全文获取类型
收费全文 | 765篇 |
免费 | 16篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 53篇 |
废物处理 | 22篇 |
环保管理 | 116篇 |
综合类 | 231篇 |
基础理论 | 152篇 |
环境理论 | 3篇 |
污染及防治 | 127篇 |
评价与监测 | 35篇 |
社会与环境 | 26篇 |
灾害及防治 | 17篇 |
出版年
2023年 | 12篇 |
2021年 | 11篇 |
2020年 | 21篇 |
2019年 | 8篇 |
2018年 | 23篇 |
2017年 | 13篇 |
2016年 | 26篇 |
2015年 | 28篇 |
2014年 | 15篇 |
2013年 | 38篇 |
2012年 | 47篇 |
2011年 | 52篇 |
2010年 | 29篇 |
2009年 | 39篇 |
2008年 | 38篇 |
2007年 | 36篇 |
2006年 | 37篇 |
2005年 | 18篇 |
2004年 | 13篇 |
2003年 | 18篇 |
2002年 | 22篇 |
2001年 | 12篇 |
2000年 | 9篇 |
1999年 | 14篇 |
1998年 | 9篇 |
1997年 | 11篇 |
1995年 | 7篇 |
1994年 | 12篇 |
1992年 | 6篇 |
1991年 | 10篇 |
1989年 | 5篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1974年 | 5篇 |
1971年 | 4篇 |
1967年 | 6篇 |
1965年 | 4篇 |
1964年 | 4篇 |
1961年 | 7篇 |
1960年 | 4篇 |
1957年 | 4篇 |
1956年 | 4篇 |
1948年 | 4篇 |
1940年 | 3篇 |
1937年 | 3篇 |
1928年 | 3篇 |
1920年 | 5篇 |
1916年 | 3篇 |
1913年 | 3篇 |
排序方式: 共有782条查询结果,搜索用时 968 毫秒
231.
The relationship between migration and deforestation in the developing world continues to receive significant attention. However beyond direct population increase, the precise mechanisms that operate within the intersection of migrant/host land rights remain largely unexamined. Where migrants are provided with land and rights by the State and/or local communities, how such rights are perceived by the migrants is of primary importance in their interaction with land resources, and in aggregate it impacts the development opportunities and environmental repercussions of migration. The authors analyze the operative aspects of land rights reception (as opposed to provision) by migrant populations, and the relationship between this reception and deforestation. The article examines a case in Zambia to analyze how tenurial constructs, emerging from the way rights are perceived by migrants, lead to the continued clearing of areas much larger than needed for cultivation, even when the arrangement appears counter‐productive in terms of land rights provision and labour allocation. While valuable policy efforts have focused on providing resource rights to migrants, how such rights are received and the relationship of this reception to resource management needs greater policy attention. 相似文献
232.
Toward Sustainable Management of National Parks in Japan: Securing Local Community and Stakeholder Participation 总被引:4,自引:0,他引:4
Hiwasaki L 《Environmental management》2005,35(6):753-764
Japan’s national park system constitutes a potentially viable mechanism for securing local community participation and building stakeholder consensus for sustainable park management, although the potential of this system is yet to be fully maximized. This article gives an overview of the system of protecting natural resources in Japan, focusing on the national park system. Parks are managed by zoning and regulation, which is unique in that land is not “set aside” for nature conservation, but designated as national park wherever the need to preserve “scenic beauty” has been recognized, regardless of land ownership or land use. Although resource conservation under this system has been problematic, it has advantages, especially in terms of community participation. This article demonstrates that in order to reach the system’s potential, the park authority must act as coordinator of stakeholders and facilitator of bottom-up approaches to decision-making. In order to do this, steps that must be taken include the following: identifying the various stakeholders in park management and defining the “local community”; clarifying the roles and responsibilities of each stakeholder; and supporting consensus-building among stakeholders regarding the objectives and long-term vision of each park. By taking these steps, it would be possible to build a park management system that overrides government boundaries and involves local communities. This will enable the park authority to address the challenges facing Japan’s complex system of conserving natural resources, and move towards sustainable management of natural resources in Japan. 相似文献
233.
