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281.
282.
New parameters which separately take into account the effects of elastic anisotropy and phonon dispersion on the lattice specific
heat in the case of fcc metals have been evaluated. A new graded mesh method which uses 162-direction approximation in (1/16)
part of the Brillouin zone has been developed to evaluate the two new parameters. 相似文献
283.
We have measured the permeability of rhodamine-6G across Cx43 hemichannels reconstituted on a pipette tip. Cx43 hemichannels
were overexpressed in Sf9 cells, and affinity-purified. The hemichannels were reconstituted in a lipid bilayer on a pipette
tip by the tip-dip method. R6G in the pipette permeated across the channels into the bath. The permeability of R6G was quantified
by measuring R6G concentration in the bath after several hours by surface enhanced Raman spectroscopy (SERS) with 100 nm silver
colloid particles. The ratio of the permeability of dye to salt, as extracted by this combined electrical-SERS technique,
is compatible with similar ratios for other dyes across whole gap junction channels. The results for the permeability ratio
were further compared to fluorescence measurements. The novel combination of patch and SERS techniques can be extended to
quantifying the transport of biologically significant non-fluorescent molecules, such as cAMP and IP3, across 1 nm sized pores,
such as the gap junction channel. 相似文献
284.
R. M. Lazorenko-Manevich 《Russian Journal of Electrochemistry》2005,41(8):799-831
A contemporary review of research concerning the mechanism of surface enhanced Raman scattering (SERS) is presented and it is stated that this problem is yet to be solved. The necessity to yet once again analyze some of the familiar experimental observations and the deep-rooted beliefs and revise quantitative evaluations of SERS enhancement via major mechanisms (electromagnetic and chemical) with allowance made for most important experimental characteristics of SERS is substantiated. The characteristics are enumerated and the role they play in the above evaluations is sketched. Attention is focused mainly on electrochemical aspects of SERS problem, which to a large extent define the content and salient features of SERS and provide basic experimental justification for the so-called adatom hypothesis.__________Translated from Elektrokhimiya, Vol. 41, No. 8, 2005, pp. 899–935.Original Russian Text Copyright © 2005 by Lazorenko-Manevich.In memory of Vladislav Vladimirovich Marinyuk 相似文献
285.
足球烯分子三阶非线性光学性质的研究 总被引:1,自引:0,他引:1
报道了有关足球烯分子甲苯溶液中简并四波混频实验.测量出足球烯C_(70)分子和C_(60)分子的三阶超极化率张量y_(1111)分量分别为1.2×10~(-30)esu和4.0×10~(-31)esu.对应于固体样品的三阶非线性光学系数X_(1111)分量分别是2.5×10~(-8)esu和8.5×10~(-9)esu.此结果表明了足球烯分子是现有的非线性光学材料中具有较大三阶非共振电子极化率材料之一.文中还利用自由电子模型解释了非线性光学极化率的起源. 相似文献
286.
One vision of clean energy for the future is to produce hydrogen from coal in an ultra-clean plant. The conventional route
consists of reacting the coal gasification product (after removal of trace impurities) with steam in a water gas shift (WGS)
reactor to convert CO to CO2 and H2, followed by purification of the effluent gas in a pressure swing adsorption (PSA) unit to produce a high purity hydrogen
product. PSA processes can also be designed to produce a CO2 by-product at ambient pressure. This work proposes a novel concept called “Thermal Swing Sorption Enhanced Reaction (TSSER)”
which simultaneously carries out the WGS reaction and the removal of CO2 from the reaction zone by using a CO2 chemisorbent in a single unit operation. The concept directly produces a fuel-cell grade H2 and compressed CO2 as a by-product gas. Removal of CO2 from the reaction zone circumvents the equilibrium limitations of the reversible WGS reaction and enhances its forward rate
of reaction. Recently measured sorption-desorption characteristics of two novel, reversible CO2 chemisorbents (K2CO3 promoted hydrotalcite and Na2O promoted alumina) are reviewed and the simulated performance of the proposed TSSER concept using the promoted hydrotalcite
as the chemisorbent is reported. 相似文献
287.
288.
半胱氨酸在银基底表面吸附机理的拉曼光谱研究 总被引:5,自引:2,他引:3
以具有表面增强拉曼散射 (SERS)活性的银镜为基底 ,将半胱氨酸组装到银基底表面 ;主要通过调整氨基酸溶液的pH值控制该组装过程。利用表面增强拉曼散射光谱对半胱氨酸小分子在银基底表面的吸附方式、作用机理进行了详细的探讨和研究。结果表明 ,只有当溶液的pH值接近或高于等电点时 ,半胱氨酸分子才能以 -COO- Ag+形式被有效组装到银基底的表面 ,形成表面带有自由疏基 (-SH)的半胱氨酸单分子膜 ,从而为硒代环糊精以 -S-Se-键形式组装到上述组装体系的表面提供了可能。本文的研究将为利用分子光谱探索含硒酶活性机理和进一步提高酶活性奠定基础。 相似文献
289.
290.
四频激光陀螺和频与温度关系的研究 总被引:5,自引:1,他引:4
研究了四频激光陀螺和频与温度之间的关系。通过静态和动态实验 ,证明了和频与温度的线性关系 ,并得到了拟合直线表达式。结果表明 ,和频与温度具有较好的线性关系 ,和频可作为温度测量的计量 ,而且具有较好的重复性。由于测量频率的精度较高 ,故由和频测量温度具有很高的分辨率。 相似文献