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Influence of local environment on the intensity of the localized surface plasmon polariton of Ag nanoparticles 下载免费PDF全文
A combined Ag nanoparticle with an insulating or conductive
layer structure has been designed for molecular detection using
surface enhanced Raman scattering microscopy. Optical absorption
studies revealed localized surface plasmon resonance, which shows
regular red shift with increasing environmental dielectric
constant. With the combined structure of surface enhanced Raman
scattering substrates and rhodamine 6G as a test molecule, the
results in this paper show that the absorption has a linear
relationship with the local electromagnetic field for insulating
substrates, and the electrical property of the substrate has a
non-negligible effect on the intensity of the local electromagnetic
field and hence the Raman enhancement. 相似文献
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为研究低刚度胀圈型旋转密封环的接触状态和密封性能,以聚醚醚酮(PEEK)材料的无槽环和V形槽环两种密封环为研究对象,基于COMSOL有限元软件建立了旋转密封流固耦合模型,对密封状态进行了模拟分析,并在试验台上测试了密封环的摩擦转矩和漏率. 仿真结果表明:在载荷作用下,密封环的变形显著影响密封面接触压力和流体压力分布. 试验结果表明:由于槽区流体的静压承载作用,V形槽环的摩擦转矩比无槽环小40%左右,但由于端面开槽减小了局部径向密封宽度,V形槽环漏率比无槽环大10%左右. 另外,两种环的摩擦转矩随转速增加均没有下降趋势,说明在试验条件下密封面动压减摩效果不显著. 研究结果有助于进一步认识胀圈型旋转密封环的密封机理,指导新型密封环的设计. 相似文献
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Analysis of heating effect on the process of high deposition rate microcrystalline silicon 下载免费PDF全文
A possible heating effect on the process of high deposition rate microcrystalline silicon has been studied.It includes the discharge time-accumulating heating effect,discharge power,inter-electrode distance,and total gas flow rate induced heating effect.It is found that the heating effects mentioned above are in some ways quite similar to and in other ways very different from each other.However,all of them will directly or indirectly cause the increase of the substrate surface temperature during the process of depositing microcrystalline silicon thin films,which will affect the properties of the materials with increasing time.This phenomenon is very serious for the high deposition rate of microcrystalline silicon thin films because of the high input power and the relatively small inter-electrode distance needed.Through analysis of the heating effects occurring in the process of depositing microcrystalline silicon,it is proposed that the discharge power and the heating temperature should be as low as possible,and the total gas flow rate and the inter-electrode distance should be suitable so that device-grade high quality deposition rate microcrystalline silicon thin films can be fabricated. 相似文献
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Frequency-selective surface (FSS) is a two-dimensional periodic structure consisting of a dielectric substrate and the metal units (or apertures) arranged periodically on it. When manufacturing the substrate, its thickness and dielectric constant suffer process tolerances. This may induce the center frequency of the FSS to shift, and consequently influence its characteristics. In this paper, a bandpass FSS structure is designed. The units are the Jerusalem crosses arranged squarely. The mode-matching technique is used for simulation. The influence of the tolerances of the substrate's thickness and dielectric constant on the center frequency is analyzed. Results show that the tolerances of thickness and dielectric constant have different influences on the center frequency of the FSS. It is necessary to ensure the process tolerance of the dielectric constant in the design and manufacturing of the substrate in order to stabilize the center frequency. 相似文献
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Frequency-selective surface(FSS)is a two-dimensional periodic structure consisting of a dielectric substrate and the metal units(or apertures)arranged periodically on it.When manufacturing the substrate,its thickness and dielectric constant suffer process tolerances.This may induce the center frequency of the FSS to shift,and consequently influence its characteristics.In this paper,a bandpass FSS structure is designed.The units are the Jerusalem crosses arranged squarely.The mode-matching technique is used for simulation.The influence of the tolerances of the substrate's thickness and dielectric constant on the center frequency is analyzed.Results show that the tolerances of thickness and dielectric constant have different influences on the center frequency of the FSS.It is necessary to ensure the process tolerance of the dielectric constant in the design and manufacturing of the substrate in order to stabilize the center frequency. 相似文献
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Three-dimensional elasticity solutions for static bending of thick functionally graded plates are presented using a hybrid semi-analytical approach-the state-space based differential quadrature method (SSDQM). The plate is generally supported at four edges for which the two-way differential quadrature method is used to solve the in-plane variations of the stress and displacement fields numerically. An approximate laminate model (ALM) is exploited to reduce the inhomogeneous plate into a multi-layered laminate, thus applying the state space method to solve analytically in the thickness direction. Both the convergence properties of SSDQM and ALM are examined. The SSDQM is validated by comparing the numerical results with the exact solutions reported in the literature. As an example, the Mori-Tanaka model is used to predict the effective bulk and shear moduli. Effects of gradient index and aspect ratios on the bending behavior of functionally graded thick plates are investigated. 相似文献