安徽省农村初中化学实验教学现状的调查与思考

新课程将化学实验、科学探究作为化学课程改革的突破口,以培养学生的主动性和创新意识,提高学生的科学素养。自从新课程实施以来,农村中学化学实验教学情况如何,笔者通过对安徽省部分农村初中化学实验教学情况进行调查,探研问题存在的原因,并提出改进农村化学实验教学的几点建议。     

综合实践活动中培养学生化学科学素养的探讨

综合实践活动是新课程倡导的一种全新的课程形态,是新课程改革中的一个亮点,也是我国课程改革的一次结构性突破。科学素养是化学新课程标准所关注的重要方面,如何利用综合实践活动并在其实施过程中培养学生的科学素养是本文研究的核心内容。     

实施新课标新课程的新策略

为保证新课程教学目标的落实,需要把握好课程实施这个核心环节,课程实施的基本途径是教学活动。本文论述了为迎接新一轮高中课程改革、实施新课程需提前做好准备,教师需要通过校本教研,积累课程资源,研究教学策略,创造性地组织教学活动。     

实施新课程用好新教材

山东、广东、海南、宁夏4省区参加的普通高中课程改革实验工作已全面进入实施阶段。从前一段实施情况看,实验工作正顺利走向正常发展的轨道,但也使我们认识到高中实施新课程改革任务的艰巨性和复杂性,特别是多数教师对新课程改革精神认识不足,在使用新教材方面暴露出很多问题,主要有：一是教学观念落后,把陈旧的教学思想和传统的教学方法带入新课程;二是惟书是教,照本宣科,不敢越雷池一步;三是担心实施新课程改革会影响考试成绩,     

新课改前后学生选择化学专业动机的比较研究

新课程改革启动以来,实验区学校教育在诸多方面均有变化。对经历了新课程改革实验教学的部分大学生进行问卷调查,研究大学生选择化学专业或不选择化学专业的动机影响因素,与新课程改革前的动机影响因素进行对比,从中折射出化学新课程理念在实践中的落实情况,反映化学新课程实施中存在的问题。     

基础化学教育课程改革10年进展与反思(上)

1999年8月中国第8次基础教育课程改革全面启动,教育部成立初、高中化学课程标准研制组,开始研制课程标准,2001年教育部颁布《全日制义务教育化学课程标准(实验稿)》,38个地市成为首批国家级新课程实验区……至今,以新课程为代表的21世纪中国基础化学教育课程改革走进第10个年头。笔者亲身经历并全程参与了这一改革的过程,试图从新课程的课标设计形态、教材物化形态、教学实施形态和考试评价形态等角度较系统全面地回顾中学化学课程改革取得的进展,反思改革中的经验与问题,展望课程改革的发展方向。     

再谈更新基础教育课程改革理念问题

课程改革的核心是更新课程理念。结合基础教育新一轮课程实施中遭遇的诸多困惑,就面对现实、教师的天职与课程标准修订等事项对更新课程理念问题进行了一些探讨,提出了某些建议。     

2005年"理解和实施高中化学新课程"专刊(增刊)

在高中新课程进人实验区实施一年的重要时刻,《化学教育》编辑部本着对基础教育课程改革和高中化学新课程的高度关注与崇高的责任心,于2005年8月编辑出版专刊,以集中反映和报道实验区一线教师实施新课程、试教新教材、探索新教法的实践总结。     

《高中化学新课程教学论》体系构建与内容创新

以基础教育新课程改革的理念为依据,《高中化学新课程教学论》在教材体系的构建和教材内容的选择方面进行了大胆探索和创新,重视课程与教学的整合,全面提升师范生实施新课程的能力。     

希望与期待——2005年“理解和实施高中化学新课程”专刊(增刊)编后记

在高中新课程进入实验区实施一年的重要时刻,我刊本着对基础教育课程改革和高中化学新课程的高度关注与崇高的责任心,从2005年第1期起开辟了“新课程天地”栏目,同时又编辑出版了本期理解和实施高中化学新课程专刊(2005年增刊),以集中反映和报道实验区一线教师实施新课程、试教新教材、探索新教法的实践总结。在短短的一年时间里,高中化学新课程已取得了很大的进展:教材从必修到选修已全部出齐,实验区正从困难重重到逐步理清思路再到形成各具特色的行动方案;一线教师已经从茫然不知所措到逐步适应再到积极探索;关于新课程、新教材和实验教学…     

微乳及其应用

微乳在生物技术、人造血管、酶固定化、能源科学、纳米材料、涂料、医药、食品、石油、选矿、环境等方面得到了越来越广泛的关注和应用。对微乳的理论研究、组成、制备方法、性质表征及应用的研究作了阐述。微乳技术具有很好的发展前景。     

Microemulsion based chromatographic techniques: Past lessons and future directions

Microemulsion Liquid Chromatography (MELC) and Microemulsion Electrokinetic Chromatography (MEEKC) respectively have emerged as new forms of analytical techniques for the separation of drugs of different water solubilities, solving different separation challenges and offer a variety of applications in pharmaceutical industry and routine quality control analysis of drugs. A comprehensive review of the literatures on recent developments in the field of Microemulsion based techniques was made. Various literatures dealing with microemulsion based chromatographic techniques were collected and studied extensively. Major findings of all the important literatures were summarized and classified in an appropriate manner to help reader understand the types, methods and applications of the technique. This article covers basic concepts of microemulsion, their optimization parameters, advantages and disadvantages and a plethora of applications and research done over the last decade. Almost all the major researches done in the field were tried to cover. Microemulsion based chromatographic techniques have been proved to be a newer and interesting technique that is extensively studied nowadays. Due to their polyphasic structure, microemulsion as eluent in both MELC and MEEKC offers a large number of advantages, applications and capability in separating the mixture of components.     

