吉林大学化学学院构建“三阶式”教师教学能力发展体系*

吉林大学化学学院注重教师队伍建设,尊重教育规律,在发挥老教师“传帮带”作用的同时,结合时代发展,构建了科学合理高效的“三阶式”教师教学能力发展体系。在培养强化青年教师教学基本功的同时,注重全体教师新型能力的培养,搭建平台促进教师不断钻研教学内容,研究教学方式和方法,将专业知识与先进信息技术和教育教法融合,提高教学能力与水平,实现从“能教书”到“教好书”到“会教书”能力逐步提升的态势。该模式可为探索高校教师教学能力发展体系的建设提供参考和借鉴。     

美国高中化学教材以及化学教学特点

通过对美国著名的Saint John's Preparatory High School(圣约翰预备高中)和Apollo High School(阿波罗高中)化学教学实地听课与调查发现,美国高中化学教材以及化学教学有其鲜明的特点。美国高中化学教材有2/3是化学理论知识,1/3是化学应用性知识,教材内容紧密结合学科前沿技术与应用。美国高中化学教学的特点是:注重让学生用自己的方法解决问题,建构证据;知识的讲授注重强调知识之间的理解与联系,适当教授相关的学习策略;教学注重直观与模型建构等。     

基于项目式学习的高三化学实验和工艺流程专题复习*——以“海带中碘的提取”为例

以“海带中碘的提取”为例,提供文献让学生课前阅读,完成“海带中碘的提取”流程设计,并进行成果交流。在此基础上,进行方案实施,并进行总结评价。研究结果认为,将知识与实践结合,能够激发学生探究热情;将自主文献研究、方案设计、实验验证结合,可以培养学生的科学探究和创新能力;应该注重教-学-评一致性;需要进一步提高教师的实验实际操作能力和知识引导能力。     

高中化学教科书中科学素养主题的定量分析

运用内容分析法对高中化学新、旧教科书中的科学素养主题进行分析,得出科学素养主题内容发生了较大的变化;传统高中化学教科书的编写注重知识与技能,对科学过程与方法的关注不够;新高中化学教科书的编写突出了科学过程与方法,拓展了科学、技术与社会的相互关系。     

化学与环境试题精选

环境污染给人们造成的危害很大,环境保护问题已经引起人们的足够重视。近年的中考化学试题以及竞赛题;常结合空气与水等的污染和防污,注重对环境教育内容的渗透。现将有关这方面的试题精选如下。     

基于学科理解的学习任务设计策略

基于学科理解的学习任务是精细化教学研究的切入点,是核心素养的落脚点。基于分析学习任务的内容、方法、情境要素,结合原电池教学案例,提出以下设计策略:对教学内容本原性、结构化地理解;分析学生认知基础和学习困难,确定学习任务着力点;任务以本原问题体现,显化认识视角;注重学习任务的教学逻辑;活动指向学生的素养发展;创造真实适切的任务情境。     

百年诺贝尔化学奖研究成果嬗变对我国化学教学的启示

以本体论、认识论、方法论作为划分依据,将诺贝尔化学奖的研究成果划分为理论建构、物质研究、反应机理、发现与合成新物质、创造新方法5个部分。统计、分析百年诺贝尔化学奖研究成果的嬗变,得出对我国化学教学的有益启示：注重在理论学习的过程中培养学生的批判意识与创新精神;在知识学习的过程中突出化学的学科价值与社会价值;注重化学学科与相关学科的交叉整合。     

提高学生兴趣的有机化学教学法

介绍提高学生兴趣的有机化学教学法。主要方法包括注重绪论课教学,注重理论联系实际,注重把有机知识与人文教育相结合,注重学生学习能力的培养等。     

聚合物流变学教学中的几点体会

针对聚合物流变学多学科交叉性以及较强的理论性和实践性的特点,结合作者的教学实践,总结了在聚合物流变学教学中的几点体会。提出在该门功课讲授过程中注重教学内容与教学方法的形象化,培养学生的学习兴趣;通过开设实验课,放映实践过程录像、图片等形式将理论与实践结合的教学方法,消除学生学习该门课程的抽象感。此外,通过教学实例提出在...     

基于融合的无机及分析化学课程研究与实践

从融合的角度探讨了无机及分析化学课程的建设。融合分别体现在教师队伍、课程内容、教学模式、评价方式四个方面。在教师队伍建设上通过交往的方式优化完善教师知识结构;课程内容上以分支课程在较深入层次上的融会贯通为主线形成高水平的综合课程;在教学模式上通过翻转课堂与传统课堂的融合落实学生的主体地位;评价方式注重过程与结果的结合。     

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%.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

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.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

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.