多相催化氧化降解苯酚过程的研究

利用紫外可见光谱和高效液相色谱研究了催化氧化降解苯酚的过程.结果表明,非晶铁氧化物催化剂在催化氧化降解苯酚时具有较高的催化活性,苯酚降解的中间产物有:对苯二酚、邻苯二酚、苯醌和低级脂肪酸,其降解机理是羟基自由基攻击苯环上OH的邻位或对位而使苯环开环,生成低级脂肪酸,并最终转化成二氧化碳和水,从而使苯酚得以降解.     

普施安红MX-5B的电子束辐照降解

普施安红(Procion Red, PR)MX-5B是一种活性单偶氮染料, 在其生产和使用的过程中会产生采用传统的生化处理技术很难处理的染料废水. 运用电子束辐照技术处理普施安红MX-5B模拟染料废水, 研究了辐照剂量、初始浓度、初始pH值和不同气氛条件等因素对处理效果的影响. 实验结果表明, 上述因素对普施安红MX-5B的降解有着显著影响. 在氛围不同的情况下, 普施安红MX-5B的降解率为饱和氧羟基自由基氧化体系>饱和空气氧化还原体系>饱和氮气水合电子还原体系. 在羟基自由基氧化体系中, 羟基自由基攻击偶氮双键(-N=N-)和苯环导致分子断裂生成的中间产物苯胺, 被进一步降解为小分子有机酸.     

羟基自由基与典型苯系物的后续反应机理研究

为了研究大气中羟基自由基(·OH)氧化降解典型苯系物的反应机理.本文采用MPWB1K计算方法,理论上预测·OH与3种苯系物(苯、甲苯和对二甲苯)的反应过程,并全面地考虑了苯与·OH反应生成的加成和脱氢产物在大气中可能进行的后续反应机理及氧化降解产物.结果表明:·OH与苯、甲苯及对二甲苯的加成反应均比氢原子提取过程更容易...     

基于Fenton反应的羟基自由基对胶原蛋白的氧化降解作用

研究了Fenton反应产生的羟基自由基对Ⅰ型胶原蛋白的降解作用。单独的过氧化氢(H2O2),Fe2+以及超氧阴离子自由基(O2-·)均对胶原蛋白无降解作用。但是,在经过氧化氢和Fe2+构成的Fenton反应产生羟基自由基后,胶原蛋白发生了降解。胶原蛋白的降解作用随着羟基自由基的增加(H2O2+Fe2+浓度增加)而加强。但羟基自由基的生成是瞬间完成的,其对胶原蛋白的降解作用随着H2O2和Fe2+反应时间的延长而降低。     

具有纳米结构的TiO2纤维光催化氧化活性

研究了具有纳米结构,高比表面的锐钛矿TiO2纤维在光催化降解苯酚体系中的氧化性能,发现其活性与P25相当;通过加羟基自由基猝灭剂证实了羟基自由基(HO·)对苯酚降解的贡献;而通过加空穴猝灭剂则观察到明显的空穴(h+)效应.并通过KI氧化反应进一步研究了催化剂表面上的空穴效应,结果表明,TiO2纤维上的光生空穴比P25稳定,其空穴量子产率是后者的3.3倍.     

自由基降解甲基橙溶液试验

针对含有偶氮类难降解有机物的染料废水具有色度大,生物可降解性低,难于处理等特点,模拟了有典型偶氮结构的甲基橙染料废水,对强电离放电产生的自由基溶液降解甲基橙进行了研究,讨论了pH值、甲基橙溶液初始质量浓度、自由基溶液质量浓度、温度以及反应时间等因素对甲基橙溶液降解性能的影响.结果表明,酸性条件有利于甲基橙溶液的降解,pH=1.5时,自由基氧化降解200 mg/L的甲基橙溶液3 min后,其COD的去除率和脱色率最大值分别达到86.87%和88.53%.对比甲基橙溶液处理前后紫外-可见光谱图的变化,发现经自由基降解后,偶氮键及苯环都受到破坏,大部分甲基橙分子已经氧化分解.     

TiO2纳米晶表面羟基自由基的生成对光催化性能的影响

采用溶胶-凝胶法制备纳米TiO2.用X射线衍射谱(XRD)测定了TiO2粒子的晶相结构;以对苯二甲酸作为探针分子,结合化学荧光技术研究了TiO2表面羟基自由基的生成;以降解罗丹明B(RhB)为模型反应,考察了TiO2粒子的光催化活性.结果表明,TiO2粒子的晶相结构对其羟基自由基的生成和光催化活性产生显著影响;羟基自由基的生成速率越大,光催化活性越高.     

·OH氧化降解高质量浓度苯酚废水的研究

利用气体放电协同高效混溶技术制取羟基自由基溶液,进行初始质量浓度为8853 mg/L的苯酚废水溶液氧化处理实验.羟基自由基质量浓度从0增加到1700 mg/L时,苯酚去除率为48.43%,在这一范围内,除去1 g苯酚需羟基自由基0.37 g.叙述并解释了废水pH值和电导率与羟基自由基质量浓度之间的变化关系.随着羟基自由基质量浓度的增加,废水酸碱性由接近中性逐渐转为酸性,质量浓度越大,酸性越强,而电导率先减小后增大.结合降解中间体产物和实验现象,对羟基自由基氧化降解苯酚过程进行了分析.     

高铁酸钾降解苯胺的效能与机理

采用次氯酸钾法制备高铁酸钾,并用于降解水中的苯胺.通过对比试验证明高铁酸钾对苯胺的去除效果远优于单用三氯化铁絮凝剂及次氯酸钾氧化剂,其最佳反应条件为:在高铁酸钾投量与苯胺的摩尔比为1∶1,pH值=3.0～9.0,反应时间为20min的条件下,苯胺的去除率可达80%以上.根据高铁酸钾降解苯胺的产物光谱分析可知,高铁酸根首先对苯环上的NH2发起攻击,通过一系列反应生成偶氮苯等中间产物,这些中间产物有一部分可被开环并继续被氧化成为烷烃及烯烃等脂肪烃,但反应后残余的偶氮苯等中间产物依然是微生物难降解物质.高铁酸钾应用于难降解苯胺废水生物处理的预处理,可以有效去除废水中苯胺,并在一定程度上改善苯胺废水的可生化性.     

溴甲酚绿测定Fenton产生的羟基自由基

利用Fenton反应产生的羟基自由基与染料试剂溴甲酚绿(Bromocresol green,BG)发生氧化反应后使其吸光度值降低,建立了一种可间接测定羟基自由基的新方法.确定了体系的最佳实验条件,采用抗坏血酸和硫脲为羟基自由基清除剂测定了其羟基自由基清除率D%及其与清除剂的线性回归方程.用拟定羟基自由基测定新方法应用于光催化降解孔雀绿(Malachite green,MG)体系中的羟自由基含量测定,表明该方法可作为测定羟基自由基和筛选抗氧化剂的方法之一.     

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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