Elevated mercury concentrations in failed eggs of Snowy Plovers at Point Reyes National Seashore     

Schwarzbach SE  Stephenson M  Ruhlen T  Abbott S  Page GW  Adams D 《Marine pollution bulletin》2005,50(11):1444-1447

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Estuarine phytoplankton group-specific responses to sublethal concentrations of the agricultural herbicide,atrazine     

Pinckney JL  Ornólfsdóttir EB  Lumsden SE 《Marine pollution bulletin》2002,44(10):1109-1116

Atrazine is a common agricultural herbicide that is readily transported into estuaries through surface water runoff. In this study, we determined the short-term (24-48 h) sublethal effects of atrazine on estuarine phytoplankton biomass and community composition. Phytoplankton group-specific responses to atrazine exposure (25 microgh(-1)) were measured using natural water samples collected from two locations in Galveston Bay, Texas. Addition bioassays, coupled with HPLC pigment analysis, were used to quantify changes in the relative abundances of algal groups. For all algal groups except prasinophytes, the addition of atrazine in combination with nitrate was not significantly different from nitrate additions alone. These results suggest no significant negative effect of atrazine on phytoplankton under the specified environmental conditions for the bioassays. Although low concentrations of atrazine may have minimal impacts on phytoplankton, herbicide loadings need to be further characterized before generalizations can be applied to estuarine and coastal ecosystems.  相似文献   

天然沸石对提高TiO2光催化活性的作用   总被引：1，自引：1，他引：0  

牟柏林  李芳菲  侯天意  孙申美  王瑛玮  祖胜男 《吉林大学学报(地球科学版)》2006,36(4):668-672

以天然沸石为载体,研究了其负载TiO2后对甲基橙溶液的光催化降解效果,探讨了TiO2与沸石的结合类型。通过对负载前后反应动力学模式变化的研究,阐释TiO₂/沸石体系的光催化反应进程。从复合前后样品的AFM、IR、发射光谱变化上看,部分TiO₂与沸石载体形成了新的Ti－O－Si或Ti－O－Al的化学键。光催化实验结果和动力学分析显示,在反应的初始阶段,当TiO₂中引入多孔的沸石载体后,催化剂对甲基橙的降解过程由原来纯粹的吸附控制模式向反应控制模式转变,但还没有达到纯粹的反应控制的程度。沸石载体是通过提高吸附过程的速率,来提升初始阶段的光催化反应速率（R₀）的。  相似文献   

原油在密西西比河谷型矿床形成中的作用：来自辛辛那提穹窿的证据     

Kesl.  SE 王登红 《国外地质与勘测》1995,(3):17-21

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航磁资料网格化几种方法的对比和探讨     

罗维俊  王瑛 《物探化探计算技术》1983,(4)

航磁资料网格化,是实现航磁资料整理自动化的重要环节。目前,国外在航空物探测量中巳普遍建立了从空中自动数字收录到绘制出各种图件的自动处理系统。在国内,有的兄弟单位也正在研制或引进。网格化的方法很多,各单位往往各自选用一种方法。例如:加拿大的一些物探公司在编制航磁图中使用样条插值法进行网格化,美国乔梅特公司则用的是扇形网格化方法。究竟选用哪种方法为好?网格化结果的精度如何?文献上找不到答案。  相似文献   

Terrestrial pollutant runoff to the Great Barrier Reef: An update of issues, priorities and management responses   总被引：1，自引：0，他引：1  

Brodie JE  Kroon FJ  Schaffelke B  Wolanski EC  Lewis SE  Devlin MJ  Bohnet IC  Bainbridge ZT  Waterhouse J  Davis AM 《Marine pollution bulletin》2012,65(4-9):81-100

The Great Barrier Reef (GBR) is a World Heritage Area and contains extensive areas of coral reef, seagrass meadows and fisheries resources. From adjacent catchments, numerous rivers discharge pollutants from agricultural, urban, mining and industrial activity. Pollutant sources have been identified and include suspended sediment from erosion in cattle grazing areas; nitrate from fertiliser application on crop lands; and herbicides from various land uses. The fate and effects of these pollutants in the receiving marine environment are relatively well understood. The Australian and Queensland Governments responded to the concerns of pollution of the GBR from catchment runoff with a plan to address this issue in 2003 (Reef Plan; updated 2009), incentive-based voluntary management initiatives in 2007 (Reef Rescue) and a State regulatory approach in 2009, the Reef Protection Package. This paper reviews new research relevant to the catchment to GBR continuum and evaluates the appropriateness of current management responses.  相似文献   

The influence of a season of extreme wet weather events on exposure of the World Heritage Area Great Barrier Reef to pesticides     

