新版高中化学教科书视觉表征的文本研究*

以人民教育出版社和山东科学技术出版社2019年出版的4本化学必修教科书为研究对象,借鉴Gkitzia等人开发的分析框架,运用内容分析法对4本教科书中的视觉表征进行分析。从表征的类型、表面特征的注释、表征与文本的关联情况、是否存在合适标题、多重表征内各层表征间连接情况等5个维度对教科书进行编码统计,获得新版化学教科书中视觉表征的信息。     

视觉表征视角下中学化学教科书编排的“三序”结合*——以“物质结构”相关内容为例

教科书的编排有其内在的逻辑结构,视觉表征是教科书的重要组成部分,因此视觉表征的选用也应遵循一定的原则。研究借鉴Gkitzia等人的分析框架对人教版初、高中化学教科书中“物质结构”相关内容的视觉表征进行编码分析。在对表征类型及功能分布分析的基础上,结合教科书中物质结构相关知识内容的编排及学生认知、心理发展规律展开讨论。研究发现,人教版教科书中视觉表征的分布与教科书编排的“三序”原则较为契合,能够针对不同学段、学生特点选用视觉表征。最后,依据研究结论,针对教科书中视觉表征的编选和使用提出建议。     

中韩初中《科学》(化学部分)教科书文本表征学习难度的比较

从文字表征、图像表征、图文表征3个维度的7个指标对我国浙教版《科学》教科书(化学部分)和韩国天才教育版的《科学》教科书(化学部分)进行了文本表征难度的比较。基于2个版本教科书编写的优点和值得商榷之处,从文本表征角度提出了初中《科学》教科书(化学部分)的编写建议。     

我国现行初中化学教科书视觉表征的文本研究*

正1研究设计借鉴Vasiliki Gkitzia等人建构的分析框架,从中抽提2个维度:表征类型(C1)、表征注释(C2)为分析指标(表1),采用内容分析法,对现行人教版、鲁教版、科粤版、沪教版、科普版和北京版初中化学教科书进行分析。由2位编码员对表征材料进行独立编码,一致性检验结果显示编码结果可信。     

我国高中化学教科书中“文化自信素材”选择的变迁

教科书承载着培养学生文化自信的重要使命。尝试从内容选材、呈现位置、表征形式、学科联系、知识载体等5个方面构建化学教科书中文化自信素材的分析框架,采用内容分析法对改革开放以来人民教育出版社出版的6版(共23册)高中化学教科书进行文本分析,揭示文化自信素材的特点与变迁趋势。以期为后续高中化学教科书中文化自信素材的选择与编写提供建议与参考。     

含CCl3"或CC"基团的酯类化合物的合成与表征

本文合成了六个含 CCl3"或 CC"基团的酯类化合物([Cl3CC(O)OCH2]2 1;p-(Cl3CC(O)O)2C6H4 2;(Cl3CC(O)O)3C3H5 3;(Cl3CC(O)OCH2)4C 4;Cl3CC(O)OCH2CCH 5;C6H5C(O)OCH2CCH 6)并对其进行了C/H分析、IR、1H NMR等项表征,对化合物5、6进行了质谱分析.     

微观表征视角下的高中《化学反应原理》教科书插图评价

采用文本分析法对人教版和鲁科版高中《化学反应原理》教科书中微观表征插图的使用情况进行分析。结果显示,2种版本教科书出现的微观表征插图数目均较少,微观表征插图主题内容均偏重“过程”,均只体现到部分重要主题,而且均缺乏“宏观-微观“表征插图。对如何合理认识微观表征插图的意义及系统规划微观表征插图的使用作出讨论。     

新中国成立以来我国中学化学教科书发展中的问题审视

中华人民共和国成立以来,中学化学教科书的发展可以划分为5个阶段。化学教科书发展中的主要问题有：社会政治、意识形态与化学教科书发展关系的问题;化学教科书中理论联系实际的问题;用先进化学知识充实化学教科书内容的问题;化学教科书中元素化合物和基础理论的编排关系问题;化学教科书中学科知识结构与学生认识结构的匹配问题;学习国外教科书编写的问题等。审视其发展中的问题,揭示其历史发展规律,可以为教科书的建设提供借鉴和启示。     

中美高中化学教科书“化学反应原理”模块微观表征插图的设计分析

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。     

一种新型卟啉-脂质体衍生物的合成及表征

采用人工合成的N,N-二.十六烷基-6-溴代-L-甘氨酰胺(BrC5Gly2C16H33)与5,10,15-三苯基-20-对羟基苯基卟啉(HPTPP)相连接,合成了一种新型卟啉-脂质体衍生物(P-L),用元素分析、紫外可见光谱、核磁共振、红外光谱以及荧光光谱等方法进行了表征,并对其谱学性质进行了研究.     

化学微观表征的方法与教学策略

将化学宏观现象进行形象、直观与动态的微观表征,能激发学生的学习兴趣,协助学生理解化学原理与规律。在几种不同形式的微观表征方法中,微观表征图能有效地消除相异构想,是建构化学三重表征的突破口,有利于化学三重表征的转化与融合。     

On the Similarity of DNA Primary Sequences Based on 5-D Representation

We propose a 5-D representation of DNA sequences based on the classifications of the four basic acid bases A,T,G, and C. The use of the 5-D representation is illustrated by constructing sequence invariants based on the entries in derived sequence matrices restricted to a selected width of a band along the main diagonal. As an application, we make a comparison for the first exon of β-globin gene sequences belonging to eleven different species based on the 5-D representation.     

