“测定空气中氧气体积分数”实验再改进

“测定空气中氧气体积分数” 的实验是现行各版本5义务教育课程标准实验教科书：化学6 （九年级上册） 中的一个重要实验。笔者针对教材中实验装置的不足[1] ,在前人研究[2~4] 的基础上,设计了一种易于学生理解实验原理的装置。     

简便、准确测定空气中含氧量的方法

空气中氧气体积分数的测定是义务教育阶段一个重要的化学实验.传统实验是用红磷的燃烧来测定,实验安全性和准确性不高,不能满足实验教学之所需.前人对此已经有很多改进研究[1,2],但不能让学生直观地观察到空气中氧气的体积分数为21%.笔者对该实验重新设计,改用白磷在注射器内燃烧来测定,使实验达到满意的效果.     

由一"斑"窥全貌--从初中化学教材变化看课程改革

2002年我们宜昌市成为全国课程改革实验区之一,笔者有机会接触到3种版本的初中化学教材：人民教育出版社九年义务教育三年制初级中学教科书《化学》(全一册)[下称“人教版教材”];人民教育出版社义务教育课程标准实验教科书《化学》(上、下册)[下称“人教版实验教材”];上海教育出版社义务教育课程标准实验教科书《化学》(上、下册)[下称“上教版实验教材”]。在教学教研的工作实践中笔者依据中华人民共和国教育部制订的《全日制义务教育化学课程标准(实验稿)》[下称“化学课标”]的精神对这3种版本教材的主要栏目设置及内容作了如下的统计分析：     

实验配置不可忽视的课改条件--关于初中化学实验教学现状的调查分析

2002年秋期,德阳市部分市、区的初中、小学起始年级开始基础课程改革,并按照义务教育课程标准实施各科教学。到2004年秋期,在初中的这一部分学生,就将按照《全日制义务教育化学课程标准(实验稿)》(以下简称《化学课标》)要求学习化学。为了掌握初中化学实验教学的现状,做好《化学课标》实施前的一切准备工作,笔者对旌阳区参加课改的各中学初中化学实验教学现状进行了调查研究。     

中考化学实验试题与课程标准一致性的比较分析

基于“SEC”一致性分析模式,对福州、厦门、泉州的中考化学实验试题与《义务教育化学课程标准（2011年版）》中实验内容主题和认知水平要求进行一致性编码分析,总结实验题的命题特点,提出实验教学应有所侧重,命制实验题应紧扣课程标准要求。     

对沪教版初中化学教材中新增实验题的商榷

上海教育出版社2009年11月出版的《义务教育课程标准实验教科书:化学》第176页新增第8题是一道实验习题,研究物质在水、汽油中的溶解性,旨在说明同种溶质在不同溶剂里的溶解性不同。笔者发现,此题实验2中描述的实验现象和给出的实验结论值得商榷。     

中学化学教科书中实验安全教育内容编排的思考

随着课程改革对化学探究实验的重视,实验安全教育的重要性日益显现。通过对我国现行3个版本义务教育初中化学课程标准实验教科书及美国初中主流化学教科书《化学反应》中的化学实验安全教育内容的比较研究,发现我国教科书中实验安全教育内容相对薄弱。建议以教科书为载体显化实验安全教育内容、教科书中增加实验安全标志、处理好安全教育与主动探究的关系,把安全作为实验评价指标,充分发挥评价的导向功能。     

《盲校义务教育化学课程标准》解读

在《全日制盲校义务教育课程设置实验方案》核心思想的指导下,将之与普通学校《义务教育化学课程标准(2011年版)》对比分析,结合盲校教育对象及其教学特点,解读《盲校义务教育化学课程标准(2016年版)》的理论基础、研制原则和修订内容等。     

初中化学教材中"酸雨模拟"探究实验的改进

现行上海教育出版社<义务教育课程标准实验教科书:化学(下册)>第244页安排了"酸雨模拟"探究实验,以帮助学生通过实验去认识酸雨的成因,同时增强学生的环保意识.     

《义务教育课程标准实验教科书·化学》分析

本文在研究《全日制义务教育化学课程标准(实验稿)》(以下简称《课程标准》)的基础上,对中学化学国家课程标准研制组编写的《义务教育课程标准实验教科书·化学》(九年级上册、下册)(以下简称《标准组化学》)的体系结构、体例与栏目、特点与启示等进行了分析,并对教科书的编写和修订提出了建议。《标准组化学》从学生的发展需要构建教科书内容体系,体现化学与科技进步和社会发展的关系,贴近学生的生活实际,加强科学探究活动,提倡多样化的学习方式。这些新的尝试体现了化学课程改革的新理念,反映了《课程标准》的精神和要求,有利于培养学生的创新意识和实践能力,全面地提高学生的科学素养。     

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。     

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.     

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.     

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。     

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。