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   617篇
  免费   4篇
  国内免费   7篇
安全科学   31篇
废物处理   41篇
环保管理   77篇
综合类   89篇
基础理论   132篇
环境理论   3篇
污染及防治   184篇
评价与监测   40篇
社会与环境   26篇
灾害及防治   5篇
  2023年   8篇
  2022年   10篇
  2021年   20篇
  2020年   16篇
  2019年   14篇
  2018年   16篇
  2017年   26篇
  2016年   29篇
  2015年   23篇
  2014年   39篇
  2013年   45篇
  2012年   44篇
  2011年   49篇
  2010年   33篇
  2009年   40篇
  2008年   43篇
  2007年   37篇
  2006年   30篇
  2005年   17篇
  2004年   24篇
  2003年   8篇
  2002年   15篇
  2001年   4篇
  2000年   6篇
  1999年   2篇
  1998年   9篇
  1997年   4篇
  1996年   3篇
  1995年   1篇
  1994年   6篇
  1993年   3篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1985年   1篇
排序方式: 共有628条查询结果,搜索用时 15 毫秒
581.
Andrea Gatto 《Ambio》2022,51(9):1921
Commons governance theory is central to identifying and managing conflicts arising from natural and cultural resources traps. Scholars – using game theory and economic analysis of law – have proposed alternative models, consisting of a set of mitigated scenarios, multiple players, and new equilibria in commons governance. Likewise, novel legal innovations of the commons have also been designed. Reinterpreting the commons in light of political economy, ecology, and pluralistic approaches, a critical review of existing scholarship, economic analysis of law, and case study investigations are performed. Examining an array of views – including governance of water in Ecuador, Bolivia, and Italy – a research and policy agenda is put forward to offer original interpretations and novel holistic perspectives. Germane environmental policy implications deriving from SDGs, resilient governance, and polycentric perspectives are thus extrapolated. Finally, pluralistic frameworks drafted by mitigation and adaptation are measured by improved sustainable development performance in commons, resource, and water governance.  相似文献   
582.
Polycyclic aromatic hydrocarbons (PAHs) are organic pollutants derived from pyrolysis and pyrosynthesis processes. Industrial activity, motor vehicle emission, and domestic combustion are the main sources of PAHs in the urban atmosphere. In this work, samples collected during the day and night in the urban area of Sarajevo are analyzed separately for gaseous and particle-bound PAHs; the possible origin of PAHs at the receptor site was suggested using different methods applied to the solid phase and to the total PAHs (gaseous + particulate phase). Finally, the risk level in Sarajevo associated to the carcinogenic character of the studied PAHs has been assessed. The result of this study suggests that (a) the total PAH concentrations were higher than those reported in other European cities; (b) the PAH daytime concentrations are higher than nocturnal concentrations: the sum of the PAH day/night ratios is 1.52 (gas) and 1.45 (particle phase); (c) stationary combustion and traffic were suggested to be the main sources of PAHs; (d) the average particle-bound benzo(a)pyrene (BaP) concentration (5.4 ng/m3) is higher than EU target annual value (1 ng/m3); and (e) PAH cancer risk exceeds the carcinogenic benchmark level recommended by the EPA mainly due to BaP during both the day and night periods.  相似文献   
583.
We examined the isotopic signatures (δ13C, δ15N) of adult body feathers from southern giant petrels Macronectes giganteus collected at two breeding colonies in Antarctica (Potter Peninsula and Cape Geddes) and one in southern Patagonia (Observatorio Island), as well as in whole blood collected from adults of both sexes at each Antarctic colonies and from chicks at Potter Peninsula. As body feather moult is a continuous process in giant petrels, feathers provide an integrated annual signal of an adult’s diets and foraging habitats. In contrast, the stable isotope values of adult and chick blood are reflective of their diets during the breeding season. We found that sex-specific dietary segregation in adults breeding in Antarctica was notable during the breeding season (blood samples) but absent when examined across the entire year (feather samples). In addition, blood stable isotope values differed between chicks and adults, indicating that adults provision their offspring with a relatively higher amount of penguin and seal prey that what they consume themselves. This finding confirms previous work that suggests that chicks are preferentially fed with prey of presumably higher nutritional value such as carrion. Finally, based on isotopic differences between major oceanographic zones in the Southern Ocean, our data indicate population-specific differences in foraging distribution, with Antarctic populations move seasonally between Antarctic and subantarctic zones, while Patagonian populations likely forage in subtropical waters and in continental shelf habitats year-round.  相似文献   
584.
Exposure measurements of concentrations that are non-detectable or near the detection limit (DL) are common in environmental research. Proper statistical treatment of non-detects is critical to avoid bias and unnecessary loss of information. In the present work, we present an overview of possible statistical strategies for handling non-detectable values, including deletion, simple substitution, distributional methods, and distribution-based imputation. Simple substitution methods (e.g., substituting 0, DL/2, DL/ radical2, or DL for the non-detects) are the most commonly applied, even though the EPA Guidance for Data Quality Assessment discouraged their use when the percentage of non-detects is >15%. Distribution-based multiple imputation methods, also known as robust or "fill-in" procedures, may produce dependable results even when 50-70% of the observations are non-detects and can be performed using commonly available statistical software. Any statistical analysis can be conducted on the imputed datasets. Results properly reflect the presence of non-detectable values and produce valid statistical inference. We describe the use of distribution-based multiple imputation in a recent investigation conducted on subjects from the Seveso population exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), in which 55.6% of plasma TCDD measurements were non-detects. We suggest that distribution-based multiple imputation be the preferred method to analyze environmental data when substantial proportions of observations are non-detects.  相似文献   
585.
