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1.
在H2SO4介质中,微量铂(Ⅳ)、铑(Ⅲ)的存在对溴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.该文研究了二溴硝基偶氮氯膦催化动力学光度法测定微量铂、铑的最佳条件及测定方法.铂、铑的检出限分别为0.005μg.mL-1和0.002μg.mL-1,其含量在0.005~0.050μg.mL-1范围内线性关系良好.铂-铑催化剂中铂、铑含量可同时测定.  相似文献   

2.
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   

3.
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   

4.
本文详细报导了以间溴苯胺为原料合成偶氮溴膦Ⅲ的路线和操作方法,并用 HMO 法计算了偶氮溴膦Ⅲ分子的电子光谱,依据自编的 OSHMO 程序在 IMS-8000微电脑系统上的计算结果绘制出了它的分子图。凭借π分子轨道能级能量差及选定的β参数数值,推算出电子光谱的吸收峰波长位置。本文还报导了该试剂与铀(Ⅵ)、钍和稀土的显色反应情况:在酸性介质中试剂与铀(Ⅵ)形成绿色络合物,其最大吸收峰在 672nm,摩尔吸光系数为9.4×10~4,灵敏度比偶氮氯膦Ⅲ(ε为7.6×10~4)和偶氮硝膦Ⅲ(ε为9.2×10~4)更高。  相似文献   

5.
本文详细报导了以间溴苯胺为原料合成偶氮溴膦Ⅲ的路线和操作方法,并用 HMO 法计算丁偶氮溴膦Ⅲ分子的电子光谱,依据自编的 OSHMO 程序在 IMS-8000微电脑系统上的计算结果绘制出了它的分子图。凭借π分子轨道能级能量差及选定的β参数数值,推算出电子光谱的吸收峰波长位置。本文还报导了该试剂与铀(Ⅵ)、钍和稀土的显色反应情况:在酸性介质中试剂与铀(Ⅵ)形成绿色络合物,其最大吸收峰在672nm,摩尔吸光系数为9.4×10~4,灵敏度比偶氮氯膦Ⅲ(ε为7.6×10~4)和偶氮硝膦Ⅲ(ε为9.2 x 10~4)更高。  相似文献   

6.
间硝基偶氮氯膦是一种不对称变色酸双偶氮氯膦酸型显色剂,其化学名称为2-(4一氯-2磷酸基偶氮)-7-(3-硝基苯偶氮)-1,8二羟基-3,6萘二磺酸(英文缩写为CPAmN),其结构式为 CPAmN是深红色晶体,易溶于水,在酸性溶液中呈红色,与稀土离子形成蓝或绿色络合物。在试剂过量时,铈(Ⅲ)与CPAmN形成1:3的络合物。用草酸为掩蔽剂和CPAmN为显色剂,可掩蔽钇组稀土而测定铈组稀土元素。本文试验了测试条件,进一步应用于测定铝合金中微量铈组稀土元素,国内外未见报道。在实验条件下,测定铈(Ⅲ)和镧(Ⅲ)的摩尔吸光系数依次为7.6×10~4、7.8×10~4升·摩尔~(-1)·厘米~(-1)。桑德尔灵敏度依次为0.00184微克铈(Ⅲ)·厘米~(-2)、0.00178微克镧(Ⅲ)·厘米~(-2)。比尔定律的范围依次为0~12微克铈(Ⅲ)、0~10微克镧(Ⅲ)/25毫升。五倍钇存在时无干扰。依10次平行测定,计算得变异系数分别为铈0.68%、镧0.87%。铈的回收率为95~105%。用本法测定铝合金中含0.02%以上的微量铈组稀土元素,可获得满意结果。  相似文献   

7.
钯(Ⅱ) -二溴硝基偶氮氯膦在硫酸介质中加热时可形成蓝色络合物.本文研究了络合物形成的最佳条件及用于微量钯的测定方法.摩尔吸光系数ε592=1.6×104 L· mol-1·cm-1; 钯含量在0.10~1.0mg·L-1范围内符合比耳定律.该方法已成功用于废钯催化剂回收液中钯含量的测定.  相似文献   

8.
偶氮氯膦-mA褪色光度法测定稀土中的铈含量   总被引:2,自引:0,他引:2       下载免费PDF全文
陶慧林 《广西科学》2006,13(1):40-42
用偶氮氯膦-mA褪色光度法测定稀土中微量铈的含量,研究铈(Ⅳ)氧化偶氮氯膦-mA(CPA-mA)的褪色反应条件。结果表明,体系最大吸收波长在545nm处;在H2SO4介质中,铈(Ⅳ)量在0~3.2m g/L范围与偶氮氯膦-mA的褪色程度呈良好的线形关系,表观摩尔系数为5ε45=1.30×104L.m o-l 1.cm-1,相关系数γ=0.9989。本方法应用于稀土氧化物中铈的测定,结果与原值相符,6次测定的RSD小于4.3%,平均加标回收率为97%~104%。  相似文献   

9.
本文提出了稀土—间硝基偶氮氯膦,稀土-间硝基偶氮氯膦-二苯胍的两个极谱络合吸附波体系,并用库仑分析,对照实验和循环伏安等方法研究了间硝基偶氮氯膦的电化学行为,解释了单扫极谱上各个波峰的电极过程。稀土与间硝基偶氮氯膦的络合部位在分子的氯膦一侧。络合物中氯膦一侧偶氮基酶还原形成了络合吸附峰。  相似文献   

10.
木文研究了新稀土显色剂二溴一氯-偶氮氯膦(DBC-CPA)与稀土元素的显色反应.该试剂在HCl—NaAc 介质中能与稀土形成稳定的兰紫色6∶1络合物,平均摩尔吸光系数ε为1.04×10~5l·mol~(-1)·cm~(-1),并采用EDTA 掩蔽大量铁,导数光谱法消除Ca 的干扰,测定了矿石中的稀土总量.  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.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
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   

16.
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   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

19.
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   

20.
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   

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