化学学习中"宏观-微观-符号"三重表征的研究

“宏观-微观-符号”三重表征是体现化学学科特征的思维方式,能增进学生对化学知识的理解。本研究在对三重表征思维方式进行分析的基础上,采用问卷调查的方法,对不同群体学生化学学习三重表征水平进行了探查和分析,为化学教学提供了一个新的视角。     

促进“深度学习”的教学设计

新课程教学实践中学习方式变革的表面化、课堂师生对话的肤浅化以及三维教学目标的虚化等问题造成了一定程度的浅层学习。深度学习是一种主动的、批判性的学习方式,不仅强调学习者积极主动的学习状态、知识整合和意义联接的学习内容、举一反三的学习方法,还强调学生高阶思维和复杂问题解决能力的提升,为解决浅层学习弊端提供了可行路径。深度学习教学设计需从目标定位、内容选择、策略运用、技术支持以及学习评价等方面进行系统设计。     

突出“宏-微-符”化学思维方式的课堂教学——以“化学式”一节课为例

从宏观、微观和符号3种水平上认识和理解化学知识,并建立3者之间的内在联系,是化学学习特有的思维方式。化学教学必须以培养学生的思维方式,建构化学基本观念为重要目标。本文对"化学式"一节课的教学实录,从"宏-微-符"三结合的角度进行了评析。     

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。     

基于深度学习的有机合成复习课教学实践*——常见高分子材料的用途与合成

基于深度学习理念,以“常见高分子材料的用途与合成”为学习主题,开展关于有机合成复习课的教学实践。指出在有机合成的复习课,开展深度学习有利于激发学生的学习需求、调动学生高阶思维、让学生迁移运用所学知识。基于深度学习的教学设计需要把握挑战性学习主题、深度学习目标、深度学习活动和持续性评价4大要素。提出课前应引导学生开展挑战性学习主题的项目调研;课上应创设引导学生深度学习的问题情境,促进学生高阶思维的发展;课后应让学生以思维导图的形式理顺有机合成的一般方法等,为教师开展基于深度学习的教学实践提供参考。     

基于证据的推理:内涵、意义及培养路径

基于证据的推理，是在掌握证据的基础上推理出新的知识和原理。基于证据的推理对于科学发展、学生的学习及其发展具有重要意义。教学中培养学生基于证据推理的思维方式的途径有：唤醒证据为本的本能，萌发收集证据的意识；学会科学推理的技巧，自发进行合情的推理；分享证据推理的成果，体验证据推理的快乐等。     

Training of Creative Thinking for Undergraduates in Teaching of Polymer Chemistry

根据素质教育与创新能力培养的目标要求，围绕提高学生的学习兴趣和培养学生分析问题、解决问题的能力，激发创造性思维，结合《高分子化学》课程的特点，在教学内容和教学方式上进行了设计。从理论与实际相结合、利用教学模型培养研究性思维、形象化教学、注重分析问题和归纳推理、注重实践教学等方面来探索培养学生创新思维的有效教学方法，并结合笔者自身的教学体会，分析和阐明了这些教学方法在培养学生创新思维中所起的作用。     

化学系统性思维的表征手段与改革实践*

化学系统性思维强调化学子系统之间,以及化学系统与其他学科系统之间的关系,有助于学习者整合、应用化学知识解释化学现象、解决化学问题。内外交织的多个不同系统很容易让学生迷失在纷繁复杂的概念体系中,需要借助SOCME,OPM,BOTG,CLD,SFD等可视化图形工具厘清各个系统之间的关系,以表征化学系统性思维。在明确化学系统性思维内涵的基础上,开展“化学平衡”教学改革,探索绿色化学课程建设,开展游戏化学习、服务性学习、深度学习、项目学习、工作坊或研讨会,有助于化学系统性思维培养实践的改革与落地。横向关联化学系统与其他学科系统的关系,纵向深入分析化学子系统之间的关系,是进一步开展化学系统性思维教学的关键。这就需要多学科的协同攻关,既要关注化学知识的社会应用,也要抓住化学学科本质和特征,才可以围绕化学概念和社会问题,建构纵横交织的多系统影响关系,促进学生化学系统性思维的发展。     

基于辩证思维的学习情境分析模型及应用

辩证思维是对事物的内在矛盾、变化及相互联系进行考察，它是正确认识化学的关键。教师利用情境素材创设合理的学习情境，应引导学生在情境中学习，并树立正确的科学态度。从人文考量、机理解读、理性反思等3个方面构建了基于辩证思维的学习情境分析模型，并以“氯气”“氨”的教学为例，为教师的情境教学提供参考。     

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。     

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。     

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。     

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.     

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.     

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。     

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.     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。