“显性”科学本质教学与论证结合对学生科学本质观影响的研究综述*

科学教育文献建议运用“显性”教学提高学生对科学本质的理解,但其有效性仍有待加强。近年来,论证领域的新兴研究表明,学生参与论证对提高他们的科学本质观具有积极的促进作用。为了更好地提高学生的科学本质观,在梳理国际科学本质教育文献的基础上,探讨了“显性”科学本质教学与论证相结合的教学方法的研究脉络、研究方法及影响教学效果的因素。以期为教师进行有效的科学本质教学提供参考和建议,并对未来有关科学本质的有效教学的研究提供基础。     

发展学生化学学科核心素养离不开化学实验

化学实验是化学教学的重要组成部分,不仅具有教育教学功能,而且具有发展学生化学学科核心素养的功能。从认识层面、实践层面和价值追求层面来看,化学实验在发展学生科学本质观、科学实践观和科学价值观方面均发挥着不可替代的功能。教师可以利用化学实验史实呈现真实的科学发现过程,发展学生的科学本质观;可以通过引导学生对化学实验现象的观察和基于实验事实证据的推理发展学生“宏观辨识与微观探析”“证据推理和模型认知”素养;可以通过开展化学实验探究,引导学生拓宽认识视角和认识思路,发展学生“科学探究与创新意识”素养;可以通过化学实验评价发展学生的“科学态度和社会责任”素养。     

不同科学史设计对高一学生科学本质观发展的影响——以原子结构发现史为例

科学史是促进学生科学本质观发展的重要策略。本研究以181名高一学生为研究对象,采用准实验设计,探讨了在原子结构教学中,不同科学史设计对学生科学本质观发展的影响。结果表明：无论何种教学设计对学生科学本质观发展都有影响,但影响的方面和程度不同;采用“认识型”、“反思型”的科学史设计效果要明显优于“知识型”。     

模型本质观进阶框架的理论构建及实证研究

在科学学习中,模型本质观是科学素养的关键组成。本研究基于对已有“模型本质观”研究的分析,建构了“模型本质观”的进阶框架,并对初、高中及大学共计381名学生进行调查。研究表明：学生普遍存在对模型本质认识的迷思概念,在“模型和实物间的关系”维度尤为突出。     

中英化学教材“化学反应速率”内容比较研究

“化学反应速率”综合体现了微粒观、实验观及科学本质观等化学基本观念,是提高学生科学素养的重要载体。从内容选取、内容编排与内容呈现3个方面对英国索尔特高级化学课程教材与国内化学教材中“化学反应速率”相关内容的编写进行比较,并简要阐述几点对化学教材编写和化学教学的启示。     

开启新一代的科学教育——美国《K-12年级科学教育框架》述评

美国国家研究理事会于2011年7月发布了《K-12年级科学教育框架》,为开启美国新一代的科学教育奠定基础。《框架》采用“核心学科概念”“交叉观念”和“科学与工程实践”3大维度来建构其结构,将“工程与技术、科学应用”纳入核心学科领域,突出科学的实践本质,并通过“学习进程”来描述科学学习的发展过程。通过对《框架》的解读,开拓我国科学教育改革的视野。     

“显性反思性”的科学本质教学*——以“原子结构”发展史为例

科学本质作为国际科学教育的重要目标,受到越来越多的关注。但在实践中,教师缺少对科学本质的内涵和具体方面的深度理解,同时缺少有效的科学本质教学的相关指导。本文探讨了基础教育阶段科学本质的8个方面的具体内涵,阐明了科学本质的有效教学的特征,并以“原子结构”为例,为教师开展科学本质教学提供范例。     

基于核心素养的HPS教学实践——以“甲烷”为例

基于化学核心素养,以“打开第二自然界的大门”开启甲烷的科学探究与体验之旅,在“历史线”“活动线”“知识线”等3条认知与体验路线中,经历科学概念的形成过程,实现对“稻草变黄金”科学本质的理解,有效地将HPS教育与化学核心素养结合起来,使学生体会化学发展的过程与方法,感受化学的学科魅力和发展成就,以提高学生的学习兴趣。     

