全文获取类型
收费全文 | 435篇 |
免费 | 5篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 18篇 |
废物处理 | 16篇 |
环保管理 | 43篇 |
综合类 | 109篇 |
基础理论 | 78篇 |
环境理论 | 1篇 |
污染及防治 | 138篇 |
评价与监测 | 25篇 |
社会与环境 | 15篇 |
灾害及防治 | 2篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 11篇 |
2020年 | 8篇 |
2019年 | 5篇 |
2018年 | 13篇 |
2017年 | 15篇 |
2016年 | 14篇 |
2015年 | 13篇 |
2014年 | 9篇 |
2013年 | 24篇 |
2012年 | 25篇 |
2011年 | 28篇 |
2010年 | 21篇 |
2009年 | 21篇 |
2008年 | 20篇 |
2007年 | 28篇 |
2006年 | 14篇 |
2005年 | 23篇 |
2004年 | 12篇 |
2003年 | 8篇 |
2002年 | 12篇 |
2001年 | 6篇 |
2000年 | 8篇 |
1999年 | 11篇 |
1998年 | 2篇 |
1997年 | 8篇 |
1996年 | 3篇 |
1995年 | 9篇 |
1994年 | 7篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1967年 | 2篇 |
1964年 | 3篇 |
1963年 | 2篇 |
1961年 | 2篇 |
1960年 | 3篇 |
1955年 | 3篇 |
排序方式: 共有445条查询结果,搜索用时 625 毫秒
331.
Vulturius Gregor André Karin Swartling Åsa Gerger Brown Calum Rounsevell Mark D. A. Jönsson Anna Maria Blanco Victor 《Regional Environmental Change》2018,18(5):1571-1571
Regional Environmental Change - The published online version contains mistake. Anna Maria Jönsson was inadvertently omitted in the author group section. Correct author group section is shown... 相似文献
332.
Uffe Høgsbro Thygesen Christoffer Moesgaard Albertsen Casper Willestofte Berg Kasper Kristensen Anders Nielsen 《Environmental and Ecological Statistics》2017,24(2):317-339
Many statistical models in ecology follow the state space paradigm. For such models, the important step of model validation rarely receives as much attention as estimation or hypothesis testing, perhaps due to lack of available algorithms and software. Model validation is often based on a naive adaptation of Pearson residuals, i.e. the difference between observations and posterior means, even if this approach is flawed. Here, we consider validation of state space models through one-step prediction errors, and discuss principles and practicalities arising when the model has been fitted with a tool for estimation in general mixed effects models. Implementing one-step predictions in the R package Template Model Builder, we demonstrate that it is possible to perform model validation with little effort, even if the ecological model is multivariate, has non-linear dynamics, and whether observations are continuous or discrete. With both simulated data, and a real data set related to geolocation of seals, we demonstrate both the potential and the limitations of the techniques. Our results fill a need for convenient methods for validating a state space model, or alternatively, rejecting it while indicating useful directions in which the model could be improved. 相似文献
333.
Small farm ponds: overlooked features with important impacts on watershed sediment transport
下载免费PDF全文
![点击此处可从《Journal of the American Water Resources Association》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Matthew D. Berg Sorin C. Popescu Bradford P. Wilcox Jay P. Angerer Edward C. Rhodes Jason McAlister William E. Fox 《Journal of the American Water Resources Association》2016,52(1):67-76
Despite their size, small farm ponds are important features in many landscapes. Yet hydrographical databases often fail to capture these ponds, and their impacts on watershed processes remain unclear. For a 230‐km2 portion of central Texas, United States (U.S.), we created a historical inventory of ponds and quantified the accuracy of automated detection methods under varying drought conditions. In addition, we documented pond dredging/enlargement events and identified sites that had been abandoned. We also analyzed sediment cores from downstream reservoirs to track changes in watershed sediment transport. Over 75 years, pond densities increased more than 350% — to among the highest documented in the U.S. — and the ability of automated methods to detect these ponds was highly dependent on drought severity (R2 = 0.96). Approximately 5% of ponds present in the 1950s were no longer present in 2012, while 33% were dredged between 1937 and 2012. Downstream reservoir sedimentation has decreased by an average of 55% as ponds have increased in number. These findings suggest that small ponds and the maintenance of trapping efficiency have large‐scale impacts on sediment dynamics. Accurately accounting for these storage effects is vital to water resource planning efforts. 相似文献
334.
