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   157篇
  免费   3篇
  国内免费   2篇
废物处理   9篇
环保管理   13篇
综合类   29篇
基础理论   28篇
环境理论   1篇
污染及防治   53篇
评价与监测   19篇
社会与环境   8篇
灾害及防治   2篇
  2023年   6篇
  2022年   4篇
  2021年   8篇
  2020年   2篇
  2019年   2篇
  2018年   7篇
  2017年   6篇
  2016年   7篇
  2015年   7篇
  2014年   5篇
  2013年   18篇
  2012年   10篇
  2011年   12篇
  2010年   5篇
  2009年   13篇
  2008年   9篇
  2007年   11篇
  2006年   8篇
  2005年   1篇
  2004年   6篇
  2003年   5篇
  2002年   2篇
  2000年   2篇
  1995年   1篇
  1994年   1篇
  1992年   3篇
  1979年   1篇
排序方式: 共有162条查询结果,搜索用时 140 毫秒
81.
A new HPLC method was developed for the simultaneous determination of aminophenol isomers by means of a mixed-mode stationary phase containing both SCX and C18 moieties. All factors influencing the separation were discussed and optimized. The chromatographic conditions for the separation of aminophenols are the stationary phase duet SCX/C18, the mobile phase of aqueous phosphate buffer (pH 4.85):methanol?=?85:15 (v/v) delivered with a flow rate of 1 mL/min and a detection at 285 nm. The method proposed was validated in terms of linearity, limits of detection and quantification, accuracy and precision. The HPLC method elaborated here was applied with good results on river water samples. In order to survey the quality of surface rivers entered in treatment plants which deliver water for Bucharest, two major rivers were included in a monitoring program which last more than 1 year.  相似文献   
82.
The aim of this in vitro study was to examine the secretion activity, markers of proliferation and apoptosis in porcine ovarian granulosa cells (GCs) after deoxynivalenol (DON) addition. Ovarian granulosa cells were incubated with DON for 24h: 10, 100 and 1000 ng/mL, while the control group received no DON. The secretion of insulin-like growth factor I (IGF-I) and progesterone was determined by radioimmunoassay (RIA) and expression of cyclin B1, PCNA and caspase-3 by immunocytochemistry. IGF-I release by GCs was inhibited by DON, while progesterone release and the expression of cyclin B1 was stimulated by DON (at 1000 ng/mL but not at 10 and 100 ng/mL). PCNA expression was stimulated by DON (at 100 and 1000 ng/mL but not at 10 ng/mL). Caspase-3 expression was not influenced by DON treatment (at all doses). In conclusion, our results indicate, (1) a direct effect of DON on secretion of growth factor IGF-I and steroid hormone progesterone, (2) expression of markers of proliferation (cyclin B1 and PCNA) but not on the (3) expression of marker of apoptosis (caspase-3) in porcine ovarian granulosa cells. This in vitro study suggests the dose-dependent association of DON on porcine ovarian functions.  相似文献   
83.
To preserve the quality of surface water, official French regulations require farmers to keep a minimum acreage of grassland, especially bordering rivers. These agro-environmental measures do not account for the circulation of water within the catchment. This paper examines whether it is possible to design with the farmers agri-environmental measures at field and catchment scale to prevent soil erosion and surface water pollution. To support this participatory approach, the hydrology and erosion model STREAM was used for assessing the impact of a spring stormy event on surface runoff and sediment yield with various management scenarios. The study was carried out in collaboration with an agricultural committee in an area of south-western France where erosive runoff has a major impact on the quality of surface water. Two sites (A and B) were chosen with farmers to discuss ways of reducing total surface runoff and sediment yield at each site. The STREAM model was used to assess surface runoff and sediment yield under current cropping pattern at each site and to evaluate management scenarios including grass strips implementation or changes in cropping patterns within the catchment. The results of STREAM simulations were analysed jointly by farmers and researchers. Moreover, the farmers discussed each scenario in terms of its technical and economical feasibility. STREAM simulations showed that a 40 mm spring rainfall with current cropping patterns led to 3116 m3 total water runoff and 335 metric tons of sediment yield at site A, and 3249 m3 and 241 metric tons at site B. Grass strips implementation could reduce runoff for about 40% and sediment yield for about 50% at site A. At site B, grass strips could reduce runoff and sediment yield for more than 50%, but changes in cropping pattern could reduce it almost totally. The simulations led to three main results: (i) grass strips along rivers and ditches prevented soil sediments from entering the surface water but did not reduce soil losses, (ii) crop redistribution within the catchment was as efficient as planting grass strips, and (iii) efficient management of erosive runoff required coordination between all the farmers using the same watershed. This study shown that STREAM model was a useful support for farmers' discussions about how to manage runoff and sediment yield in their fields.  相似文献   
84.