Manfred Lenzen Sven Lundie Grant Bransgrove Lisa Charet Fabian Sack 《Journal of Environmental Planning and Management》2003,46(1):113-141
Faced with the task of communicating their combined social, environmental and economic impact, water service providers are seeking to report overall performance in an aggregated way. Such a methodology must be scientifically robust, easily communicated and allow benchmarking of performance while reflecting a transition towards sustainability. In this paper the ecological footprint (EF) is calculated for Sydney Water Corporation (SWC), using input-output analysis and land disturbance in an innovative approach that overcomes problems identified in the original EF concept. This pilot study has allowed SWC to gain some valuable insights into its impacts: SWC's annual EF is about 73 100 ha in terms of land disturbance. Of this, 54 000 ha are projected to become disturbed as a consequence of climate change, with the remainder of 19 100 ha being disturbed on SWC's premises (2400 ha) and on those of upstream suppliers (16 700 ha). Total on-site impacts equal 9300 ha, while indirect land disturb ance contributes 63 600 ha. The EF appears promising as an educational and communi cation tool and may have potential as a decision support tool. However, further research is needed to incorporate downstream impacts into the EF, which would have significant benefits to SWC in terms of assessing and communicating the organization's overall progress towards sustainability. 相似文献
234.
Recently, our attention has focused on the low level detection of many antibiotics, pharmaceuticals, and other organic chemicals in water resources. The limited studies available suggest that urban or rural streams receiving wastewater effluent are more susceptible to contamination. The purpose of this study was to evaluate the occurrence of antibiotics, pharmaceuticals, and other organic chemicals at 18 sites on seven selected streams in Arkansas, USA, during March, April, and August 2004. Water samples were collected upstream and downstream from the influence of effluent discharges in northwestern Arkansas and at one site on a relatively undeveloped stream in north-central Arkansas. At least one antibiotic, pharmaceutical, or other organic chemical was detected at all sites, except at Spavinaw Creek near Mayesville, Arkansas. The greatest number of detections was observed at Mud Creek downstream from an effluent discharge, including 31 pharmaceuticals and other organic chemicals. The detection of these chemicals occurred in higher frequency at sites downstream from effluent discharges compared to those sites upstream from effluent discharges; total chemical concentration was also greater downstream. Wastewater effluent discharge increased the concentrations of detergent metabolites, fire retardants, fragrances and flavors, and steroids in these streams. Antibiotics and associated degradation products were only found at two streams downstream from effluent discharges. Overall, 42 of the 108 chemicals targeted in this study were found in water samples from at least one site, and the most frequently detected organic chemicals included caffeine, phenol, para-cresol, and acetyl hexamethyl tetrahydro naphthalene (AHTN). 相似文献
235.
What Makes Them Pay? Values of Volunteer Tourists Working for Sea Turtle Conservation 总被引:1,自引:0,他引:1
As charismatic mega-fauna, sea turtles attract many volunteers to conservation programs. This article examines the ways in
which volunteers value sea turtles, in the specific context of volunteers working with the Caribbean Conservation Corporation,
at Tortuguero, Costa Rica. The complexity of volunteer values is explored using a qualitative approach. In-depth interviews
with 31 volunteers were conducted in July of 1999 and 2000. Interviews probed, among other things, interest in sea turtles
and their conservation, motives for participating, and the most gratifying parts of their volunteer experience. Results show
that volunteers hold multiple and complex values for sea turtles, but particular values dominate. Results have implications
for understanding human–environment relations and the emerging study of volunteer tourism. There are also management implications
for volunteer programs hoping to attract participants. 相似文献
236.
Non-structural streambank stabilization, or bioengineering, is a common stream restoration practice used to slow streambank
erosion, but its ecological effects have rarely been assessed. We surveyed bank habitat and sampled bank macroinvertebrates
at four bioengineered sites, an unrestored site, and a comparatively less-impacted reference site in the urban Peachtree-Nancy
Creek catchment in Atlanta, GA, USA. The amount of organic bank habitat (wood and roots) was much higher at the reference
site and three of the bioengineered sites than at the unrestored site or the other bioengineered site, where a very different
bioengineering technique was used (“joint planting”). At all sites, we saw a high abundance of pollution-tolerant taxa, especially
chironomids and oligochaetes, and a low richness and diversity of the bank macroinvertebrate community. Total biomass, insect
biomass, and non-chironomid insect biomass were highest at the reference site and two of the bioengineered sites (p < 0.05). Higher biomass and abundance were found on organic habitats (wood and roots) versus inorganic habitats (mud, sand,
and rock) across all sites. Percent organic bank habitat at each site proved to be strongly positively correlated with many
factors, including taxon richness, total biomass, and shredder biomass. These results suggest that bioengineered bank stabilization
can have positive effects on bank habitat and macroinvertebrate communities in urban streams, but it cannot completely mitigate
the impacts of urbanization. 相似文献
237.
