Review on the study of mercury/silver ions-pyrimidine base pairs in DNA duplexes and their application in detection technology北大核心CSCD

Nucleic acids and their analogues are getting more and more attention. Metal-mediated base pairs as a kind of simple and functionalized nucleic acids in special positions have widened the scope of application of functional nucleic acids and their analogues. In this type of base pairs, the representative is the interaction between metal ions and pyrimidine bases, especially the research on thymine-Hg2+-thymine (T-Hg2+-T) and cytosine-Ag+-cytosine (C-Ag+-C) base pairs. This review summarizes the structure and mechanism of metal-mediate pyrimidine base pairs as well as the application in the biochemical analysis. It explores the mode and ratio of coordination between metal ions and base pairs, the effects on the stability of DNA helical structure, the related crystal structure and the three-dimensional configuration information in the DNA helix. The analytical application mainly includes various probes of metal ions, small molecules, protein and the detection of single nucleotide polymorphism. Among them the most widely used metal ions detection, and its combination with spectrum technology, visualization and amplification technology greatly promoted the rapid development of sensitive detection technology. In further studies, it is necessary to reveal the mechanism of interaction between T-Hg2+-T and C-Ag+-C, and more attention should be paid to combining of T-Hg2+-T and C-Ag+-C base pairs with other new technologies. The scope of practical application should also be further extended.     

贵阳市环境空气质量预报预警系统建立的探讨

分析了贵阳市空气质量预报中污染物、地形及下垫面、植被等关键影响因素。提出了贵阳市环境空气质量预报预警系统的整体架构,分别对排放源监测与管理系统、环境空气质量预报系统和污染预警与控制决策支持系统等三个核心部分进行阐述,进一步提出了贵阳市大气污染防控措施及防控机制。     

Kinetics of Solvent Blue and Reactive Yellow removal using microwave radiation in combination with nanoscale zero-valent iron

We investigated the efficiency and kinetics of the degradation of soluble dyes over the p H range 5.0–9.0 using a method employing microwave radiation in combination with nanoscale zero-valent iron(MW–n ZVI). The n ZVI particles(40–70 nm in diameter) were prepared by a liquid-phase chemical reduction method employing starch as a dispersant.Compared to the removal of Solvent Blue 36 and Reactive Yellow K-RN using only n ZVI,more rapid and efficient dye removal and total organic carbon removal were achieved using MW–n ZVI. The dye removal efficiency increased significantly with decreasing p H, but was negligibly affected by variation in the microwave power. The kinetics of dye removal by MW–n ZVI followed both an empirical equation and the pseudo first-order model, while the kinetics of dye removal using n ZVI could only be described by an empirical equation. It was also concluded that microwave heating of the dye solutions as well as acceleration of corrosion of n ZVI and consumption of Fe(II) were possible reasons behind the enhanced dye degradation.     

磁性固相萃取在环境分析中的应用

样品前处理直接影响污染物分析的准确性并很大程度上决定了目标物质的检测限。磁性固相萃取作为一种新兴的样品前处理技术,具有操作简单、消耗时间短、成本低等优点,克服了传统柱式固相萃取的缺陷,广泛应用于环境、化学、生物、药物分析等领域。文章介绍了磁性固相萃取技术及其流程,概述了各种磁性材料在痕量污染物富集分离过程中的应用现状,分析比较了不同表面修饰物质的磁性粒子的优缺点,并展望了磁性固相萃取未来的研究方向。     

环境保护市场化推进实践与思考

在分析环境保护市场化推进经验与制约瓶颈的基础上,从公共物品、准公共物品和私人物品特征明显的环境保护领域3个方面提出了环境保护市场化推进的重点领域与推进机制,并从加大监察执法力度、优化专项资金使用、强化政策引导和加强环保市场监管等方面提出了环境保护市场化的推进措施与建议。     

油品长输管道泄漏事故原因分析及防范措施

分析了油品长输管道泄漏的3种主要原因:外力破坏、管道腐蚀穿孔和管道本体缺陷,并根据这3种主要原因提出了具有针对性的防范措施,通过这些措施的实施可以有效地降低管道的泄漏风险.     

呼和浩特武川县农村土壤5种重金属的测定

采集呼和浩特市武川县三个村庄15个土壤样品,并对5种重金属进行分析,结果显示:三个村15个点位土壤单项污染指数均小于1,土壤污染程度均属无污染,土壤环境质量分级为Ⅰ级。     

Two-year measurements of surface ozone at Dangxiong, a remote highland site in the Tibetan Plateau

Measurements of surface O3 and carbon monoxide(CO) were made from September 2009 to August 2011 at Dangxiong(30.48°N, 91.10°E, 4187 m a.s.l.), a remote highland site in a southern valley of the Nyainqêntanglha Mountains in the Tibetan Plateau, China. The monthly mean O3 mixing ratio ranged from 29.1 to 51.4 ppb, with an average of 38.5 ppb, and the maximum value was observed in May. The average diurnal cycle of O3 concentration showed a minimum in early morning and a maximum in the afternoon, with a broader "high platform" from the late morning to the late afternoon, and resembled that of surface wind speed. The concentration of surface O3 was highly significantly correlated with tropospheric column O3 over the regions surrounding Dangxiong and with that of surface O3 observed at a site north of the Nyainqêntanglha Mountains, suggesting a good regional representativeness of surface O3 at Dangxiong. In the afternoon when stronger winds blew, surface air showed distinct features of free-atmospheric air, with higher O3, lower CO, and lower relative humidity(RH). The negative O3–CO and O3–RH correlations in most months indicate a significant influence of air masses from the free troposphere. Trajectory analysis suggests that air masses originating from the south of the site make a negative net contribution to surface O3 and a positive contribution to CO and humidity, and those from the northwest sector contribute conversely to the respective quantities.     

混合酸浸提—原子吸收法测定土壤中铜

建立了混合酸浸提对土壤样品进行前处理,并运用空气-乙炔火焰原子吸收法(FAAS)分析土壤中铜的方法。结果表明:最佳前处理条件为混合酸HNO 3+HCl(1+1),浸提温度100℃,浸提时间120 min。该方法前处理简单,测定快速、结果准确,同时经多次进行加标试验验证,其结果样品测定相对标准偏差为2.2%,其回收率为95%~101%,方法可行,应用于土壤样品的微量元素分析。     

固城湖水环境污染状况与来源分析

对2001~2011年固城湖水环境污染状况评价与时空变化特征分析的基础上,探讨了固城湖的特征污染物及污染来源。结果表明,固城湖水质污染的主要超标因子为TN和TP;总体水质呈现先恶化再改善的趋势,污染由拦河网水域向小湖区水域扩散;固城湖湖体水质基本上劣于水环境功能区划要求;固城湖特征污染物为COD+M n、NH4-N、TN、TP、BOD 5;富营养化程度不断加重,之后又有所改善;氮磷污染的主要来源是水产养殖污染。