Reimer-Tiemann反应合成2-羟基-1-萘甲醛方法的改进

采用Reimer-Tiemann反应合成2-羟基-1-萘甲醛,用甲醇作溶剂,改变反应物NaOH的加入方式,能有效地提高反应产率,并且能简化产物的分离提纯步骤。     

Gel time of calcium acrylate grouting material

INTRODUCTION One of the main advantages of chemical groutsis easy control of gel time (Mollamahmutoglu andLittlejohn, 1996; ?nupárek and Soucek, 2000).Calcium acrylate is a chemical grout usually used ingeotechnical engineering (Zelanko and Karfakis,1997), and is a water-soluble monomer that po-lymerizes in an aqueous solution. The rate of po-lymerization is controlled by the concentration ofcatalyst and activator. The polymerization of cal-cium acrylate is free radical chain pol…     

Timing issues in distributed testing

The objective of conformance testing is to determine whether an implementation under test (IUT) conforms to its specification. In distributed test architecture where there are multiple remote testers, the objective can be complicated by the fact that testers may encounter controllability and observability problems during the application of a test sequence. A certain amount of work has been done in the area of generating test sequence that is free from these problems. However, few researchers investigate them from the aspect of test execution. This work studies the test execution phase when test sequences are applied to the imple- mentation and it is pointed out that controllability and observability problems can be resolved if and only if the test system im- plements some timing constraints. When determining these constraints, the dynamic time information during test is taken into account, which reduces the test execution time and improves test efficiency further.     

社会比较嫉妒与爱情嫉妒关系探讨

社会比较嫉妒与爱情嫉妒的关系问题是学者对嫉妒情绪进行研究时首先要探讨的一个问题。前者主要在社会比较情境下产生,后者则产生于恋爱关系。由于文化差异,东方学者的研究聚焦于社会比较嫉妒,倾向于将爱情嫉妒看做社会比较嫉妒的一个特例。而西方学者主要对关系嫉妒(尤其是爱情嫉妒)进行研究,倾向于将社会比较嫉妒看成爱情嫉妒的一部分。本文在国内外学者研究基础上,从情绪体验、行为反应模式、嫉妒者认知、生理机制等方面对二者区别进行分析,并基于恋爱关系、社会比较两大背景,对二者联系进行了探讨。最后,本文认为二者产生的根源相同,从产生根源角度对二者之间关系进行了深入分析。     

热化学反应动力学研究

NH4Cl和NaNO2在一定条件下反应产生大量的热和气体,利于蜡的熔化和剥离,只有掌握它的反应动力学特征,了解它的最佳反应条件及其影响因素,才能更好的利用其热量。本文通过测量不同条件下两者反应生成气体和温度的变化量,计算出各种相关的动力学参数,得到该反应的动力学方程。     

对肼基苯磺酸的合成方法的优化

对肼基苯磺酸是一类应用十分广泛的中间体，在多个领域有着重要用途，本文设计分别利用盐酸和硫酸不同条件下对肼基苯磺酸进行合成，讨论不同条件下对产率的影响，最终发现，利用盐酸法比硫酸法提高产率较大。     

MATLAB在化学反应工程中的应用

以化学反应工程中常见的反应器稳定性分析为例,介绍MATLAB在化学反应工程中的应用。教学实践证明,MATLAB简洁易懂的编程语言、方便灵活的图形绘制及强大的计算能力,在求解化学反应工程中复杂的数学模型时,显示出无可比拟的优势,学生的工程计算能力也得以提升。     

Gel time of calcium acrylate grouting material

Calcium acrylate is a polymerized grout, and can polymerize in an aqueous solution. The polymerizationreaction utilizes ammonium persulfate as a catalyst and sodium thiosulfate as the activator. Based on the theory of reactionkinetics, this study on the relation between gel time and concentration of activator and catalyst showed that gel time ofcalcium acrylate is inversely proportional to activator and catalyst concentration. A formula of gel time is proposed, and anexample is provided to verify the proposed formula.     

医药保健品褪黑素工业合成路线的探究

褪黑素是松果体腺分泌的话性最高的内源性激素,它在催眠、抗癌、抗衰老等方面起着重要作用。以邻苯二甲酸酐、1,3-二溴丙烷、对甲氧基苯胺为原料,经过取代、缩合、成环、乙酰化等步骤来完成褪黑素（又名脑白金）的合成,探究了其适合的工业合成条件。     

A quantum chemistry study on reaction mechanisms of SO2 with O3 and H2O2

Reaction mechanisms of SO2 with O3 and H2O2 were investigated using quantum chemistry ab initio methods. Structures of all reactants, products, and transition states were optimized at the B3LYP/6-311G＋（3df,2p） level, and energy calculations were made at the G2M level. SO2 reactions with O3 and H2O2 occurred by O-abstraction and OH-abstraction by SO2, respectively, at length forming SO3＋O2 （3Eg） and H2SO4. For SO2＋O3 reactions the barrier height was predicted to be 9.68 kcal/mol with a rate constant of 3.61 × 10^-23 cm^3/（molecule.s） at 300 K, which is below the experimental upper limit. The rate constant predicted for this reaction accords well with the one provided by National Institute for Standards and Technology （NIST） in 250-500 K. For SO2＋H2O2 reactions the barrier height was predicted to be 62.39 kcal/mol with a rate constant of 2.48× 10^-61 cm^3/（molecule.s） at 300 K.