人文精神与现代技术在"晶体的空间结构"一课中的融合

化学中如何渗透人文精神 ?这节课要完成的教学目的很难 ,充斥着立体化学中的数学思想 ,枯燥、乏味。为使这堂课上好 ,迫使我思考应如何引发学生学习的兴趣、激发学生的情感 ,我用了化学史 ,结果枯燥乏味的内容被化学人文韵味感化了 ,一节课的主要问题解决了。有的课讲究渐入佳境 ,但这节课的课题较难 ,内容较深 ,如果课的开始不能吸引住学生 ,整堂课可能会显得乏味枯燥 ,我想用一段精彩的引言在课的发端就掀起高潮 ,使学生立即进入兴奋状态 ,最后决定用C60 的发现史作为开端。“2 0世纪 80年代初 ,科学家正热衷于研究碳原子团簇 ,其中包括…     

观摩活动课"小河被污染了"有感

“角色扮演活动——小河被污染了”是新编高中教材要求的一节学生活动课。笔者通过参与2个学校十几个班的学生活动,总结出了本次活动课开展的方法与应该注意的问题。     

"SO2的性质"教学设计——物质性质教学的一般策略

1　教学设计的构思在中学教材中 ,二氧化硫的地位可谓是“重中之重” ,课本中详尽描述了它的许多性质 ,但与之相关的贴近人们生活生产、食品卫生、生存环境等方面的内容却涉及很少。如全球关注的“酸雨”问题、食品业中的“化妆品”、矿物燃料的“脱硫技术”等等 ,事实上 ,这些内容对于有一定探索精神的高中学生来说具有极强的诱惑力。本节课就是以“酸雨”为背境 ,设计系列探究性问题 ,激发学生的探究热情 ,拓展学生的视野 ,开启学生的才智 ,让学生在“解决问题———归纳知识———提炼方法———再解决问题”过程中暴露分析策略、优化分…     

运用微粒观开发复分解反应教学价值的实践与研究

在酸、碱、盐教学中以复分解反应条件教学为例, 应用“微粒观”统领酸、碱、盐教学。基于“微粒观”构建了本节课的知识结构层级图, 剖析了学生的认识发展过程, 通过教学实践总结、归纳了若干教学策略, 从而突破学生学习难点, 提高学生的迁移和应用能力, 并为高中进一步学习离子反应做好铺垫。     

关於氯化氢、盐酸教学的一些意见

教学上的首要问题在於对大纲精神的掌握与教材的深入。只有如此,才能抓住教材的重点,教材中各个概念的前後有机联系,才能傅授给学生一个明确而完整的知识。所以,每一节课的讲授,必须注意到前节课的知识是怎样地为这节课打下基础,这节课又是怎样地为下节课打下基础。自然一节课中新课的讲授是主要的一环。但新課的讲授是建立在系统性原则上的。如此,新课的进行才能顺利,学生的接受才感到容易。高中第一册氯化氢的教学,它是关联到氯一节教学中的氯与氢的化合这一概念的。大纲是这样指出的,教材也是这样着重编写的。只氯与氢的化合就安排了     

简易方法制备NaCl晶体的技巧

纯净的NaCl是什么样子的?许多中学生头脑中首先反映出试剂瓶中白色粉末以及食用精盐的形象,很少反映出晶莹立方形晶体的印象,甚至某些大学生当见到一块具体的NaCl单晶时也觉得比较新奇。对NaCl晶体缺少感性认识,可以说是中学教学和大学生学习中存在的普遍性问题。在现行高级中学化学教科书(甲种本)第一册,第二章的第二节中已经涉及到“纯净的氯化钠的晶体呈立方形,……”。建议教师在这一节教学中出示一块NaCl单晶体,增加学生对NaCl晶体的感性认识,为此,介绍一点在普通实验条件下,简而易行制备NaCl晶体实验的技巧。     

“萃取”教学的2个问题与对策

萃取作为高中生进入高中最先接触的新知识,是“化学必修1”第一章(从实验学化学)第一节(化学实验基本方法)的2个难点之一(另一难点为粗盐提纯中试剂的顺序).在教学中,学生理解与掌握得好坏不仅影响成绩,而且关乎学生学习兴趣的发展.如果依据新课程理念,从教师教的角度剖析实际教学过程,将发现萃取的教学过程在教材的处理、概念的形成等方面仍存在一些值得探讨的问题.     

