首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
报道了以铑(Ⅲ)催化溴酸钾氧化二溴硝基偶氮氯膦的褪色反应,建立了一种在水相中直接测定微量铑的催化光度分析法.铑含量在0.0~12.0μg·L-1范围内符合比耳定律.用于铂铑催化剂中铑的测定,结果满意.  相似文献   

2.
以铑(Ⅲ)催化溴酸钾氧化二溴邻硝基偶氮胂的褪色反应,建立了一种在水相中直接测定微量铑的催化光度分析法.铑含量在0.0-20.0μg.L-1范围内符合比耳定律.用于铂-铑催化剂中铑的测定,结果令人满意.  相似文献   

3.
报道了以铑(Ⅲ)催化溴酸钾氧化二溴羧基偶氮肿的褪色反应,建立了一种在水相中直接测定微量铑的催化光度分析法.铑含量在0.0~10.0μg·L-1范围内符合比耳定律.用于铂-铑催化剂中铑的测定,结果满意.  相似文献   

4.
在H2SO4介质中钌对高碘酸钾氧化二溴硝基偶氮氯膦的褪色反应有明显的催化作用.本文研究了该褪色反应的最佳条件及用于痕量钌的测定方法.其检出限为0.02μg*10mL-1,钌含量在0.02~0.25μg*10mL-1范围内线性关系良好.该方法已成功用于贵金属精矿和钌合成样中钌含量的测定.  相似文献   

5.
二溴硝基偶氮氯膦用于微量铂系元素测定的应用研究   总被引:1,自引:0,他引:1  
作为不对称变色酸双偶氮试剂的二溴硝基偶氮氯膦与金属钯可发生显色反应,而与同属铂系元素的其他五种金属的显色反应并不明显;可是在高碘酸钾、溴酸钾等氧化剂的存在下,它们却能使二溴硝基偶氮氯膦发生催化褪色反应.从而建立了用直接光度法测定钯和用催化光度法测定钌、铑、锇、铱、铂的微量分析新方法.本文考察了该系列水相中直接测定铂系元素反应的最佳条件,并提出了贵金属样品中微量铂系元素的测定方法.  相似文献   

6.
污水中微量铬的测定   总被引:1,自引:0,他引:1  
研究了用二溴硝基偶氮氯膦分光光度法测定污水中微量铬的新方法。实验表明,pH值在2.7~3.8时,铬(Ⅲ)与二溴硝基偶氮氯膦生成1:2的配合物,其最大吸收波长为624nm,表观摩尔吸光系数=ε1.1×104L.m o-l 1.Cm-1,铬(Ⅲ)在0~20μg/25m l范围内符合比尔定律,该方法简单快速、准确,用于污水中铬的测定,结果满意。  相似文献   

7.
在酸性介质中,痕量Rh(Ⅲ)的存在对KBrO3 氧化二溴对甲偶氮羧的褪色反应有明显的催化作用.据此褪色反应建立了测定痕量铑的动力学催化光度分析方法.铑检出限为 0.001μg·mL-1,在 0.002~0.050μg·mL-1范围内符合比耳定律.反应在水相中进行,重现性好,用于铂 铑催化剂中铑的测定,结果满意.  相似文献   

8.
不对称变色酸双偶氮试剂是分光光度法测定稀土元素的灵敏显色剂,三氯偶氮氯膦[2-(4-氯-2-膦酸基苯偶氮)-7-(2,4,6-三氯苯基偶氮)-1,8-二羟基-3,6-二磺酸萘]应用于催化光度法测定微量钌、铑已有报道,但用于铂的测定未见报道.  相似文献   

9.
报道了以铂(Ⅳ)催化溴酸钾氧化二溴羧基偶氮胂的褪色反应,建立了一种在水相中直接测定微量铂的催化光度分析法.铂含量在1.0~25.0 μg·L-1范围内符合比耳定律.检出限量为1.0μg·L-1.用于铂-铑催化剂和铂-钯精矿中铂的测定,结果满意.  相似文献   

10.
在钯(Ⅱ)与对乙酰基偶氮氯膦络合物的溶液中加入吐温-80,可形成稳定的三元显色体系.其灵敏度显著提高,表观摩尔吸光系数ε650=8.0×104L·mol-1·cm-1,钯含量在0.1~1.0μg·mL-1范围内符合比耳定律.同时,方法的选择性亦有所改善,可在水相中直接测定微量钯,在钯催化剂及二次阳极泥微量钯的测定中,获得满意结果.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

13.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

14.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

15.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

16.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

17.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

18.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号