全文获取类型
收费全文 | 94篇 |
免费 | 1篇 |
专业分类
安全科学 | 1篇 |
废物处理 | 6篇 |
环保管理 | 12篇 |
综合类 | 5篇 |
基础理论 | 50篇 |
环境理论 | 1篇 |
污染及防治 | 13篇 |
评价与监测 | 4篇 |
社会与环境 | 3篇 |
出版年
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 10篇 |
2012年 | 5篇 |
2011年 | 7篇 |
2010年 | 2篇 |
2009年 | 5篇 |
2008年 | 8篇 |
2007年 | 9篇 |
2006年 | 1篇 |
2005年 | 1篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1994年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1915年 | 1篇 |
排序方式: 共有95条查询结果,搜索用时 203 毫秒
81.
Breena Holland 《环境政策》2017,26(3):391-412
Climate adaptation politics presents both obstacles and opportunities for correcting inequities that leave some communities especially vulnerable to climate-related environmental harms. By revealing these obstacles and opportunities, theories of procedural justice can help to identify procedural reforms and political strategies that advance the interests of vulnerable populations. An account of procedural justice is proposed that foregrounds the capability for political control over one’s environment, defined as having the political power to influence adaptation decisions. While the variables shaping this capability in the politics of environmental injustice often interact in ways that reproduce environmental inequities, adaptation politics has the potential to produce more transformational outcomes. To illustrate this potential, differences between the politics of environmental injustice and the politics of climate adaptation are drawn on to sketch the basic features of a typology of vulnerable populations’ political capabilities in the politics of climate adaptation, before highlighting the potential points for intervention. 相似文献
82.
Representative Landscapes in the Forested Area of Canada 总被引:1,自引:0,他引:1
Canada is a large nation with forested ecosystems that occupy over 60% of the national land base, and knowledge of the patterns
of Canada’s land cover is important to proper environmental management of this vast resource. To this end, a circa 2000 Landsat-derived
land cover map of the forested ecosystems of Canada has created a new window into understanding the composition and configuration
of land cover patterns in forested Canada. Strategies for summarizing such large expanses of land cover are increasingly important,
as land managers work to study and preserve distinctive areas, as well as to identify representative examples of current land-cover
and land-use assemblages. Meanwhile, the development of extremely efficient clustering algorithms has become increasingly
important in the world of computer science, in which billions of pieces of information on the internet are continually sifted
for meaning for a vast variety of applications. One recently developed clustering algorithm quickly groups large numbers of
items of any type in a given data set while simultaneously selecting a representative—or “exemplar”—from each cluster. In
this context, the availability of both advanced data processing methods and a nationally available set of landscape metrics
presents an opportunity to identify sets of representative landscapes to better understand landscape pattern, variation, and
distribution across the forested area of Canada. In this research, we first identify and provide context for a small, interpretable
set of exemplar landscapes that objectively represent land cover in each of Canada’s ten forested ecozones. Then, we demonstrate
how this approach can be used to identify flagship and satellite long-term study areas inside and outside protected areas
in the province of Ontario. These applications aid our understanding of Canada’s forest while augmenting its management toolbox,
and may signal a broad range of applications for this versatile approach. 相似文献
83.
Impact of alternative metrics on estimates of extent of occurrence for extinction risk assessment
下载免费PDF全文
![点击此处可从《Conservation biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Lucas N. Joppa Stuart H. M. Butchart Michael Hoffmann Steve P. Bachman H. Resit Akçakaya Justin F. Moat Monika Böhm Robert A. Holland Adrian Newton Beth Polidoro Adrian Hughes 《Conservation biology》2016,30(2):362-370
In International Union for Conservation of Nature (IUCN) Red List assessments, extent of occurrence (EOO) is a key measure of extinction risk. However, the way assessors estimate EOO from maps of species’ distributions is inconsistent among assessments of different species and among major taxonomic groups. Assessors often estimate EOO from the area of mapped distribution, but these maps often exclude areas that are not habitat in idiosyncratic ways and are not created at the same spatial resolutions. We assessed the impact on extinction risk categories of applying different methods (minimum convex polygon, alpha hull) for estimating EOO for 21,763 species of mammals, birds, and amphibians. Overall, the percentage of threatened species requiring down listing to a lower category of threat (taking into account other Red List criteria under which they qualified) spanned 11–13% for all species combined (14–15% for mammals, 7–8% for birds, and 12–15% for amphibians). These down listings resulted from larger estimates of EOO and depended on the EOO calculation method. Using birds as an example, we found that 14% of threatened and near threatened species could require down listing based on the minimum convex polygon (MCP) approach, an approach that is now recommended by IUCN. Other metrics (such as alpha hull) had marginally smaller impacts. Our results suggest that uniformly applying the MCP approach may lead to a one‐time down listing of hundreds of species but ultimately ensure consistency across assessments and realign the calculation of EOO with the theoretical basis on which the metric was founded. 相似文献
84.
