首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   243篇
  免费   4篇
  国内免费   2篇
安全科学   6篇
废物处理   6篇
环保管理   17篇
综合类   79篇
基础理论   52篇
污染及防治   73篇
评价与监测   6篇
社会与环境   10篇
  2023年   2篇
  2022年   5篇
  2021年   4篇
  2020年   6篇
  2019年   3篇
  2018年   8篇
  2017年   8篇
  2016年   15篇
  2015年   8篇
  2014年   17篇
  2013年   14篇
  2012年   15篇
  2011年   16篇
  2010年   15篇
  2009年   11篇
  2008年   17篇
  2007年   16篇
  2006年   10篇
  2005年   11篇
  2004年   10篇
  2003年   12篇
  2002年   8篇
  2001年   2篇
  1999年   2篇
  1998年   1篇
  1995年   1篇
  1994年   1篇
  1993年   2篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1984年   2篇
  1983年   1篇
排序方式: 共有249条查询结果,搜索用时 31 毫秒
41.
Scandinavia has one secondary lead smelter that recycles lead from approximately 85% of used car batteries in Scandinavia and which has been active since the 1940s. The smelter, situated in Landskrona, has undergone a comprehensive clean up programme during the last decade, during which time production has doubled, while at the same time discharges of dust and lead to the atmosphere have decreased.Top and depth soil samples were taken on a 0.5km×0.5Km grid throughout the city of Landskrona, which covers an area of approximately 15km2. Samples were analysed by ICPAES for a number of elements including Pb, Zn, Cu, Cd, As, Sb and Hg. Road dust samples from selected sites were collected and similarly analysed. Blood samples were taken from 37 volunteer schoolchildren (aged 8–11) from two schools in Landskrona. House dust samples were taken from each child's home. Soil samples were taken from homes which had gardens, public and school play areas. Elevated heavy metal concentrations were found in close proximity to the secondary lead smelter, and this soil enrichment influences the whole of the town, modified to some extent by the prevailing wind. The smelter does not influence the soil lead concentration at distances greater than 3.5km, where the soil reflects the background value for the area.Road dust samples also show decreases in lead concentrations with distance from the smelter. The average level of lead in house dust was considerably lower than that found in Birmingham, UK. Blood lead levels in the child population ranged from 1.5–5.1gdl–1, with a mean of 3.05gdl–1, showing a distinct decrease from those measured in 1978–82. No significant difference in blood lead concentrations with distance of the home from the smelter, nor between attenders at the two schools was revealed in the limited number of children studied.  相似文献   
42.
Experience with prenatal karyotyping of 237 fetuses with sonographic evidence of malformation is reported. Abnormal karyotype was found in 40 cases (16-8 per cent): chromosomal aberrations were found in 19 of the 178 fetuses with an isolated structural anomaly (10-6 per cent) and in 21 of the 59 fetuses with multiple malformations (35-6 per cent). Detailed cytogenetic and morphological information concerning fetuses affected by omphalocele, duodenal atresia, hydrocephalus, multicystic kidney, unilateral hydronephrosis and cystic hygroma is reported. The need for a very careful ultrasound evaluation of fetal anatomy in these pregnancies is stressed, as the risk of a chromosomal anomaly depends mainly on the existence of more than one ultrasonically diagnosed structural defect.  相似文献   
43.
Soils in clay pigeon shooting ranges can be seriously contaminated by heavy metals. The pellets contained in ammunition are composed of Pb, Sb, Ni, Zn, Mn and Cu. The total concentrations of these metals in soils, and the effects of their increasing levels on the arthropod community were investigated at seven sampling sites in a clay pigeon shooting range and compared with two controls. Research revealed that the spatial distribution of Pb and Sb contamination in the shot-fall area was strongly correlated with the flight path of the pellets. Ordination obtained through Redundance Analysis showed that Collembola, Protura and Diplura were positively correlated with major detected contaminants (Pb, Sb), while Symphyla showed a negative correlation with these pollutants. Determination of the soluble lead fraction in soil, and of its bioaccumulation in the saprophagous Armadillidium sordidum (Isopoda) and the predator Ocypus olens (Coleoptera), showed that a significant portion of metallic Pb from spent pellets is bioavailable in the soil and can be bioaccumulated by edaphic organisms, entering the soil trophic network, but without biomagnification.  相似文献   
44.
The source of PCDDs and PCDFs in automotive exhaust is not yet fully explained. The chlorinated hydrocarbons used in the formulation of lead-alkyl additives were suspected as a possible major source. Based on this, the decreasing use of leaded gasoline followed by its final ban (occurred on 1/1/2002, in Italy) should have resulted in a decreasing presence of PCDD/Fs in urban air and possibly some differences in their profile. To investigate these aspects, we monitored PCDD/Fs for one year starting in September 2001, at a medium-traffic road site in Rome, with weekly frequency. Results were then compared with those obtained in a previous study performed before the ban (from February 2000 to January 2001) at the same site. As compared with the previous study, the yearly-averaged overall PCDD/F concentration, as toxic equivalent of 2,3,7,8-TCDD, decreased from 60 to 50 fg m(-3) I-TEQ; it remained unchanged, however, if one sample with a particularly high PCDD/F content was excluded from each data set. The monthly trend confirmed the one found in the former study. On an annual basis, the two mean congener profiles were almost identical. The concentration levels and the constancy of profiles, as calculated for the two periods, do not support the hypothesis of a major role of leaded gasoline, substantially different from unleaded one, in contributing to PCDD/F air pollution.  相似文献   
45.
