中学化学中绿色化学教学的问题与对策

通过访谈发现,教师在呈现绿色化学时缺乏恰当的教学策略,学生对绿色化学内涵的理解比较浅薄。针对此问题,多次同课异构比较和分析的结果表明：教师应在教学设计时,多关注科技前沿的最新成果,以系统的、整合的方式呈现给学生真实的问题情境;在教学实施时,应激发学生内在动力,多维度地看待绿色化学,才能让绿色成为学生科学画卷的底色。     

剖析师生对绿色化学的认知偏差

在绿色化学思想逐渐普及的同时,发现许多学生和教师对“绿色化学“和“绿色化学实验”的认知存在偏差。学生错误地认为“绿色化学”就是任何时候都禁止排放任何废物的化学;教师错误地认为：实施绿色化学实验教学时,不能向教室或实验室泄漏一丁点废气,致使学生的嗅觉等感官体验被剥夺,造成他们对事物的感知不完整。     

化学学科中将抽象知识具体化教学的抽样研究

1问题的提出 作为一名化学教育者,教了多年的化学,本人发现在化学教学中存在着一种“怪现象”：几乎每一届学生当中总有一部分学生,在学习化学课程中一些较具体的内容时,如：氧气的性质、氢气的性质等等,成绩都比较理想,甚至可以称得上是优秀;可一旦遇到相对抽象的内容时,如：物质结构、物质的量、溶解度等,化学成绩就会明显下降,甚至变得非常糟糕。     

发现化学之美 感悟科学魅力

本文指出化学教学的关键,在于引导学生发现化学之美,感悟科学魅力,激发学生的学习兴趣及创造潜能。全文阐述了化学的外在美、揭示了化学的内在美———化学学科思想 (科学之美 )、崇尚化学家的人生之美及化学教师的人格之美。作者认为：化学教师的人格之美源自“以学生发展为本”的教育理念和对学生及化学教育事业的挚爱。本文旨在倡导广大教师更新教育观念,增强自身素质,升华崇高人格,真正实现化学教学中“教师快乐教学,学生享受学习”。     

关于《现代化学教学论》教材建设的思考

现代化学教学论的目标应包括 3个层次 ,即通过学习 ,要引导学生 :一是获取有关化学教学的理论知识 ;二是具有化学教学的实践能力 ;三是能从事化学教学科学研究。而无论哪个层次的学习都应该通过学生参与教师精心设计的实践活动而获得 ,因为只有当学生被鼓励参与有关化学教学问题的探讨并付诸于行动时 ,他们的学习最为有效。因此 ,化学教学论的教学 ,在教学观念上 ,应倡导开放、民主 ;在教学过程中 ,应强调自主、体验 ;在教学形式上 ,应以学生活动为中心 ;在教学方法上 ,应以探究学习为基础。这种以学生为中心、以探究为基础的学习所形成的价…     

在初三开展化学课外活动的一些做法与设想

化学课外活动是化学课堂教学的延伸、巩固和发展;是化学教学全过程的一个重要部分;是培养和发展学生智能的重要途径。教学大纲明确要求：“要指导爱好化学的学生在课外进行一些化学科技活动。”化学课外活动的形式多种多样,我们认为,其主要形式是化学课外实验活动小组。     

化学实验教学中的“思想实验”及其教学价值研究

从教师的实验设计、学生的实验准备、教科书等3个维度探查了化学实验教学中恩斯特·马赫所定义的"思想实验"的成分。在此基础上分析挖掘了"思想实验"的教学价值,即教师可借助思想实验优化实验教学设计;学生可借助思想实验优化实验准备问题;教师可用思想实验来彰显化学学科魅力。     

基于证据推理的“化学反应的方向”教学

在分析“化学反应的方向”的教学内容和相关教学设计的基础上，创新设计焓判据证伪实验、熵判据证伪实验以及氯化铵分解实验。通过分析实验结果寻求证据，强化证据意识，逐渐揭示化学反应方向的复合判据，促进学生深度认识化学反应的方向，发展学生的证据推理素养。     

我们为什么要辅导高中化学竞赛

当前背景下的全国高中学生化学竞赛对推进教育改革、培养优秀创新人才有积极的作用。辅导化学竞赛的初衷是：为了学生的才能发展;为了彰显化学的科学思想和研究方法;为了学生顺利升入理想的大学;也为了教师的专业发展。     

科学教学的价值

正(刘知新读书札记)教学价值就是教学活动和主体需要的关系,即教学应该满足主体的需要。科学教学(化学教学是它的一个分支)发展到今天,应体现科学主义与人文主义的教育思想互补、为学生可持续发展服务的基本要求。《化学教学论》一书曾从化学教育是教育系统的一个子系统;化学教育是一种全社会参与的行动;化学教育是一种启智育人的内容;及化学教育是一种社会预期的成果等4个方面讨论过化学教育的社会价值。     

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.