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1.
本文研究了邻菲罗啉氮氧化物-铜(Ⅱ)-过氧化氢化学发光体系的最佳反应条件,拟定了新的化学发光测定痕量铜的方法。本方法检出限为7.9×10 ̄(-9)mol/L,线性响应的浓度范围为1.6×10 ̄(-8)~1.6×10 ̄(-6)mol/L。考察了共存离子的干扰情况,用于铜精矿、茶叶及发样中铜的测定获得满意结果。本文还探讨了该体系化学发光的可能机理。  相似文献   

2.
研究发现镝与邻氟苯甲酸(o-FBA)有较强的荧光反应,并观察到镧存在下的共发光现象.研究了该反应的荧光特点和影响因素,确定了反应和测定的最佳条件.镧的加入使原有的镝—邻氟苯甲酸—乙二胺体系的荧光强度增大了85倍.在最佳条件下,浓度在5.0×10-6~5.0×10-5mol·L-1范围内与荧光强度成线性关系,检测限为1.0×10-6mol·L-1.采用多点增量标准加入法测定了合成稀土样品中镝的含量.  相似文献   

3.
大孔树脂固定化葡萄糖异构酶及其动力学研究   总被引:3,自引:0,他引:3  
研究了用大孔径聚丙烯腈树脂固定化葡萄糖异构酶的方法及固定化酶的性质.固定化酶活力达到4.6296×10-6mol·g-1·s-1左右.同时研究了固定化酶的反应动力学,测得其米氏常数Km=6.00mol·L-1,最大反应速度Vmax=1.40×10-5mol·g-1·s-1.  相似文献   

4.
间接邻菲罗啉光度法测定氨基甲酸酯农药   总被引:4,自引:0,他引:4  
N-氨基甲酸酯农药经二次水解可产生经胺,利用径胺的还原性可将Fe3+定量还原为Fe2+。后者与邻菲罗啉生成桔红色络合物,λmax=508nm,可用于试样的分光光度法测定,其线性范围在4.2x10-6~2.1x10-5mol/L。  相似文献   

5.
本文用8-羟基喹啉修饰的铅笔芯电极研究了铜的阶梯阳极溶出伏安特性,并将此法用于人发中微量铜的测定。实验指出,在此修饰电极上,铜的阶梯溶出峰有两个,1#峰电位在-0.03V,2#峰电位在0.27V处。同样的试液和条件下,1#峰总比2#峰的峰电流大。实验研究了测定铜的最佳条件,并测得铜的浓度在4.0×10-8~1.6×10-6mol·L-1范围内,1#峰的峰高与浓度呈良好的线性关系,最低检测限为2×10-8mol·L-1。2#峰高与铜的浓度在6.0×10-8~1.6×10-6mol·L-1范围内也有较好的线性关系,也可用于测定铜。本文还分析了铜在修饰电极上的反应机理  相似文献   

6.
邻菲罗啉化学修饰碳糊电极三元络合物体系测定痕量钴   总被引:3,自引:0,他引:3  
制备了邻菲罗啉化学修饰碳糊电极,在含噻吩甲酰三氟丙酮的HAc-NaAc体系中,Co(Ⅱ)离子经化学富集在电极一须上形成三元络合物,采用2.5次微分伏安法测定痕量Co(Ⅱ)离子,Co(Ⅱ)浓度在8.0×10^-9~7.0×10^-7mol.L^-1范围内与阳极溶出峰峰高成良好的线性关系,检出限达1.2×10^-9mol.L^-1电极用于水样中钴的测定,结果令人满意。  相似文献   

7.
拟定了测定痕量钼的新催化光度法,方法基于盐酸联氨还原苯胺蓝钼(Ⅵ)的催化效应。研究了溶液pH值、试剂浓度和干扰离子对反应速率的影响,讨论了催化反应的机理。在不同温度条件下,测定钼的线性范围是0.1~1.5mg·L-1,检出限是1.2×10-2mg·L-1相对标准偏差是2.4%,催化反应的表现活化能是44.7kJ·mol-1.方法用于测定豆样品中痕量钼。  相似文献   

8.
四氢呋喃与六氢苯酐共聚的研究   总被引:1,自引:1,他引:0  
研究了四氢呋喃(THF)与六氢苯酐(HHPA)共聚合的动力学行为,并测定了6℃和18℃条件下THF的表观聚合速度常数分别是1.5×10-2L/(mol·s)和2.05×10-2L/(mol·s);HHPA的表观聚合速度常数分别是1.38×10-3L/(mol·s)和1.62×10-3L/(mol·s).  相似文献   

9.
本文研究结果表明,水溶性大分子化合物阿拉伯胶和非离子表面活性剂TritonX-100共同存在下,锑碘配阴离子和罗丹明B的显色反应具有很高的灵敏度。缔合物的最大吸收在5g0nm,摩尔吸光系数ε=6.1×10 ̄5L·mol-1·cm-1。用巯基棉富集锑,分离干扰离子。本法可应用于有色金属中痕量锑的测定。  相似文献   

10.
本文用荧光光度法对酸性介质中甲氧氯普胺和十二烷基硫酸钠形成的胶束配合物的性能进行了系统研究。利用胶束的增敏增稳作用,提出了测定甲氧氯普胺的荧光光度新方法。本法线性范围宽,为1.3×10-8~8.0×10-6mol·L-1,灵敏度高,检出限为1.2×10-8mol·L-1。应用本法于样品中甲氧氯普胺的测定,平均回收率为98.8%,结果令人满意。  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.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
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   

19.
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   

20.
<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   

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