聚L-丝氨酸修饰电极循环伏安法测定肾上腺素

建立循环伏安法测定肾上腺素的新方法.制备聚L-丝氨酸修饰的化学修饰电极,用其测定了肾上腺素.结果表明,在pH5.0的磷酸盐缓冲溶液(PBS)中,扫描速率为140mV/s,循环扫描电位在0～0.6V时,肾上腺素在聚L-丝氨酸修饰玻碳电极上出现一对灵敏的氧化还原峰,峰电位为:Epa=0.364V,Epc=0.311V,ΔE=0.53V;测定肾上腺素的线性范围为5.0×10-7～2.0×10-4mol.L-1,方法检出限1.0×10-8mol.L-1.该方法简单、快速、灵敏、电极稳定性好,用于针剂中肾上腺素的测定,取得满意的结果.     

多巴胺在L-半胱氨酸修饰玻碳电极上的电化学行为及伏安测定

以L-半胱氨酸作为电极修饰剂,采用循环伏安法研究L-Cys/GC电极的制备和DA在该修饰电极的电化学行为及其测定.DA在pH=6.684的磷酸盐缓冲溶液中,在L-Cys/GC电极上产生一对灵敏的氧化还原峰,峰电位分别为Epa=0.180 V和Epc=0.125 V（vs.SCE）.同时用伏安法测定DA的线性范围为1×10-3～1.0×10-6 mol/L,检出限可低达1.0×10-7mol/L（S/N=3）.对1×10-4 mol/L DA平行测定50次,其相对标准偏差约为2.5%.该电极可望进一步发展为微电极,用于生物活体内的神经递质DA的实际检测.     

银/乙二胺修饰电极的制备及其对过氧化氢的催化

文章利用电聚合法制备出银/乙二胺修饰电极,并研究H2O2在该修饰电极上的电化学行为,并考察实验条件的影响.实验结果表明:在pH6.7的磷酸盐缓冲溶液中,银/乙二胺修饰电极对H2O2具有良好催化还原作用,H2O2在修饰电极上产生一对较好的氧化还原峰,峰电位分别为Epa=0.344 V,Epc=-0.215 V.线性范围为2.0×10-5～8.0×10-4 mol.L-1,检出限为1.0×10-6 mol.L-1.用于样品中H2O2的测定,结果满意.     

稀土-溴邻苯三酚红的极谱研究及应用

在pH =5 0 0的HAc NaAc介质中 ,溴邻苯三酚红 (简称BPR)在汞电极上产生 2个还原峰 ,峰电位分别为- 0 95V和 - 1 0 3V (vs SCE) .加入稀土离子时 ,2峰都降低 ,并且在 - 1 0 3V处的峰电流的降低与加入稀土离子的浓度在 9× 10 - 8～ 1× 10 - 5mol/L范围内呈线性关系 ,检测下限达到 5 8× 10 - 8mol/L .该波可成功地用于微量稀土的测定 .通过对电极反应机理的研究 ,可以确定该体系是一个反应物强吸附、配体 2电子还原的准可逆过程     

谷胱甘肽自组装膜修饰电极用于Cr(Ⅵ)离子的测定

将谷胱甘肽(GSH)自组装膜修饰电极用于Cr(Ⅵ)的测定.实验表明,在0.02mol/LH2SO4+0.1 mol/L NaNO3溶液中,在+1.00～-0.40V电位范围内进行循环伏安扫描,于+0.29V(Vs.SCE)处获得铬的还原峰信号、+0.65 V(Vs,SCE)处获得铬的氧化峰信号.Cr(Ⅵ)在GSH/Au修饰电极上的电化学行为比裸金电极有明显的改善,峰电流更为灵敏,且还原峰电流随着Cr(Ⅵ)浓度的增加而增大,因此选择+0.29V的还原峰作为分析信号,运用1.5次微分线性扫描伏安法对铬进行了定量分析,线性范围为1.0×10-8～1.0×10-6mol/L,检测限为1.0×10-9 mol/L.将所建立的方法应用于湖水样品中铬含量的测定,以ICP进行对照实验,结果满意.     