Simultaneous heavy metal removal mechanism by dead macrophytes   总被引:13,自引:0,他引:13  
The use of dead, dried aquatic plants, for water removal of metals derived from industrial activities as a simple biosorbent material has been increasing in the last years. The mechanism of simultaneous metal removal (Cd2+, Ni2+, Cu2+, Zn2+ and Pb2+) by 3 macrophytes biomass (Spirodela intermedia, Lemna minor and Pistia stratiotes) was investigated. L. minor biomass presented the highest mean removal percentage and P. stratiotes the lowest for all metals tested. Pb2+ and Cd2+ were more efficiently removed by the three of them. The simultaneous metal sorption data were analysed according to Langmuir and Freundlich isotherms. Data fitted the Langmuir model only for Ni and Cd, but Freundlich isotherm for all metals tested, as it was expected. The K(F) values showed that Pb was the metal more efficiently removed from water solution. The adsorption process for the three species studied followed first order kinetics. The mechanism involved in biosorption resulted ion exchange between monovalent metals as counter ions present in the macrophytes biomass and heavy metal ions and protons taken up from water. No significant differences were observed in the metal exchange amounts while using multi-metal or individual metal solutions.  相似文献   
586.
Abstract: A pervious concrete infiltration basin was installed on the campus of Villanova University in August 2002. A study was undertaken to determine what contaminants, if any, were introduced to the soils underlying the site as a result of this best management practice (BMP). The average infiltration rate at the site is approximately 10?4 cm/s. The drainage area (5,208 m2) consists of grassy surfaces (36%), standard concrete/asphalt (30%), and roof surfaces (30%) that directly connect to the infiltration beds via downspouts and storm sewers. Composite samples of infiltrated stormwater were collected from the vadose zone using soil moisture suction devices. Discrete samples were collected from a port within an infiltration bed and a downspout from a roof surface. Samples from 17 storms were analyzed for pH, conductivity, and concentrations of suspended solids, dissolved solids, chloride, copper, and total nitrogen. Copper and chloride were the two constituents of concern at this site. Copper was introduced to the system from the roof, while chloride was introduced from deicing practices. Copper was not found in porewater beneath 0.3 m and the chloride was not significant enough to impact the ground water. This research indicates that with proper siting, an infiltration BMP will not adversely impact the ground water.  相似文献   
587.
Core themes of geomorphology include: open systems and connectivity; feedbacks and complexity; spatial differentiation of dominant physical processes within a landscape; and legacy effects of historical human use of resources. Core themes of ecology include: open systems and connectivity; hierarchical, heterogeneous, dynamic, and context-dependent characteristics of ecological patterns and processes; nonlinearity, thresholds, hysteresis, and resilience within ecosystems; and human effects. Core themes of environmental governance include: architecture of institutions and decision-making; agency, or ability of actors to prescribe behavior of people in relation to the environment; adaptiveness of social groups to environmental change; accountability and legitimacy of systems of governance; allocation of and access to resources; and thresholds and feedback loops within environmental policy. Core themes common to these disciplines include connectivity, feedbacks, tipping points or thresholds, and resiliency. Emphasizing these points of disciplinary overlap can facilitate interdisciplinary understanding of complex systems, as well as more effective management of landscapes and ecosystems by highlighting drivers of change within systems. We use a previously published conceptual framework to examine how these core themes can be integrated into interdisciplinary research for human–landscape systems via the example of a river.  相似文献   
588.
589.
Natural (estradiol, estrone, testosterone, estriol) and synthetic hormones (ethinylestradiol) are constantly excreted into the environment from human and animal sources but little is known of their transport. The purpose of this study was to determine how far along a 100 km river course that hormones could be detected after contamination with sewage effluent or fishpond effluent. Fourteen sites in the Lower Jordan River drainage were sampled (two sites above the sewage effluent contamination, eight sites below the contamination and four tributaries) before and after the dry season of 2002 (Spring and Fall). Samples were tested for testosterone, estrogen (estrone and estradiol combined), estriol, ethinylestradiol, ammonia and fecal coli. It was found that the fecal coli count dropped exponentially (from 250,000 to 60/100 ml3) and the ammonia dropped from 15 to less than 1mg/l over the initial 25 km stretch. Over the same stretch, the hormone values declined by half from their maximum values for testosterone (3.3 ng/l), estriol (8.8 ng/l), ethinylestradiol (6.1 ng/l), and estrogen (4.9 ng/l). From 67 to 100 km mark, testosterone (4.8 ng/l) and estrogen (2.4 ng/l) were still elevated while ethinylestradiol and estriol were >or=1.5 ng/l. The high level of testosterone and estrogen between 67 and 100 km marks was probably due to major discharge from fishponds between 23 and 27 km marks. Levels of ethinylestradiol above 1 ng/l, a level which can affect fish, was seen in 70% (12/16) of the samples tested. The data suggest that hormones in readily measured quantities can be transported considerable distances from the source of pollution.  相似文献   
590.
This contribution discusses a site selection process for establishing a local park. It was supported by a value-focused approach and spatial multi-criteria evaluation techniques. A first set of spatial criteria was used to design a number of potential sites. Next, a new set of spatial and non-spatial criteria was employed, including the social functions and the financial costs, together with the degree of suitability for the park to evaluate the potential sites and to recommend the most acceptable one. The whole process was facilitated by a new software tool that supports spatial multiple criteria evaluation, or SMCE. The application of this tool, combined with a continual feedback by the public administration, has provided an effective methodology to solve complex decisional problem in land-use and urban planning.  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