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Remziye Güzel Haslet Ekşi Zafer Üstündağ Ali Osman Solak 《Surface and interface analysis : SIA》2013,45(13):1821-1829
In this study, 4‐thiophenol modified glassy carbon electrode was prepared by the reduction of 4‐diazothiophenol tetrafluoroborate salt. Silver nanoparticles were attached to the thiophenol modified surface to prepare a thiophenol‐silver nanoparticle composite film. 4‐Aminothiopenol molecules were deposited by self‐assembling technique to form multi‐layered nanofilms of TP/SNP/PhNH2 on glassy carbon substrate. These surfaces were characterized by cyclic voltammetry, electrochemical impedance spectroscopy, X‐ray photoelectron spectroscopy, reflectance‐absorption infrared spectroscopy, and ellipsometry at each multilayer film growth process. Atomic force microscopic images of GC/TP/SNP/PhNH2 surfaces were also acquired. The characterization methods show that the amine group containing surface permits the subsequent modification by a variety of coupling reactions for the immobilization of more complex systems. An application of the electrode modification for the determination of uric acid with a significantly lower detection limit is described. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
84.
蓝宝石作为五大名贵宝石之一,经济价值极高,其中“皇家蓝”、“矢车菊蓝”最为昂贵。而水热法可合成出颜色与“皇家蓝”色极为相似的蓝宝石,且合成出的晶体较大,可通过切磨加工获得内部纯净的样品,仅凭外观及常规方法难以鉴别。选取了7颗水热法合成蓝色蓝宝石为实验对象,采用LA-ICP-MS、拉曼光谱仪、红外光谱仪、紫外-可见分光光度计和三维荧光光谱仪,对其化学成分、谱学特征进行研究,并与外观极为相似的天然蓝宝石、焰熔法合成蓝宝石进行对比分析。分析表明,水热法合成蓝宝石总体成分较为单一,而天然蓝宝石则含有丰富的微量元素。三种样品拉曼光谱均呈现典型的刚玉振动模式,显示A1g和Eg振动模的拉曼峰。在红外光谱的指纹区,三种样品的吸收峰均无明显差别,与拉曼光谱的结果耦合。但在官能团区3 000~4 000 cm-1波数范围,水热法合成蓝宝石存在由含水矿物包裹体产生的羟基振动峰,而天然蓝宝石和焰熔法合成蓝宝石未显示此特征。紫外-可见光谱表明三种样品均为Fe2+-Ti4+对致色,但水热法与焰熔法合成蓝宝... 相似文献
85.
以聚二甲基硅氧烷(PDMS)改性环氧树脂(HYSZ)为粘合剂,Sm2O3为功能颜料,纳米SiO2为微纳结构改性剂,制备得到了一种同时具有良好疏水性能和附着力的近红外吸收涂层。系统分析了PDMS和HYSZ质量比、邻苯二甲酸二辛酯(DOP)添加量、总填料添加量、 Sm2O3和纳米SiO2质量比对涂层性能的影响。结果表明:PDMS改性可明显降低涂层的表面能,从而使涂层的疏水性得到明显增强。利用DOP强化涂层韧性和微观搭桥作用可增强涂层整体性,从而可明显提高涂层的附着力和近红外吸收性能。涂层的表面粗糙度可随总填料添加量的增加而明显升高,进而可使涂层表现出更优的疏水性能。当涂层中PDMS和HYSZ质量比、 DOP添加量、总填料添加量、 Sm2O3和纳米SiO2质量比分别为1∶9, 20%, 50%和5.5∶4.5时,涂层同时具有良好的近红外低反射率(59.1%)、疏水性能(水接触角为137°)及附着力... 相似文献
86.
Numerical studies of the coupled Einstein‐Klein‐Gordon system have recently revealed that confined scalar fields generically collapse to form caged black holes. In the light of this finding, we analytically study the characteristic resonance spectra of the confined scalar fields in rotating linear dilaton black hole geometry. Confining mirrors (cage) are assumed to be placed in the near‐horizon region of a caged rotating linear dilaton black hole ( is the radius of the cage and r2 represents the event horizon). The radial part of the Klein‐Gordon equation is written as a Schrödinger‐like wave equation, which reduces to a Bessel differential equation around the event horizon. Using analytical tools and proper boundary conditions, we obtain the boxed‐quasinormal mode frequencies of the caged rotating linear dilaton black hole. Finally, we employ Maggiore's method, which evaluates the transition frequency in the adiabatic invariant quantity from the highly damped quasinormal modes, in order to investigate the entropy/area spectra of the rotating linear dilaton black hole. 相似文献
87.
A comprehensive set of spectra for the benzene cation and the perdeuterated benzene cation has been recorded with full rotational resolution using zero kinetic energy photoelectron spectroscopy (ZEKE) at high resolution (up to 0.2 cm?1), using a slow-rising extraction pulse. With different rovibronic levels in the S1 6l state as intermediate resonance, the rotational transitions to the vibronic ground state of the cation have been recorded using two-colour, two-photon resonance enhanced multiphoton ionization. A simple spectator model has been employed to simulate the intensities of the ZEKE transitions. By fitting the simulations to the recorded spectra, improved values for the rotational constants and the Coriolis coupling parameters of benzene and perdeuterated benzene have been obtained. The CC and CH bond lengths of the cation have been deduced. The spectator model is shown to be reliable despite the fact that no specific allowance is made for the effect of final state interactions on the signal intensity. 相似文献
88.
In this Letter, the dynamic plane elasticity problems of 2D quasicrystals is considered. By use of the Fourier transform and matrix transformations the system is reduced to uncoupled ordinary differential equations. Fourier images of Green's functions for dynamic plane elasticity problems of 2D dodecagonal, pentagonal and decagonal quasicrystals are obtained explicitly by the suggested method. 相似文献
89.
Kheir-Eddine Boudjemaa Mourad Guenouche Sami R. Zouzou 《General Relativity and Gravitation》2011,43(6):1707-1731
We compute the time delay of strong lensing in the framework of the Einstein-Straus solution in presence of a cosmological
constant and restrict ourselves to the case of a spatially flat universe. The calculations are done to first order in the
ratio of Schwarzschild radius to peri-lens. We apply our results to the lensed quasar SDSS J1004+4112. Our predictions for
the time delay between the images C and D of the quasar range from 6 to 13 years and are compatible with the experimental
lower bound. 相似文献
90.
Soraa Bouattour Wannes Kallel Ana Maria Botelho do Rego L.F. Vieira Ferreira I. Ferreira Machado Sami Boufi 《应用有机金属化学》2010,24(10):692-699
This work reports on the synthesis of Li‐doped TiO2 nanoparticles using the sol–gel process and solid‐state sintering, and investigates their potential use as a photocatalyst for degradation under sunlight excitation of different organic model compounds in aqueous solution. The structure of the nanocrystals was examined by X‐ray diffraction, UV‐vis ground state diffuse reflectance absorption spectra and X‐ray photoelectron emission spectroscopy. Results showed that samples prepared by sol–gel process and calcined at 400 °C are composed of a mixture of anatase and rutile phases, in contrast to the one prepared by solid‐state sintering, which exhibits an anatase phase with Li being involved in a spinel phase. The photocatalytic degradation of aqueous solutions of different aromatic compounds was successfully achieved under sunlight excitation in presence of Li‐doped TiO2 prepared via sol–gel process. It was shown that the calcination temperature and the preparation mode greatly affect the photocatalytic efficiency. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献