Importance of Riparian Forests in Urban Catchments Contingent on Sediment and Hydrologic Regimes 总被引:1,自引:0,他引:1
Roy AH Freeman MC Freeman BJ Wenger SJ Ensign WE Meyer JL 《Environmental management》2006,37(4):523-539
Forested riparian corridors are thought to minimize impacts of landscape disturbance on stream ecosystems; yet, the effectiveness
of streamside forests in mitigating disturbance in urbanizing catchments is unknown. We expected that riparian forests would
provide minimal benefits for fish assemblages in streams that are highly impaired by sediment or hydrologic alteration. We
tested this hypothesis in 30 small streams along a gradient of urban disturbance (1–65% urban land cover). Species expected
to be sensitive to disturbance (i.e., fluvial specialists and “sensitive” species that respond negatively to urbanization)
were best predicted by models including percent forest cover in the riparian corridor and a principal components axis describing
sediment disturbance. Only sites with coarse bed sediment and low bed mobility (vs. sites with high amounts of fine sediment)
had increased richness and abundances of sensitive species with higher percent riparian forests, supporting our hypothesis
that response to riparian forests is contingent on the sediment regime. Abundances of Etheostoma scotti, the federally threatened Cherokee darter, were best predicted by models with single variables representing stormflow (r2 = 0.34) and sediment (r2 = 0.23) conditions. Lentic-tolerant species richness and abundance responded only to a variable representing prolonged duration
of low-flow conditions. For these species, hydrologic alteration overwhelmed any influence of riparian forests on stream biota.
These results suggest that, at a minimum, catchment management strategies must simultaneously address hydrologic, sediment,
and riparian disturbance in order to protect all aspects of fish assemblage integrity. 相似文献
238.
A straightened stream stretch with poor habitat heterogeneity was divided into a “control” section with a low amount of submerged woody debris and an experimentally “wood-enriched” downstream section to study the effect of enhanced habitat diversity on the benthic invertebrate community. The downstream section was enriched by fixing 25 wood packages constructed from 9–10 branches on the stream bottom. Succession processes occurring in the two stream sections were compared by chironomid exuviae drift from July to November 2000 and from April to August 2001. During the first sampling period, more drifting chironomid exuviae (medians of control vs. wood-enriched: 446 vs. 331, no significant difference) and total number of taxa (44 vs. 36, Wilcoxon signed-rank test P = 0.019) were recorded for the control section. Although species compositions of both stream sections were highly similar (Sørensen index: 0.83) the diversity in the wood-enriched section was distinctly lower compared to the control section (Shannon–Weaver index: 1.19 vs. 1.50). During the second sampling period, exuviae numbers remained higher in the control section (median: 326 vs. 166), but total numbers of taxa were nearly equal (51 vs. 49), as well as species diversity (Shannon–Weaver index: 1.67 vs. 1.64). The lower chironomid diversity observed during the first sampling period coincided with a gradual but significant change of the streambed morphology in the wood-enriched section. There, the initially more U-shaped profile (V/U = 0.81 ± 0.37) had turned into a pronounced V shape (V/U = 1.14 ± 0.21), whereas the control section retained its unaltered U shape (V/U = 0.62–0.75). This small-scale study on experimental of woody debris in sandy lowland streams showed that the negative impact of increased hydraulic disturbance of the existing streambed more than outweighed any positive impact resulting from the increase in woody debris. 相似文献
239.
Disaster risk, climate change and international development: scope for, and challenges to, integration 总被引:7,自引:0,他引:7
Reducing losses to weather-related disasters, meeting the Millennium Development Goals and wider human development objectives, and implementing a successful response to climate change are aims that can only be accomplished if they are undertaken in an integrated manner. Currently, policy responses to address each of these independently may be redundant or, at worst, conflicting. We believe that this conflict can be attributed primarily to a lack of interaction and institutional overlap among the three communities of practice. Differences in language, method and political relevance may also contribute to the intellectual divide. Thus, this paper seeks to review the theoretical and policy linkages among disaster risk reduction, climate change and development. It finds that not only does action within one realm affect capacity for action in the others, but also that there is much that can be learnt and shared between realms in order to ensure a move towards a path of integrated and more sustainable development. 相似文献
240.
On the basis of the literature of open systems and team diversity, we present a new dynamic team diversity theory that explains the effect of change in team diversity on team functioning and performance in the context of dynamic team composition. Building upon the conceptualization of teams as open systems, we describe the enlargement and decline of team variety, separation, and disparity through member addition, subtraction, and substitution. Then, focusing on diversity enlargement, we theorize the contemporaneous and lasting effects of team diversity change on team performance change and on team processes and states leading to them. Dynamic team diversity theory expands the focus of team diversity research from teams' being more diverse than others to teams' becoming more diverse than before. It aims to advance team diversity research to be better aligned with the organizational reality of dynamic team composition. We also discuss methodological considerations in subsequent empirical testing of the theory and highlight how the theory and future research may help to guide organizational practice in recomposing work teams. 相似文献