“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。     

Teaching System Construction of Polymer Chemistry Experiment and its Function on Training Creative Applying Talents

高分子化学是材料化学专业重要的技术基础课,是一门以实验为基础的学科,因此,高分子化学实验是高分子科研和高分子教学的重要组成部分,是学生在掌握高分子化学的基础上,学习高分子合成的各种实验技术、聚合实施方法,培养学生进行高分子材料研究和技术开发的基本能力。从市场就业对高分子材料方向的人才需求出发,以培养创新性应用型人才为目标,通过开展实验技术讲座、改进基础性实验为综合性实验和设计性实验、增加研究性实验对高分子化学实验教学体系进行了改革,实验内容体现材料的应用性和工程价值,培养了学生的创新能力、工程实践能力。     

绿色化学理念在高分子化学实验教学中的渗透

绿色化学是促进人类与自然和谐发展的化学,培养绿色化学意识是实现社会可持续发展的基本要求。高分子化学实验是高等院校高分子材料专业或材料化学高分子方向本科生开设的一门必修课,对学生进行绿色化学教育具有非常有利的条件。文章分析了在高分子化学实验课程中开展绿色化学教育的必要性与可行性;介绍了高分子化学实验教学中开展绿色化学教育的具体措施。通过绿色化学理念在高分子化学实验教学中渗透,在提高学生动手能力的同时,又增强了学生的绿色化学意识。     

国家一流专业建设背景下“赛教融合”的高分子化学实验教学改革与实践

安徽建筑大学高分子材料与工程专业2021年获评国家级一流本科专业建设点,对本专业人才培养能力提出了更高的要求。高分子化学实验是高分子专业核心课程,是该专业重要的实践环节。全国大学生高分子材料实验实践大赛作为高分子领域的实验技能大赛,对学生多方面能力都进行了培养、锻炼与提升。课题组从引进合理竞争,与企业联合打造校内实验大赛、构建比赛与常规实验实践教学融合的课程体系以及细化实验过程考核+变革实验运行方式等三方面形成了“赛教融合”的高分子化学实验教学模式,以提升高分子化学实验教学效果,满足一流专业建设的要求。     

高分子化学实验教学中的自主科研创新引导——以“水凝胶的制备与性能研究”为例

在创新型人才的培养中,需要着力提升学生的探索精神、批判思维和实践能力,如何激发学生的科研志趣、提高创新能力是专业基础实验课程面临的挑战。高分子化学实验作为一门专业实验必修课,更应适应时代发展潮流与人才培养趋势,课程在夯实基础实验内容和基本原理的前提下,以更具吸引力的前沿性、应用性的实验背景为引导,通过内容编排,增加"自主研究"的教学模式,给予学生更加广阔的自由发挥空间,培养学生的创新能力和科研素养。经过多年的教学实践,我们以"水凝胶的制备与性能研究"为试点项目,进行了自主探索型立体式高分子化学实验课程体系的建设探索,将经典的溶液聚合实验,拓展为4个有应用背景的"科研工作坊",均取得了非常好的教学效果。我们相信,这种自主研究的实验教学方式,以及立足于培养学生创新能力的实验教学思路,将是未来高分子化学实验课程坚持并不断探索的方向。     

《高分子化学实验》课程的教学改革与学生实践能力培养

《高分子化学实验》课程是培养高分子专业人才的重要实践环节。本文就如何激发学生的学习兴趣和创造欲望、开设综合性实验项目、实验教学与科研相结合和改进实验考核方式等方面的措施,对《高分子化学实验》的教学内容和教学方法进行改革。旨在培养和提高学生的实践能力和创新能力,强化学生的综合素质和应用能力。     

“学以致用”的高分子化学实验改革——以“家用高分子防火凝胶”为例

传统高分子化学实验往往侧重于不同聚合机理及聚合方法的罗列,注重学生基本理论及基础实验技能的培养。教学过程中,以教师讲授以及学生根据特定实验步骤重复为主。笔者结合自身近5年本科生高分子化学实验的教学情况发现,在传统高分子化学实验过程中,学生缺乏主动性和能动性,实验结束并撰写完实验报告后很快会将相关实验遗忘,实验教学效果欠佳。思考如何将高分子科学相关知识与人们的日常生活密切联系到一起,增加学生的学习兴趣、实验趣味性及实际意义至关重要。本文以"高保水型家用高分子防火凝胶"为例,探索"学以致用"的现代高分子化学实验的可行性。结果表明,学生对该实验兴趣浓厚,实验结束后绝大多数同学感到自己可以综合应用高分子科学相关知识来解决实际问题,并能获得一定"成就感",实验教学效果良好。     

高分子化学实验教学的初步探索

主要从四个方面介绍了我校在高分子化学实验教学过程中所做的初步探索:第一,加强实验教学环节,对验证性实验进行改进,设法提高学生对于实验的兴趣和实验教学效果;第二,改革传统的高分子化学实验教学的模式和教学内容,将高分子化学、高分子物理和成型加工所学知识有机结合起来,开设综合性高分子实验课程;第三,紧密结合本校教师科研情况,开设研究创新性实验,并开设第二课程,鼓励学生利用课余时间参与教师的科研,以培养学生独立分析问题、解决问题的能力;第四,结合本校实际情况,适量开设微量、半微量实验。     

响应曲面试验设计在综合化学实验教学中的应用

论述了当前高分子化学实验教学现状,比较了几种试验设计方法,介绍了将响应曲面试验设计试验方法应用在高分子材料与工程专业综合化学实验的过程,并以聚苯硫醚(PPS)合成为例,讨论了如何确定影响试验结果的主要变量、变量的取值范围、如何建立拟合模型并对模型进行最终评价,从而确定实验最优条件。通过实验教学的开展,培养和训练了学生初步科学研究能力;提高了学生对实验数据进行有效的统计分析能力;培养学生创新性思维和团队合作精神。     

“微信群+翻转课堂”教学模式的学生高分子化学实验设计能力的培养

针对国内高校高分子化学实验设计能力培养存在的不足,将"微信群+翻转课堂"教学模式引入高分子化学实验教学,教师用微信将教学视频材料和学习资料课前群发给学生,将"课堂讲解"移至课前,调整高分子化学实验课堂内外的时间,有助于教师对学生进行高分子化学实验设计的训练,培养学生高分子化学实验设计能力。培养学生高分子化学实验设计能力的方法有:分类指导高分子化学实验设计,强化高分子化学实验设计方法,训练高分子化学实验设计步骤。     

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%.     

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.     

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.     

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.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.