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   708篇
  免费   17篇
  国内免费   11篇
安全科学   12篇
废物处理   57篇
环保管理   63篇
综合类   81篇
基础理论   153篇
污染及防治   266篇
评价与监测   59篇
社会与环境   41篇
灾害及防治   4篇
  2023年   9篇
  2022年   45篇
  2021年   36篇
  2020年   12篇
  2019年   16篇
  2018年   36篇
  2017年   35篇
  2016年   50篇
  2015年   36篇
  2014年   52篇
  2013年   67篇
  2012年   52篇
  2011年   48篇
  2010年   32篇
  2009年   32篇
  2008年   46篇
  2007年   28篇
  2006年   28篇
  2005年   12篇
  2004年   15篇
  2003年   13篇
  2002年   10篇
  2001年   7篇
  2000年   1篇
  1999年   4篇
  1998年   2篇
  1997年   1篇
  1996年   3篇
  1995年   3篇
  1994年   1篇
  1991年   1篇
  1984年   1篇
  1957年   1篇
  1956年   1篇
排序方式: 共有736条查询结果,搜索用时 296 毫秒
641.
Local initiatives and adaptation to climate change   总被引:1,自引:0,他引:1  
Blanco AV 《Disasters》2006,30(1):140-147
Climate change is expected to lead to an increase in the number and strength of natural hazards produced by climatic events. This paper presents some examples of the experiences of community-based organisations (CBOs) and non-governmental organisations (NGOs) of variations in climate, and looks at how they have incorporated their findings into the design and implementation of local adaptation strategies. Local organisations integrate climate change and climatic hazards into the design and development of their projects as a means of adapting to their new climatic situation. Projects designed to boost the resilience of local livelihoods are good examples of local adaptation strategies. To upscale these adaptation initiatives, there is a need to improve information exchange between CBOs, NGOs and academia. Moreover, there is a need to bridge the gap between scientific and local knowledge in order to create projects capable of withstanding stronger natural hazards.  相似文献   
642.
Quantitative and qualitative changes in organic matter were studied at different stages of treatment in a bioreactor designed to process leachates from a municipal solid waste landfill. The particulate matter (PM) and macromolecular fractions of the dissolved organic matter with solubility properties comparable to humic (acid-insoluble) and fulvic (acid-soluble) acid fractions (AI, AS, respectively) from the incoming black liquid, the bioreactor content, and the final processed effluent were isolated, quantified, and characterized by visible and infrared (IR) spectroscopies. The macromolecular signature either aliphatic (glycopeptides, carbohydrates) or aromatic (coinciding with infrared patterns of lignin, tannins etc.) enabled us to characterize the different organic fractions during the course of microbial transformation. The results reveal significant changes in the nitrogen speciation patterns within the different organic fractions isolated from the wastewater. The final increase in the relative proportions of nitrogen in the least aromatic AS fraction during microbial transformation could be related to protein formation inside the bioreactor. After biological treatment and ultrafiltration, the amount of organic matter was reduced by approximately 70%, whereas aromaticity increased in all fractions, indicating preferential elimination of aliphatic wastewater compounds. Most of the remaining fractions at the end of the process consisted of a yellow residue rich in low molecular weight AS fractions.  相似文献   
643.
Spatial planning typically involves multiple stakeholders. To any specific planning problem, stakeholders often bring different levels of knowledge about the components of the problem and make assumptions, reflecting their individual experiences, that yield conflicting views about desirable planning outcomes. Consequently, stakeholders need to learn about the likely outcomes that result from their stated preferences; this learning can be supported through enhanced access to information, increased public participation in spatial decision-making and support for distributed collaboration amongst planners, stakeholders and the public. This paper presents a conceptual system framework for web-based GIS that supports public participation in collaborative planning. The framework combines an information area, a Multi-Criteria Spatial Decision Support System (MC-SDSS) and an argumentation map to support distributed and asynchronous collaboration in spatial planning. After analysing the novel aspects of this framework, the paper describes its implementation, as a proof of concept, in a system for Web-based Participatory Wind Energy Planning (WePWEP). Details are provided on the specific implementation of each of WePWEP's four tiers, including technical and structural aspects. Throughout the paper, particular emphasis is placed on the need to support user learning throughout the planning process.  相似文献   
644.
