基于项目式学习的高三化学实验和工艺流程专题复习*——以“海带中碘的提取”为例

以“海带中碘的提取”为例,提供文献让学生课前阅读,完成“海带中碘的提取”流程设计,并进行成果交流。在此基础上,进行方案实施,并进行总结评价。研究结果认为,将知识与实践结合,能够激发学生探究热情;将自主文献研究、方案设计、实验验证结合,可以培养学生的科学探究和创新能力;应该注重教-学-评一致性;需要进一步提高教师的实验实际操作能力和知识引导能力。     

化学学科核心素养导向的教学实践改革思考*——基于2019版AP化学课程标准的分析

《普通高中化学课程标准(2017年版)》的颁布,开启了我国化学学科核心素养导向的教学实践的新时代。美国高中阶段实施的2019版AP化学课程凸显科学实践的课程目标,以4个化学大概念为依据选择、组织课程内容,倡导教、学、评一体化的教学策略,开展以学生为中心的引导性探究实验,设计多样化的评价任务。对比我国现行化学教学实践中缺少大规模教、学、评一体化平台,科学解释和论证能力目标外显不足,教师难以建立化学知识与学科观念素养间联系的现状,提出聚焦课程目标建设过程性评价体系,深度挖掘教学内容背后的科学解释和科学论证能力要求,深入理解知识承载的认识功能和价值等思考。     

自主探究交互软件在“物质的量”教学中的应用

探讨了"物质的量"教学中存在的主要问题,提出应用自主探究的交互教学软件,以探究活动为依托,以培养学生科学研究方法和逻辑推理能力为主旨,从学生已有的知识和经验出发,通过具体的可理解和可操作的问题入手,形成任务并在任务驱动下实现学生自主探究,得到结论、建立概念和导出公式。实践表明,该方法能有效帮助学生建立有关摩尔的概念和计算公式,消除对概念的迷茫,并在定量科学研究方法培养中有一定的作用。     

基于项目学习的高中化学教学设计与实践*——以“探究食品脱氧剂中的化学问题”为例

以“探究食品脱氧剂中的化学问题”为项目学习主题,以探究食品脱氧剂的主要成分、脱氧原理、能量转化形式为项目学习活动,呈现了基于项目学习的高中化学教学设计思路、教学流程,进行了项目教学实施,并结合前后测、学生自评互评和教师评价量表从知识、能力、素养等方面分析了实施项目教学后的效果。     

高中化学“次氯酸盐的性质”的项目式教学*——84消毒液的使用指南

以“84消毒液的使用指南”为主题,开展高中化学“次氯酸盐的性质”的教学。学生通过完成“一张图说清消毒剂”“探究84消毒液的漂白效果与酸碱性的关系”“探究84消毒液的漂白效果与光照的关系”“探究84消毒液的漂白效果与温度的关系”“84消毒液与酒精混合会有氯气吗”等5个项目任务,理解了次氯酸盐的性质及漂白原理,培养了学生的文献检索能力、实验探究能力以及发展了学生的高阶思维能力。将文献查阅与学生实验相结合,让学生在真实问题的解决中,完成次氯酸盐的性质等相关知识的内化,是顺利完成本项目教学的关键。     

基于WWHW认识论思考模型的“化学反应速率”创新实验教学设计

化学反应速率是高中化学重要的原理性知识。巧妙使用多功能组合U型管设计创新实验,探究化学反应速率影响因素,提高学生实验能力,增强学习兴趣。以WWHW认识论思考模型为指导,帮助学生自主建构化学反应速率相关知识,深化学生对化学反应速率知识内容及其科学本质的理解。     

“金属的电化学腐蚀”教学设计创新

以学科理解为基础,注重创设真实的教学情境,创新实验设计,使学生在探究暖贴发热原理和钢铁腐蚀原理的过程中获得金属电化学腐蚀的知识,拓展认知结构,学习科学方法,发展科学探究能力。     

高中化学实习教师探究性教学水平个案分析*——以“氧化还原反应”主题教学为例

实验探究与创新意识是《普通高中化学新课程标准》倡导的化学学科核心素养之一,因此,师范院校培养职前教师探究性教学能力对于其职后专业发展具有重要作用。以一位化学教师为研究对象,应用探究性教学水平测评量表--EQUIP表对其实习“氧化还原”3节实录课例进行探究性教学水平评估,并辅以CCITIAS量表进行量化分析,以便探讨研究对象的探究性教学行为表现特点。研究结果如下:(1)研究对象具有一定探究意识,但是探究实践水平还在萌芽期;(2)当重复大学模拟课堂教学经验时,其探究水平表现较高,研究对象的探究理念转化为实际探究性教学的活动策略的能力较强;(3)如果对新授课缺乏经验,则教学行为仍然以知识为中心,但是与学生有一定的积极互动;(4)研究对象对不熟悉的探究教学策略采取回避态度,基本采用传统授课模式。     

基于结构化认识和解决物质转化问题的思维模型建构*——以“氢氧化钠变质的实验探究”为例

以探究氢氧化钠变质为依托点,融合酸、碱、盐相关知识,在复习知识的同时,将结构化认识和解决物质转化问题的思维方法贯穿于课堂实验探究始终,帮助学生从“概念理解-模型建构-学习活动-真实问题-模型评价”5个维度,体验模型认知的具体过程。利用实验探究的手段解决学生的认知冲突,修正和完善模型,实现结构化认识和解决物质转化问题的思维模型建构,提升化学学科核心素养。     

变量控制在实验探究专题教学中的应用与评价*——以“镁+水”反应体系为例

在以“Mg+H₂O”反应体系为核心的实验探究专题教学活动中,通过变量控制的方法设计实验方案,采用常规实验、数字化实验等方式,多层次探究加速“Mg+H₂O”反应速率的原因和控制条件。在有层次的教学活动中递进式发展学生通过变量控制的方法设计实验方案的能力、拓宽对影响化学反应速率因素的认识角度,通过对活动环节的评价,诊断并发展学生的实验探究能力。     

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.     

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.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.