硫酸氢钠催化合成乙酸异戊酯

以乙酸和异戊酸为原料，采用硫酸氢钠为催化剂合成了乙酸异戊酯，当反应时间为1h，醇酸物质的量比为1：3，催化剂用量为醇酸总量的3．0％，反应温度为130～135℃，酯的产率可达85％以上。     

食用香料肉桂酸异戊酯合成研究

以钨硅酸代替硫酸催化合成肉桂酸异戊酯．考察了醇酸摩尔比，带水剂及催化剂用量、反应时间等对合成的影响，得到合成肉桂酸异成酯的较适宜条件．     

活性碳负载12-钨磷酸催化合成乙酸异戊酯

以乙酸和异戊醇为原料，用活性碳负载12-钨磷酸作催化剂合成了乙酸异戊酯，探讨了醇酸摩尔比、催化剂用量、反应时间、带水剂用量对酯化产率的影响，考察了催化剂重复使用效果，确定了最佳实验条件．     

硅胶载体酸催化下乙酸异戊酯的合成

以乙酸和异戊醇为原料,采用硅胶载体酸为催化剂合成乙酸异戊酯.当醇酸物质量比为1∶2,催化剂用量为酸醇总量的5.5%,反应温度为130～135℃,反应时间为2 h左右时,乙酸异戊酯的产率可达到93.8%.     

固体超强酸TiO2/SO2-4催化合成乙酸戊酯的研究

对以固体超强酸TiO2／SO^2-4为催化剂，冰醋酸和戊醇为原料，催化合成乙酸戊酯的反应进行了研究，探讨了催化剂用量、醇酸比、反应时间等对酯化反应的影响。结果表明：醇酸摩尔比为1：3，催化剂用量为1．5g,反应时间为1．5h，酯的产率达94．6％。     

硫酸氢钠催化合成乙酸异戊酯

以乙酸和异戊酸为原料,采用硫酸氢钠为催化剂合成了乙酸异戊酯.当反应时间为1h,醇酸物质的量比为1∶3,催化剂用量为醇酸总量的3.0%,反应温度为130～135℃,酯的产率可达85%以上.     

乙酸戊酯合成条件的优化研究

以硫酸氢钠为催化剂,对以乙酸和正戊醇为原料合成乙酸戊酯的反应条件进行了研究,并分析了醇酸摩尔比、催化剂用量、反应时间、回流温度诸因素对收率的影响.实验结果表明,硫酸氢钠是合成乙酸戊酯的良好催化剂;最佳反应条件为:乙酸、正戊醇和硫酸氢钠的摩尔比为1∶1.25∶0.04,反应时间为45min,回流温度为112~140℃.满足上述条件酯收率可达96.4%.     

微波辐射下乙酸异戊酯合成条件研究

在微波辐射下，以SO4^2-／TiO2固体超强酸为催化剂合成乙酸异戊酯。最佳反应条件是：乙酸和异戊醇的摩尔比为1：2．0，催化剂用量为1．5g。微波输出功率为729W，反应时间为12min。在此反应条件下，乙酸的酯化率为94．7％，产品收率为89．7％。     

硫酸钛催化合成乙酸异戊酯

研究了硫酸钛催化下的乙酸异戊酯的合成．酯化率高达98％以上，酯化条件如下：异戊醇0．2mol，乙酸0．22mol，反应时间1h，硫酸钛的用量为反应物总质量的1．5％。     

硫酸氢钠催化合成异戊酸异戊酯的研究

利用硫酸氢钠作为酯化反应催化剂合成了异戊酸异戊酯，其最佳反应条件为：催化剂用量1.Og，醇酸摩尔比1．5：1．0，带水剂甲苯10ml，反应时间1．5h，酯化率可达90．3％。该催化剂易分离回收，可重复使用。     

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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