环境大气污染物检测能力验证结果评价

正环境大气污染物检测是环境监测工作的一个重要领域,随着环境监测技术水平的提高和环境保护工作的深入,大气中污染物的检测及质量控制工作越来越受到重视[1]。为提高环境大气污染物检测能力,保证检测数据的准确性和可靠性,环境监测管理部门多次组织大气环境监测考核,考核项目涉及二     

持久性有机污染物研究进展

持久性有机污染物(Persistent Organic Pollutants,POPs)是指在环境中难降解、高脂溶性、可以在食物链中富集,能够在大气中通过蒸发-冷凝作用远距离传输而影响到区域乃至全球环境的一类半挥发性毒性很高的污染物.面对POPs对人类健康和生态环境的巨大威胁,国际社会达成共识,在全球范围内采取协调一致的行动.2004年5月17日《关于持久性有机污染物的斯德哥尔摩公约》正式生效,目前已有包括我国在内的178个国家加入了该公约.当前纳入公约控制的POPs已有22种.此外,短链氯化石蜡、六     

毛细管色谱-质谱法测定环境大气中挥发性有机污染物

毛细管色谱-质谱法测定了环境大气中挥发性污染物。用液氧冷冻法和常温吸附法(TenaxGC)分别采集大气样品,然后用两种系统进行浓缩,并进入毛细管色谱-质谱体系,完成了有机污染物的定性定量分析。解决了一些色谱-质谱联用中的问题。并且还讨论了无分流进样问题,比较了两种采样方法。用此方法测定了某炼油厂环境大气中的污染物。     

理论计算评价光催化剂VOCs降解性能：g-C_3N_4量子点/石墨烯

正挥发性有机污染物VOCs是典型的大气污染物,对气体环境和人体健康产生严重的影响~1。因此,控制VOCs在大气中的排放刻不容缓~2。目前利用光催化剂降解污染物来有效控制VOCs的技术手段吸引了研究者的广泛关注~3。虽然在实验过程中已采用多种技术手段去研究高效光催化剂,并了解对应的催化机理~4。但对于从电子和原子水平深入剖析光催化机理,     

预浓缩/色谱-质谱测量大气中挥发性有机硫化合物

硫循环是生物地化循环中最复杂的循环之一. 近年来,由于人类活动的影响,大气中硫化物含量急剧增加. 这些硫化物与大气中自由基发生作用,形成SO2、H2SO4和硫酸盐, 导致环境酸化, 酸沉降加剧.硫酸盐气溶胶的形成还改变了大气云层特性,影响大气臭氧含量的垂直分布以及大气热量辐射,对温室效应有一定的贡献[1-3].挥发性有机硫化合物中的甲硫醇(MT),甲硫醚(DMS),二硫化碳(CS2)和二甲二硫(DMDS)还是国家标准控制《恶臭污染物排放标准》中规定的4种恶臭气体,对大气环境质量造成一定的影响.     

大气污染物中人工放射性铯-钚-铀同位素示踪技术的发展与应用

近年来,我国雾霾形式的大气污染频发,严重影响国人健康和社会经济发展。目前所知,我国大气污染物来源复杂且具有独特性,其源解析研究对于大气污染物防治具有重要意义。随着放射性同位素示踪技术的发展,利用其研究大气污染物来源的问题备受关注。放射性同位素示踪技术及其在环境科学领域中的应用研究已取得了较大成就,特别是利用放射性同位素示踪环境污染物来源等方面。目前已有多种放射性同位素被用于大气污染物源解析研究。本文简要介绍了人工放射性核素铯、钚和铀同位素比值在大气污染物源解析研究中的发展和应用,并提出了存在的问题以及未来的发展趋势,希望进一步推动放射性同位素示踪技术在环境科学特别是在大气污染防治中的应用和发展。     

酸雨、铝-森林的"艾滋病毒"

纯净的降水,在温度为25℃,1个大气压下,pH大约是5.65,呈弱酸性.但是,由于大气中含有天然的或人为的污染物,如NOx(NO、NQ2)、SQ2等酸性气体,降水过程中(云中云水酸化及云下降水下落过程对大气冲刷而酸化)将大气中的SQ2和NOx以及其他杂质,通过化学反应生成亚硫酸、硫酸、硝酸等,因而使雨水酸化.雨水的pH小于5.6即为酸雨.酸雨问题是同工业高度发展联系在一起的.酸雨将成为21世纪最大的环境问题之一,正在危及人类的生存,它与温室效应、臭氧层破坏一起被称为全球的三大环境危机.酸雨最显而易见的危害是森林的大面积枯死及古建筑石雕被腐蚀.     

酸雨、铝—森林的“艾滋病毒”

纯净的降水,在温度为25℃,1个大气压下,pH大约是5.65,呈弱酸性.但是,由于大气中含有天然的或人为的污染物,如NOx(NO、NQ2)、SQ2等酸性气体,降水过程中(云中云水酸化及云下降水下落过程对大气冲刷而酸化)将大气中的SQ2和NOx以及其他杂质,通过化学反应生成亚硫酸、硫酸、硝酸等,因而使雨水酸化.雨水的pH小于5.6即为酸雨.酸雨问题是同工业高度发展联系在一起的.酸雨将成为21世纪最大的环境问题之一,正在危及人类的生存,它与温室效应、臭氧层破坏一起被称为全球的三大环境危机.酸雨最显而易见的危害是森林的大面积枯死及古建筑石雕被腐蚀.……     

Criegee中间体气相反应热力学的G2理论计算

Criegee中间体已被认为是大气中一些重要污染物的来源，是引发大量次级反应的关键物质，与光化学氧化剂、有机过氧化物的产生，以及与酸雨、大气光化学烟雾和森林衰退等许多环境问题有关[1-4]．但由于Criegee中间体寿命短，对其可能参与的一些大气化学反应进行实验研究有一定难     

二氧化硫的制取与性质实验一体化的创新设计

二氧化硫是一种有毒的气体,也是大气中的一种主要污染物。为了培养学生的环境意识,消除二氧化硫对教学环境的污染,设计了一体化的二氧化硫制取与性质实验。     

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 -