全文获取类型
收费全文 | 186篇 |
免费 | 3篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 11篇 |
废物处理 | 4篇 |
环保管理 | 27篇 |
综合类 | 47篇 |
基础理论 | 29篇 |
污染及防治 | 54篇 |
评价与监测 | 13篇 |
社会与环境 | 9篇 |
出版年
2023年 | 4篇 |
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 10篇 |
2016年 | 17篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 17篇 |
2012年 | 12篇 |
2011年 | 18篇 |
2010年 | 8篇 |
2009年 | 11篇 |
2008年 | 9篇 |
2007年 | 9篇 |
2006年 | 11篇 |
2005年 | 4篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 3篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1966年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有194条查询结果,搜索用时 0 毫秒
31.
The Arctic experiences a high-radiation environment in the summer with 24-hour daylight for more than two months. Damage to plants and ecosystem metabolism can be muted by overcast conditions common in much of the Arctic. However, with climate change, extreme dry years and clearer skies could lead to the risk of increased photoxidation and photoinhibition in Arctic primary producers. Mosses, which often exceed the NPP of vascular plants in Arctic areas, are often understudied. As a result, the effect of specific environmental factors, including light, on these growth forms is poorly understood. Here, we investigated net ecosystem exchange (NEE) at the ecosystem scale, net Sphagnum CO2 exchange (NSE), and photoinhibition to better understand the impact of light on carbon exchange from a moss-dominated coastal tundra ecosystem during the summer season 2006. Sphagnum photosynthesis showed photoinhibition early in the season coupled with low ecosystem NEE. However, later in the season, Sphagnum maintained a significant CO2 uptake, probably for the development of subsurface moss layers protected from strong radiation. We suggest that the compact canopy structure of Sphagnum reduces light penetration to the subsurface layers of the moss mat and thereby protects the active photosynthetic tissues from damage. This stress avoidance mechanism allowed Sphagnum to constitute a significant percentage (up to 60%) of the ecosystem net daytime CO2 uptake at the end of the growing season despite the high levels of radiation experienced. 相似文献
32.
Irene Cheng Julia Lu Xinjie Song 《Atmospheric environment (Oxford, England : 1994)》2009,43(39):6145-6158
This study identified sources of mercury (Hg) in downtown Toronto, Canada by analyzing gaseous elemental mercury (GEM), mercury associated with particles with sizes less than 2.5 microns (PHg < 2.5), and gaseous oxidized inorganic mercury (GOIM), commonly referred to as reactive gaseous mercury (RGM), and air pollutants (CO, NOx, O3, PM2.5, SO2) concentrations between Dec 2003 and Nov 2004. The data were analyzed using Positive Matrix Factorization (PMF) model, Principal Components Analysis (PCA), ratio analysis, back trajectories, and correlation analyses. The analyses suggest industrial sources (chemical production, metal production, sewage treatment), rather than coal combustion, were the major contributors to measured Hg levels. Overlap in source profiles for the Hg sources listed in the Canadian National Pollutant Release Inventory (NPRI) and lack of source profiles for urban sources were the major limitations to positively identifying sources from the PMF and PCA factors. Correlation analyses revealed direct emissions were the sources of GOIM in spring, summer, and fall, and the occurrence of GEM oxidation by ozone in the summer. Elevated Hg events are attributed to emissions from urban sources near the sampling site, regional point sources, and photochemical processes involving ozone. 相似文献
33.
34.
Irene M. van den Heuvel Michael I. Cherry Georg M. Klump 《Behavioral ecology and sociobiology》2014,68(3):373-381
Crimson-breasted shrikes produce duets which are used in interactions with neighbours and intruders. We examined two major hypotheses explaining duetting, the territorial defence and mate guarding hypotheses, using playback experiments. The responses of 12 pairs towards solo male, solo female and stereo duet playback were analysed using principal component analysis and ANOVA. The measures of response intensity revealed in most cases highly coordinated responses of the pair partners. Although these joint responses could suggest cooperative territorial defence or mutual mate defence, responses to the treatments differed between males and females in terms of three variables. Females increased their answer rates significantly in response to unpaired female intruders, compared to unpaired male intruders. During duet playback, females directed their responses equally at both intruding pair members. In contrast, males were equally responsive towards unpaired male intruders and intruding pairs, but in the latter case directed their responses at the male pair member. In the presence of unpaired female intruders, males increased their solo song rates, but in the presence of intruding pairs, they increased overlapping rates and duetted with their mates. These divergent responses suggest that females use duets for mate guarding against unpaired females, whereas males use solo songs for mate guarding and both solos and duets in territorial defence. 相似文献
35.
