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951.
This paper presents a more detailed interaction of an electromagnetics light with a metallic surface-relief subwavelength grating utilizing the rigorous coupled-wave analysis. The focus of this work is the accurate modeling of undetermined aspects of diffraction patterns produced by binary metallic grating structures, specially gold grating. First-order diffraction efficiency for rectangular-groove gold grating with equal groove and ridge widths are presented for various wavelengths as a function of period, groove depth, polarization and angle of incidence. We also studied diffraction efficiency of both of TE and TM polarization modes against increasing of incident angle as well as TE polarization against increment of grating period. As a result, very low reflectivity at zero-order was found out for TE and TM polarizations at the pitch of Λ = 2λ. Having been studied diffraction efficiency of metallic surface-relief gratings, we also examined polarization-dependent efficiency of diffraction orders, for different groove depths. Simulation results have been completely presented. 相似文献
952.
Influence of roughness on the detection of mechanical characteristics of low-k film by the surface acoustic waves 下载免费PDF全文
The surface acoustic wave (SAW) technique is a precise and nondestructive method to detect the mechanical charac- teristics of the thin low dielectric constant (low-k) film by matching the theoretical dispersion curve with the experimental dispersion curve. In this paper, the influence of sample roughness on the precision of SAW mechanical detection is inves- tigated in detail. Random roughness values at the surface of low-k film and at the interface between this low-k film and the substrate are obtained by the Monte Carlo method. The dispersive characteristic of SAW on the layered structure with rough surface and rough interface is modeled by numerical simulation of finite element method. The Young's moduli of the Black DiamondTM samples with different roughness values are determined by SAWs in the experiment. The results show that the influence of sample roughness is very small when the root-mean-square (RMS) of roughness is smaller than 50 nm and correlation length is smaller than 20 μm. This study indicates that the SAW technique is reliable and precise in the nondestructive mechanical detection for low-k films. 相似文献
953.
高灵敏度的光纤光栅压强传感器 总被引:15,自引:0,他引:15
基于光纤布拉格光栅传感模型 ,提出了一种等强度梁与波纹管相结合的高灵敏度的光纤布拉格光栅压强传感器 ,推导了光纤布拉格光栅反射波中心波长相对偏移量与压强之间的解析关系式 ,从理论和实验上给出了压强灵敏度系数。该传感器的理论和实验压强灵敏度系数分别是 1.4 76× 10 -2 MPa-1、1.35× 10 -2 MPa-1,是裸光纤光栅的 74 5 5倍和 6 80 8倍 ,理论值与实验值吻合得很好。同时指出通过调节等强度梁和波纹管的参量 ,可以将该传感器的压强灵敏度系数做得很高 ,直至破坏了光纤布拉格光栅。 相似文献
954.
Porous silicon is widely studied in the field of photonics due to its interesting optical properties. In this work, we present theoretical and first experimental studies of a new kind of porous silicon photonic device based on optical surface wave. A theoretical analysis of the device is presented using plane-wave approximation. The porous silicon multilayered structures are realized using electrochemical etching of p+-type silicon. Morphological and optical characterizations of the realized structures are reported. 相似文献
955.
将化学共沉淀法合成的Co掺杂的Fe_3O_4(Co-Fe_3O_4)磁性粒子和化学氧化法合成的聚苯乙烯磺酸钠(PSS)掺杂的聚(3,4-乙撑二氧噻吩)(PEDOT-PSS)与聚乙烯醇(PVA)混合制备复合纺丝原液,然后经过湿法纺丝得到具有电、磁性能的PEDOT-PSS/Co-Fe_3O_4/PVA复合纤维.通过SEM、FTIR、XRD、TG、VSM以及电导率和机械性能的测试研究了不同牵伸倍率对复合纤维的结构和性能的影响.结果表明,随着牵伸倍率的增加,复合纤维的结晶性能、热稳定性能和机械性能都有所提升,其电导率则成倍增加,而其饱和磁化强度(M_s)则变化不大,约为1.7 A·m~2/kg.当牵伸倍数为4倍时,复合纤维的电导率可达到2.3 S/cm. 相似文献
956.
957.
T. R. Amanbaev 《Journal of Applied Mechanics and Technical Physics》2003,44(5):634-639
The gas flow in plane shock waves slipping along an impermeable surface with a rectangular cavity where solid disperse particles are suspended is considered numerically. The motion of the gas and particles (gas suspension) is modeled by equations of mechanics of multiphase media. Some laws of the behavior of the dusty cloud in the cavity are established for the case of wave interaction with the cavity. 相似文献
958.
959.
960.
Xiongfeng Yang 《Mathematical Methods in the Applied Sciences》2011,34(11):1366-1380
This paper studies the stability of the rarefaction wave for Navier–Stokes equations in the half‐line without any smallness condition. When the boundary value is given for velocity u∥x = 0 = u? and the initial data have the state (v+, u+) at x→ + ∞, if u?<u+, it is excepted that there exists a solution of Navier–Stokes equations in the half‐line, which behaves as a 2‐rarefaction wave as t→ + ∞. Matsumura–Nishihara have proved it for barotropic viscous flow (Quart. Appl. Math. 2000; 58:69–83). Here, we generalize it to the isentropic flow with more general pressure. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献