浅谈我区高校分析化学教学中多媒体的应用

根据我区大学生的实际情况，以及多年来在分析化学教学中的实践经验，通过分析传统教学与多媒体在分析化学教学中的应用，阐述了分析化学教学过程中应用多媒体的优势及需要注意的问题，提出了我区高校分析化学教学中利用多媒体教学与传统教学相结合的必要性。     

The analytical determination of friction for flow through conical converging dies

The effects of friction upon the intermediate and final distorted grids for wire drawing and/or extrusion were analytically studied for an assumed triangular velocity field. An upper-bound solution for the process was used. This solution predicted that the shape of the final and intermediate distorted grids were functions of the process geometry and of friction. Initially, combinations of reduction and semi-cone angle (α) were found for which the triangular velocity field was energetically preferred over an existing spherical velocity field. The analytical final distorted grids were then compared to experimentally obtained final distorted grids to determine the experimental friction. This was done by plotting calibration curves for distortion where friction served as the parameter and by comparing the actual distortion with the family of calibration curves.     

高职分析化学实验中基本操作常见错误解析

分析化学实验是高职实践教学的重要组成部分,对学生实验中基本操作的常见错误进行分析,为提高实验教学质量提供抓手,有利于学生专业素质的培养。     

水中总氮测定方法的经验总结

水中总氮的测定目前多数实验室采用碱性过硫酸钾消解紫外分光光度法(GB11894-89),该方法虽步骤少、成本低,但在测定过程中往往会出现空白值偏高问题,导致测量结果不够准确。作者根据多年工作经验,对该测定方法的实验条件提出一些改进,从而使该种测定方法的空白值达到要求。     

薏米人工湿地基质中总铬含量的测定

实验研究的目的是测定薏米人工湿地系统中基质中总铬的含量。采用硝酸-氢氟酸-高氯酸消解预处理土壤样品,再用火焰原子吸收分光光度法测定样品中总铬的含量。结果表明:随着不同浓度的处理,高浓度处理样品中总铬含量高于低浓度处理样品总铬含量.,而低浓度处理样中总铬含量降低的量及速率均高于高浓度处理样中总铬的含量。7月份样品中总铬的含量6月份样品中的含量5月份样品中的含量。     

The endeavor of total synthesis and its impact on chemistry,biology and medicine

The synthesis of urea in 1828 set in motion the discipline of organic synthesis in general and of total synthesis in particular, the art and science of synthesizing natural products, the molecules of living nature.Early endeavors in total synthesis had as their main objective the proof of structure of the target molecule.Later on, the primary goal became the demonstration of the power of synthesis to construct complex molecules through appropriately devised strategies, making the endeavor an achievement whose value was measured by its elegance and eiciency. While these objectives continue to be important, contemporary endeavors in total synthesis are increasingly focused on practical aspects, including method development,eiciency, and biological and medical relevance. In this article, the emergence and evolution of total synthesis to its present state is traced, selected total syntheses from the author's laboratories are highlighted,and projections for the future of the ield are discussed.     

分光光度法测定水中总磷含量结果不确定度评定

检测水中总磷含量及其不确定度的评定。按照国家标准GB11893—89水质总磷的测定,采用分光光度法测定水中总磷含量,根据JJF1059—1999《测量不确定度评定与表示》,对分光光度法测定水中总磷含量结果进行不确定度评定。同时测定了国家水质总磷的质控样(GSB07-3169-2014,批号:203964)标准值及扩展不确定度为:1.52±0.06mg/L,k=2。与实验室测定结果为:1.54mg/L,相符合。     

浅析硫铁矿中全铁含量的快速测定

硫铁矿被酸溶解后,用二氯化锡把三价铁还原为二价铁,多余的二氯化锡用氯化高汞氧化,以二苯胺磺酸钠为指示剂,用重铬酸钾标准溶液进行滴定。与国家标准方法进行比对,两者结果一致,且该法具有简便、快速、准确、成本低、稳定性好等优点,能够满足生产的需求。     

信息时代新形势下的大学教师角色认知探讨——以分析化学教学为例

信息技术的发展给高等教育带来了冲击,对大学教师的角色定位提出了新的要求。文章以大学本科的分析化学教学为例,通过分析信息时代新形势下师生关系的转变,提出了教师要由学习的主导者转变为学习的组织者和管理者,坚持让学生成为学习主体的教育理念,而强化教师的激励、启发、引导、监督功能。最后,探讨了在信息化时代如何充分发挥大学教师新的教学潜质,以适应新的教学需求。