查询词典 x ray diffraction

X-ray diffraction is one of the most common and efficient ways to measure a superlattice structure. This dissertation displays the detail results for characterization of Ge〓Si〓/Si superlattices by x-ray diffraction (including x-ray small angle diffraction and double crystal diffraction). It was found, when the growth temperature is lower, the intensities of xray small angle diffraction peaks are modulated by a periodical function, which indicates that both sets of interfaces of the superlattice is highly flat; when the growth temperature is higher, the diffraction peak intensities are simply decay with the increase of diffraction vector, which indicates that one set of interfaces is highly flat but another is not; when the growth temperature is very high, the diffraction peaks are reduced more rapidly, which indicates that both sets of interfaces are not ideal.

本文详细介绍了用X-射线衍射（包括X-射线小角衍射和双晶衍射）方法对Ge〓Si〓/Si超晶格结构特性测试的结果，尤其是发现，当Ge〓Si〓/Si超晶格的生长温度较低时，X-射线小角衍射谱峰的强度随着衍射波矢的增加而周期性调制，表明超晶格的两套界面都十分平整；当生长温度较高时，Ge〓Si〓Si超晶格的X-射线小角衍射谱峰的强度随着衍射波矢呈简单的衰减变化，对应于超晶格内有一套界面不平整的情况；当生长温度进一步提高时，X-射线小角衍射峰明显减少，表明超晶格内两套界面都不理想。

The camera length of electron diffraction in transmisson electron microscopy is one of the main technical parameters in designing electron microscope and the electron diffraction analysis to microcrystal sample. According to Bragg law, the formula of calculating TEM electron diffraction camera length is derived from the research on the ray path of electron diffraction images in TEM and the comparison on electron diffraction with ordinary electronic diffractometer. The difference of physical significance of electron diffraction camera length between TEM and ordinary electronic diffractometer is discussed.

透射式电子显微镜(Transmisson Electron Microcopy， TEM)中的电子衍射相机长度，是电子显微镜设计和对微晶体样品进行电子衍射分析的主要技术参数之一依据布拉格定律，经对TEM中电子衍射成像光路的探讨与研究，并通过TEM与普通电子衍射仪的电子衍射的对比分析，导出了TEM电子衍射相机长度的精确计算公式，阐述了TEM和普通电子衍射仪的电子衍射相机长度所表征的物理意义的区别。

The study about the flux and index of gamma-ray loud blazars show:(1)there is significant correlation between the luminosities in gamma-ray and VLBI radio energy band;(2)there are strong anticorrelarions among the observed indices of soft X-ray, hard X-ray and gamma-ray. For the FSRQs, the whole X-ray emission was contributed by synchrotron self-Compton emission, for the HBLs, the X-ray emission was dominated by synchrotron emission while the soft X-ray emission is dominated by synchrotron emission and the SSC emission dominate the hard X-ray energy band for LBLs;(3) there are strong radio-radio and radio-optical flux correlations for the quasar 3C 273. The higher frequency emission leads those in lower frequency. The multi-band complex indices strongly correlated with the high frequency flux which implies that the object is becoming bright when the energy spectrum is harden.

通过对γ噪Blazar天体的谱指数、流量的相关研究，发现（1）51个样本blazar的γ射线光度与VLBI光度之间存在显著相关；（2）软X、硬X以及γ波段的观测谱指数之间存在较强的反相关，对FSRQs，无论是硬X射线还是软X射线的辐射都是逆康普顿辐射的贡献，而对于HBLs来说，则是同步辐射的贡献，对LBLs，在软X射线波段以同步辐射贡献为主，在硬X射线能区以逆康普顿贡献为主；（3）3C 273的射电各个波段以及光学之间存在强相关，高频辐射一直领先低频辐射，3C 273的多波段复合谱指数和高频流量之间存在强的反相关，意味着当能谱变硬时对象变亮。

Measurement of gamma ray activities can be transformed to that of alpha ray and beta ray activities. When natural radionuclides are well distributed in materials, there is fixed interrelationship between alpha ray and beta ray activities in any part of a decorative material and alpha ray and beta ray surface activities.

同时，ICRP和IAEA都已明确我国《放射卫生防护基本标准》GB4792-1984对公众的剂量限值不适用于天然放射性，而我们的国家标准仍使用土壤的剂量转换因子和公众的年剂量限值来推导建筑材料的核素限量。

It is showed that in the X-ray diffraction patterns of the interlayer solid solution Ti3Si0.9Al0.3C1.93 and Ti3Si0.8Al0.4C1.93 bulk samples,which were in-situ reactively synthesized by hot-pressing the elemental Ti,Si,Al and C mixed powders,the diffraction peaks of [00L] crystal planes are very weak,there is only a small diffraction peak belonging to the [008],and the diffraction peaks belonging...

