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排序方式: 共有373条查询结果,搜索用时 15 毫秒
191.
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
192.
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
193.
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
194.
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
195.
196.
197.
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
198.
Sherlock RR Sommer SG Khan RZ Wood CW Guertal EA Freney JR Dawson CO Cameron KC 《Journal of environmental quality》2002,31(5):1491-1501
Much animal manure is being applied to small land areas close to animal confinements, resulting in environmental degradation. This paper reports a study on the emissions of ammonia (NH3), methane (CH4), and nitrous oxide (N2O) from a pasture during a 90-d period after pig slurry application (60 m3 ha-1) to the soil surface. The pig slurry contained 6.1 kg total N m-3, 4.2 kg of total ammoniacal nitrogen (TAN = NH3 + NH4) m-3, and 22.1 kg C m-3, and had a pH of 8.14. Ammonia was lost at a fast rate immediately after slurry application (4.7 kg N ha-1 h-1), when the pH and TAN concentration of the surface soil were high, but the loss rate declined quickly thereafter. Total NH3 losses from the treated pasture were 57 kg N ha-1 (22.5% of the TAN applied). Methane emission was highest (39.6 g C ha-1 h-1) immediately after application, as dissolved CH4 was released from the slurry. Emissions then continued at a low rate for approximately 7 d, presumably due to metabolism of volatile fatty acids in the anaerobic slurry-treated soil. The net CH4 emission was 1052 g C ha-1 (0.08% of the carbon applied). Nitrous oxide emission was low for the first 14 d after slurry application, then showed emission peaks of 7.5 g N ha-1 h-1 on Day 25 and 15.8 g N ha-1 h-1 on Day 67, and decline depending on rainfall and nitrate (NO3) concentrations. Emission finally reached background levels after approximately 90 d. Nitrous oxide emission was 7.6 kg N ha-1 (2.1% of the N applied). It is apparent that of the two major greenhouse gases measured in this study, N2O is by far the more important tropospheric pollutant. 相似文献
199.
William E. Hammitt Bjørn P. Kaltenborn Odd Inge Vistad Lars Emmelin Jon Teigland 《Environmental management》1992,16(2):149-156
Many European countries, including Norway, have a right of common access tradition toward wildland areas for recreational
activity. The “right of any one to move freely over all wildlands except farm fields and gardens” can serve as a paradoxical
barrier to managing wildland areas and users for outdoor recreation. This article discusses the apparent paradox between free
access and management of wildland recreation, the underlying principles of both concepts, and proposes an integrative basis
for how the two concepts can serve the same major goal—freedom of access and use of wildland recreation areas without disturbance
to other users or the resource base. A Norwegian field study is presented with campfire data and management strategies to
illustrate the integrative nature of common access and wilderness management principles for the managing of wildland recreation
opportunities. 相似文献
200.
Analyzing ecotones to predict biotic productivity 总被引:1,自引:0,他引:1
Jon Ghiselin 《Environmental management》1977,1(3):235-238
A technique for predicting the potential biotic productivities of areas is presented. The simple method uses maps or other techniques of remote imagery in comparing adjacent terrestrial and/or littoral areas for investigations when ground reconnaissance is not feasible. Theedge index, the statistical basis for comparison, is calculated as the ratio of the length of a particular ecotone (for example, timberline or shoreline) that would be affected by a proposed development to the affected land area. In similar habitats an unbiased comparison results at the ordinal level of measurement. The method predicts that a higher edge index will correspond to a higher productivity. But because it is not established whether or not the relationship is somehow scalar, the method is not recommended for comparing greatly dissimilar or far distant areas.It has long been observed that ecotones (edges) where two biotic communities meet often produce more game than pure stands of either community. The reasons for this edge effect are reviewed. The demonstrably higher productivity of ecotones is partially explained in terms of the mechanisms that also account for diversity of species.An attempt is made to reconcile theoretical treatments of species diversity with the pragmatic methods for reaching conclusions, which are employed by specialists in resource management. 相似文献