共查询到20条相似文献,搜索用时 62 毫秒
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对农林大学“有机化学实验”课程教学的模式进行了探索.采用了第一课堂教学平台加第二课堂教学平台的教学模式.充分有效利用第一课堂平台的同时也积极拓展第二课堂的教学功能,既解决学时不足,又达到了教学目的.本课程教学模式的改革与实践给学生提供了个性发展的空间,满足了不同层次不同专业学生的需求,使学生建立了初步的科学研究的基本方法和思想.进一步激发了学生自主的、积极的思考意识,教学实践表明,新的有机化学实验体系的形成,综合性、设计性和开放性实验的开设,使有机化学实验课程更适合高素质人才培养的需要. 相似文献
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通过介绍混合教学模式在有机化学实验课程教学中的设计、实施情况及效果评价与反馈等内容,与大家分享混合教学模式在有机化学实验课程教学中的应用经验与思考。 相似文献
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针对我校有机化学实验课程传统教学模式中存在的弊端,探索了激励机制辅助的"翻转课堂"教学模式,并以正溴丁烷的制备实验为例,介绍了课前、课中以及课后的教师和学生工作内容以及教学评价。实践表明:激励机制辅助的"翻转课堂"教学模式,极大地调动了学生自主学习的积极性和主动性,且激励机制可以更有效地保证"翻转课堂"的顺利实施。 相似文献
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2015年南开大学提出了"讲一练二考三"新理念,旨在从教学方式、教学内容和考核方式等方面对本科教学进行改革,切实提高教学质量。"讲一"要求教师精讲决定实验成功的关键内容,强化学生主动学习能力;"练二"要求对实验内容进行合理安排,增加学生实践机会;"考三"则要求考试内容不限于教材内容,注重将学科前沿设计成考核内容。介绍了"讲一练二考三"理念在有机化学实验教学改革中的运用。教学实践表明该教学模式能够提高学生的学习主动性,有利于培养创新思维和实践能力。 相似文献
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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. 相似文献
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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. 相似文献
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Scott RT Milios CJ Vinslava A Lifford D Parsons S Wernsdorfer W Christou G Brechin EK 《Dalton transactions (Cambridge, England : 2003)》2006,(26):3161-3163
[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". 相似文献
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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. 相似文献
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'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. 相似文献
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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. 相似文献
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Rodríguez JI Autschbach J Castillo-Alvarado FL Baltazar-Méndez MI 《The Journal of chemical physics》2011,135(3):034109
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. 相似文献
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