丙二酸二乙酯相转移烷基化反应的协同作用

研究了使用Ｗｏｎｇ盐、聚乙二醇为相转移催化剂、丙二酸二乙酯与烷基化试剂在碳酸钾存在下的固－液相转移烷基化反应。研究表明，在一定反应时间内对于Ｗｏｎｇ盐催化剂加入量超一定量后，产物收率不再提高；若在此界量后，协同使用Ｗｏｎｇ盐与聚乙二醇，则产率仍可提高，从而表现出协同作用。     

一种合成2，5—二甲氧基苯甲醛的新方法

2，5－二甲氧基苯甲醛是重要、不易合成的药物中间体。以对甲氧基苯酚为原料，经聚乙二醇10000催化的Reiman-Tiemann反应及甲氧基化制备而得。通过比较不同相转移催化剂对Reimer-Tiemann反应产率的影响，选择效果最佳的聚乙二醇－10000（PEG－10000）作为该反应的相转移催化剂。把2－羟基－5－甲氧基苯甲醛的甲氧基化放在缓冲溶液中进行，产物的收率和品质有明显提高。就影响产率的各种因素进行了探讨，并从机理上作了简要解释。通过反应条件改进，总收率达68％。     

苹果酯—B的合成

以Ｆｅ＾３＋－ＵＲ为催化剂，催化乙酰乙酸乙酯和１，２－丙二醇缩合反应合成了新型香料果酯－Ｂ。在最佳反应条件下，产物收率为８５．１％。     

2—（三氯甲基）—2—丙醇的相转移催化法合成研究

用聚乙二醇－４００作为相转移催化剂合成２－（三氯甲基）－２－丙醇，反应在碱性介质中进行，条件温和，反应温度控制在５～１０℃原料的摩尔配比为丙酮：氯仿：氢氧化钠：聚乙二醇－４００＝１０：１０：７：１．产率为３０．４％。     

2-甲基吡啶的合成工艺研究

为了更加简洁高效制取重要的精细化工原料—2－甲基吡啶,以乙炔与乙腈为原料反应合成2－甲基吡啶,通过正交实验,结果表明,在适宜反应条件,即反应温度为180℃,催化剂用量为200 mg,反应时间为12 h,目标物收率可达53.43%.反应生成的混合物水溶液通过过滤、间歇精馏制得含量≥98％的2－甲基吡啶产品,该工艺路线步骤简单、收率高、且易于操作.     

聚乙二醇在蓖麻油皂化反应中的相转移催化作用

本文以聚乙二醇（ＰＥＧ）为相转移催化剂对蓖麻油的皂化反应进行了研究．实验结果表明：聚乙二醇在蓖麻油皂化反应中有明显的催化作用，可使反应温度降低，反应时间大大缩短，通过对不同分子量ＰＥＧ催化效果的研究，发现其中以ＰＥＧ－４００的催化效果为最好。此外，本文还讨论了反应温度、碱用量以及催化剂用量对反应的影响。     

相转移催化法合成醋酸丁酯

利用相转移催化法，以正丁醇和乙醇酐为原料，成功地合成了醛酸丁酯，其特点是反应仅需１０ｍｉｎ，收率８５％－９０％，酯含量９８％－９９％。     

固体超强酸TiO2／SO^2—4催化合成苯氧乙酸烯丙酯

用ＴｉＯ２／ＳＯ＾２－４固体超强酸催化苯氧乙酸与烯丙醇的酯化反应，研究了反析了反应因素对酯化反应产率的影响；最佳反应条件下，产物收率可达８６．０％。     

TiO2／SO4^2—固体超强酸催化合成丁二酸二丁酯的研究

使用自制的固体超强酸ＴｉＯ２／ＳＯ４＾２－催化合成丁二酸二丁酯，考察了催化剂活化温度等因素对丁二酸二丁酯收率的影响，在最佳反应条件下，丁二酸二丁酯收率为９１．７％。     

α-苄基苯乙腈的三相相转移催化合成

利用固载化聚乙二醇－400作三相相转移催化剂，以氢氧化钾的水溶液作碱，从苯乙腈和苄基氯出发合成了苯乙腈的单烷基化物－α－苄基苯乙腈。该合成方法具有收率高、反应条件温和等优点，另外，在催化反应结束后，所用固载催化剂易于回收，且重复使用性能良好。     

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.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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