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介绍了大学有机化学“强理念、重思维、活课堂、共育人、乐钻研”五维度教学新策略的内涵与实践。以线下教学为主,腾讯会议和慕课为辅助,践行“有机化学是科学也是艺术”的教学理念;采用多循环“疑探式”教学方式,辨析亲电试剂和亲核试剂的多样性;注重培养学生多种科学思维的综合运用;强化“文献预习”“练习讲解”“综合作业”“师生互动”等多个教学环节,加深学生对知识的理解与应用,提升学生在课堂中的参与度,着重培养学生的科学思维和人文素养、自主学习与团队合作精神。 相似文献
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针对学生在学习“依据化学方程式的计算”中普遍存在的“机械记忆解题步骤、怠于探求问题背后深层原因、将化学问题沦为单纯的数学计算”等倾向问题,采用层层深入的问题设置来激发学生深度思维,促使学生将已有知识链条化、结构化,同时将内在的思维链条外化,逐步搭建解决问题的一般思维模型,以此促进学生对化学核心概念和原理的深度理解。在初步建模的基础上,进一步引导学生对“化学反应中含杂质物质质量的计算”的具体问题再次建模,逐步形成“依据化学方程式的计算”类问题的解决图式。调查数据表明,经过思维建模及其应用有效发展了学生的深度思维能力和问题解决能力。 相似文献
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针对学生在学习“酸和碱的中和反应”中普遍存在的“被动接受具体知识、缺失开展真实科学探究的思路、机械记忆中和反应规律、缺乏批判质疑精神及高阶思维能力不足”等倾向问题,设置了驱动性问题链协助学生搭建“情境问题”与“真实的科学探究”间的思路桥梁,在深度的科学探究中发展学生的发散性思维、有序思维、多角度分析问题、设计创造思维、逻辑严密的推理及评价反思等高阶思维能力。课堂教学中营造轻松、舒适的交流讨论环境,有益于学生之间碰撞出思维的火花、激发出创造的灵感。课堂观察表明,深度科学探究教学的实施,有效提升了学生的高阶思维能力及解决问题的能力。 相似文献
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把“溶液”放到完整学科体系中,利用本原问题驱动,调取新授课储备的、与新问题情境匹配的学科理论、模型,将“核心概念、学科任务、认识角度、认识路径、能力活动、化学基本观念”融合,借助学科思维方式、方法,打通纵横联系,找寻基本规律,在思维碰撞中对自身原有认识加以修正、完善发展,形成“核心概念功能化,解决问题思路化”的系统思维模型。在学科核心素养统领下,落实核心概念功能价值演变的初中化学复习课教学。 相似文献
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在搭建初中定量实验分析的思维模型的基础上,以“测定混有碳酸钠的氯化钠样品中碳酸钠含量”教学为例,在 “总问题”与“子问题”驱动下,引导初中生逐步建立解决定量实验问题的一般方法,提升对定量实验的设计、评价与改进能力,形成具有迁移价值的关键性能力。 相似文献
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Kerstin Schulze‐Matthi Jürgen Bendig Petra Neubauer Burkhard Ziemer 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(6):e257-e258
The bonding geometry of sulfur in the cations of the title compounds, C8H11S+·CF3SO3? and C13H13S+·CF3SO3?, respectively, is similar and is independent of the ratio of the Me/Ph substituents. As expected, in both cations, the S—Ph bonds are somewhat shorter than the S—Me bonds. In both crystal structures, the interaction between cations and anions is similar. 相似文献
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John Nicolson Low George Ferguson James L. Wardell 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):e317-e317
In the title compound, [Sb(CH3)(C6H5)3]BF4, there are four independent cations and anions in the asymmetric unit. The geometry around the Sb atom is distorted tetrahedral, with Sb—C distances in the range 2.077 (4)–2.099 (10) Å and angles at the Sb atom in the range 103.3 (3)–119.0 (4)°. 相似文献
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Maren Pink Doyle Britton Wayland E. Noland Matthew J. Pinnow 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):1271-1273
The molecular structures of the title compounds, 2,4,6‐trichlorophenylisonitrile (IUPAC name: 2,4,6‐trichlorophenyl isocyanide), C7H2Cl3N, and 2,4,6‐trichlorobenzonitrile, C7H2Cl3N, are normal. The two structures are not isomorphous, but do contain similar two‐dimensional layers in which pairs of molecules are held together by pairs of Cl?CN [3.245 (3) Å] or Cl?NC [3.153 (2) Å] interactions. The two‐dimensional isomorphism is lost through different layer‐stacking modes. 相似文献
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Dianne D. Ellis Anthony L. Spek Pieter Imhoff Cornelis J. Elsevier 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(7):836-837
The cationic part of the homodifunctional aminophosphoranyl ligand, C41H41N2P2+·I?, shows interesting features associated with the N—P—C—P—N skeleton. The P—C(H) bond distances [1.696 (3) and 1.697 (3) Å] possess partial double‐bond characteristics. The nature of the P—C(H) and P—N bonds suggests that the positive charge is only distributed around the P—C—P atoms. The structure has near twofold symmetry through the central methylide‐C atom. 相似文献
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Magorzata Hoyska Tadeusz Lis 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(12):m648-m650
