科学思维导向的物理化学实验教学模式*

物理化学实验课程的教学目标正逐步从“培养学生的实验能力”向“培养科学思维”进行迁移并不断挑战传统的实验教学模式。基于这一理念,在物理化学实验课程中尝试引入探究性实验和论文式报告相结合的教学模式以重构学生的学习过程。实践结果表明:探究性实验和论文式报告在物理化学实验教学中相辅相成,让学生在探究性实验中再现知识的创造过程并以科技论文的形式对探究结果进行评价和交流,进而培养其科学思维方法和创新意识。此外,该模式重视科学知识的实验起源,鼓励学生在“写以致学”过程中实现知识的整合、迁移乃至创新。     

物理化学课程内容的编排顺序：基于“学科思维-认知规律”双重视角的观察

物理化学课程内容的编排顺序是物理化学教学中的核心问题之一,教指委发布的《化学类专业化学理论教学建议内容》对其并未明文规定,经典教材对此处理各有不同。经过对比和分析不同经典教材的编排顺序差别,可以看出物理化学的学科思维和认知规律是决定编排顺序的两大原则。依据学科思维从空间、时间、体系等3个维度为物理化学课程的核心内容画出逻辑关系图,并结合认知规律提出了多种编排内容的方式。     

物理化学课堂教学中的兴趣教育

针对大学物理化学难度较大的特点,介绍了课堂教学中实施兴趣教育的方法和体会。通过将抽象概念和理论与学生熟悉的背景知识相联系,与生产生活、其他化学课程、化学实验及学科前沿相结合,可大大提高学生的学习兴趣,激发学生的创新思维,调动学生分析问题、解决问题的主动性和积极性,从而提高物理化学的教学质量。     

改进教学方法提高教学效果

物理化学概念抽象,理论严谨,学生难于理解和记忆,学生普遍反映物理化学难学.本文作者通过20多年的教学实践,总结了一套较好的课堂教学方法,根据学生好奇、求知欲强、思维活跃、学习从兴趣出发的特点,充分利用物理化学内容丰富、趣味性强的特点,努力挖掘各种趣味因素,通过更新教学手段,改进教学方法,创设情境,以各种教学形式诱发、激励学生的学习兴趣与求知欲望,使他们由被动的"要我学"转变为主动的"我要学",从而搞活了教学,取得了较好的教学效果.     

情境化教学在物理化学教学中的运用

结合医学院校物理化学教学过程中的实践与体会,以春、夏、秋、冬四季中各具代表的生活场景为例,创设情境化教学,激发学生学习兴趣,用物理化学的思维方式,自主探究解决现实问题,最终帮助学生完成知识结构的搭建。     

物理化学混合式教学设计与实践——以“单组分系统相变热力学”为例*

以“单组分系统相变热力学”为例介绍了物理化学混合式教学设计与教学实践。围绕课程教学目标,在课前、课中、课后的每一个教学环节中践行课程教学理念,通过“问题+案例”方式突出物理化学基本方法的应用性、普适性与前沿性,让学生在教学过程中获取原理、体验探究、发展思维、生成智慧。教学评价结果显示,绝大部分学生对混合式教学模式给予了积极的评价。     

创造性思维在化学实验设计教学中的应用研究

在化学实验教学过程中,教师如能综合运用创造性思维方法进行教学,加强对学生进行创造性思维方法的训练与指导,就有可能培养出具有创新能力的学生;把进行化学实验设计时的思维过程和方法教给学生,使学生能够运用创造性思维方法去寻找完成化学实验设计的最佳途径。这2项教学举措对培养学生的创造能力是大有裨益的。     

基于SPOC和慕课堂的物理化学实验混合式教学改革实践

为了提高物理化学实验的教学效果,拍摄制作了物理化学实验原理和操作视频,并基于爱课程(中国大学MOOC)平台的SPOC和慕课堂,开展了线上线下混合式教学。实践证明,混合式教学提高了学生的积极性,提升了学习效果,增加了师生之间的互动,可以进一步培养学生的综合能力,激发学生的创新思维。     

