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371.
王伟 《中国环境监测》2019,35(1):135-141
建立了基质固相分散-ASE提取-GC/MS法同时测定土壤中8种有机氯农药和16种多环芳烃的方法。对方法的线性、检出限、精密度、回收率及土壤质控样品进行了分析,结果表明,8种有机氯农药和16种多环芳烃线性良好,相关系数为0.997 5~0.999 8,方法检出限为0.39~1.57μg/kg,空白加标样品的相对标准偏差小于20%,实际土壤样品加标回收率为60.6%~125%,土壤质控样品结果均在范围内。该方法能够满足土壤中8种有机氯农药和16种多环芳烃的检测要求。  相似文献   
372.
Atmospheric releases of krypton-85, from the nuclear fuel reprocessing plant at the AREVA NC facility at La Hague (France), were used to test Gaussian models of dispersion. In 2001-2002, the French Institute for Radiological Protection and Nuclear Safety (IRSN) studied the atmospheric dispersion of 15 releases, using krypton-85 as a tracer for plumes emitted from two 100-m-high stacks. Krypton-85 is a chemically inert radionuclide. Krypton-85 air concentration measurements were performed on the ground in the downwind direction, at distances between 0.36 and 3.3 km from the release, by neutral or slightly unstable atmospheric conditions. The standard deviation for the horizontal dispersion of the plume and the Atmospheric Transfer Coefficient (ATC) were determined from these measurements. The experimental results were compared with calculations using first generation (Doury, Briggs) and second generation (ADMS 4.0) Gaussian models. The ADMS 4.0 model was used in two configurations; one takes account of the effect of the built-up area, and the other the effect of the roughness of the surface on the plume dispersion. Only the Briggs model correctly reproduced the measured values for the width of the plume, whereas the ADMS 4.0 model overestimated it and the Doury model underestimated it. The agreement of the models with measured values of the ATC varied according to distance from the release point. For distances less than 2 km from the release point, the ADMS 4.0 model achieved the best agreement between model and measurement; beyond this distance, the best agreement was achieved by the Briggs and Doury models.  相似文献   
373.
煤层注水防治煤与瓦斯突出机理的研究现状与进展   总被引:8,自引:0,他引:8  
为了深入研究煤层注水的防突机理,在对国内外煤层注水防治煤与瓦斯突出机理研究的基础上,综述煤层注水影响煤体力学性质、采场应力分布及煤体瓦斯解吸特性3方面的研究现状;进而分析我国在煤层注水防突机理研究方面存在的问题,提出当前应急需解决注水对煤体瓦斯的抑制解吸效应问题。笔者认为:确定抑制解吸效应考察、煤体孔隙特性变化及注水煤样吸附解吸甲烷特性等课题的研究是深入探讨的方向,研究成果为进一步认识煤层注水的防突机理提供理论依据。  相似文献   
374.
南京典型古建筑的消防现状调查和消防对策   总被引:1,自引:1,他引:0  
通过对江苏南京代表性古建筑朝天宫、甘熙故居、鸡鸣寺和净觉寺的实地深入调查,从结构、材料、内容、布局和环境等方面分析了古建筑普遍存在的火灾危险性,考察了古建筑中现代消防设施建设、消防资金投入、消防管理措施和现代消防材料和技术应用的现状,发现多数古建筑在消防防护方面仍处于保守、常规、落后和消极的状态。为实现对古建筑价值的最大限度保护,应从消防安全布局、消防站建设、消防通道设计、消防给水供应、消防通讯保障、消防装备配置等方面进行性能化设计和规划;在遵循“修旧如旧”的修缮和维护原则下,需要勇于尝试和接纳纳米材料等新型化学保护材料和技术。  相似文献   
375.
Abstract

Members of TRP receptor family are involved in response to acidification. Here, we determined the effect of capsaicin, one of the TRP receptor activators, on hemolymph acid-base status in the American cockroach. Periplaneta americana adult individuals were injected with lactic acid (5% or 10%) and exposed to 100?µM capsaicin solution. Hemolymph pH was measured 15?min, 1, 4, 8 and 24?h after lactic acid and capsaicin application with a glass microelectrode. The results demonstrated that cockroaches recover from acidosis within 4?h from acid injection. Capsaicin impaired the buffering capacity of insects’ hemolymph, resulting in significant drop of hemolymph pH observed even 24?h after application. Joint action of capsaicin and acidosis reveals new insight into possible mechanism of capsaicin action on TRP receptors in insects.  相似文献   
376.
