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以“探秘铁肥的合理使用”为主题,开展高中化学“铁及其化合物”的项目式教学。通过完成“确定铁肥的主要成分”“检验铁肥是否变质”“铁肥的合理使用”等3个任务,学生学会不同价态铁元素化合物的转化和检验方法,形成从元素价态和物质类别角度探究物质性质的思路。初步培养了实验探究能力,提升创新意识,发展基于“铁及其化合物价类二维模型建构”的模型认知素养。学生收获了真实新颖、亲身实践、分组合作、交流展示等成就性体验,制作的铁肥保存和合理使用说明书体现了项目式教学的本质特征,实现学习结果的可视性、共享性、交流性。 相似文献
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设计了“铁盐和亚铁盐”的单元教学,以“探究硫酸亚铁的性质”和“线路板腐蚀液的研究”为核心任务,把铁盐与亚铁盐的性质、Fe2+和Fe3+的相互转化等核心知识贯穿其中,建立从物质类别、元素价态视角研究物质性质及转化的思路方法,促进多维度化学学科核心素养的融合发展。经过多轮次教学改进,结合教学实践过程及其教学效果抽提出“注重应用无机物的认识模型,重点把握研究物质性质的角度和思路”“抓住典型活动,培养学生的关键能力”“设计开放性任务,通过有效的师生对话进行诊断,外显问题解决思路”等教学策略。 相似文献
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逆向教学设计被称为“通过设计促进理解”的教学设计。教学过程中,教师结合课程标准相关要求进行单元逆向教学设计,有助于学生提升学科核心素养,引发深度学习。围绕“钠及其化合物”开展了逆向设计的相关探索。根据逆向设计模板,同时,结合本单元学生需要获取的目标、知识和表现性任务,设计了4个课时的教学任务。单元教学过程整体实现了初始培养学生从微观结构出发,结合实验事实认识钠的性质,进而到学生分析物质性质的相似性和差异性,然后到学生结合相关资料实现鉴别实验方案的设计,最终学生结合相关资料进行纯碱制备工业应用。通过总结学生在“钠及其化合物”单元教学各环节中的表现情况,包括课堂实录、完成表现性任务、以及针对授课学生、同行专家的调研问卷情况,整理了“钠及其化合物”单元教学过程中的相关收获以及反思。相关单元设计的认识可为今后落实“素养为本”的教学提供一定的参考。 相似文献
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在化学课堂中开展社会性科学议题的教学能够发展学生的社会参与意识,结合微项目学习模式,从课堂教学角度出发,构建选定项目、启动项目、实施项目、交流成果等4个教学流程,确立实施教学的核心问题,设计了鲁科版高一化学“物质的性质与转化单元复习课”,进行了基于社会性科学议题的化学微项目学习的实践教学,结合实践的基本情况提出4点反思。 相似文献
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基于“素养为本”视角,以“原子晶体”的教学为例,对教学主题内容、教学现状及学情进行分析;以发展学生化学学科核心素养为主旨确定教学目标;以“微粒-微粒间的相互作用-物质的聚集状态-物质性质”的认识思路为主线,以“模型认知,建构概念-证据推理,归纳性质-微观探析,探究结构-科学史实,揭示价值”的任务型教学流程,达到落实并发展学生化学学科核心素养的目的。 相似文献
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介绍了“乙炔的化学性质”的教学设计思路,展现了如何利用创新实验、丰富素材和问题讨论,帮助学生理解有机物性质和结构之间的关系。主要涉及以下几个环节:(1)通过课前自主预习,从乙炔与乙烯的相似性入手,预测乙炔的性质,了解乙炔的实验室制法;(2)结合2个创新分组实验“基于井穴板的微型化气体连续制备和性质检验装置”“利用真空输液瓶、微型样品瓶和注射器的密闭气体微型反应装置”,教师和学生一起巩固了乙炔的实验室制法,验证了预测的化学性质,丰富了对乙炔性质的感性认知,发现了“乙炔不能使酸性K2Cr2O7溶液褪色”的异常现象;(3)从尝试解释异常现象入手,教师和学生一起从键能、加成比例、聚合后主链结构等多个角度探讨了乙炔与乙烯性质和结构的差异,建立起有机物官能团与性质关系的认知模型;(4)通过尝试利用模型解释2000年诺贝尔化学奖“导电高分子”和2017年度国家自然科学成果一等奖“AIE聚集诱导发光材料” 的结构、性质与应用,教师和学生一起提升了对认知模型的理解建构,感悟了科学研究的乐趣,体会化学科学在促进人类文明发展和社会进步中的重要作用。 相似文献
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The effect of the phase composition of the starting mixture on the formation of the layered perovskite-like compound Bi7Fe3Ti3O21 in the Bi2O3-TiO2-Fe2O3 system is reported. The rate-limiting process in the formation of this compound is reactant mass transfer to the reaction
zone. 相似文献
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Using the method of hydrothermal synthesis,the nanoparticles of magnesium-aluminum spinel were obtained with a crystallite
size of 40–50 nm. The sequence was determined of the chemical transformations under hydrothermal conditions of the initial
magnesium-aluminum hydroxides obtained by co-precipitation, leading to the formation of nanoparticles MgAl2O4. 相似文献
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O. E. Glukhova 《Journal of Structural Chemistry》2007,48(1):S141-S146
The equilibrium state of the C60@C450 nanoparticle was studied. The compound was found to be stable during the encapsulation of C60 tubelene. The motions of tubelene in the confinement potential field of a closed C450 nanotube, namely, the translational motion along the tubule axis and the rotational motion were investigated in detail. It is predicted that there is a nanogyroscope inside C450, rotating in the field of the C60 capsule. Its quantized rotational states were calculated. The nanoparticle structure and energy were investigated by the tight binding method using modified parameters. 相似文献
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S. V. Konovalikhin V. I. Ponomarev 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2016,90(10):2107-2109
