有机化合物系统命名中各种“基”的命名建议

主要讨论有机化合物命名中各种"基"在中文中的表达方式和使用。     

大学化学“原子结构”教学中几个问题的讨论

对大学化学课程"原子结构"教学内容中关于"自旋量子数"的定义、"为什么电子不会掉到原子核上"以及"原子轨道能计算"的规定中存在的问题,进行了讨论,并提出了新的教学建议。     

生物化学中酶促"不可逆"反应及其相关问题辨析

在生物化学教学和研究中,一些酶促反应被归类为不可逆反应。然而,此处的"不可逆"与物理化学中的"不可逆"有所不同,这一表述本身常导致学生的困惑。不仅如此,"不可逆"的实际含义及其衍生的观念可能进一步使学生产生很多对基本生化反应过程的严重误解。本文以物理化学所定义的"不可逆"为准,重新讨论生物化学中所指"不可逆"的准确含义,并举例讨论了包括"速控步""限速酶""高能磷酸键"在内的若干因生物化学中"不可逆"的不准确定义造成的认知误区。     

同素异形体与多晶型体

在化学教学中,特别是在讨论元素单质性质时,常常使用术语"同素异形体".然而不同的教科书对"同素异形体"下了不同的定义,即使同一作者对"同素异形体"也作了不同的解释.这样就使得"同素异形体"的概念变得模糊起来,更为重要的     

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。     

在分析化学实验教学中渗透"量"的概念

分析化学实验教学中存在的主要问题是学生对"量"的概念认识不清晰并且不重视。本文结合教学实践,提出了注重细节教学和数据的读、写、算,采用问题法以及讨论法等措施,在分析化学实验教学中渗透"量"的概念,使学生正确理解"量"的概念,在实验中能做到该细则细,该粗则粗。     

“镁条燃烧”实验在初中化学中的作用及实施

通过比较,分析"镁条燃烧"实验在不同版本的义务教育化学教科书中围绕核心知识所发挥的作用。重点对"镁条燃烧"实验在"质量守恒定律"学习过程中的适切性进行讨论,通过对反应原理的复杂性、实验结果的多样性、实验过程的危害性等方面的分析,提出了一些关于"镁条燃烧"实验操作的实施建议。     

无机化学教学中“课程思政”教育的探索与实践

结合无机化学特点,分析专业课教学中开展"课程思政"存在的问题,讨论如何挖掘无机化学课程所蕴含的思想政治教育元素,探索思想政治教育融入无机化学课程的实践途径,提出在专业课教学过程中,通过典型案例融入思政元素的具体方法,以实现价值引领、能力培养和知识传授的"三位一体"教育目标,培养德才兼备的高素质人才。     

更正：不同拓扑结构高分子链在拉伸流场下如何穿过柱状纳米小孔?

正致《高分子学报》编辑部:我们发表于《高分子学报》2014年第1期的文章"不同拓扑结构高分子链在拉伸流场下如何穿过柱状纳米小孔?"(作者:李连伟,金帆,何卫东,吴奇)需做出更正说明.在原文第4页关于"de Gennes基于能量平衡发展的高分子链过孔的经典理论"的讨论中,基于链珠流体力学能和受限自由能展开的具体讨论和推算过程仅适用于线形链,而原文中忽略了对星形和超支     

