181 resultados para adsorbed layers
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We have optimized the settings of evanescent wave imaging for the visualization of a protein adsorption layer. The enhancement of the evanescent wave at the interface brought by the incident angle, the polarized state of light beam as well as a gold layer is considered. In order to improve the image contrast of a protein monolayer in experiments, we have optimized three factors-the incident angle, the polarization of light beam, and the thickness of an introduced thin gold layer with a theoretical simulation.
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Thermal effects of the heat transfer at free surface (represented by Biot number) on the Rayleigh-Marangoni-Benard instability in a system of liquid-porous layers with top free surface are investigated numerically. The results indicate that this thermal effect can evidently lead to the mode transition of convection, which is overlooked in previous works. (C) 2010 Elsevier Ltd. All rights reserved.
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Solidification behavior and microstructural evolution of surface modified layers in plasma cladding technique are studied via numerical simulations. Both the coupling effect of temperature and solid volume fraction are considered in the proposed thermal analytical model, by which the transient temperature distributions are calculated and the shape of melting pool is determined. Furthermore, we perform microscopic thermal analysis on the nucleation and growth behaviors of ceramic hardening phases and dendrites, as well as the kinetics of related two-phase flow systems. By comparing with experimental observations, the evolution mechanisms of the morphology of Al2O3 ceramic hardening layer are explained. Based on the above results, a relationship among the scanning velocity of plasma stream, dendritic growth rate and the advancing speed of solid/liquid interface is found, and an energy criterion is proposed for predicting the pushing/engulfing transition of ceramic particles by grain growth fronts. (C) 2009 Elsevier B.V. All rights reserved.
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IEECAS SKLLQG
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A novel PEMFC catalytic layer was fabricated by a Nafion-pyrolyzed method, which demonstrated a high performance with a maximum power density of 0.82 W/cm(2) on an electrode prepared by this method. The effects of the heat-treatment temperature and Nation content in the catalyst layer on performance were studied.
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This review surveys the recent progress in the adsorbed stationary phases for capillary electrochromatography (CEC). Adsorption-based methods for preparation of stationary phase are novel approaches in CEC, which allow rapid and facile preparing stationary phases with desirable selectivity onto an open-tubular fused-silica capillary, a baresilica or ion-exchange packed column or a monolithic silica or polymer column. A variety of adsorbing agents have been developed as adsorbed stationary phases, including ionic long-chain surfactant, protein, peptide, amino acid, charged cyclodextrin (CD), basic compound, aliphatic ionene, and ion-exchange latex particle. The adsorbed stationary phases have been applied to separation of neutral, basic and acidic organic compounds, inorganic anions and enantiomers. They have also been applied to on-line sample concentration, fast separation and study of the competitive binding of enantiomers with protein.
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A series of cross-linkable aromatic amines has been synthesized by the multi-step synthetic rout. Full characterization of their structure by H-1 NMR-, IR- and mass spectrometry is presented. The synthesized materials were examined by various techniques including differential scanning calorimetry, thermogravimetry, UV and electron photoemission spectrometry.
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In this study. Nafion (R) 117 membrane is surface-modified with mesoporous silica layers through in situ surfactant-templated sol-gel reaction. The reaction makes use of tetraethyl orthosilicate (TEOS) under acidic condition via dip-coating technique on both sides. Scanning electron microscopy (SEM), Fourier transformation infrared (FTIR), and thermogravimetric analysis (TGA) are employed to characterize the resultant membranes. Proton conductivity and methanol permeability of the membranes are also studied.