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51.
Namsin Park Takeyuki Shiraishi Kazuyoshi Kamisugi Yoshitaka Hara Keita Iizuka Takashi Kado Shuzi Hayase 《Journal of Applied Electrochemistry》2008,38(3):371-375
A direct ethanol fuel cell (DEFC), which is less prone to ethanol crossover, is reported. The cell consists of PtRu/C catalyst as the anode, Nafion® 117 membrane, and Ni–Co–Fe (NCF) composite catalyst as the cathode. The NCF catalyst was synthesized by mixing Ni, Co, and Fe complexes into a polymer matrix (melamine-formaldehyde resins), followed by heating the mixture at 800 °C under inert atmosphere. TEM and EDX experiments suggest that the NCF catalyst has alloy structures of Ni, Co and Fe. The catalytic activity of the NCF catalyst for the oxygen reduction reaction (ORR) was compared with that of commercially available Pt/C (CAP) catalyst at different ethanol concentrations. The decrease in open circuit voltage (Voc) of the DEFC equipped with the NCF catalysts was less than that of CAP catalyst at higher ethanol concentrations. The NCF catalyst was less prone to ethanol oxidation at cathode even when ethanol crossover occurred through the Nafion®117 film, which prevents voltage drop at the cathode. However, the CAP catalyst did oxidize ethanol at the cathode and caused a decrease in voltage at higher ethanol concentrations. 相似文献
52.
中国政府率先开始了手机充电器的标准化,其目的是让用户更换手机终端后可继续使用原来的充电器,从而通过削减废弃物达到保护环境的目的。 相似文献
53.
R Ikeda T Nagao H Okabe Y Nakano H Matsunaga M Katano M Mori 《Canadian Metallurgical Quarterly》1998,46(5):875-878
The constituents in the fruit of Anthriscus sylvestris Hoffm. were investigated, and four lignans [deoxypodophyllotoxin, morelensin, (-)-deoxypodorhizone, and (-)-hinokinin], one phenylpropanoid [1-(3',4'-dimethoxyphenyl)-1 xi-hydroxy-2-propene], two phenylpropanoid esters [3',4'-dimethoxycinnamyl (Z)-2-angeloyloxymethyl-2-butenoate and 3',4'-dimethoxycinnamyl (Z)-2-tigloyloxymethyl-2-butenoate], and one polyacetylenic compound (falcarindiol) were isolated. Their antiproliferative activity against MK-1, HeLa and B16F10 cell lines is reported. 相似文献
54.
Analysis of antireflection coatings using the FD-TD method with the PML absorbing boundary condition 总被引:1,自引:0,他引:1
A step-index optical waveguide with an antireflection coating is analyzed using the finite-difference time-domain (FD-TD) method combined with the perfectly matched layer absorbing boundary condition (PML-ABC). It is demonstrated that the numerical simulations having a dynamic range over that for the Mur absorbing boundary condition can be obtained for a single-layer coating. The analysis of a double-layer coating reveals the transient behavior of reflected fields. 相似文献
55.
Yasuro Ikuma Takashi Shigemura Takashi Hirose 《Journal of the American Ceramic Society》1996,79(10):2533-2538
Anatase-TiO2 cylindrical pellets were microwave sintered and partially transformed to rutile-TiO2 .The rutile concentration profile was determined as a function of location within the pellet. The rutile distribution in the microwavesintered pellets was different from that in pellets sintered by conventional fast firing. Temperature profiles within the pellets were estimated using the irreversible nature of the anatase-rutile transformation. The estimated temperature profile within each pellet was not uniform. In the axial direction, maximum temperature occurred in the middle of the pellet. In the radial direction, maximum temperature occurred at 1 mm below the surface of the cylinder wall. Analysis of the temperature profile indicated that, although heat flow occurred in the microwave-sintered pellet, the temperature profile did not change during a microwave exposure of 5–90 min. 相似文献
56.
57.
K. Nakano S. Tomiya M. Ukita H. Yoshida S. Itoh E. Morita M. Ikeda A. Ishibashi 《Journal of Electronic Materials》1996,25(2):213-216
Using electroluminescence (EL) topography and transmission electron microscopy (TEM), we investigated the nonluminescent regions
which form while current is being injected into ZnMgSSe/ZnSSe/ZnCdSe-based blue light emitters. Small dark spots were observed
just after turn-on and spread out forming rough nonluminescent triangles in the <100> directions in the EL image of the active
region. TEM studies showed that the small dark spots are pre-existing stacking faults originating at the substrate/epitaxial
layer interface. The nonluminescent triangles were found to be a dense region of dislocation dipoles and dislocation loops.
Each dipole was aligned along two <110> directions in the {111} planes. The Burgers vectors were of the type a/2<011> inclined
at 45° to the (001) junction plane. 相似文献
58.
A side-chain liquid-crystalline polymer (LCP) was synthesized by the addition of the mesogenic monomer to poly(methyl siloxane) in presence of a Pt-catalyst. When an aqueous solution of 10wt% ethanol was permeated through a LCP membrane by pervaporation at various temperatures, the permeation rate increased with increasing temperature and drastically changed at glass-nematic (Tg) and nematic-isotropic (TNI) transition temperatures of the LCP membrane. The LCP membrane exhibited the waterpermselectivity in the glassy and liquid-crystalline states. The ethanol concentration in the permeate increased with increasing permeation temperature and the LCP membrane changed from the waterpermselectivity to the ethanol-permselectivity around TNI. These results suggested that the permselectivity was influenced by the change of the LCP membrane structure, that is, its state transformation. It was found that a balance of the orientation of mesogenic groups and flexibility of siloxane chains is very important for the permeability and selectivity. 相似文献
59.
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