例谈避免"化学与生活"模块教学的科普化

高中化学新课程结构分为必修和选修2部分,"化学与生活"属于其中的一个选修模块。广大化学教师在实施此模块过程中遇到的普遍问题是:感觉没有多少化学知识,大部分教学内容倾向于科普介绍。通过"垃圾的妥善处理与利用"教学案例探讨避免"化学与生活"模块教学的科普化的教学策略和注意事项。     

对人教版《化学反应原理》教科书中一些习题及答案的商榷

在教学过程中我们发现,人民教育出版社2007年2月第3版普通高中课程标准实验教科书<化学选修4化学反应原理>及其配套教师教学用书上一些习题和参考答案有错误,因此提出分析与教材编写者商榷,并供使用此选修模块的师生参考.     

三套选修模块教材《化学与生活》中的化学实验比较

人民教育出版社、江苏教育出版社和山东科学技术出版社均出版了《化学与生活》选修模块教材。3套教材中的实验具有内容联系实际、体现探究性和多层次性的特点。文中对3套教材中的实验按照化学与健康、生活中的材料、化学与环境保护三大主题,以及探究性实验、验证性实验、探究和验证相结合的实验等进行了分类统计和比较分析,以利于化学教师在教学中充分利用教材资源。     

“实验化学”模块教育价值分析与教学尝试——以苏教版《实验化学》为例

在分析"实验化学"模块教育价值的基础上,探讨"实验化学"模块的教学方法,并从教材、教师、评价等视角说明在教学过程中存在的问题及其对策。     

普通高中化学选修模块选学模式及选学情况探析

在基础教育新一轮课程改革中,选修课程的落实是其中一个突出问题.教育部及各地教育行政部门分别通过各学科的"课程标准""选学指导意见"对高中选修模块提出了学习建议.主要针对化学学科的"课程标准"及各省(市、自治区)"选学指导意见"对化学学科的选学模式进行了比较.分析可知,高中化学选学模块在实施中形成了必选模式和非必选模式,同时也呈现出选修课程必修化,6个选修模块的选学不均,高考左右着模块选学等特点.     

新旧人教版教材选修模块“电化学”内容的比较分析

通过对新旧人教版教材选修模块“电化学”内容比较分析,新版本教材在情境素材选取上更加关注社会热点、科学前沿的化学问题,在教学内容编排上更加注重知识的衔接,在教材栏目设置上更加注重认识思路和方法的提炼与概括,在实验内容安排上更加凸显化学实验的育人功能。新版本教材对实际教学提出了更高的要求。建议教师在实际教学中重视认识思路和认识方法的提炼和外显、优化情境素材的选取、发挥化学实验的化学学科核心素养培养功能。     

高中选修模块教材《实验化学》三种版本的比较分析

对人教版、山东科技版、苏教版3种高中化学选修模块教材《实验化学》的结构和内容做了归纳和对比,从教材编写线索、实验分类、学习栏目、插图、习题等几个方面进行比较分析,并提出了几点建议,以利于化学教师对新课标的理解及教材的选用。     

高中化学课程模块设置的反思及建议

结合普通高中新课程化学学科模块教学的实际情况,分析了现行化学学科模块教学体系中知识体系松散、实验教学弱化以及教科书繁多等主要问题和不足,提出了必修模块重学科基础及知识体系、选修模块重个人爱好和专业发展等改进和优化高中化学学科模块体系的若干建议。     

尊重学生的认知规律 因材施教

《普通高中化学课程标准实验教科书（山东科技版）》必修和选修8个模块教材已全部出版。为了收集各方面的意见和建议,该套教材编写组在全国部分城市和地区进行了试教工作。我校化学组承接了《化学与生活》、《物质结构与性质》、《化学反应原理》3个选修模块中的部分章节的试教课题,本人选择的是《物质结构与性质》第3章中的第1节“认识晶体”的教学课题。     

厘清核心概念及其学习进程:分析教材的新视角——以中学化学“电化学基础”教学内容为例

以一线教师对人教版高中化学选修4《化学反应原理》教材的"化学电源"教学中关于学生认识发展的教学困惑为切入点,做了基于核心概念的中学化学"电化学基础"教学内容分析,并由此梳理出从初中化学到高中选修4学段学生对该内容的学习进程。以"化学电源"教学的再设计,说明厘清核心概念及其学习进程对促进学生认识发展的教学价值。     

"Alpha"-, "beta"- and "delta"-anhydrodigitoxigenin

The syntheses of 3β-hydroxy-5β-carda-14, 20:22-dienolide (= «β»-anhydro-), 3β-hydroxy-5β-carda-8:14, 20:22-dienolide (= «α»-anhydro-) and «δ»-anhydro-digitoxigenin (= probably 3β-hydroxy-5β, 14β-carda-8, 20:22-dienolide) by the best ways known to date, have been described. «δ»-Anhydro-digitoxigenin represents the thermodynamically most stable isomer. In this isomer the double bond in position 8 is unaffected by hydrogenation with Pt in acetic acid; with perbenzoic acid an epoxide results from which, on hydrogenation, the double bond can be regenerated in its original position. Analogous reactions are known to occur in the 8:14-epoxides.     

化“材”为“筑”

Chemistry is a central, practical and creative discipline. The development of chemistry plays an important role in the progress of science and society, as well as the improvement of the quality of human life. This paper introduces the chemical knowledge of stone, concrete, glass and other inorganic nonmetallic building materials by the anthropomorphically story. Taking nanomaterials as an example, the prospect of building materials development in the future is put forward.     

