正交实验法确定乙酸环己酯合成最佳条件的研究

采用5因素4水平L16(45)进行正交实验,探索了乙酸与环己醇酯化制备乙酸环己酯的反应中催化剂、反应时间、反应温度、带水剂的用量、反应物物质的量之比等因素对乙酸环己酯产率的影响.结果表明:各因素对乙酸环己酯产率影响的主次顺序为:催化剂>反应温度>带水剂的用量>反应原料比>反应时间.确定了合成工艺条件为:适宜原料比为n环己醇:n乙酸=1.5:1,适宜催化剂为催化剂I,适宜反应温度为75℃,适宜反应时间为1.5 h,带水剂的最佳用量为6 mL,该条件下乙酸环己酯的产率在97.5%左右.与现行生产工艺相比,该合成路线催化剂的催化性能强、反应时间短、用量少、能重复使用,并且工艺简单、无污染、产物产率较高等优点.     

Hβ分子筛一步催化合成乙酸松油酯的研究

以固体酸-Hβ分子筛为催化剂,较系统地研究了由松节油与乙酸一步合成乙酸松油酯的工艺条件.考察了浸渍条件、分子筛的硅铝比、反应温度、反应时间和反应物的配比对反应的影响.结果表明,在反应温度20℃、乙酸和蒎烯配比100∶15、反应时间24 h,以硅铝比60的Hβ分子筛为催化剂,蒎烯的转化率可以达到75.5%,乙酸松油酯的得率为22.8%.     

乙酸和丙烯一步合成乙酸异丙酯工艺

在Ti材高压釜中进行了催化剂的筛选和工艺条件的优化.考察催化剂种类及用量、反应温度、压力、时间等因素对反应的影响.通过催化剂的筛选,发现自制固体催化剂的活性高于采用对甲苯磺酸、β型分子筛作为催化剂的活性.采用自制固体催化剂,适宜的反应工艺条件为:反应温度130℃,催化剂用量为乙酸质量的7.5%,压力1.5MPa,反应时间6 h.在此条件下,乙酸转化率可达到85.43%,乙酸异丙酯对丙烯的选择性为98.52%.     

固体超强酸SO_4~(2-)/ZrO_2催化α-蒎烯异构反应

<正>研究了固体超强酸SO2-4/ZrO2催化剂的制备条件(硫酸浸渍浓度、焙烧温度等)对其催化性能的影响。结果表明,催化剂的制备条件不同,对莰烯选择性和α 蒎烯转化率有较大影响。适宜的催化剂制备条件是:硫酸浓度0.5～1.0mol/L,焙烧温度650℃。对所制备的SO2-4/ZrO2固体超强酸作为α 蒎烯异构反应的催化剂,以及对影响反应过程的主要因素进行探讨。优化的工艺条件为:反应时间1～3h,反应温度(130±2)℃,催化剂质量分数3%～4%。该条件下α 蒎烯转化率96.4%,莰烯选择性49.7%。此外,还分析了催化剂放置时间对异构产物的影响及催化剂重复使用情况。     

固体超强酸SO2-4/ZrO2催化α-蒎烯异构反应

研究了固体超强酸SO2-4/ZrO2催化剂的制备条件(硫酸浸渍浓度、焙烧温度等)对其催化性能的影响.结果表明,催化剂的制备条件不同,对莰烯选择性和α-蒎烯转化率有较大影响.适宜的催化剂制备条件是: 硫酸浓度0.5～1.0 mol/L,焙烧温度650 ℃.对所制备的SO2-4/ZrO2固体超强酸作为α-蒎烯异构反应的催化剂,以及对影响反应过程的主要因素进行探讨.优化的工艺条件为:反应时间1～3 h,反应温度(130±2)℃,催化剂质量分数3%～4%.该条件下α-蒎烯转化率96.4%,莰烯选择性49.7%.此外,还分析了催化剂放置时间对异构产物的影响及催化剂重复使用情况.     