固体表面填隙H的化学活性起源于泡利排斥效应

各类固体表面常对外来原子(离子)施加泡利排斥作用.它明显改变了表面填隙或者替位原子(离子)的物理性质.我们首先说明泡利排斥作用广泛存在于各类固体表面.并引进"泡利穴"的概念,用来定量计算固体表面低凹处填隙位置上的外来原子在泡利排斥作用下性质的改变.重点讨论了多相催化中最重要的过渡金属表面的"泡利穴".然后简短介绍我们已经发表的工作,即泡利穴中H原子薛定谔方程的解析.进一步,将填隙H的基态波函数和基态能与自由H原子做比较,显示其性质的改变.由此详细论证,填隙H化学活性增加的两个关键的物理原因是,填隙H电离能的明显降低及诱导电矩的存在.我们把这种激活方式简称为"固体表面填隙H的泡利激活",并讨论它对加氢反应的贡献.同时,对近年来催化研究中一个令人困惑的实验结果给出我们自己的解释.实验明确表明,对加氢反应起关键作用的是过渡金属"表面下的H原子",它们在加氢反应中非常活跃.而"表面H原子"没有参与加氢反应.我们论证,过渡族金属"表面下的H原子"正是被泡利激活的填隙H.限于讨论多相催化问题(固体表面填隙H原子的催化).但是"泡利激活"原则上可以推广到均相催化中.因为在均相催化中经常使用的催化剂通常也具有类似的泡利穴结构.我们只讨论泡利穴中填隙H的催化,但是原则上不难推广到其他元素,例如用类似方法探讨石墨烯表面填隙锂原子的泡利激活.近来的天文观测中发现,很多有机分子云团中(例如H_2O, CH_4, C_2H_2, C_2H_4…等云团),同时存在一些尺寸约0.001～10μm的尘埃物质(如C颗粒, SiO_2颗粒等等).两者的并存使我们猜测,或许这些尘埃物质(包括纳米颗粒)本身就是多相催化剂,其表面存在的"泡利穴"可能对分子的形成有重要贡献.     

How mobile NMR can help with the conservation of paintings

The conservation of paintings is fundamental to ensure that future generations will have access to the ideas of the grand masters who created these art pieces. Many factors, such as humidity, temperature, light, and pollutants, pose a risk to the conservation of paintings. To help with painting conservation, it is essential to be able to noninvasively study how these factors affect paintings and to develop methods to investigate their effects on painting degradation. Hence, the use of mobile nuclear magnetic resonance (NMR) as a method of investigation of paintings is gaining increased attention in the world of Heritage Science. In this mini-review, we discuss how this method was used to better understand the stratigraphy of paintings and the effect different factors have on the painting integrity, to analyze the different cleaning techniques suitable for painting conservation, and to show how mobile NMR can be used to identify forgeries. It is also important to keep in mind its limitations and build upon this information to optimize it to extend its applicability to the study of paintings and other precious objects of cultural heritage.     

Highly effective and enantioselective Phospho-Aldol reaction of diphenyl phosphite with N-alkylated isatins catalyzed by quinine

Cinchona alkaloids were first successfully reported to promote enantioselective Phospho-Aldol reaction of diphenyl phosphite to a variety of N-alkylated isatin derivatives in good to excellent yields (up to 99%) and moderate to good enantioselectivities (up to 73% ee) almost in no time.     

NMR spectroscopic study of the Murex trunculus dyeing process

It is widely accepted that indigo dyes derived from Murex trunculus were used to produce the biblical dyes tekhelet and argaman. We describe a method of following the debromination of natural leucoindigos and their binding to wool using NMR spectroscopy. Debromination is observed prior to reaction with the wool and prior to oxidation. Binding to the wool is shown to occur prior to oxidation. NMR allows the dyeing process to be followed. This, in principle, could be used to correct problems during dyeing that would increase the reliability of the process.     

Designing for sustainability with biocatalytic and chemoenzymatic cascade processes

Cascade reactions have been widely recognized to cut costs, decrease solvent usage, and reduce cycle times in chemical processes. Recently, biocatalytic cascades have altered how we design synthetic routes to complex molecules to achieve sustainable commercial processes for pharmaceutical, agricultural, and fine chemical industries. With advancements in protein engineering and an increase in the number of enzyme classes available to chemists, industrial and academic groups alike have endeavored to expand the scope of biocatalysis from single reactions to multi-enzyme cascades to rapidly build complex molecular structures. Recent reports have drawn inspiration from biosynthetic pathways and have applied engineered enzymes to in vitro enzymatic cascades. Furthermore, combining transition-metal catalysis and enzymes in one-pot chemoenzymatic cascades likewise serves to broaden the scope of biocatalysis, enabling traditional chemical reactions to be performed under mild aqueous conditions. In this article, we review recent biocatalytic and chemoenzymatic cascades from 2019 to 2021.     

