全文获取类型
收费全文 | 258篇 |
免费 | 2篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 12篇 |
废物处理 | 12篇 |
环保管理 | 42篇 |
综合类 | 39篇 |
基础理论 | 50篇 |
污染及防治 | 71篇 |
评价与监测 | 14篇 |
社会与环境 | 22篇 |
灾害及防治 | 2篇 |
出版年
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 4篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 7篇 |
2016年 | 7篇 |
2015年 | 5篇 |
2014年 | 10篇 |
2013年 | 37篇 |
2012年 | 11篇 |
2011年 | 12篇 |
2010年 | 12篇 |
2009年 | 7篇 |
2008年 | 12篇 |
2007年 | 16篇 |
2006年 | 14篇 |
2005年 | 12篇 |
2004年 | 9篇 |
2003年 | 8篇 |
2002年 | 14篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1970年 | 1篇 |
1933年 | 1篇 |
1931年 | 1篇 |
排序方式: 共有264条查询结果,搜索用时 250 毫秒
191.
Robert J. Zomer Antonio Trabucco Louis V. Verchot Bart Muys 《Mitigation and Adaptation Strategies for Global Change》2008,13(3):219-239
Within the United Nations Framework Convention on Climate Change (UNFCCC) Kyoto Protocol, countries have significant latitude
to define a forest. The most important parameter affecting area designated as forest is the minimum crown cover which can
be set between 10 and 30%. The choice will have implications for the amount of land available in a country for afforestation
and reforestation activities within the Clean Development Mechanism (CDM-AR). In this paper, we present an analysis of the
regional differences in land availability for CDM-AR projects. We then examine how the choice of a high or low threshold value
for crown cover will affect the area available for CDM activities and how the limitations imposed by this element of the definition
compares to other factors that are likely to limit CDM activities. Results represent a global analysis that included all countries
not included in Annex I of the Kyoto Protocol, and examined the effect on land availability of a range of crown cover thresholds
ranging from 10–30%. Of the 140 Non-Annex One countries, 107 countries were found to have a potential for CDM-AR projects.
Asia had the largest amount of combined area suitable for CDM-AR at the 10% crown cover threshold level. However, at 30%,
South America had the greatest amount of land available, and a large change in available land area, which increased by almost
five times compared to what was available at the 10% threshold. The area available in Africa increased by a factor of 5.5.
Central America showed the largest increase, to almost 10 times more at the 30% threshold. By contrast, within Asia, the area
increase was comparatively less, but still the area nearly doubled. Globally, a low threshold of 10% crown cover excluded
almost 2/3 of the land identified that was eligible at 30%, over 5 million km2. The spatial analyses showed not only the effects of the choice of the crown cover criterion, but also where the land was
available for CDM activities within each country at different thresholds. Protected areas account for 10–20% of the CDM-AR
eligible area in most countries. 相似文献
192.
Grohé C Chaimanee Y de Bonis L Yamee C Blondel C Jaeger JJ 《Die Naturwissenschaften》2010,97(11):1003-1015
We report new dental remains of Mustelidae from the late middle Miocene of Mae Moh Basin, northern Thailand, improving the
poor fossil record of the family in Southeast Asia. Siamogale thailandica is a poorly known mustelid, previously recorded from just a single tooth. Here we present over a hundred new specimens attributable
to this species. S. thailandica shows a combination of primitive and convergent features of the dentition that makes its original subfamilial assignment
to Lutrinae doubtful. Evidence from the dental morphology suggests that it belongs to a bunodont otter-like mustelid that
evolved in convergence with “true” otters (Lutrinae) toward a semi-aquatic way of life. Autapomorphic features such as the
height and the position of the m1 metaconid and the shape of the P4 lingual shelf make S. thailandica unique among Mustelidae. The morphology of this species is mostly similar to Mionictis species and Lartetictis dubia, reported in the Miocene of North America and Europe, respectively. These similarities could imply immigration events to
Thailand in the early or middle Miocene. Alternately, the lineage leading to Siamogale might have deeper origins from an endemic early Miocene Southeast Asian mustelid. 相似文献
193.
Testing the robustness of management decisions to uncertainty: Everglades restoration scenarios. 总被引:2,自引:0,他引:2
Michael M Fuller Louis J Gross Scott M Duke-Sylvester Mark Palmer 《Ecological applications》2008,18(3):711-723
To effectively manage large natural reserves, resource managers must prepare for future contingencies while balancing the often conflicting priorities of different stakeholders. To deal with these issues, managers routinely employ models to project the response of ecosystems to different scenarios that represent alternative management plans or environmental forecasts. Scenario analysis is often used to rank such alternatives to aid the decision making process. However, model projections are subject to uncertainty in assumptions about model structure, parameter values, environmental inputs, and subcomponent interactions. We introduce an approach for testing the robustness of model-based management decisions to the uncertainty inherent in complex ecological models and their inputs. We use relative assessment to quantify the relative impacts of uncertainty on scenario ranking. To illustrate our approach we consider uncertainty in parameter values and uncertainty in input data, with specific examples drawn from the Florida Everglades restoration project. Our examples focus on two alternative 30-year hydrologic management plans that were ranked according to their overall impacts on wildlife habitat potential. We tested the assumption that varying the parameter settings and inputs of habitat index models does not change the rank order of the hydrologic plans. We compared the average projected index of habitat potential for four endemic species and two wading-bird guilds to rank the plans, accounting for variations in parameter settings and water level inputs associated with hypothetical future climates. Indices of habitat potential were based on projections from spatially explicit models that are closely tied to hydrology. For the American alligator, the rank order of the hydrologic plans was unaffected by substantial variation in model parameters. By contrast, simulated major shifts in water levels led to reversals in the ranks of the hydrologic plans in 24.1-30.6% of the projections for the wading bird guilds and several individual species. By exposing the differential effects of uncertainty, relative assessment can help resource managers assess the robustness of scenario choice in model-based policy decisions. 相似文献
194.
