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   578篇
  免费   12篇
  国内免费   7篇
安全科学   14篇
废物处理   38篇
环保管理   42篇
综合类   65篇
基础理论   155篇
污染及防治   184篇
评价与监测   54篇
社会与环境   43篇
灾害及防治   2篇
  2023年   7篇
  2022年   20篇
  2021年   14篇
  2020年   8篇
  2019年   12篇
  2018年   26篇
  2017年   26篇
  2016年   34篇
  2015年   14篇
  2014年   32篇
  2013年   49篇
  2012年   42篇
  2011年   55篇
  2010年   34篇
  2009年   38篇
  2008年   29篇
  2007年   34篇
  2006年   24篇
  2005年   26篇
  2004年   16篇
  2003年   15篇
  2002年   4篇
  2001年   8篇
  2000年   9篇
  1999年   2篇
  1997年   3篇
  1996年   3篇
  1993年   3篇
  1992年   1篇
  1991年   3篇
  1990年   2篇
  1989年   1篇
  1988年   1篇
  1986年   1篇
  1972年   1篇
排序方式: 共有597条查询结果,搜索用时 15 毫秒
161.
The Common Agricultural Policy (CAP) is the European Union's main instrument for agricultural planning, with a new reform approved for 2023–2027. The CAP intends to align with the European Green Deal (EGD), a set of policy initiatives underpinning sustainable development and climate neutrality in the European Union (EU), but several flaws cast doubts about the compatibility of the objectives of these 2 policies. We reviewed recent literature on the potential of CAP environmental objectives for integration with the EGD: protection of biodiversity, climate change mitigation and adaptation, and sustainable management of natural resources. The CAP lacks appropriate planning measures, furthering instead risks to biodiversity and ecosystem services driven by landscape and biotic homogenization. Funding allocation mechanisms are not tailored to mitigate agricultural emissions, decreasing the efficiency of climate mitigation actions. The legislation subsidies farmers making extensive use of synthetic inputs without adequately supporting organic production, hindering the transition toward sustainable practices. We recommend proper control mechanisms be introduced in CAP Strategic Plans from each member state to ensure the EU is set on a sustainable production and consumption path. These include proportional assignment of funds to each CAP objective, quantitative targets to set goals and evidence-based interventions, and relevant indicators to facilitate effective monitoring of environmental performance. Both the CAP and the EGD should maintain ambitious environmental commitments in the face of crisis to avoid further degradation of the natural resources on which production systems stand.  相似文献   
162.
A common industrial solvent additive is 1,4‐dioxane. Contamination of dissolved 1,4‐dioxane in groundwater has been found to be recalcitrant to removal by conventional, low‐cost remedial technologies. Only costly labor and energy‐intensive pump‐and‐treat remedial options have been shown to be effective remedies. However, the capital and extended operation and maintenance costs render pump‐and‐treat technologies economically unfeasible at many sites. Furthermore, pump‐and‐treat approaches at remediation sites have frequently been proven over time to merely achieve containment rather than site closure. A major manufacturer in North Carolina was faced with the challenge of cleaning up 1,4‐dioxane and volatile organic compound–impacted soil and groundwater at its site. Significant costs associated with the application of conventional approaches to treating 1,4‐dioxane in groundwater led to an alternative analysis of emerging technologies. As a result of the success of the Accelerated Remediation Technologies, LLC (ART) In‐Well Technology at other sites impacted with recalcitrant compounds such as methyl tertiarybutyl ether, and the demonstrated success of efficient mass removal, an ART pilot test was conducted. The ART Technology combines in situ air stripping, air sparging, soil vapor extraction, enhanced bioremediation/oxidation, and dynamic subsurface groundwater circulation. Monitoring results from the pilot test show that 1,4‐dioxane concentrations were reduced by up to 90 percent in monitoring wells within 90 days. The removal rate of chlorinated compounds from one ART well exceeded the removal achieved by the multipoint soil vapor extraction/air sparging system by more than 80 times. © 2005 Wiley Periodicals, Inc.  相似文献   
163.
Environmental Science and Pollution Research - In the current study, water quality of five river sites in Parana River basin (Brazil), utilized for public water supply, was assessed through a set...  相似文献   
164.
- DOI: http://dx.doi.org/10.1065/espr2006.01.003 Background Water Quality Criteria were firstly defined in the 1970s by the EPA in the USA and the EIFAC in Europe, recognizing the need for protecting water quality in order to allow the use of water resources by man. In the 1990s, the European Commission emphasized the importance of safeguarding structure and function of biologic communities. These approaches were chemically-based. The European Water Framework Directive (WFD) substantially changes the concept of Water Quality, by assuming that a water body needs to be protected as an environmental good and not as a resource to be exploited. In this frame, the biological-ecological quality assumes a prevailing role. Main Features The Water Quality concept introduced by the WFD is a challenge for environmental sciences. Reference conditions should be defined for different typologies of water bodies and for different European ecoregions. Suitable indicators should be developed in order to quantify ecological status and to define what a 'good' ecological status is. Procedures should be developed for correlating the deviation from a good ecological to the effects of multiple stressors on function and structure of the ecosystem. The protection of biodiversity becomes a key objective. In this frame, the traditional procedures for ecotoxicological risk assessment, mainly based on laboratory testing, should be overcome by more site-specific approaches, taking into account the characteristics and the homeostatic capabilities of natural communities. In the paper an overview of the present knowledge and of the new trends in ecotoxicology to get these objectives will be given. A procedure is suggested based on the concept of Species Sensitivity Distribution (SSD). Recommendations and Perspective . The need for more site-specific and ecologically-oriented approaches in ecotoxicology is strongly recommended. The development of new tools for implementing the concept of 'Stress Ecology' has been recently proposed by van Straalen (2003). In the same time, more 'cological realism'is needed in practically applicable procedures for regulatory purposes.  相似文献   
165.
