促进学生认识发展的“电离和离子反应”专题的单元整体教学研究

系统梳理了电离、离子反应专题的已有研究,分析了电离、离子反应内容对学生认识发展的作用,进而确立了化学1模块电离、离子反应专题的教学论问题并进行了阐述分析。在上述研究的基础上,设计了化学1模块电离、离子反应专题的单元整体教学,并进行了教学实践,取得了较好的教学效果。     

分析化学实验课程教学大纲的标准化改造与构建

基于工程教育专业认证标准的要求,结合专业课程的特点,对我校制药工程专业的分析化学实验教学大纲进行了标准化改造。标准化的教学大纲更加突出了专业适用性,关联了教学要求与教学内容和考核评定,增加了考核量化指标与课程持续改进的方式,进一步规范了分析化学实验课程的教学。标准教学大纲的构建为实验教学活动提供了更加明确的指导,有利于缩小不同教师教学的差异性,保证了实验教学的质量,为建立可持续完善的工程类实验教学标准体系提供了具体参考。     

农科有机化学课程建设的探索与实践

对农科有机化学课程存在的一些普遍问题进行了分析;结合当前农林院校的特点,建立了符合农业院校特点的教学新体系;编制了一系列教材;建设了精品课程网站;建立了教学质量评价体系;建设了一支结构合理、教学水平高、团队精神好的教学队伍。     

新解色谱现象

在客观分析色谱现象的基础上对色谱分离机理的传统解释提出了质疑和否定,并对色谱分离机理作出了新的解释。通过对色谱现象的研究和分析,不仅确定了一条流体运动的基本规律,还对固定相赋予了新的内涵,提出了能量场固定相的设想。由于对色谱分离原理进行了新的解释,因此对色谱现象提出了一个新的定义。     

无机化学微信平台的构建与实践研究

针对无机化学传统教学模式的不足,构建了无机化学微信平台。介绍了构建平台必需的微信公众号和微信群的建立过程和方法。分析了无机化学微信平台在教学中的实践效果,弥补了传统教学中的不足。讨论了无机化学微信平台的积极作用,提高了教师教学水平和学生的学习能力,达到了师生双赢的目的。     

储氢合金电极的表面修饰研究

利用等离子体技术对AA型MH/Ni电池的储氢合金电极进行了镀覆导电膜层的表面修饰,用XRD及SEM对电极结构进行了表征.极片经过表面修饰的电池,其内阻降低了24％,放电容量有了明显提高,5C (7.5 A) 放电容量提高了200 mA•h,放电平台电压提高了约0.14 V,导电膜层还起到了电极保护层的作用,抑制了合金的粉化,提高了电池的循环稳定性.同时,电池内压显著降低,电池性能有了较大改善.     

左旋薄荷醇的合成现状及进展

阐述了左旋薄荷醇的理化性质及其应用现状和全球生产状况. 介绍了薄荷醇的合成思路、已经工业化的合成路线和一些有较高工业应用价值的路线, 并介绍了关于这些路线的最新研究进展. 最后对所介绍的路线进行了总结, 展望了其发展前景.     

木质素资源利用的研究进展

木质素作为一种大量存在的可再生资源,具有巨大的应用潜力。近年来,木质素资源的高效利用问题引起了人们的广泛关注。本文综述了近几年来国内外木质素资源利用的研究状况,简要介绍了木质素利用的两种方式:大分子形式利用以及液化降解利用。重点介绍了木质素液化降解制备生物油及酚类化合物的国内外研究现状,并对液化降解机理进行了阐述。最后,总结了当前木质素资源利用存在的问题,提出了未来木质素利用的研究方向,展望了木质素的发展前景。     

非理想气体的逸度因子和非理想溶液的活度系数

对单组分非理想气体,推导了它的逸度因子的微分方程式。对多组分非理想气体,推导了各组分逸度因子满足的微分方程式,定义了一个总逸度因子,并找到了总逸度因子和各组分逸度因子之间的关系。同样,对非理想溶液,推导了各组分活度系数满足的微分方程式,定义了非理想溶液的总活度系数,并找到了两者满足的关系。最后分析了逸度因子和活度系数之间的异同点。     

以培养创新型人才为目标的分析化学实验教学改革

在剖析传统化学实验教学弊病的基础上 ,提出并实施了分析化学实验教学改革的方案 ;通过更新教学内容 ,改革教学方式 ,增设开放实验 ,完善考核制度 ,加强了基础训练 ,突出了个性发展 ,培养了学生创新意识和创新能力 ;因材施教 ,促进了具有创新精神的高素质化学人才脱颖而出。     

