美国SATⅡ化学考试简介与浅析

SAT是美国高考性质的测试。介绍了SATⅡ化学考试的基本情况、化学试题的特例以及特点,以期给我国的化学高考改革带来一些有益的思考与启发。     

化学学科素质教育与高考命题

本文探讨了化学学科素质教育与高考命题的关系,对今后全面实施素质教育形势下的化学高考命题思路提出了设想。     

化学思想在高考中的体现与对学生复习的启示

化学思想是化学学科的灵魂。化学思想在高考中体现非常明显。通过分析化学思想,可以提高学生对于化学的理解,提高化学高考复习效率。     

以学科基础知识为载体 培养学生综合能力：谈谈高考改革后高三化学复习

高考改革的浪潮向我们迎面扑来,江苏等地的高三毕业生今年试行“3+X”高考。面对高考改革,我们这些中学化学教师,真有“拔剑四顾心茫然”,有力不知何处使的感觉:没有配套教材,没有相应的练习题和具体的实施细则。遇到新问题,还用老方法解决,效果肯定不佳,只有行动起来,投身到改革的浪潮中去,这样才能跟上时代的步伐。高考改革其目的是更好地考查学生的能力,根据这一总的目标和化学学科的特点及原来高三化学复习的方法,现对高三化学复习,谈谈我个人的见解。1　在新形势下,按照学生的认知规律制订复习计划　　要提高高三复习的效率,首先应有…     

江苏省2008年新课标下高考的备考调查及其分析

2008年6月江苏省将进行新高考,这是江苏省自新课程改革及新高考方案颁布后的第一次高考,全社会极为关注。通过调查苏州、南通、盐城的6所学校的高三学生和化学老师,针对化学新教材的使用、新课标的理解、新高考方案的出台及备战新高考的过程中出现的问题进行全面的分析,并提出了相应的建议和对策。     

课程改革背景下高考对化学教学的要求--从3份高考化学试题得到的启示

从2005年上海、江苏、广东三地的化学单科考试试卷分析课程改革背景下的高考化学考试的特点,探讨高考对高中化学教学的导向与指挥作用。     

从化学核心素养角度探查我国高考化学考试

从高中化学核心素养的5个维度出发，参考2017年高考大纲修订内容，对3份高考全国卷化学试题采用对核心素养进行赋分的方式进行统计。统计表明：高考全国卷试题基本涵盖对化学核心素养的考查，大部分试题实现对核心素养的综合考查，“科学态度与社会责任”维度考查的比重过小等。提出我国高中化学考试评价应落实核心素养要求， 5种化学核心素养的考查应保持合理比例等建议。     

"3+X"高考后特区内高中生学习化学情况调查与对策

自广东省实行“3+Ｘ”高考以后 ,高考试卷与考生的学科流向发生了极大的变化 ,给高中的教学与高考备考都带来了新的挑战与新的问题。对中学的化学学科教学 ,也产生了较大的影响。目前大学招生的热门系科一般都需要考物理与政治学科 ,而由于深圳特区内环境保护方面的原因 ,在就业问题上 ,化学方面的人才需求较少。因此 ,报考化学的学生人数较少 ,成绩优秀的学生一般也不选择学习化学。高中化学教师也在抱怨 ,化学考生素质太差 ,高三化学的教学与复习投入大产出少。教师中存在缺乏信心和无所作为的思想。为了清楚地了解高考改革后对学生学习化…     

运用化学视角透视社会热点--高考综合科目(化学)专题复习初探

今年部分省市的高考科目中出现了"综合科目"这一新的科目,综合科目是高考"3+X"改革的又一个重要举措.教育部教学[1999]3号文件中明确指出:"3+X"要突出"3+综合".这意味着"3+综合"将是今后高考改革的大方向,综合科目将是"X"的最终形式.既然如此,加强对综合科目的教学研究是非常必要的.本文罗列了笔者在综合科目(化学)教学中的一些做法,以抛砖引玉.     

2009年加拿大化学竞赛试题评析

加拿大化学竞赛（CCC）倡导将化学和工业、技术、环境相结合,以培养学生学习化学的兴趣为宗旨。由于加拿大没有全国统一的高中毕业考试和招生制度,因此CCC赛事为学生提供了用全国的标准来衡量化学学科的学业水平的平台和机会。CCC试题充分体现了加拿大科学课程的核心理念即“科学素养的培养”,其试题特点,尤其是主观题考查方式对于我国化学竞赛和高考试题改革具有一定的借鉴作用。     

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。