基于学习进阶理论的“有机化学基础”绪言课教学设计

<正>1 教学主题内容分析本节课是高中化学选择性必修3“有机化学基础”模块的绪言课,也是学生从必修走向选择性必修的进阶过渡课。其教学内容对应人教版教材的“引言”,对应鲁科版教材的“第1节 认识有机化学”。鉴于绪言课的作用是明确模块的认识角度,发展学生的认识水平,本节课结合人教版提供的线索及鲁科版呈现的史实素材,     

石墨是属于原子晶体吗?

人民教育出版社出版的五年制中学高中课本《化学》第一册(1982年12月第1版)123页中写道:“金刚石和石墨都属于原子晶体”。石墨属于原子晶体吗?该书对原子晶体的定义是“相邻原子间以共价键相结合而形成空间网状结构的晶体,叫做原子晶体”。接着,该书分析石墨晶体的结构是“石墨的晶体是层状结构,……在同一层内,相邻的     

“盐类的水解”教学设计

1教学内容分析本节教材是本章教材的教学重点和难点,是学生已学习过的弱电解质的电离、水的电离平衡以及化学平衡移动原理等知识的综合应用。本节课的教学目标是指导学生建立盐类的水解的概念,初步了解盐类水解的规律。     

“单晶结构分析实践”课程的教学探索

介绍了为研究生开设“单晶结构分析实践”课程的背景和必要性,阐述了该课程的课程定位、教学内容、教学方法和考核评价体系.实践证明,采用理论与实践并重的课程教学模式,有利于提高学生的综合素养和单晶结构分析能力;针对不同内容采用灵活多样的教学方法,可以激发学生的学习兴趣,调动学生的学习积极性;多模式的过程性考核评价体系有助于提高课程的教学质量.     

毛细微模塑法制作聚合物微球的有序结构

用毛细微模塑法在玻璃基片上组装了聚苯乙烯微球紧密的有序阵列.扫描电镜观察了组装后的微球排列.结果表明,在毛细通道的出口端,聚苯乙烯的微球堆积得紧密有序.毛细通道的尺寸,环境温度和聚合物微球乳液的浓度是毛细微模塑法的主要影响因素.     

Crystal structures and properties of mutagenic N-acyloxy-N-alkoxyamides--"most pyramidal" acyclic amides

X-Ray data for two N-acyloxy-N-alkoxyamides, a class of direct-acting mutagens, indicate extreme pyramidalisation at the amide nitrogen in keeping with spectroscopic and theoretically determined properties of amides with bisoxosubstitution at nitrogen. The combined electronegativity of two oxygens leads to average angles at nitrogen of 107.8 and 108.1 degrees and [chiN] of 66 degrees and 65 degrees. The sp3 nature of nitrogen results in negligible amide resonance as evidenced by long N-C(O) bonds, high IR carbonyl stretch frequencies, carbonyl 13C NMR data and very low amide isomerisation barriers. In addition, conformations in the solid state support a strong n(O)-sigma*(NOAc), anomeric interaction as predicted by molecular orbital theory. HF/6-31G* calculations on formamide, N-methoxyformamide and N-formyloxy-N-methoxyformamide support these findings.     

"我"——"三草酸合铁(Ⅲ)酸钾晶体"的生长及影响因素

This article tries to personify potassium ferrioxalate crystal as "I" to describe the formation process and the factors affecting the growth of potassium ferrioxalate crystal. After growing into beautiful green crystals, I dreamed I was participating in the jewelry beauty contest. A serious of wonderful conversations between emerald and I revealed the properties and applications of potassium ferrioxalate crystal. It inspires and guides students to understand the growth of crystals and their properties, and it also stimulates students' interest in studying chemistry.     

