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61.
Celia A Harvey Arnulfo Medina Dalia Merlo Sánchez Sergio Vílchez Blas Hernández Joel C Saenz Jean Michel Maes Fernando Casanoves Fergus L Sinclair 《Ecological applications》2006,16(5):1986-1999
As tropical regions are converted to agriculture, conservation of biodiversity will depend not only on the maintenance of protected forest areas, but also on the scope for conservation within the agricultural matrix in which they are embedded. Tree cover typically retained in agricultural landscapes in the neotropics may provide resources and habitats for animals, but little is known about the extent to which it contributes to conservation of animal species. Here, we explore the animal diversity associated with different forms of tree cover for birds, bats, butterflies, and dung beetles in a pastoral landscape in Nicaragua. We measured species richness and abundance of these four animal taxa in riparian and secondary forest, forest fallows, live fences, and pastures with high and low tree cover. We recorded over 20,000 individuals of 189 species including 14 endangered bird species. Mean abundance and species richness of birds and bats, but not dung beetles or butterflies, were significantly different among forms of tree cover. Species richness of bats and birds was positively correlated with tree species richness. While the greatest numbers of bird species were associated with riparian and secondary forest, forest fallows, and pastures with >15% tree cover, the greatest numbers of bat species were found in live fences and riparian forest. Species assemblages of all animal taxa were different among tree cover types, so that maintaining a diversity of forms of tree cover led to conservation of more animal species in the landscape as a whole. Overall, the findings indicate that retaining tree cover within agricultural landscapes can help conserve animal diversity, but that conservation efforts need to target forms of tree cover that conserve the taxa that are of interest locally. Preventing the degradation of remaining forest fragments is a priority, but encouraging farmers to maintain tree cover in pastures and along boundaries may also make an important contribution to animal conservation. 相似文献
62.
Dianne L. Watson Euan S. Harvey Gary A. Kendrick Kim Nardi Marti J. Anderson 《Marine Biology》2007,152(5):1197-1206
Closure of areas to fishing is expected to result in an increase in the abundance of targeted species; however, changes to
populations of species not targeted by fishermen will depend upon their role in the ecosystem and their relationship with
targeted species. The effects of protection on targeted and non-targeted reef fish species at the Houtman Abrolhos Islands,
Western Australia were studied using baited remote underwater stereo–video cameras. Video images were collected from shallow
(8–12 m) and deep (22–26 m) reef sites inside a Marine Protected Area (MPA) at each of three island groups and from three
replicate fished locations at each of these groups that span a temperate-tropical transition area. The MPAs were established
in 1994 and vary in size from 13.72 km2 at the Pelsaert group in the south to 22.29 km2 at the Easter group to 27.44 km2 at the Wallabi group in the north. The relative abundances of 137 fish species from 42 families were recorded. Large differences
in fish assemblage structure existed between MPA and fished locations, and also between shallow and deep regions. Targeted
fish species Plectropomus leopardus, Lethrinus miniatus, Lethrinus nebulosus, Pagrus auratus and Glaucosoma hebraicum were more abundant inside MPAs than in areas open to fishing. Their abundance inside MPAs was between 1.13 and 8 times greater
than their abundance at fished locations. For non-targeted fish species many were more abundant in areas open to fishing,
e.g. Coris auricularis, Thalassoma lutescens, Thalassoma lunare, Dascyllus trimaculatus, however others were conversely more abundant inside MPAs, e.g. Gymnothorax spp, Kyphosus sydneyanus, Scarus microhinos, Chromis westaustralis, Chaetodon spp. This study demonstrates that the removal of abundant targeted species from an ecosystem by fishing can indirectly impact
non-fished species and alter the trophic structure of fish assemblages.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
63.
64.
Exposure to perchlorate is widespread in the United States and many studies have attempted to character the perchlorate exposure by estimating the average daily intakes of perchlorate. These approaches provided population-based estimates, but did not provide individual-level exposure estimates. Until recently, exposure activity database such as CSFII, TDS and NHANES become available and provide opportunities to evaluate the individual-level exposure to chemical using exposure surveillance dataset. In this study, we use perchlorate as an example to investigate the usefulness of urinary biomarker data for predicting exposures at the individual level. Specifically, two analyses were conducted: (1) using data from a controlled human study to examine the ability of a physiologically based pharmacokinetic (PBPK) model to predict perchlorate concentrations in single-spot and cumulative urine samples; and (2) using biomarker data from a population-based study and a PBPK model to demonstrate the challenges in linking urinary biomarker concentrations to intake doses for individuals. Results showed that the modeling approach was able to characterize the distribution of biomarker concentrations at the population level, but predicting the exposure-biomarker relationship for individuals was much more difficult. The type of information needed to reduce the uncertainty in estimating intake doses, for individuals, based on biomarker measurements is discussed. 相似文献
65.
