分析化学计量学

本文是《分析试验室》第五篇“分析化学计量学”专题定期评述文章。评述了１９９７年１月至１９９８年１２月我国分析化学计量学的主要进展。内容涉及统计学与统计方法、试验设计与优化、分析信号处理、多元校正、化学模式识别、定量构效关系（ＱＳＡＲ）、数据库及专家系统、化学计量学教学等方面,共引用文献１６８篇。     

化学计量学在电分析化学中的新进展

评述了化学计量学的各种方法,如主成分分析、偏最小二乘、小波分析、人工神经网络等在电分析化学中的进展,主要介绍了这些方法在电分析化学中的应用,并展望了化学计量学在电分析化学中的应用前景。     

分析化学计量学

本文是《分析试验室》第四篇“分析化学计量”专题定期评述文章，对我国分析化学计量学领域在１９９５年１月至１９９６年１２月间的研究工作进行了较为全面的概括和评述，内容涉及统计学与统计方法，试验设计与优化，多元校正，分析信号处理，化学模式识别，模拟与数据库及人工智能等方面，收入文献２４２篇。     

化学计量学在电分析化学中的应用

本文对化学计量学各种方法，诸如多元校正，因子分析，信号处理，参数估计，模式识别等电分析化学中的应用作了回顾及评述，指出了化学计量学电分析化学中应用的良好前景。     

分析化学取样理论研究进展

从化学计量学角度就分析化学的取样理论研究进行了系统总结。主要包括：取样误差与研究总体的理化性质间的关系;现代数理统计的理论和方法在分析取样中的应用;分析取样的质量控制。为深入研究并完善分析取样理论做了评述及展望。     

序言

国家自然科学基金委员会化学部于1993年4月5日至10日在长沙市湖南大学主持召开“分析化学计量学研讨会”,检阅基金委对化学计量学学科基金资助项目的研究进展和成果。应会议要求,本刊在本期特刊出“分析化学计量学论文”专栏,登载该资助学科的部分最新研究成果论文,并请国家自然科学基金委员会化学部分析与环境化学学科为专栏撰写了序言。相信这些论文的发表将对推动分析化学学科的基础理论建设和促进化学计量学这一新兴学科在我国的迅速发展起到良好的作用。     

1999年《分析试验室》定期评述预告

《分析试验室》每期设有定期评述栏目,对我国分析化学各个领域的发展进行两年一次的全面、系统的评述,单年份评述分析化学中各种分析技术的进展,双年份评述各种物料样品分析的进展。现将１９９９年各期的评述内容预告如下：发表期次题目撰稿人单位撰稿人第１期电化学分...     

电化学分析

本文是《分析试验室》定期评述中电化学分析第六篇评述文章。它评述了从１９９７年１月至１９９８年１０月期间我国电化学分析的进展。内容分基础理论与应用研究两大部分。前者包括电化学分析理论研究、电分析化学中的化学计量学方法,后者包括极谱与伏安法,络合吸附波与催化波,线性扫描伏安法,示差脉冲伏安法,吸附溶出分析法,示波分析法,微电极、超微电极与化学修饰电极,离子选择电极与各类传感器,光谱电化学,扫描隧道显微法和液／液界面电化学分析,电化学检测／电泳、色谱技术,电化学免疫法,电位分析法及其它等。共引用文献４８３篇。     

现代化学计量学进展

本文介绍化学计量学的概貌及其最近进展。化学计量学是最近十多年来发展起来的化学,主要是分析化学新兴分支学科。化学计量学的研究旨在统计学、数学及发现对分析化学有用的领域中改进分析方法和仪器。因此,现代化学计量学的进展,已使它成为分析测定过程中设计、控制、评价、验证等方面反映的中心。     

“分析化学计量学研讨会”会议简讯

1993年4月5日至10日在有“千年学府”之称的湖南大学嶽麓书院,由国家自然科学基金委员会化学部主持召开了“分析化学计量学研讨会”。应邀出席会议的有1989年至1992年以来,获得国家自然科学基金资助的分析化学计量学学科领域的重点项目和面上项目负责人:俞汝勤教授(学部委员)、卢佩章研究员(学     

