结构化学和计算化学有机结合实现“1+1>2”追求理解的学习

针对结构化学和计算化学的课程特点和学生学习两门课时的学情分析,提出了结构化学和计算化学在授课过程中有机结合、相互渗透,实现“1+1>2”的教学效果和追求理解的学习,为学生理解结构化学的抽象概念和理论以及理解计算化学的基础知识提供一种很好的学习方法,也为教师提供一种很好的教学策略。     

理解著文强化记忆——化学研究性学习过程中穿插诗歌教学的尝试

将诗歌引入到化学教学中,增强了学生对化学知识的理解,促使了学生对化学知识的记忆,加强了化学知识与社会、与相关学科的联系,是研究性学习的一种尝试。文中介绍了对在化学学习过程中穿插诗歌教学的理解与做法。     

高分子化学开放性实验开设初探

为了更好的提高学生对理论课知识的学习和掌握,我们结合自身的教学实践,在高分子化学课程开设的同时开设高分子化学实验,并将开放性实验的特点“设计性、综合性”引入到高分子化学实验教学过程中。通过设计性实验使学生成为学习的主体,主动学习,达到对高分子化学理论知识深入理解和掌握;通过增加综合探究性实验,使学生对高分子化学前沿学科...     

在化学新课程中培养学生元认知能力的教学策略研究

元认知理论的提出从更深层次上理解了人类学习的过程。在新课程背景下,结合元认知理论对漳州市高一学生在化学新课程学习中的元认知情况进行问卷调查,针对调查情况,研究提出了在化学新课程中培养学生元认知能力的教学策略。     

运用计算机理论模拟辅助化学教学研究

以取代反应动力学研究、理解防晒品功效和红外光谱与分子构型等教学方案为例,探讨了计算机模拟中不同模块在辅助化学教学方面的应用,这些模块不仅能用于解释化学教学中学生较难理解的生涩概念,而且可以给学生提供亲身实践经历,更好地帮助他们总结数据以及形成自己的结论,激发学生对化学学习的兴趣,提高教学质量。     

用3D MAX制作化学三维结构特技

在运用现代教育技术开展化学多媒体教学的过程中,我们经常要把化学中的一些微观现象放大,多角度、全方位的模拟一些三维结构动画,营造一个愉悦的学习环境,使许多抽象和难以理解的内容变得生动有趣,有效地调动学生的各种感觉器官进行学习,提高学习效率。     

运用科学阅读策略提高中学生的化学学习能力

科学阅读是科学学习的重要组成部分,将科学阅读策略应用于化学学习中,有利于学生对化学概念和化学知识的理解,有利于学生将新知识、新概念整合到自己的认知结构中,从而达到有意义的学习。     

小学科学化学实验教学中的注意分散研究

小学科学中的化学实验是学生获取科学认识的重要方式。经观察研究发现,小学化学实验教学中存在明显的注意分散现象。实验教学过程中的注意分散问题会影响学生科学探究能力的培养,阻碍学生科学知识的获取和科学概念的形成。通过观察小学科学的课堂以及分析小学科学2012-2018年的优质课视频,根据课堂中注意分散的不同现象,划分了注意分散的类型;结合教育目标分类学、认知负荷理论及注意资源限制理论,剖析了小学化学实验教学中注意分散的原因,提出解决小学化学实验教学中注意分散问题的对策。     

高中生“化学守恒”思维水平状况的调查分析

“化学守恒”是化学学科的基本思想之一,学生若在学习过程中具备守恒思想,将能提纲挈领地把握化学规律,更深刻地理解化学本质.结合学生的认知水平对“化学守恒”内涵进行界定,并制定了“高中生‘化学守恒’思维水平考查指标体系”,运用测试和访谈等手段来考查高中生“化学守恒”思维水平状况.结果表明:高中生对“化学守恒”思想的理解处于中等水平,且对“物质守恒”的掌握明显优于对“能量守恒”的掌握.     

基于模型与建模的化学学习过程设计

在阐释模型分类、模型功能和建模学习的意义的基础上,以“浓度对化学反应速率的影响”之学习过程设计为例,说明在化学教学中通过确立建模目标、模型参数选择、模型建构及表征、分析、评价、调用、重构等活动,可有效提升学生心智模型与表达模型的内在一致性和有效性,促进学生对化学知识的有效探究和深度理解。     

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。     

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。     

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。