基于提高学生科学素养的科学实践活动设计与实践——以“果蔬维生素C大比拼”为例

以“果蔬维生素C大比拼”科学实践活动为例,阐述了科学实践活动的设计原则、活动目标设计、教学过程设计、教学实施策略以及活动效果。说明科学实践活动对于培养和提高学生科学素养的独特作用,指出教师应重视科学实践活动的研究与开发,并需不断提高自身的科学素养水平。     

跨学科项目教学案例*——魔力沙

以魔术表演用的沙子为素材,开发了适用于高中选修课程“发展中的化学学科”的具有跨学科性的项目教学案例,该项目弱化理论分析环节后也可以用于初中科学实践活动课程。项目引导学生在更宽广的学科背景下认识物质及其变化的规律,帮助学生拓展视野和思路,综合运用化学、物理等学科的知识分析解决有关问题,发展“宏观辨识与微观探析”“科学探究与创新意识”“科学态度与社会责任”等化学学科核心素养。     

促进科学观念与科学实践协同发展的学生必做实验的教材编写

国内外科学教育界普遍认为,科学观念与科学实践的协同发展是培养学生科学素养的重要途径。教材对于学生必做实验的编排和处理,对于教师的教学设计及实施具有重要的影响。简要介绍了科学观念与科学实践协同发展的内涵,并针对北京师范大学“新世纪”山东科学技术出版社高中化学必修教材中的学生必做实验编写的整体情况和具体策略进行了深入分析,阐释了该教材对于学生必做实验的编写是如何体现科学观念与科学实践的协同发展、彰显这些实验的核心素养发展功能的,并提出了新教材学生必做实验的教学实施建议。     

美国NGSS科学与工程实践构架与化学教学案例——影响化学反应速率的因素

美国《新一代科学标准》（NGSS）强调科学实践的重要性并提出科学与工程实践的关键要素，不仅为科学实践的具体实施提供了方向而且使科学实践的评价标准更加明确。在介绍NGSS科学与工程实践的构架基础上，以“影响化学反应速率的因素”为例分析了科学与工程实践的关键要素在教学中的反映及实施特点，并基于案例分析提出对我国中学化学教学过程设计的借鉴与启示。     

实验教学中科学素质的培养

科学素质是现代人的综合素质的一个重要方面,它是一个人的科学认知水平、科学认知能力、科学实践能力和科学创新能力的综合体现。传统的化学教学存在重视知识,忽视智能、忽视实践、忽视创造的偏向,实际上智能、实践、创造是各种能力的集中体现和综合运用,特别是创新能力,正是当今社会最重要的科学素质,是智力的最高形式,应引起化学教育工作者的高度重视,否则,很难把学生培养成创造型人才。本人试从化学实验教学角度对科学实践能力与创新能力的培养作一初步探讨。     

以“科学和工程实践”视角分析高中化学教科书

以“科学和工程实践”的8大环节和学习者主体性2个维度建立模型,分析上海科学技术出版社出版的高中化学教科书中的实践活动。发现此教科书中的实践十分注重分析环节,能较好发挥学生主体性的环节有：科学实践中的分析解释数据环节;工程实践中的建模、计划、实施调查等环节。但总体上工程实践不足,无论科学实践还是工程实践,在提出问题、设计步骤这2个环节上学生过于被动。据此认为,在化学教科书实践活动的修改或教学优化上,应增强学生的主动性,除了要开展科学探究活动,也要适当增加工程设计等活动。     

外显学科核心素养促进知识向能力和素养的转化——北京师范大学“新世纪”鲁科版高中化学新教材的特点

简要介绍了北京师范大学“新世纪”山东科技版高中化学新教材的总体特点,从教材结构体系和内容的组织编排、学科认识模型和方法的外显、问题任务和系列微项目的设置、学生必做实验及化学科学实践活动的编排、核心素养学科能力表现评价的设计、学科育人素材的选取等方面,具体阐释教材落实课程标准、诠释学科核心素养和体现立德树人的编写策略。     

摩尔概念的历史变迁及其科学价值*

“摩尔”概念的变化历史贯穿人类近代化学以来发展的所有历史,是学科史中科学思维变化的关键性事件,其变化背后的科学实践、思维、决策深刻影响着化学学科的发展。厘清摩尔概念变迁的历史,有助于厘清其背后的哲学与历史对科学认识和科学教学的价值。研究发现,有关摩尔概念的发展史主要分为萌芽期、发展期和成熟期等3个阶段,其历史是科学思维与科学实践结合的典型例证,蕴含丰富的科学决策与论证思想,也是学生概念发现与意义学习的重要材料。     

对科学方法和科学方法教育的再认识——祝贺《化学教育》30周年刊庆

科学方法是科学活动经验升华、程序化、规范化、强化的结果,是科学活动的过程规定性工具。方法的思维是科学方法的精髓。对具体的科学方法进行概括,形成科学方法的适用范围不同的层次。科学方法大体上可以分为经验方法、理性方法和具有补充、完善意义的"第三类方法"以及综合性方法。科学方法有局限性,需要关注方法的改进,注意创新。要搞好科学方法教育,必须以科学方法形成和发展的规律为基础,既要考虑科学方法的特点,也要考虑教育对象的特点。     

基于智能手机的自制浊度仪及其应用

基于透射比浊法原理,设计了基于学生经验、易于学生自制的简易浊度仪。利用智能手机内置的光强传感器获得入射光、透射光数据,结合用标准溶液绘制的标准曲线,可定量测得样品的浊度。自制浊度仪可应用于多种探究实验和科学实践活动,不仅是一个实用的实验工具,更是学生深度学习的过程。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.