无机化学与物理化学课程的协调教学

根据无机化学和物理化学的内容设置及特点, 结合教学实践, 探讨了2者在教学过程中的有机配合和协调统一。无机化学教学应以知识的衔接和实际应用为主, 而物理化学教学则要侧重知识点的挖掘和提升。2者的协调有助于提高课堂利用率, 促进学生学习能力和科学思维的培养。     

发展学生思维能力的训练途径

教师应引导学生对化学事实、现象进行分析、综合、抽象、概括等思维活动 ,逐步发展学生的思维能力和创新意识 ,提高他们的思维品质 ,从而开拓学生学习的思路〔1〕。教学实践表明 ,思维品质优劣直接影响着学生学习能力和学习水平的提高。心理学研究成果表明〔2〕:思维发生和发展中所表现出来的个性差异就是思维品质 (深刻性、广阔性、敏捷性、灵活性和创造性等 ) ,发展和培养学生思维品质是发展思维能力的突破口。化学教学中怎样发展学生的思维能力 ?提高思维品质的训练途径和方法如何 ?是需要认真探讨的问题。1　引导学生通过变式 (多变、多…     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.     

Catalyst free,visible-light promoted photoaddition reactions between C60 and N-trimethylsilylmethyl-substituted tertiary amines for synthesis of aminomethyl-1,2-dihydrofullerenes

An efficient and benign method for the preparation of aminomethyl-substituted fullerenes has been developed. The process, involving catalyst free, visible-light irradiation of 10% EtOH-toluene solutions containing fullerene C₆₀ and N-trimethylsilylmethyl-substituted amines by using a 20 W compact fluorescent lamp, leads to formation of aminomethyl-substituted fullerene adducts in a highly efficient manner. The photoaddition reaction takes place via a pathway initiated by visible light absorption by C₆₀, followed by SET from the amine to the triplet excited state of C₆₀. Ethanol-promoted desilylation of the resulting a minimum radical then generates the corresponding α-amino radical which couples with the C₆₀ radical anion to form the anion precursor of the fullerene adducts. The new approach using visible-light takes place under mild conditions and it does not require the use of photocatalysts. Thus, the method developed in this effort could broadens the range of functionalized fullerene derivatives that can be readily prepared.     

Highly efficient and stereoselective cycloaddition of nitrones to indolyl- and pyrrolylacrylates

The reactions of various nitrones with indolyl- and pyrrolylacrylates proceeds regioselectively with high diastereoselectivity in the case of aldonitrones, and represents an effective method for obtaining new indolyl- and pyrrolyl-substituted isoxazolidine carboxylates stabilized by weak (CH?O) and moderate (NH?N) strength intramolecular hydrogen bonding. The resulting cycloadducts exhibit promising in vitro anti-influenza activities.     

Transition metal-free direct amination of benzoxazoles using formamides as nitrogen sources

A transition metal-free method for the direct amination of benzoxazoles using formamides as nitrogen sources is reported, which was mediated by an inexpensive and environmentally friendly tetrabutylammonium iodide/tert-butyl hydroperoxide system and gave the 2-aminobenzoxazole derivatives with moderate to good yields.     

l-Proline-catalyzed five-component domino reaction leading to multifunctionalized 1,2,3,4-tetrahydropyridines

Multifunctionalized 1,2,3,4-tetrahydropyridines are concisely synthesized in good yields via l-proline-catalyzed or l-proline/FeCl₃-cocatalyzed one-pot multicomponent reactions (MCRs). The MCRs involve a domino hydroamination/prins reaction/Mannich-type reaction/intramolecular dehydration-cyclization process. The molecular structure of 5baa, one of multifunctionalized 1,2,3,4-tetrahydropyridines, was confirmed by single-crystal X-ray diffraction.     

Exploring the scope of the Gewald reaction: Expansion to a four-component process

An efficient four-component reaction was developed to take advantage of the reactivity of the 2-aminothiophene-3-carbonitrile functionality, which is obtained during the classical three-component Gewald reaction. Various α-methylene bearing ketones were reacted with malononitrile, elemental sulfur, and aryl/heteroarylnitrile derivatives in t-BuOH/NaOH to afford 2-arylthieno[2,3-d]pyrimidin-4-amines in high yields. Preliminary studies revealed the photophysical properties of the products and their potential for use as metal sensors.