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   743篇
  免费   1篇
  国内免费   9篇
安全科学   14篇
废物处理   16篇
环保管理   64篇
综合类   162篇
基础理论   145篇
环境理论   2篇
污染及防治   263篇
评价与监测   51篇
社会与环境   35篇
灾害及防治   1篇
  2023年   7篇
  2022年   19篇
  2021年   10篇
  2020年   9篇
  2019年   13篇
  2018年   22篇
  2017年   17篇
  2016年   50篇
  2015年   32篇
  2014年   46篇
  2013年   56篇
  2012年   48篇
  2011年   56篇
  2010年   28篇
  2009年   25篇
  2008年   44篇
  2007年   42篇
  2006年   33篇
  2005年   27篇
  2004年   30篇
  2003年   25篇
  2002年   19篇
  2001年   16篇
  2000年   8篇
  1999年   2篇
  1998年   3篇
  1997年   6篇
  1996年   5篇
  1995年   4篇
  1994年   4篇
  1993年   2篇
  1992年   3篇
  1991年   3篇
  1990年   3篇
  1983年   4篇
  1982年   3篇
  1981年   2篇
  1980年   2篇
  1977年   2篇
  1973年   1篇
  1972年   1篇
  1968年   1篇
  1967年   3篇
  1961年   1篇
  1955年   1篇
  1954年   1篇
  1953年   2篇
  1952年   1篇
  1950年   1篇
  1913年   1篇
排序方式: 共有753条查询结果,搜索用时 234 毫秒
381.
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   
382.
383.
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   
384.
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   
385.
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   
386.
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   
387.
388.
The purpose of our study is to assess the effect of chlorpyrifos (CPF) on rat cerebral and cerebellar maturity during the suckling period. Female Wistar rats were given 0.2?g?L?1 of CPF in drinking water, equivalent to 40?mg?kg?1 of body weight?day?1, from day zero until day ten after delivery. In treated pups, plasma butyrylcholinesterase (BuChE) activity was inhibited by 70%. Cerebrum and cerebellum acetyl-cholinesterase (AchE) activities were reduced by 71 and 75%, respectively. The results suggest that CPF was distributed in pup tissues through the milk of lactating mothers, resulting in inhibition of AchE activities. At age 10 days, the CPF-treated pups showed a 28% decrease in body weight, a 23 and 41% decrease in plasma free T3 and T4 levels and reduction in cerebral and cerebellar protein content by 36 and 38%, respectively. Consistent histological changes were found in the cerebellum of CPF treated pups, with the external granular layer being markedly developed, the Purkinje cell bodies being poorly differentiated and abnormally distributed into the internal granular layer.  相似文献   
389.
Natural resource governance is by nature multi-level, mobilizing various multi-stakeholder arenas in which a social learning approach may play a role. An approach using simulation tools such as role-playing games was tested in metropolitan areas of two South American cities: (1) in the periphery of Cochabamba, to facilitate conflict resolution stemming from the impact of urbanization on the irrigation infrastructure, and (2) in peri-urban areas of São Paulo, to assist in negotiations on land and water management in a protected catchment. Both interventions were designed to broaden the stakeholders' perspectives and facilitate the exchange of the views of different actors on water and land management using role-playing games. This paper discusses how the scale strategy embedded in the tools and in the mode of participation in fact constrained the possibility of bridging the gap between organisational levels in both situations. This calls for both the crafting of multi-level approaches able to take different levels into account, and finding adequate bridging mechanisms to enhance the integration of learning within organisations and communities.  相似文献   
390.
Summary

The Ecological Footprint (EF) is a method for estimating the biologically productive area necessary to support current consumption patterns, given prevailing technical and economic processes. By comparing human impact with the planet's limited bioproductive area. this method tests a basic ecological condition for sustainability. The ecological footprint has gained popularity for its pedagogical strength as it expresses the results of its analysis in spatial units that can easily be communicated. Many EF estimates have been performed on a global, national and sulrnationallevel. In this paper. we review the method and critically assess it from a sustainability perspective based on first order principles. We examine: ? Which aspects of sustainability are already covered by existing EF assessments;

? Which further aspects ofsustainability could be made accountable through the EF (such as areas needed to assimilate waste streams that are not yet accounted for in present assessments); and

? Those aspects ofsustainability that cannot be accountable through the EF. Thereby needing complimentary auditing tools.

Since the EF is a measure of renewable biocapacity, we argue that some dimensions of ecological sustainability should not be included in the EF. These include human activities that should be phased out to obtain sustainability, such as emissions of persistent compounds foreign to nature and qualitative aspects that represent secondary uses of ecological areas and do not, therefore, occupy a clearly identifiable additional ecological space. We also conclude that the EF is useful for documenting the overall human use or abuse of the potentially renewable functions and services of nature. Particularly, by aggregating in a consistentway a varity of human impacts, it can effectively identify the scale of the human economy by companson with the size of the biosphere.  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