从学科融合的角度构建结构化的教学内容*——以“自然资源的开发利用”为例

教学内容的结构化是促进学生从化学学科知识向化学学科核心素养转化的关键措施。自然资源的开发利用以地球的圈层结构为纽带,让学生在问题驱动下,通过阅读、分析教材等活动,逐次学习关于岩石圈、水圈中蕴藏的部分资源开发利用的问题,最后以地球为原点,畅想未来资源的探寻之路。使地理学科知识自然地融合在化学教学中,拓宽学生视野,实现学科间的融合。     

高中化学“自然资源开发利用”的项目式教学——生物质橘皮果胶的提取及工艺流程设计

以“生物质橘皮果胶的提取及工艺流程设计”为主题,聚焦“生物质资源利用”社会热点问题,围绕有机化学、实验化学、工艺流程等高中化学重点知识开展项目式教学。引导学生完成有机物结构与性质探析、实验设计与优化、果胶提取及工艺流程设计等活动,深化对“结构决定性质”的理解,形成物质分离提纯的一般思路,构建工艺流程思维模型,体会生物质资源利用的途径和意义,提升其化学学科核心素养及问题解决能力。     

融入地方特色资源的中学化学教学设计*——以“甘蔗的综合利用”为例

以广西蔗糖产业的现状为背景,围绕其特色经济作物甘蔗的综合利用为情境线,设计若干个关键性问题,引导学生从工业生产和生活实际的角度进行思考,学会从糖类物质的结构与性质的层面分析与解释,为国内蔗糖业的健康发展提出解决方案。培养学生解决综合问题的能力,进一步认识化学与生产、生活的关系,感受化学学科在社会发展中的价值。     

木质素β-O-4单元的光化学和电化学降解:醚键断裂反应的一种应用*

醚键断裂反应既是有机化学的重要教学内容,又在现实世界中具有广泛应用。木质素是一类重要的生物质资源,其降解核心为碳-氧键断裂反应体系,具有重要的研究价值。对木质素β-O-4单元利用光化学和电化学降解的最新科研进展进行总结,可为醚键断裂反应的教学提供应用案例,拓展学生科学视野。     

生物质利用新途径:多元醇催化合成可再生燃料和化学品

日益严重的全球性能源和环境问题促使开发利用可再生的生物质资源成为当前研究的一个热点。本文概述了生物质基多元醇合成燃料和化学品来实现生物质转化利用的一些最新进展,特别是集中介绍了甘油和山梨醇等多元醇催化水相重整合成氢气和液体烃等燃料、催化选择氢解和氧化合成高附加值化学品或化学中间体等方面的进展,分析了存在的问题和可能的解决措施以及今后的发展趋势,指出生物质基多元醇将成为今后合成可再生燃料和化学品的新型平台分子。     

引入前沿科学 培养化学核心素养——以“碳量子点的制备”综合实验设计为例

为培养化学核心素养,让中学生了解前沿科学领域明星材料纳米材料的性质和用途,设计开发了一个基于中学生认知水平的研究型综合实验--碳量子点的制备。以含碳量丰富的生物质材料为原料,通过碳化反应以及多次过滤处理方法制备了一种新型的碳量子点,克服了碳量子点制备所需的高温高压等条件限制,使碳量子点这一新型纳米材料的制备能够在中学化学实验中得以实现,利用荧光灯对碳量子点的荧光性质进行定性表征,并将碳量子点制作成隐形荧光墨水,增加了实验的趣味性和实用性。学生实验证明该综合实验适用于中学化学实验教学和实验能力培养,有助于培养学生的科学探究精神、创新意识和社会责任感。     

生物质利用新途径:多元醇催化合成可再生燃料和化学品

日益严重的全球性能源和环境问题促使开发利用可再生的生物质资源成为当前研究的一个热点.本文概述了生物质基多元醇合成燃料和化学品来实现生物质转化利用的一些最新进展,特别是集中介绍了甘油和山梨醇等多元醇催化水相重整合成氢气和液体烃等燃料、催化选择氢解和氧化合成高附加值化学品或化学中间体等方面的进展,分析了存在的问题和可能的解决措施以及今后的发展趋势,指出生物质基多元醇将成为今后合成可再生燃料和化学品的新型平台分子.     

生物质利用新途径:多元醇催化合成可再生燃料和化学品

日益严重的全球性能源和环境问题促使开发利用可再生的生物质资源成为当前研究的一个热点.本文概述了生物质基多元醇合成燃料和化学品来实现生物质转化利用的一些最新进展,特别是集中介绍了甘油和山梨醇等多元醇催化水相重整合成氢气和液体烃等燃料、催化选择氢解和氧化合成高附加值化学品或化学中间体等方面的进展,分析了存在的问题和可能的解决措施以及今后的发展趋势,指出生物质基多元醇将成为今后合成可再生燃料和化学品的新型平台分子.     

钠离子电池用生物质基硬碳的研究进展

生物质基硬碳具有原材料资源丰富、可持续、成本低和储钠容量高等特点,是钠离子电池的理想负极材料。生物质基硬碳材料的微结构是决定钠离子存储性能的关键。本综述回顾了硬碳负极对钠离子存储机理的研究现状。从生物质原料的角度,分类总结了高性能生物质基硬碳材料的制备方法。探讨了生物质基硬碳结构的调控与钠离子存储性能提升的关系,对钠离子电池用生物质基硬碳负极材料的研究方向进行了展望。     

“纤维化学与物理”课程混合教学模式的探索*

针对线上教学过程中师生面对面交流弱化,学生容易出现注意力不集中、知识点难以形象化等问题,遵从以学生为主、产出导向的教学理念,依托自建MOOC平台资源,打造“课前自学-线上教学-课后复习巩固”的三阶段混合教学模式。综合利用多种教学手段、资源,尝试翻转课堂,经过不断教学改革和实践达成教学目标,实现线上与线下教学质量的实质等效。学习成效在教学目标达成度、学生问卷调查和师生互动程度等3个方面得以体现,结果表明这种教学模式使得线上教学生动有趣,提高了学生学习积极性和注意力。     

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.     

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.     

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.     

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.     

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.     

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.     

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.