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本文介绍日本理学公司生产D/MAX-RB X射线衍射仪维修一例。通过逐步分析检查,排除该仪器加高压不动作的故障,并介绍了有关电路故障的分析及排除方法。 相似文献
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为了正确表征X射线光源参数,本文利用单次全反射椭球单玻璃管X射线聚焦镜,设计了一种测量X射线光源焦斑尺寸和焦深的方法。该方法利用椭球单玻璃管X射线聚焦镜具有单次全反射成像能力的特点,对多个已知焦斑尺寸的多毛细管X光透镜模拟光源的焦斑成像尺寸和椭球聚焦镜的面形误差进行表征,从而确定光源焦斑尺寸和经过椭球聚焦镜后的焦斑成像尺寸以及椭球聚焦镜的面型误差之间的通用数学关系。然后,通过分析待测光源焦斑经过椭球聚焦镜所成像的尺寸来得到被测量光源的焦斑尺寸。利用该法也同样可以得到光源焦深的大小。为了验证设计方法的可行性,测量了实验室微焦斑X射线光源的焦斑和焦深参数。测试显示:对于焦斑直径约为50μm、焦深约为20mm的光源,文中方法得到的算术平均值标准偏差分别为1.5μm和0.7mm。结果表明:本文设计的光源参数表征方法可以实现对微焦斑源焦斑尺寸和焦深的同时测量,在X射线源的研制和应用领域具有潜在应用。 相似文献
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对国产X射线粉末衍射仪的现状进行了评述。近年国产粉末衍射仪较之以前已有很大的进步。虽与进口仪器仍有差距,但国产仪器已可满足粉末结构分析和物相分析的基本需要。现在无论应用国产衍射仪还是进口知名衍射仪,在相近的实验条件下,得到的X射线粉末衍射图数据的质量是同一水平的。 相似文献
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本文介绍的X射线衍射仪微机数据处理系统,用先进的微机技术对我国早年进口的日本理学3015X射线衍射仪进行改造。在仪器原有的测量控制下,通过简单的接口,将衍射仪及附机X荧光分析仪的测量数据准确地采集到微型计算机中,由微机来完成X衍射及X荧光分析中的各种繁琐而又重复的数据处理任务,将仪器的分析性能提高到一个新的水平。本文着重介绍微机与3015X衍射仪的硬件联接和测量数据的采集。 相似文献
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用离心自蔓延高温合成法制备氧化铝陶瓷复合钢管。用 X射线衍射仪测定了陶瓷层的相成分 ,研究了添加剂 Si O2 对陶瓷复合钢管孔隙度及力学性能的影响。 相似文献
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现有变电站运行状态GIS检测工作,难以确保所有高压输电站都能实现每年一次的检修工作,因此研究了X射线无损探伤技术,并将其应用在变电站运行状态GIS检测中。预先设计了X射线防护装置,屏蔽高压电磁脉冲对X射线机的干扰;在此基础上,构建X射线相机模型,并选择合适的管电压、管电流,明确工件对比度和成像板灵敏度;通过几何变换、灰度变换、图像平滑和阈值分割手段,处理GIS检测图像,实现检测变电站运行状态。实验测试结果可知,当施加电压超过150kV时,无防护装置的X射线机被高压脉冲干扰,无法显示检测结果;而有防护装置的测试组中,当施加电压超过330kV时,X射线机依旧可以显示GIS检测结果。可见此次应用的X射线无损探伤技术,在防护装置的辅助下,可以更好地实现变电站运行状态检测。 相似文献
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Quality of low and medium energy X-ray beam at the National Institute for Standards (NIS) of Egypt is studied in details in accordance with the recommendations of the Bureau International des Poids et Measures (BIPM) consultative committee for ionizing radiation (CCRI). The Half Value Layer (HVL) at each applied voltage is precisely determined. The setting up for the X-ray tube according to the TRS No. 469 of IAEA is performed. The effective energy of X-ray is determined using Hyper Pure Germanium Detector (HPGD) connected to photon energy spectrometer. The X-ray air Kerma is measured using NIS secondary standard dosimetry system, which is traceable to the SI units through BIPM. A proposed method for non-invasive tube voltage determination by HPGD is performed. Consequently, all X-ray beam quality parameters are extracted and found to be complying with CCRI recommended values for NIS X-ray tube. 相似文献
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P. A. Rodnyi A. N. Mishin S. B. Mikhrin A. V. Rozhkov 《Instruments and Experimental Techniques》2000,43(5):698-700
A small-sized source of short X-ray pulses is described, whose basic components are a three-electrode X-ray tube operating
at 30 kV and 0.5 A and a fast GaAs modulator connected coaxially to the tube grid. The limiting operating parameters of the
source are a subnanosecond pulse duration and a pulse repetition rate as high as 100 kHz. 相似文献
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The design of the first domestic microfocus X-ray tube with massive target and electrostatic 200-kV electron-beam focusing is presented. A monoblock X-ray device based on this tube and intended for projection radiography is described. The main characteristics of the X-ray unit, including its fluoroscopic parameters, are estimated. 相似文献
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S. Pandia Rajan S. Senthil Kumaran L. A. Kumaraswamidhas S. Muthukumaran 《Journal of Mechanical Science and Technology》2016,30(1):337-344
Friction welding of tube to tube plate using an external tool (FWTPET) is a relatively newer solid state welding process used for joining tube to tube plate of either similar or dissimilar materials with enhanced mechanical and metallurgical properties. In the present study, FWTPET has been used to weld SA 213 (Grade T12) tube with SA 387 (Grade 22) tube plate. The welded samples are found to have satisfactory joint strength and the Energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) study showed that inter metallic compound is absent in the weld zone. The different weld joints have been identified and the phase composition is found using EDX and XRD. Microstructures have been analyzed using optical and Scanning electron microscopy (SEM). The mechanical properties such as hardness, compressive shear strength and peel test for different weld conditions are studied and the hardness survey revealed that there is increase in hardness at the weld interface due to grain refinement. The corrosion behavior for different weld conditions have been analyzed and the weld zone is found to have better corrosion resistance due to the influence of the grain refinement after FWTPET welding process. Hence, the present investigation is carried out to study the behavior of friction welded dissimilar joints of SA 213 tube and SA 387 tube plate joints and the results are presented. The present study confirms that a high quality tube to tube plate joint can be achieved using FWTPET process at 1120 rpm. 相似文献
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为了提高航空发动机轴承故障诊断的准确率,提出基于改进遗传算法优化(back propagation,简称BP)网络(modified genetic algorithm to optimize BP,简称MGA-BP)的故障诊断模型。针对传统遗传算法易早熟、易陷于局部最优解等缺陷,利用固定个体选择概率、引入三角函数和高斯变异操作对遗传算法进行改进,并用改进遗传算法优化BP网络的权值和阈值。利用优化的BP网络对滚动轴承正常、内圈故障、外圈故障和钢球故障4种工况进行诊断,并考虑到网络输出模式、诊断样本比例等对诊断精度的影响。为了验证MGA-BP在轴承故障诊断中的有效性,将其他改进遗传算法优化BP网络作为对比算法。分析表明:MGA-BP能够较好地适应网络不同的输出模式、不同的样本比例,其抗噪能力、诊断准确率、误差收敛速度和误差收敛值均优于文中其他对比算法。 相似文献