查询词典 grating

The main works include: In this thesis, we use Finite Difference Time Domain method to study the relationship between diffraction efficiency, angular dispersion and grating constant, to discuss how the grating figure influence the diffraction efficiency, and to research the frequency spectrum characteristic.

主要工作包括：本文分别在垂直入射和自准直入射（光垂直于光栅刻槽面入射）情况下，采用时域有限差分方法，利用商业数值计算软件OptiFDTD对二维闪耀光栅进行了矢量电磁场数值计算，研究了光栅的衍射效率和角色散随光栅常数的变化情况，研究了光栅形状对光栅衍射效率的影响，还讨论了各种光栅的频谱特性。

Based on the temperature-dependent complex dielectric constant of Indium Antimonide, an InSb-dielectric-InSb plasmonic waveguide structure with the grating is proposed. At the frequency of 1 THz, a directional beam is obtained, and its radiation direction can be controlled by changing the temperature difference between the grating structures on each side.

本文根据锑化铟材料在THz波段下复介电常数对温度的响应特性，采用了带有光栅的锑化铟-介质-锑化铟的表面等离子体波导结构，实现了1THz频率光束的准直出射，并能够通过调整结构两侧光栅的温度差来控制出射光束的角度。

After analyzing and processing the grating reticle image collected by CCD, the mapping coefficient can be accurately calculated from grid size to pixels. Comparing the fore-and-aft two grating reticle images after the worktable moved. Adopting phase difference ratio arithmetic based on Lissajous figures,the phase difference of two images will be figured out. The displacement of the worktable can be further calculated by the mapping coefficient.

调整光路使CCD获取清晰的光栅图像，对图像进行分析处理，计算出栅距与像素之间的映射关系，再对工作台移动前后的光栅图像进行对比，采用基于李萨如图的相位差比率算法获取它们的像素位置差，从而计算出工作台的实际运行位移。

Because the change of grating period caused by the asymmetrical rotation of two beams is limited to 5×10-4 nm at a tunability of the Bragg wavelength of ~100 nm, the tilt of grating caused by the rotation of the biprism can be ignorable.

因为在~100 nm范围内两光束的非对称旋转对光栅周期的改变是5×10-4 nm，双棱镜引入的光栅的闪耀可忽略。

The research on large chirped fiber Bragg grating is an important part of researches about the fiber grating devices.

大啁啾光纤光栅的研究是光纤光栅器件研究中的一个重要组成部分。

It can get the three-dimensional profile of the object surface effectively. Because of the cragginess of the three-dimensional surface when sine grating is projected the image of the sine grating is modulated and the modulated image is taken by a CCD camera with an angel compared to projecting direction. After the phase shift measuring method, the phase is gotten. Because the phase is calculated by the phase shift measuring ranges from –π to +π it isn't continuous. The phase unwrapping is necessary to recover the continuous phase about the object shape.

这种方法采用结构光照明，将正弦光栅图像投影到被测物体表面，用与投影方向成一定角度的CCD摄像机获取受物体表面面形调制的变形光栅像，根据数字相移算法计算出相位分布，由于从相移计算的相位被截断在反三角函数的主值范围内，因而是不连续的，必须通过相位展开恢复出连续相位分布，由相位－高度关系最终求出物体轮廓的三维数据信息。

Because of the cragginess of the 3-D surface, the distortion stripes appear when the common rectangular grating or sine grating is projected onto the object surface, which includes information about the 3-D surface profilometry. The images including distortion stripes are taken by CCD camera. The 2-D stripes information is got after processing these images. On the basis of mathematic reconstruction model and arithmetic, the 3-D surface profilometry data are gotten.

用普通白光将矩形光栅或者正弦光栅投影于被测物体表面上，由于物体外形凹凸等几何形状变化而在物体表面产生畸变条纹，这些畸变条纹就包含了物体表面形状的三维信息，由CCD摄像头摄取这些畸变条纹信息，对这些图像进行相应的处理，得到有关条纹中心线的二维信息，然后再根据相应的数学转换模型和重构算法对物体的轮廓进行重构，就可以得到被测物体表面的三维外形数据信息。

Because of the cragginess of the 3-Dsurface, the distortion stripes appear when the common rectangular grating or sine grating is projected onto the object surface, which includes information about the 3-Dsurface profilometry. The images including distortion stripes are taken by CCD camera. The 2-D stripes information is got after processing these images. On the basis of mathematic reconstruction model and arithmetic , the 3-D surface profilometry data are gotten.

用普通白光将矩形光栅或者正弦光栅投影于被测物体表面上，由于物体外形凹凸等几何形状变化而在物体表面产生畸变条纹，这些畸变条纹就包含了物体表面形状的三维信息，由CCD摄像头摄取这些畸变条纹信息，对这些图像进行相应的处理，得到有关条纹中心线的二维信息，然后再根据相应的数学转换模型和重构算法对物体的轮廓进行重构，就可以得到被测物体表面的三维外形数据信息。

It is suggested that for the diffraction efficiency optimization of the holographic grating recorded by plane and cylindrical waves the recording cylindrical wave and the geometrical dimension of the grating should be carefully designed according to the request.

在平面波与柱面波干涉形成全息透镜的设计中，为了获得最优的衍射效率，应当根据要求合理地选择记录所用柱面波和设计光栅的几何尺寸。

It is shown that, with the increase of the horizontal direction size of the grating, the diffraction efficiency of holographic grating increases.

结果表明，随着光栅横向尺寸的增加，光栅的衍射效率也逐渐增加。

Article 144 The Government of the Hong Kong Special Administrative Region shall maintain the policy previously practised in Hong Kong in respect of subventions for non-governmental organizations in fields such as education, medicine and health, culture, art, recreation, sports, social welfare and social

第一百四十四条香港特别行政区政府保持原在香港实行的对教育、医疗卫生、文化、艺术、康乐、体育、社会福利、社会工作等方面的民间团体机构的资助政策。原在香港各资助机构任职的人员均可根据原有制度继续受聘。

Small wonder, then, that the Chinese spend more in the shop than any other group of foreign visitors do .

这样的小惊喜，使中国顾客比任何国家的人消费得更多。