在化学教学中让学生多角度理解化学反应

介绍了中学化学教学中,从物质用途、物质结构、化学实验、物质转化、工业生产等10个不同的角度研究化学反应的一些做法和体会,有利于帮助学生全面地理解化学反应。     

物质结构教学中虚拟与实体模型的比较研究

本文研究比较虚拟与实体模型在中学化学物质结构教学中作用的目的,就是试图帮助学生建构正确的空间图像思维,尝试鼓励和引导学生建构正确的物质结构思维模式,这对于提高学生的思维品质有很大帮助。     

当代中学化学教师智能结构初探

当今世界科学技术突飞猛进,要进行教育体制改革,教育要面向现代化,面向世界,面向未来,这就对我国中学化学教师的智能结构提出了新的要求。作为中学化学教师,教学的主要任务不仅是引导学生掌握物质的组成、结构、性质及其变化规律。     

注重中学化学计算教学方法的点滴体会

化学计算在中学化学中占有重要地位。在化学计算教学的过程中,我们教师应该注意教学方法,把培养学生的能力,发展学生的智力放在首位。培养学生勤观察,勤思维,勤分析的良好习惯,努力提高学生分析、解决实际问题的能力。下面谈谈我在化学计算的教学中,注重教学方法的点滴体会。     

发挥实验优势 加强启蒙教育

初三化学是中学化学的启蒙。几年来,我们在初三化学教学中,对如何发挥实验优势,激发学生的学习兴趣,对如何利用化学实验来启迪学生的思维,开发学生的智力,提高学生的能力等,在教学内容和教学方法上进行了探讨。     

建立“稳定性”概念 培养思维能力

在中学化学的学习内容中,物质的性质及变化占有极其重要的地位。但物质种类多,反应规律多,往往使初学者感到知识零乱,而单纯地记忆;面对高考的学生感到内容多而庞杂。     

香港中学化学科学素质教育的发展

80年代以前,香港的中学化学教育跟世界理科教育的主流一样,强调给学生以系统的学科理论知识,以适应继续升学的需要.教学方法基本上是注入式.     

论课程改革中的初高中化学衔接教学

实施中学化学课程改革,要坚持“为了每一位学生的发展”的基本理念,从知识体系、教学方法、学习策略和情感态度4个方面搞好初、高中化学衔接教学。     

在化学教学中进行实习作业的体会

实习作业是化学课的基本内容也是完成中学化学教学任务的重要手段。在新公布的中学化学教学大纲(修订草案)里,对实习作业在中学化学教学中的意义及它在各个年级里的分配,作了比较明确的说明和具体的规定,这充分说明新的教学大纲对实习作业的重视。正如大纲说明中所指出:“实习作业对于使学生巩固所学到的化学上的重要事实和理论,使学生了解化学生产的科学原理,使他们获得使用物质、鉴别物质的技巧,都是有重大的意义”。实习作业使学生能够直接认识具体的物质和现象,从而对物质的性质和变化的规律有明确的观念;通过亲自进行实验,可以帮助学生养成实际中应用知识的技能,培养实验的技巧和独立的工作能力,而这些对基本生产技术教育有重大的意义。在实习作业中,还能帮助培养学生的自觉纪律以及对劳动和公共财物的社会主义态度。因此作为一个化学教师对实习作业应予以足够的重视,认真贯徹大纲的要求和指示,学会善于组织安排实习作业课,使其能真正达到上述任务。     

综合大学化学系各专业无机化学课程试用

说明无机化学这门课程应该在门捷列夫周期律与近代物质结构概念的基础之上,使学生获得有关化学元素的性质及其相互关系的全面认识。这课程的教学大纲充份地重视元素在自然界中的行为、无机原料的提炼原理以及这些元素及其化合物的实用意义。无机化学的教学应该是建筑在学生已经完全掌握了中学化学教学大纲中的教材之上的,但目前也应该适当地照顾到我国中学化学教学的实际水平。     

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...