Making "wheels" and "cubes" from triangles

[Mn(IV)Mn(II)3] triangular units directed by the presence of tripodal alcohols self-assemble in the presence of azide and acetate ligands to form either a [Mn24] "wheel" or a [Mn32] "cube".     

"Turn-on" fluorescent sensing with "reactive" probes

Chemical probes are valuable tools for the investigation of biochemical processes, diagnosis of disease markers, detection of hazardous compounds, and other purposes. Therefore, the development of chemical probes continues to grow through various approaches with different disciplines and design strategies. Fluorescent probes have received much attention because they are sensitive and easy-to-operate, in general. To realize desired selectivity toward a given analyte, the recognition site of a fluorescent probe is designed in such a way to maximize the binding interactions, usually through weak molecular forces such as hydrogen bonding, toward the analyte over other competing ones. In addition to such a supramolecular approach, the development of fluorescent probes that sense analytes through chemical reactions has witnessed its usefulness for achieving high selectivity, in many cases, superior to that obtainable by the supramolecular approach. Creative incorporations of the reactive groups to latent fluorophores have provided novel chemical probes for various analytes. In this feature article, we overview the recent progress in the development of turn-on fluorescent probes that are operating through chemical reactions triggered by target analytes. Various chemical reactions have been implemented in the development of many reactive probes with very high selectivity and sensitivity toward target analytes. A major emphasis has been focused on the type of chemical reactions utilized, with the hope that further explorations can be made with new chemical reactions to develop reactive probes useful for various applications.     

"Decoking" of a "coked" zeolite catalyst in a glow discharge

'Decoking' of a 'coked' zeolite catalyst in a glow discharge in oxygen is investigated. The 'decoking' process involves reactions of atomic oxygen (O atoms) with 'coke' and yields gases such as CO, CO₂ as well as other gaseous products that could be easily pumped out.Three different modes of discharge were investigated including a static mode, a flowing-gas mode, and a periodic-purge mode where the oxygen and other gaseous products of the discharge were replaced by fresh O₂ gas after short but regular intervals of time. In some cases, additional heating was also used to provide base temperatures of the order of 100 °C to facilitate penetration of oxygen atoms into the inner layers and cages of the zeolite catalyst.This paper presents some results of spectroscopic analytical techniques used to monitor the atomization of oxygen, oxidation of 'coke', and to confirm the process of 'decoking'. More specifically, radiation emission on the 3 s ⁵S– 3p ⁵P transitions of O around 777.2–777.5 nm were selected for monitoring the atomization of O₂. On the other hand, X-ray photo-electron spectroscopy (XPS) was used to determine the amount of residual carbon and extent of 'decoking'. Furthermore, evolution of CO and CO₂ gases as a function of time was systematically monitored in real time. For CO, the 451.1 nm band head belonging to the B¹ - A¹ bands of the Angstrom system of the CO spectrum was used, while for CO₂, the band head at 353.4 nm belonging to the CO₂⁺ spectrum was used. The rates of evolution of CO and CO₂ were related to the rate of 'decoking' of the catalyst. It is noted that in the periodic-purge mode, about 63% of the total yield of CO from a given sample of the catalyst appears in the first 3-min exposure to discharge whereas it takes up to 15 min to remove nearly 94% of the removable carbon under our experimental conditions.     

营养化学课程翻转课堂的探索与实践

With its tailored learning content, flexible learning environment and directed teacher guidance, the flipped classroom in "nutrition chemistry" has effectively solved the problems of students' specialty, large number and limited time in the course of elective course. The teaching mode based on the cultivation of students' ability and the core of improving scientific literacy was constructed.     

Size evolution study of "molecular" and "atom-in-cluster" polarizabilities of medium-size gold clusters

A study on static polarizabilities for a family of gold clusters (Au(n), n = 6, 12, 20, 34, 54) is presented. For each cluster, a density functional theory perturbation theory calculation was performed to compute the cluster polarizability and the polarizability of each atom in the cluster using Bader's "quantum theory of atoms in molecules" formalism. The cluster polarizability tensor, α(cluster), is expressed as a sum of the atom-in-molecule tensors, α(cluster)=∑(Ω)α(Ω). A strong quadratic correlation (R(2) = 0.98) in the isotropic polarizability of atoms in the cluster and their distance to the cluster center of mass was observed. The cluster polarizabilities are in agreement with previous calculations.     

梦萦魂牵--《化学通报》复刊30年

哲学家和物理学家都喜欢研究和讨论“时间” ,时间之矢告诉人们光阴冉冉不复返 ,矢者失也。然而人们却总想回忆 ,寻找那些美好的或沮丧的过去 ,是安慰或自娱吧。我一直相信生活总是向前的 ,社会总是进步的 ,就和宇宙不停地膨胀一样。《化学通报》复刊已经 3 0年了 ,既然是复刊 ,必然先有停刊。历史总是把破坏和重建放在一起考虑的 ,才能找出规律。人们都说 2 0世纪是自然科学大发达的时代 ,然而 2 0世纪又是人类社会灾难最多的时代。正因如此 ,才促使科学多极化地、多样性地发展起来 ,从欧洲到美洲到亚洲 ,一点点 ,慢慢地扩散开来 ,也许 ,真…