中澳化学教材中习题的比较研究*——以“金属”为例

以“金属”一章为例,对人教版高中化学教材和澳洲VCE课程的高中化学教材中习题进行比较研究,发现澳洲化学教材中的习题对学生的认知水平要求更高,能帮助学生进一步改变学习方式,更好地促进学生形成学科观念,加强学科思维训练,注意学科方法应用。     

加拿大高中化学教材中单元引导语的编写特点研究*——以Nelson(尼尔森)出版社Chemistry 11为例

正中学化学教材中的"引导语"指的是每个单元的开篇之作、点睛之笔,它既是教材必不可少的组成部分,又是统领各个单元的纲领性文字。引导语的存在既能为学生的学习提供基本的框架和思路,又能对教师教学起到引导作用。其功能包括:引导学生明确学习方向的导向功能,激发学生学习兴趣的激励功能,作为先行组织者去检验学生学习情况的检测功能。教材中的引导语非常重要,但我国对于此方面的研究甚少。因此,     

化学教学中引导学生“用教材学”的具体做法

化学教学应以教材为基点,引导学生"用教材学",以提升学生的认知水平,学习分析与解决问题的科学方法,建构化学基本观念。结合教学实践阐述了引导学生"用教材学"的3种具体做法及其意义,包括学案承载设问、探讨图表功能、研析教材内容。     

基于科学思维学习进阶的高一元素化合物单元整体教学设计

以学习进阶理论为指导,以高一化学教材中金属铝在3个学习阶段的教学设计为例,在构建知识层级和认识层级的基础上,对元素化合物知识中的科学思维方法进行显性构建和整体安排,提出在化学学习中,尤其要注重科学思维的进阶学习,以更好地实现学习进阶的实质内涵,更好地培养学生的科学素养。     

教师备课时对教材中隐含课程资源的开发和利用

现行的高中化学教材中,设置了丰富的隐含课程资源,在备课时教师要深入研究教材,充分挖掘开发这些隐含课程资源,结合所教学生的实际情况实施教学,以满足不同层次学生的学习需求,充分开发学生的智力,培养学生的学习能力;如此,教师才能用好、用活教材,进一步完善教材,并促进自己的专业发展。     

中美初中化学教材实验和探究栏目编写的比较研究

初中阶段是学生学习化学的启蒙阶段,能否编制适合学生认知水平和兴趣的化学入门教材,对今后学生学习化学起着至关重要的作用。通过分析比较中美2套初中化学教材中实验和探究活动的编写特点,为我国初中化学新课程标准的实施和新教材的进一步修订和编写提供参考。     

分析化学教学中知识点的树结构设计

依据中心教学法,通过对教材的深入分析和知识重组,设计和建立了分析化学中化学分析理论教学的知识点树结构图,该结构图以误差为主线,贯穿了教材整个内容的各个知识点。教学中着重于各知识点及其相互联系和思维方式的介绍,课后辅助各章节知识点总结归纳,以便于学生对整体知识的理解、自我建构和学习方法的掌握。     

支撑自主建构强化能力形成——韩国高中化学教材化学热力学内容编排的启示

化学热力学的相关知识对学生认识化学反应中的能量变化、理解化学反应方向与限度起着至关重要的作用,但一直是高中化学学习中的难点。教材的编排方式直接影响到学生的学习难度和教师的有效教学。韩国高中化学教材化学热力学知识编排运用多种直观呈现方式,降低学习内容的抽象性;依据学生认知特点层层递进呈现知识,从而降低学习难度;运用实验教学、渗透STS教育等方式培养学生科学探究能力和知识运用能力。这些特点都值得我国高中化学教材借鉴。     

基于课程标准的教学——以常见阴、阳离子的检验为例

以常见的阴、阳离子的检验为例，研究了如何实施基于标准的教学。校本教材的开发为标准、教材、教学、评价的一致性提供保障；以学生应知的和能做的驱动课堂活动；根据达成标准应有怎样的质量表现，试卷编制先于教学设计。课堂上，“教”“学”双方都明确学习目标，教师提供多种策略来满足学生多样的学习需要，如提供工具，搭建脚手架，并以“微”研究性学习的方式展开教学，给学生提供了充分的进步空间。     

中美化学教科书对"促进学生概念转变"的差异分析

概念转变在近年来的科学教育中备受关注,教科书作为重要的教学资源对于学生转变概念进行化学学习能起到怎样的作用? 以Roth"科学教科书促进概念转变的原则"为框架,对上海地区通用的化学教材和美国高中主流理科教材"Chemistry:Concepts and Applications"进行对比,分析中美化学教科书在"促进学生...     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Effect of the Method of Modification of Zeolite X on Selectivity of Catalytic Methylation of Toluene

Theoretical and Experimental Chemistry - The effect of the method of modification of catalysts based on zeolite X by cesium and magnesium cations (ion exchange and impregnation) on the selectivity...