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91.
Electrochemical supercapacitive (ES) properties of liquid-phase synthesized mesoporous (pore size distribution centered ∼12 nm) and of 120 m2/g surface area nickel hydroxide film electrodes onto tin-doped indium oxide substrate are discussed. The amounts of inner and outer charges are calculated to investigate the contribution of mesoporous structure on charge storage where relatively higher contribution of inner charge infers good ion diffusion into matrix of nickel hydroxide. Effect of different electrolytes, electrolyte concentrations, deposit mass and scan rates on the current-voltage profile in terms of the shape and enclosed area is investigated. Specific capacitance of ∼85 F/g at a constant current density of 0.03 A/g is obtained from the discharge curve. 相似文献
92.
LiFePO4 nanocrystals were synthesized at a very low temperature of 170°C using carbon nanoparticles by a solvothermal process in
a polyol medium, namely diethylene glycol without any heat treatment as a post procedure. The powder X-ray diffraction pattern
of the LiFePO4 was indexed well to a pure orthorhombic system of olivine structure (space group: Pnma) with no undesirable impurities. The
LiFePO4 nanocrystals synthesized at low temperature exhibited mono-dispersed and carbon-mixed plate-type LiFePO4 nanoparticles with average length, width, and thickness of approximately 100 to 300 nm, 100 to 200 nm, and 50 nm, respectively.
It also appeared to reveal considerably enhanced electrochemical properties when compared to those of pristine LiFePO4. These observed results clearly indicate the effect of carbon in improving the reactivity and synthesis of LiFePO4 nanoparticles at a significantly lower temperature. 相似文献
93.
You KJ Ham HG Lee HJ Lang Y Im C Koh CS Kim MY Shin HC Shin HC 《IEEE transactions on bio-medical engineering》2011,58(5):1208-1215
This paper presents a novel method for inferring the odor based on neural activities observed from rats' main olfactory bulbs. Multichannel extracellular single unit recordings were done by microwire electrodes (tungsten, 50 μm, 32 channels) implanted in the mitral/tufted cell layers of the main olfactory bulb of anesthetized rats to obtain neural responses to various odors. Neural response as a key feature was measured by subtraction of neural firing rate before stimulus from after. For odor inference, we have developed a decoding method based on the maximum likelihood estimation. The results have shown that the average decoding accuracy is about 100.0%, 96.0%, 84.0%, and 100.0% with four rats, respectively. 相似文献
94.
Kyoung-Ho Kang Hyun-Sik Park Seok Cho Nam-Hyun Choi Sung-Won Bae Seung-Wook Lee Yeon-Sik Kim Ki-Yong Choi Won-Pil Baek Moo-Yong Kim 《Annals of Nuclear Energy》2011
Integral effect tests using the ATLAS facility were performed to obtain the thermal-hydraulic parameters such as dynamic and static pressures, local temperatures, and flow rates during a feedwater line break of a steam generator. The break of a feedwater line was simulated using a double rupture disc assembly in order to satisfy the requirements for the break opening time of around a few milliseconds. In the present study, estimated break opening time was less than 1.5 ms and broken areas were 48.1% and 93.4% of the feedwater line, respectively. The maximum dynamic pressures of about 1.57 bar were obtained inside of feedwater box that was closest to the break location of the feedwater line. After the break of the feedwater line, propagation of the pressure wave along the distance from the break location inside the steam generator was clearly and pertinently observed in all the tests. From a structural integrity point of view, however, the risk induced by this maximum dynamic load could be treated to be insignificant. 相似文献
95.
96.
Moon Hyeon Kim Kyung Ho Cho Chae-Ho Shin Seong-Eun Kang Sung-Won Ham 《Korean Journal of Chemical Engineering》2011,28(4):1139-1143
The catalytic activity of Cu-Mn mixed oxides with varying Cu/Mn ratios prepared by co-precipitation method was examined for
the total oxidation of propane. The nature and phase of the metal oxide species formed were characterized by various methods
such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), H2 temperature-programmed reduction (TPR) as well as BET surface area measurement. The co-precipitation method provides highly
interdispersed copper and manganese metallic elements forming Cu-Mn mixed oxide of spinel structure (Cu1.5 Mn1.5O4). Besides the spinel-type Cu-Mn mixed oxide, CuO or Mn2O3 phases could be formed depending on the Cu/Mn molar ratio of their precursors. The catalytic activity of Cu-Mn mixed oxide
catalyst for propane oxidation was much higher than those of single metal oxides of CuO and Mn2O3. The higher catalytic activity likely originates from a synergic effect of spinel-type Cu-Mn mixed oxide and CuO. The easier
reducibility and BET surface area seems to be partially responsible for the high activity of Cu-Mn mixed oxide for total oxidation
of propane. 相似文献
97.
