电沉积咖啡酸玻碳修饰电极对抗坏血酸的催化氧化

在pH=7.0的磷酸缓冲溶液中采用电沉积技术将咖啡酸修饰于玻碳电极表面制备了一层稳定的薄膜,该修饰电极制备简单,稳定性良好.用循环伏安法研究了抗坏血酸在修饰电极上的电化学行为,其氧化峰电流与抗坏血酸的浓度和pH值有关,当pH值达到7.7时,抗坏血酸在修饰电极上的氧化峰电流最大,氧化峰电流与抗坏血酸浓度在4.0×10-5～2.0×10-2mol/L范围成良好的线性关系,检测限为1.0×10-5mol/L,方法简单、快速、准确,可应用于抗坏血酸药片的检测.     

多巴胺在聚L-天冬氨酸修饰电极上的催化氧化及测定

研究了聚L_天冬氨酸修饰电极的制备及其电化学性质。实验表明 ,该修饰电极对神经递质多巴胺的电化学氧化有显著的催化作用 ,使电极反应过程的可逆性变好 ,峰电流明显增大。采用差示脉冲伏安法对多巴胺进行定量分析 ,线性范围为 1 0× 10 - 7～ 1 0× 10 - 4 mol L ,检出限为 5 0× 10 - 8mol L。该聚合物修饰电极具有良好的选择性 ,能有效地排除抗坏血酸对测定的影响 ,用于合成样品分析 ,结果令人满意。     

多巴胺在纳米金修饰微玻碳电极上的电化学行为研究

用电沉积的方式制备了纳米金修饰微玻碳电极 ,该修饰电极能分开多巴胺和抗坏血酸的氧化峰 .研究了溶液pH值、磷酸缓冲溶液浓度对多巴胺电化学行为的影响 .多巴胺氧化峰电流值与其浓度在 5× 10 - 6～ 1× 10 - 4mol/L范围内成线性关系 .     

多巴胺在聚磺基水杨酸修饰电极上的电化学测定

研究了聚磺基水杨酸修饰玻碳电极的制备及多巴胺在此修饰电极上的电化学行为.在磷酸盐缓冲溶液中,多巴胺在修饰电极上呈现两个还原峰和两个氧化峰.其峰电位随着pH的增加而负移.多巴胺的氧化峰电流与其浓度分段呈线性关系:在3×10-7～9×10-6mol/L浓度范围内,其回归方程为ipa (10μA) = 0.23548 0.30552c(mol/L),相关系数r=0.9930;在10-5-10-4mol/L浓度范围内,其回归方程为ipa(10μA) =2.35604 0.0685c (mol/L), 相关系数r=0.9913.检出限为3.0×10-7mol/L.实验结果表明:该修饰电极能有效消除抗坏血酸的干扰,用于注射液中多巴胺的检测,其回收率在97.7%-101.6%范围内.     

聚甲基红膜修饰电极对儿茶酚的测定

用电化学方法制备了聚甲基红膜修饰电极,该电极对儿茶酚有明显的电催化作用,其氧化峰电位负移70mV,峰电流显著增加,儿茶酚的氧化峰电流在2 0×10-6～1 0×10-4mol/L范围内与其浓度成线性关系,该电极性能稳定,重现性好.     

聚组氨酸修饰电极测定多巴胺的研究

本文研究了多巴胺在聚组氨酸修饰电极上的循环伏安行为.在pH7.0的磷酸盐缓冲溶液中,用线形扫描伏安法测定多巴胺的线性范围为:6.0×10-8～1.0×10-5mol/L,1.5×10-5～1.0×10-3mol/L,检出限为4×10-8mol/L.用于药剂中多巴胺的测定,结果满意.     

抗坏血酸在半胱氨酸自组装膜上的电化学行为及应用

半胱氨酸自组装修饰金修饰电极对抗坏血酸(Vc)具有很高的电催化氧化活性.在pH 2.0的0.1 mol/L缓冲溶液中,可得到一对准可逆的氧化还原峰.电极反应受扩散控制.氧化峰电流与抗坏血酸浓度在5.0×10-6～1.1×10-3 mol/L范围内成线性关系,检测限为1.0×10-6 mol/L.该分析方法应用于果汁中的抗坏血酸分析,结果令人满意.     

多壁碳纳米管-[BMIM]PF_6修饰电极测定Hg~(2+)

制备了多壁碳纳米管(MWCNT)-离子液体([BMIM]PF6)修饰电极并作为工作电极,采用阳极溶出伏安法检测Hg2+。研究表明,Hg2+在修饰电极上可得到灵敏的溶出峰。考察了实验条件对Hg2+在该修饰电极上溶出伏安行为的影响。在优化的实验条件下,Hg2+在1.0×10-6mol/L～1.0×10-4mol/L浓度范围内与其溶出峰电流呈良好的线性关系,相关系数为0.9992,检出限为1.0×10-7mol/L。该修饰电极制备简单,用于微量汞的检测,效果良好。     

聚对氨基苯甲酸修饰电极测定药剂中的多巴胺

本文研究了聚对氨基苯甲酸修饰玻碳电极的制备及多巴胺在此修饰电极上的电化学行为。在pH为7．5的磷酸盐缓冲溶液中,多巴胺在此修饰电极上呈现三个峰,两个还原峰和一个氧化峰,其峰电位随着pH的增加而负移。多巴胺浓度在3．0×10~(-6)～8．0×10~(-4)mol/L的范围内与其氧化峰电流呈线性关系,回归方程为i_p(10μA)=0．92023 0．36264c(mol/L),相关系数r=0．9925,检出限为2．0×10~(-8)mol/L。实验结果表明：该修饰电极能有效消除抗坏血酸的干扰,方法用于注射液中多巴胺的检测,其回收率在98．9%～100．5%范围内。     

单壁碳纳米管化学修饰电极的制备及其测定鸟瞟呤的研究

报告了一种制备单壁碳纳米管化学修饰电极的方法,并研究了鸟嘌呤在此修饰电极上的电化学行为.鸟嘌呤在单壁碳纳米管修饰玻碳电极上出现一个灵敏的氧化峰,峰电流位于0.64V(vs.SCE).与裸玻碳电极相比,单壁碳纳米管修饰电极显著提高鸟嘌呤的氧化峰电流.优化了各项测定参数,建立了一种直接测定鸟嘌呤的电分析方法.氧化峰电流与鸟嘌呤的浓度在5×10～8-2 × 10-5mol/L之间有很好的线性关系,开路富集3min,检出限为2×10～8mol/L.该方法检测限低、分析速度快、重现性好、准确可靠.     

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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