新课程背景下化学科学探究活动的设计和评价

本文研究新课程背景下科学探究活动的设计和评价,探索网络环境下,“空气污染的成因与防治”科学探究活动的实施。通过创设“问题情境、任务驱动、自主探究、解释与结论、协作与交流、反思与评价”六个教学环节实施科学探究活动。并对科学探究活动作过程性、综合性、发展性、多元化的评价,有利于激发学生科学探究的兴趣,培养学生科学探究意识、协作精神、创新精神和实践能力,提高学生信息素养和科学探究能力。     

在科学探究中发展学生元认知能力的培养模式研究

科学探究的自主性特点决定了它在发展学生元认知方面的重要作用。那么,如何在科学探究中发展学生的元认知能力?为了成功的将元认知训练与科学探究活动相结合,本文尝试性的提出了在科学探究中发展学生元认知能力的培养模式,并通过案例进行了解析。     

与科学探究相匹配的化学教学内容选择研究

培养学生的科学探究能力,已经成为当代化学课程与教学改革的核心要求。围绕科学探究进行化学教学内容的选择、创设一个有利于进行科学探究的情景是当前迫切需要解决的问题。本文从增强学生对化学学科内容的理解能力、有助于理解科学家是如何研究自然界的、培养调查能力和科学思维等方面讨论了选择化学教学内容的原则。     

在科学探究中培养学生的元认知能力

科学探究的自主性特点决定了元认知在化学科学探究中的重要作用。本文分析了元认知在科学探究中的渗透并探索性地提出了在科学探究中培养学生元认知能力的策略。     

五年制学前教育专业学生科学探究能力的调查研究

通过调查研究,河北省五年制学前教育专业学生的科学探究能力很低,他们不熟悉完整的科学探究过程,很少亲身经历科学探究过程的各个环节。因此提出:学校应重视自然科学课程,将科学探究能力写入科学课程标准,严格执行课程标准,挑选合适的内容进行探究教学,采用探究教学法进行教学等建议。     

探究教学论析

探究教学是现代西方料学教学理论和实践的重要基础之一。它以培养学生的探究素养和探究精神为主旨,强调科学方法、科学过程和科学观念的教育。突出学习中的学会探究和探究中学会学习。探究教学不仅有丰富的教育观,也有深厚的方法论。这就是探究教学的过程论。教学模式和教学策略。     

关于高一学生化学探究能力的调查及思考--高中化学课程探究性学习的方法和途径研究课题初报

探究学习作为一种重要的学习方式,对培养和发展学生的科学素养有不可替代的作用,如何评估学生的探究能力?目前学生的探究能力的现状怎样?本研究采用问卷调查的方式对上述问题做了初步探究。结果表明：(1)提出问题并形成课题的能力、猜想与假设的能力、制定探究方案的能力、收集证据的能力、分析证据并形成结论的能力、评价与反思的能力、合作与交流的能力是构成科学探究能力必不可少的要素。(2)高一学生化学探究能力普遍偏低,探究能力各要素发展不平衡。     

对3套高中化学必修模块教材中科学探究栏目的思考

通过对“人教版”、“鲁科版”及“苏教版”高中化学必修模块教材中科学探究栏目进行统计后发现,3个版本教材所设计的探究活动都以实验的、局部的、学生个体的探究为主;要求学生完成的探究要素以“进行实验、收集证据”较多,对“提出问题、猜想与假设、制定计划”的要求较少。笔者认为,教师在教学过程中应注意培养学生的问题意识,提高提问的技能;鼓励学生大胆猜想,科学制定计划;促进学生反思与合作学习。     

量表法评价中学生化学科学探究能力

运用“基本要素分析法”对学生科学探究活动及能力进行要素分析,结合学生科学探究活动的实际特点,制定了科学探究能力的评价量表,为评价学生科学探究能力提供一个参照标准。     

化学教学中培养学生决策能力的一般过程及方法研究

基础教育课程改革的核心理念是为了每一位学生的全面发展,而人的全面发展离不开决策能力的提高,它是学生在知识与技能、过程与方法、情感态度与价值观等3个方面得到发展的集中体现。因此,培养学生的决策能力已成为化学教学的重要目标。本文着重阐述了决策能力的内涵、培养学生决策能力的一般过程和方法,文中谈到的决策指的是科学的决策。     

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.     

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。     

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.

     

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。     

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.