常态化疫情防控下的仪器分析实验教学实践的探讨

结合仪器分析实验的特点和教学中存在的问题,阐述了虚拟仿真技术应用于仪器分析实验教学对线下实验的补充作用,并介绍了虚拟仿真实验教学在应对"停课不停学"等特殊状况的出色表现,通过问卷和互动反馈,准确评估学生的学习状况,指出虚拟仿真实验的局限性,提出线上虚拟仿真与线下课堂实验相结合的教学模式,促进仪器分析实验教学质量的提升。     

氢氧化钠标准溶液浓度不确定度的评定

评定了按照GB／T601-2002方法配制和标定氢氧化钠标准溶液浓度的不确定度。从仪器、试剂、操作及实验环境方面分析了不确定度来源,对不确定度分量进行了分析、计算、合成。氢氧化钠标准溶液浓度的不确定度主要由标定时消耗体积的读数误差产生。在试剂纯度、仪器精度符合规定时,氢氧化钠标准溶液浓度的相对扩展不确定度为0．14％。     

C18反相色谱固定相的制备及性能评价——介绍一个仪器分析拓展性实验

介绍了一个本科生仪器分析拓展性实验——C_(18)反相色谱固定相的制备及性能评价。实验内容包含色谱固定相的合成、表征、装填及其性能评价,实验过程涵盖了有机合成、物理化学和仪器分析知识。通过本实验的实践,拓展了经典仪器分析实验内容,有利于培养学生综合运用知识的能力和科研探究能力。     

高校青年教师参与实验室大型精密仪器管理制度初探

青年教师是高校教学科研的主要力量,贵重精密仪器对于促进他们工作能力的提升尤其重要.在一些高校科研实验室,由于仪器多、专职实验技术人员少,造成仪器使用指导不及时、管理不到位、仪器利用率不高等问题.为了充分发挥贵重精密仪器在培养青年教师科研水平中的作用,创新仪器管理办法,建立"贵重精密仪器认领制".制度的实施,充分调动青年教师开发仪器的积极性,在提升青年教师科研水平的同时,增强了专职实验技术人员实验技能,同时提高了贵重精密仪器的利用率.     

仪器分析综合实验:固相微萃取纤维的制备及在有机氯农药富集和分析中的应用*

设计了一个综合性仪器分析实验:固相微萃取纤维的制备及应用。实验内容包括微孔有机聚合物固相微萃取纤维的制备、红外光谱表征、固相微萃取实验条件优化和气相色谱测定有机氯农药含量等4个部分。通过综合运用多种仪器分析实验手段,加深了学生对分离富集技术的了解,巩固了学生对仪器分析课程中的气相色谱法、红外光谱法相关内容的掌握,培养学生构建一个完整、科学的仪器分析操作流程,形成综合性思维能力。     

仪器分析实验多媒体教学软件的研制

开发了一个具有远程互动式功能的仪器分析实验多媒体教学软件,内容包括仪器分析实验教学中的基础理论、背景知识、预习测试、实验报告、实验讨论、实验操作技能规范等。     

气相色谱相邻组分分离度与柱温关系的计算机模拟实验

仪器分析是化学及化学相关专业的一门专业基础课程。由于仪器分析实验所用的仪器大多价格昂贵 ,而且分析仪器的发展更新很快 ,使仪器分析实验课明显存在着仪器短缺 ,实验开设不足 ,虽投入人力较多 ,但教学效果却不理想等问题[1] 。利用计算机辅助色谱分析实验教学是解决这个问题的好办法。我们开发了一套“计算机模拟色谱分析实验”软件 ,用于教学实践 ,效果良好。现介绍其中的计算机模拟柱温对气相色谱组分保留值及相邻组分分离影响的实验。1　理论部分　　在气相色谱分析中 ,当固定相选定后 ,柱温就成为最重要的操作参数 ,组分的调整保留…     