Camilla Sandström Annika Carlsson-Kanyama Karin Beland Lindahl Karin Mossberg Sonnek Annika Mossing Annika Nordin Eva-Maria Nordström Riitta Räty 《Ambio》2016,45(2):100-108
Conflicting perspectives on forests has for a long time challenged forest policy development in Sweden. Disagreements about forest futures create intractable deadlocks when stakeholders talk past each other. The purpose of this study is to move beyond this situation through the application of participatory backcasting. By comparing visions of the future forest among stakeholder groups, we highlight contemporary trajectories and identify changes that were conceived as desirable. We worked with four groups: the Biomass and Bioenergy group, the Conservation group, the Sami Livelihood group and the Recreation and Rural Development group; in total representatives from 40 organizations participated in workshops articulating the groups’ visions. Our results show well-known tensions such as intrinsic versus instrumental values but also new ones concerning forests’ social values. Identified synergies include prioritization of rural development, new valued-added forest products and diversified forest management. The results may feed directly into forest policy processes facilitating the process and break current deadlocks. 相似文献
335.
van den Berg F Tiktak A Heuvelink GB Burgers SL Brus DJ de Vries F Stolte J Kroes JG 《Journal of environmental quality》2012,41(1):253-261
In the new Dutch decision tree for the evaluation of pesticide leaching to groundwater, spatially distributed soil data are used by the GeoPEARL model to calculate the 90th percentile of the spatial cumulative distribution function of the leaching concentration in the area of potential usage (SP90). Until now it was not known to what extent uncertainties in soil and pesticide properties propagate to spatially aggregated parameters like the SP90. A study was performed to quantify the uncertainties in soil and pesticide properties and to analyze their contribution to the uncertainty in SP90. First, uncertainties in the soil and pesticide properties were quantified. Next, a regular grid sample of points covering the whole of the agricultural area in the Netherlands was randomly selected. At the grid nodes, realizations from the probability distributions of the uncertain inputs were generated and used as input to a Monte Carlo uncertainty propagation analysis. The analysis showed that the uncertainty concerning the SP90 is 10 times smaller than the uncertainty about the leaching concentration at individual point locations. The parameters that contribute most to the uncertainty about the SP90 are, however, the same as the parameters that contribute most to uncertainty about the leaching concentration at individual point locations (e.g., the transformation half-life in soil and the coefficient of sorption on organic matter). Taking uncertainties in soil and pesticide properties into account further leads to a systematic increase of the predicted SP90. The important implication for pesticide regulation is that the leaching concentration is systematically underestimated when these uncertainties are ignored. 相似文献
336.
Forest Fragmentation and Landscape Transformation in a Reindeer Husbandry Area in Sweden 总被引:1,自引:0,他引:1
Reindeer husbandry and forestry are two main land users in boreal forests in northern Sweden. Modern forestry has numerous
negative effects on the ground-growing and arboreal lichens that are crucial winter resources for reindeer husbandry. Using
digitized historical maps, we examined changes in the forest landscape structure during the past 100 years, and estimated
corresponding changes in suitability of forest landscape mosaics for the reindeer winter grazing. Cover of old coniferous
forests, a key habitat type of reindeer herding system, showed a strong decrease during the study period, whereas clear-cutting
and young forests increased rapidly in the latter half of the 20th century. The dominance of young forests and fragmentation
of old-growth forests (decreased patch sizes and increased isolation) reflect decreased amount of arboreal lichens as well
as a lowered ability of the landscape to sustain long-term persistence of lichens. The results further showed that variation
in ground lichen cover among sites was mainly related to soil moisture conditions, recent disturbances, such as soil scarification
and prescribed burning, and possibly also to forest history. In general, the results suggest that the composition and configuration
of the forest landscape mosaic has become less suitable for sustainable reindeer husbandry. 相似文献
337.
