豫北地区化学"研究性学习"开展情况的调查与思考

研究性学习是一种学习方式，是中学课程改革后的必修内容，但是受“3 大综合”考试形式的影响，许多学校开展的情况却很不理想，本文通过调查建议学校领导正确把握教育方针，不要只关注升学率；老师转变教学思想，不要只盯着教学内容；并且在开展研究性学习时要制定合理的步骤，保证整个过程能够顺利进行。     

中学化学教学中实施研究性学习的尝试

研究性学习既是一门课程,更是一种方法。在开发研究性学习课程的同时,必须注重学科课程在教学形式和内容上向研究性学习的借鉴。本文就中学化学教学中如何实施研究性学习提出具体思路,探讨了中学化学教学中实施研究性学习 的方法、步骤。     

初中化学开展研究性学习的尝试

“研究性学习”既是一门课程,又是一种新的教与学的方式。主要从现行教科书中的研究性学习内容、研究性学习片断、化学实验中的研究性学习、化学习题中的研究性学习、化学复习中的研究性学习、化学课外研究性学习等方面介绍了在初级中学进行实践尝试的体会。     

关于网络环境下中学化学"研究性学习"

以网上中学化学信息资源的现状,探讨网络环境下实施中学化学研究性学习的可能性与途径,以互联网来缓解当前研究性学习资源匮乏和学校网络利用率低的矛盾.     

研究性学习的探索及实验

1　研究性学习的特点　　在研究生的学习和在国外考察时 ,我对联合国科教文组织教育丛书进行了系统的学习 ,了解了世界教育的发展方向和对人才的要求。我国基础教育必须以前瞻性、开放性的理念探索改革与实践 ,让研究性学习的教学模式逐渐成型。研究性学习是指学习者的主动探究、思索和建立知识体系的学习活动 ,是人们建立自身的认识事物和学习方法的主动的行为方式 ,是具有终身性的理念和策略。研究性学习是克服应试教育弊端的一种学习方式 ,她可以为培养学生的想象、创造、协调、开拓、严谨的研究问题的方法 ,使学生真正在研究问题的过程…     

本科有机化学的研讨式教学

研究性学习作为一种先进的教学理念已被广泛接受。将这种理念运用于教学实践时,要根据现有的教育实际,采用逐步过渡的教学策略,让学生参与探讨及研讨,才能有效发挥研究性学习的优势,使学生在认识活动中真正成为主体。开展研究性学习的教学策略设计时,要结合现有的传统教学方式和学生认知图式的实际情况,创设可以激发学生在认知活动中积极参与的情境,让学生在认识活动中建构个性化的知识图式。     

"化学专题"教学的合理实施

阐述了开展“专题教学”的意义以及如何将专题教学与课堂教学及研究性学习联系起来,并提出了可行性策略及在实施过程中应该注意的问题。     

研究性学习模式研究

本文以构建－试验－总结－升华为研究方法,探索了研究性学习模式：三原则重基础、三环节定主题、三阶段求发展,以及按此试验的“社团－研究－校本”化学研究性学习的立体模式。同时,还对该模式的具体操作和指导做出了详尽的探讨：该模式要求,基础教育阶段的研究性学习应该循序渐进,逐渐介入,既要避免学生对“研究”的简单认识,又要淡化学生对“研究”的神秘感;该研究模式提出并试验了现阶段研究性学习按照“前研究”、“研究”、“后研究”三步进行比较合理;该模式还试验探讨了在研究性学习模式中考虑其激励机制、发展机制。实施该模式能够体现研究性学习的可操作性,能够促进研究性学习实现其战略价值。     

关于研究性学习的点滴体会

随着素质教育的广泛开展和深入进行,研究性学习成为人们关注的热　点问题。“研究性学习”它所带来的绝不仅仅是一个学习方式改变的问题,而是关系到全体　学生健全人格的培养,关系到我们民族科学素养提高的大问题。国务院在关于基础教育改革　和发展的决定中明确指出：“教育是科教兴国的奠基工程,对提高中华民族素质、培养各级　各类人才、促进社会主义现代化建设,具有全局性、基础性、先导性作用。”开展“研究性　学习”是搞好基础教育的需要,是培养人的需要,是建设国家宏基伟业的需要。我们必须认　真对待,全力以赴,开展好研究…     

研究性学习与化学科课程教学整合研究

从“研究性学习课程整合化学科课程内容开发课程资源”和“化学学科开展研究性学习的方法与途径”两方面对研究性学习与化学科教学整合进行了研究与实践,提出了“开展研究性学习是提高学生能力的重要途径”和“研究性学习应以课堂教学为主阵地”的观点,取得了预期的研究成效。     

"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.     

“树脂-捕获-释放”技术在有机合成中的应用

“树脂-捕获-释放”技术使用功能化聚合物清除剂选择性地吸附目标产物,液 相组合合成小分子化合物库。这一技术结合了固相和液相的优点,操作简便、快捷 ,反应容易控制,产物易分离,且产率高,纯度好。     

材料科学中的点击化学

近年来,点击(click)化学反应以其高产率、高选择性以及对各种官能团和反应条件优异的耐受性成为材料科学家们手中有力的研究工具.本文综述了点击化学的概念、特点、反应机理及应用.重点介绍了点击化学反应在聚合物、表面修饰、纳米材料方面的研究进展,并分析了点击化学目前存在的不足及今后发展趋势.     

A "renaissance" in radical trifluoromethylation

This Minireview highlights recent developments in radical trifluoromethylation reactions. The trifluoromethyl group belongs to the privileged moieties in medicinal chemistry. Many drugs and drug candidates contain a trifluoromethyl substituent. Also in agrochemicals, the CF(3) moiety often appears. The present article addresses the radical trifluoromethylation of alkenes and arenes mainly focussing on recent achievements. However, important earlier work in this field is also covered.     

Switching "on" and "off" the expression of chirality in peptide rotaxanes

The hydrogen-bond-directed synthesis, X-ray crystal structures, and optical properties of the first chiral peptide rotaxanes are reported. Collectively these systems provide the first examples of single molecular species where the expression of chirality in the form of a circular dichroism (CD) response can selectively be switched "on" or "off", and its magnitude altered, through controlling the interactions between mechanically interlocked submolecular components. The switching is achievable both thermally and through changes in the nature of the environment. Peptido[2]rotaxanes consisting of an intrinsically achiral benzylic amide macrocycle locked onto various chiral dipeptide (Gly-L-Ala, Gly-L-Leu, Gly-L-Met, Gly-L-Phe, and Gly-L-Pro) threads exhibit strong (10-20k deg cm(2) dmol(-1)) negative induced CD (theta;) values in nonpolar solvents (e.g. CHCl(3)), where the intramolecular hydrogen bonding between thread and macrocycle is maximized. In polar solvents (e.g., MeOH), where the intercomponent hydrogen bonding is weakened, or switched off completely, the elliptical polarization falls close to zero in some cases and can even be switched to large positive values in others. Importantly, the mechanism of generating the switchable CD response in the chiral peptide rotaxanes is also determined: a combination of semiempirical calculations and geometrical modeling using the continuous chirality measure (CCM) shows that the chirality is transmitted from the amino acid asymmetric center on the thread via the macrocycle to the C-terminal stopper of the rotaxane. This understanding could have important implications for other areas where chiral transmission from one chemical entity to another underpins a physical or chemical response, such as the seeding of supertwisted nematic liquid crystalline phases or asymmetric synthesis.     

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.     

"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.