利用壳聚糖碳糊修饰电极测定碘

应用组合法将壳聚糖、石墨粉以及石蜡油按一定比例调和制成壳聚糖碳糊修饰电极,该修饰电极对I-的电极反应具有良好的促进作用.详细研究了I-在该修饰电极上的阳极溶出伏安特性,并对相关机理进行了探讨.实验表明,修饰电极在pH为4.5的0.1 mol/LKCl溶液中对I-具有良好的吸附性和选择性,电极响应灵敏.其阳极溶出峰电流在5.0×10-6 mol/L～2.0×10-3 mol/L I-浓度范围内呈良好线性关系,检出下限达2.0×10-7 mol/L.将该法应用于碘酒中碘含量的测定,取得较好的结果,7次平行样品分析结果的相对标准偏差为4.3%,样品回收率范围为94.5%～100.2%.     

壳聚糖金属复合物修饰电极制备及其在过氧化氢电化学检测中的应用

原位制备了羧甲基壳聚糖/铜复合物修饰电极、羧甲基壳聚糖/银复合物修饰电极和壳聚糖/聚苯胺/钯复合物修饰电极,金属粒子均匀分散于聚合物薄膜中.3种修饰电极对H2O2 均表现出了良好的检测性能,它们对H2O2的线性响应范围依次为1.0μmol/L～10.0 mmol/L,10μmol/L-6.0 mmol/L和10μmol...     

聚苏木精/氧化石墨烯修饰玻碳电极测定水样中痕量铅和镉

将玻碳电极用氧化石墨烯修饰后电聚合上苏木精聚合膜,利用该修饰电极差分脉冲溶出伏安法同时测定铅和镉.对支持电解质及其缓冲溶液、富集电位及富集时间测定条件进行了优化.在0.1 mol/L pH 3.5的NaAc-HAc缓冲液中,以此修饰电极为工作电极,在-1.1 V处搅拌富集220 s,用差分脉冲伏安法分别测定-0.58 V和-0.8V处的氧化峰电流.结果表明,该电极显著提高了铅和镉的电化学响应信号.在优化条件下,峰电流与铅和镉的浓度在0.01~1μmol/L范围内呈良好的线性关系,相关系数为0.991~0.995.检出限分别为8 nmol/L(Pb2+)和1 nmol/L(Cd2+)(S/N=3).将该法用于实际水样中痕量铅和镉的测定,回收率为92.2%~105.8%.     

聚苯胺/氯化银复合材料修饰电极测定铅(Ⅱ)

制备了聚苯胺/氯化银修饰的玻碳电极(PANI/Ag Cl/GCE),并用于检测铅离子。结果表明:铅离子在修饰电极上具有良好的电化学响应,用差分脉冲溶出伏安法可对Pb2+进行灵敏检测。研究了p H值、沉积电位和时间等因素对铅离子响应信号的影响。在最佳测定条件下,在0.5~70 nmol/L范围内,铅离子浓度与电化学信号呈线性变化关系,检出限为0.1 nmol/L,回收率在97.9%~100.7%之间,RSD为2.7%~5.4%。本方法简捷、快速灵敏,适于痕量铅含量测定。     

聚谷氨酸/多壁碳纳米管修饰玻碳电极测定扑热息痛

将聚谷氨酸和多壁碳纳米管修饰到玻碳电极表面制成了一种新型的电化学传感器,用于扑热息痛测定.研究了扑热息痛在修饰电极上的电化学行为.结果表明,在0.1 mol/L磷酸盐缓冲溶液中(pH7.0),修饰电极显著提高了扑热息痛电化学响应信号.在2.0×10-7⁶.0×10-5mol/L浓度范围内扑热息痛的浓度在该电极上与电化学响应信号呈良好的线性关系.信噪比为3时,检出限为2.0×10-8mol/L.将该方法用于药品中扑热息痛的测定,回收率为92.4%6.0×10-5mol/L浓度范围内扑热息痛的浓度在该电极上与电化学响应信号呈良好的线性关系.信噪比为3时,检出限为2.0×10-8mol/L.将该方法用于药品中扑热息痛的测定,回收率为92.4%¹03.1%.     

