4-(邻-重氮氨基苯胂酸)-偶氮苯的合成及与Hg~(2+)的显色反应的研究

本文叙述了4-(邻-重氮氨基苯胂酸)-偶氮苯的合成方法,分析化学性质及与Hg~(2+)的显色反应。探讨了该试剂与Hg~(2+)_生成络合物的适宜条件,在氢氧化钠介质中,Hg~(2+)与该试剂生成橙色络合物,最大吸收峰位于500nm处,0～10.0μgHg~(2+)/ml符合比耳定律,摩尔吸光系数为1.5×10~5升、摩尔~(-1)、厘米~(-1)。试剂用于被污染的珍珠粉中汞的测定,得到满意的结果。对样品进行9次平行测试,其变异系数为5.7%,加入标准汞的回收率为93—110%。微量汞的测试方法常用的有双硫腙比色法,原子吸收分光光度法,及动力学法等。     

新试剂APNBT与汞的显色反应研究(英文)

研究新试APNBT课题与汞显色反应的最佳条件,在TrtonX—100存在下,pHl0.4～12.0范围内汞(Ⅱ)与试剂形成黄色配合物,组成为1:2,最大吸收波长为450nm,ε’为8.88×10~4L·mol~(-1)·cm~(-1),在535nm处,试剂的吸收与配合物的吸收差值最大,ε’为1.18×10~5L·mol~(-1)·cm~(-1),线性范围0～20μgHg(Ⅱ)/25mL,以双硫腙萃取汞(Ⅱ),分离干扰元素,成功地测定了合成试样和天然水中的汞,加入回收率为96％～102％。     

新试剂邻氯间硝基苯基重氮氨基-4-苯基-2-噻唑的合成及其与汞显色反应的研究

本文报道了新试剂邻氯间硝基苯基重氮氨基-4-苯基-2-噻唑的合成及其与汞的显色反应,在混合表面活性剂TritonX-100-CTB存在下,于pH9.2的Na2B4O7-NaOH缓冲溶液中,试剂与汞生成2：1紫色配合物,其最大吸收波长位于590nm处,表观摩尔吸光系数为65×104L·mol-1·cm-1,汞量在0～20μg／25ml范围内符合比尔定律．方法用于合成水样及废水中微量汞的测定,结果满意．     

一种西夫碱化合物的合成及其在汞测定中的应用

合成一种新西夫碱2-氨基-5-巯基-1,3,4-噻二唑水杨亚胺(MTYMP),用常规法对其结构进行表征.该化合物在300 nm激发下,在410 nm处有强荧光峰,与汞离子可形成稳定的配合物而使其荧光猝灭.据此,该化合物可作为测定汞的荧光试剂,建立一个荧光猝灭测定微量汞的新方法,汞离子的含量在4.0~100.0μg·L-1范围内与试剂的荧光熄灭值呈线性关系,方法的检出限为0.315μg·L-1.该方法应用于废水中微量汞的测定,结果满意.     

新显色剂2,4-二氯苯基荧光酮分光光度法测定钛的研究及应用

研究了钛-2,4-二氯苯基荧光酮(DClPF)-吐温-40三元络合物的显色反应条件及应用.结果表明,在0.02～0.11mol·L-1的硫酸介质中,在Tween-40存在下,Ti( )与试剂形成1∶4的红色络合物.最大吸收在542nm波长处,表观摩尔吸光系数为2.10×105L·mol-1·cm-1,钛含量在0～14μg/25ml范围符合比耳定律,方法灵敏,选择性较高,操作简便,在掩蔽剂存在下,可不经分离直接测定合金钢标准样品中的微量钛,结果满意.     

微波消解-氢化物发生-原子荧光光谱法同时测定食品中的As和Hg

应用微波消解-氢化物发生-原子荧光光谱法测定食品中微量砷(As)和汞(Hg)的含量,实验结果表明,在最佳条件下,该法的回收率分别是:砷为94.5%～101%,汞为92%～96%,相对标准偏差值为1.0%～1.66%,As和Hg的检出限分别为0.1μg·L-1和0.02μg·L-1,其线性范围分别为1.0～100μg·L-1和0.2～60μg·L-1.该法能满足各类食品中微量砷和汞含量的测定要求,具有分析速度快、操作简便、检验效率高等特点.     