Use of municipal biowaste for composting instead of its disposal has become a major source of concern as regards contamination by hazardous substances. To elucidate the hazard potential of compost application, municipal biowaste was amended with 14C-labelled model substances (pyrene, simazine) and incubated in a pilot-scale composting simulation system. A mass balance incorporating the mineralization, metabolism and sorption of the two model substances was established over a period of 370 days. The results are quite different for the two chemicals, reflecting their intrinsic properties: more than 60% of the applied 14C-simazine resulted in non-extractable residues (NER). Silylation experiments indicated that the formation of NER from simazine and its metabolites was due to both physical entrapment in the matrix and chemical binding. The mineralization and formation of NER represented the major pathways of disappearance for pyrene during one year of composting, accounting for 60 and 26% of initially applied 14C-activity, respectively. Mineralization occurred delayed after the thermophilic phase. As regards remobilization, release of pyrene from NER during composting could be excluded, whereas simazine, data were inconclusive in this respect.  相似文献   
46.
Internationally agreed standard protocols for assessing chemical toxicity of contaminants in soil to worms assume that the test soil does not need to equilibrate with the chemical to be tested prior to the addition of the test organisms and that the chemical will exert any toxic effect upon the test organism within 28 days. Three experiments were carried out to investigate these assumptions. The first experiment was a standard toxicity test where lead nitrate was added to a soil in solution to give a range of concentrations. The mortality of the worms and the concentration of lead in the survivors were determined. The LC50s for 14 and 28 days were 5311 and 5395 microgPb g(-1)soil respectively. The second experiment was a timed lead accumulation study with worms cultivated in soil containing either 3000 or 5000 microgPb g(-1)soil. The concentration of lead in the worms was determined at various sampling times. Uptake at both concentrations was linear with time. Worms in the 5000 microg g(-1) soil accumulated lead at a faster rate (3.16 microg Pb g(-1)tissue day(-1)) than those in the 3000 microg g(-1) soil (2.21 microg Pb g(-1)tissue day(-1)). The third experiment was a timed experiment with worms cultivated in soil containing 7000 microgPb g(-1)soil. Soil and lead nitrate solution were mixed and stored at 20 degrees C. Worms were added at various times over a 35-day period. The time to death increased from 23 h, when worms were added directly after the lead was added to the soil, to 67 h when worms were added after the soil had equilibrated with the lead for 35 days. In artificially Pb-amended soils the worms accumulate Pb over the duration of their exposure to the Pb. Thus time limited toxicity tests may be terminated before worm body load has reached a toxic level. This could result in under-estimates of the toxicity of Pb to worms. As the equilibration time of artificially amended Pb-bearing soils increases the bioavailability of Pb decreases. Thus addition of worms shortly after addition of Pb to soils may result in the over-estimate of Pb toxicity to worms. The current OECD acute worm toxicity test fails to take these two phenomena into account thereby reducing the environmental relevance of the contaminant toxicities it is used to calculate.  相似文献   
47.
Understanding complex systems is essential to ensure their conservation and effective management. Models commonly support understanding of complex ecological systems and, by extension, their conservation. Modeling, however, is largely a social process constrained by individuals’ mental models (i.e., a small-scale internal model of how a part of the world works based on knowledge, experience, values, beliefs, and assumptions) and system complexity. To account for both system complexity and the diversity of knowledge of complex systems, we devised a novel way to develop a shared qualitative complex system model. We disaggregated a system (carbonate coral reefs) into smaller subsystem modules that each represented a functioning unit, about which an individual is likely to have more comprehensive knowledge. This modular approach allowed us to elicit an individual mental model of a defined subsystem for which the individuals had a higher level of confidence in their knowledge of the relationships between variables. The challenge then was to bring these subsystem models together to form a complete, shared model of the entire system, which we attempted through 4 phases: develop the system framework and subsystem modules; develop the individual mental model elicitation methods; elicit the mental models; and identify and isolate differences for exploration and identify similarities to cocreate a shared qualitative model. The shared qualitative model provides opportunities to develop a quantitative model to understand and predict complex system change.  相似文献   
48.
49.
This paper presents an analysis of the main environmental impact factors (noise, vibration, fumes, dust, vehicle traffic) associated with marble quarrying and processing in the Orosei industrial area and their effects. Solutions are also proposed to prevent, mitigate and, where possible, eliminate the impact on the environment. Using three-dimensional topographic models, the authors simulated quarry and industrial processing development, with projections over the next 10, 30 and 50 years. The aim of these simulations was to establish land management planning guidelines for the optimal and environmentally sustainable development of the Orosei Marble industrial area. Lastly, careful quarry development planning is important both for enhancing LCA and for improving production processes through sustainable technologies that yield green label products meeting environmental performance standards.  相似文献   
50.
The goal of ecosystem-based management (EBM) is to support a sustainable and holistic multisectored management approach, and is recognized in a number of international policy frameworks. However, it remains unknown how these goals should be linked to assessments and management plans for marine fauna, such as mammals and fish stocks. It appears particularly challenging to carry out trade-off analyses of various ocean uses without a framework that integrates knowledge of environmental, social, and economic benefits derived from nonstationary marine fauna. We argue this gap can be filled by applying a version of the ecosystem-service approach at the population level of marine fauna. To advance this idea, we used marine mammals as a case study to demonstrate what indicators could operationalize relevant assessments and deliver an evidence base for the presence of ecosystem services and disservices derived from marine mammals. We found indicators covering common ecosystem service categories feasible to apply; examples of indicator data are already available in the literature for several populations. We encourage further exploration of this approach for application to marina fauna and biodiversity management, with the caveat that conceptual tensions related to the use of the ecosystem service concept itself needs to be addressed to ensure acceptance by relevant stakeholders.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号