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1.
水中氟的快速测定   总被引:4,自引:0,他引:4       下载免费PDF全文
研究了在氟离子作用下能使其变色的显色体系,经试验选择了一种显色体系配以酸度调节剂、掩蔽剂、表面活性剂等,以层析纸为载体制成氟试纸,并对试纸的性能进行了试验,确定其使用方法和储存条件,实际水样用试纸法和国标法比较,测定结果基本符合,误差在半定量分析允许范围内。  相似文献   

2.
从pH试纸的制作中得到启发。通过对显色剂、氧化剂、缓蚀剂、缓冲体系的分别选择确定一种简便易行,效果良好的显色体系的组成成分。利用显色剂与不同浓度铁离子溶液进行显色反应制得标准色阶。将显色体系溶液喷涂到钢铁基材表面进行显色反应,对照标准色阶对钢铁锈蚀程度定量分析。  相似文献   

3.
从pH试纸的制作中得到启发。通过对显色剂、氧化剂、缓蚀剂、缓冲体系的分别选择确定一种简便易行,效果良好的显色体系的组成成分,利用显色剂与不同浓度铁离子溶液进行显色反应制得标准色阶。将显色体系溶液喷涂到钢铁基材表面进行显色反应,对照标准色阶对钢铁锈蚀程度定量分析。  相似文献   

4.
本文在镍 ( )丁二酮肟—阿拉伯胶的显色体系中 ,引入二阶导数光谱——峰面积技术 ,对显色体系及测定方法进行了研究。该法有效消除 Fe ( )离子的干扰 ,提高了准确度和灵敏度。测定镍的线性范围为 0~ 12 mg/ L ,检出限 2 . 5 6μg/ L ,表观摩尔吸光系数ε=1. 4× 10 5L· mol-1 · cm-1 。用于中药材的加收试验 ,结果满意。  相似文献   

5.
本文研究了“碱土(Ⅱ)-稀土(Ⅲ)-茜紫-氯化+四烷基吡啶”共显色体系,确定了最佳显色条件。此共显色是形成杂多核配合物所引起。实验结果得出:参与共显色的金属离子半径比在此共显色效应中起着重要作用,其大小在一定范围内时,共显色强度基本相同,否则共显色强度就会减弱,甚至不发生;在固定显色剂的情况下,根据半径与半径比相近寻找新的共显色体系是有一定可能的,但不同的体系有不同的最佳半径比范围;金属离子水解能力的差别对此共显色体系影响不大。  相似文献   

6.
采用羧基化碳纳米管(Carboxylic CNTs)作为增效剂,以提高Cu2+-荧光酮(PF)-十六烷基三甲基溴化铵(CTMAB)络合显色体系的吸光度,并将其应用于对铜离子的检测中。研究了羧基化碳纳米管用量及分析试剂添加顺序对显色体系的吸光度的影响,并探讨了羧基化碳纳米管的显色增效机制。结果表明,羧基化碳纳米管的添加,最大吸收峰发生明显红移,有效提高了显色体系的吸光度;0.01%碳纳米管水溶液体积为0.5mL,添加顺序依次为Cu2+→PF→carboxylic CNTs,CTMAB时,显色体系吸光度最大,其值为0.399。  相似文献   

7.
根据国家药典委员会2010版药典品种对颗粒剂型增加溶出度检查的要求,对该品种的质量进行更有效的控制,建立琥乙红霉素颗粒的溶出度测定方法.对荷移比色法和硫酸显色法进行了比较,因硫酸显色法重现性和精密度好,灵敏度高,显色后溶液的稳定性强,显色剂易得等特点,仍沿用此方法.  相似文献   

8.
摘要 根据国家药典委员会2010版药典品种对颗粒剂型增加溶出度检查的要求,对该品种的质量进行更有效的控制,建立琥乙红霉素颗粒的溶出度测定方法。对荷移比色法和硫酸显色法进行了比较,因硫酸显色法重现性和精密度好,灵敏度高,显色后溶液的稳定性强,显色剂易得等特点,仍沿用此方法。  相似文献   

9.
本文提出一种修正的标准加入法用于干扰体系的分光光度定量分析。特点是仅取二个测量波长,即可同时获取待测组分及干扰组分的浓度,方法简单。利用此法对三个无机显色系统进行了分析。  相似文献   

10.
文献[1、2]曾报道了β-CD对显色体系的影响,但有机溶剂对于β-CD存在显色体系的影响至今未见报道。本文研究了乙醇存在下,锌与5-Br-PADAP-β-CD的显色反应。实验表明,乙醇对此显色反应有明显的增敏作用。形成络合物的适宜pH范围为7.5—10.5,络合物的最大吸收波长为552nm,表现摩尔吸光系数为1.35×10~5L·mol~(-1)·cm~(-2),较无乙醇存在的三元体系灵敏度增大了1.6倍。锌在0-16μg/25ml范围内服从比尔定律。显色体系在四小时内保持稳定。用该法测定了水样中微量锌,得到令人满意的结果。  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.
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