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排序方式: 共有97条查询结果,搜索用时 15 毫秒
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Laura E. Coristine Sheila Colla Nathan Bennett Anja M. Carlsson Christina Davy Kimberley T.A. Davies Brett Favaro D.T. Tyler Flockhart Kevin Fraser Diane Orihel Sarah P. Otto Wendy Palen Jean L. Polfus Oscar Venter Adam T. Ford 《Conservation biology》2019,33(5):1219-1223
Current conservation templates prioritize biogeographic regions with high intensity ecosystem values, such as exceptional species richness or threat. Intensity-based targets are an important consideration in global efforts, but they do not capture all available opportunities to conserve ecosystem values, including those that accrue in low intensity over large areas. We assess six globally-significant ecosystem values—intact wilderness, freshwater availability, productive marine environments, breeding habitat for migratory wildlife, soil carbon storage, and latitudinal potential for range shift in the face of climate change—to highlight opportunities for high-impact broadly-distributed contributions to global conservation. Nations can serve as a cohesive block of policy that can profoundly influence conservation outcomes. Contributions to global ecosystem values that exceed what is predicted by a nation's area alone, can give rise to countries with the capacity to act as ‘conservation superpowers’, such as Canada and Russia. For these conservation superpowers, a relatively small number of national policies can have environmental repercussions for the rest of the world. 相似文献
84.
Climate determines upper, but not lower, altitudinal range limits of Pacific Northwest conifers 总被引:1,自引:0,他引:1
Does climate determine species' ranges? Rapid rates of anthropogenic warming make this classic ecological question especially relevant. We ask whether climate controls range limits by quantifying relationships between climatic variables (precipitation, temperature) and tree growth across the altitudinal ranges of six Pacific Northwestern conifers on Mt. Rainier, Washington, USA. Results for three species (Abies amabilis, Callitropsis nootkatensis, Tsuga mertensiana) whose upper limits occur at treeline (> 1600 m) imply climatic controls on upper range limits, with low growth in cold and high snowpack years. Annual growth was synchronized among individuals at upper limits for these high-elevation species, further suggesting that stand-level effects such as climate constrain growth more strongly than local processes. By contrast, at lower limits climatic effects on growth were weak for these high-elevation species. Growth-climate relationships for three low-elevation species (Pseudotsuga menziesii, Thuja plicata, Tsuga heterophylla) were not consistent with expectations of climatic controls on upper limits, which are located within closed-canopy forest (< 1200 m). Annual growth of these species was poorly synchronized among individuals. Our results suggest that climate controls altitudinal range limits at treeline, while local drivers (perhaps biotic interactions) influence growth in closed-canopy forests. Climate-change-induced range shifts in closed-canopy forests will therefore be difficult to predict accurately. 相似文献
85.
The people of the Democratic Republic of Congo for decades have been living in a situation of chronic crisis. Violence, population displacement and the destruction of infrastructure and health services have devastated the health of the population. In 2001, Médicins Sans Frontières conducted a survey in five areas of western and central DRC to assess mortality, access to health-care, vaccination coverage and exposure to violence. High mortality rates were found in front-line zones, mainly due to malnutrition and infectious diseases. In Basankusu approximately 10 per cent of the total population and 25 per cent of the under-five population had perished in the year before the survey. Humanitarian needs remain acute across the country, particularly near the front line. Infectious-disease control and treatment are a priority, as is increasing access to health-care. Humanitarian assistance must be increased considerably, especially in rural areas and zones that have been affected directly by conflict. 相似文献
86.
Ford CI Walter M Northcott GL Di HJ Cameron KC Trower T 《Journal of environmental quality》2007,36(6):1749-1759
This study was conducted to improve the ability of indigenous New Zealand white-rot fungi to remove pentachlorophenol (PCP) from contaminated field soil. The effects of different bioaugmentation conditions on PCP removal and extracellular enzyme expression were measured in the laboratory. The conditions were fungal growth substrate and co-substrate composition, culture age, and Tween 80 addition to the contaminated soil. The fungi used were Trametes versicolor isolate HR131 and Trametes sp. isolate HR577. Maximum PCP removal was 70% after 7 wk from a 1043 mg kg(-1) PCP-contaminated soil inoculated with an 11-d-old fungal culture of T. versicolor isolate HR131. There was minimal production of undesirable pentachloroanisole by the fungi. Tween 80 addition had no affect on PCP removal. Poplar sawdust was more suitable as a fungal growth substrate and a co-substrate amendment for PCP removal and extracellular enzyme expression than the locally available pine and fir sawdust. Pentachlorophenol removal was not necessarily correlated with extracellular enzyme expression. The research results demonstrate that PCP biodegradation was affected by inoculum culture age, by the presence of a co-substrate amendment, and by growth substrate composition after white-rot fungal bioaugmentation into PCP-contaminated field soils. 相似文献
87.
