共查询到20条相似文献,搜索用时 110 毫秒
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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。 相似文献
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以乙酸乙酯制备方法改进为目标,通过“分析直接酯化法的缺点,设计新合成方法” “探索改进实验方案” “总结汇报,分析实验方案的适用情境”等3个任务,使学生加深理解有机化学基本反应类型和认识工业生产的适用条件,理解有机化学与生产实际之间的联系,在探究过程中培养学生的信息处理能力、科学探究精神以及“科学态度与社会责任”的化学学科核心素养。 相似文献
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引导学生从“听化学”向“做化学”转变,从“记化学”向“探究化学”转变。学生只有通过“做化学”“探究化学”,在“做科学”的探究实践中培养创新精神和实践能力,科学素养才有可能得到主动地发展。 相似文献
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采用“中学化学课堂环境问卷”作为研究工具,对深圳市、长春市、佳木斯市等3个地区的4所高中861名学生的化学课堂环境进行调查,并进行差异分析。研究结果表明,高中生对化学课堂环境的总体感知较好,7个维度中“学生凝聚力”“平等”“任务取向”“合作”等4个维度的平均分大于3.4,“教师支持”和“参与”维度的平均分在3.0~3.4,只有“探究”维度的平均分小于3.0。城市高中生对课堂环境的感知明显好于乡镇高中生,学生心目中所期待的化学课堂比实际的化学课堂更积极。 相似文献
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指出了高中阶段“配合物”教学中存在的问题,并从“应用杂化轨道理论解决配合物中心部分的空轨道问题”“尝试判断配位原子”“用平衡思想理解配合物的内界组成”等3个方面阐述了如何在化学学科核心素养的指导下引导学生更好地进行配合物知识的学习。 相似文献
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本文研究了三种可溶性聚酰亚胺(PI)在机溶剂和水溶液中的电化学行为,发现PI在有机溶剂中的电化学行为明显不同于水溶液,利用红外光谱技术才半经验发子轨道计算方法,结合电化学测试的结果,确证了PI的电化学反应的机理。 相似文献
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David Briers Lieven De Cremer Guy Koeckelberghs Stijn Foerier Thierry Verbiest Celest Samyn 《Macromolecular rapid communications》2007,28(8):942-947
A new chromophore, C1 , based on a similar DπA‐structure as in the FTC ‐chromophore but with a hydroxyalkyl spacer perpendicular to the direction of the dipole moment was synthesized. Both chromophores and the CLD ‐chromophore were used to prepare high Tg nonlinear optical vinyl polymers. The influence of the position of the spacer on the DπA‐system on the NLO response of the resulting polymers was investigated.
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Neese F 《Journal of computational chemistry》2003,24(14):1740-1747
A straightforward modification of the resolution of the identity (RI) approximation to the Coulomb interaction is described. In the limit of basis sets that are dominated by high angular momentum functions the observed speedups in realistic test systems reach a factor of 2 compared to the standard RI algorithm, and a factor of up to 300 compared to the standard algorithm to form the Coulomb matrix. More moderate savings on the order of 0-20% are obtained for the more commonly used smaller basis sets. A series of test calculations is reported to illustrate the efficiency of the algorithm. 相似文献
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The chemical compositions of the initial bark of the Siberian firAbies sibirica and of the solid residues after extraction with carbon dioxide, water, and alcohol have been studied. On successive extraction, the yield of extractive substances amounted to 25.05% of the absolutely dry bark. The carbon dioxide, aqueous, and alcoholic extracts obtained have been investigated. The carbon dioxide extract was found to contain 34.97% of essential oil, while only traces of it were detected in the aqueous and alcoholic extracts.Krasnoyarsk State Technological Academy. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 42–45, January–February, 1996. Original article submitted August 14, 1995. 相似文献
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The photooxidation of chloral was studied by infrared spectroscopy under steady-state conditions with irradiation of a blackblue fluorescent lamp (300 nm < λ < 400 nm, λmax = 360 nm) at 296 ± 2 K. The products were hydrogen chloride, carbon monoxide, carbon dioxide, and phosgen. The kinetic results reveal that the reaction proceeds via chain reaction of the Cl atom: The results lead to the conclusion that mechanism (B) is confirmed to be more likely than mechanism (A), which was favored at one time by Heicklen for the mechanism of the oxidation of trichloromethyl radicals by oxygen molecules: The ratio of the initial rates of CO and CO2 formation gave k7/k6 = 4.23M?1, and the lower limit of reaction (5) was found to be 3.7 × 108M?1 sec?1. 相似文献