中学教师研发出可量产仪器,激励仪器仪表行业奋进

正实验仪器是自然科学具体实验时用到的仪器,主要是物理学、化学、生物学使用仪器较多。实验仪器的研发在常人看来应该是一项艰巨的任务,在刚刚结束的广东省中学物理和小学科学实验教师实验操作与创新技能竞赛中,广东省深圳市龙岗区实验学校教师成慧珍研发的电功率实验探究仪获得省一等奖,解决了实验中教学的难题,并且已经申请了国家专利。除了获奖的电功率实验探究仪外,李沛东的参赛作品《显微镜观察微生物的系列创新实验器材》也取得了不     

研究生仪器分析实验课程教学实践与探索

为了解决仪器分析实验选课困难的问题,南开大学环境学院自主开设了研究生仪器分析实验课程。立足于环境学科专业特色,结合学院大型仪器平台日常测试工作中遇到的问题,定制了研究生仪器分析实验教学体系,并融入了创新式教学方法,旨在培养本学院研究生的实践动手能力和应用创新能力,为之后的专业科研工作打下基础。多年的教学实践表明,由学院开设的研究生仪器分析实验课程不仅有利于提升本学院师生的专业技术水平,更加推动了学科的整体发展。     

提高高聚物化学分析结果准确度的方法

从分析方法、分析过程、仪器与试剂、实验环境条件、试样组成的变动性、试样中被测组分分布的不均匀性等方面分析了高聚物材料化学分析结果的误差来源,提出了提高高聚物化学分析结果准确度的方法。     

国内光催化研究进展简述

分1975~1985, 1985~1995和1995~2012三个时期简要介绍了国内光催化研究进展, 主要侧重于光催化材料及其改性、应用和反应机理方面的研究进展, 并指出了当前光催化领域存在的一些重要问题和未来的发展趋势, 涉及到光解水、CO₂还原、环境净化和选择性有机合成等方面.     

青蒿素研究进展

青蒿素是目前治疗疟疾的特效药。本文对自青蒿素发现以来的最新研究进展进行了比较详尽的综述。内容包括: 青蒿素的发现及历史, 青蒿素的来源, 青蒿素的全合成,青蒿素的生物合成, 青蒿素衍生物以及植物组织培养生产青蒿素。     

Interpretation of inorganic arsenic metabolism in humans in the light of observations made in vitro and in vivo in the rat

The toxicity of inorganic trivalent arsenic for living organisms is reduced by in vivo methylation of the element. In man, this biotransformation leads to the synthesis of monomethylarsonic (MMA) and dimethylarsinic (DMA) acids, which are efficiently eliminated in urine along with the unchanged form (As_i). In order to document the methylation process in humans, the kinetics of As_i, MMA and DMA elimination were studied in volunteers given a single dose of one of these three arsenicals or repeated doses of As_i. The arsenic methylation efficiency was also assessed in subjects acutely intoxicated with arsenic trioxide (As₂O₃) and in patients with liver diseases. Several observations in humans can be explained by the properties of the enzymic systems involved in the methylation process which we have characterized in vitro and in vivo in rats as follows: (1) production of As_i metabolites is catalyzed by an enzymic system whose activity is highest in liver cytosol; (2) different enzymic activities, using the same methyl group donor (S-adenosylmethionine), lead to the production of mono- and di-methylated derivatives which are excreted in urine as MMA and DMA; (3) dimethylating activity is highly sensitive to inhibition by excess of inorganic arsenic; (4) reduced glutathione concentration in liver moderates the arsenic methylation process through several mechanisms, e.g. stimulation of the first methylation reaction leading to MMA, facilitation of As_i uptake by hepatocytes, stimulation of the biliary excretion of the element, reduction of pentavalent forms before methylation, and protection of a reducing environment in the cells necessary to maintain the activity of the enzymic systems.     

