查询词典 x ray diffraction

Including clinical breast X-ray machine technology applications, digital breast X-ray machine performance testing and evaluation methods and projects, digital breast X-ray machine and traditional breast X-ray machine of distinction contrast, Finland Planmed high frequency of breast X-ray photography Clinical application, the new mammography X-ray machines and mammography in the diagnosis of the research topic.

包括乳腺X线机临床技术应用，数字乳腺X线机的性能测试方法及项目与评价，数字乳腺X线机与传统乳腺X线机的临床区别对比，芬兰Planmed型高频乳腺机X线摄影技术临床应用，新型钼靶X线机在乳腺摄影及诊断中的应用等研究课题。

In the second chapter, during the study of compound x-ray refractive lenses, diffraction function of compound lens is derived in the light of refraction and absorption effect and the design theory of X-ray is deduced using diffraction theory in connection with the characteristic of X-ray band.

在第二章X射线聚焦组合透镜的研究中，针对X射线波段的特性，综合考虑折射和吸收效应得出组合透镜的衍射屏函数，利用衍射理论推导出X射线聚焦组合透镜的设计理论并进行结构设计与微细加工制作技术研究。

Based on the relations of the diffraction field and the surface wave, which conclude diffraction factor and interference factor, some relations were conformed such as: the diffraction fringes spatial distribution versus surface wavelength, the fringes half angular width versus the numbers of surface wave covered by laser spots and incidence angle, diffraction intensity versus surface wave amplitude.

通过对衍射因子和干涉因子的分析，得到衍射条纹空间分布与表面波波长的关系、条纹的半角宽度与入射激光光斑覆盖表面波的个数和入射方向的关系、衍射光强度与表面波振幅的关系，并解释了条纹缺级现象。

The principle of the two dimensional acoustooptic Q switch is presented,the formulas of the diffraction efficiency and diffraction loss of the AO Q switch with normal Bragg diffraction is derived,the relationship between One dimensional and Two dimensional Bragg diffraction is analyzed.

描述了两维声光Q开关的基本原理，详细推导出正常布喇格衍射的两维声光Q开关衍射效率和衍射损耗的表达式，分析了两维布喇格衍射和一维布喇格衍射之间的关系，并给出了在驱动功率40W、光束直径5mm、光波长1。

The diffraction theory of Kirchhoff is applied to the four-pinhole aperture diffraction screens, the intensity, the zero-contour of the real and imaginary parts of complex amplitude and the phase distribution in deep Fresnel diffraction region are simulated, and it is found that the bright spots in interference field show central symmetry distribution. When the observation plane close to the diffraction screen, the zero-value points of light intensity can form line segment, on which the eccentricities of the light intensity isoline are close or equal to 1, the intensity changes very fast on both sides of the zero-line of light intensity.

利用基尔霍夫衍射理论计算了四圆孔径衍射屏在菲涅尔深区形成的的干涉光场的强度、零值线和相位的分布，发现干涉光场亮斑关于中心呈对称分布，在距离衍射屏较近的观察面上，光强值为的零点组成光强零值线段，该线段上光强等值线的离心率都接近或等于1，其两侧的光强值变化非常剧烈。

As well known, modern laser diffraction has widely used in engineering measurement but it mostly limited in Fraunhofer diffraction because there is simple function between the size to be measured and space of diffraction dark spots and there are no analytic algorithm for Fresnel diffraction.

现代激光技术提供了极为良好的相干光源，该光源在工程测量，特别是衍射测量中得到广泛应用。但在实际应用中，往往局限于夫琅和费衍射，因为夫琅和费衍射法暗斑间距与被测尺寸之间具有很简单的函数关系S-n/d，而菲涅尔衍射光强分布非常复杂，缺乏解析的计算方法。

Based on Matlab, simulation program of grating diffraction is complied. By changing adjustable parameters, computer simulations of white light interference and diffraction experiments (i. e., grating diffraction, single slit and double-slit diffraction, double-beam and multi-beam interference experiments) can be achieved.

基于Matlab软件编写出白光光栅衍射仿真程序，通过改变可调参数实现白光干涉、衍射实验（包括：光栅衍射、单缝及双缝衍射、双光束及多光束干涉等）的计算机仿真。

The phase constitution and structure of a partially stabilized Zirconia with yttria and magnesia have been investigated by means of electron diffraction, diffraction contrast image, X-ray diffraction and image simulation.

通过透射电子显微术、X射线衍射和电子计算机图像模拟等手段、对由Y〓O〓和MgO复合稳定的ZrO〓陶瓷—-PSZ的相组成和相结构进行了观察测定。在此基础上，对电子衍射谱中的漫散射现象进行了系统、细致的研究。

Results Compared high kV X-ray chest film with spiral CT,to simplex silicosis,X-ray films coincided with CT scans;to mixed silicosis,the effect of CT scans were better than X-ray's;to large nodule,coalesced progressive massive fibrosis,the detected ratio of CT scans were higher than X-ray chest films;to silicosis complication,for example,emphysema,pleural thickening,phthisic,mediastinal impairment lympy node etc,CT scans were more reliable than X-ray films,especially HRCT can earlier find silicotic nodule and fine structure of focus.Selective application of CT scan,had great diagnostic value in complicated silicosis and silco-tuberculosis and lung cancer complicated with silicosis etc.

结果 高千伏X线胸片与螺旋CT作对比，结果对单纯矽肺并发肺癌，CT片与X线胸片基本一致；对于复杂矽肺并发肺癌CT优于X线胸片；对于大结节、肺内进行性大块纤维化(progressive massive fibrosis，PMF)融合、空洞及钙化CT检出率明显高出胸片；对矽肺并发肺癌的合并其他如肺气肿、胸膜肥厚、结核、纵隔淋巴受累等CT均较胸片可靠；特别是HRCT能早期发现矽肺肿块样病灶中细微结构，选择性应用CT，对复杂矽肺并发肺癌合并结核等鉴别诊断有很大价值。

Knowledge of tungsten anode X-ray tube spectra is essential for X-ray dose control, X-ray image quality evaluation and dual-energy X-ray imaging etc. A model-based tungsten anode X-ray tube spectrum reconstruction method is presented in this paper.

X射线球管光谱信息是进行X射线曝光剂量控制、X射线成像质量评估、X射线双能量成像等必不可少的，为此本文提出一种基于模型的钨靶X射线球管光谱重建方法。

Salt is good, but if the salt becomes flat and tasteless, with what do you season it?

14：33 盐本是好的，盐若失了味，可用什么叫它再咸呢？

He reiterated that the PLA is an army of the people under the leadership of the Communist Party of China.

他重申，人民解放军是在中国共产党领导下的人民军队。