R. B. Harvey D. H. Stedman W. Chameides 《Journal of the Air & Waste Management Association (1995)》2013,63(7):663-666
Improvements made on the direct NO2 photolysis actinometer developed by J. O. Jackson have produced more precise data. A plot of measured values of the photolysis rate J1 vs Eppley uv photometer readings produces a curved rather than the straight line correlation previously reported. This curvature arises from the Eppley and NO2 absorption spectrum overlap, backround surface albedoes, the Ep-pley's cosine response and inherent errors in the chemical equation used. New J1 measurement vs Eppley data is shown, and a procedure for calculating instantaneous J-i values from an Eppley output is suggested. 相似文献
66.
Psychological entitlement refers to the phenomenon in which individuals consistently believe that they deserve preferential rewards and treatment, often with little consideration of actual qualities or performance levels. This study examines the influence of psychological entitlement on workplace outcomes, using attribution theory to explain its effects. Results suggested that entitlement perceptions are positively associated with self‐serving attribution styles and that diminished need for cognition mediates this relationship. Self‐serving attribution styles, in turn, were associated with reduced job satisfaction and increased levels of conflict with supervisors. A direct positive relationship between psychological entitlement and turnover intent was also observed. Overall, results suggest that an attributional perspective is useful in explaining and understanding the influence of entitlement perceptions on workplace outcomes. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
67.
68.
Microbial diversity and spatial distribution of the diversity within tissue of the marine sponge Tethya californiana was analyzed based on 16S rRNA gene sequences. One candidate division and nine bacterial phyla were detected, including members
of all five subdivisions of Proteobacteria. Moreover, chloroplast-derived Stramenopiles- and Rhodophyta-affiliated 16S rRNA gene sequences were found and Stramenopiles represented the most abundant clones (30%) in the clone library. On the phylum-level, the microbial fingerprint of T. californiana showed a similar pattern as its Mediterranean relative T. aurantium. An interesting difference was that Cyanobacteria that were abundantly present in T. aurantium were not found in T. californiana, but that the latter sponges harbored phototrophic Stramenopiles instead. Surprisingly, the phototrophic microorganisms were evenly distributed over the inner and outer parts of the sponge
tissue, which implies that they also reside in regions without direct light exposure. The other phyla were also present in
both the outer cortex and the mesohyl of the sponges. These results were confirmed by analysis on the operational taxonomic
unit level. This leads to the conclusion that from a qualitative point of view, spatial distribution of microorganisms in
T. californiana tissue is quite homogeneous. Thirty-two percent of the operational taxonomic units shared less than 95% similarity with any
other known sequence. This indicates that marine sponges are a rich source of previously undetected microbial life. 相似文献
69.
Australian approaches to coastal vulnerability assessment 总被引:2,自引:1,他引:1
The Australian coastline is one of the longest and most diverse of any in the world, and Australian researchers have developed
preliminary models of the behaviour of major coastal systems such as beaches and reefs. The Australian population is particularly
focused along the coastline, especially in metropolitan centres; however, the population of regional centres along the coast
is increasing steadily in response to a phenomenon termed seachange. Coastal systems are increasingly threatened by potential
impacts as a result of climate change, as indicated by the successive assessments by the Intergovernmental Panel on Climate
Change (IPCC). Although Australia played a central role in applying a common methodology (CM), developed from IPCC guidelines
in the 1990s, and in devising alternative approaches, which were initially trialled at nine sites on the Australian coast,
there has not been a nationally co-ordinated approach to assessing the coastal vulnerability of Australia, and such an approach
is only emerging now. Instead, there have been a series of different approaches adopted to look at the different parts of
the Australian coast, including wetland mapping in northern Australia; geomorphic unit mapping in South Australia; storm surge
vulnerability modelling in Queensland; probabilistic approaches to beach erosion in New South Wales; indicative mapping of
potential coastal retreat in Tasmania. Additionally, there have been methods proposed by insurers and coastal engineers to
meet their requirements. Since 2005, the Australian government has once again seen the need for a national coastal vulnerability
assessment, and a series of studies are planned or under way to achieve the aims of a National Climate Change Adaptation Framework. 相似文献
70.