A Bayesian hierarchical space-time model is proposed by combining information from real-time ambient AIRNow air monitoring
data, and output from a computer simulation model known as the Community Multi-scale Air Quality (Eta-CMAQ) forecast model.
A model validation analysis shows that the model predicted maps are more accurate than the maps based solely on the Eta-CMAQ
forecast data for a 2 week test period. These out-of sample spatial predictions and temporal forecasts also outperform those
from regression models with independent Gaussian errors. The method is fully Bayesian and is able to instantly update the
map for the current hour (upon receiving monitor data for the current hour) and forecast the map for several hours ahead.
In particular, the 8 h average map which is the average of the past 4 h, current hour and 3 h ahead is instantly obtained
at the current hour. Based on our validation, the exact Bayesian method is preferable to more complex models in a real-time
updating and forecasting environment. 相似文献
85.
Erich M. G. Fitzgerald Matthew T. Carrano Timothy Holland Barbara E. Wagstaff David Pickering Thomas H. Rich Patricia Vickers-Rich 《Die Naturwissenschaften》2012,99(5):397-405
The basal theropod dinosaur clade Ceratosauria, and its subclade Abelisauroidea, is characteristic of late Mesozoic terrestrial vertebrate faunas in western Gondwana (South America, Africa, Madagascar, and India) and Europe. Yet unambiguous records of ceratosaurs have hitherto been absent from Australia, where the theropod assemblage appears to include several typically Laurasian clades. Here, we report the first evidence of ceratosaurs (and potentially abelisauroids) from eastern Gondwana––a diagnostic astragalocalcaneum from the Aptian (121–125?Ma) of Victoria, Australia. Ceratosauria thus occurred in both western and eastern Gondwana during the Early Cretaceous. This fossil adds to the poorly known dinosaur fauna of Australia, a major clade of basal theropods, emphasising that its mid-Cretaceous theropod diversity was surprisingly cosmopolitan despite relative geographic isolation, including clades that have been thought to be typical of both Gondwana and Laurasia––Ceratosauria, Spinosauridae, Carcharodontosauria, Tyrannosauroidea, and Deinonychosauria. Such a contemporaneous association of theropod clades is unknown from other Gondwanan continents and questions the views that the late Mesozoic dinosaur fauna of Australia was dominated by Gondwanan or Laurasian elements, extreme isolation, relictualism, and/or novelty as a ‘centre of origin’. The cosmopolitan theropod fauna of Australia probably reflects the global distribution of these clades early in their history, prior to significant continental breakup. 相似文献
86.
Rose M Harrison N Greaves A Dowding A Runacres S Gem M Fernandes A White S Duff M Costley C Leon I Petch RS Holland J Chapman A 《Journal of environmental monitoring : JEM》2005,7(4):378-383
To control the outbreak of foot and mouth disease, which occurred in the UK in early 2001, a large number of farm animals were slaughtered. Where it was not possible to render or landfill the carcasses, they were destroyed by burning on open pyres, with wood, coal and other materials. Uncontrolled combustion such as this is known to produce small quantities of dioxins and an investigation was made into whether, as a result of the burning, there was an elevation in the concentrations of these compounds in food produced in the areas close to the pyres. With few exceptions, concentrations of PCDD/Fs and PCBs were within the expected ranges as predicted by reference data. No accumulation over time was evident from a repeat milk sampling exercise. Where elevated concentrations of PCDD/Fs and PCBs were found in chickens and eggs, they were in samples not destined for the food chain. Elevated levels in some samples of milk from Dumfries and Galloway were not found in earlier or later samples and may have been found as a result of a temporary feeding regime. Elevated concentrations in lamb from Carmarthenshire were from very young animals which would not have entered the food chain. There was no evidence of any significant increase in dietary exposure to PCDD/Fs and PCBs as a result of the FMD pyres. 相似文献
87.