IntroductionCarbondioxide(CO2 )isaprincipalgreenhousegasandthereforetheirair waterexchangesareimportantproblemsinterrestrialecosystemsforclimatechangestudy(Frankignoulle ,1 998;Chimel,2 0 0 1 ) .ThedirectionofCO2 gasexchange(evasionorinvasion)isdependentonthedirectionoftheCO2concentrationgradientbetweentheairandthesurfacewater;themagnitudeoftheexchangedependsadditionallyonthegasexchangecoefficient,k.Alloflakesinland ,withitssmallareabutlargeatmosphericCO2 fluxrange ,playanimportantroleinev… 相似文献
88.
Reducing the environmental impact of offshore operations is one of the most pressing challenges facing the oil and gas industry in Europe today. A study was conducted to review the issues by literature search, and consultation with stakeholders and experts. It was clear from the literature search that considerable research had been dedicated to: protecting the marine environment; achieving compliance with legislative controls; assessing the technical and economic feasibility of platform disposal options; and ecological surveying. By comparison, considerably less research had been carried out in other important areas such as: assessing the impacts wastes returned to shore for disposal; identifying sustainable strategies for operations; and assessing and mitigating against adverse impacts from atmospheric emissions. It is clear that the environmental regulatory regime offshore will become tougher and have an increasing influence on offshore oil and gas field environmental planning and management. Future regulatory developments include: a streamlining of the offshore oil and gas environmental regulatory regime; the introduction of the Habitats Directive into the licensing system; and the Offshore Combustion Installations (Prevention and Control of Pollution) Regulations 1999. In addition, post Kyoto regulatory developments and societal concern over atmospheric pollution, will increasingly focus efforts on reducing the emission of global warming gases. These changes, coupled with the uncertainty over how resilient the environment is to perturbation, present a need to clearly manage environmental information. 相似文献
89.
By changing riparian plants from Eucalypts to pasture and exotic deciduous trees, modern development has altered the type of carbon assimilated by Australian rivers. To investigate influences of plant litter substrates on biochemical oxygen demand, plant materials entering the Murray River were analyzed for their composition and mineralization potential. Plant materials were distinguished compositionally by two principal components, structural carbon and macronutrients, as: (i) Eucalyptus leaves, (ii) Eucalyptus bark and Casuarina cunninghamiana seed cone, (iii) grasses, (iv) macrophytes, (v) aquatic herbs, (vi) non-eucalypt leaf (Salix, Casuarina, Acacia). Ratios of C/P (1879-14524) and C/N (65-267) were relatively high in Eucalyptus bark, while mean N/P (7-60) ratios were similar among plant materials. Terrestrial weathering increased C/P and C/N ratios, while N/P ratios remained similar, due to greater loss of N and P relative to C. Aerobic decay experiments showed that nutrient supplementation accelerated decay of all organic substrates, except for grasses that decayed efficiently without supplementation. Aquatic herbs also had substantial carbon availability, macrophytes and non-eucalypt leaves had intermediate carbon availability, while eucalypt leaf and bark had intermediate to low carbon availabilities. Because biochemical oxygen demand varies with organic substrates sampled from the Murray River, and also with soluble nutrient availability, it is plausible that that modern changes to riverine plant communities and land use have influenced the biogeochemistry of this river toward faster, and more complete, processing of allochthonous carbon. 相似文献
90.
David T. Ford Darryl W. Davis 《Journal of the American Water Resources Association》1985,21(1):135-144
ABSTRACT: The U.S. Army Corps of Engineers has broad, nationwide water resources planning and management responsibilities. In response to the needs of Corps professionals, the Hydrologic Engineering Center (HEC) has developed and supports a family of computer programs designed to aid them in their work. These programs include catchment, channel, alluvial, and statistical process models, system operation models, plan evaluation models, and data management programs. These models individually and collectively have been used throughout the Corps in a wide range of water resources planning studies. 相似文献