全文获取类型
收费全文 | 3760篇 |
免费 | 35篇 |
国内免费 | 12篇 |
专业分类
安全科学 | 79篇 |
废物处理 | 258篇 |
环保管理 | 297篇 |
综合类 | 402篇 |
基础理论 | 768篇 |
环境理论 | 6篇 |
污染及防治 | 1392篇 |
评价与监测 | 350篇 |
社会与环境 | 242篇 |
灾害及防治 | 13篇 |
出版年
2023年 | 44篇 |
2022年 | 102篇 |
2021年 | 150篇 |
2020年 | 63篇 |
2019年 | 68篇 |
2018年 | 148篇 |
2017年 | 144篇 |
2016年 | 209篇 |
2015年 | 109篇 |
2014年 | 228篇 |
2013年 | 356篇 |
2012年 | 261篇 |
2011年 | 270篇 |
2010年 | 210篇 |
2009年 | 135篇 |
2008年 | 215篇 |
2007年 | 249篇 |
2006年 | 170篇 |
2005年 | 139篇 |
2004年 | 104篇 |
2003年 | 82篇 |
2002年 | 85篇 |
2001年 | 46篇 |
2000年 | 37篇 |
1999年 | 24篇 |
1998年 | 12篇 |
1997年 | 9篇 |
1996年 | 9篇 |
1995年 | 15篇 |
1994年 | 10篇 |
1993年 | 7篇 |
1992年 | 6篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1988年 | 4篇 |
1982年 | 3篇 |
1978年 | 2篇 |
1970年 | 2篇 |
1967年 | 4篇 |
1966年 | 4篇 |
1965年 | 3篇 |
1964年 | 5篇 |
1963年 | 2篇 |
1962年 | 4篇 |
1961年 | 2篇 |
1959年 | 4篇 |
1958年 | 15篇 |
1957年 | 5篇 |
1956年 | 2篇 |
1955年 | 2篇 |
排序方式: 共有3807条查询结果,搜索用时 15 毫秒
961.
Ángel Uruburu Eva Ponce-Cueto José Ramón Cobo-Benita Joaquín Ordieres-Meré 《Waste management (New York, N.Y.)》2013,33(3):679-688
Directive 2008/98/EC released by the European Union represents a significant step forward in all relevant aspects of waste management. Under the already established, extended produced responsibility (EPR) principle, new policies have been enunciated to continuously achieve better overall environmental performance of key products throughout their life phases. This paper discusses how the directive is being articulated in Spain by the main integrated management system (IMS) for end-of-life (EOL) tyres since its creation in 2006. Focusing on the IMS technological, economic and legal aspects, the study provides a global perspective and evaluation of how the IMS is facing the current issues to resolve, the new challenges that have appeared and the management vision for the coming years. 相似文献
962.
M.R. Mosquera-Losada N. Muñoz-Ferreiro A. Rigueiro-Rodríguez 《Waste management (New York, N.Y.)》2010,30(3):492-503
Spain is one of the main municipal sewage sludge producers of Europe. This paper aims to agronomically characterise different types of sewage sludge stabilised by different methods (anaerobically digested, composted, and pelletised) and deliver policy recommendations from the results of this characterisation. Anaerobic sewage sludge quality is found to be better in plants with a lower volume of water processing. Composted sludge shows the best quality from a heavy metal point of view, but its low available nitrogen content increases the input of heavy metals when spread, as compared to digested or pelletised sludge. Pelletised sludge has higher heavy metal content than anaerobically digested sludge. Despite the good quality of the sludges, future regulations, especially with regard to Cd levels, will limit the use of this waste in agriculture. 相似文献
963.
964.
