重型柴油机固态铵选择性催化还原系统铵盐热解及动力学特征研究

通过开展选择性催化还原(SCR)系统中铵盐的热解及动力学特征研究,为固态铵SCR氨气生成及氨气供给系统的设计提供理论依据及技术支撑,采用热重实验和分解平衡压实验分析了3种铵盐的分解温度、分解速率等热解特性,利用等温法和积分法计算了氨基甲酸铵和碳酸铵的分解动力学参数。碳酸铵和氨基甲酸铵的受热分解就是在恒定温度下测定其剩余质量比与受热时间的关系,再在热重分析曲线中通过反应时间下的剩余质量比求得速率常数和反应级数。研究结果表明:氨基甲酸铵分解速率大于碳酸铵和碳酸氢铵;氨基甲酸铵分解反应级数为1/2,碳酸铵的为2/3,氨基甲酸铵活化能为56kJ/mol,碳酸铵的为62kJ/mol;氨基甲酸铵和碳酸铵均适合作为固态铵选择性催化还原(SSCR)系统还原剂的来源,氨基甲酸铵优势更明显。相比尿素SCR技术,固态铵SCR技术在发动机低排气温度条件下能够提供足量的还原剂,有效提高低温NOx转化效率。     

干法合成氨基甲酸铵的研究

氨基甲酸铵分解反应是一个典型的复相反应.固体氨基甲酸铵很不稳定,受热极易分解.若不将CO_2 和 NH_3 气体从反应体系中移走,反应很容易达成平衡,因此,基础物化实验中测定复相反应的平衡常数时常常选用这个反应作为研究的对象,由于氨基甲酸铵固体很不稳定,加上它遇水后立即生成碳酸铵和碳酸氢铵,因此很不容易保存.实验室所用的氨基甲酸铵固体常需临时制备,才能保证纯度.     

年产132kt甲胺反应器工艺和结构尺寸的确定

介绍了氨基甲酸铵的用途及其生产方法,对年产13.2万吨甲胺气液反应器的各部件进行了工艺尺寸和结构尺寸的确定。     

“氨基甲酸铵分解压力测定“实验中真空度该达多少

根据基础热力学数据,对氨基甲酸铵分解反应的平衡常数和分解压力进行了计算,得出了该实验所需要真空度的准确理论数据.     

氯代邻羟基二苯醚类化合物的合成工艺

氯代邻羟基二苯醚类化合物被广泛用作杀茵剂、医药及日化、卫生用品等的抗茵成分.目前,该类化合物主要通过氯代邻氨基二苯醚重氮化水解反应制得,由于制备过程伴有分子内关环副反应,导致产品收率和质量很低.文中对影响氯代邻氨基二苯醚重氮化水解反应的主要因素和工艺条件进行了系统研究,结果表明,取代基对氯代邻氨基二苯醚重氮盐的水解和分子内关环反应的选择性有重要影响,金属离子对分子内关环反应有显著催化作用,制备氯代邻羟基二苯醚的较佳工艺条件为:重氮化硫酸质量分数为95%～98%;水解硫酸质量分数为74%～78%;重氮化温度为55～60℃;水解温度为160～175℃.     

叔丁基-2-氨基-4-苯乙基苯基氨基甲酸酯合成方法比较

采用氢气/钯碳常压合成法、氢气/钯碳加压合成法、甲酸铵/钯黑合成法、甲酸铵/钯碳合成法4种催化氢化合成方法,首次分别合成了新化合物叔丁基-2-氨基-4-苯乙基苯基氨基甲酸酯,并对产物进行了结构表征.通过对所采用的4种合成方法的系统研究,其中甲酸铵/钯碳合成法具有反应时间短、反应条件温和、收率高的特点.     

阿克他利的合成

以苯乙腈为原料,经硝化、水解、还原以及酰化等4步反应对阿克他利(Actarit,对乙酰氨基苯乙酸)及其中间体的合成条件进行了研究和改进.目的产物用元素分析、红外光谱及核磁共振氢谱进行了表征.研究发现对硝基苯乙腈合成的最适温度为7～8℃.在回流温度152℃,对硝基苯乙腈水解且搅拌充分的情况下效果最为理想,对硝基苯乙酸的还原以水溶液中醋酸活化的铁粉为还原剂效果较好.乙酸酐与对氨基苯乙酸的比例为1.5:1(物质的量比)时对乙酰氨基苯乙酸的合成较好,4步反应总收率可达50.5%.     

双（2─羟乙基）氨基二硫代甲酸铵的合成及若干螯合物光谱特性的研究

合成了广谱性螯合剂，双（２—羟乙基）氨基二硫代甲酸铵，研究了试剂及金属离子整合物的广谱特性．     

一种新的氨基甲酸铵分解平衡实验装置

文中给出了一种新的氨基甲酸铵分解平衡实验装置 ,并对新旧实验装置进行了对比分析。通过对新装置的测试及学生实验效果的检验 ,证明新的实验装置除保留了原装置的优点外 ,又弥补了原装置的许多不足     

邻苄基氨基苯酚的合成研究

以邻氨基苯甲醚和苄基氯为原料,以3-甲基吡啶作为缚酸剂,进行缩合反应制得邻苄基氨基苯甲醚,然后在路易斯酸催化下脱去甲基,酸性条件下水解,得目标化合物邻苄基氨基苯酚.并对合成邻苄基氨基苯甲醚的工艺条件以及脱甲基条件进行了初步探讨.     

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

正~~