Li Yafei Zhou Can Wang Shizhong Lin Qingqi Ni Zhuobiao Qiu Hao Morel Jean Louis Qiu Rongliang 《Environmental science and pollution research international》2019,26(25):25985-25999
Environmental Science and Pollution Research - The large-scale use of quaternary ammonium compounds (QACs) in medicines or disinfectants can lead to their release into the environment, posing a... 相似文献
195.
196.
Hardiman Nigel Dietz Kristina Charlotte Bride Ian Passfield Louis 《Environmental management》2017,59(1):68-76
Environmental Management - Land managers of natural areas are under pressure to balance demands for increased recreation access with protection of the natural resource. Unintended dispersal of... 相似文献
197.
Work-contingent self-esteem (WCSE; the degree to which workers' self-esteem is based on workplace performance) has positive consequences for performance, yet less is known about its consequences for well-being. In this paper, we contribute to the literature on WCSE by examining the mechanisms through which it impacts well-being at work and outside of work. We challenge contingent self-esteem (CSE) theory (Crocker & Park, 2004), which argues that CSE negatively impacts well-being by fostering internally controlled (introjected) motivation and diminishing autonomous motivation, by suggesting that WCSE fosters autonomous and internally controlled motivation and thus has both beneficial and harmful effects on well-being. We also expand CSE theory by suggesting that WCSE can negatively impact well-being outcomes by causing work–nonwork conflict. Results from a time-separated design in a sample of full-time employees supported our arguments, revealing that WCSE impacted well-being at work through both autonomous and internally controlled work motivations. WCSE also had negative effects on well-being at and outside of work through work–nonwork conflict. The beneficial effects of WCSE outweighed its harmful effects on job satisfaction and neutralized its harmful effects for all other outcomes. We discuss theoretical implications for CSE theory, self-determination theory, and work–nonwork issues and note important practical implications. 相似文献
198.
Polygodial is a drimane sesquiterpene dialdehyde derived from certain terrestrial plant species that potently inhibits ascidian metamorphosis, and thus has potential for controlling fouling ascidians in bivalve aquaculture. The current study examined the effects of polygodial on a range of biochemical biomarkers of oxidative stress and detoxification effort in the gills of adult Perna canaliculus Gmelin. Despite high statistical power and the success of positive controls, the antioxidant enzymes glutathione reductase (GR), glutathione peroxidase (GPOX), catalase (CAT), and superoxide dismutase (SOD); thiol status, as measured by total glutathione (GSH-t), glutathione disulphide (GSSG), and GSH-t/GSSG ratio; end products of oxidative damage, lipid hydroperoxides (LHPO) and protein carbonyls; and detoxification pathways, represented by GSH-t and glutathione S-transferase (GST), were unaffected in the gills of adult P. canaliculus exposed to polygodial at 0.1 or 1 × the 99% effective dose in fouling ascidians (IC99). Similarly, GR levels, thiol status, and detoxification activities were unaffected in mussels exposed to polygodial at 10 × the IC99, although GPOX, CAT, and SOD activities increased. However, the increases were small relative to positive controls, no corresponding oxidative damage was detected, and this concentration greatly exceeds effective doses required to inhibit fouling ascidians in aquaculture. These findings compliment a previous study that established the insensitivity to polygodial of P. canaliculus growth, condition, and mitochondrial functioning, providing additional support for the suitability of polygodial for use as an antifouling agent in bivalve aquaculture. 相似文献
199.
Roy O. McCaldin Louis W. Johnson 《Journal of the Air & Waste Management Association (1995)》2013,63(6):405-409
An instrumented single engine aircraft is being used to characterize plumes from large emission sources. By cross sectioning these plumes at a number of points we hope to describe the character and concentration of pollution as it ages and travels downwind under known meteorological conditions. This paper reports experimental work thus far completed on aerosol measurement. Flights have been made through plumes from a large coal-fired power station, forest fires, and a gravel plant. Particle counts in various size classifications were made with a Bausch and Lomb 40–1 Dust Counter which was carried in the aircraft. Selected meteorological parameters were recorded. Results show the aerosol concentrations in various size classifications that are found at successive distances downwind from these sources for distances up to 32 miles. Background aerosol concentrations are also reported, and variations in these can be noted with respect to time, location and altitude. 相似文献
200.