枇杷花茶中微量元素的溶出特性研究

采用微波消解-火焰原子吸收光谱法测定了枇杷花茶中微量元素钙、铁、锰、镁、锌、镍和铜的含量,并对枇杷花茶进行不同浸泡时间和不同浸泡次数微量元素溶出研究。结果表明,枇杷花茶中微量元素丰富,含量顺序为:钙铁锰镁锌镍铜。溶出特性研究表明,钙和镁最易溶出,而铁和锰较不容易溶出,微量元素的溶出量与浸泡时间呈现良好对数关系,单泡微量元素的溶出量与冲泡次数呈负指数关系。研究表明,采用微波消解-火焰原子吸收光谱法测定枇杷花茶中钙、铁等元素含量方法简便、准确、灵敏,适合常规分析;枇杷花茶最佳饮用条件为浸泡时间30 min,浸泡次数为3次。     

微分脉冲阳极溶出伏安法连续测定葛花中微量锌、铜

微分脉冲阳极溶出伏安法测定葛花中微量锌和铜.在0.01mol/L的高氯酸溶液中,锌、铜均有良好的溶出峰.测定结果与原子吸收光谱法以及光度法相符.方法简便、反应灵敏、准确度高.Zn2+在0～0.8ug/ml、Cu2+在0～0.4ug/ml分别与其溶出峰电流呈良好的线性关系.     

玻碳电极示波极谱阳极溶出法测定三氯化金中痕量铜铅

用示波极谱阳极溶出法作三氯化金试剂(分析纯)中痕量铜铅的定量测定,以玻璃碳电极为工作电极。用环戊醇苹取试样水溶液中的大量基体元素Au~(3+),用还原剂还原剩余在水相中的少量 Au~(3+),在 pH=3.3的 HCl 介质中,作阳极溶出测定铜,富积电位-0.6伏(VS.SCE,下同),富积时间2分钟,铜溶出峰电位-0.11伏。测完铜后,用双硫腙-四氯化碳革取掉铜,剩余水相作阳极溶出测定铅,富积电位-1.5伏,富积时间2分钟,铅溶出峰电位-0.55伏。本方法可测至1ppb 的铜和10ppb 的铅,两者回收率平均误差分别为+4%和-7%。     

微分脉冲阳极溶出伏安法测定铝土矿中镓

在ＰＨ３的盐酸介质中，Ｇａ与邻苯二酚形成络合物。用微分脉冲阳极溶出伏安法测定，在－０．６９伏特出现阳极溶出峰。在－１．５伏特下电解富集９０秒，用微分脉冲溶出伏安法测定铝土矿中向量镓。     

微分脉冲阳极溶出伏安法连续测定葛花中策量锌,铜

微分脉冲阳极溶出伏安法测定葛花中微量锌和铜,在０．０１ｍｏｌ／Ｌ的高氯酸溶液中,锌、铜的有良好的溶出峰。测定结果与原子吸收光谱法以及光度法相符,方法简便、反应灵敏、准确度高。Ｚｎ＾２＋在０～０．８ｕｇ／ｍｌ、Ｃｕ＾２＋在０～０．４ｕｇ／ｍｌ分别与其溶出身电流呈良好的线性关系。     

玻璃碳电极同位镀汞阳极溶出伏安法同时测定铜、铅、镉、锌的可能性

本文用线性扫描阳极溶出伏安法(ASV)和微分脉冲阳极溶出伏安法(DPS)研究了在同位镀汞玻璃碳电极上同时测定铜、铅、镉、锌的可能性。实验证明同时测定这些离子的困难在于汞齐中形成金属间的化合物;干扰主要取决于铜和辞在汞齐中的相互作用;对一般未污染的环境样品用ASV或DPS同时测定铜、铅、镉或锌、铅、镉不会产生固难;用ASV同时测定铜、铅、镉、锌时在铜的溶出峰前出现一个铜辞化合物中辞的溶出峰,按本文所提出的测量峰电流的方法可以同时测定上述四种离子;用DPS可以用较短的富集时间同时测定这些离子。所制定的方法应用于鉴定蒸馏水及饮用水质量发现,由电加热蒸馏水器得到的蒸馏水会带来铜、铅的污染;济南地区各自来水厂水源中上述离子的含量大大低于国家规定的生活饮用水质标准。     

金电极二次导数阳极溶出伏安法测定尿铜

本文提出了金电极二次导数阳极溶出伏安法测定尿铜的方法。H2SO4-KMnO4为尿液的消化剂,水浴90℃消化1.5小时后,过量KMnO4用H2O2还原。低于20ppbCu2+浓度和铜溶出峰高成线性关系,检出限为0.4ppb。测定一5ppbCu2+时的相对标准偏差为3.2%。测它10ppbCu2+时的回收率为96—105%。PO4a-浓度比正常值高限浓度高一倍时对尿铜测定有干扰,但其它常见无机离子浓度达到两倍正常值高限浓度均不干扰。     

饮料中铜含量的二次微分电位溶出测定方法

建立了二次微分电位溶出法分析测定饮料中铜含量的新方法,优化了试验条件,如pH值、电沉积电位、平衡电位等.实验表明,铜的线性测定范围为0~1600 ng,相关系数r=0.997 6,铜的检出限为0.85 ng/mL.该法测定饮料中铜含量的结果与石墨原子吸收法无显著差异.     

铜质火锅使用过程中的金属元素含量分析

探讨酸菜在铜质容器中熬煮,砷、汞、铅、镉、铬、镍、铜等元素含量的变化.以微波消解预处理样品,运用ICP-MS、HG-AFS法测定铜锅熬煮酸菜过程中汤料、酸菜中重金属元素的含量变化.在紫铜锅中熬煮酸菜6 h,可使锅体汞、铅、铜溶出较多,镉、铬、镍少量溶出,基本无砷溶出.其中,汤料中汞、铅、铜、镉、铬和镍分别约增加914%、65%、513倍、55%、46%和60%,酸菜中汞、铅、铜、镉、铬和镍分别增加81%、159%、375倍、19%、142%和70%.从健康角度出发,紫铜锅可能不适宜作酸菜类火锅的烹饪容器.     

巯基棉富集-计时电位溶出法连续测定汞、铋、铜、铅和镉

研究巯基棉的快速制备新技术及汞铋、铜、铅、镉5种离子同时在巯基棉上富集和洗脱条件。洗脱液中的离子采用计时电位溶出法测定,摸索出消除汞,铜记忆效应的方法,使测定重现性良好。5种离子的回收率在90％～110％之间。     

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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