共查询到19条相似文献,搜索用时 109 毫秒
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目的研究飞机外场条件下适用的腐蚀损伤检测方法。方法针对某型飞机铝合金和结构钢的腐蚀损伤特点,采用X射线CR(计算机放射成像系统,Computed Radiography,简称CR)、X射线DR(Digital Radiography,简称DR)、红外热波检测等无损检测方法对铝合金和结构钢的典型腐蚀损伤件进行检测,优选及并验证适合用于飞机腐蚀损伤的外场检测方法。结果 X射线CR检测方法可检测铝合金和结构钢单层隐蔽腐蚀损伤和多层隐蔽裂纹,X射线DR检测方法可检测铝合金和结构钢单层/多层隐蔽腐蚀损伤/裂纹,红外热波检测方法只可检测铝合金和结构钢单层隐蔽腐蚀损伤。结论相较于X射线CR和红外热波检测方法,X射线DR成像检测方法能够更可靠、便捷地检测铝合金和结构钢单层/多层结构隐蔽腐蚀/裂纹损伤,更适于飞机结构腐蚀损伤的外场检测。 相似文献
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张济宇 《石油化工环境保护》2002,(1)
为了掌握柴油机排气中微粒 ( DEP)和轮胎磨损粉尘微粒等大气环境中微粒的准确特性 ,碳等轻元素组成情报就是一个重要的因素。虽以前用散能 X射线光谱仪 ( EDS)检测原子序数 1 0以下的轻元素困难 ,但近年来开发了聚丙烯超薄膜检测孔的散能 X射线光谱仪 ( EDS)析测器 ,就可以测定这些轻元素特性 X射线。如使用备有电子探针 X射线显微分析 ( EPMA)装置新的散能 X射线显微分析 ( EDS)和新开发的试样前处理法及试样捕集法 ,就能实现掌握柴油机排气中微粒 ( DEP)和轮胎磨损粉尘微粒等的准确的特性。另外 ,根据扫描电子显微镜( SEM)观测… 相似文献
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本文概略地述评了X射线衍射方法在地学方面的应用现状:单晶结构分析和结构矿物学及其发展;X射线粉末法,特别是晶胞参数测定方法在造岩矿物研究中的应用;用单晶X射线照相研究造岩矿物调制结构;X射线粉末法在粘土矿物学及煤岩学上的应用,等等。 同时,还介绍了笔者在用X射线粉末法及单晶分析研究造岩矿物方面的主要成果。 相似文献
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<正> 四、质子激发X射线发射光谱(PIXE) 和重离子散射谱分析质子激发X射线发射光谱(Proton InducedX-Ray Emissian,简称PIXE)分析是60年代末发展起来的一种新的微量分析技术,其发展是与粒子加速器技术愈来愈广泛的应用分不开的。与基于光电效应的X射线荧光法不同,这属于带电粒子激发的X射线发射,与电子激发X射线的过程类似。带电粒子激发X射线的截面随粒子能量的升高和被激发原子序数的降低而增大,而且呈单调连续变化。这与光电效应的过程恰恰相反。首先,光电效应的截面随光子能量呈 相似文献
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《Atmospheric Environment. Part A. General Topics》1993,27(15):2441-2444
Speciation results from earlier methods of quantitative analysis of TSP, dichotomous, and PM10 filters for compounds by XRD were often marginal to unacceptable because of very light loadings and the interfering effects of substrate fibres in cases of ultrasonic extraction and concentration. A method for analysis of very lightly loaded PM10 filters has been developed, using ultrasonic particle stripping, X-ray transmission of unloaded blank filters, substrate diffraction X-ray analysis, and mass absorption balance, along with the usual X-ray diffraction scanning. Analysis of a set of filters having less than 105 μg m cm−2 sample load is used to illustrate the improved procedure. 相似文献
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为了获取尽可能完整的样品信息,直接利用采集的大气PM10原样进行非晶质X射线衍射(XRD)的定量分析.按照实际PM10的构成用玻璃纤维滤膜采集人为模拟大气结晶颗粒物样品,结合实验拟合得到的滤膜衍射图,推导出根据空白滤膜衍射强度计算不同样品载量时滤膜的衍射强度公式,从而消除了滤膜的基底效应的影响,并计算出实际大气样品中非晶质的衍射强度.采用无定形碳模拟大气中的非晶质,通过测定纯碳的衍射强度,得到纯碳比空白玻璃纤维滤膜的参比强度K为0.59,类比绝热法求出非晶质的质量百分比.应用该方法对北京市2010年冬季采集到的一组大气可吸入颗粒物样品进行了原样XRD分析,得出其非晶质含量分别为10.44%、13.83%、15.12%、15.88%和11.96%. 相似文献
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《Atmospheric Environment. Part B. Urban Atmosphere》1992,26(2):159-163
The deterioration of sandstone, marble and granite has been studied under ambient atmospheric conditions. Specially constructed sampling devices, called “micro catchment units”, were installed to sample the run-off water, i.e. the rain water that flows over the stones. Several analysis techniques were invoked for the analysis of the bulk run-off water, as well as electron probe X-ray microanalysis for individual particles in the run-off. An overview of the work is given and preliminary results are discussed. 相似文献
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X射线荧光光谱分析法在土壤样品多元素分析中的应用 总被引:3,自引:0,他引:3
用Epsilon5偏振能量色散X射线荧光光谱仪测定土壤样品中27种元素。方法的准确度用GBW07323和GSS-32标准样品验证,结果均在标准值范围内。方法的精密度用GBW07401标准样品检验,除Ni、Mo、Se和Pr四种元素的RSD〉10%外,其余被测元素的RSD均〈6.3%。实验表明用X射线荧光光谱分析法测定土壤样品中多种元素,具有方法简便、灵敏、准确,检出限低等特点。 相似文献