基于石墨烯-壳聚糖/纳米金的酪蛋白电化学免疫传感器

将石墨烯和壳聚糖的复合物滴涂到玻碳电极表面,利用壳聚糖对纳米金的吸附将其修饰到上述电极,以纳米金对抗体的良好亲和力将酪蛋白抗体修饰到电极表面制成免疫传感器,利用循环伏安法对传感器进行表征.结果表明,石墨烯和纳米金有效地促进了电子的传递速度,提高了检测灵敏度.在优化条件下,响应电流与酪蛋白浓度的对数在10～10 000μg/L范围内呈良好的线性关系,检出限为2μg/L(S/N=3).     

铁氰化钴/铁复合膜修饰电极的制备及应用

采用电化学方法制备了铁氰化钴/铁(Fe/CoHCF)复合膜修饰电极,研究了该修饰电极的电化学性质及其电催化活性,实验表明该复合物不是铁氰化钴与普鲁士蓝(PB)的简单混合物,而是钴、铁共沉积形成的多核铁氰化物.该修饰电极对H2O2具有良好的电化学响应,安培法测定H2O2的线性范围为5.0×10 7～3.7×10 3mol.L 1,检测限(3sb,n=11)为2.0×10 7mol.L 1,灵敏度为44.5μA.(mmol.L 1)1.该法已用于模拟水样中H2O2含量的测定,结果满意.     

石墨烯/离子液体/壳聚糖/血红蛋白修饰玻碳电极检测过氧化氢

将石墨烯、离子液体(1-丁基-3-甲基-咪唑四氟硼酸盐)与壳聚糖结合,制备了一种新型的石墨烯-离子液体/壳聚糖纳米复合膜修饰玻碳电极.用循环伏安法研究了血红蛋白在该修饰电极上的直接电化学行为.结果表明,血红蛋白在该纳米复合膜电极上对过氧化氢具有良好的催化性能.过氧化氢的电流响应信号与其浓度在0.1～500μmol/L范围内呈线性关系,检出限为0.02μmol/L(RSN=3),为过氧化氢检测提供了一种灵敏的新方法.     

壳聚糖-碳纳米管复合物修饰的过氧化氢生物传感器

以玻碳电极为基底,将壳聚糖-碳纳米管（CS-MWNT）复合物修饰于电极表面,然后利用氯金酸电沉积纳米金（nano-Au）,最后吸附过氧化物酶（HRP）,从而制备出性能良好的HRP/nano-Au/CS-MWNT/GCE过氧化氢生物传感器.用循环伏安法和计时电流法考察该修饰电极的电化学特性,发现该修饰电极对过氧化氢（H2O2）的还原有良好的电催化作用.实验结果表明：该传感器在7.0×10^-6mol/L-1.29×10^-2mol/L范围内对H2O2有良好的线性响应,线性相关系数R=0.9989,检测下限为2.3×10^-6mol/L（S/N=3）.此外,该传感器还具有较快的响应速率、较好的稳定性和重现性.     

铋膜修饰碳离子液体糊电极测定痕量铅离子的研究

将疏水性离子液体N-己基吡啶六氟磷酸盐作为粘合剂和修饰剂,与碳粉混合,然后压制到电极管中制备出一种碳离子液体糊电极(CILE).用预镀铋膜法将铋离子沉积在CILE表面制备的铋膜修饰电极(Bi/CILE)作为工作电极,利用阳极溶出伏安法测定痕量铅离子.在p H 5.0的HAcNa Ac缓冲溶液中,当富集电位为-1.4 V,富集时间为300 s,铅离子有一个灵敏的阳极溶出伏安峰,峰电位为-0.457 V(vs.SCE),在8.0×10-8mol/L~4.0×10-5mol/L浓度范围内,氧化溶出峰电流与Pb(II)的浓度呈很好的线性关系,检出限为2.05×10-8mol/L,重现性良好,并将该方法成功用于生活自来水样中铅离子含量的测定.     

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     

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