The rapid rate of development in the South Carolina (SC) coastal zone has heightened public concern for the condition of the state's estuaries, and alerted scientists to the potential that novel and adverse effects on estuarine ecosystems may result. Although well-developed databases from long-term monitoring programs exist for many variables valuable in predicting and following system responses, information on phytoplankton distributions in SC estuaries has lagged. Knowledge of the dynamical relationship between environmental (e.g., nutrient quantity and quality) and biological (e.g., grazing) regulation, and phytoplankton biomass and composition is critical to understanding estuarine susceptibility to eutrophication or harmful algal blooms (HABs). Recently, SC scientists from federal, state, and academic institutions established a collaborative monitoring program to assess HAB distribution and ecology statewide. The South Carolina Harmful Algal Bloom Program includes: a) intensive temporal monitoring at areas of known HAB occurrence or those exhibiting symptoms potentially related to HABs (e.g., prevalent fish lesions), b) extensive spatial monitoring in coordination with existing statewide efforts, c) a citizen volunteer monitoring network, d) nutrient response bioassays, and e) laboratory-based physiological experiments on HAB isolates. By combining trip-wire surveillance and rapid response systems, routine monitoring of environmental parameters and HAB distribution, and process-oriented studies examining the physiological functioning of HAB species, an enhanced understanding of the impact and environmental control of HABs in SC estuaries will be achieved. The application of this approach to studies on the distribution and physiological ecology of a new widespread SC red tide, and to the discovery of several potentially toxic blooms (including Pfiesteria) in SC holding ponds, are described. 相似文献
88.
We examined the inheritance of theMytilus edulis CaM-1 Intron 3 locus, a non-coding DNA locus with two potentially neutral length-variants. The polymerase chain reaction (PCR) was used to determine theCaM-1 genotype for 799 larvae obtained from 11 laboratory crosses. Larvae were typed singly only 8 to 24 h after fertilization. We find evidence that each allele can be inherited from either sex, that there are no barriers to fertilization between gametes of different genotypes, and that most larvae have genotypes compatible with Mendelian inheritance of the locus. Deviations from expected genotype frequencies were found in some crosses; we suggest that a contributing factor is aneuploidy in early larvae, but a major cause is more likely to be selection at a locus linked toCaM-1, occurring under the artificial laboratory culture conditions. This study demonstrates the feasibility of applying molecular genetic techniques to early larval stages of marine bivalves, and presents a new non-destructive biopsy method for DNA analysis from living adult mussels. 相似文献
89.
PCR (polymerase chain reaction) amplification of non-coding introns in phylogenetically widespread genes, using DNA primers based on the conserved exon sequences, provides a widely applicable strategy for finding DNA polymorphisms in eukaryotic genomes. Polymorphisms in introns provide a new source of potentially neurtral genetic markers for use in population biology. Here we use this approach to design PCR primers for an intron of calmodulin genes. We show that there are at least two calmodulin genes in mussels of theMytilus edulis species complex, and using gene- and species-specific primers we resolve two alleles at a calmodulin intron locus. Population surveys using PcR of adult mussel DNA reveal that genotype frequencies at most sites surveyed in England, Scotland and Italy, conform to Hardy-Weinberg equilibrium, suggesting that this is a novel neutral genetic marker. The data also provide preliminary evidence for restricted gene flow between mussel populations on the west and northeast coasts of Britain, and for local effects around the Thames estuary. 相似文献
90.
Our comparative study of the knees of horses and cows (paraphrased as highly evolved joggers and as domesticated couch-potatoes, respectively) demonstrates significant differences in the posterior sections of bovine and equine tibial cartilage, which are consistent with specialisation for gait. These insights were possible using a novel analytical measuring technique based on the shearing of small biopsy samples, called dynamic shear analysis. We assert that this technique could provide a powerful new tool to precisely quantify the pathology of osteoarthritis for the medical field. 相似文献