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   212篇
  免费   2篇
  国内免费   6篇
安全科学   8篇
废物处理   15篇
环保管理   21篇
综合类   40篇
基础理论   45篇
污染及防治   73篇
评价与监测   13篇
社会与环境   5篇
  2024年   1篇
  2023年   1篇
  2022年   2篇
  2021年   2篇
  2020年   2篇
  2019年   2篇
  2018年   4篇
  2017年   3篇
  2016年   6篇
  2015年   4篇
  2014年   8篇
  2013年   26篇
  2012年   9篇
  2011年   18篇
  2010年   6篇
  2009年   9篇
  2008年   17篇
  2007年   22篇
  2006年   13篇
  2005年   7篇
  2004年   7篇
  2003年   5篇
  2002年   5篇
  2001年   5篇
  2000年   6篇
  1999年   3篇
  1998年   3篇
  1997年   5篇
  1996年   4篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1991年   4篇
  1989年   2篇
  1988年   1篇
  1987年   1篇
  1985年   1篇
  1983年   1篇
排序方式: 共有220条查询结果,搜索用时 31 毫秒
71.
In this article, we review the virology, pathology, epidemiology and clinical spectrum of intrauterine human parvovirus B19 (B19V) infection, including intrauterine fetal death, non-immune hydrops fetalis, thrombocytopenia and neurological manifestations such as pediatric stroke and perivascular calcifications. In addition, we discuss the new insights into the neurodevelopmental outcome of intrauterine B19V infection. Current diagnosis and management of B19V infection is summarized, including a diagnostic and follow-up flowchart for practical clinical use. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
72.
The objective of this article was to assess flood vulnerability based on the representative concentration pathways (RCP) scenarios at city and county levels. A quantile mapping method was adopted to correct bias that is inherent in climate change scenarios. A series of proxy variables related to climate exposure, sensitivity, and adaptive capacity were chosen to assess flood vulnerability. Proxy variables were standardized using the Z‐score method. Principal component analysis was carried out to calculate the weighting of proxy variables. The study area was the Korean peninsula. The spatial resolution was on a city and county basis and the temporal resolution was 1990s, 2025s, 2055s, and 2085s (divided into 1976‐2005, 2011‐2040, 2041‐2070, and 2071‐2100). In the spatial comparison, we found that the areas with high‐level flood vulnerability increased over time in the central region, including metropolitan areas, and near the southern coast. In the temporal comparison, we found that the RCP4.5 scenario showed a tendency to increase steadily and the RCP8.5 scenario showed a tendency to decrease in the 2055s slightly and increase again in the 2085s. The study findings may provide useful data for the determination of priority for countermeasure development, though robustness of these findings with additional future projections should be established.  相似文献   
73.
In order to characterize the status of indoor air pollution in some important facilities, a list of key criteria pollutants [particulate matter (PM(10)), carbon dioxide (CO(2)), carbon monoxide (CO), formaldehyde (HCHO), and bioaerosol] was measured from a total of 91 randomly selected sites in 18 different cities, Korea (February 2006 to December 2009). The target facilities include 43 child care facilities, 38 medical facilities, 6 elementary schools, and 4 postnatal care centers. The results showed that some air pollutants (e.g., CO and HCHO) did not exceed the recommended guideline [e.g., the Korean indoor air standard (KIAS) values of 10 ppm and 100 ppb, respectively]. However, concentration of PM(10), CO(2), and bioaerosol occasionally exceeded their respective guidelines (e.g., seven, three, and two cases). Discrete seasonalities were observed from indoor pollutants because of varying ventilation practice (e.g., summer time dominance of PM(10), HCHO, and bioaerosol or winter dominance of CO(2) and CO). However, as the concentrations of the indoor pollutants were scarcely above the recommended guideline level, more diversified approaches are desirable to diagnose the status of indoor pollution and to provide a realistic strategy for the improvement of IAQ.  相似文献   
74.
In this paper, a simulation model is presented for nutrient cycling in heathland ecosystems. The results of simulations are compared with field data of phosphorus and nitrogen accumulation in different compartments of the system in the years after burning, given in the literature on this subject (Chapman, 1967; 1970). It is shown that for the cycling of P the system returns slowly to equilibrium after an initial disturbance. The time span of about 30 years that is required to reach equilibrium is in agreement with the field data. However, P accumulation in living above-ground biomass and litter is overestimated by the model in the first years after burning. Nitrogen accumulation in biomass and litter is systematically underestimated by the model.The results are discussed with reference to the processes in nutrient cycling that are insufficiently understood, and with reference to the management of heathlands.  相似文献   
75.