Recent Advances in Analytical Methodology for in vivo Electrochemistry in Mammals

Electrochemistry is one of the most advanced techniques for monitoring neurochemical activities in the living brain because electrochemical approaches bear the advantageous features of high spatial and temporal resolutions, which facilitate its tremendous potential in investigating the highly spatially heterogeneous brain system and the fast dynamics of neurochemical activities. On the other hand, since brain is the most complicated organ in the sense of its numerous kinds of neurochemical species, high selectivity is always required for any analytical methods that approach the brain. In this review, we will discuss various electrochemical methodologies to achieve selective detection of neurochemicals in mammalian brain and the strategies developed mainly by our group towards selective monitoring of both electrochemically active and inactive neurochemicals. At the end, we will discuss possible solutions towards brain mapping of neurochemical species and combination of neurochemical detection strategy with electrophysiology as the direction of future development of electroanalysis in living brain.     

Use of NAA in marine environment and in archaeology in Greece

Neutron activation analysis (NAA) is a very sensitive and accurate multielement analytical method that is widely applied to the investigation of environmental and archaeological problems. The first part of this paper is a review of pollution studies of toxic trace elements in sediments, seawater and marine organisms of Saronikos Gulf, Greece by NAA. The second part of this paper is a review of provenance studies based on minor and trace element research in ancient ceramics, obsidian, flint, limestone, marble and lead by Instrumental NAA, performed at the NCSR Demokritos.     

Electrolysis in nanochannels for in situ reagent generation in confined geometries

In situ generation of reactive species within confined geometries, such as nanopores or nanochannels is of significant interest in overcoming mass transport limitations in chemical reactivity. Solvent electrolysis is a simple process that can readily be coupled to nanochannels for the electrochemical generation of reactive species, such as H(2). Here the production of hydrogen-rich liquid volumes within nanofluidic structures, without bubble nucleation or nanochannel occlusion, is explored both experimentally and by modeling. Devices comprised of multiple horizontal nanochannels intersecting planar working and quasi-reference electrodes were constructed and used to study the effects of confinement and reduced working volume on the electrochemical reduction of H(2)O to H(2) and OH(-). H(2) production in the nanochannel-embedded electrode reactor output was monitored by fluorescence emission of fluorescein, which exhibits a pH-dependent emission intensity. Initially, the fluorescein solution was buffered to pH 6.0 prior to stepping the potential cathodic of E(0)' for the generation of OH(-) and H(2). Because the electrochemical products are obtained in a 2:1 stoichiometry, local measurements of pH during and after the cathodic potential steps can be converted into H(2) production rates. Independent experimental estimates of the local H(2) concentration were then obtained from the spatiotemporal fluorescence behavior and current measurements, and these were compared with finite element simulations accounting for electrolysis and subsequent convection and diffusion within the confined geometry. Local dissolved H(2) concentrations were correlated to partial pressures through Henry's Law and values as large as 8.3 atm were obtained at the most negative potential steps. The downstream availability of electrolytically produced H(2) in nanochannels is evaluated in terms of its possible use as a downstream reducing reagent. The results obtained here indicate that H(2) can easily reach saturation concentrations at modest overpotentials.     

乙基香兰素研究前景

报导了近几十年来国内外关于乙基香兰素的研究进展与动态,并简单介绍了本文作者在该方面所取得的研究成果,参考文献33篇。     

Reactions in droplets in microfluidic channels

Fundamental and applied research in chemistry and biology benefits from opportunities provided by droplet-based microfluidic systems. These systems enable the miniaturization of reactions by compartmentalizing reactions in droplets of femoliter to microliter volumes. Compartmentalization in droplets provides rapid mixing of reagents, control of the timing of reactions on timescales from milliseconds to months, control of interfacial properties, and the ability to synthesize and transport solid reagents and products. Droplet-based microfluidics can help to enhance and accelerate chemical and biochemical screening, protein crystallization, enzymatic kinetics, and assays. Moreover, the control provided by droplets in microfluidic devices can lead to new scientific methods and insights.     

Conferences in Chemistry Held in 2022

Russian Chemical Bulletin -