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281.
L. Ignacio Vilchis Joseph R. Evenson Scott F. Pearson Karen L. Barry Peter Davidson Martin G. Raphael Joseph K. Gaydos 《Conservation biology》2015,29(1):154-163
Identifying drivers of ecosystem change in large marine ecosystems is central for their effective management and conservation. This is a sizable challenge, particularly in ecosystems transcending international borders, where monitoring and conservation of long‐range migratory species and their habitats are logistically and financially problematic. Here, using tools borrowed from epidemiology, we elucidated common drivers underlying species declines within a marine ecosystem, much in the way epidemiological analyses evaluate risk factors for negative health outcomes to better inform decisions. Thus, we identified ecological traits and dietary specializations associated with species declines in a community of marine predators that could be reflective of ecosystem change. To do so, we integrated count data from winter surveys collected in long‐term marine bird monitoring programs conducted throughout the Salish Sea—a transboundary large marine ecosystem in North America's Pacific Northwest. We found that decadal declines in winter counts were most prevalent among pursuit divers such as alcids (Alcidae) and grebes (Podicipedidae) that have specialized diets based on forage fish, and that wide‐ranging species without local breeding colonies were more prone to these declines. Although a combination of factors is most likely driving declines of diving forage fish specialists, we propose that changes in the availability of low‐trophic prey may be forcing wintering range shifts of diving birds in the Salish Sea. Such a synthesis of long‐term trends in a marine predator community not only provides unique insights into the types of species that are at risk of extirpation and why, but may also inform proactive conservation measures to counteract threats—information that is paramount for species‐specific and ecosystem‐wide conservation. Evaluación de las Correlaciones Ecológicas de las Declinaciones de Aves Marinas para Informar a la Conservación Marina 相似文献
282.
R. Eisler M. M. Barry R. L. Lapan Jr. G. Telek E. W. Davey A. E. Soper 《Marine Biology》1978,45(4):311-317
Benthic fauna were collected from 17 stations in mid-Narragansett Bay, Rhode Island, during September 1973 from the vicinity of the recently-closed Quonset Point electroplating facility. Despite repeated sampling, most of the 14 species of molluscs taken, including the widgeon clam Pitar morrhuana, were absent from stations in the immediate vicinity of plant outfalls. In general, P. morrhuana captured near outfall sites exhibited high moisture content and elevated body burdens of silver, cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead, and zinc compared to clams of similar size from more distant stations. Observed changes in metal concentrations and moisture content of P. morrhuana were probably attributable to plant operations during the preceding 30 years. 相似文献
283.
284.
Ross G. Dwyer Hamish A. Campbell Richard D. Pillans Matthew E. Watts Barry J. Lyon Siddeswara M. Guru Minh N. Dinh Hugh P. Possingham Craig E. Franklin 《Conservation biology》2019,33(6):1426-1437
The optimal design of reserve networks and fisheries closures depends on species occurrence information and knowledge of how anthropogenic impacts interact with the species concerned. However, challenges in surveying mobile and cryptic species over adequate spatial and temporal scales can mask the importance of particular habitats, leading to uncertainty about which areas to protect to optimize conservation efforts. We investigated how telemetry-derived locations can help guide the scale and timing of fisheries closures with the aim of reducing threatened species bycatch. Forty juvenile speartooth sharks (Glyphis glyphis) were monitored over 22 months with implanted acoustic transmitters and an array of hydrophone receivers. Using the decision-support tool Marxan, we formulated a permanent fisheries closure that prioritized areas used more frequently by tagged sharks and considered areas perceived as having high value to fisheries. To explore how the size of the permanent closure compared with an alternative set of time-area closures (i.e., where different areas were closed to fishing at different times of year), we used a cluster analysis to group months that had similar arrangements of selected planning units (informed by shark movements during that month) into 2 time-area closures. Sharks were consistent in their timing and direction of migratory movements, but the number of tagged sharks made a big difference in the placement of the permanent closure; 30 individuals were needed to capture behavioral heterogeneity. The dry-season (May–January) and wet-season (February–April) time-area closures opened 20% and 25% more planning units to fishing, respectively, compared with the permanent closure with boundaries fixed in space and time. Our results show that telemetry has the potential to inform and improve spatial management of mobile species and that the temporal component of tracking data can be incorporated into prioritizations to reduce possible impacts of spatial closures on established fisheries. 相似文献
285.
286.