Karin C.H.J. Smolders Yvonne A.W. de Kort Ariadne D. Tenner Florian G. Kaiser 《Journal of environmental psychology》2012
At work, people may experience fatigue and a depletion of mental resources. The subsequent need for recovery is generally assessed employing subjective reports on evaluative statements. In this paper, we explore whether it is possible to assess employees’ recovery needs with a systematic inspection of behaviors. The idea is based on Campbell’s paradigm (Kaiser, Byrka, & Hartig, 2010), which holds that individuals will perform more, and more difficult behaviors to recover from fatigue when their need for recovery is higher. 相似文献
338.
Anette Jægerfeldt Baisner Jonas Lembcke Andersen Anders Findsen Simon Wilhelm Yde Granath Karin Ølgaard Madsen Mark Desholm 《Environmental management》2010,46(5):801-808
An increased focus on renewable energy has led to the planning and construction of marine wind farms in Europe. Since several terrestrial studies indicate that raptors are especially susceptible to wind turbine related mortality, a Spatial Planning Tool is needed so that wind farms can be sited, in an optimal way, to minimize risk of collisions. Here we use measurements of body mass, wingspan and wing area of eight European raptor species, to calculate their Best Glide Ratio (BGR). The BGR was used to construct a linear equation, which, by the use of initial take-off altitude, could be used to calculate a Theoretical Maximum Distance (TMD) from the coast, attained by these soaring-gliding raptor species. If the nearest turbine, of future marine wind farms, is placed farther away from the coast than the estimated TMD, the collision risk between the turbine blades and these gliding raptors will be minimized. The tool was demonstrated in a case study at the Rødsand II wind farm in Denmark. Data on raptor migration altitude were gathered by radar. From the TMD attained by registered soaring-gliding raptors in the area, we concluded that the Rødsand II wind farm is not sited ideally, from an ornithological point of view, as potentially all three registered species are at risk of gliding through the area swept by the turbine rotor blades, and thereby at risk of colliding with the wind turbines. 相似文献
339.
340.
Cornelissen G Cousins IT Wiberg K Tysklind M Holmström H Broman D 《Chemosphere》2008,72(10):1455-1461
The influence of black carbon (BC) on the sorption of 17 native polychlorinated-p-dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) was studied in five soil samples from a sawmill site where wood used to be impregnated with chlorophenol preservatives. The presence of BC caused measured total organic carbon (TOC)-water distribution ratios (K(TOC)) to be a median factor of 51 (interquartile range 18-68, n=85) higher than modeled amorphous organic carbon (AOC)-water distribution ratios (K(AOC)). K(TOC) was a factor of 73+/-27 above K(AOC) for PCDFs (n=10) and a factor of 20+/-13 (n=7) for PCDDs. The reason for this difference is probably that attaining a planar configuration after sorption to BC is less thermodynamically favorable for PCDDs than for PCDFs. BC-water distribution ratios were calculated from K(TOC), K(AOC) and BC contents, and ranged from 10(9.9) (2,3,7,8-Tetra-CDD) to 10(11.5) l kg(-1) (Octa-CDF). More than 90% of the PCDD/Fs in the soil was calculated to be BC-sorbed. Dissolved organic carbon (DOC)-water distribution ratios were measured to be in the same order of magnitude as K(AOC). This study shows that strong sorption to BC should be included when assessing ecotoxicological risk or modeling transport to groundwater of PCDD/Fs in soil. 相似文献