排序方式: 共有44条查询结果,搜索用时 15 毫秒
1.
用偶氮胂Ⅲ作钪的比色试剂 总被引:1,自引:0,他引:1
用偶氮肿Ⅲ试剂比色测定钪,在国外资料上早有报导。国内似未见刊载。试验证明,灵敏度和选择性(尤其是选择性)皆优于常用的显色剂茜素磺酸钠以及二甲酚橙。本文拟就该试剂比色测定钪的有关问题暨钨精矿中测定钪的方法予以报导。 相似文献
2.
3.
邻硝基荧光酮-聚乙二醇辛基苯基醚分光光度法测定铜矿中微克级钼 总被引:2,自引:0,他引:2
本文研究了乳化剂OP存在时Mo(Ⅵ)与ο-NPF的显色反应。试验表明,在0.01—0.045mol/L硫酸中,络合物的最大吸收位于513nm,摩尔吸光系数为1.4×10~5,络合物组成为Mo(Ⅵ):ο-NPF:OP=1:4:3,不稳定常数K_不=1.3×10~(-6)。铜量在0—20μg范围内符合比尔定律,络合物显色后吸光度在3小时内不变。标准加料回收率为99—101%。Fe(Ⅲ)、Cu(Ⅱ)、ln(Ⅲ)、Tl(Ⅰ)、As(Ⅲ)不影响测定。本法已应用于铜矿中μg级钼的测定,结果满意。 相似文献
4.
电位滴定法同时测定水体中碘溴氯 总被引:2,自引:0,他引:2
在弱酸性介质中,以双液接(外管盛4 mol LKNO_3)甘汞电极为参比电极、P_(AB)电极为指示电极、用硝酸银连续电位滴定碘、溴、氯离子,其精密度与共存的碘、溴含量密切相关。在1mol L硝酸中滴定,不仅有较大的电位突跃,而且不同量的碘与500μg溴共存时,不影响彼此的测定硫酸钾的存在可使溴的滴定终点更趋敏锐,且dE dv峰值均提高1倍以上,峰尾的滞留现象也显著消失在1mol L硝酸—2×10~2mol L硫酸钾介质中进行测定,下列共存离子(以mg计)SO_4~(2-)(100)、Fe~(3(?))(20)、Fe~(2+)、(20)、 相似文献
5.
针对双孔复合封闭储层模型 ,研究了两种内边界条件下的变流率问题的无因次井底压力的Laplace空间解 ,在深入剖析解的结构的基础上 ,找出了它与常见的复合、双孔、均质储层井底压力之间的关系 .该研究是对试井分析理论的一种完善 ,对油藏数值模拟方法也具有指导意义 相似文献
6.
郭志英 《晋中师范高等专科学校学报》2000,17(3):71-72
知识经济时代,高等教育面临着严峻挑战,高校管理工作者只有具备乐观向上、正视挫折、开朗豁达的良好心理素质,才能创新管理工作,提高管理绩效。 相似文献
7.
Ca-based additives have been widely used as a sulfur adsorbent during coal pyrolysis and gasification. The Ca speciation and evolution during the pyrolysis of coal with Ca additives have attracted great attention. In this paper, Ca species in the coal chars prepared from the pyrolysis of Ca(OH)2 or CaCO3-added coals are studied by using Ca K-edge X-ray absorption near-edge structural spectroscopy. The results demonstrate that Ca(OH)2 , CaSO4 , CaS and CaO coexist in the Ca(OH)2-added chars, while Ca(OH)2 and CaSO4 are the main species in the Ca(OH)2-added chars. Besides, a carboxyl-bound Ca is also formed during both the pyrolysis for the Ca(OH)2-added and the CaCO3-added coals. A detailed discussion about the Ca speciation is given. 相似文献
8.
To improve the performance of Beamline 3W1B at the Beijing Synchrotron Radiation Facility for the soft X-ray magnetic linear dichroism research at transition metals L2, 3 edges, a new monochromator was designed and built to replace the original one. After the assemblage, alignment and adjustment of the monochromator system, the first commissioning results were obtained. The photon energy range is from 50 to 1000 eV with spectral resolutions of 1600 at 250 eV and 1000 at 870 eV. The photon flux is of the order of 108-109 photons/s/200 mA/0.1%BW. In the electron's orbital plane the linear polarization degree of the light is higher than 99% at 704 eV. The beamline has satisfied the basic experimental requirements. 相似文献
9.
10.