36.
Dimitrakopoulos PG Siamantziouras AS Galanidis A Mprezetou I Troumbis AY 《Environmental management》2006,37(6):826-839
We conducted a field experiment using constructed communities to test whether species richness contributed to the maintenance
of ecosystem processes under fire disturbance. We studied the effects of diversity components (i.e., species richness and
species composition) upon productivity, structural traits of vegetation, decomposition rates, and soil nutrients between burnt
and unburnt experimental Mediterranean grassland communities. Our results demonstrated that fire and species richness had
interactive effects on aboveground biomass production and canopy structure components. Fire increased biomass production of
the highest-richness communities. The effects of fire on aboveground biomass production at different levels of species richness
were derived from changes in both vertical and horizontal canopy structure of the communities. The most species-rich communities
appeared to be more resistant to fire in relation to species-poor ones, due to both compositional and richness effects. Interactive
effects of fire and species richness were not important for belowground processes. Decomposition rates increased with species
richness, related in part to increased levels of canopy structure traits. Fire increased soil nutrients and long-term decomposition
rate. Our results provide evidence that composition within richness levels had often larger effects on the stability of aboveground
ecosystem processes in the face of fire disturbance than species richness per se. 相似文献
37.
38.
Sánchez-Gavilán Irene Rufo Lourdes Rodríguez Nuria de la Fuente Vicenta 《Environmental science and pollution research international》2021,28(3):2719-2727
Environmental Science and Pollution Research - A complete survey is presented on the inorganic composition of the euhalophyte annual succulent species Salicornia patula (Chenopodiaceae), including... 相似文献
39.
A procedure for the quantification of the PCB marker congeners 28, 52, 101, 138, 153, 180 in plastic waste form the recycling of cables in the range of content between 0.1 mgkg(-1) and 20 mgkg(-1) was validated. Representative reference materials for laboratory analyses were produced using granulates from different recycling processes. The method development included aspects of grinding, sieving, homogenising as well as the comparison of extraction methods and chromatographic conditions. The validated procedure foresees grinding of the technical sample to an upper particle size limit of 0.50mm followed by extraction with an unpolar solvent such as n-hexane and gas chromatographic determination. LOD and LOQ for individual congeners ranged between 0.01 mgkg(-1) and 0.08 mgkg(-1). Electron capture detection (ECD) and mass selective detection (MS) were equivalent if chromatographic conditions were appropriately selected. The application of MS was advantageous in presence of significant amounts of interfering components which have been found in some cables. Three reference materials containing the marker congeners in the range of 0.1 mgkg(-1)-5 mgkg(-1) were submitted to a final validation intercomparison with 23 selected field laboratories using the developed method. Relative reproducibility standard deviations varied between 15% and 33%. 相似文献
40.
Irene Zorrilla Rosa Martinez Mark A. Taggart Ngaio Richards 《Conservation biology》2015,29(2):587-592
Exposure to residues of the nonsteroidal anti‐inflammatory drug (NSAID) diclofenac present in livestock carcasses has caused extensive declines in 3 Gyps vulture species across Asia. The carcass of a wild Eurasian Griffon Vulture (Gyps fulvus) was found in 2012 on an Andalucian (Spain) game hunting reserve and examined forensically. The bird had severe visceral gout, a finding consistent with Gyps vultures from Asia that have been poisoned by diclofenac. Liver and kidney samples from this Eurasian Griffon Vulture contained elevated flunixin (an NSAID) levels (median = 2.70 and 6.50 mg/kg, respectively). This is the first reported case of a wild vulture being exposed to and apparently killed by an NSAID outside Asia. It is also the first reported instance of mortality in the wild resulting from environmental exposure to an NSAID other than diclofenac. Caso de Sospecha de Envenenamiento por Flunixin de un Buitre Leonado en España 相似文献