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   522篇
  免费   3篇
  国内免费   3篇
安全科学   13篇
废物处理   31篇
环保管理   21篇
综合类   115篇
基础理论   106篇
污染及防治   156篇
评价与监测   68篇
社会与环境   16篇
灾害及防治   2篇
  2023年   6篇
  2022年   18篇
  2021年   18篇
  2020年   12篇
  2019年   9篇
  2018年   22篇
  2017年   22篇
  2016年   32篇
  2015年   19篇
  2014年   34篇
  2013年   70篇
  2012年   39篇
  2011年   41篇
  2010年   28篇
  2009年   18篇
  2008年   13篇
  2007年   13篇
  2006年   13篇
  2005年   6篇
  2004年   4篇
  2003年   6篇
  2002年   5篇
  2000年   3篇
  1998年   2篇
  1996年   3篇
  1995年   3篇
  1991年   3篇
  1987年   3篇
  1983年   1篇
  1982年   5篇
  1979年   1篇
  1972年   1篇
  1971年   1篇
  1970年   1篇
  1968年   1篇
  1967年   3篇
  1966年   1篇
  1965年   2篇
  1964年   3篇
  1963年   1篇
  1961年   3篇
  1960年   4篇
  1959年   6篇
  1958年   10篇
  1957年   4篇
  1956年   6篇
  1955年   1篇
  1928年   1篇
  1920年   1篇
  1919年   1篇
排序方式: 共有528条查询结果,搜索用时 218 毫秒
431.
The occurrence and severity of harmful cyanobacterial or blue-green algal blooms (HABs) have increased in recent decades, posing a serious threat of illness to humans. In some countries, water contaminated with cyanotoxins that is used for drinking or haemodialysis has posed a particularly serious risk. However, it is now recognized that recreational exposure to natural toxins by skin contact, accidental swallowing of water or inhalation can also cause a wide range of acute or chronic illnesses. In this review, we focus on the importance of cyanotoxin management in recreational waters. The symptoms related with HAB poisonings, the recommended safety concentrations limit for cyanobacteria and cyanotoxins in such waters, as well as early health hazard indicators of their presence and their monitoring are all discussed. We also present in this review an overview of the methods developed in recent decades for eliminating cyanobacteria and the toxic compounds that they produce.  相似文献   
432.
Arsenic distribution in water/sediment system of Sevojno   总被引:1,自引:0,他引:1  
Arsenic is a toxic and carcinogenic element. Its toxicity depends on its oxidation state and its concentration. The aim of this paper is to determine, for the first time, the concentration levels of arsenic in water and sediment during the spring/summer period of 2009 in Sevojno, a region in West Serbia with a long industrial tradition, as well as to determine the model of arsenic distribution in water/sediment system and the level of its compatibility with the existing theoretical model. Adsorption is a continual process in the environment. It plays a very important role in the transport and fate of pollutants, especially in sediment. The adsorption of arsenic was examined using the Freundlich adsorption isotherm.  相似文献   
433.
Considering growing population and decreasing mineral resource reserves, the issue of undermining has been and shall remain very topical. This study aims to identify the mutual connections between mined out panels of a deposit and the final manifestations on the ground surface related to deep black coal mining. On the grounds of the identified connections, the study describes a method to simplify a common evaluation of undermined areas according to building site categories. Within the study, a demarcation of the areas was conducted in two localities in Czech Republic influenced by the effects of undermining in the Upper-Silesian Basin. In the allotment of the CSM Mine, an area unsuitable for founding structures was defined from the centre of the worked out workings to the distance of 175 m from the panel's edge, for which the corresponding break angle is 78.3°. Similarly, in the allotment of the Paskov Mine, an area unsuitable for founding structures was determined to the distance of 500 m from the panel's edge, for which the corresponding break angle is 50.2°. This demarcation may be implemented prior to deposit mining being aware of several physical-mechanical parameters of rocks in the deposit's overburden. Having mined out a particular section of a deposit, it is recommended to verify the values of break angle using the method described herein. The study may be applied as a relatively fast and effective method to evaluate future land use for planning.  相似文献   
434.
In this study, we investigated the relationships between stream water chemistry and watershed characteristics (topography—mean altitude and slope; climate—mean annual temperature and precipitation; geology—geochemical reactivity; land cover; inhabitation—population density, road density and number of municipalities). We analyzed the concentrations of the major anions (Cl, F, NO3, SO4, SiO2), cations (Ca, Mg, Na, K, Mn, Fe, Al), trace elements (Li, Sr, Cu), ABS245, TDP (total dissolved phosphorus), pH, and conductivity at 3,220 diverse watersheds covering a wide variety of watershed characteristics in the Czech Republic. We used marginal and partial multivariate analyses to reveal the most important variables. The partial analysis showed that only 14 % of the variance could be assigned to a specific factor and that 41 % of the variance is shared among the factors, which indicated complex interactions between the watershed characteristics.  相似文献   
435.
Environmental Geochemistry and Health - The aim of this study was to determine the influence of traffic density on air pollutant levels as well as to analyse the spatial and temporal distribution...  相似文献   
436.
437.
Environmental Science and Pollution Research - This study describes the development of tool for testing different policies for reduction of greenhouse gas (GHG) emissions in energy sector using...  相似文献   
438.
BiVO4/TiO2 composites with different weight ratios have been prepared by coprecipitation-based reactions followed by either thermal or hydrothermal treatment with the aim of evaluating the TiO2 photosensitization by BiVO4. The obtained materials present in all cases the desired monoclinic phase of BiVO4 and anatase phase of TiO2. Visible light absorption increased with increasing amount of bismuth vanadate. XPS results reveal the surface enrichment of Ti with respect to the bulk composition in samples characterised by a higher content of BiVO4. The photocatalytic activity of the prepared materials was tested for the degradation of isopropanol in the gas phase under indoor illumination conditions. Although none of the composites was able to improve the activity of TiO2, the low BiVO4 containing samples appear as more suitable for further synthesis tuning.  相似文献   
439.
440.
Research on trace elements and the effects of their ingestion on human health is often seen in scientific literature. However, little research has been done on the distribution of trace elements in the environment and their impact on health. This paper examines what characteristics among participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study are associated with levels of environmental exposure to arsenic, magnesium, mercury, and selenium. Demographic information from REGARDS participants was combined with trace element concentration data from the US Geochemical Survey (USGS). Each trace element was characterized as either low (magnesium and selenium) or high (arsenic and mercury) exposure. Associations between demographic characteristics and trace element concentrations were analyzed with unadjusted and adjusted logistic regression models. Individuals who reside in the Stroke Belt have lower odds of high exposure (4th quartile) to arsenic (OR 0.33, CI 0.31, 0.35) and increased exposure to mercury (OR 0.65, CI 0.62, 0.70) than those living outside of these areas, while the odds of low exposure to trace element concentrations were increased for magnesium (OR 5.48, CI 5.05, 5.95) and selenium (OR 2.37, CI 2.22, 2.54). We found an association between levels of trace elements in the environment and geographic region of residence, among other factors. Future studies are needed to further examine this association and determine whether or not these differences may be related to geographic variation in disease.  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