The activation energy of displacement of Mg atoms through channels of B25C4Mg1.42 crystals is estimated using quantum chemical calculations (DFT (B3LYP potential), RHF, and UHF methods, 3-21G basis set) of the element of the structure modeling the channel and location of Mg atoms in it. The changes in the activation energy at the replacement of Mg atoms by Na and Li atoms were estimated. The greatest decreasing in the activation energy was detected for Li atoms. The obtained results can be regarded as a theoretical background for development of conducting systems based on B25C4Mg1.42 crystals. 相似文献
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Fateh S. Nandel Balvinder Singh Anil Saran 《International journal of quantum chemistry》1992,42(6):1669-1679
The conformational structure of the tetrapeptide Boc–Aib–Leu–Leu–Aib–OMe has been investigated by the PCILO method. The computational results show the formation of two closed β-turns, both of which are of type III, and the peptide backbone folds into a right-handed 310-helical conformation stabilized by two intramolecular 4 → 1 hydrogen bonds. The helix thus formed generates a pore of ~3 Å along helix axis with hydrophobic amino acid side chains located on the outside of the helix, and this tendency of leucine side chains may enable leucinostatin A to fit into the membrane bilayer. The pore thus formed is cation-selective, and through this pore, the cation can pass only in a single file. 相似文献
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G. A. Bandurkin V. A. Krut’ko G. V. Lysanova M. G. Komova 《Russian Journal of Inorganic Chemistry》2011,56(1):82-92
The cationic networks in the structures of the initial oxides and all binary and ternary compounds forming in the Ln2O3-GeO2-P2O5 systems have been studied. In the phase diagrams of the Nd2O3-GeO2-P2O5 and Er2O3-GeO2-P2O5 systems, the regions of the structural influence of individual compounds with topologically identical cationic networks—anisotropic
(A), combined (C), and isotropic (I)—are united into common areas. The A: C: I area ratio is 1: 1: 1 in the neodymium system
and 1.7: 1: 3.4 in the erbium system. 相似文献
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P. M. Silenko A. N. Shlapak T. V. Tomila A. I. Bykov A. V. Ragulya 《Theoretical and Experimental Chemistry》2011,47(1):9-13
The effect of the production temperature on the morphology and structure of Si3N4 nanofibers was investigated. It was shown that nanofibers produced in the temperature range of 1340–1360°C are amorphous
while those produced at 1380°C and above are monocrystalline. Apart from the principal phase (α-Si3N4) the imide Si2N2NH was also found in the reaction products. 相似文献
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V. A. Nadolinnyi N. V. Chernei A. V. Sinitsyn A. A. Pavlyuk S. F. Solodovnikov 《Journal of Structural Chemistry》2008,49(5):859-864
The binary molybdate Li2Zn2(MoO4)3 of a new crystal type was characterized by EPR, optical spectroscopy, and X-ray diffraction methods. The crystals have the Pnma symmetry group and the lattice parameters a = 5.1139(5) Å, b = 10.4926(13) Å, c = 17.6445(22) Å; Z = 4. The crystals possess scintillation properties; emission is caused by the presence of impurity levels in the forbidden band. The EPR studies of the nature of the impurity centers responsible for the scintillation characteristics of the crystal showed that the centers were Cu2+ ions substituted for zinc ions in the oxygen octahedra. The directions of the main values of the g and tensors (g zz , A zz ) correspond to the direction of O-Cu-O of the oxygen octahedron distorted along the Z axis. The EPR spectra of the copper ions are described by the spin Hamiltonian with the parameters g ‖ = 2.38, g ⊥ = 2.06; A ‖ = 116 G, A ⊥ = 0 G. 相似文献
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The rate constants of the reactions of the chlorine atom with C3F7I (k
1) and CF3I (k
2) have been measured using the resonance fluorescence of chlorine atoms in a flow reactor at 295 K: k
1 = (5.2 ± 0.3) × 10−12 cm3 molecule−1 s−1 and k
2 = (7.4 ± 0.6) × 10−13 cm3 molecule−1 s−1. No iodine atoms have been detected in the reaction products. 相似文献