催化合成马来酸二辛酯的固体超强酸 SO42-/TiO2的制备

制备了固体超强酸SO42/TiO2替代用于合成马来酸二辛酯的硫酸、对甲苯磺酸催化剂,并与硫酸对甲苯磺酸的催化结果进行了比较.考察了硫酸浓度、浸渍时间、焙烧温度、焙烧时间对催化剂活性和反应时间对酯化反应的影响.结果表明,对于给定反应,当浸渍液硫酸浓度为0.5mol/L、浸渍时间为18h、在550℃下焙烧2h时具有最高的催化活性,用于马来酸酐和正辛醇的酯化反应可得无色透明的酯化产物,3h内酯化率达97.8%.     

用于催化合成马来酸二辛酯的固体超强酸SO4^2—／ZrO2的制备

制备了固体超强酸SO4^2-/ZrO2，用其代硫酸，对甲苯磺酸催化剂用于合成马来酸二辛酯，并与硫酸、对甲苯磺酸的催化结果作了比较。结果表明：当浸渍液硫酸浓度为1mol/L、浸渍10h、在550℃下焙烧2h时，具有最高的催化活性和使用重复性，用于马来酸酐和正辛醇的酯化反应可得无色透明的酯化产物，3h内脂化率达97.4%。     

催化合成马来酸二辛酯的固体超强酸SO4^2—／TiO2的制备

制备了固体超强SO4^2-/TiO2替代用于合成马来酸二辛酯的硫酸、对甲苯磺酸催化剂，并与硫酸对甲苯磺酸的催化结果进行了比较。考察了硫酸浓度、浸渍时间、焙烧温度、焙烧时间对催化剂活性和反应时间对酯化反应的影响。结果表明，对于给定反应，当浸清液硫酸浓度为0．5mol/L、浸溃时间为18h、在550℃下焙烧2h时具有最高的催化活性，用于马来酸酐和正辛醇的酯化反应可得无色透明的酯化产物，3h内酯化率达97．8％。     

SO42-促进铈改性SBA-15分子筛催化合成乙酸正丁酯

采用一步法制备了铈改性SBA-15分子筛(Ce-SBA-15),进一步用硫酸浸渍处理改性分子筛以增强分子筛表面的酸活性中心.以改性材料为催化剂催化合成乙酸正丁酯,考察了催化剂的制备条件.实验结果表明,将铈改性SBA-15分子筛以1 mol/L硫酸浸渍后,在500℃条件下焙烧3 h,用于合成乙酸正丁酯,反应2h后,酯化率可达到97.28%.     

柠檬酸三丁酯的合成研究

介绍了对甲苯磺酸和硫酸氢钾混合催化剂合成柠檬酸三丁酯的研究。考察了催化剂配比、催化剂用量、原料配比、反应温度和反应时间等因素对合成反应的影响,确定了最佳反应条件:酸醇摩尔比为1:4.5,催化剂用量为3.0%,对甲苯磺酸和硫酸氢钾质量比为1:3,反应温度为140～150℃,反应时间为3h,柠檬酸三丁酯酯化率可达到96.9%。     

对甲苯磺酸催化合成异丁酸乙酯的研究

对甲苯磺酸作为异丁酸和乙醇的酯化催化剂,性能优于硫酸,本文探讨并确定了异丁酸与乙醇酯化反应的最佳条件。     

对甲苯磺酸催化合成丁酸异戊酯

对甲苯磺酸作为丁酸和异戊醇的酯化催化剂,性能优于硫酸。探讨并找到了其较好的反应条件,酯化率可达９７．６％。     

SO2-4/ZrO2-SiO2 超强酸催化剂研究(Ⅰ)—制备及对乙酸/丁醇酯化反应的催化活性

采用0.3～2.0 mol/dm3 的硫酸水溶液浸渍预焙烧过的二元氧化物, 然后在450～650 ℃ 的温度下焙烧3～5 h, 制得SiO2/ZrO2 摩尔比为1∶9～30的SO42-/ZrO2-SiO2催化剂.ZrO2-SiO2 二元氧化物前体由沉淀/混合沉淀法制得.对于乙酸/丁醇酯化反应,所制得的催化剂的活性比传统的SO2-4/ZrO2催化剂高6～10倍.考察了SiO2/ZrO2摩尔比,硫酸水溶液浓度,预焙烧温度和焙烧温度等制备条件对催化剂活性的影响.SiO2/ZrO2摩尔比为10～15,以1.0 mol/dm3 硫酸溶液浸渍,且在550℃温度下焙烧制得的催化剂表现出最好的催化活性.     

对甲苯磺酸催化合成肉桂酸异戊酯

肉桂酸异戊酯是一种重要的高级香料,具有可可香味,广泛用于食品和日用化工等领域.合成肉桂酸异戊酯的传统方法是以硫酸为催化剂直接酯化生产肉桂酸异戊酯,硫酸同时具有酯化、脱水和氧化作用,产生一系列副反应,后处理繁杂,产品质量差,收率低,污染环境,同时硫酸对设备具有严重腐蚀,使产品成本升高.因此,国内外都在探索代替浓硫酸的新型催化剂.笔者将对甲苯磺酸用于催化合成肉桂酸异戊酯,取得较满意结果.     

MCM-41负载对甲苯磺酸催化合成柠檬酸异辛酯

采用浸渍法将对甲苯磺酸(p-TSA)负载到碱性条件下水热法制备的介孔分子筛MCM-41(p-TSA/MCM-41)上,通过FT-IR,XRD,BET,TG,TEM和EA测试技术对其进行了表征.以柠檬酸异辛酯的合成为探针实验,研究了p-TSA/MCM-41的催化性能.结果表明,该酯化反应的最佳条件为:160℃时,p-TSA/MCM-41用量为柠檬酸质量的3%,柠檬酸与异辛醇摩尔比为1∶5,反应2.5h柠檬酸异辛酯的酯化率达96.7%.     

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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