基于研究性学习的高校“化学史”课程改革与实践

基于研究性学习的理念,以化学专业本科生专业拓展课程“化学史”为研究对象,通过教师专题讲座、学生课堂演讲和课堂剧演出等形式进行了课程改革。实践结果表明,在检索化学史和化学各学科相关文献、确立话题、编制演讲稿或演出剧本、排练并进行演讲或演出的过程中,学生较好地体验了学科知识主动内化的过程,掌握了研究性学习的方法,培养了语言表达能力和团队协作能力,陶冶了科学情操并体会了科学品质和科学精神,有效提高了“化学史”课堂的学习兴趣和主动性。     

科学实验教学中启发式科学写作(SWH)工具的发展及应用*

为提高科学写作在实验教学中培养学生能力的目的,韩德(Brain Hand)等人开发了一种实验教学的科学写作工具--启发式科学写作(SWH),是一种建立在科学语言与课堂探究基础上的论证工具,通过“问题、方法、观察、观点、证据、评判、转变”的过程使得科学内容与语言活动联系起来,激发学生参与论证,从而促进学生对科学的理解。SWH在实验教学中的具体应用还受到多种因素的综合影响。SWH从“框架建构到具体实施”、从“理论到实践”的研究思路对其他教学或学习工具的研制具有启示性意义。     

Investigation of the sorption of water vapor on cation-substituted vermiculite. 2. Thermodynamic description of sorption equilibria

The changes in the thermodynamic functions of the sorbents were calculated for the first time from measurements of the deformations of vermiculite during the sorption of water vapor and adsorption-calorimetric data.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Institute of Colloid Chemistry and the Chemistry of Water, Academy of Sciences of the Ukraine, 252180 Kiev. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1270–1275, June, 1992.     

Thermodynamics of ionization of water over wide ranges of temperature and pressure

We have summarized results of many experimental investigations of the thermodynamics of ionization of H₂O(liq.) from 0–300°C and from 1.0 atm to nearly 8000 atm. Results of these investigations (equilibrium constants, enthalpies of ionization, heat capacities, partial molal volumes, and compressibilities) have been used for a number of thermodynamic calculations. It is particularly noteworthy that it is possible to use thermal data from 0–145°C with an equilibrium constant for 25°C in calculating reasonably accurate equilibrium constants for temperatures as high as 300°C. Similarly, it is possible to use volumetric data that refer to 1.0 atm in calculating useful equilibrium constants that apply for pressures as high as 2000 atm.Much of the work reported here was done while the author was on leave at the University of Lethbridge.     

Thermochemistry of aqueous solutions of alkylated nucleic acid bases. VIII. Enthalpies of hydration of 6-alkyluracils

Enthalpies of solution in water H _sol ^o and enthalpies of sublimation H _sub ^o were determined for a number of crystalline derivatives of uracil: 1,6-dimethyluracil (m ₂ ^1,6 Ura), 1,3,6-trimethyluracil (m ₃ ^1,3,6 Ura), 6-ethyl-1,3-dimethyluracil (e⁶m ₂ ^1,3 Ura), 6-propyl-1,3-dimethyluracil (pr⁶m ₂ ^1,3 Ura) and 6-butyl-1,3-dimethyluracil (but⁶m ₂ ^1,3 Ura). Standard enthalpies of hydration H _hydr ^o and standard enthalpies of interaction H _int ^o of the solutes with their hydration shells were calculated. The data obtained show that dependence of H _int ^o on the number of-CH₂- groups of n-alkyl chain added upon substitution of diketopyrimidine ring is nonlinear. This finding is discussed in connection with results of X-ray diffraction structure determinations for the crystalline compounds.     

