基于四段式诊断工具测查高一学生“物质的量”迷思概念*

使用四段式测验对116名高一学生进行“物质的量”迷思概念测查,共诊断出10个典型的真性迷思概念。结果表明学生缺乏对物质的量及其相关概念的本质理解,尤其是在物质的量定义上。学生尽管在测试中表现出过度自信,但能清楚认识自身在概念理解上的不足。信心指数在判断迷思概念的性质与了解学生对概念的元认知方面具有重要作用。     

国外化学键迷思概念研究对我国高中化学键教学的启示

化学键是高中化学物质结构理论的重要组成部分。介绍了国外化学键迷思概念的研究进展,为我国高中化学键教学的有效实施提供借鉴和启示。     

基于本体分类法的化学键迷思概念转变研究*

基于概念本体分类模型,以化学键相关内容为载体,详细阐述化学概念本体分类模型的内涵,以及在化学迷思概念转变中的应用。同时,从本体论的视角讨论本体分类法可作为化学概念教学的新的补充。     

高中生与化学热力学有关的迷思概念研究

通过问卷探查高中生学习化学热力学过程中易产生的迷思概念，并通过开放性试题和学生访谈，归纳出相关迷思概念具有普遍性、相关性、隐蔽性和经验性的特点，然后从化学热力学概念的抽象性、教材对热化学理论的回避、教师对学生认识过程的关注程度和学生知识储备4个方面分析了迷思概念产生的主要原因，最后得出结论。     

化合物与混合物迷思概念检测工具的发展与诊断

通过谈话、问卷调查等研究方法设计化合物与混合物迷思概念的二段式检测工具,分析辽西地区九年级学生化合物与混合物迷思概念的主要类型,归纳为生活经验型、名词产生型、概念混淆型和宏微错位型等4个方面,并且从性别、所在地区等方面探讨影响迷思概念的外在因素.对获得的数据结果进行spss13.0统计分析.     

“化学键”学习方法探析

化学键既是学习的重点,又是学习的难点.针对高中化学"化学键"的教学中学生对化学键的学习感到抽象难懂的实际,从认识和把握化学键概念、利用概念固定点和促进概念同化等方面进行了探讨.     

基于元认知理论的化学键概念应用问卷开发

为了测量高一学生在应用化学键概念时元认知的参与程度,设计了基于元认知理论的化学键概念应用问卷。该问卷包括共价键和离子键2个基本概念,每个基本概念包括5道封闭式题目。在每道封闭式题目之后追加2个开放式任务,用于测量学生应用化学键概念时元认知知识和元认知监控的参与程度。对已经学过化学键概念的高一学生进行测试后的调查数据分析表明,该问卷具有较高的内部一致性,并具有较好的信度和效度指标。因此,该问卷可作为一种测量学生应用化学键概念时元认知参与程度的工具,并具有较强的应用价值。     

促进概念转变的科学课堂教学研究——以“化学式”概念教学为例

促进概念转变是课堂教学的关键。通过对概念转变原理和概念表征的嬗变分析,以"化学式"概念教学为例,提出了一种具有普遍意义的概念教学结构,具体包括"激活前概念、修正完善概念、建立概念模型、厘清迷思概念、活化科学概念"5个教学过程。在实际课堂中,这一概念转变链必须与认知逻辑链、组织形式链有机对应,才能有效促进概念的转变。     

高中生对“物质的量”概念群的理解水平测查

通过编制信度、效度可靠的测量工具对高中生“物质的量”概念群的理解水平进行测查,发现大部分学生主要处于部分理解并伴随一定的误解的理解水平;学生对各概念的理解均存在迷思概念;学生在“物质的量”概念群中的迷思概念共计14条。     

化学键的高选择性拓扑指数及应用

基于分子和原子的高选择性拓扑指数, 提出了化学键的高选择性拓扑指数bATID. 分别采用300余万个化学键的虚拟数据集和实际数据集检验bATID的唯一性, 未发现简并, 即bATID具有较强的化学键区分能力. 进一步将bATID应用于有机化合物的化学键识别, 获得了较好结果. 如, 利用bATID可识别出富勒烯C₆₀的90个化学键为30个6∶6键和60个5∶6键. 研究还表明, bATID的化学键识别可应用于手性中心自动设定和自同构群穷举生成的顶点置换.     

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.