丝素蛋白纤维及功能化材料的设计与构筑

随着环境污染、资源枯竭和医疗健康等问题的加剧,研发同时满足特定使用性能、安全性及可再生性的新型材料成为当前的发展趋势.而丝素蛋白材料正是以天然蚕丝为基本原材料,经一定的加工和功能化而形成的具有特殊结构、独特性能和广泛应用的生物质材料,近年来在生物医药、生物电子、智能传感等领域展现出巨大的应用潜力.本专论总结了丝素蛋白纤维及功能化材料的最新成果,结合本课题组相关工作,重点阐述了再生丝素蛋白纤维的仿生制备、生物医用支架的构筑与功能化、智能电子材料的设计以及天然多功能蚕丝及其构筑基元制备的研究进展,以期为高性能丝素蛋白材料的设计与构筑提供指导和借鉴.     

Recent developments in capillary and microchip electroseparations of peptides (2017–mid 2019)

The review presents a comprehensive survey of recent developments and applications of high performance capillary and microchip electroseparation methods (zone electrophoresis, isotachophoresis, isoelectric focusing, affinity electrophoresis, electrokinetic chromatography, and electrochromatography) for analysis, micropreparation, and physicochemical and biochemical characterization of peptides since 2017 up to about the middle of 2019. Progress in the study of electromigration properties of peptides and in the methodology of their analysis (sample preseparation, preconcentration and derivatization, adsorption suppression, EOF control, and detection) are described. Advances in CE and CEC methods are demonstrated and their applications in the following areas are presented: qualitative and quantitative analysis, determination in complex (bio)matrices, monitoring of chemical and enzymatical reactions and physical changes, amino acid, sequence and chiral analysis, and peptide mapping of proteins. In addition, micropreparative separations and determinations of important physicochemical characteristics of peptides by CE and CEC methods are reported.     

Epimerization and racemization of some chiral drugs in the presence of cyclodextrin and liposomes

The effects of alpha-, beta-, gamma- and dimethyl-beta-cyclodextrins (alpha-, beta-, gamma- and DM-beta-CyDs) and liposomes on epimerization or racemization of etoposide, ethiazide and carbenicillin were examined kinetically. alpha- and beta-CyDs accelerated both epimerization and hydrolysis of carbenicillin. They had no effect on epimerization of etoposide, and did not affect racemization and hydrolysis of ethiazide. DM-beta-CyD retarded epimerization of etoposide, hydrolysis of picroetoposide (which is an epimer of etoposide), and racemization and hydrolysis of ethiazide, but had no effect on epimerization and hydrolysis of carbenicillin. gamma-CyD retarded epimerization of etoposide and hydrolysis of picroetoposide. On the other hand, gamma-CyD accelerated epimerization of carbenicillin. It is suggested that the formation of inclusion complexes between CyDs and etoposide, picroetoposide and ethiazide inhibited the attack of bases such as OH- and buffer components, thereby retarding epimerization, racemization and hydrolysis. On the other hand, alpha-, beta- and gamma-CyDs increased the reactivity of carbenicillin through the OH group, accelerating its epimerization and hydrolysis. Liposomes retarded epimerization of etoposide, hydrolysis of picroetoposide and racemization of ethiazide. Liposomes did not affect epimerization and hydrolysis of carbenicillin. These differences in the effect of liposomes on reactivity may be interpreted in terms of the solubility of the drugs.     