计量数比规则与等物质的量规则的比较

指出了计量数比规则存在的缺陷:不利于贯彻有关物质的量及其单位摩尔的SI规定,不能继承当量定律的数据资料,不能表示反应的性质,不能正确表达水硬度、碱度、树脂交换容量及电解定律,缺乏科学的导出过程及计量关系表达式,计算过程繁杂。而等物质的量规则继承和发展了当量定律,使整个滴定分析计算简单规范。     

从科学哲学的视角分析科学课堂教学——以“质量守恒定律”为例

以“质量守恒定律”为例,选取科学革命、科学问题、科学实验、归纳与重复、解释与预测等几个视角对科学课堂教学的各个环节进行了分析。通过分析,各环节中所蕴含的科学哲学内容得以显现,对科学课堂教学的认识更为全面,对科学本质的认识更加深刻。     

Thermodynamics of lonization of aqueous lodic acid,an “almost-strong” electrolyte

We have made calorimetric measurements of enthalpies of dilution of aqueous iodic acid and have used these results for evaluation of the standard enthalpy of ionization of HIO₃(aq.). We have also made calorimetric measurements of enthalpies of addition of perchloric acid solution to aqueous solutions of KIO₃, KNO₃, NaIO₃, and NaNO₃ and have used these results to obtain further values for the standard enthalpy of ionization of HIO₃(aq.). On the basis of all these results, we have selected H^o=–660±125 cal-mole^–1 as the best available standard enthalpy of ionization of HIO₃(aq.) at 298.15°K, compared to the previously accepted –2400 cal-mole^–1. Using the best available K=0.157 for ionization, we also obtain G^o=1097 cal-mole^–1 and S^o=–5.9 cal-^oK^–1-mole^–1 for ionization of HIO₃(aq) at 298.15°K.On study leave from Department of Inorganic and Analytical Chemistry, LaTrobe University, Bundoora, Victoria, 3083, Australia, to University of Lethbridge.On study leave from Department of Chemistry, University of Wollongong, Wollongong, N.S.W. 2500, Australia, to University of Lethbridge.     

对离子反应发生条件中“放出气体”的再认识

离子反应发生条件中的“放出气体”,与其他资料中对生成物的描述不一致,也与有关反应事实不符。“放出气体”的出现,使教材中对气体生成物的描述时此时彼,没有时序性、规律性。对其与化学反应的关系及其与“生成气体”的区别进行了论述,并提出了修改的建议。     

Thermodynamics of vaporization of gallium trichloride

The unsaturated and saturated pressures of gallium trichloride vapor were measured by the static method with membrane-gauge manometers in wide pressure (0.2–760 Torr) and temperature (313–1071 K) intervals. Scanning calorimetry was used to determine the thermodynamic characteristics of GaCl₃ fusion. The thermodynamic characteristics were obtained for sublimation, fusion, vaporization, and association in the vapor of GaCl₃ molecules. The enthalpies of formation and the absolute entropies of GaCl₃ in the liquid and gaseous phases and Ga₂Cl₆ in the gaseous phase were calculated using literature data. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1266–1269, July, 2007.     

Thermochemistry of aqueous solutions of alkylated nucleic acid bases V. Enthalpies of hydration of N-methylated adenines

Enthalpies of solution in water, H _sol ^o , and of sublimation, H _subl ^o , were determined experimentally for a number of crystalline N-methyl adenines: m⁶Ade, m ₂ ^6,6 Ade, m⁹Ade, m ₂ ^6,9 Ade, and m ₃ ^6,6,9 Ade. Derived standard enthalpies of hydration H _hydr ^o , were corrected for the calculated cavity terms H _cav ^o to yield enthalpies of interaction H _int ^o of the solutes with their hydration shells. The increments of H _int ^o per unit area of the water-accessible molecular surface S _B , H _int ^o (CH₃)/S _B (CH₃), for the particular methyl groups: is considered to be the net effect of the gain in the energy resulting from van der Waals' interactions and of the loss in the energy due to polar interactions upon methyl substitution. It proved to vary somewhat numerically in agreement with the theoretically predicted hydration schemes of adenine. Comparison of H _int ^o /S _B value for adenine with those previously determined for uracil and thymine indicates that the aminopurine moiety is less hydrated than the diketopyrimidine ring.     

Effect of specific adsorption of anions on the kinetics of the current relaxation after pulsed anodic activation of dissolution of hydrophilic metals

Based on the model of spatial separation of the dissolution and passivation of hydrophilic metals, the effect of strong specific adsorption of anions on the shape of curves for the relaxation of anodic current of metals in acid solutions after switching an anodic activation pulse off is considered by using iron as an example.