Computation of electronic transition moments: the length versus the velocity representation

Summary We have compared transition moments (TMs) obtained using the length and velocity representations for transitions from the ground state of H₂ to the lowest two¹ _u and two¹ _u ⁺ Rydberg states, theA ¹–X ¹⁺ transition in BH, and theA ¹ _u –X ¹ _g ⁺ transition in C₂. For H₂, the TMs in the length and velocity representations agree well even in cases where the one-particle basis is incomplete and the TM has not converged. For BH and C₂ the TM in the length representation converges rapidly with improvements in the one-particle basis set and is insensitive to inner-shell correlation. In contrast, in the velocity representation convergence with improvements in the one-particle basis is much slower, especially for C₂, and the TMs are significantly changed by inner-shell correlation. Thus the difference between the TMs in the length and velocity representations would not appear to be a viable diagnostic of TM convergence.     

Sphericities of Double Cosets,Double Coset Representations,and Fujita’s Proligand Method for Combinatorial Enumeration of Stereoisomers

The concepts of double coset representations and sphericities of double cosets are proposed to characterize stereoisomerism, where double cosets are classified into three types, i.e., homospheric double cosets, enantiospheric double cosets, or hemispheric double cosets. They determine modes of substitutions (i.e., chirality fittingness), where homospheric double cosets permit achiral ligands only; enantiospheric ones permit achiral ligands or enantiomeric pairs; and hemispheric ones permit achiral and chiral ligands. The sphericities of double cosets are linked to the sphericities of cycles which are ascribed to right coset representations. Thus, each cycle is assigned to the corresponding sphericity index (a _d , c _d , or b _d ) so as to construct a cycle indices with chirality fittingness (CI-CFs). The resulting CI-CFs are proved to be identical with CI-CFs introduced in Fujita’s proligand method (S. Fujita, Theor. Chem. Acc. 113 (2005) 73–79 and 80–86). The versatility of the CI-CFs in combinatorial enumeration of stereoisomers is demonstrated by using methane derivatives as examples, where the numbers of achiral plus chiral stereoisomers, those of achiral stereoisomers, and those of chiral stereoisomers are calculated separately by means of respective generating functions.     

Spectral representation of reduced protein models

We consider a spectrum-like two-dimensional graphical representation of proteins based on a reduced protein model in which 20 amino acids are grouped into five classes. This particular grouping of amino acids was suggested by Riddle and co-workers in 1997. The graphical representation is based on depicting sequentially the amino acids on five horizontal lines at equal separations. One-letter codes, B, O, U, X and Y, to which numerical values 1 to 5 have been assigned, are suggested as labels for the fictional amino acids that represent all the amino acids within each group. The approach is illustrated on ND6 proteins of eight species having from 168 to 175 amino acids. While visual inspection of the novel spectral graphical representations of proteins may reveal local similarities and dissimilarities of protein sequences, arithmetic manipulations of spectra offer an elegant route to graphic visualization of the degree of similarity for selected pairs of proteins.     

国外关于化学概念的多元外在表征的研究述评

对国外近15年以来关于学生学习化学概念的多元外在表征做一综述,阐明多元外在表征与化学概念的定义,总结了学生关于化学概念的多元外在表征的特点:这些多元外在表征以计算机为基础,特别是计算机模型比较多;在计算机动画或者模型中,侧重分子水平上的表征即微观表征。进而得到化学概念的多元外在表征的教学启示:教师应该注重化学概念的多元表征教学;各种多元外在表征呈现给学生时要结合学生的实际情况;教师和课程的设计者可以考虑早期引入一些基本的微观表征,以配合探索物质的宏观性质。     

Study of molecular orbitals in momentum space

Molecular orbitals are presented in configuration and momentum representations. We propose to minimize large oscillations present in calculated momentum wavefunctions by cancelling position factor phases. We illustrate the distortion introduced by different electron translation factors and show continuum states and dynamical wavefunctions in momentum coordinates. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001     

Transformation of Bloch representation into atomic orbital representation and combined matrix element calculation technique for spatially bounded basis functions in crystals

A method is proposed for transforming the Hamiltonian from Bloch to atomic function representation. For spatially bounded functions, this is a rigorous method based on solution of a certain algebraic system of equations. Unlike the conventional procedure based on integration over the Brillouin zone, the new method requires knowledge of the matrix elements of the Bloch representation only at several points of the Brillouin zone. The number of these points is determined by the trimming radius for the spatially bounded functions and by the lattice constant. The method can be used for calculating matrix elements in a basis of atomic functions and for reducing computations in matrix element calculations of the Bloch representation for procedures using numerical integration.     

New 2D graphical representation of DNA sequences

We consider a 2D graphical representations of DNA sequences, which avoids loss of information associated with crossing and overlapping of the corresponding curve. We outline an approach, which is based on the construction of a three-component vector whose components are the normalized leading eigenvalues of the L/L matrices associated with DNA. The examination of similarities/dissimilarities among the coding sequences of the first exon of beta-globin gene of different species illustrates the utility of the approach.