单扫描示波极谱法测定邻甲基苯甲酸中的邻苯二甲酸

建立了极谱测定邻甲基苯甲酸中邻苯二甲酸含量的方法。在 6.4× 1 0 -2 mol/L H3 PO4-KH2 PO4( p H 1 .82 )缓冲溶液中 ,邻苯二甲酸极谱催化氢波的峰电位 EP为 - 1 .32 V ( vs. SCE) ,其二阶导数峰峰电流 i″p 与邻苯二甲酸浓度在 5 .0× 1 0 -7～ 4.0× 1 0 -5mol/L和 4.0× 1 0 -5～ 2 .0× 1 0 -3mol/L范围内呈线性关系。1 0次测量 1 .0× 1 0 -5mol/L邻苯二甲酸还原波二阶导数峰峰电流 ,相对标准偏差 RSD为 1 .7% ,5 0 0 ( w/w)倍邻甲基苯甲酸不干扰测定邻苯二甲酸时。     

维生素B2在多壁碳纳米管修饰电极上的电化学行为及伏安测定

运用循环伏安法(CV)、线性扫描伏安法(LSV)等方法研究了维生素B2在多壁碳纳米管修饰电极上的电化学行为,建立了一种直接测定维生素B2的电化学分析方法.与裸玻碳电极相比,多壁碳纳米管修饰电极显示出很好的催化作用,维生素B2在修饰电极上得到一对灵敏的氧化还原峰(Epa=-0.222 V,Epc=-0.317 V),且氧化还原峰电流显著增强.在优化实验条件下,还原峰电流与维生素B2浓度在3.0×10-6～2.0×10-5 mol·L-1有良好的线性关系,检出限为1.0×10-6 mol·L-1.对1.0×10-5 mol·L-1维生素B2溶液平行测定10次的相对标准偏差(RSD)为4.2%.用此方法测定了维生素B2片中维生素B2的含量,结果满意.     

多巴胺在L-半胱氨酸修饰玻碳电极上的电化学行为及伏安测定

以L-半胱氨酸作为电极修饰剂,采用循环伏安法研究L-Cys/GC电极的制备和DA在该修饰电极的电化学行为及其测定.DA在pH=6.684的磷酸盐缓冲溶液中,在L-Cys/GC电极上产生一对灵敏的氧化还原峰,峰电位分别为Epa=0.180 V和Epc=0.125 V（vs.SCE）.同时用伏安法测定DA的线性范围为1×1...     

银掺杂聚L-苏氨酸修饰电极的制备及对多巴胺的测定

利用循环伏安法,研究了银和L-苏氨酸在玻碳电极表面电化学聚合的条件,制备了银掺杂聚L-苏氨酸修饰电极。并研究了多巴胺在修饰电极上的电化学行为,建立了测定多巴胺的新方法。在pH=6.5磷酸盐缓冲溶液中,扫描速率为20mV/s,多巴胺在修饰电极上产生一对明显的氧化还原峰,峰电位分别为Epa=0.218V,Epc=0.189V。用示差脉冲伏安法测定时,峰电流与多巴胺浓度分别在8.00×10-7～1.00×10-5和1.00×10-5～1.00×10-4mol/L范围内呈良好的线性关系,检出限为1.0×10-7mol/L。用于药物中多巴胺的测定,结果满意。     

银掺杂聚L-天冬氨酸修饰电极测定对氨基苯酚

利用循环伏安法制备银掺杂聚L-天冬氨酸化学修饰电极.用循环伏安法研究对氨基苯酚在该电极上的电化学行为,建立测定对氨基苯酚的新方法.在pH=5.5的磷酸盐缓冲溶液中,对氨基苯酚在银掺杂聚L-天冬氨酸修饰电极上产生一对灵敏的氧化还原峰,峰电位分别为Epa=203 mV,Epc=129 mV(相对Ag/AgCl电极).用循环伏安法(CV)进行测定,氧化峰峰电流与对氨基苯酚的浓度分别在8.00×10-7～1.00×10-4 mol/L和1.00×10-4～5.00×10-4 mol/L范围内呈线性,检出限为1.0×10-7 mol/L.对5.0×10-5 mol/L对氨基苯酚溶液平行测30次,其相对标准偏差为6.9%,用于废水中对氨基苯酚的测定,结果满意.     

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.     

Features of Women's language

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.     

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     

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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