结果发现，用热压Ti、Si、Al和C混合粉末原位反应合成的Ti3Si0.9Al0.3C1.93和Ti3Si0.8Al0.4C1.93层间固溶体块体样品的X射线衍射谱中[00L]晶面的衍射峰极其微弱，只有[008]面有一个小的衍射峰，[002]、[004]和[006]面几乎没有衍射峰存在，而该块体样品的粉末的X射线衍射谱中所有[00L]晶面的衍射峰均存在。

The changes in phase structure and Curie temperature of the Sm2Fe17 compound after nitrogen absorption were studied by using X-ray diffraction, differential thermal/thermo-gravimetric analyzer and magnetic measurement. The results of X-ray diffraction showed that the diffraction peaks of the Sm2Fe17 compound shifted toward lower angle after nitrogen absorption, and the characteristic peaks of α-Fe were observed. This showed that the unit cell of Sm2Fe17 expanded, the compound was decomposed to a certain extent and the characteristic peaks of α-Fe appeared.

通过X-射线衍射、差热－热重联用仪以及磁测量等手段，研究了Sm2Fe17化合物吸氮后的相结构及居里温度的变化行为。X-射线衍射表明，吸氮后Sm2Fe17化合物的衍射峰向小角度方向偏移，并且出现了α-Fe的衍射峰，这说明吸氮后化合物的晶胞有所膨胀，并且化合物有一定的分解，产生了α-Fe。

X-ray diffraction, reflection high energy electron diffraction and Phi scan of grazing incidence X-ray diffraction with synchrotron radiation were employed to investigate the structure properties of ZnO thin film.

利用X射线衍射，反射式高能电子衍射和同步辐射掠入射X射线衍射φ扫描等实验技术研究了ZnO薄膜的结构。

In addition, molecular orientation behaviors induced by shearing, electric field and magnetic field were investigated. The space group of the monomers A3EO7 and A9EO7 were determined as P2〓2〓2 and P112/m by means of electron diffraction and X-ray diffraction. Liquid crystalline properties of the monomer and the polymer were studied using DSC, variable X-ray diffraction, TEM and polarized optical microscope. Both monomers exhibit monotropic liquid crystalline behavior, and they also give a metastable phase on the cooling process. The polymer PA9EO7 shows enantiotropic liquid crystalline properties. Thus the rigid polymer backbone is not a fatal defect that completely distorts the packing arrangement of the mesogenic moiety in the side chain liquid crystalline polyacetylene.

结合电子衍射倾转方法和粉末X射线衍射技术，确定了两个液晶小分子A3EO7和A9EO7的晶胞参数和空间群，采用Cerius〓模拟软件，运用分子模拟的方法给出了小分子在晶胞中的排列方式；利用DSC、变温X射线衍射技术和透射电子显微镜研究了小分子和聚合物的液晶态，单体A3EO7和A9EO7表现出单向液晶性质，并且在降温过程中都表现出一个亚稳液晶相或亚稳结晶相，聚合物PA9EO7具有双向液晶性；采用偏光显微镜和X射线平板照相技术，研究了剪切和电场对聚合物分子取向的影响，在不同的液晶态，剪切作用对聚合物PA9EO7具有不同的诱导取向结果，直流电场可以诱导聚合物联苯液晶基元沿施加电场方向取向。

X-ray radiography, X-ray radioscopy and X-ray computed tomography were performed to the C preforms and C/SiC composites made by chemical vapor infiltration method. Elementary research of the simulation of X-ray nondestructive testing of C preforms and C/SiC composites was conducted. The main contents and conclusions are summarized as follows:(1) The equivalent absorption coefficients of graphite and SiC to Al (KAl/sic, KAI/C) were measured. It was found that in 35-45KV, KAl/sic=1.1~1.2 and KAl/c=0.08~0.12. That means X-ray radiography was much less sensitive to fiber defects than to SiC matrix. It was suggested that Al Image Quality Indicator would be used to evaluate the quality of X-ray radiographs of C/SiC.

本文选择X射线照相、X射线实时成像和X射线CT等三种方法对C纤维预制体及C／SiC复合材料进行了检测和研究，并对C／SiC复合材料X射线检测的计算机模拟做了初步的探索，主要研究内容和结果如下：(1)测定了C和SiC的X射线照相等效系数，在35～45KV的条件下，Al对SiC的等效系数K_为1.1～1.2，Al对C的等效系数K_为0.08～0.12，所以X照相射线检测C／SiC对C纤维缺陷不敏感，而对SiC基体缺陷敏感。

X-ray ,which is excited from the X ray tube, has one wavelength scope, that is energy scope. According to the elements to be analyzed, X ray is choused by filter, and reach the sample. Atoms in the sample will absorb the X ray energy and the decay to emit the special x ray. The X ray will be collected by the collimator into the detector active area, and transferred into electron signal, the signal also will be processed in to energy spectrum and related concentration data by pulse processor with software.

从X光管通过激发Excitation发射出来一定波长范围也就是说一定能量范围的X射线，结合所需要分析的目标元素，使用滤光轮选择对应的能量范围的X射线，照射到样品上，样品中含有的元素原子电子受到激发会发射出其特征的X射线，同样通过Collimator准直器收集一定孔径的X射线进入到检测器Detector，检测器将感应到的X射线转换为电信号，电信号经过脉冲处理器Pulse Processor结合软件进一步将电信号转换成为能谱图以及相关浓度信息。

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。