甲基丙烯酸异冰片酯的合成及性能研究

以莰烯和甲基丙烯酸为原料,采用直接加成酯化法合成甲基丙烯酸异冰片酯(IBOMA).分析了反应时间、反应温度、莰烯与甲基丙烯酸的物质的量之比、催化剂种类及用量、阻聚剂种类及用量等对产物得率和反应选择性的影响,并采用正交试验对反应条件进行了优化,确定了适宜的合成工艺条件:以10％的Amberlyst 15作催化剂、0.03％的吩噻嗪作阻聚剂、甲基丙烯酸与莰烯物质的量之比为1.3∶1、酯化温度为60℃、反应时间为8～9 h,在此工艺条件下,产物甲基丙烯酸异冰片酯的平均得率为80.2％,平均选择性为95.3％,酯含量大于99.2％.采用GC-MS、FT-IR等分析技术对产物性能进行了表征.     

固体超强酸SO4^2-／ZrO2催化α-蒎烯异构反应

研究了固体超强酸SO2-4/ZrO2催化剂的制备条件(硫酸浸渍浓度、焙烧温度等)对其催化性能的影响.结果表明,催化剂的制备条件不同,对莰烯选择性和α-蒎烯转化率有较大影响.适宜的催化剂制备条件是 硫酸浓度0.5～1.0 mol/L,焙烧温度650 ℃.对所制备的SO2-4/ZrO2固体超强酸作为α-蒎烯异构反应的催化剂,以及对影响反应过程的主要因素进行探讨.优化的工艺条件为反应时间1～3 h,反应温度(130±2)℃,催化剂质量分数3%～4%.该条件下α-蒎烯转化率96.4%,莰烯选择性49.7%.此外,还分析了催化剂放置时间对异构产物的影响及催化剂重复使用情况.     

烯丙基异冰片基醚绿色合成研究

以莰烯和烯丙醇为原料,研究了烯丙基异冰片基醚的绿色合成工艺,探讨了催化剂种类及用量、反应温度、反应时间,以及烯丙醇与莰烯物质的量之比对莰烯醚化反应选择性及烯丙基异冰片基醚产物得率的影响。采用正交试验方法确定了烯丙基异冰片基醚的最适工艺条件:A-15型阳离子树脂为催化剂,催化剂用量为烯丙醇和莰烯原料总质量的5%,烯丙醇与莰烯物质的量之比为1.5∶1,反应温度75℃,反应时间7 h。在此条件下工业莰烯转化率为85.5%,反应选择性为97.5%,烯丙基异冰片基醚得率为83.4%。最后采用GC-MS、IR等分析技术对合成所得产物的结构进行了分析测定。     

复合固体超强酸S2O82-/Fe2O3/ZnO/ZrO2催化合成乙酸异戊酯

采用沉淀、老化、浸渍、干燥、焙烧等方法制备复合固体超强酸催化剂S2O28-/Fe2O3/ZnO/ZrO2,在该固体超强酸的催化作用下,由异戊醇和冰乙酸合成乙酸异戊酯,探讨醇酸摩尔配比、反应温度、反应时间、不同焙烧温度以及催化剂用量等条件对酯化率的影响。结果表明,此催化剂制备的最优条件为:焙烧温度为650℃,(NH4)2S2O8浸渍浓度为0.5 mol/L,焙烧时间为3 h。合成乙酸异戊酯适宜的反应条件是:反应时间50 min,原料异戊醇与冰乙酸的摩尔配比为2:1,用量为1 g,用复合固体超强酸S2O28-/Fe2O3/ZnO/ZrO2催化剂催化合成乙酸异戊酯的产率是88.5%。     

乙酸苯酯合成新方法研究

采用自制的催化剂，运用条件实验法，以苯酚、乙酐为原料，直接酯化合成乙酸苯酯，分别研究了反应温度、反应时间、原料配比、催化剂用量、精馏温度等条件对合成反应的影响，确定了最佳工艺条件。该方法合成乙酸苯酸的最佳工艺条件是反应温度135－145℃，反应时间90min，苯酚与乙酐物质的量比为1．00：1．05，催化剂用量为占体系总量的0．03％，精馏温度194－196℃，在此条件下，乙酸苯酯的收率达到98．7％。     

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.     

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