Modification of Cyclodextrins for Use as Artificial Enzymes

The magical powers of enzymes have been attributed to their ability to bind specific substrates and catalyze reactions of the bound substrate. Artificial enzymes synthetically mimic the binding and the catalytic site to produce molecules that are not only smaller in size but also potentially have similar activity to the real enzymes. The main objective of our research is to create artificial redox enzymes by using cyclodextrins as binding sites and attaching flavin derivatives as the catalytic site. We have developed a strategy to attach a catalytic site to cyclodextrin exclusively at the 2-, 3- or the 6-position. The evaluation of the artificial enzyme in which flavin is attached to the 2-position gives a 647-fold acceleration factor. Although this is modest compared to those of real enzymes (which can have acceleration factors of a trillion), the artificial enzymes allow us to understand the elements that contribute to the incredible catalytic power of enzymes.     

Defects,flexoelectricity and RF communications: the ZBD story

ABSTRACT

The zenithal bistable display (ZBD) was the first liquid crystal device mode to be commercialised that uses nematic disclinations in a constructive fashion, to use the flexoelectric effect inherent to all liquid crystals but at the time was considered too weak an effect to be useful, and to transfer nano-replication methods to the LCD manufacturing environment. The genesis of the invention and spin-out company ZBD Displays Limited will be described, and the evolution of that company from licensing model, through fabless manufacturer to display provider and finally to a system provider for the retail sector. The story may be useful not just to those interested in the science behind a rather unusual LCD, but also those involved in taking technology from laboratory to manufacturing, from idea to commercial success.     

Electrochemical approaches for the detection of amyloid-β, tau,and α-synuclein

According to the World Health Organization, there are 47 million people worldwide who are afflicted with dementia today, and this is expected to rise to 132 million by 2050. Therefore, it is pertinent to develop efficient analytical methods such as electrochemical biosensors to study these disorders and diagnose them early. This review highlights some of the recent key developments in the use of electrochemical biosensors to study the biomarkers related to neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Especially, we focus on the applications of electrochemistry to analyze amyloid-β and tau related to Alzheimer's disease and α-synuclein related to Parkinson's disease.     

增强无机化学教学的趣味性策略的案例研究

针对无机化学的理论知识学习的"枯燥",提出无机化学教学趣味性的三大增强策略,一是设定情境,让"枯燥"的知识生动起来;二是善用比喻,让"困难"的知识有趣起来;三是自创"小诗",让"复杂"的知识幽默起来。通过实践,三大增强策略的效果很好,值得广泛推广。     

Computational design of rasagiline derivatives: Searching for enhanced antioxidant capability

A set of new rasagiline derivatives is presented. They were designed to be antioxidant compounds with the potential to be used for treating neurodegenerative disorders. They are expected to be multifunctional molecules that can help reduce oxidative stress, which is thought to contribute to neurodegenerative disorders. The CADMA-Chem computational protocol was used to produce rasagiline derivatives and to evaluate their likeliness as oral drugs and antioxidants. Three of them were identified as the most promising ones. They are proposed to be better free radical scavengers than rasagiline. In addition, they are expected to keep the parent's molecule neuroprotective capability. Hopefully, the results presented here would promote further experimental and theoretical investigations on these compounds.     

Sol-Gel Fabrication of Rare-Earth Doped Photonic Components

The use of sol-gel to fabricate silica-on-silicon waveguides, and particularly erbium-doped waveguide amplifiers, is reviewed. In particular, efforts to use sol-gel to improve molecular homogeneity in heavily Er-doped silica-based films is discussed. A variety of material studies carried out to investigate the gain limitations found in these materials is then presented. These include x-ray diffraction, ellipsometry and Rutherford backscattering. Excess heat treatment is used to force crystallisation of the films, and analysis of the resulting structure is used to infer properties of the glass before the additional heating. The use of erbium alkoxide precursors is shown to alter the erbium environment in the final glass, in comparison to the use of inorganic erbium salts.