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991.
利用石家庄地区1990~2013年电力污闪事故发生的详细资料,归纳整理出污闪发生的一般规律,结合诱发污闪发生的天气现象和气象要素,综合在不同气象条件下污闪发生的可能性大小,对其进行分级,给出污闪发生级别的综合预测标准,从而判定预测电力污闪发生的气象指数,并提出必要安全预防措施。结果表明:当气温15.6℃,相对湿度45%,风速4.8 m/s时天气晴朗,不会发生污闪;在相对湿度≥80%,风速≤2.0 m/s时,气温在-7.5~7.5℃时出现雾,气温在-4.5~4.5℃时出现积雪或结冰,极易发生污闪;在相对湿度≥80%,风速≤2.0 m/s,气温在-4.5~4.5℃时出现液态、混合或固态降水、轻雾,容易发生污闪。 相似文献
992.
介绍了针对中国海域海洋污染环境保障系统的研究进展,并阐述中子活化分析(Neutron Activation Analysis,NAA)方法在其中的可能作用。该系统基于对海洋三维流场的预报与分析,对海洋污染物可能的扩散路径与影响区域、污染源头的可能位置进行推测,并结合GIS技术整合相关的环境敏感信息,为将污染物造成的危害降到最低提供决策支持。基于该系统技术的渤黄海海洋污染物预测预警系统已经实现业务化运行多年,并在中国沿海污染事故应急中多次获得成功的经验。目前,针对重金属与放射性污染物的环境保障系统正处于理论实验阶段,由于NAA方法特别适合用于对部分重金属及放射性物质的检测,因此NAA方法对实现海洋重金属及放射性污染物的监测及预测预警具有非常重要的实用价值。 相似文献
993.
Jos E Celis Winfred Espejo Ricardo Barra Daniel Gonzalez-Acua Francisca Gonzalez Solange Jara 《极地研究(英文版)》2015,(1)
In recent decades, polar regions of the planet have witnessed an increase in human presence. Antarctica is considered one of the most pristine regions of the world, but it could be affected by pollutio... 相似文献
994.
Interactions between climate change and contaminants 总被引:1,自引:0,他引:1
There is now general consensus that climate change is a global threat and a challenge for the 21st century. More and more information is available demonstrating how increased temperature may affect aquatic ecosystems and living resources or how increased water levels may impact coastal zones and their management. Many ecosystems are also affected by human releases of contaminants, for example from land based sources or the atmosphere, which also may cause severe effects. So far these two important stresses on ecosystems have mainly been discussed independently. The present paper is intended to increase awareness among scientists, coastal zone managers and decision makers that climate change will affect contaminant exposure and toxic effects and that both forms of stress will impact aquatic ecosystems and biota. Based on examples from different ecosystems, we discuss risks anticipated from contaminants in a rapidly changing environment and the research required to understand and predict how on-going and future climate change may alter risks from chemical pollution. 相似文献
995.
Changes in the terms and direction of international trade in seafood, an increased understanding of and concern for the public health risk imposed by seafood products, and advances in information management technology combine to open opportunities to manage more effectively seafood-borne risk. Present regulatory mandates and programs lack sufficient integration for effective risk mitigation and do not adequately reflect the trans-national nature of seafood trade or the increased complexity of seafood production. This paper argues that the concept of a "chain of custody" - from the ocean to the final consumer - provides a useful integrating framework for understanding and refining efforts to reduce public health concerns surrounding the consumption of seafood. 相似文献
996.
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998.
《The Journal of geography》2012,111(6):558-569
Abstract This report addresses the question of groundwater quality in a context of economic development and heterogeneous land use. Seven wells, each actively producing for the public water supply, and together providing 37 percent of the total aquifer production of four municipios, were tested in three topographic basins. Major land use categories, including agriculture, urbanization, and industry, were identified throughout the basins. Well samples were drawn three times during a six-month period and analyzed for a set of 15 water quality parameters including biological indicators. The most common pollutants detected were heavy metals, nitrate, arsenic, and semivolatile organic compounds. Wells surrounded by agricultural and commercial activities were contaminated by nitrate, mercury, lead, and phthalates. Wells in mixed residential and industrial settings had concentrations of semivolatile organic compounds and lead. The presence of noxious chemicals in the public water supply, even in relatively small amounts, threatens the viability of the groundwater reservoir. Both operational and policy aspects of water quality should be discussed in the context of urban and economic development. 相似文献
999.
1000.
Rock coatings are frequent on natural rock outcrops and even more on stone surfaces of historical buildings and monuments. They are interesting as some of them have a protective effect against erosion. In the last 30 years, research on rock coatings has been performed separately on either buildings or natural outcrops. This paper studies and compares thin coatings found on granitic rock surfaces of historical buildings with coatings found on natural granite outcrops in a same climatic area (NW Spain) by analysing their surface and cross-sections. As rock surfaces of buildings have known age they can be used to assess rates of weathering and coating growth. This is the first comparative study of formation of coatings on natural and built surfaces in the same region. Both endogenous (rock characteristics) and exogenous factors (climatic conditions, air pollution) that could affect the coatings formation are considered to assess the origin and formation of coatings. X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF) analyses of the underlying rocks, XRD analyses of the coatings and Scanning Electron Microscopy (SEM) observations of surface and cross-sections of the coatings, performing Energy Dispersive Spectrometry (EDS) and X-ray maps, were carried out to establish their composition. Fieldwork and results indicate that natural outcrops are widely covered by biological coatings or coatings formed due to rock weathering, while coatings found on rock ashlars are highly variable with air pollution, other building materials, organic droppings and micro-environmental factors contributing to coatings on rock ashlars in a more significant way than substrate characteristics and exposure time. 相似文献