Polymer-surfactant and protein-surfactant interactions

The phase behavior and some physicochemical properties of homopolymers (HP) and hydrophobically modified (HMP) polymers, as well as of polyelectrolytes (PE) and proteins (PR), in the presence of aqueous surfactants, or their mixtures, are discussed. Mixing the above components gives rise to the formation of organized phases, whose properties are controlled by polymer and/or surfactant content, temperature, pH, and ionic strength. Depending on the nature, concentration, and net charge of both solutes, molecular solutions, polymer-surfactant complexes, adsorption onto micelles and vesicles, gels, liquid crystalline phases, and precipitates are observed. Such rich polymorphic behavior is the result of a complex balance between electrostatic, excluded volume, van der Waals, and other contributions to overall system stability. It is also modulated by the molecular details and architecture of both the polymer and the surfactant. Different experimental methods allow investigation of the above systems and getting information on the nature of polymer-surfactant interactions (PSI). Surface adsorption and thermodynamic methods, together with investigation of the phase diagrams, give information on the forces controlling PSI and on the existence of different phases. Conductivity, QELS and viscosity allow estimating the size and shape of polymer-surfactant (protein-surfactant) complexes. Optical microscopy, cryo-TEM, AFM, NMR, fluorescence, and relaxation methods give more information on the above systems. Use of the above mixtures in controlling gelation, surface covering, preparing dielectric layers, and drug release is suggested.     

Recent advances in thin-layer chromatography of pesticides

Advances in the applications of thin-layer chromatography (TLC) and high-performance thin-layer chromatography (HPTLC) for the separation, detection, and qualitative and quantitative determination of pesticides, other agrochemicals, and related compounds are reviewed for the period 1998-2000. Analyses are covered for a variety of samples, such as food, biological, and environmental, and for residues of pesticides of various types, including insecticides, herbicides, and fungicides, belonging to different chemical classes. References on formulation analysis, hydrophobicity studies, and the use of TLC and thin-layer radiochromatography (TLRC) for studies of pesticide metabolism, degradation, uptake, and related studies are also included.     

科教融合视域下高分子材料专业综合实验教学探索与实践

基于科学技术的发展、时代的要求,教育改革势在必行,科教融合是发展的新趋势.《高分子材料综合实验》是高分子材料与工程专业的一门必修课,在学生从学校到工作岗位顺利过渡中起着重要的桥梁作用.科教融合在该门课的教学中显得尤为重要,能使学生综合能力、科学素养得到有效提升.以花生壳吸附剂的制备及其应用为例,介绍了科教融合的教学方法...     

Mononuclear,polynuclear, and cluster complexes of molybdenum and their reactions as models of biochemical systems and processes

Data on the composition, structure, and properties (electronic and geometric structure, optical properties, thermodynamic functions) of mononuclear, polynuclear, and cluster complexes of bi-, tri-, tetra-, penta-, and hexavalent molybdenum are summarized and correlated. The thermodynamics, kinetics, and mechanisms of the ligand exchange, protonation deprotonation, redox reactions, and formation decomposition of cluster cores of molybdenum complexes in aqueous solutions are characterized.     

Overall connectivities/topological complexities: a new powerful tool for QSPR/QSAR

Earlier attempts to assess the complexity of molecules are analyzed and summarized in a number of definitions of general and topological complexity. A concept which specifies topological complexity as overall connectivity, and generalizes the idea of molecular connectivities of Randic, Kier, and Hall, is presented. Two overall connectivity indices, TC and TC1, are defined as the connectivity (the sum of the vertex degrees) of all connected subgraphs in the molecular graph. The contributions to TC and TC1, which originate from all subgraphs having the same number of edges e, form two sets of eth-order overall connectivities, eTC and eTC1. The total number of subgraphs K is also analyzed as a complexity measure, and the vector of its eth-order components, eK, is examined as well. The TC, TC1, and K indices match very well the increase in molecular complexity with the increase in the number of atoms and, at a constant number of atoms, with the increased degree of branching and cyclicity of the molecular skeleton, as well as with the multiplicity of bonds and the presence of heteroatoms. The potential of the three sets of eth-order complexities for applications to QSPR was tested by the modeling of 10 alkane properties (boiling point, critical temperature, critical pressure, critical volume, molar volume, molecular refraction, heat of formation, heat of vaporization, heat of atomization, and surface tension), in parallel with Kier and Hall's molecular connectivity indices (k)chi. The topological complexity indices were shown to outperform molecular connectivity indices in 44 out of the 50 pairs of models compared, including all models with four and five parameters.