分子间作用力的学习进阶研究

研究分子间作用力的发展史、前沿应用和学情后设计分子间作用力的学习进阶、整体教学规划流程图、真实情境和教学设计,以培养学生关键能力与核心素养。研究认为,教师深刻的学科理解和对学生水平准确评估是设计进阶的基础,精选教学情境是促进学生关键能力和核心素养进阶的有力保障,使用实物模型和形象比喻是促进学生进阶的重要方式。     

基于科学思维学习进阶的高一元素化合物单元整体教学设计

以学习进阶理论为指导,以高一化学教材中金属铝在3个学习阶段的教学设计为例,在构建知识层级和认识层级的基础上,对元素化合物知识中的科学思维方法进行显性构建和整体安排,提出在化学学习中,尤其要注重科学思维的进阶学习,以更好地实现学习进阶的实质内涵,更好地培养学生的科学素养。     

基于提升学生科学论证能力的“元素周期律”进阶教学

以《化学2》中的"元素周期律"的教学设计为例,基于学习进阶理论建构高中元素周期律认识模型并设计学生进阶论证任务。通过学案上元素周期律的核心探究问题,驱动学生的"证据导向式"论证活动,在科学探究和数据分析的过程中,培养了学生基于证据和数据的实证研究意识,提升了学生逻辑推理和论证能力,以期为培养学生高阶思维的探究式教学提供案例参考。     

基于思维模型建构的“物质检验”初中复习教学研究

以让学生自主建构物质检验的思维模型为目标设计教学,通过完成物质检验的探究任务,学生自主建构思维模型,形成完整的思路,从而提高解决此类问题的能力。并在北京某中学初三年级进行教学实践,对教学实施效果进行了检验,根据教学实践总结出建构“物质检验”思维模型教学的有效教学策略：基于建模历程与生活情境选择素材;以学生为中心自主建构“物质检验”思维模型,引导学生经历多样化的思维发展过程;学生经历不同层级进阶的模型建构历程。     

烃同分异构体的计数

能否系统精确地解决高中化学学习中的同分异构体计数问题?本文在高中数学化学的背景知识之上,引入生成函数以及Pólya计数定理,在不考虑立体异构的前提下,从烷基的同分异构体计数入手,逐步推导烷烃、一烯烃、一炔烃苯的衍生物、二取代烷烃以及二烯烃的同分异构体计数的公式,并将计算结果与手工枚举进行对比,进一步证明其正确性。我们还归纳性地发掘了同分异构体计数的渐进特征并提出了以上烃类同分异构体计数的近似公式。对比国外的成果,本文尽力避免引入过多的数学概念,降低门槛,适合高中生阅读,加深对于烃结构的理解,培养计算思维;对比国内相同主题的研究,本文的推导形式清晰简洁,拓展性较强。     

基于模型认知的“价层电子对互斥理论”学习进阶设计*

遵循学生认知发展的客观规律,以及化学学科核心素养“模型认知”由低到高的水平划分,借助PhET互动仿真模型平台,通过虚拟的分子模型搭建和真实的分子构型对比,将“成键电子”“孤对电子”和“价层电子对”等抽象知识,融入认识模型、理解模型、运用模型和建构模型的递进式学习进阶设计中,在促进学生对互斥行为深度理解的同时,避免了虚拟可视化模型的过度类比可能导致的“相异构想”。     

师范生化学教学设计能力构成、水平层级及发展进阶研究

教学设计能力是师范生教学能力培养的重要组成部分。利用定性与定量相结合的研究方法从“教学设计知识”“教学设计技能”“教学设计态度与意识”等3个维度构建了师范生化学教学设计能力的构成模型及水平层级模型。开发了教学案例分析和问卷等2种测评工具对师范生化学教学设计能力进行实证研究,探查了师范生在“中学化学教学设计与实践”课程中化学教学设计能力的发展进阶。结果表明:师范生教学设计知识由单一发展为多样化,教学设计的技能从没有角度进阶到了多角度,教学设计态度与意识从不积极、不自信发展为积极且自信。     

进阶式分组任务在无机化学混合式教学中的应用探讨*

结合慕课平台、微信公众号和超星学习通,构建基于进阶式分组任务的混合式教学模式。基于各种信息技术,分别在不同的教学环节中,布置由易到难、由简单到复杂的进阶式分组任务,进行有效的混合式教学。教师通过多元反馈不断优化教学设计,通过师生互动促进有意义的教与学;学生在分组任务中通过不断探究与合作,提升学习能力。不同教学模式的教学效果的对比表明基于进阶式分组任务的混合式教学能提高学生的学习意愿,提升教学质量。     

学习进阶模型的构建及其应用——以中学化学课程标准内容文本分析为例

课程标准内容文本的2大核心问题：如何合理地选取核心内容,即确定内容标准;如何合理地制定表现标准。前者需要完成对概念学段的选取以及对概念本体的陈述,后者需要设定学生学习某概念后的学习表现以及这种概念和表现所对应的认识层级。而在一段时间内对“概念本体”“学习表现”“认识层级”3大要素的刻画回答的正是学习过程中什么在进阶,即心理构造的问题,这3者构成了学习进阶的要素模型。基于3要素的学习进阶要素模型可以用于评价学生的学习表现,也可以用于评价不同课程标准的文本陈述。     

基于SOLO分类理论的单元教、学、评一体化学习进阶设计——以“金属及其化合物”为例

针对目前化学课堂中存在的教学内容零散化、评价过程没有落实学生高阶思维能力发展的问题,以SOLO分类理论为依据,基于已有研究对教学内容进行概念优化整合,建构了 “金属及其化合物”单元学习进阶模型,进而以“钠及其化合物”为例设计了教学活动,然后根据教、学、评一体化的理念,设计了相应的教、学、评一体化评价框架。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

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.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

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.