The suggestion that utility is logically necessary for behavioural adjustments to be made in response to changes in intrinsic risk is fundamental to risk homeostasis theory (RHT). However, the methodology used to investigate RHT — analysis of road traffic accidents — is ill-suited to the investigation of this assertion. The role of utility and intrinsic risk as possible determinants of behavioural compensation were therefore examined experimentally across 14 specific behaviours using the Aston Driving Simulator. RHT predicts that these two factors act in a multiplicative way to form a statistical interaction. It also predicts that the behavioural pathways through which the effect manifests itself should be reconcilable with the concept of utility. Both predictions received little support in this experiment, suggesting that utility and intrinsic risk operate as independent factors: both factors produced significant main effects across a number of behaviours. This finding, if it can be generalised, implies that, contrary to mathematically-based models of danger compensation and the traditional model of risk homeostasis, utility is not logically necessary for behavioural compensation in response to a change in intrinsic risk. 相似文献
965.
Malins C Doyle A MacCraith BD Kvasnik F Landl M Simon P Kalvoda L Lukas R Pufler K Babusík I 《Journal of environmental monitoring : JEM》1999,1(5):417-422
The realisation of an opto-chemical ammonia sensor suitable for personal monitoring tasks is described, comprising a cyanine dye immobilised in a microporous glass thin film. The fabrication of sensor platforms incorporating embossed grating couplers provides a compact optical design with effective waveguiding characteristics, resulting in reversible ammonia sensitivity in the 5-100 ppm range in under 2 min. Cross-sensitivity of sensor response with water and other potential interferents is considered. 相似文献
966.
Kristen Ounanian Jan P.M. van Tatenhove Paulina Ramírez-Monsalve 《Journal of Environmental Policy & Planning》2020,22(2):211-225
ABSTRACTIn the North Sea, many oil and gas fields will reach the end of their productivity and their associated structures will be decommissioned. OSPAR decision 98/3 prescribes removal of all disused offshore structures as the only acceptable decommissioning option. This policy is the legacy of the 1995 Brent Spar incident, which resulted in the current dominant discourse of ‘Hands off the Oceans,’ ruling out the conversion of oil and gas rigs into artificial reefs (Rigs-to-Reefs (RtR)). The shift from a conservation to a restoration paradigm could open up the RtR debate. In this paper, a discourse analysis is carried out to discern whether and how ideas about RtR and ecosystem restoration are articulated to challenge the dominant ‘Hands off the Oceans’ discourse and thereby bring about change in North Sea decommissioning policy. A discourse analytic framework is applied to elucidate whether an ‘RtR as Restoration’ discourse can be distinguished and how competing claims are presented in the various storylines. Our analysis shows an ‘RtR as Restoration’ discourse, consisting of four different storylines. Given the fragmented nature of this discourse, the ‘RtR as Restoration’ discourse will not overcome the dominant ‘Hands off the Oceans’ discourse. 相似文献
967.
A. Meana-Fernández L. Díaz-Artos J.M. Fernández Oro S. Velarde-Suárez 《International Journal of Green Energy》2020,17(3):181-195
ABSTRACTIn this work, a new airfoil shape optimized for vertical-axis wind turbine applications is proposed. Different airfoil shapes have been analyzed with JavaFoil, a panel method software. Then, the results from the analysis have been used to optimize the performance of the new airfoil shape. Afterward, Computational Fluid Dynamics (CFD) simulations of the proposed airfoil, UO-17-LDA, are run for different angles of attack to provide insight into the flow field and the mechanisms related to this increase in performance. The UO-17-LDA airfoil presents a high lift-to-drag ratio and a delayed stall angle with respect to the original FX-63-137 airfoil, making it suitable for vertical-axis wind turbine applications. This increase in performance has been verified by comparing two VAWT designs with the original and the proposed airfoil using a double-multiple streamtube model. Finally, the practicality of JavaFoil for the comparison of different airfoil geometries has been verified, as it is capable of obtaining results for a wide number of flow conditions in small computational times and with a user-friendly interface. Nevertheless, the results diverge from the actual solution for high angles of attack (beyond stall). Hence, the time and effort required to perform CFD simulations is justified to gain insight into the actual behavior of a particular airfoil, as well as to obtain a richer analysis of the flow field and the mechanisms related to the airfoil performance. 相似文献
968.