J Barry Smith 《Journal of Environmental Economics and Management》1980,7(3):209-219
This paper partially extends the replenishable resource management literature to the case of uncertainty. Stochastic resource dynamics are defined, studied and estimated. The results of this study suggest that the misallocation of resources into the northern lobster fishery has been greater than was previously believed. While aggregate stochastic influences are small in the lobster fishery, the dynamics of whales appear to be significantly affected by stochastic influences. 相似文献
287.
Burger J Gochfeld M Kosson DS Powers CW Jewett S Friedlander B Chenelot H Volz CD Jeitner C 《Journal of environmental radioactivity》2006,91(1-2):27-40
Levels of radionuclides in seven species of marine brown algae and Ulva were determined to establish a baseline for the Northern Pacific Ocean/Bering Sea (Aleutian Islands). There were differences in levels among algal species and locations (Amchitka Island vs Kiska Island). No values were above the minimum detectable activity (MDA) level for (137)Cs, (129)I, (60)Co, (152)Eu, (90)Sr, and (99)Tc. There were interspecific differences in some radionuclides: Ulva lactuca (=Ulva fenestrata) had the highest levels of (241)Am, Alaria fistulosa had the highest levels of (239,240)Pu, and Fucus distichus (=Fucus gardneri) had the highest levels of (234)U, (235)U, and (238)U. However, levels of all radionuclides were generally low and near the MDA for all isotopes. Although Amchitka Island had higher levels of (239,240)Pu than Kiska, the differences were very small and not significant biologically. The data indicate that algae can be useful bioindicators of actinides because they accumulate them at very low environmental levels, allowing them to provide early warning of any potential seepage of radionuclides into the marine environment. Further, the data indicate that some species (the intertidal Fucus) are better accumulators than others, and these should be used as bioindicators in future monitoring schemes. 相似文献
288.
A longitudinal assessment of the aquatic macroinvertebrate community in the channelized lower Missouri River 总被引:1,自引:0,他引:1
Poulton BC Wildhaber ML Charbonneau CS Fairchild JF Mueller BG Schmitt CJ 《Environmental monitoring and assessment》2003,85(1):23-53
We conducted an aquatic macroinvertebrate assessment in the channelized reach of the lower Missouri River, and used statistical analysis of individual metrics and multimetric scores to identify community response patterns and evaluate relative biological condition. We examined longitudinal site differences that are potentially associated with water qualityrelated factors originating from the Kansas City metropolitan area, using data from coarse rock substrate in flowing water habitats (outside river bends), and depositional mud substratein slack water habitats (dike fields). Three sites above rivermile (RM) 369 in Kansas City (Nebraska City, RM = 560; St. Joseph, RM = 530; Parkville, RM = 377) and three below (Lexington, RM = 319; Glasgow, RM = 228; Hermann, RM = 94) were sampled with rock basket artificial substrates, a qualitative kicknet method, and the Petite Ponar. We also compared the performance of the methods used. A total of 132 aquatic macroinvertebrate taxa were collected from the lower Missouri River; one third of these taxa belonged to the sensitiveEPOT insect orders (Ephemeroptera, Plecoptera, Odonata, and Trichoptera). Rock baskets had the highest mean efficiency (34.1%) of the methods, and the largest number of taxa was collected by Ponar (n = 69) and kicknet (n = 69) methods. Seven of the 15 metrics calculated from rock basket data, and five ofthe nine metrics calculated from Ponar data showed highly significant differences (ANOVA, P < 0.001) at one or more sitesbelow Kansas City. We observed a substantial reduction in net-spinning Trichoptera in rock habitats below Kansas City (Lexington), an increase in relative dominance of Oligochaeta in depositional habitats at the next site downstream (Glasgow), and lower relative condition scores in rock habitat at Lexingtonand depositional habitat at Glasgow. Collectively, these data indicate that some urban-related impacts on the aquatic macroinvertebrate community are occurring. Our results suggest that the methods and assessment framework we used in this studycould be successfully applied on a larger scale with concurrentwater and sediment chemistry to validate metrics, establish impairment levels, and develop a specific macroinvertebrate community index for the lower Missouri River. We recommend accomplishing this with longitudinal multi-habitat sampling at a larger number of sites related to all potential sources of impairment, including major tributaries, urban areas, and point sources. 相似文献
289.
