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1.
基于Flow Map对中美4种教材"氧化还原反应"内容难度的定量统计表明,中美教材的整合广度和表征深度的差异明显,美国教材的整合广度和表征深度均明显大于中国教材,即美国教材的相关难度较小;质性评价表明,美国教材以"化学变化中的电子"为认识核心,构建了"得失氧-氧的电负性与电子得失-氧化数与电子得失"的认知脉络,采用"电负性"作为先行组织者,更多运用对比与比较、情境推理与解释等信息处理策略,整合了大量的氧化还原反应应用类的知识。  相似文献   

2.
肖笛  熊言林 《化学教育》2019,40(7):9-15
以新加坡初中化学Chemistry Matters教材为研究对象,对教材中涉及的实验案例、实验类型及数量进行了统计。结合新加坡新版科学教学大纲及PISA测试,从教材实验的内容选取、设计意图、呈现方式等方面进行分析,并对教材实验部分蕴含的核心素养进行一定程度地挖掘。研究得出:Chemistry Matters教材中实验的设置具有"内容选取彰显与时俱进,设计意图注重学以致用,呈现方式突出图表结合,活动过程强化问题引导"等特点。  相似文献   

3.
基于“宏观辨识与微观探析”核心素养,对“烃及其衍生物的性质与应用”主题下的新旧人教版教材思考类栏目进行分类和比较分析。结果显示,新教材的内容设计更贴合新课标要求,相对旧教材在素养水平分布、认识视角外显化和符号表征规范化等3个方面有显著差异。基于此,对新教材的使用提出了4点建议:转变传统认知,重视指导与评价功能;把握教材逻辑,实现认知结构化功能;注重符号表征,发挥新教材规范功能;融合优选情境,落实新教材育人功能。  相似文献   

4.
陈莲  万莉 《化学教育》2019,40(9):19-23
科学精神是中国学生发展核心素养的重要内容之一,不同教材对科学精神的体现不同。从理性思维、批判质疑、勇于探究等3个方面对中美2种初中化学教材中"原子"内容进行对比分析,为教师对教学内容的二次加工提供建议。  相似文献   

5.
第二届国际富勒烯科学与技术多学科会议于1996年7月7口~Ic[l在英国牛津大学召开。与会代表170人,分别来自美国、英国、法国、德国、日本、中国等用个国家和地区。我国大陆出席会议8人,台湾及香港地区各2人。富勒烯的发现者H.W.Kroto、R.E.Smalley及一些活跃在富勒烯研究前沿的科学家参加了会议,并在会上做了邀请报告。大会报告ZI篇、墙展136篇。我国有大会报告1篇、墙展11篇。与首届会议相比,此次会议不但与会人数及提交的论文数量有所增加,而且在研究广度和深度方面均获得了重要进展,进一步显示出富勒烯研究是一个充满活力…  相似文献   

6.
为了有的放矢地完成大学化学的教学,将新课程高中化学教材和大学化学教材作对比,逐一总结归纳高中化学和大学化学相联系的知识点,并介绍知识点深度、广度的差异,使大学化学教师更好地了解高中化学教材内容。  相似文献   

7.
以化学反应原理内容为例,对中国人教版高中化学教材和美国高中化学教材Chemistry:Conceptions and Application习题中的情境创设进行比较研究,发现2者在情境性习题的主题分布与占比、情境素材来源分布、问题与情境的融合度等方面存在明显差异。  相似文献   

8.
李小峰  郑长龙 《化学教育》2021,42(17):24-31
概念转变理论、认知架构理论、概念形成理论都验证了核心概念建构的重要性。基于核心概念建构的进阶路径,介绍了学生理解“物质”概念进阶表征框架、“物质”和学生能力水平进阶表征框架、“物质”结构的学习进阶表征框架、“物质”核心概念区块理论表征框架和“物质”概念描述理论表征框架,并以“水的认识”为例分析了其构造图和结果空间。基于美国、英国、澳大利亚、爱尔兰、新加坡、加拿大阿尔伯塔省、加拿大安大略省、中国台湾、中国大陆9个国家或地区1至9年级科学课程文件,梳理了学生“物质”核心概念,并从“成分与辨识”“性质与应用”“变化与转化”3个视角划分了学生“物质”核心概念进阶维度,介绍了“物质”核心概念进阶测量方法,以期对我国科学教育有所启示。  相似文献   

9.
微观表征插图是重要的化学教学素材,是学生对三重表征在头脑中加工内化的重要认识媒介。为了能在“化学反应原理”模块教学中更好地发挥微观表征插图的价值,通过内容分析法,对中国人教版高中化学教科书和美国高中化学教科书Chemistry: Concepts and Applications在此模块的微观表征插图设计进行了比较分析。结果显示,2种版本教科书中的微观表征插图在该模块插图总数中的占比较少,呈现最多的主题内容均为过程微观表征;缺少“化学反应的方向、限度和速率”主题的微观表征插图;2者表征的形式水平较高,但美版教材更好地融合了“宏、微、符”3类表征。最后,基于分析结果对教科书“化学反应原理”模块中微观表征插图的设计与使用提出了相关建议。  相似文献   

10.
在卤代烃的课堂教学实践中,选定1-溴丙烷为代表物,依据化学键理论并结合模型认知、实验探究等方式创新设计课堂教学,既规避和弥补按某些教材教学带来的尴尬与不足,又能突破教学难点(卤代烃消去反应原理),更能培育"宏观辨识与微观探析""证据推理与模型认知""科学探究与创新意识""科学态度与社会责任"等学科核心素养。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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%).  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
19.
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 CuI 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).  相似文献   

20.
(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.  相似文献   

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