化学物质水体归趋与影响 (简称CAFE)数据库是一个允许快速并无限制访问数据的集中式数据库。CAFE将现有的32 377种化学物质的归趋数据和4 498种化学物质的毒性效果数据整合至用户友好的工具中,以物种敏感度分布(SSD)的形式总结毒性数据,并提供了相关的1%和5%危害浓度(HC1和HC5)。为探究CAFE数据与报道的化学事故之间的联系,一项数据可用性评估显示,2000年至2014年间在美国国家应急中心呈报的55种化学物质中,32种物质的归趋和20种物质的毒性在CAFE中均有记录;2003年至2014年间由美国海洋及大气管理局呈报的205种化学物质中,86种物质的归趋和103种物质的毒性在CAFE中也均有记录。我们假设2种化学物质在环境中溢出(丙烯腈,溢出量为625桶 ;变性乙醇,溢出量为857桶),根据模型对其环境浓度进行模拟,进而说明CAFE在实际中的应用。在24 h时程的SSD中,大多数物种很可能分别在溢出后最初的35 min内和15 h内受到丙烯腈和变性酒精的影响。丙烯腈浓度在溢出后45 min已低于HC5(17 mg?LL-1),变性酒精浓度在溢出后60 h已低于HC5(2 676 mg?LL-1)。将100种化学物质以CAFE数据为基础得出的HC5与发表的HC5进行对比,我们发现超过一半的数值都在2倍差异以内,较少的一部分数值则超过了10倍差异。CAFE的发展提高了获取相关环境信息的能力,并可能应用于水体环境污染物溢出分析之外的更多领域。
精选自Adriana C. Bejarano, James K. Farr, Polly Jenne, Valerie Chu, Al Hielscher. The chemical aquatic fate and effects database (CAFE), a tool that supports assessments of chemical spills in aquatic environments. Environmental Toxicology and Chemistry: Volume 35, Issue 7, pages 1576–1586, July 2016. DOI: 10.1002/etc.3289
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3289/full
  相似文献   
85.
The issue of variances of different soil variables prevailing at different sampling scales is addressed. This topic is relevant for soil science, agronomy and landscape ecology. In multi-stage sampling there are randomness components in each stage of sampling which can be taken into account by introducing random effects in analysis through the use of hierarchical linear mixed models (HLMM). Due to the nested sampling scheme, there are several hierarchical sub-models. The selection of the best model can be carried out through likelihood ratio tests (LRTs) or Wald tests, which are asymptotically equivalent under standard conditions. However, when the comparison leads to a restricted hypothesis of variance components, standard conditions are not maintained, which leads to more elaborated versions of LRTs. These versions are not disseminated among environmental scientists. The present study shows the modeling of soil data from a sampling where sites, fields within sites, transects within fields, and sampling points within transects were selected in order to take samples from different vegetation types (open and shade). For soil data, several sub-models were compared using Wald tests, classic LRTs and adjusted LRTs where the distribution of the test statistic under the null hypothesis is the Chi-square mixture of Chi-square distributions. The inclusion of random effects via HLMM and suggested by the latest version of LRT allowed us to detect effects of vegetation type on soil properties that were not detected under a classical ANOVA.  相似文献   
86.
Environmental lead contamination in Uruguay became a matter of public concern in 2001, when cases of children with blood lead levels (BLL) higher than 20 μg/dl appeared in some low-income neighborhoods of Montevideo, being 10 μg/dl the intervention reference BLL. The aim of this paper is to show the results of multidisciplinary actions taken by decisions makers in social, environmental and healthcare aspects, to minimize lead exposure risks. We evaluated changes in blood lead levels of different children and non-exposed adult populations before and after the actions were taken, from 2001 on. For children populations and non-exposed adults, we found a significant decrease of almost 50% in BLL compared with studies done before the actions were taken. The main action to consider was the phasing out process of leaded gasoline in our country among other. We conclude that the integration of inter and multidisciplinary actions promoted was of high impact on the population, bringing about a public sensitization and growing awareness of the lead environmental risks.  相似文献   
87.
Stakeholders are increasingly involved in species conservation. We sought to understand what features of a participatory conservation program are associated with its ecological and social outcomes. We conducted a case study of the management of invasive vertebrates in Australia. Invasive vertebrates are a substantial threat to Australia's native species, and stakeholder participation in their management is often necessary for their control. First, we identified potential influences on the ecological and social outcomes of species conservation programs from the literature. We used this information to devise an interview questionnaire, which we administered to managers of 34 participatory invasive-vertebrate programs. Effects of invasive species were related to program initiator (agency or citizen), reasons for use of a participatory approach, and stakeholder composition. Program initiator was also related to the participation methods used, level of governance (i.e., governed by an agency or citizens), changes in stakeholder interactions, and changes in abundance of invasive species. Ecological and social outcomes were related to changes in abundance of invasive species and stakeholder satisfaction. We identified relations between changes in the number of participants, stakeholder satisfaction, and occurrence of conflict. Potential ways to achieve ecological and social goals include provision of governmental support (e.g., funding) to stakeholders and minimization of gaps in representation of stakeholder groups or individuals to, for example, increase conflict mitigation. Our findings provide guidance for increasing the probability of achieving ecological and social objectives in management of invasive vertebrates and may be applicable to other participatory conservation programs.  相似文献   
88.
This paper explores sovereign risk preferences against direct and indirect natural disasters losses in industrialized countries. Using Australia as a case study, the analysis compares expected disaster losses and government capacity to finance losses. Utilizing a national disaster loss dataset, extreme value theory is applied to estimate an all-hazard annual loss distribution. Unusually but critically, the dataset includes direct as well as indirect losses, allowing for the analysis to consider the oft-ignored issue of indirect losses. Expected annual losses (direct, and direct plus indirect) are overlaid with a risk-layer approach, to distinguish low, medium and extreme loss events. Each risk layer is compared to available fiscal resources for financing losses, grounded in the political reality of Australian disaster financing. When considering direct losses only, we find support for a risk-neutral preference on the part of the Australian government for low and medium loss levels, and a risk-averse preference in regard to extreme losses. When indirect losses are also estimated, we find that even medium loss levels are expected to overwhelm available fiscal resources, thereby violating the available resources assumption underlying arguments for sovereign risk neutrality. Our analysis provides empirical support for the assertion that indirect losses are a major, under-recognised concern for industrialized countries. A risk-averse preference in regard to medium and extreme loss events recommends enhanced investment in both corrective and prospective risk reduction in relation to these risks level, in particular to reduce indirect losses.  相似文献   
89.
Journal of Material Cycles and Waste Management - The substitution of standard clays to residues, in this case copper smelter slag and fly ashes coming from the incineration process of MSW in...  相似文献   
90.
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