An adaptation of the Drivers-Pressure-State-Impact-Response methodology is presented in this work. The differential DPSIR (ΔDPSIR) was developed to evaluate impacts on the coastal environment and as a tool for integrated ecosystem management. The aim of the ΔDPSIR is to provide scientifically-based information required by managers and decision-makers to evaluate previously adopted policies, as well as future response scenarios. The innovation of the present approach is to provide an explicit link between ecological and economic information related to the use and management of a coastal ecosystem within a specific timeframe. The application of ΔDPSIR is illustrated through an analysis of developments in a Southwest European coastal lagoon between 1985 and 1995. The value of economic activities dependent on the lagoon suffered a significant reduction (ca. −60%) over that period, mainly due to a decrease in bivalve production. During that decade the pressures from the catchment area were managed (ca. 176 million Euros), mainly through the building of waste water treatment plants. Notwithstanding this, the ecosystem state worsened with respect to abnormal clam mortalities due to a parasite infection and to benthic eutrophication symptoms in specific problematic areas. The negative economic impacts during the decade were estimated between −565 and −315 million Euros, of which 9–49% represent the cost of environmental externalities. Evaluation of these past events indicates that future management actions should focus on reducing the limitation on local clam seeds, which should result in positive impacts to both the local socio-economy and biodiversity.  相似文献   
645.
The effect of the addition of spent grape marc compost (GMC) and vermicompost (GMV) as amendments to slate mining wastes was evaluated in a laboratory incubation experiment. Mixtures of slate processing fines (SPF), with three doses of each amendment (4%, 8% and 16% compost, dry weight), plus a control were incubated at 25 degrees C in the laboratory for 90 days. The changes in the chemical and biological properties of the mixtures (pH, total C, total N, inorganic N, available nutrients, microbial biomass carbon and dehydrogenase activity) were investigated during the incubation period, and once it was finished, the phytotoxicity of the mixtures was determined by the germination of Lolium multiflorum Lam. seeds. The addition of the amendments significantly increased the nutrient concentrations of the SPF and enhanced biological activity by increasing microbial biomass and enzymatic activity. Results improved with higher doses; within the composts, GMV showed a better performance than GMC. These results prove the suitability of grape marc-derived amendments for the biochemical amelioration of mining wastes, and highlight the benefits of organic amendment in restoration projects.  相似文献   
646.
Stone provisioning is a nest-maintenance activity accomplished by pygoscelid penguins after reliefs during the incubation/brooding period. The functional significance of this behaviour has been mainly explained as a parental strategy preventing nest flooding under detrimental weather conditions. In addition, and in the light of recent studies, this behaviour could also fit into the sexual selection process. In this study, we tested the first idea, that is, whether stone provisioning is a nest-maintenance behaviour to increase egg/nestling survival by lowering the risk of nest flooding, and can thus be considered a form of parental care. Additionally, we investigated if the effort invested by parents in nest maintenance is constrained by physiologically limiting resources. The effort of stone collection and the perceived risk of nest flooding were experimentally manipulated during the incubation and early brooding phases in a chinstrap penguin, Pygoscelis antarctica, colony. Three groups of nests were established. After weighing, control nests were left unmanipulated. In a second group of nests (reduced group), only one-half of the initial weight of stones was returned to the nests. In a third group of nests (snow-added group), we both reduced nest weight by a half and added snow outside the nest bowl over 6 consecutive days. Ten days after manipulation, the difference in nest weight between initial and final conditions was significantly related to treatment: penguins increased stone provisioning in the reduced group (44% of half-reduced nests), but drastically more in the reduced and snow-added group (123% of half-reduced nests), while the weight of control nests was unchanged compared to premanipulation conditions. The intensity of stone provisioning was affected by nest date, peaking about hatching time and shortly after, and declining with advancing chick age. These results suggest that stone provisioning is a mechanism that has evolved to prevent egg or chick mortality by nest flooding. The haematocrit, but not leukocyte numbers as expressed by the buffy coat layer, varied with the experimental conditions. Penguins investing more time in nest maintenance had a lower haematocrit, suggesting a physiological trade-off probably mediated by competition between the time devoted to nest maintenance versus foraging activities. The amount of stones collected and the haematocrit were positively related to the number of neighbour nests, so those individuals surrounded by more nests seemed to obtain benefits in the availability of nest material and energy savings. This study indicates that stone-provisioning behaviour is a nest-maintenance activity evolved to improve thermal nest characteristics potentially increasing offspring survival, and competing in time and energy with other reproductive activities. Stone provisioning in penguins should therefore be regarded as a form of parental care and an important part of individual reproductive effort in species breeding in harsh environments. Furthermore, nest size and nest-maintenance effort should be considered reproductive traits indicative of parental quality and thus could also be involved in the post-mating sexual selection process.  相似文献   
647.