Radiation effects on polymers—XII. Molecular weight and molecular weight distribution of cellulose acetate-grafted polyacrylamide side-chains and homopolyacrylamide using gel permeation chromatography

Calibration of gel permeation chromatography was carried out to determine molecular weight and molecular weight distribution of the side-chains and homopolymer formed during grafting of cellulose acetate with acrylamide monomer using accelerated electrons. Polyacrylamide in side-chains and in homopolymer was found to be of very high molecular weight; the grafting event was found to be as low as 1–10 polyacrylamide chains per 10³ cellulose acetate chains.     

驱油用聚丙烯酰胺分子量测试的光散射研究

利用旋转流变仪分析了超高分子量部分水解聚丙烯酰胺溶液的流变性质,并根据光散射动态模式分析了其在不同浓度和不同盐离子浓度下的尺寸分布.建立了利用多角度激光光散射准确测量驱油用超高分子量聚丙烯酰胺重均分子量(Mw)、均方根回转半径()和第二位力系数值(A2)的方法.准确测量了商品化驱油用超高分子量聚丙烯酰胺FP3630S的这3个参数,分别为Mw=(1.33±0.06)×107,     

Preparative isoelectric focusing of reduced wheat gluten proteins

Proteins extracted from gluten of the bread wheat cultivar Fiorello 2 in the presence of 2-mercaptoethanol or dithiothreitol were separated by isoelectric focusing in a free solution in a pH 3-10 gradient containing 50% v/v 1-propanol or urea. The collected fractions were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in 10% gels (high and medium molecular weight glutenin subunits) and 16% gels (low molecular weight gliadins). The isoelectric focusing pattern of gluten polypeptides in 50% v/v 1-propanol was comparable to that obtained on two-dimensional gel electrophoresis, based on isoelectric focusing and polyacrylamide gel electrophoresis or nonequilibrium pH gradient electrophoresis and polyacrylamide gel electrophoresis. A similar isoelectric focusing pattern was also observed when 3M urea was used as solvent. New gluten polypeptides, similar in mobility to the high molecular weight subunits of glutenin were detected at acidic pH.     

Effects of nonionic surfactant and associative thickener on the rheology of polyacrylamide in aqueous glycerol solutions

The effect of a low molecular weight nonionic surfactant and an acrylic associative thickener on the rheology of polyacrylamide in aqueous glycerol solutions under steady shear was experimentally investigated. The nonionic surfactant (Tween20), associative thickener (Acrysol TT935) and polyacrylamide (Separan AP30) underwent complex molecular interactions in solution as reflected by rheological measurements. The surfactant also interacted with the glycerol solvent. The addition of surfactant in aqueous glycerol solutions reduced the surface tension, as well as the solution viscosity, at low surfactant concentration. The solution viscosity went through a minimum at certain surfactant concentration, depending on the composition of glycerol/water mixture, before increasing again. Similar behavior was found when the surfactant was added to the polyacrylamide solution, except there was an initial increase in the viscosity before the reduction. The associative thickener, Acrysol TT935 (an anionic acrylic emulsion copolymer) exhibited a strong affinity with polyacrylamide in solution, as indicated by a sharp increase in the solution viscosity. The dilute polyacrylamide solution became highly elastic in the presence of either the nonionic surfactant on the associative thickener. A threestage model was proposed to describe the surfactant/thickener/polymer interactions.     

分散聚合法制备非离子型聚丙烯酰胺“水包水”乳液

利用丙烯酰胺在硫酸铵水溶液分散介质中的分散聚合制备了聚丙烯酰胺水溶性聚合物分散体;研究了硫酸铵浓度、聚甲基丙烯酰氧乙基三甲基氯化铵(PDMC)的相对分子质量及甲酸钠用量对聚丙烯酰胺水分散体系分散稳定性的影响.结果表明,获得稳定聚丙烯酰胺分散体系的最佳合成条件为:不加甲酸钠、PDMC的相对分子质量为8.02×105、硫酸铵的质量分数为20.9%.在最佳条件下得到的聚丙烯酰胺聚合物的相对分子质量为1.12×106.     

