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841.
Development of a New Approach to Cumulative Effects Assessment: A Northern River Ecosystem Example 总被引:2,自引:0,他引:2
Dubé M Johnson B Dunn G Culp J Cash K Munkittrick K Wong I Hedley K Booty W Lam D Resler O Storey A 《Environmental monitoring and assessment》2006,113(1-3):87-115
If sustainable development of Canadian waters is to be achieved, a realistic and manageable framework is required for assessing cumulative effects. The objective of this paper is to describe an approach for aquatic cumulative effects assessment that was developed under the Northern Rivers Ecosystem Initiative. The approach is based on a review of existing monitoring practices in Canada and the presence of existing thresholds for aquatic ecosystem health assessments. It suggests that a sustainable framework is possible for cumulative effects assessment of Canadian waters that would result in integration of national indicators of aquatic health, integration of national initiatives (e.g., water quality index, environmental effects monitoring), and provide an avenue where long-term monitoring programs could be integrated with baseline and follow-up monitoring conducted under the environmental assessment process. 相似文献
842.
An international workshop held in the spring of 2002 convened a group of technical experts to address monitoring, modeling,
and management of PCBs within the Detroit River-Western Lake Erie basin. Participants shared and discussed a diverse set of
research data bases pertaining to PCB levels within the region, discussed observed changes within different components of
the local ecosystem, and identified several primary issues impacting future PCB management strategies. Results presented at
the workshop indicate dramatic reductions in PCB contamination levels have been observed in much of study area between the
late 1970s and mid-1990s. Estimates of loadings attributable to water and atmospheric sources have generally declined, as
have PCB concentrations in herring gull eggs, smelt and walleye. Nevertheless, additional improvements have not been observed
during recent years and elevated contamination levels remain a concern within local hot spots, particularly in the lower Detroit
River and Trenton Channel. A primary recommendation broadly supported by workshop participants is the need to maintain, support,
and coordinate a comprehensive ecosystem monitoring program for the Detroit River-Western Lake Erie basin, one that incorporates
both near-field and far-field monitoring elements. Such a program is crucial to provide necessary data in support of understanding
ecosystem trends, calculating annual mass loadings to the system, assessing impacts of remediation actions, developing improved
modeling frameworks, and formulating cost-effective management strategies for the future. 相似文献
843.
Fajer-Avila EJ García-Vásquez A Plascencia-González H Ríos-Sicairos J García-De La Parra LM Betancourt-Lozano M 《Environmental monitoring and assessment》2006,122(1-3):221-237
The relationship between parasites and environmental stress were studied in two tropical coastal lagoons of Northwest Mexico: Urias estuary (highly polluted) and Teacapan estuary (slightly polluted). Metazoan parasites were examined in 292 white mullet (Mugil curema) specimens collected bimonthly during a year from both systems. Haliotrema mugilinus, Metamicrocotyla macracantha, Ergasilus sp., Caligus sp., Holobomolochus sp., and Lernaeopodidae were found in gills, while Contracaecum sp. larvae III was found liver, hepatic portal vein and kidneys. Ecological indices were influenced by the slightly higher number of parasitic species in Urias compared to Teacapan, as well as the clear dominance of two species: Ergasilus sp. and Contracaecum sp. in both systems. In fact, Ergasilus sp. showed considerably higher abundance in Urias, possibly indicating that its success was a result of adverse conditions affecting the host, while Contracaecum sp showed higher abundances in Teacapan, suggesting that the environmental conditions occurring in Urias could have produced negative impacts on the nematode's infective potential. 相似文献
844.
