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排序方式: 共有21条查询结果,搜索用时 46 毫秒
1.
针对微操作工具在测试窗口内(X-Y平面)大范围移动时,采集到的模糊图像差异较大的问题,提出了一种新的不变量特征提取方法――规范化谱图像,将其应用于深度估计可提高系统的鲁棒性。同时,利用主成份分析方法可降低数据的维数并抑制噪声的影响,使得系统的实时性和精度得到较大改善。实验结果验证了上述方法的有效性。  相似文献   
2.
We demonstrate that the directionality of far-field second harmonic(SH) emission generated from individual gold nanosphere can be flexibly engineered by manipulating three-dimensional(3D) focal polarization orientation of the excitation field, which is explained by the coherent interference between SH dipolar and quadrupolar emission modes. The SH dipolar emission mode is independent of the polarization direction of the fundamental field whereas the evolution of the focal polarization orientation can dramatically modify the quadrupolar emission pattern. Therefore, the resultant SH emission pattern has a polarization-dependent behavior and side scattering almost perpendicular to the propagation direction of the incident light can be observed under a specific condition. Our findings provide a novel degree of freedom for all-optical control of directional nonlinear scattering from single nanoantenna, thereby opening new possibilities for future potential applications.  相似文献   
3.
An electromagnetically induced transparency (EIT) in metamaterial resonator with two bright modes and one dark mode at the terahertz (THz) band is numerically and experimentally demonstrated. Different from two kinds of the traditional passive modulations, our design can realize the passive modulation of EIT phenomenon by adding another bright mode resonator. Simulated and experimental results show that the transmission peak varies for incident THz waves with different polarization directions due to its asymmetric structure, which provides a novel way to realize high efficiency switch and modulation.  相似文献   
4.
合成了用于阳极电泳漆的阴离子丙烯酸树脂,研究了影响树脂电沉积效果和涂膜性能的因素,探讨了涂膜在高温和低温固化的实现途径.  相似文献   
5.
Based on the generalized Mie theory, refractive index sensing characteristics of single silver nanoparticle respectively illuminated by tightly focused linearly-polarized and radially-polarized light beams are investigated. The spectra for localized surface plasmon resonances (LSPR) under different dielectric environments demonstrate that distinct dipolar and quadrupolar resonances can be always observed for the case of radial polarization, while there is only strong dipolar resonance for the case of linear polarization. The dipolar mode has a higher sensitivity. However, the figure of merit (FOM) for the quadrupolar resonance is much higher than that for the dipolar resonance, because the quadrupolar resonance has a narrower width.  相似文献   
6.
王湘晖  谢灵峰  谭征兵 《中国涂料》2007,22(12):31-34,37
通过溶液自由基聚合合成了用于阴极电泳涂料的阳离子丙烯酸树脂,研究了影响树脂水溶性、电沉积效果和涂膜性能的因素,并详细阐述了在应用方面的研究。  相似文献   
7.
介绍了不同液晶材料在太赫兹(THz)波段的光学各向异性和外场调制特性。在此基础上,综述了几种基于液晶与人工电磁微结构相结合的THz功能器件,该器件可实现对THz波的调谐滤波、电磁诱导透明、相位调制以及偏振控制功能等;系统地分析了液晶与人工电磁微结构的相互作用机理、THz波长尺度下液晶的外场调控规律与表面相互作用。此外,还对THz液晶光子器件的研究发展趋势进行了展望。  相似文献   
8.
Using the vector diffraction theory and the phenomenological model, this paper investigates the second harmonic generation (SHG) of a single centrosymmetric nanosphere excited by focused doughnut beams (DBs) with different topological charges. The results show that strong backward SHG (BSHG) appears when the particle is excited by focused DBs with topological charges of . The backward second harmonic radiation can be caused by the depolarized effect of high numerical aperture (NA) objectives due to the strong longitudinal components.  相似文献   
9.
研制了一种新型LED阵列和相匹配的聚光透镜阵列构成的高亮度LED铁路信号机光学系统。进行了光学结构设计和理论计算,作了实验测试。测试结果表明,红、黄、绿、蓝和自信号机沿光轴中心光强分别大于2100、3900、2800、400和3200cd,均达到铁路信号机各项光学指标,可代替传统的以白炽灯为光源及有色玻璃螺纹聚光镜构成的铁路信号机光学系统,具有亮度高、节能和寿命长等优点。  相似文献   
10.
用滤波器提高共焦系统纵向分辨率的实验研究   总被引:1,自引:1,他引:0  
针对采用有限大小探测器的其焦显微系统,利用两区相位型滤波器提高系统的纵向分辨率。在实验上,采用1透射式液晶空间比例制器实脱了对共焦显微系统照明光场位相的动态调制,测量了探测针孔直径分别为5μm、10μm和15μm时,共焦显微系统纵向分辨率随滤波器参数的变化规律。实验结果说明,在探测器为有限大小的情况下,利用该滤波器可以使共焦显微系统的纵向分辨率提高17.8%。另外,从实验结果还可以看出,滤波器的性能受到探测针孔尺寸的影响。  相似文献   
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