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   869篇
  免费   5篇
  国内免费   9篇
安全科学   14篇
废物处理   24篇
环保管理   111篇
综合类   165篇
基础理论   178篇
环境理论   2篇
污染及防治   278篇
评价与监测   58篇
社会与环境   48篇
灾害及防治   5篇
  2023年   7篇
  2022年   18篇
  2021年   9篇
  2020年   11篇
  2019年   10篇
  2018年   28篇
  2017年   23篇
  2016年   62篇
  2015年   32篇
  2014年   51篇
  2013年   65篇
  2012年   53篇
  2011年   70篇
  2010年   39篇
  2009年   29篇
  2008年   56篇
  2007年   50篇
  2006年   39篇
  2005年   32篇
  2004年   38篇
  2003年   28篇
  2002年   26篇
  2001年   18篇
  2000年   10篇
  1999年   4篇
  1998年   5篇
  1997年   9篇
  1996年   8篇
  1995年   4篇
  1994年   7篇
  1993年   2篇
  1992年   3篇
  1991年   4篇
  1990年   4篇
  1989年   2篇
  1987年   1篇
  1986年   1篇
  1984年   1篇
  1983年   4篇
  1982年   3篇
  1981年   5篇
  1980年   2篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
  1973年   1篇
  1968年   1篇
  1961年   1篇
  1957年   1篇
  1952年   1篇
排序方式: 共有883条查询结果,搜索用时 31 毫秒
431.
432.
433.
Monitoring of amnesic shellfish poisoning (ASP) toxins in shellfish from the Catalan coast started in 2001. No ASP toxins were detected in any of the analyses performed before 2008. On 22 January 2008, domoic acid (DA) was detected in Donax trunculus (0.5 mg?kg?1) and confirmed by rapid resolution liquid chromatography–tandem mass spectrometry (0.6 mg?kg?1). A total of 974 shellfish samples were analyzed from January 2008 to December 2011, covering all the Catalan production areas and the most important marketed species. DA was detected in 23.8 % of the samples and was recorded every month in all areas and all species, except Ostrea edulis, although the percentage of samples with DA and DA content varied widely among samples. DA exceeded the regulatory level of 20 mg?kg?1 twice: in Callista chione sampled on February 2008 and in D. trunculus sampled on April 2010. DA content in Bolinus brandaris appeared constant and close to 4.5 mg?kg?1 for months in 2009. Mytilus galloprovincialis, Crassostrea gigas, and Ruditapes sp. presented very low concentrations of DA in the Ebro Delta bays, despite 113 alert situations according to Pseudo-nitzschia spp. abundances and the high number of shellfish samples analyzed. The origin of DA in Catalan shellfish remains unknown.  相似文献   
434.
435.
The transformation and transfer of nitrogen during the aerobic treatment of seven wastes were studied in ventilated air-tight 10-L reactors at 35 °C. Studied wastes included distinct types of organic wastes and their digestates. Ammonia emissions varied depending on the kind of waste and treatment conditions. These emissions accounted for 2–43% of the initial nitrogen. Total nitrogen losses, which resulted mainly from ammonia emissions and nitrification–denitrification, accounted for 1–76% of the initial nitrogen. Ammonification was the main process responsible for nitrogen losses. An equation which allows estimating the ammonification flow of each type of waste according to its biodegradable carbon and carbon/nitrogen ratio was proposed. As a consequence of the lower contribution of storage and leachate rates, stripping and nitrification rates of ammonia nitrogen were negatively correlated. This observation suggests the possibility of promotingnitrification in order to reduce ammonia emissions.  相似文献   
436.
Regional Environmental Change - This article proposes an innovative approach to assess the benefits of adapting to sea level rise (SLR) in a coastal area on a regional scale. The valuation...  相似文献   
437.
Intensive use of chlorinated pesticides from the 1960s to the 1990s has resulted in a diffuse contamination of soils and surface waters in the banana-producing areas of the French West Indies. The purpose of this research was, for the first time, to examine the degradation of two of these persistent pollutants – chlordecone (CLD) and beta-hexachlorocyclohexane (β-HCH) in 1 mg L?1 synthetic aqueous solutions by means of photolysis, (photo-) Fenton oxidation and ozonation processes. Fenton oxidation is not efficient for CLD and yields less than 15% reduction of β-HCH concentration in 5 h. Conversely, both molecules can be quantitatively converted under UV-Vis irradiation reaching 100% of degradation in 5 h, while combination with hydrogen peroxide and ferrous iron does not show any significant improvement except in high wavelength range (>280 nm). Ozonation exhibits comparable but lower degradation rates than UV processes. Preliminary identification of degradation products indicated that hydrochlordecone was formed during photo-Fenton oxidation of CLD, while for β-HCH the major product peak exhibited C3H3Cl2 as most abundant fragment.  相似文献   
438.
Despite early successes, the ‘zero-carbon homes’ agenda in England is being wound down. Ecological modernisation theory, which focuses on the way in which political, economic, and social forces interact with one other in the provision of environmental goods and services, is used to explain this. Existing literature on zero-carbon homes is fragmented, with scholars focusing on a range of social, economic, or political explanations. Ecological modernisation theory reconciles these various strands to produce a nuanced explanation for this agenda’s evolution. An ambitious but poorly defined legislative approach placed a burden on house-builders to meet compliance costs associated with zero-carbon, but framing sustainability economistically also led to considerable uncertainty. The 2008 financial crisis, the politicisation of housing, and the election of a government with a deregulatory mandate influenced the resilience of the policy agenda as private-sector actors exploited the uncertainty and political will in order to evade their policy burdens.  相似文献   
439.
Environmental stratifications provide the framework for efficient surveillance and monitoring of biodiversity and ecological resources, as well as modelling exercises. An obstacle for agricultural landscape monitoring in Estonia has been the lack of a framework for the objective selection of monitoring sites. This paper describes the construction and testing of the Environmental Stratification of Estonia (ESE). Principal components analysis was used to select the variables that capture the most amount of variation. Seven climate variables and topography were selected and subsequently subjected to the ISODATA clustering routine in order to produce relatively homogeneous environmental strata. The ESE contains eight strata, which have been described in terms of soil, land cover and climatic parameters. In order to assess the reliability of the stratification procedure for the selection of monitoring sites, the ESE was compared with the previous map of Landscape Regions of Estonia and correlated with five environmental data sets. All correlations were significant. The stratification has therefore already been used to extend the current series of samples in agricultural landscapes into a more statistically robust series of monitoring sites. The potential for applying climate change scenarios to assess the shifts in the strata and associated ecological impacts is also examined.  相似文献   
440.
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