This work describes the nitration of aromatics upon near-UV photolysis of nitrate and nitrite in aqueous solution and upon photocatalytic oxidation of nitrite in TiO2 suspensions. Phenol is used in this work as a model aromatic molecule and as a probe for *NO2/N2O4. The photoinduced nitration of phenol in aqueous systems occurs upon the reaction between phenol and *NO2 or N2O4, and is enhanced by the photocatalytic oxidation of nitrite to *NO2 by TiO2. Aromatic photonitration in the liquid phase can play a relevant role in the formation of nitroaromatics in natural waters and atmospheric hydrometeors, thus being a potential pathway for the condensed-phase nitration of aromatics. Furthermore, the photoinduced oxidation of nitrite to nitrogen dioxide suggests a completely new role for nitrite in natural waters and atmospheric aerosols.  相似文献   
166.
Tarley CR  Arruda MA 《Chemosphere》2004,54(7):987-995
The morphological characteristics as well as chemical composition of rice husks were evaluated by different techniques such as spectroscopy and thermogravimetry. The material, which is considered a by-product obtained from rice milling, was then investigated as a potential decontaminant of toxic heavy metals present in laboratory effluents. Studies using glass columns were carried out at room temperature employing 100 ml of synthetic solutions containing Cd(II) and Pb(II) at 100 mg l(-1) in order to study the effects of pH, flow rate and particle size on Cd(II) and Pb(II) adsorption. After establishing the optimised conditions, the potentiality of rice husks for removing Cd(II) and Pb(II) ions from 100 ml of laboratory effluent, presenting concentrations before treatment of 22 and 12 mg l(-1), respectively, was evaluated. The ability to take up other metals species, such as Al(III), Cu(II) and Zn(II), present in this effluent was also studied. According to the data obtained, under the optimised conditions (pH=4.0, flow rate of 8.0 ml min(-1) and < or =355 microm rice husk particle size), 30 g of husks were necessary to attain the permissible limits for effluent release, as recommend by the EPA, for those species evolved in this work (Al, Cd, Cu, Pb and Zn).  相似文献   
167.
168.
Habitat loss and degradation are main global threats to biodiversity, and land-use changes in agriculture-dominated landscapes are crucial for an important portion of biodiversity, especially in Europe. We evaluated the effects of land-use changes (1954–2012) on a threatened species, the ortolan bunting, in an agricultural area crucial for its conservation in Italy. We built a distribution model for ortolan bunting in current landscapes and then re-projected it to past scenarios (1954 and 1999–2000). We evaluated the most important land-use changes occurred and estimated their effects on habitat suitability. Bunting occurrence was mostly affected by the extent of grassland (positively; used as foraging/breeding ground), shrubland (quadratic effect; perches/shelter), forest and urbanized land (negatively), and by solar radiation (positively) and slope (quadratic), consistent with other studies carried out especially in southern Europe. The potential distribution of the species was much larger in the past: the estimated decline in suitable habitat is 44–72 % (since 1999–2000/1954), coherent with historical data suggesting strong decline and contraction. Changes in suitability (1954–2012) were mostly associated with changes in the cover of forest, vineyards and abandoned areas (negatively), and shrubland (positively). Land-use/land-cover changes are the main drivers of species occurrence and of habitat decline. The heterogeneous landscape of hilly/low-mountain sites in this area, characterized by a mix of habitats offering complementary resources to ortolan buntings and other species of conservation concern, is currently threatened by abandonment and intensification, but its maintenance may be promoted by a correct definition of Rural Development Programme measures.  相似文献   
169.
Environmental Science and Pollution Research - Microplastic pollution is one of the greatest environmental concerns for contemporary times and the future. In the last years, the number of...  相似文献   
170.
Dispersal is a key determinant of the spatial distribution and abundance of populations, but human-made fragmentation can create barriers that hinder dispersal and reduce population viability. This study presents a modeling framework based on dispersal kernels (modified Laplace distributions) that describe stream fish dispersal in the presence of obstacles to passage. We used mark-recapture trials to quantify summer dispersal of brook trout (Salvelinus fontinalis) in four streams crossed by a highway. The analysis identified population heterogeneity in dispersal behavior, as revealed by the presence of a dominant sedentary component (48-72% of all individuals) characterized by short mean dispersal distance (<10 m), and a secondary mobile component characterized by longer mean dispersal distance (56-1086 m). We did not detect evidence of barrier effects on dispersal through highway crossings. Simulation of various plausible scenarios indicated that detectability of barrier effects was strongly dependent on features of sampling design, such as spatial configuration of the sampling area, barrier extent, and sample size. The proposed modeling framework extends conventional dispersal kernels by incorporating structural barriers. A major strength of the approach is that ecological process (dispersal model) and sampling design (observation model) are incorporated simultaneously into the analysis. This feature can facilitate the use of prior knowledge to improve sampling efficiency of mark-recapture trials in movement studies. Model-based estimation of barrier permeability and its associated uncertainty provides a rigorous approach for quantifying the effect of barriers on stream fish dispersal and assessing population dynamics of stream fish in fragmented landscapes.  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