关于物理化学实验教学改革的几点思考

探讨物理化学实验的目的、内容、要求及成绩评定方法,提出用演示实验改造物理化学实验。     

思维能力导向的线上物理化学实验课程建设与应用

为了解决物理化学实验课程学习难度大与课堂教学时间少的矛盾,弥补传统的物理化学实验教学“重过程、轻结果”的缺点,建设了线上物理化学实验课程。线上物理化学实验课程通过实验原理和仪器操作视频、实验习题、问题讨论等模块,完成知识、技能和思维能力的培养,与线下实验操作训练形成良好的互补关系。线上物理化学实验课程为翻转传统的物理化学实验课堂提供了前提条件,明显提高了教学效果。     

翻转课堂在物理化学基础实验教学中的应用

结合物理化学基础实验自身特点,尝试将翻转课堂教学模式引入物化实验教学,详细分析了微课制作、课堂组织和教学评价等诸多环节。该教学模式可以有效地调动学生的学习主动性,使学生成为教学主体,有效地发挥基础实验在物理化学教学中的积极作用。     

化学演示实验的一些经验

演示实验,在化学课的课堂教学上,占着很重要的位置。如果演示能正确地完成,可以使学生获得正确而深刻的印象,容易掌握而牢记着科学知识。现在各中学所采用的高级中学化学课本,其中有许多演示实验,在演示时需特别注意的。这次我们在我校师资训练部的教学工作中,课前准备时,对这些实验,曾经集中力量,一一加以研究和试验,大部分已得到掌握实验的技术,能保证在课堂教学时,有把握地演示出满意的结果。现在把几个比较普通而重要的写出来,备教学时的参考。     

农林院校物理化学课程体系的优化及教学实践

为解决教学中课程内容与学生专业特点不相适应的问题,对物理化学理论、实验课程体系和教学内容进行了整合优化,形成了农林院校物理化学课程教学新体系。在现有的＂课堂教学＋学生讨论＋实践环节＂三段式教学方法的基础上,尝试＂问题教学＋参与式教学＂方法。     

微型电解实验探究案例

尽管实验探究被应用于中学化学教学中,但考虑到课堂时间和教学组织等一系列现实问题,一些老师还是会选择通过演示实验来完成相应的教学任务。比如在“电解”教学中,经常是教师先进行演示实验,然后师生共同总结电解的规律,课堂教学表面看起来“效率”很高,但学生从演示实验中获得的信息并不完整,一些实验现象根本就看不清楚,     

慎重做好演示实验

丰富多彩的课堂演示实验,对理解知识、探究原理、凝聚学生注意力从而提高课堂教学效果的作用无疑是非常明显的.那么怎样才能做好演示实验?现结合教学案例,谈些看法.     

演示实验与学生思维能力的培养

演示实验是教师课堂教学的重要手段。我认为演示实验不但要“精演”,而且要启迪学生“多思”,要与培养学生的创造性思维有机地结合起来。     

基于PBL的物理化学实验混合教学模式的设计与实践

依托自建物理化学实验在线开放课程及网络教学资源,在物理化学实验课程中开展了线上线下混合式教学."以问题为导向,以学生为中心"设计课程教学,开展探究式学习和过程性评价.通过课前线上预习、线下课堂教学和课后答疑指导等环节,实现了学生能力的进阶式培养,提高学生的自主学习能力、综合能力和创新能力.为高等学校实验类课程线上线下混合式教学模式的探索提供了范式.     

分光光度法测量碘的蒸气压计算晶体碘的标准熵和升华热

一、前言目前,国内外已把统计热力学基础作为物理化学教材中的一个组成部份.但在物理化学实验中却没有相应的实验与之配合。因此,课堂教学效果受到影响。鉴于此,陆续有人设计这方面的实验。本文用分光光度法,测量一定温度下晶体碘与其蒸气平衡时的蒸气压,然后用作图法求出晶体碘的特性温度θ,再通过     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

关于"对‘燃料电池物理及化学性能的有限时间热力学分析方法'的讨论”答复

把有限时间热力学理论用于化学过程的研究,将会得到一系列新的结论,开展这方面的研究是很有意义的.文献[1]以燃料电池为例,在同时考虑化学反应及传热不可逆性的情况下,研究了燃料电池的性能界限,文献[2]指出了文献[1]计算化学反应及传热不可逆性而引起系统与有关环境的总熵产生率的错误以及由此而导致的结论所存在的问题,并进行了富有启发性的分析与讨论.但文献[2]对于系统与有关环境的总熵产生率的计算也是不正确的,由此得到的其它结论自然不能成立.本文将就此情况下系统与有关环境的总熵产生率的计算再次进行讨论,并给出电池功率和效率的有限时间热力学性能界限.     

