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排序方式: 共有375条查询结果,搜索用时 46 毫秒
191.
Matthew C McBain Jon S Warland Raymond A McBride Claudia Wagner-Riddle 《Waste management & research》2005,23(5):409-419
Micrometeorological measurements of methane (CH4) and nitrous oxide (N2O) emissions were made at the decommissioned Park Road Landfill in Grimsby, Ontario, Canada between June and August 2002. The influence of precipitation, air temperature, wind speed and barometric pressure on the temporal variability of landfill biogas emissions was assessed. Gas flux measurements were obtained using a micrometeorological mass balance measurement technique [integrated horizontal flux (IHF)] in conjunction with two tunable diode laser trace gas analyser (TDLTGA) systems. This method allows for continuous, non-intrusive measurements of gas flux at high temporal resolution. Mean fluxes of N2O were negligible over the duration of the study (-0.23 to 0.02 microg m(-2) s(-1)). In contrast, mean emissions of CH4 were much greater (80.4 to 450.8 microg m(-2) s(-1)) and varied both spatially and temporally. Spatial variations in CH4 fluxes were observed between grass kill areas (biogas 'hot spots') and the densely grass-covered areas of the landfill. Temporal variations in CH4 fluxes were also observed, due at least in part to barometric pressure, wind speed and precipitation effects. 相似文献
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Sarmiento Jon Marx P. Mendez Queenie Lynly T. Estaña Leo Manuel B. Giray Evette S. Nañola Cleto L. Alviola Pedro A. 《Environment, Development and Sustainability》2021,23(11):16786-16802
Environment, Development and Sustainability - The Philippine fisheries sector continues to play a critical role in the livelihood of coastal households; however, the country’s fisheries... 相似文献
195.
This paper provides a first analysis of a “policy bloc” of fossil fuel importers which implements an optimal climate policy, faces a (non-policy) fringe of other fuel importers, and an exporter bloc, and purchases offset from the fringe. We compare a carbon tax and a cap-and-trade scheme for the policy bloc, in either case accompanied by an efficient offset mechanism for reducing emissions in the fringe. The policy bloc is shown to prefer a tax over a cap, since only a tax reduces the fuel export price and by more when the policy bloc is larger. Offsets are also more favorable to the policy bloc under a tax than under a cap. The optimal offset price under a carbon tax is below the tax rate, while under a cap and free quota trading the offset price must equal the quota price. The domestic carbon and offset prices are both higher under a tax than under a cap when the policy bloc is small. When the policy bloc is larger, the offset price can be higher under a cap. Fringe countries gain by mitigation in the policy bloc, more under a carbon tax since the fuel import price is lower. 相似文献
196.
Our disappearing past: a GIS analysis of the vulnerability of coastal archaeological resources in California’s Santa Barbara Channel region 总被引:1,自引:0,他引:1
Leslie A. Reeder Torben C. Rick Jon M. Erlandson 《Journal of Coastal Conservation》2012,16(2):187-197
Coastal archaeological resources around the world often coincide with dense contemporary human populations and a rapidly changing
physical environment. Projected sea level rise and urban expansion during the 21st century threaten to destroy much of our global coastal archaeological heritage. In this study, we adapt an environmental
vulnerability analysis to quantify the threats of modern development and sea level rise on archaeological sites in California’s
Santa Barbara Channel region. Using spatial and statistical techniques, we create a Cultural Resource Vulnerability Index
that combines environmental factors, current and projected urban footprints, and archaeological site positioning. We illustrate
the importance of this method for targeting threatened archaeological sites for mitigation and salvage research. In the process,
we highlight the significance of coastal archaeological sites for helping better understand contemporary environmental and
cultural issues, underscoring the need to preserve or salvage these sites for their significant research value. 相似文献
197.
Noninvasive genetic sampling has been embraced by wildlife managers and ecologists, especially those charged with monitoring rare and elusive species over large areas. Challenges arise when desired population measures are not directly attainable from genetic data and when monitoring targets trans-border populations. Norwegian management authorities count individual brown bears (Ursus arctos) using noninvasive genetic sampling but express management goals in the annual number of bear reproductions (females that produce cubs), a measure that is not directly available from genetic data. We combine noninvasive genetic sampling data with information obtained from a long-term intensive monitoring study in neighboring Sweden to estimate the number of annual reproductions by females detected within Norway. Most female brown bears in Norway occur near the border with neighboring countries (Sweden, Finland, and Russia) and their potential reproduction can therefore only partially be credited to Norway. Our model includes a simulation-based method that corrects census data to account for this. We estimated that 4.3 and 5.7 reproductions can be credited to females detected with noninvasive genetic sampling in Norway in 2008 and 2009, respectively. These numbers fall substantially short of the national target (15 annual reproductions). Ignoring the potential for home ranges to extend beyond Norway's borders leads to an increase in the estimate of the number of reproductions by -30%. Our study shows that combining noninvasive genetic sampling with information obtained from traditional intensive/invasive monitoring can help answer contemporary management questions in the currency desired by managers and policy makers. Furthermore, combining methodologies and thereby accounting for space use increases the accuracy of the information on which decisions are based. It is important that the information derived from multiple approaches is applicable to the same focal population and that predictions are cross-validated. When monitoring and management are constrained to administrative units, census data should be adjusted by discounting portions of individual space utilization that extend beyond the focal jurisdiction. Our simulation-based approach for making such an adjustment may be useful in other situations where management authorities target portions of trans-border populations. 相似文献
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The role of off-farm employment in tropical forest conservation: labor, migration, and smallholder attitudes toward land in western Uganda 总被引:4,自引:0,他引:4
The potential for off-farm employment (OFE) to contribute significantly to forest conservation in the tropics is a widely held logic among donors, governments, and social scientists. While an aggregate level examination of OFE cases can support this logic, there is disagreement as to the operative aspects of specific linkages and assumptions. This study examines the case of the tea industry in western Uganda, and uses a combination of fieldwork and remote sensing to pursue a more nuanced examination of the role of migration and non-monetary aspects of OFE on forest conservation in both a national park and unprotected forest contexts. Results indicate that the tea industry does serve as an off-farm employer to a limited number of local smallholders but these benefits are offset by the industry's overwhelming dependence on migrant labor which sees OFE as temporary, then seeks to settle locally. There is also evidence that the tea industry is contributing to conservation efforts of Kibale National Park by unintentionally serving as a physical buffer zone, which inhibits both human encroachment on the park and wildlife encroachment on smallholder crops. The latter represents a site-specific phenomenon that holds much potential for future management plans of the area and exemplifies the importance of considering the site-specific circumstances associated with OFE development. 相似文献