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本文研究了550螯合树脂对铜的吸附性能,进行了分离富集条件的选择,观察了铜与钴等多种共存离子的分离效果。结果表明,550螯合树脂对铜吸附性能良好,能从大量钴中分离微克量铜。拟定了钴电解液中微量铜的测定方法。初步应用效果好。回收率为90—102%,相对标准偏差小于5%。 相似文献
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水相和有机相中钼的快速测定 总被引:1,自引:0,他引:1
国外曾有人提出在大于11.5M的磷酸介质中,用亚铁直接还原滴定水相中六价钼。方法简便,测定纯钼溶液中的钼,准确度高。但由于变价元素如铀,铬等严重干扰,限制了方法的应用。我们在观察了一些元素对亚铁还原滴定钼的影响后,选用六偏磷酸钠络合消除铀的干扰,同时,用抗坏血酸还原隐蔽Cr(Ⅵ),Ce(Ⅳ)等元素的干扰(此 相似文献
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WHISPERING-GALLERY MODE STRUCTURE IN SEMICONDUCTOR MICRODISK LASERS AND CONTROL OF THE SPONTANEOUS EMISSION FACTOR 总被引:1,自引:0,他引:1 下载免费PDF全文
The mode density and cross-sectional area of whispering-gallery modes of various possible polarizations existing in a microdisk cavity structure have been investigated and compared in some detail. Their variations with the disk thickness and radius have been calculated and the behavior of the spontaneous emission factor controlled by the microdisk structure have been shown. It is found that for a given microdisk thickness, the spontaneous emission factor increases with decreasing microdisk radius, but decreases after passing a maximum value, This non-monotonic behavior has never been noted before by others. The variation of spontaneous emission factor with respect to microdisk thickness also exhibits similar behavior. For a microdisk laser emitting at 1.5 μm wavelength, the enhanced spontaneous emiasion factor can barely exceed 0.2. A device configuration for improving the coupling between the whispering-gallery mode and the active region, and for leading the laser beam out of this high-Q microcavity is proposad, and its feasibility in realizing a thresholdless laser is discussed. 相似文献
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