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1.
以“淀粉综合利用”为项目主题,开展高中化学“基本营养物质”中糖类的教学。学生通过完成“家庭制糖”“家庭制米酒”“家庭酿醋”等9个项目任务,在实践活动和课堂教学中掌握糖类水解的原理、糖类的性质及其转化。通过认识聚乳酸塑料及其使用价值、自制环保材料等实践活动,体会淀粉的综合利用在环境保护中起到的积极作用,落实科学态度与社会责任的化学核心素养。  相似文献   

2.
<正>如今有机化学已经深入到人类生活的方方面面,例如:构成生命体的基本物质氨基酸、核酸,常见的药物、食品等均为有机化合物;烃类是石油化工中的重要的原料…….有机化学是以含碳化合物为核心的科学,C—H键是构成有机化合物的重要基本单元,实现简单、高效、高选择性C—H键,尤其是惰性C—H键的直接官能团化,可以有效减少化合物合成步骤、提高合成转化的原子经济性,甚至可能实现常规方法难以完成的化学合  相似文献   

3.
围绕传统民间小吃“甜酒酿”, 以其生产过程中的真实问题为线索,设计甜酒酿“甜味来源-甜味调控-酒味探析”的任务线,引导学生明晰糖的分类与转化,并通过实验探究、糖类营养与工业价值的讨论,培养学生解决综合问题的能力。进而构建与食品生产和价值相关的基本营养物质认识实践模型,促进由知识到核心素养的转化。  相似文献   

4.
当前“盖斯定律”的教学中,注重加和法、虚拟路径法等解题模型的教学,缺乏在真实情境中对物质转化及其能量关系的理解,学生无法感受到盖斯定律在生产中的价值。本文以“能量视角下煤的气化对于提高煤的燃烧效率的意义”为研究主题,通过分析建模、实验验证、情境回归等认识并应用盖斯定律,从能量视角再认识煤的气化对于提高煤的燃烧效率的意义,并且认识到利用化学反应可以实现对能量进行调控,如对工业废热的再利用,深化能量守恒观和能源节约意识,达成提升学科核心素养的目标。  相似文献   

5.
以“探究易拉罐中金属材料的成分”为项目主题,开展高中化学“金属材料”的学习。学生通过“探究可乐易拉罐罐体和罐盖的耐腐蚀性”“探究罐体金属材料是纯铝还是铝合金”“探究罐体铝合金中是否含铁”“探究不同用途铁合金性能和组成的差异”“认识新型合金”等5个项目任务,将铝合金、铁合金及新型合金的学习转化为持续的探究与实践,形成“组成与结构决定性能,性能决定用途”的核心观念,养成沟通与合作的习惯,发展批判性思维,提升问题解决能力。真实而具挑战的任务驱动、自主而开放的学习过程、全程而多元的评价方式,是顺利完成本项目的关键。  相似文献   

6.
杨玉琴  倪娟 《化学教育》2019,40(23):23-29
“证据推理”与“模型认知”作为重要的化学学科思维方法,是化学学科核心素养的重要组成部分。证据推理贯穿于科学探究的过程,具有假说特性的“模型”,其构建和发展皆必须建立在证据推理的基础上。该核心素养的培育有赖于探究学习的深入开展,需重视证据推理在整个过程中的统摄作用、以模型认知搭建宏微联系以及通过高质量的对话提升论证水平等。  相似文献   

7.
高杰  刘银 《化学教育》2015,36(9):26-29
以“暖宝宝”为情境素材,以实验探究和小组讨论为主要活动方式,设计并实施了“金属的电化学腐蚀与防护”的探究教学.在教学设计中,详述了2个核心探究: “暖宝宝”发热原理的探究和金属电化学防护原理的探究,分析了核心探究活动在培养学生高级思维和创新能力方面的功能价值,反思了教学素材的选取和整合、情境创设的全程性及哲学思想的渗透对激发学生学习兴趣、培养学生的创新动机情感和创造力等方面的重要意义.  相似文献   

8.
基于元素分析仪、质谱仪、红外光谱仪等现代分析仪图谱,提出葡萄糖分子结构的可能假设,通过实验加以证实,再结合1H-NMR图谱佐证葡萄糖分子结构,从而建立葡萄糖分子结构的探究模型,为有机化合物分子结构探究提供范式。  相似文献   

9.
基于有机化合物主题学科核心素养和关键能力的系统构成模型,提出促进学生化学学科能力发展的有机化合物主题大单元整体教学设计框架,以“揭秘阿司匹林”复习教学为例,从大单元教学目标确定、教学内容确定、情境素材选择、学科能力活动设计等阐述了大单元整体教学设计过程。通过案例设计和教学实践,对比分析教学效果,进而探讨促进学生有机化合物主题化学学科能力发展的大单元整体教学策略。  相似文献   

10.
宁晓强  李聪聪 《化学教育》2022,43(23):36-42
以波义耳研究燃烧的史实为背景,创新设计燃烧条件的探究实验,并提出“条件叠加式”燃烧条件探究新思路。以“燃灭控”为主线,一以贯之地显性化“条件是认识化学反应的一种基本视角”,落实“在一定条件下通过化学反应可以实现物质转化”的化学观念。基于调控化学反应思想创新设计“燃旺弱灭”反应控制视域,统整开展“情境”“活动”与“任务”三位一体的学习活动。重置教材实验的教学价值取向,结合燃烧的形式美、汉语言文字解读,将化学学科知识与美育、汉语言文化领域跨领域融合。  相似文献   

11.
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   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

16.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

17.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

18.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.  相似文献   

19.
20.
设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。  相似文献   

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