76.
Future climate change is a source of growing concerns for the supply of energy and resources, and it may have significant impacts on industry and the economy. Major effects are likely to arise from changes to the freshwater resources system, due to the connection of energy generation to these water systems. Using future climate data downscaled by a stochastic weather generator, this study investigates the potential impacts of climate change on long‐term reservoir operations at the Chungju multipurpose dam in South Korea, specifically considering the reliability of the supply of water and hydropower. A reservoir model, Hydrologic Engineering Center‐Reservoir System Simulation (HEC‐ResSim), was used to simulate the ability of the dam to supply water and hydropower under different conditions. The hydrologic model Soil and Water Assessment Tool was used to determine the HEC‐ResSim boundary conditions, including daily dam inflow from the 6,642 km2 watershed into the 2.75 Gm3 capacity reservoir. Projections of the future climate indicate that temperature and precipitation during 2070‐2099 (2080s) show an increase of +4.1°C and 19.4%, respectively, based on the baseline (1990‐2009). The results from the models suggest that, in the 2080s, the average annual water supply and hydropower production would change by +19.8 to +56.5% and by +33.9 to 92.3%, respectively. Model simulations suggest that under the new climatic conditions, the reliability of water and hydropower supply would be generally improved, as a consequence of increased dam inflow.  相似文献   
77.
Polycyclic aromatic hydrocarbon (PAH) concentrations and their risks in surface sediments (n = 35) collected from coastal and estuarine areas of the northern Bohai and Yellow Seas, China, were investigated in 2008. Total concentrations of PAHs ranged from 52.3 to 1,870.6 ng/g dry weight. The greatest concentrations were observed in the Dou River of Tangshan where waste water from small factories is discharged into the river without treatment. At other locations, municipal sewage was the primary contributor of PAHs. Regional differences in concentrations of PAHs in sediments are related to human activities. Concentrations of PAHs were significantly correlated with concentrations of organic carbon in sediments. The patterns of relative concentrations and types of PAHs observed and knowledge of the potential sources, as well as the results of a principal component analysis, are consistent with the primary sources of PAHs in sediments of the northern Bohai Sea and Yellow Sea, being derived from the high-temperature pyrolytic processes such as combustion of fossil fuel. While concentrations of PAHs at most locations did not exceed the effects range median stated by the numerical effect-based sediment quality guidelines of the United States, concentrations of PAHs at some locations were similar to or greater than the effects range low.  相似文献   
78.
This study evaluates the effect of air pollution caused by cement plants on nearby residential areas and performs an exposure assessment of particulate matter (PM) and total Cr, Cr6+, Pb, and Al. Further, the blood Cr levels of residents exposed to PM released by cement plants are also assessed. Nine buildings (eight residential and one elementary school building) close to cement plants were selected for this study, which were located in Pyeongtaek port, in west of Gyeonggi Province, South Korea. A total of 51 suspended particulate samples were collected at a flow rate of 2.0 L/min. Total Cr was more widely detected in residents’ houses and elementary schools. PM levels were higher at distances of 4.1 and 4.8 km than those at closer distances of 2.7 km. This was due to the influence of wind direction. The estimated mean blood level of Cr for the study participants was 3.80 μg/L, which is higher than levels estimated by other studies on Cr blood levels. Therefore, cement plants could cause an increase in total Cr and blood Cr levels in residential areas, and more continuous monitoring is necessary to better understand their impacts.  相似文献   
79.
80.
The potential environmental benefits of moving from a product-based economy to a functional economy involving greater use of services is a subject of increasing interest and debate in the field of eco-efficiency. This paper provides a typology and fuller analysis of eco-efficient producer services than hitherto reported. Three broad classes of service are described and assessed: product based including product results, product utility and product extension; electronic substitution and information based. Examples of each are drawn from a major study on the successes and barriers of eco-services in Europe. The paper concludes that while there are a number of areas of success, there are considerable barriers to wider development and uptake of such services, and that many of the more successful service applications are not necessarily driven by environmental considerations. The paper warns that the shift from products to services cannot be assumed to be eco-efficient and there are a number of rebound effects which need to be carefully analysed.  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