Yagimuma Masanori Haga 《Journal of the American Oil Chemists' Society》1997,74(7):875-878
Enyzmatic amidation of the primary amines β-alanine ethyl ester and 3-aminopropionitrile with methyl laurate by means of immobilized
lipase (Candida antarctica lipase, CAL) resulted in the formation in good yield of N-lauroyl-β-alanine ethyl ester and 3-(N-lauroylamino)-propionitrile, respectively. When 3-amino-propionitrile was used as substrate, diisopropyl ether was a suitable
solvent. Changing the reaction temperature (12–80°C) did not affect the yields, and room temperature was a suitable temperature
for this reaction. In the investigation of reaction conditions, the use of equimolar amounts (5 mmol) of substrate and ester,
along with 0.5 g of CAL, in diisopropyl ether gave the best yield (99.3%) after 24 h of incubation at 24°C. The enzyme activity
in the amidation reaction did not decrease even after six uses. With β-alanine ethyl ester hydrochloride as substrate, diisopropyl
ether was unsuited as a solvent owing to the low solubility of the substrate in this solvent.
In this reaction, the best yield (82.0%) was attained by using dioxane as solvent. CAL achieved higher extents of amide synthesis
with long-chain than with short-chain ester substrates. The enzyme accepted only nonbulky primary amines as substrates. 相似文献
100.
In this article, a genetic algorithm is applied to an optimization problem of material composition for a plate of step-formed functionally graded materials. The step-formed functionally graded plate is analyzed as a laminated composite plate made of numerous layers with homogeneous and different isotropic material properties. First, the onedimensional transient temperature distribution for a laminated plate is analyzed theoret ically. In addition, the thermal stress components for such an infinitely long plate are formulated under the mechanical condition of being traction-free. As a numerical example, a plate composed of zirconium oxide and titanium alloy is considered. In addition, for the optimization problem of minimizing the thermal stress distribution, the numerical calculations are made using a genetic algorithm without supposing a distribution function of material composition and the optimal material composition of each layer is determined taking into account the effect of the temperature dependency of material properties. Furthermore, the results obtained when a distribution function isn't specified and the results found when a distribution function is specified are compared. 相似文献