Ethyltriphenylphosphonium perrhenate, (C20H20P)[ReO4], and (iodomethyl)triphenylphosphonium perrhenate, (C19H17IP)[ReO4], have been crystallized from 2‐propanol. Both crystal structures consist of phosphonium cations and perrhenate anions. The cations show the typical propeller‐like geometry. In both crystals, the positions of the nearly tetrahedral anions are stabilized by weak C—H⋯O hydrogen bonds, and for the latter compound, I⋯π interactions also occur. 相似文献
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Russell G. Baughman Kenneth L. Martin Rajendra K. Singh James O. Stoffer 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(2):o103-o106
In 2,4‐dihydroxybenzaldehyde 2,4‐dinitrophenylhydrazone N,N‐dimethylformamide solvate {or 4‐[(2,4‐dinitrophenyl)hydrazonomethyl]benzene‐1,3‐diol N,N‐dimethylformamide solvate}, C13H10N4O6·C3H7NO, (X), 2,4‐dihydroxyacetophenone 2,4‐dinitrophenylhydrazone N,N‐dimethylformamide solvate (or 4‐{1‐[(2,4‐dinitrophenyl)hydrazono]ethyl}benzene‐1,3‐diol N,N‐dimethylformamide solvate), C14H12N4O6·C3H7NO, (XI), and 2,4‐dihydroxybenzophenone 2,4‐dinitrophenylhydrazone N,N‐dimethylacetamide solvate (or 4‐{[(2,4‐dinitrophenyl)hydrazono]phenylmethyl}benzene‐1,3‐diol N,N‐dimethylacetamide solvate), C19H14N4O6·C4H9NO, (XII), the molecules all lack a center of symmetry, crystallize in centrosymmetric space groups and have been observed to exhibit non‐linear optical activity. In each case, the hydrazone skeleton is fairly planar, facilitated by the presence of two intramolecular hydrogen bonds and some partial N—N double‐bond character. Each molecule is hydrogen bonded to one solvent molecule. 相似文献
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Phase equilibria in the LiF-LiCl-LiVO3-Li2SO4-Li2MoO4 system have been studied by differential thermal analysis. The eutectic composition has been determined as follows (mol %): LiF, 17.4; LiCl, 42.0; LiVO3, 17.4; Li2SO4, 11.6; and Li2MoO4, 11.6, with the melting temperature equal to 363°C and the enthalpy of melting equal to (284 ± 7) kJ/kg. 相似文献
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L. Abbas L. Bih A. Nadiri Y. El Amraoui H. Khemakhem D. Mezzane 《Journal of Thermal Analysis and Calorimetry》2007,90(2):453-458
Thermal and chemical durability studies of the phosphate glasses belonging to the binary MoO3-P2O5 and the ternary K2O-MoO3-P2O5 systems are reported. The chemical resistant attack tests carried out on the free alkaline MoO3-P2O5 glasses show that the glass associated with the P/Mo ratio 2 has the high chemical durability. It shows also a high glass
transition temperature value. The above findings are interpreted in terms of the cross-link density of the glasses and the
strength of the M-O bonds (M=P, Mo).
The influence of K2O addition on the properties (density, T
g, durability) of this binary high water resistant glass is studied. It is found that the chemical durability along with the
other physical properties are reduced by the incroporation of K2O in the glass matrix. The results were explained by assuming the formation of non-bridging oxygens and weak bonds. The mechanism
of the dissolution of these glasses is proposed. 相似文献
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Anthony Linden C. Kuan Lee A. S. Muhammad Sofian 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1098-1100
At 160 K, the glucopyranosyl ring of the title compound, C20H28ClIO13, has a near‐ideal 4C1 conformation and the fructofuranosyl ring has a twist 4T3 conformation. The two hydroxy groups are involved in intra‐ and intermolecular hydrogen bonds, with the latter interactions linking the molecules into infinite one‐dimensional chains. The absolute configuration of the molecule has been determined. 相似文献