共查询到20条相似文献,搜索用时 952 毫秒
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化学实验探究中, 论证教学以学生对氢氧化钠潮解现象的不一致解释为契机, 然后通过实验收集证据, 以证据、推理和结论3个要素为框架做出论证, 最后修改与评价论证, 有目的地将论证融入到探究活动中。 相似文献
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以Chrysi和Douglas提出的论证图为基本范式,对其进行优化,并提炼出论证图的4大基本要素,即中心议题、支持性证据、反对性证据和层次等级,论述了论证图促进初学者学习科学论证的工具性作用:为科学论证搭建脚手架,使论证过程可视化和有利于学生论证能力的评估。提出了基于论证图进行科学论证的4个步骤:中心议题的选择、证据的搜集、层次等级的绘制和科学论证的展开,并以"原电池"的教学设计为例进行说明。 相似文献
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基于SOLO分类理论,构建论证评价标准,以"全球变暖"作为议题,调查了广州市某中学初三至高三年级共327名学生的科学论证能力。结果表明,中学生论证能力的整体水平不高,处于单一结构与多元结构水平之间。各论证要素的得分从高到低为:证据 > 理由 > 主张 > 反证,其中证据和理由的得分均显著高于主张和反证的得分。各年级男女学生在所有论证要素的得分中没有显著性差异。证据得分,高三 > 高二 > 高一;理由得分,高三、高二>初三;主张和反证得分4个年级没有显著性差异。本研究的创新之处是将SOLO分类理论应用于科学论证评价,突破了以往论证评价框架中,仅依据论证要素是否具备及数量来评价的视角,从而深入到论证要素之间关系的考察。 相似文献
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在职前教师教育类课程"化学实验教学论"中,以喷泉相关实验为例,设计论证问题和评价细则,开展论证教学的实践和探索。研究细致分析并揭示了职前教师在论证建构中存在的理由不充分,逻辑推理欠严密;忽略前提条件或特定背景;多采用直觉启发式,少采用系统分析式等问题。这为提高职前教师科学论证能力提供了参考。 相似文献
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在界定了化学实验呈现方式的含义的基础上,从5个方面对化学实验呈现方式的类型进行了划分,并指出化学实验的呈现方式具有多种功能。 相似文献
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V. I. Bol'shakova L. I. Demenkova É. N. Shmidt V. A. Pentegova 《Chemistry of Natural Compounds》1989,24(6):691-694
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. 相似文献
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利用手持技术改进测定乙醇分子结构实验 总被引:1,自引:0,他引:1
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。 相似文献
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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。 相似文献
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Effect of the Method of Modification of Zeolite X on Selectivity of Catalytic Methylation of Toluene
Voloshyna Yu. G. Pertko O. P. Patrylak L. K. 《Theoretical and Experimental Chemistry》2019,54(6):395-400
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... 相似文献
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Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin
E. I. Kapinus V. A. Ganzha B. M. Dzhagarov E. I. Sagun V. B. Pavlenko 《Theoretical and Experimental Chemistry》1989,25(2):146-151
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. 相似文献
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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. 相似文献
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Kopranenkov V. N. Makarova E. A. Dashkevich S. N. Luk'yanets E. A. 《Chemistry of Heterocyclic Compounds》1982,18(11):1218-1218
Chemistry of Heterocyclic Compounds - 相似文献