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定向X射线探伤仪辐射角及中心偏移检测方法研究
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作者 周迎春 杨学泉 《中国测试技术》 2008年第5期98-102,共5页
辐射角及中心偏移,是定向X射线探伤仪的重要技术指标。应用现行的X射线探伤仪计量检定规程和相关行业标准中的检测方法,检测成本高,仪器设备昂贵。为研究一种简单易行、准确可靠的检测方法,提出了针像拍片成像法,通过借助一套简单辅助器... 辐射角及中心偏移,是定向X射线探伤仪的重要技术指标。应用现行的X射线探伤仪计量检定规程和相关行业标准中的检测方法,检测成本高,仪器设备昂贵。为研究一种简单易行、准确可靠的检测方法,提出了针像拍片成像法,通过借助一套简单辅助器具,不但可检测辐射角及中心偏移,而且定位准确。实验结果表明,该方法简便,解决了射线窗口中心定位问题,提高了检测准确度,其准确度可与准确定位时剂量扫描法相媲美,并可解决剂量扫描法不适用的情况,完全满足实际检测要求。 展开更多
关键词 定向X射线探伤仪 辐射角 中心偏移 针像拍片法
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Effect of Copper Content on the Direct Process of Organosilane Synthesis from Silicon and Methyl Chloride 被引量:4
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作者 罗务习 张国良 +1 位作者 王光润 王金福 《Tsinghua Science and Technology》 SCIE EI CAS 2006年第2期252-258,共7页
The effect of copper concentration on the performance of the catalytic reaction between silicon and methyl chloride was investigated using online gas chromatogram. The catalyst concentration greatly influences various... The effect of copper concentration on the performance of the catalytic reaction between silicon and methyl chloride was investigated using online gas chromatogram. The catalyst concentration greatly influences various aspects of the direct organosilane synthesis process, including the reaction rate, the selec- tivity, and the silicon conversion. The reaction activity and the silicon conversion increase as the catalyst concentration increases. However, the reaction selectivity decreases for the catalyst concentrations more .than 9 wt.%. The cross-sections of deactivated contact mass particles were observed by optical microscopy and analyzed by scanning electron microscope combined with energy dispersive X-ray detector (SEM-EDX) The observations showed that a textured substance formed on the original flat surface of the silicon particles after deactivation with copper only in a shallow surface layer of the contact mass. This indicates that the copper diffusion is the rate limiting step which causes the reaction deactivation. 展开更多
关键词 direct process copper concentration reaction activity reaction selectivity silicon conversion online gas chromatogram (GC) scanning electron microscope combined with energy disper-sive x-ray detector (SEM-EDX)
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