小组合作学习在“化学化工专业英语”实践教学活动中存在的问题及解决策略

小组合作学习作为一种主动学习模式被引入到化学化工专业英语课程教学活动中,在具体教学实践中往往存在诸如分组随意、参与度低、分工不明确、缺乏有效评价、流于形式等诸多问题。对采用小组合作学习的班级进行问卷调查并分析统计结果,在此基础上提出合理分组、细致分工、适当指导、及时评价等解决方案,以期对小组合作学习实践教学活动提供相应的理论依据和实践基础。     

小组学习在日常化学教学中有效实施的策略

小组学习是培养学生合作能力和团队精神的重要途径。本文总结了在日常化学教学中组织学生进行小组学习的经验,提出有效实现小组学习的策略是设计主动建构型任务和改变评价方式。并以两个化学教学实例说明了主动建构型任务的特点以及实施的效果,设计了将个人评价和小组评价进行对立统一的定量组合的评价方式。     

高中生化学调查探究能力的现状与发展策略研究

化学调查探究能力是化学新课标要求的3种科学探究能力之一。分析了高中生该能力的现状及形成原因,阐述了发展的指导策略,即结合教材、联系实际、立足学生、小组合作、引导督促、多元评价相结合。     

有效组织讨论进行化学理论课教学的策略研究

讨论是一种好的合作学习方式,化学基础理论是中学化学教学的重点也是难点,将讨论这种方式引入理论课教学是非常必要的,如何在化学理论课教学中有效组织讨论是一个重要课题,目前此方面尚无人研究。本文分别从讨论内容的组织策略、讨论的开展策略、学生的组织策略、讨论形式的组织策略、评价策略5个方面,提出在化学理论课上讨论式教学的多种有效组织策略。在课堂讨论中只有将教师、学生、问题这三要素有机地结合到上述5个方面的具体策略中,才能使课堂讨论真正有效地进行。在此过程中教师是主导,学生是主体,问题是主线。     

化学合作学习的教学设计研究

合作学习以组内异质、组间同质为合作学习小组的基本组织形式,系统利用教学中诸动态因素之间的互动,促进学生的学习,以计个人和团体成绩为评价标准,从而共同完成教学的目标.本文结合合作学习的内涵和理论研讨了合作学习的意义,并提出了中学化学教学中的5种化学合作学习方式.     

通过课堂观察法比较中等生和优等生的化学课堂学习行为——以"弱电解质的电离"为例

课堂是学生学习的主要场所,本研究通过观察一节化学常态课,对比分析中等生和优等生的化学课堂学习行为.研究发现:学生在化学课堂上体现的主体性不明显,课堂活动以教师为主;优等生在化学课堂表现出学习的投入程度、专注度都比中等生要高;中等生已有的认知结构、元认知策略的不足以及畏难情绪大大影响了他们课堂的有效学习;小组合作学习能大...     

基于学科理解的学习任务设计策略

基于学科理解的学习任务是精细化教学研究的切入点,是核心素养的落脚点.基于分析学习任务的内容、方法、情境要素,结合原电池教学案例,提出以下设计策略:对教学内容本原性、结构化地理解;分析学生认知基础和学习困难,确定学习任务着力点;任务以本原问题体现,显化认识视角;注重学习任务的教学逻辑;活动指向学生的素养发展;创造真实适切...     

化学教学中实施小组合作学习的问题与对策

当前,化学教学中采用“小组合作学习”的方式虽多,但实施效果却不够理想,存在着不少问题,需要正确认识小组合作学习的内涵,提高小组合作学习的针对性和实效性,要注重面向全体学生组建小组、设计内容、展示学习成果,要充分发挥教师的主导作用。     

关于学法指导的理性思考：怎样在化学教学中指导学生学会学习

本文是对化学教学中学习方法指导所进行的理性思考。认为充分发挥主体性是学法指导的着眼点,引导学生学会学习是学法指导的关键,教 会学生掌握运用科学的学习模式是学法指导的基本策略促使学生总结评价自身学习状况是对学法指导的升华。     

基于学生自主、合作学习过程的元素化合物课型教学实践——以“铁盐和亚铁盐的性质”为例

在“国培计划”高中化学观摩课“铁盐和亚铁盐的性质”的教学设计和教学实践中,通过向学生提供具有一定开放性和综合性的学习任务,学生在自主、合作学习过程中对元素化合物性质的学习内容产生深度思考,并对学习过程产生深度体验。教学结束后,通过问卷调查学生对自主、合作学习过程的自我评价,对元素化合物课型中促进学生自主、合作学习能力发展的教学理念和教学方法进行讨论。     

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。