Kennedy K  Devlin M  Bentley C  Lee-Chue K  Paxman C  Carter S  Lewis SE  Brodie J  Guy E  Vardy S  Martin KC  Jones A  Packett R  Mueller JF 《Marine pollution bulletin》2012,64(7):1495-1507

The 2010-2011 wet season was one of extreme weather for the State of Queensland, Australia. Major rivers adjacent to the Great Barrier Reef (GBR) were discharging at rates 1.5 to >3 times higher than their long term median. Exposure to photosystem II herbicides has been routinely monitored over a period of up to 5 years at 12 inshore GBR sites. The influence of this wet season on exposure to photosystem II herbicides was examined in the context of this long-term monitoring record and during flood plume events in specific regions. Median exposures expressed as diuron equivalent concentration were an average factor of 2.3 times higher but mostly not significantly different (p<0.05) to the median for the long-term monitoring record. The herbicides metolachlor and tebuthiuron were frequently detected in flood plume waters at concentrations that reached or exceeded relevant water quality guidelines (by up to 4.5 times).  相似文献   

从区域安全建设到风险管理体系的形成--从第一届世界风险大会看灾害与风险研究的现状与发展趋向   总被引：20，自引：3，他引：17  

史培军  邹铭  李保俊  周俊华  王瑛 《地球科学进展》2005,20(2):173-179

综述了第一届世界风险大会关于灾害与风险科学研究的进展,分析了其发展趋势,并对我国加强这一领域的研究提出了对策。灾害与风险研究的目标正在趋向一致,都集中在为可持续发展模式提供科学依据;基于灾害研究的区域安全建设正在向基于风险研究的区域风险管理体系转变,由此认为可持续发展模式就是接受一定风险水平条件下的区域发展模式,一定风险水平依赖于由区域经济水平与社会文化体系相关联的区域安全建设水平;加强我国灾害与风险科学研究的学科建设、国家实验室建设、重大项目的组织与实施已势在必行;重点开展灾害脆弱性评价体系与评价模型、风险评价体系与风险评价模型、典型区域灾害与风险管理范式、灾害与风险应急控制预案（情景分析）、灾害与风险区划等方面的研究。为此把灾害科学和风险科学,与全球变化科学和可持续发展科学统一纳入到地球系统科学体系之中,以加强与完善我国在这些领域的综合多学科交叉研究能力。  相似文献   

Characterization and identification of na-cl sources in ground water   总被引：6，自引：0，他引：6  

Panno SV  Hackley KC  Hwang HH  Greenberg SE  Krapac IG  Landsberger S  O'Kelly DJ 《Ground water》2006,44(2):176-187

Elevated concentrations of sodium (Na+) and chloride (Cl-) in surface and ground water are common in the United States and other countries, and can serve as indicators of, or may constitute, a water quality problem. We have characterized the most prevalent natural and anthropogenic sources of Na+ and Cl- in ground water, primarily in Illinois, and explored techniques that could be used to identify their source. We considered seven potential sources that included agricultural chemicals, septic effluent, animal waste, municipal landfill leachate, sea water, basin brines, and road deicers. The halides Cl-, bromide (Br), and iodide (I) were useful indicators of the sources of Na+-Cl- contamination. Iodide enrichment (relative to Cl-) was greatest in precipitation, followed by uncontaminated soil water and ground water, and landfill leachate. The mass ratios of the halides among themselves, with total nitrogen (N), and with Na+ provided diagnostic methods for graphically distinguishing among sources of Na+ and Cl- in contaminated water. Cl/Br ratios relative to Cl- revealed a clear, although overlapping, separation of sample groups. Samples of landfill leachate and ground water known to be contaminated by leachate were enriched in I and Br; this provided an excellent fingerprint for identifying leachate contamination. In addition, total N, when plotted against Cl/Br ratios, successfully separated water contaminated by road salt from water contaminated by other sources.  相似文献   

云南省农村乡镇地震灾害房屋损失评估   总被引：9，自引：0，他引：9       下载免费PDF全文

王瑛  史培军  王静爱 《地震学报》2005,27(5):551-560

根据1990——2000年20余次云南省地震的房屋损坏调查数据,建立了目前云南省农村居民最主要的4类房屋地震脆弱性模型（烈度-损失率曲线）;进而利用设定地震灾害损失模拟方法, 基于2002年云南省房屋状况, 模拟了历史上的破坏性地震如果再次发生, 将造成的云南省房屋的经济损失. 误差分析表明, 该模拟计算方法实用性强, 对一般性地震的模拟误差在30%左右. 将云南省886——2002年的398次地震依次进行了房屋经济损失模拟. 结果表明, 云南省年均因地震引起的经济损失约为4.1亿元, 占当年云南省GDP值2 232.32亿元的0.18%. 由于房屋造价的上涨和农村居民人均住房面积的增加,历史上的强震一旦今天再次发生, 对云南省经济的影响将远远大于当年.   相似文献