以能力为导向的近化学类专业实验教学体系建设与实践

以提高学生能力为导向,对近化学类专业实验教学体系进行改革与实践.以“教-学-研”一体化建设为主线、虚拟实验室和开放实验室的建设为抓手、课内外教学结合为手段,分层次、多模块构建了“一主线、两结合、三层次”的实验教学体系.突出理论应用、技能训练与创新能力培养,对实验教学进行教学模式与教学方法改革探索,丰富了实验内容和组织形式,将专业知识、实践技能、综合素养的训练有机结合,更好地体现了重基础、强应用的人才培养目标,初步建立了具有鲜明人才培养特色的实验教学体系.     

农科基础化学实验研究性教学模式的构建与实践

针对农林高校化学实验教学中存在的问题, 提出以培养学生自主学习和创新能力为教学目标, 通过优化教学内容、改革教学方法, 提高学生学习兴趣, 形成了基础实验、综合设计性实验、研究性实验和创新实验等多层次实验教学体系, 构建了农科基础化学实验研究性教学模式。这对于提高学生的学习效率, 培养学生的自主学习能力与创新能力具有重要意义。     

基于PBL模式的化学实验设计与实施——以光催化降解染料脱色实验为例

以染料废水的降解脱色实验为例,探讨了PBL模式在化学实验教学中的应用,提出了基于PBL模式的化学实验教学运行程序及教学评价。在实验教学中,基于PBL的模式,以解决问题为任务驱动,发挥问题对学习过程的指导作用,鼓励学生积极参与教学过程,调动了学生学习的主动性和积极性,提高了学生掌握知识并应用于实践的能力,培养了学生的创造精神和创新能力。     

基于云班课的物理化学开放性实验教学实践*

以云班课为教学平台,采用翻转课堂为主的教学模式开展物理化学开放性实验教学,详细介绍了开放性实验分层教学体系、实验教学内容、微课的设计方法和实践过程。实践结果表明,通过这些教学手段,教师能顺利地开展开放性实验教学,提升学生的学习兴趣和创新能力,同时也提高了实验室资源的利用率。     

“以学生为中心”的高分子化学实验教学改革与探索

高分子化学实验是高分子材料与工程专业本科生的专业必修课程,是培养学生实践能力和创新能力的关键环节。针对高分子化学实验教学过程中存在的问题,从“以学生为中心”的教学理念出发,围绕优化实验教学内容、革新实验教学方法、健全实验评价制度等进行改革,从而锻炼和培养学生的创新能力和解决复杂工程问题的实践能力,全面提升学生的综合素质,满足社会对高素质综合型人才的需求。     

有机化学实验教学资源的建设与实践

教学资源建设是高校教学改革的一项重要工作。以提高实验教学质量和培养创新能力为目标,探索了我校有机化学实验教学资源的建设内容,并通过网络平台用于辅助教学。视频资源,有效地提高了课前预习效果;课件资源,培养了学生的实验设计思想和创新能力;拓展资源,开拓了学生的视野,提高了化学实验兴趣;在线测试题库资源,有效准确地检验了学生的理论水平。教学资源通过实践应用,教学效果明显,切实提高了教学质量。     

在实验教学中培养创新能力的尝试

在实验教学中通过开放式教学、研究式学习,探索新问题、设计新实验,以激发学生的学习兴趣,培养创新能力。     

分析化学实验教学改革探索

针对分析化学实验教学中教学内容设置不当,教学模式"保姆式",教学方法单一等问题,通过改变教学理念、构建新型实验教学体系以及改革实验教学方法等多种措施,提升了学生的实验兴趣,培养了学生的工作责任心和探索精神,提高了学生的应用创新能力。     

高师“化学教学论实验”教学变革研究

基于师范生专业能力提升和"化学教学论实验"教学存在对学生实验研究能力、创新能力和教学能力培养不足的现状,实施教学变革研究。通过开展以疑难实验为主题的研究性设计和实验教学活动,提升学生教学研究意识和能力,并在实践中全面提升师范生专业能力。     

基于“学习金字塔理论”的物理化学实验教学模式改革实践

介绍了东北林业大学物理化学实验课程教学中基于"学习金字塔理论"进行教学模式改革实践的情况。在实施实验教学过程中,通过增加"学生通过在线实验视频预习""学生为学生讲解实验""操作前学生小组讨论"和"操作后学生小组总结讨论"等学习环节,建立了一种有效的"以学生为中心"的实验教学模式,促进了学生综合素质和创新能力的培养,取得了良好的教学效果。     

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.