Regiospecific synthesis of quercetin O-β-d-glucosylated and O-β-d-glucuronidated isomers

Quercetin, the polyphenolic compound, which has the highest daily intake, is well known for its protective effects against aging diseases and has received a lot of attention for this reason. Both quercetin 3-O-β-d-glucuronide and quercetin 3′-O-β-d-glucuronide are human metabolites, which, together with their regioisomers, are required for biological as well as physical chemistry studies. We present here a novel synthetic route based on the sequential and selective protections of the hydroxyl functions of quercetin allowing selective glycosylation, followed by TEMPO-mediated oxidation to the glucuronide. This methodology enabled us to synthesize the five O-β-d-glucosides and four O-β-d-glucuronides of quercetin, including the major human metabolite, quercetin 3-O-β-d-glucuronide.     

Cl+F2→ClF+F和F+ClF′→ClF+F′反应机理的密度泛函理论研究

用密度泛函理论(DFT)B3LYP方法, 在6-311G基组下,计算研究了反应Cl+F2→ClF+F和对称反应F+ClF′→ClF+F′的机理。求得前者的过渡态为三角形,活化能为15.57 kJ*mol-1;后者的过渡态为线形和三角形,活化能分别为11.52和196.25 kJ*mol-1。结果均经过振动分析和IRC计算验证。     

丙三醇浓溶液玻璃化转变与结构松弛参数DSC分析

In order to examine the effects of water contents and heating/cooling rates on the glass transition and the structure relaxation parameters of glycerol/water mixtures, five aqueous solutions (60%, 70%, 80%, 90% and 100%) were investigated using the differential scanning calorimetry. Four scanning rates (10, 15, 20, 25 K/min) were used to obtain the glass transition parameters. The fitting results of plasticization constants indicated that Gordon-Taylor relationship could not be used effectively without considering scanning rates and that point on calorimetric step was chosen as the glass transition temperature. The specific heat changes during glass transition processes were relative not only to water content but also to heating rates. With the increasing of water contents in glycerol aqueous solutions, the structure relaxation activation energies and dynamic fragilities were decreased. Since the thermodynamic fragilities were increased with the increasing of water content, so the dynamic fragility and thermodynamic fragility were changed inversely if the water contents were changed in glycerol/water mixtures.     

Deuterodehalogenation—a mild method for synthesising deuterated heterocycles

We report a mild and efficient method for introducing deuterium into a range of heterocycles by reacting readily available halide analogues in a deuterodehalogenation reaction using D₈-IPA or Et₃SiD under palladium-catalysed conditions.     

The conversion of 2-cyano cyanothioformanilides into 3-aminoindole-2-carbonitriles using triphenylphosphine

2-Cyano cyanothioformanilide 3a reacts with triphenylphosphine in the presence of water to give 2-(cyanomethyleneamino)benzonitrile 4a, 2-(cyanomethylamino)benzonitrile 5, 3-aminoindole-2-carbonitrile 2a and (2-cyanoindol-3-yl)iminotriphenylphosphorane 6a. In the presence of p-toluenesulfonic acid in MeOH the reaction between 2-cyano cyanothioformanilide 3a and triphenylphosphine (2 equiv) gives 3-aminoindole-2-carbonitrile 2a in 90% yield. Under the same conditions 2-(cyanomethyleneamino)benzonitrile 4a gives anthranilonitrile 8a, 3-aminoindole-2-carbonitrile 2a and N-(2-cyanophenyl)formamide 9. In addition, substituted 2-cyano cyanothioformanilides 3b-f react with triphenylphosphine and p-toluenesulfonic acid in MeOH to give 3-aminoindole-2-carbonitriles 2b-f in 63-75% yields. Under analogous conditions 2-cyano-4,5-dimethoxyphenyl cyanothioformanilide 2g gives only 4,5-dimethoxyanthranilonitrile 8g and 4,6,7-trimethoxyquinazoline-2-carbonitrile 14g, but in refluxing dry PhMe in the absence of p-toluenesulfonic acid 2-cyano-4,5-dimethoxyphenyl cyanothioformanilide 3g, (2-cyano-5,6-dimethoxyindol-3-yl)iminotriphenylphosphorane 6g and 2-(cyanomethyleneamino)-4,5-dimethoxybenzonitrile 4g are obtained. The structure of 2-(cyanomethyleneamino)-4,5-dimethoxybenzonitrile 4g is supported unambiguously via independent synthesis and comparison to the isomeric 6,7-dimethoxyquinazoline-2-carbonitrile 15. All new compounds are fully characterised and a tentative mechanism for the transformation of 2-cyano cyanothioformanilides to indoles is proposed.