Effective environmental management requires documentation of ecosystem status and changes to that status. Without long-term data, short-term natural variability can mask chronic and/or cumulative impacts, often until critical levels are reached. However, a trade-off generally occurs between sampling in space and time. This study analyses a spatially and temporally nested long-term (12 years) monitoring programme conducted on benthic macrofauna in a large harbour. Sampling was carried out at six sites for 5.5 years, after which only two sites were sampled for the next 5 years. After this period, all six sites were sampled for another 2 years. While ecology is frequently thought of being highly variable, this design was able to detect trends, and cycles, in abundance, with only around 10% of species at each site exhibiting unpredictable temporal variability. Sites exhibiting similar trends in the abundance of a species over the 12.5-year period were generally spatially contiguous, and the spatial scale of change could be assessed. Continuous sampling at two sites identified whether changes in unsampled sites were related to long-term cycles. Moreover, this sampling provided a long-term background of temporal fluctuations against which to assess the ecological significance of observed changes.  相似文献   
377.
Evaluating the impacts of point source discharges on fish species in estuarine environments can be challenging because of a paucity of resident species. We evaluated the biology of rock gunnel (Pholis gunnellus) at three relatively uncontaminated sites in the Bay of Fundy, along the Atlantic coast of Canada. Rock gunnel are seasonally resident (April to November) in tide pools, but little was known about their life history in Atlantic Canada or their potential for use for monitoring environmental quality. Fish were collected between April and November, and ranged from 2.46 g--15.2~g in weight and 97 mm-170 mm in length, with a maximum age of 7 years. Both males and females were similar in size, and both reached sexual maturity at a size of 5.5 g. Organ weights and condition indices of fish were stable from spring when they returned from offshore (April to May) until late summer (August to September), but fall fish (October to November) had slightly larger gonads, livers and condition indices. Rock gunnel may be a useful indicator to provide insight into local impacts of point sources over a short time period. However, they do not provide adequate information on reproductive development and performance since they are not exposed to onshore contaminants during the periods of gonadal development that have most commonly found to be sensitive to anthropogenic stressors.  相似文献   
378.
新疆水环境质量监测现状、问题及对策   总被引:1,自引:0,他引:1  
杨春  沈志 《干旱环境监测》2009,23(3):134-137,151
水环境质量监测是环境质量监测的重要组成部分,其任务是说清区域水环境质量现状、问题及变化趋势,为环境管理决策提供依据。本文简要介绍了新疆环保系统的水环境质量监测工作现状及存在问题,并提出了相应的对策建议,以期为进一步改进新疆水环境质量监测与管理工作提供参考。  相似文献   
379.
宁波市环境空气中VOCs污染状况及变化趋势分析   总被引:7,自引:4,他引:3  
基于近7年来的连续监测数据,对宁波市环境空气中挥发性有机物(VOCs)的污染状况及变化趋势进行了初步分析。研究表明:在宁波市环境空气中检测出94种VOCs,其主要成分是饱和烷烃、芳烃、烯烃、卤代烃、卤代芳烃、含氧有机物等,有37种属有毒有害物质,其中苯系物含量最高;宁波市环境空气中苯系物的污染程度与国内外城市基本处于同一水平,近年来的污染状况变化不大,没有明显恶化;空间分布特征显示一类保护区VOCs的排放以天然源为主,二类各功能区VOCs的排放由天然源和局部人为污染源共同形成,三类区以工业污染源排放为主;时间变化趋势显示VOCs在冬季和春季的平均浓度比其他季节高,VOCs的日变化基本呈现2个主浓度峰值特征,跟城市交通流量变化具有很好相关性。  相似文献   
380.
湖南省涉汞行业汞污染现状及防治监管对策   总被引:1,自引:1,他引:0  
综述了环境中汞污染的来源及其危害,结合湖南省汞污染排放源现状调查,摸清了湖南省主要涉汞行业的基本情况。为有效进行汞污染的防治和监管,提出了加快工业结构转型、加强汞污染源信息管理、进一步提高涉汞行业的准入条件、逐步推进重点行业的汞减排等具体措施和建议。  相似文献   
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