Preparation of ultrafine high density gamma ferric oxide using aerosol OT microemulsions and its characterization

Ultrafine gamma ferric oxide has been prepared by controlled heating of ferrous oxalate at a temperature range of 225° to 300°C in moist air. Ferrous oxalate was prepared both in aqueous as well as in Aerosol OT microemulsion systems. It has been observed that the product is always a mixture of alpha and gamma ferric oxides which were characterized by TGA, DTA and XRD studies. Microemulsion mediated ferrous oxalate was found to yield more gamma ferric oxide than that from ferrous oxalate prepared in aqueous solution. However, the yield of gamma ferric oxide prepared through microemulsion mediated system depends on the size of the microemulsion droplets in which precursors have been participated as well as calcination temperature.     

Recent advances in the development and application of microemulsion EKC

Microemulsion EKC (MEEKC) is an electrodriven separation technique. Separations are typically achieved using oil-in-water microemulsions, which are composed of nanometre-sized oil droplets suspended in an aqueous buffer. The droplets are stabilised by a surfactant and a cosurfactant. The novel use of water-in-oil microemulsions has also been investigated. This review summarises the advances in the development of MEEKC separations and also the different areas of application including determination of log P values, pharmaceutical applications, chiral analysis, natural products and bioanalytical separations and the use of new methods such as multiplexed MEEKC and high speed MEEKC. Recent applications (2004-2006) are tabulated for each area with microemulsion composition details.     

Encapsulation of Hematite in Zircon by Microemulsion and Sol-Gel Methods

Microemulsion method has been applied and compared with sol-gel, coprecipitation and ceramic route with the purpose of encapsulating hematite into zircon crystals used as ceramic pigment. In the commercial synthesis of pink coral pigment, NaF flux agent is usually added in order to improve the reactivity of the system; therefore, the addition of flux agents (NaF or NaF · 2NaCl) has been investigated. Likewise, the effect of precipitating agent (NH₃ or NaOH) has been studied. Sol-gel becomes the more reactive method and produces the best red colours without fluorides addition, but does not give red colour in the presence of halides fired at 1000°C. Ammonia microemulsioned and coprecipitated powders give similar orange-brown colours without fluorides, and red colours with fluorides addition. The addition of NaF produces higher inclusion effectiveness than NaF · 2NaCl. The stabilization of sodium silicozirconate crystalline phases in NaOH coprecipitated or emulsioned samples avoids the zircon crystallization and then the hematite encapsulation.     

苯乙烯微乳液种子聚合

通过观测苯乙烯微乳液种子聚合前后体系内聚合物粒子大小及其分布的变化发现,无论是γ射线还是KPS引发,聚合过程中都没有新的聚合物粒子生成。尽管聚合前体系中存在单体溶胀的胶束,但在聚合过程中这些胶束主要充当单体仓库,自己成核聚合的几率很低。由于微乳液种子聚合体系内,单体量相对较低,聚合物粒子数目很大,其聚合动力学明显不同于常规乳液种子聚合。     

Application of MELC and MEEKC for the Analysis of Paracetamol and Related Impurities in Suppositories

Rapid MELC and MEEKC methods were developed for paracetamol suppository assay. MELC methods for paracetamol analysis and for separation of paracetamol and its impurities were previously reported. In this study, further development of MEEKC methods and a MELC method using anionic and cationic microemulsions gave excellent validation results for paracetamol content in suppositories. SDS Microemulsion instability resulted in poor reproducibility for impurity separations using gradient elution. A novel isocratic CTAB MELC method achieved reproducible separation of paracetamol and its impurities at 0.1% levels. MEEKC methods using SDS and CTAB microemulsions resolved all of the impurities however detection at 0.1% levels was not possible. These methods gave significant benefits in terms of reduced sample pre-treatment requirements. CTAB microemulsions had greater solubilising power than their SDS equivalent and were more stable due to their longer alkyl chain length.     

Separation of Hydrophobic Neutral Compounds by Microemulsion Electrokinetic Chromatography

Electrokineticchromatography(EKC)istheonlymodeofcapillaryelectrophoresisfOrtheseparationofelectricalneutralcompounds.Theseparationprincipleisbasedonthedifferentpartitionofsolutesbetweenthepseudostationaryphaseandthesurroundingaqueousphase.MicellarEKC(MEKC)provideshighspeedandhighefficiencyseparationforneutralcompoundswithsignificantsolubilityinaqueoussystem'.Theseparationofhydrophobiccompounds,however,givessomeproblems,becauseoftheirpoorsolubilityinaqueousphase.Inourpreviouswork"',somepol…     

微乳液毛细管电动色谱应用进展

微乳液毛细管电动色谱（MEEKC）是在胶束电动色谱基础上发展起来的一种电动色谱新技术。近几年来,MEEKC在各个领域的应用又有了长足的进步,尤其是在维生素、药物、天然产物、手性分离、生物分子、环境分析,以及药物疏水性评价上呈现出强势的发展,本文针对这些领域的MEEKC方法进行了评述。     

Recent advances in microemulsion electrokinetic chromatography

Microemulsion electrokinetic chromatography (MEEKC) is an electrodriven separation technique. Separations are typically achieved using oil-in-water microemulsions, which are composed of nanometre-sized droplets of oil suspended in aqueous buffer. The oil droplets are coated in surfactant molecules and the system is stabilised by the addition of a short-chain alcohol cosurfactant. The novel use of water-in-oil microemulsions for MEEKC separations has also been investigated recently. This report summarises the different microemulsion types and compositions used to-date and their applications with a focus on recent papers (2002-2004). The effects of key operating variables (pH, surfactant, cosurfactant, oil phase, buffer, additives, temperature, organic modifier) and methodology techniques are described.