ABSTRACT: Crystalline Co nanoparticles were hybridized with single-crystalline Bi nanowires simply by annealing Co-coated Bi nanowires at elevated temperatures. An initially near-amorphous Co film of 2-7 nm in thickness began to disrupt its morphology and to be locally transformed into crystallites in the early stage of annealing. The Co film became discontinuous after prolonged annealing, finally leading to isolated, crystalline Co nanoparticles of 8-27 nm in size. This process spontaneously proceeds to reduce the high surface tension and total energy of Co film. The annealing time required for Co nanoparticle formation decreased as annealing temperature increased, reflecting that this transformation occurs by the diffusional flow of Co atoms. The Co nanoparticle formation process was explained by a hole agglomeration and growth mechanism, which is similar to the model suggested by Brandon and Bradshaw, followed by the nanoparticle refinement. 相似文献
98.
Yensil Park Dong Wook Suh Kyoung Soon Choi Jae Soo Yoo Juyoung Ham Jong-Lam Lee Soo Young Kim 《Organic Electronics》2013,14(4):1021-1026
We report the effect of yellow Sr2SiO4:Eu2+ and green SrGa2S4:Eu2+ phosphors on the efficiency of organic photovoltaic (OPV) cells. Each phosphor was coated on the back side of indium tin oxide (ITO)/glass substrates by spin coating with poly(methyl methacrylate) (PMMA). The maximum absorption wavelength of the active layer in the OPV cells was ~512 nm. The emission peaks of Sr2SiO4:Eu2+ and SrGa2S4:Eu2+ were maximized at 552 nm and 534 nm, respectively. The short circuit current density (Jsc) and power conversion efficiency (PCE) of the OPV cells with Sr2SiO4:Eu2+ (8.55 mA/cm2 and 3.25%) and with SrGa2S4:Eu2+ (9.29 mA/cm2 and 3.3%) were higher than those of the control device without phosphor (7.605 mA/cm2 and 3.04%). We concluded that phosphor tuned the wavelength of the incident light to the absorption wavelength of the active layer, thus increasing the Jsc and PCE of the OPV cells. 相似文献
99.
Mei‐Yi Liao Cheng‐Ham Wu Ping‐Shan Lai Jiashing Yu Hong‐Ping Lin Tzu‐Ming Liu Chih‐Chia Huang 《Advanced functional materials》2013,23(16):2044-2051
The development of fluorescent iron oxide nanomaterials is highly desired for multimodal molecular imaging. Instead of incorporating fluorescent dyes on the surface of iron oxides, a ligand‐assisted synthesis approach is developed to allow near‐infrared (NIR) fluorescence in Fe3O4 nanostructures. Using a trimesic acid (TMA)/citrate‐mediated synthesis, fabricated Fe3O4 nanostructures can generate a NIR two‐photon florescence (TPF) peak around 700 nm under the excitation by a 1230‐nm femtosecond laser. By tailoring the absorption of Fe3O4 nanostructures toward NIR band, the NIR‐TPF efficiency can be greatly increased. Through internal etching, surface peeling, and ligand replacement, spectroscopic results validated that such resonantly enhanced NIR‐TPF is mediated by surface states with strong NIR‐IR absorption. This TPF signal evolution can be generalized to other iron oxide nanomaterials like magnetite nanoparticles and α‐Fe2O3 nanoplates. Using the developed fluorescent Fe3O4 nanostructures, it is demonstrated that their TPF and third harmonic generation (THG) contrast in the nonlinear optical microscopy of live cells. It is anticipated that the synthesized NIR photofunctional Fe3O4 will serve as a versatile platform for dual‐modality magnetic resonance imaging (MRI) as well as a magnet‐guided theranostic agent. 相似文献
100.
Bhagwat N. Pawar Dukho Ham T. Ganesh Ramphal Sharma Sung-Hwan Han 《Solar Energy Materials & Solar Cells》2009,93(4):524-527
A simple and economic chemical spray pyrolysis method is used to prepare transparent and conducting boron-doped zinc oxide (BnZnO) electrode having potential applications in dye-sensitized solar cells (DSSCs). The BnZnO electrodes were critically characterized for their structural, morphological and electrical properties. The BnZnO electrode with 2 at% boron doping showed average grain size of 20(±1) nm, surface roughness of 9 nm, ?95% transparency and resistivity of 4.5×10−3 Ω cm−1. Furthermore, doping concentration of boron could also be easily controlled for achieving desired properties. Using this electrode as a substrate in DSSCs, the solar-to-electrical conversion efficiency with N3 dye as a sensitizer was noted to be 1.53%. This work suggests that the BnZnO electrodes could be used as promising alternative to presently used indium- or fluorine-doped tin oxide as substrates. 相似文献