Stephen Bocking David Gibbs Susie Ohlenschlager Darlene E. Clover Timothy Boston Peder Hjorth Barry Solomon Julian Hine Iris Turner 《Local Environment》1999,4(3):385-397
Toward Sustainable Communities: resources for citizens and their governments. Mark Roseland with Maureen Cureton & Heather Wornell, 1998, Gabriola Island, New Society Publishers, ISBN 0 86571 374 X, $18.95
First Mover Advantage by Eco-efficiency: local incentives for environment and employment.. C. Erdmunger & S. Schreckenberger, 1998, Freiburg, ICLEI, DM30
Agendas for Sustainability: environment and development into the twenty-first century. Mary Macdonald, 1998, London, Routledge, ISBN 0 415 15491X, £55.00 (hbk)
Women, Population and Global Crisis: a political-economic analysis. Asoka Bandarage, 1997, London, Zed Books, ISBN 1 85649 428 4, £15.95 (pbk)
Spirit of the Environment: religion, value, and environmental concern. David Cooper & Joy Palmer (Eds), 1998, London, Routledge, ISBN 0 4151 4202 4, £12.99 (pbk)
Environmental Transition in Nordic and Baltic Countries. Hans Aage (Ed.), 1998, (New Horizons in Environmental Economics). Cheltenham, UK and Northampton, MA, USA, Edward Elgar, ISBN 1 85898 629 X
Sustainability Indicators: measuring the immeasurable. Simon Bell & Stephen Morse, 1999, London, Earthscan Publications, 175 pp. ISBN 1 85383 498 X, LE14.95 (pbk)
The Economics of Road Transport Regulation. Erik Verhoef, Cheltenham, Edward Elgar 1996, 265 pp. ISBN 1 85898 364 9, £55.00
The Water Crisis. Julie Stauffer, London, Earthscan, 1998, ISBN 185383 436X, £12.95 (pbk) 相似文献
First Mover Advantage by Eco-efficiency: local incentives for environment and employment.. C. Erdmunger & S. Schreckenberger, 1998, Freiburg, ICLEI, DM30
Agendas for Sustainability: environment and development into the twenty-first century. Mary Macdonald, 1998, London, Routledge, ISBN 0 415 15491X, £55.00 (hbk)
Women, Population and Global Crisis: a political-economic analysis. Asoka Bandarage, 1997, London, Zed Books, ISBN 1 85649 428 4, £15.95 (pbk)
Spirit of the Environment: religion, value, and environmental concern. David Cooper & Joy Palmer (Eds), 1998, London, Routledge, ISBN 0 4151 4202 4, £12.99 (pbk)
Environmental Transition in Nordic and Baltic Countries. Hans Aage (Ed.), 1998, (New Horizons in Environmental Economics). Cheltenham, UK and Northampton, MA, USA, Edward Elgar, ISBN 1 85898 629 X
Sustainability Indicators: measuring the immeasurable. Simon Bell & Stephen Morse, 1999, London, Earthscan Publications, 175 pp. ISBN 1 85383 498 X, LE14.95 (pbk)
The Economics of Road Transport Regulation. Erik Verhoef, Cheltenham, Edward Elgar 1996, 265 pp. ISBN 1 85898 364 9, £55.00
The Water Crisis. Julie Stauffer, London, Earthscan, 1998, ISBN 185383 436X, £12.95 (pbk) 相似文献
290.
Spectral properties of salt crusts formed on saline soils 总被引:3,自引:0,他引:3
Rapid identification and large-scale mapping of salt-affected lands will help improve salinity management in watersheds and ecosystems. This study was conducted to examine spectral reflectance of soils treated with saline solutions containing NaCl, NaHCO3, Na2SO4, and CaSO4.2H2O. Spectral reflectance was measured upon salt crusts formed on two soils (Torrifluvents) subirrigated with saline solutions of 500, 1000, and 1500 mmolc L-1 with a spectroradiometer in the visible and near-infrared region (400-2500 nm). Spectral analyses revealed that samples of gypsum crusts have diagnostic absorption features near 1023, 1225, 1457, 1757, 1800, and 2336 nm, whereas halite crusts have diagnostic absorption features near 1442, 1851, 1958, and 2226 nm. Several broad absorption features were seen in the spectra of the crusts of sodium bicarbonate at 1243, 1498, 1790, 1988, and 2356 nm. The spectrum of soils treated with sodium sulfate exhibited absorption features at 1243, 1472, 1677, 1774, 1851, 1968, and 2245 nm. Crystal size or salt concentrations did not affect the positions of the absorption bands of the salt crusts. However, reflectance increased as particle sizes decreased or with increasing presence of salt crusts. Spectroscopy can be used under certain conditions to identify the presence of primary diagnostic spectral features of gypsum, nahcolite, thenardite, and halite crusts. 相似文献