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Microwave absorbing material plays a great role in electromagnetic pollution controlling, electromagnetic interference shielding and stealth technology, etc. The core-nanoshell composite materials doped with La were prepared by a solid-state reaction method, which is applied to the electromagnetic wave absorption. The core is magnetic fly-ash hollow cenosphere, and the shell is the nanosized ferrite doped with La. The thermal decomposition process of the sample was investigated by thermogravimetry and differential thermal analysis. The morphology and components of the composite materials were investigated by the X-ray diffraction analysis, the microstructure was observed by scanning electron microscope and transmission electron microscope. The results of vibrating sample magnetometer analysis indicated that the exchange-coupling interaction happens between ferrite of magnetic fly-ash hollow cenosphere and nanosized ferrite coating, which caused outstanding magnetic properties. The microwave absorbing property of the sample was measured by reflectivity far field radar cross section of radar microwave absorbing material with vector network analyzer. The results indicated that the exchange-coupling interaction enhanced magnetic loss of composite materials. Therefore, in the frequency of 5 GHz, the reflection coefficient can achieve ?24 dB. It is better than single material and is consistent with requirements of the microwave absorbing material at the low-frequency absorption. 相似文献
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Microwave absorbing material plays a great role in electromagnetic pollution controlling, electromagnetic interference shielding and stealth technology, etc. The core-nanoshell composite materials doped with La were prepared by a solid-state reaction method, which is applied to the electromagnetic wave absorption. The core is magnetic fly-ash hollow cenosphere, and the shell is the nanosized ferrite doped with La. The thermal decomposition process of the sample was investigated by thermogravimetry and differential thermal analysis. The morphology and components of the composite materials were investigated by the X-ray diffraction analysis, the microstructure was observed by scanning electron microscope and transmission electron microscope. The results of vibrating sample magnetometer analysis indicated that the exchange-coupling interaction happens between ferrite of magnetic fly-ash hollow cenosphere and nanosized ferrite coating, which caused outstanding magnetic properties. The microwave absorbing property of the sample was measured by reflectivity far field radar cross section of radar microwave absorbing material with vector network analyzer. The results indicated that the exchange-coupling interaction enhanced magnetic loss of composite materials. Therefore, in the frequency of 5 GHz, the reflection coefficient can achieve -24 dB. It is better than single material and is consistent with requirements of the microwave absorbing material at the low-frequency absorption. 相似文献
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The selective introduction of compressive residual stresses is gaining increasing importance as design tool in today's manufacturing process chains. Manufacturing processes such as shot peening or hydraulic autofrettage are used to improve the surface integrity, and hence the fatigue life of the components. However, measuring the corresponding residual stress depth profiles is a challenging task as the results will always include the manufacturing and preparation history of the components. In this paper, results of residual stress measurements with X-ray diffraction and optical hole-drilling after autofrettage and sample preparation are presented and compared to a finite element analysis for two representative geometries. The presented approach can be used to predict the influence of the mandatory sample preparation procedure. As a consequence, the effectiveness of the manufacturing process to improve the surface integrity can be predicted more precisely and wrong interpretations of the measured residual stress depth profiles can be avoided. 相似文献