5′—硝基水杨基荧光酮—N—氯化十六烷基吡啶分光光度法测定微量铜

详细研究了 5′-硝基水杨基荧光酮 -CPC与铜形成三元络合物的显色反应条件和光度性质 ,结果表明 :在 p H6.55的缓冲溶液中 ,铜与试剂形成三元络合物 ,其最大波长在 563 nm,表观摩尔吸光系数为 1 .3 6× 1 0 5L· m ol-1· cm-1,铜含量在 0～ 7μg/2 5ml范围内符合比耳定律 ,本法通过巯基棉分离 ,测定了环境水样中铜的含量 ,结果较好     

镉（Ⅱ）—铜铁试剂络合吸附波及其应用研究

研究了镉(Ⅱ)-铜铁试剂络合物的伏安行为,在0.15mol·L~(-1)NH_4Ac(pH6.7)、0.5 mmol·L~(-1)Cup溶液中,用单扫示波极谱得到一灵敏的Cd(Ⅱ)-Cup络合吸附波。峰电位E_P=-0.69 V(vs.SCE),峰电流与镉(Ⅱ)浓度在0.01～1.5μmol·L~(-1)范围内成正比,检出限为5.0mol·L~(-1)。用等摩尔系列法测得络合物的络合比为1:2,表观稳定常数为6.1×10~(11)。用线性扫描和循环伏安法、常规脉冲极谱等手段研究络合物电极反应机理。实验表明,该体系为可逆吸附波。     

新显色剂偶氮硝膦Ⅰ(NPA-Ⅰ)的研究(1)——光度法测定镁

新显色剂偶氮硝膦I[2-(4-硝基-2-膦酸苯偶氮)-1,8-二羟基-3,6-萘二磺酸]能在硼砂氢氧化钠体系中,pH8.6～9.35范围内与镁迅速发色,形成兰色络合物.络合物至少稳定8小时.该络合物具有高的灵敏度(ε_(580)=3.85×10~4l·mol~(-1)cm~(-1))、较宽的比耳定律范围(0～30μgMg/25 ml).用等克分子连续变更法及摩尔比法测得络合物组成为R∶Mg=1∶1. 由于显色反应中共存离子干扰较小,并允许一定量的掩蔽剂(如三乙醇胺、邻菲罗啉等)存在,故该试剂的选择性较其它同类试剂为优. 本文报导了用NPA-I不经分离测定微量镁简单、迅速、准确的方法.分析结果证明,本法用于某些球墨铸铁和稀土-硅-镁中间合金,取得了满意的结果.     

改性绿茶对汞的吸附作用

采用原子吸收光谱法研究有机汞和无机汞的吸附作用。改性绿茶的用量为 2 5 mg、在 p H值 =7的溶液中搅拌 6 min,无机汞的吸附率达 95 % ,有机汞的吸附率不大于 5 % ;同等量的改性绿茶在 p H值 =1的溶液中搅拌9min,有机汞的吸附率可达到 90 %以上。 10次重复分离测定 0 .1μg· ml- 1汞溶液 ,测得无机汞、有机汞的检出限分别为 0 .0 6μg· L- 1 和 0 .0 8μg· L- 1 ,相对标准偏差为 8.6 %和 5 .8% ,回收率为 92 .5 %～ 10 5 .3%和 93.8%～ 10 6 .6 %。实验还表明 ,在盐酸浓度分别为 2 .0 mol· L- 1、6 min和 4 .0 mol· L- 1、11min,共存 KCl的量为 10 0mg,可定量解吸无机汞和有机汞     

Markedness and its Interpretation in Language Use

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.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

Achieving Unusual States of Matter Under High Pressure

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-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

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     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

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     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

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     

Call for Papers

<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     

Journal of Donghua University ( English Edition) Contents of Volume 31

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