高选择性制备呋喃铵盐工艺的改进

目的:通过工艺改进实现原料2-乙酰呋喃的完全转化,提高中间体2-甲氧亚氨基-2-呋喃乙酸的顺式结构的选择性,从而提高呋喃铵盐的收率,降低成本.方法:以2-乙酰呋喃为原料,通过氧化、肟化、成盐三步反应制备呋喃铵盐.结果:通过液相检测2-乙酰呋喃的氧化转化率提高到100%,2-甲氧亚氨基-2-呋喃乙酸的顺式选择性从82.55%提高到97%,产品收率达到85%.结论:该制备方法操作简便、工艺稳定、收率高.     

Pd/C催化水合肼还原法制备对氨基苯乙酸

研究了在Pd/C催化下水合肼还原对硝基苯乙酸制备对氨基苯乙酸的方法.讨论了反应时间、反应温度、水合肼及催化剂用量对产物收率的影响,在优化条件下对氨基苯乙酸的收率达89.52%.经IR、MS和NMR证实了其结构.     

邻卤苯乙酸合成方法的改进

以NaOH溶液快速沉淀CuCl2和AlCl3的混合溶液制备了催化剂CuO-Al2O3.在20%NaOH水溶液中,以CuO-Al2O3催化水合肼还原邻硝基苯乙酸得到邻氨基苯乙酸,经重氮化和卤置换反应得到邻卤苯乙酸,收率65%~73%.总收率为40%~45%.     

相转移催化合成乙酸苄酯香料

用氯化苄和乙酸钠为原料，以相转移催化法合成乙酸苄酯香料。提出了最佳工艺条件和反应过程中催化剂、过剩反应物料循环利用的可行性。结果表明，转化率高达９９％，选择性为９８％～１００％；产品收率在９０％～９５％．工艺过程简单，副反应很少，是乙酸苄酯生产的一条高产、优质、低成本的有效途径。     

三乙基苄基氯化铵催化合成乙酸苄酯工艺研究

文章利用相转移催化剂三乙基苄基氯化铵（TEBAC）催化合成乙酸苄酯,最佳反应条件如下：氯化苄∶乙酸钠=1∶1.4,催化剂用量为9%,反应温度为98℃～102℃,反应时间为3 h,酯收率达88.8%.实验证明,三乙基苄基氯化铵催化合成对该酯化反应是高效、低成本和实用的方法.     

四元复合涂层钛阳极的制备及其在红矾钠合成中的应用

采用热分解法制备含中间涂层IrO_2的Ir-Ta-Ti-Nb/Ti四元复合涂层钛阳极,对比考察了该四元复合涂层钛阳极及传统涂层钛阳极在电催化合成红矾钠过程中的槽电压、电流效率等工艺参数,并采用XRD和SEM方法分析四元复合涂层电催化前后组织结构特征和表面形貌。结果表明,该四元复合涂层钛阳极在电催化合成红矾钠的过程中槽电压约为3. 2 V、平均电流效率为94. 50%、平均转化率为95. 01%,相比于传统涂层钛阳极的工艺参数(槽电压约为3. 4 V、平均电流效率为92. 10%、平均转化率为92. 80%),其工艺参数更优异,且涂层电催化前后的主要物相和表面形貌未发生变化,说明制备的涂层钛阳极具有较好的稳定性和电催化性能。     

软锰矿浸出液有机物对锰电解电流效率的影响

通过电解小试实验,研究甲酸、乙酸、柠檬酸、酒石酸、乌头酸、葡萄糖及蔗糖等有机物对锰电解电流效率(MECE)的影响.结果表明:甲酸、乙酸和柠檬酸等有机酸在一定质量分数范围内均可提高锰电解电流效率,达73%左右,最高可达77.9%,但有机酸质量分数过高,锰电解电流效率反而降低;葡萄糖和蔗糖粘度较高、质量分数过大,会阻碍电解液中离子的迁移,从而导致锰电解电流效率下降.     

用AC法从高锑低银类铅阳极泥中回收银和铅

用AC法处理高锑低银类铅阳极泥,其氯化浸出渣经转化脱氯、硅氟酸浸铅、氨水浸银和水合肼还原,得到含Ag大于95%的银粉,铅以硅氟酸铅溶液返回电解精炼.在V苏打溶液/m浸出渣=4mL/g,n苏打实=1.6n苏打理,转化时间为4h及温度为80℃的最佳转化条件下,铅、银、氯的平均转化率为91.42%;在V(H2SiF6)/m浸出渣=4mL/g,浸出时间为1h,温度为50～60℃的最佳浸铅条件下,硅氟酸浸铅率为85.74%～86.07%,硝酸浸铅率大于95%;在浸银过程中,银的浸出率约为94.0%,沉银率约为98.0%.在整个工艺中,银的直收率及总回收率分别为93.63%及98.80%,铅直收率为85.91%,总回收率98.99%.     

无水三氯化铝催化合成N,N-二甲氧基羰基乙基苯胺的研究

报道了用无水三氯化铝作催化剂在低温下将苯胺和丙烯酸甲酯转化为N ,N -二甲氧基羰基乙基苯胺的新方法 ,其反应转化率达 95 %以上 ,产品收率高于 91% ,纯度高于96 % .     

乙酸异戊酯的合成研究

研究了乙酸异戊酯的合成条件及工艺过程。用固体酸对氨基苯磺酸作催化剂,以异戊醇和冰乙酸直接酯化合成乙酸异戊酯。产物后处理简单,收率80%,催化剂可重复多次使用。     

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.     

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     

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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Brief Introduction to “Journal of Jilin University( Science Edition) ”

<正>"Journal of Jilin University(Science Edition)"is a comprehensive academic journal in the fields of science sponsored by Jilin University and administrated by the Ministry of Education of the Peoples Republic of China.The journal started publication in 1955.The original name at starting publication was"Journal of Natural Science of Northeast People University",which was changed into"Acta Scientiarum Naturalium Universitatis Jilinensis"in 1958 owing to the name change of the university.The present journal name has