电子显微镜方法测定聚丙烯酰胺的分子量及分子量分布

用电子显微镜研究了聚丙烯酰胺的形态结构。将聚合物溶于正丙醇/水的混合溶剂中,用喷雾的方法制得单分子球粒,用电镜测定球柱尺寸,计算其数均,重均分子量及分子量分布。并讨论了沉淀剂/溶剂比例、溶液浓度及喷雾方法对所得结果的影响。     

Flocculation of kaolin particles by two typical polyelectrolytes: A comparative study on the kinetics and floc structures

The flocculation kinetics of kaolin particles induced by two polyelectrolytes is studied by using small-angle laser light scattering (SALLS). Two different methods, image analysis and SALLS, are used to calculated the fractal dimensions of flocs formed under different flocculation mechanisms. For a high charge density of polydiallyldimethylammonium chloride (PDADMAC), the initially flocculation rates are slow due to the quite low molecular weight. Smaller and more compact flocs are in the particle–particle connections, and restructuring of the flocs occurs in the flocculation process. With cationic polyacrylamide C498 of very high molecular weight and low charge density, however, the initially flocculation rates are much higher due to its rapid adsorption on kaolin particles, but it will take the adsorbed polymer a much longer time to reach equilibrium due to re-conformation. High potentialities of adsorption prevent the particles from entering the interior of the floc structure or rearrangement, which results in a more open floc structure. Different underlying flocculation mechanisms are evident for these two kinds of polyelectrolytes, in which charge neutralization is mainly involved for the low molecular weight and high charge density polymer of PDADMAC while polymer bridging is suggested to be the dominant mechanism for the high molecular weight polyelectrolyte of C498.     

In vitro release of protein from poly(butylcyanoacrylate) nanocapsules with an aqueous core

Factors influencing the in vitro release of bovine serum albumin (BSA) from poly(butylcyanoacrylate) (PBCA) nanocapsules, such as the pH value, BSA loading, the polymeric nanocapsule walls and protein molecular weight, were investigated in detail. The BSA release rate was affected by the degradation rate of the polymeric wall and protein loading. For low molecular weight proteins, the initial burst release was faster than that of high molecular weigh proteins and got to equilibrium quickly. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis results showed that BSA encapsulated within PBCA nanocapsules did not suffer covalent aggregation or fragmentation during the initial days of in vitro incubation. For nanocapsules prepared by interfacial polymerization in water-in-oil microemulsions, these findings were useful as a foundation for the development of nanocapsules with desired properties.     

聚丙烯酰胺/柠檬酸铝胶态分散凝胶性质的研究

用低浓度不同分子量的部分水解聚丙烯酰胺（ Ｈ Ｐ Ａ Ｍ） 和柠檬酸铝制备了胶态分散凝胶（ Ｃ Ｄ Ｇ） ,并用奥氏粘度计、超细粒度分析仪、岩芯流动实验对 Ｃ Ｄ Ｇ 的性质进行了研究．结果表明, Ｃ Ｄ Ｇ 的粘度比 Ｈ Ｐ Ａ Ｍ 粘度低,粒径在４５０ ～５２０ｎ ｍ 之间．岩芯流动实验结果表明, Ｃ Ｄ Ｇ 能够使岩芯的流动阻力大幅度增加,且在岩芯中达到同样的流动阻力所需通过 Ｃ Ｄ Ｇ 的体积与形成 Ｃ Ｄ Ｇ 的 Ｈ Ｐ Ａ Ｍ 的分子量、浓度及岩芯渗透率有关．     

Effect of cationic polyacrylamides on the interactions between cellulose fibers

The interaction between cellulose fibers in the presence of cationic polyacrylamide (CPAM) was analyzed by rheology as a function of polyelectrolyte concentration, charge density, and molecular weight. CPAM was found to strongly influence the yield stress of cellulose suspensions; low doses of CPAM increased the yield stress, but at higher concentrations the yield stress declined. The charge density of the CPAM was the most significant factor in how yield stress responded to CPAM concentration; this effect was able to be normalized to a master curve by considering only the charged fraction of the polymer. The molecular weight of CPAM samples had some effect at high concentrations, but for lower CPAM doses the yield stress was independent of molecular weight over the range studied. The data suggest that CPAM modifies the interaction between cellulose surfaces via several mechanisms, with electrostatic interactions in the form of charge neutralization and charged patch formation dominating; polymer bridging and steric repulsion also influence the overall balance of forces between interacting cellulose fibers.