Sodium monofluoroacetate (compound 1080) is one of the most potent pesticides. It is also a metabolite of many other fluorinated compounds, including anticancer agents, narcotic analgesics, pesticides or industrial chemicals. Other sources of water contamination are the atmospheric degradation of hydrofluorocarbons and hydrochlorofluorocarbons. However, there is little information available about the adverse effects of sodium fluoroacetate in aquatic organisms. Firstly, the bacterium Vibrio fischeri (decomposer), the alga Chlorella vulgaris (1st producer) and the cladoceran Daphnia magna (1st consumer) were used for the ecotoxicological evaluation of SMFA. The most sensitive models were C. vulgaris and D. magna, with a NOAEL of 0.1 and an EC50 of 0.5 mM at 72 h, respectively. According to the results after the acute exposure and due to its high biodegradation rate and low bioaccumulation potential, sodium fluoroacetate is most unlikely to produce deleterious effects to aquatic organisms. Secondly, two fish cell lines were employed to investigate the effects and mechanisms of toxicity in tissues from 2nd consumers. The hepatoma fish cell line PLHC-1 was more sensitive to SMFA than the fibroblast-like fish cell line RTG-2, being the uptake of neutral red the most sensitive bioindicator. Lysosomal function, succinate dehydrogenase and acetylcholinesterase activities were inhibited, glucose-6-phosphate dehydrogenase activity was particularly stimulated, and metallothionein and ethoxyresorufin-O-deethylase levels were not modified. Intense hydropic degeneration, macrovesicular steatosis and death mainly by necrosis but also by apoptosis were observed. Moreover, sulphydryl groups and oxidative stress could be involved in PLHC-1 cell death induced by SMFA more than changes in calcium homeostasis.  相似文献   
648.
Fish, sediment and water samples from different places along the Spanish River Vero, a tributary of the Cinca River in the Ebro River basin, were collected in two different sampling campaigns, the first one during November 2004 and the second one in November 2005. The samples were collected up- and downstream from an industrial park. A total of 29 fishes, 6 sediments and 3 water samples were analyzed for polybrominated diphenyl ethers (PBDEs). Analytical work included 23 congeners, from tri- to deca-BDEs. The highest values for both sediment and fish samples were found downstream of the industrial park. High BDE-209 contamination was found in these sediment samples, with values up to 12 microg g(-1) dry weight. Moreover, BDE-209 was detected in 14 out of 15 biota samples collected downstream the industrial park, at concentration levels ranging from 20 to 707 ng g(-1) lipid weight, whereas it was not detected in samples collected upstream. These fish concentrations proved the bioavailability of BDE-209 and represented the highest deca-BDE values found in aquatic biota. The analysis of industrial effluents revealed that some industries contribute in some way to the BDE-209 contamination found in this area, but the industry focused on the polyamide polymerization is the main responsible.  相似文献   
649.
650.
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