Synthesis,Crystal Structure and Biothiols Detection Capability of a New “off-on” Fluoresent Probe

Biothiols such as cysteine(Cys), homocysteine(Hcy) and glutathione(GSH) act as critical roles in maintaining biological redox homeostasis, which is crucial for a plenty of physiological and pathological processes. Therefore, the detection of biothiols is very important and beneficial for many applications. Herein, we have designed and developed a new crystal dimethyl 4-(2,4-dinitrophenylsulfonyloxy)pyridine-2,6-dicarboxylate(P) with 2,4-dinitrobenzene-1-sulfonyl(DNBS) pendant for light-up and detection of biothiols(Cys was selected as the analyte model). The fluorescence "off-on" switch is triggered by the cleavage of DNBS unit by the interaction with biothiols via nucleophilic aromatic substitution reaction. The turn-on fluorescent probe exhibited excellent selectivity and sensitivity toward biothiols.     

从大概念“尺度与结构”角度构建深度思维课堂——以“晶体结构”为例

氯化钠与氯化铯的阴阳离子个数比相同但晶胞结构却有很大差别。用模型建构、数学计算等方式并融合“尺度与结构”等大概念思维,引导学生循着科学家的科学研究方式思考问题。     

Crystal chemistry and stability of "Li7La3Zr2O12" garnet: a fast lithium-ion conductor

Recent research has shown that certain Li-oxide garnets with high mechanical, thermal, chemical, and electrochemical stability are excellent fast Li-ion conductors. However, the detailed crystal chemistry of Li-oxide garnets is not well understood, nor is the relationship between crystal chemistry and conduction behavior. An investigation was undertaken to understand the crystal chemical and structural properties, as well as the stability relations, of Li(7)La(3)Zr(2)O(12) garnet, which is the best conducting Li-oxide garnet discovered to date. Two different sintering methods produced Li-oxide garnet but with slightly different compositions and different grain sizes. The first sintering method, involving ceramic crucibles in initial synthesis steps and later sealed Pt capsules, produced single crystals up to roughly 100 μm in size. Electron microprobe and laser ablation inductively coupled plasma mass spectrometry (ICP-MS) measurements show small amounts of Al in the garnet, probably originating from the crucibles. The crystal structure of this phase was determined using X-ray single-crystal diffraction every 100 K from 100 K up to 500 K. The crystals are cubic with space group Ia3?d at all temperatures. The atomic displacement parameters and Li-site occupancies were measured. Li atoms could be located on at least two structural sites that are partially occupied, while other Li atoms in the structure appear to be delocalized. (27)Al NMR spectra show two main resonances that are interpreted as indicating that minor Al occurs on the two different Li sites. Li NMR spectra show a single narrow resonance at 1.2-1.3 ppm indicating fast Li-ion diffusion at room temperature. The chemical shift value indicates that the Li atoms spend most of their time at the tetrahedrally coordinated C (24d) site. The second synthesis method, using solely Pt crucibles during sintering, produced fine-grained Li(7)La(3)Zr(2)O(12) crystals. This material was studied by X-ray powder diffraction at different temperatures between 25 and 200 °C. This phase is tetragonal at room temperature and undergoes a phase transition to a cubic phase between 100 and 150 °C. Cubic "Li(7)La(3)Zr(2)O(12)" may be stabilized at ambient conditions relative to its slightly less conducting tetragonal modification via small amounts of Al(3+). Several crystal chemical properties appear to promote the high Li-ion conductivity in cubic Al-containing Li(7)La(3)Zr(2)O(12). They are (i) isotropic three-dimensional Li-diffusion pathways, (ii) closely spaced Li sites and Li delocalization that allow for easy and fast Li diffusion, and (iii) low occupancies at the Li sites, which may also be enhanced by the heterovalent substitution Al(3+) ? 3Li.     

液晶化学

液晶在近30年来受到科技界广泛关注,人们对它的性质、合成、用途进行了深入的研究,使其在现代科技领域占据重要地位。本文对液晶的性质及用途进行论述。     

聚苯乙烯结晶及其晶型转化

介绍了等规和间规聚苯乙烯的合成、晶型及晶体结构研究的进展情况。重点对高间规度聚苯乙烯的各晶型及其相互转化进行了综述。