An assessment of tree health and trace element accumulation near a coal-fired generating station, Manitoba, Canada 总被引:2,自引:0,他引:2
A forest health assessment was performed in stands dominated by bur oak and trembling aspen to study the potential effects of airborne emissions from a 132 MW coal-fired station. Forty-two stands were sampled within a 16-km radius of the station for both foliar stress symptoms and trace element toxicology. The concentrations of tracer elements (As, Ba, Sr, and V) in the leaf litter were not spatially congruent with airborne emission deposition models (except Ba, which showed elevated levels immediately SE of the station), nor were they at phytotoxic levels. Elemental concentrations were significantly related to soil parameters including organic matter and texture. No patterns were found in forest health along directional or distance gradients from the generating station. Trembling aspen stands demonstrated little decline in general, but three of the 19 bur oak plots, all located on thin sandy soils developed on calcareous till, demonstrated branch dieback. In addition to poor soil conditions, two of these sites also had high water tables, and exhibited tree mortality. The bur oak decline did not appear to be related to emissions from the station, but is suspected to be a result of poor site quality, with urban development as a confounding factor. 相似文献
845.
Will Smith 《Ambio》2022,51(3):485
Zoonotic disease emergence has become a core concern of biodiversity conservation amid the ongoing impacts of the COVID-19 pandemic. Major international conservation groups now comprehensively center larger human–nature imbalances not only as problems of global public health but as a core challenge of the conservation movement, alongside habitat destruction, biodiversity loss and climate change. There is, however, little consideration of how new biosecurity concerns might alter conservation practice with unexpected and potential harmful impacts on human communities, particularly in developing nations with significant human–wildlife interfaces. Reviewing emerging policy positions from key conservation organizations, this article argues that the proposed responses to the COVID-19 pandemic hold the potential to (a) amplify existing people-park conflicts, and (b) generate new tensions by integrating global systems of viral surveillance into biodiversity conservation. I conclude that the close integration of biosecurity concerns into conservation policies requires greater acknowledgment of the unique challenges for human communities.Supplementary InformationThe online version of this article (10.1007/s13280-021-01576-0) contains supplementary material, which is available to authorized users. 相似文献
846.
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848.
A.R. Melwani S.N. Bezalel J.A. Hunt J.L. Grenier G. Ichikawa W. Heim A. Bonnema C. Foe D.G. Slotton J.A. Davis 《Environmental pollution (Barking, Essex : 1987)》2009,157(11):3137-3149
A three-year study was conducted to examine mercury in sport fish from the Sacramento–San Joaquin Delta. More than 4000 fish from 31 species were collected and analyzed for total mercury in individual muscle filets. Largemouth bass and striped bass were the most contaminated, averaging 0.40 μg/g, while redear sunfish, bluegill and rainbow trout exhibited the lowest (<0.15 μg/g) concentrations. Spatial variation in mercury was evaluated with an analysis of covariance model, which accounted for variability due to fish size and regional hydrology. Significant regional differences in mercury were apparent in size-standardized largemouth bass, with concentrations on the Cosumnes and Mokelumne rivers significantly higher than the central and western Delta. Significant prey–predator mercury correlations were also apparent, which may explain a significant proportion of the spatial variation in the watershed. 相似文献
849.
Eric Mellink Mónica E. Riojas-López 《Environmental pollution (Barking, Essex : 1987)》2009,157(7):2184-2188
We determined egg concentrations of organochlorines and thickness of eggshells from brown boobies at eight colonies ranging from the northern Gulf of California to southern Mexico. The only common residue was that of DDE, which was found in almost all eggs. DDE content apparently reflected pre-1990 DDT use in nearby agricultural areas and, at one site, intensive mosquito control for high-end tourism development. There were no inter-colony differences in eggshell thickness, and variation in this variable likely reflected individual bird characteristics and/or individual feeding source. This variable was not a good proxy to DDE exposure of brown boobies, under current DDE levels in the brown booby trophic chain. In the northern Gulf of California, eggshell thickness has recovered to pre-DDT conditions. Our data indicate that the Gulf of California and southwestern coast of Mexico have a healthy near-shore marine environment, as far as organochlorines are concerned. 相似文献
850.
Climate and land-use changes affecting river sediment and brown trout in alpine countries—a review 总被引:1,自引:1,他引:0
Karin Scheurer Christine Alewell Dominik Bänninger Patricia Burkhardt-Holm 《Environmental science and pollution research international》2009,16(2):232-242