Methods for determination of minimum pool levels in reservoirs that consider sport fishery values are being sought by managers.
We developed a technique for assessing the effects of incremental changes in minimum pool levels on potential salmonid abundance
in small (<100 surface hectares at full pool) reservoirs in Wyoming managed for irrigation and municipal water supplies. The
method has two components. One component is used to determine the minimum pool level needed to eliminate the risk of overwinter
loss of salmonids due to low dissolved oxygen concentrations. The other component predicts the potential biomass of salmonids
in reservoirs as a function of water depth and total dissolved solids concentration of the reservoir water. Application of
the method is demonstrated for two reservoirs in Wyoming.
The unit is jointly supported by the University of Wyoming, the Wyoming Game and Fish Department, and the US Fish and Wildlife
Service. 相似文献
969.
The Management of a Large Mediterranean Reservoir: Storage Regimens of the Yesa Reservoir,Upper Aragon River Basin,Central Spanish Pyrenees 总被引:2,自引:0,他引:2
Agriculture in Mediterranean countries is mainly based upon the irrigation of productive areas in the lowlands. For this reason, it is necessary to store large volumes of water in reservoirs located in mountain headwaters. These reservoirs have a relatively simple regimen of storage, increasing the water stored during the wet season (from October until May) and reaching the maximum volume shortly before the beginning of the hot, very dry season, when the water is released. This paper considers the storage regimen (inflow and outflow) of the Yesa Reservoir in the Spanish Pyrenees as an example of management of a large reservoir in a mountain Mediterranean environment, subject to a strong interannual variability. On average, the highest water storage level is achieved by retaining the high flows of the Aragón River in autumn and spring. Nevertheless, the irregularity of rainfalls and the existence of changes in the hydrological regimen lead to changes in the patterns of reservoir filling. Two patterns were identified in the Yesa Reservoir: (1) a quick increase of the stored volume in autumn, a stabilization in winter, and a new increase in spring; and (2) a continuous increase from October until May. These patterns are distributed in time over different periods since the construction of the reservoir in 1959, demonstrating the adjustment of the reservoir management to changes in the hydrological regimen. 相似文献
970.
Ahumada I Escudero P Carrasco MA Castillo G Ascar L Fuentes E 《Journal of environmental monitoring : JEM》2004,6(4):327-334
In Chile, the increasing number of plants for the treatment of wastewater has brought about an increase in the generation of sludge. One way of sludge disposal is its application on land; this, however involves some problems, some of them being heavy metal accumulation and the increase in organic matter and other components from sewage sludge which may change the distribution and mobility of heavy metals. The purpose of the present study was to determine the effect of sewage sludge application on the distribution of Cr, Ni, Cu, Zn and Pb in agricultural soils in Chile. Three different soils, two Mollisols and one Alfisol, were sampled from an agricultural area in Central Chile. The soils were treated with sewage sludge at the rates of 0 and 30 ton ha(-1), and were incubated at 25 degrees C for 45 days. Before and after incubation, the soils were sequentially extracted to obtain labile (exchangeable and sodium acetate-soluble), potentially labile (soluble in moderately reducing conditions, K4P2O7-soluble and soluble in reducing conditions) and inert (soluble in strong acid oxidizing conditions) fractions. A two-level factored design was used to assess the effect of sludge application rate, incubation time and their interaction on the mobility of the elements under study. Among the metals determined in the sludge, zinc has the highest concentration. However, with the exception of Ni, the total content of metals was lower than the recommended limit values in sewage sludge as stated by Chilean regulations. Although 23% of zinc in sludge was in more mobile forms, the residual fraction of all metals was the predominant form in soils and sludge. The content of zinc only was significantly increased in two of the soils by sewage sludge application. On the other hand, with the exception of copper, the metals were redistributed in the first four fractions of amended soils. The effect of sludge application rate, incubation time and their interaction depended on the metal or soil type. In most cases an increase in more mobile forms of metals in soils was observed as the final effect. 相似文献