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201.
Variation in physical factors, such as slope, orientation, and wind exposure, shapes thermal conditions. Variation in substrate size is common in many habitats, but its thermal consequences for organisms are not well characterized. Larger substrates should remain more thermally stable and act as thermal refuges for associated organisms during short, thermally stressful periods such as midday temperature peaks or tidal exposure. In observations and a transplant and thermal integration experiment, we found that larger rock substrates stayed cooler and facilitated greater survival of the barnacle Semibalanus balanoides in the high intertidal relative to small substrates during the hot summer months in southern New England, USA. However, in thermally benign northern New England, rock substrate size had no effect on barnacle distributions, indicating that the thermal effects of substrate size are mediated by regional climate.  相似文献   
202.

Health status depends on multiple genetic and non-genetic factors. Nonheritable factors (such as lifestyle and environmental factors) have stronger impact on immune responses than genetic factors. Firefighters work is associated with exposure to air pollution and heat stress, as well as: extreme physical effort, mental stress, or a changed circadian rhythm, among others. All these factors can contribute to both, short-term and long-term impairment of the physical and mental health of firefighters. Increased levels of some inflammatory markers, such as pro-inflammatory cytokines or C-reactive protein (CRP) have been observed in firefighters, which can lead to local, acute inflammation that promotes a systemic inflammatory response. It is worth emphasizing that inflammation is one of the main hallmarks of cancer and also plays a key role in the development of cardiovascular and respiratory diseases. This article presents possible causes of the development of an inflammatory reaction in firefighters, with particular emphasis on airway inflammation caused by smoke exposure.

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Environmental impact assessment (EIA) has been required for certain proposed road developmentsin the UK since EC Directive (85/337) was implemented in 1988. The extent to which the requirements of the EIA Directive are met with respect to ecological issues has been explored in earlier reviews of road statements (Treweek et al., 1993) and of UK environmental impact statements (EISs) in general (Thompson et al., 1997). This paper describes the results of a further review of 40 EISs produced between 1993 and 1997 and also examines recent changes in the political context for EIA of proposed road developments,including developments in UK transport policy and the UK biodiversity process. The results of the review suggest that the ecological assessment of proposed road developments has improved in some respects, but also highlights the persistence of many shortcomings identified in earlier reviews. The reasons for ongoing failure to address these issues are explored. Key findings include a marked improvement in the extent of reference to consultation with statutory consultees and an increase in the proportion of EISs reporting the results of new ecological surveys. However, while potential ecological impacts were discussed in all the EISs reviewed, many still failed to predict the full range of potential ecological impacts.  相似文献   
205.
Managers and regulators have recognized that the fishing public often ignores fish consumption advisories, and the reasons for non-compliance are explored in this paper. Risk assessors acknowledge that there is a social amplification (intensification) of risk where the public perceive a risk as much more severe than do the 'experts' or scientists, and this social amplification is a function of the interaction of hazards with social, psychological and cultural processes. I propose that non-compliance of consumption advisories occurs because of the deamplification of risk in hazards that are familiar and enjoyed, such as fishing and fish consumption. Although the public are generally aware of consumption advisories, they continue to believe the fish are safe to eat, and a high percentage eat the fish they catch. Unlike the amplification of risk, the deamplification of risk from fishing in the face of consumption advisories is partly legitimized by the actions of some governmental agencies, as well as by society at large. It is suggested that a variety of economic benefits and social institutions lead to a discounting of consumption advisories, and the delayed nature of adverse health effects allows for additional disregard. Further, it is suggested that co-management of the risk from contaminated fish would increase public involvement, and therefore compliance.  相似文献   
206.
Management of ecosystems has been improved both by our understanding of how ecosystems function, as well as by what people consider to be suitable future land uses. This is particularly true with contaminated lands where decisions must be made about clean-up and future land use. In this paper I synthesize several surveys of public recreational rates and preferences for future land use of the Savannah River Site (SRS), a Department of Energy (DoE) facility located in South Carolina. Four groups of people were interviewed: on-site hunters; sportsmen; local residents attending an event near Aiken, South Carolina; and the general public attending a festival in Columbia, South Carolina. The general public that engaged in recreational activities averaged 20 days/ year or more for hunting and fishing, while sportsmen averaged over 50 days/year. All four groups rated maintaining SRS as a National Environmental Research Park (NERP) and using it for recreation as the highest preferred land uses. The general public rated hiking and camping higher than hunting and fishing, while sportsmen rated hunting higher than hiking and camping. All groups rated using SRS for homes as the lowest, or second lowest, preferred land use. There was disagreement on the ratings for industrial development, with people living closer to the site rating it higher than the general South Carolina population. These data can be used by local planners and managers in decision making regarding clean-up levels and future land use. The relative unanimity of views for cleaning up DoE sites, continued use of the site as a NERP and increased recreational use suggests that different groups of people share similar preferences for future use of SRS, and provides a useful paradigm for considering future land use decisions at other DoE sites nationwide. The relatively low ranking for housing and factories suggests that clean-up levels could be geared to future land use, such as recreation, which are less stringent than residential levels.  相似文献   
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Knowing underlying practices for current greenhouse gas (GHG) emissions is a necessary precursor for developing best management practices aimed at reducing N2O emissions. The effect of no-till management on nitrous oxide (N2O), a potent greenhouse gas, remains largely unclear, especially in perennial agroecosystems. The objective of this study was to compare direct N2O emissions associated with management events in a cover-cropped Mediterranean vineyard under conventional tillage (CT) versus no-till (NT) practices. This study took place in a wine grape vineyard over one full growing season, with a focus on the seven to ten days following vineyard floor management and precipitation events. Cumulative N2O emissions in the NT system were greater under both the vine and the tractor row compared to CT, with 0.15 ± 0.026 kg N2O-N ha−1 growing season−1 emitted from the CT vine compared to 0.22 ± 0.032 kg N2O-N ha−1 growing season−1 emitted from the NT vine and 0.13 ± 0.048 kg N2O-N ha−1growing season−1 emitted from the CT row compared to 0.19 ± 0.019 kg N2O-N ha−1 growing season−1 from the NT row. Yet these variations were not significant, indicating no differences in seasonal N2O emissions following conversion from CT to NT compared to long-term CT management. Individual management events such as fertilization and cover cropping, however, had a major impact on seasonal emissions, indicating that management events play a critical role in N2O emission patterns.  相似文献   
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While ecologists have used food‐web models to understand how ecosystems function, the potential role of integrated food‐web and population‐based models in environmental monitoring and decision making has been ignored. Sound ecological principles should be integrated with state‐of‐the‐art monitoring and management practices. This article presents the ways in which population‐based models can answer basic ecological questions necessary for decision making about remediation and restoration, and for monitoring to ensure long‐term stewardship. Discussed are the uses of food‐web and population‐based models for understanding the movement of chemicals through different trophic levels. Three examples, including global warming, tributyltin, and monomethylmercury scenarios, are presented to illustrate how such models are useful. The responses of the component parts varies, depending on parameters such as birth, death, and respiration, as well as feeding rates, predator‐prey rates, and uptake and elimination rates. There are several different models available for decision making, with different levels of complexity, based on the specific hypothesis or question being asked and the amount of current information available. Therefore, it is recommended to use deterministic‐based, population‐based food‐web models for ecological risk assessment. © 2001 John Wiley & Sons, Inc.  相似文献   
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