全文获取类型
收费全文 | 19673篇 |
免费 | 215篇 |
国内免费 | 135篇 |
专业分类
安全科学 | 579篇 |
废物处理 | 788篇 |
环保管理 | 2398篇 |
综合类 | 5623篇 |
基础理论 | 4129篇 |
环境理论 | 6篇 |
污染及防治 | 4644篇 |
评价与监测 | 1052篇 |
社会与环境 | 707篇 |
灾害及防治 | 97篇 |
出版年
2018年 | 260篇 |
2017年 | 240篇 |
2016年 | 361篇 |
2015年 | 287篇 |
2014年 | 384篇 |
2013年 | 1371篇 |
2012年 | 469篇 |
2011年 | 663篇 |
2010年 | 604篇 |
2009年 | 677篇 |
2008年 | 689篇 |
2007年 | 731篇 |
2006年 | 654篇 |
2005年 | 556篇 |
2004年 | 577篇 |
2003年 | 554篇 |
2002年 | 510篇 |
2001年 | 663篇 |
2000年 | 462篇 |
1999年 | 322篇 |
1998年 | 239篇 |
1997年 | 232篇 |
1996年 | 225篇 |
1995年 | 258篇 |
1994年 | 278篇 |
1993年 | 236篇 |
1992年 | 244篇 |
1991年 | 255篇 |
1990年 | 266篇 |
1989年 | 238篇 |
1988年 | 192篇 |
1987年 | 196篇 |
1986年 | 195篇 |
1985年 | 197篇 |
1984年 | 210篇 |
1983年 | 202篇 |
1982年 | 208篇 |
1981年 | 230篇 |
1980年 | 182篇 |
1979年 | 192篇 |
1978年 | 153篇 |
1977年 | 149篇 |
1974年 | 153篇 |
1973年 | 149篇 |
1968年 | 157篇 |
1967年 | 186篇 |
1966年 | 159篇 |
1965年 | 150篇 |
1964年 | 155篇 |
1963年 | 144篇 |
排序方式: 共有10000条查询结果,搜索用时 570 毫秒
741.
International environmental agreements (IEAs) can coordinate abatement of transboundary pollutants. This paper investigates
how heterogeneous countries facing a stock pollutant might structure such an agreement. In particular, we examine how an IEA
might be implemented with a set of monetary transfers. The focus is on transfers that are time invariant, linear in emissions,
and consistent with budget balance. There is a range of such schemes that would induce efficient emissions. We provide a simple
and intuitive characterization of these penalties and describe how specific proposals might be chosen in order to facilitate
compliance and implementation. Our proposals are illustrated with a simple example. We show that heterogeneity reduces the
scope for penalty schemes to jointly satisfy desirable properties. 相似文献
742.
743.
Performance of newly implemented Environmental Management Systems in primary schools in South Africa
Luc Hens Torsten Wiedemann Schalk Raath Riana Stone Paul Renders Eric Craenhals 《Journal of environmental management》2010,91(4):906-917
Quantitative results from Environmental Management Systems (EMS) at primary schools have rarely been examined in literature. This paper presents the monitoring results of environmental care in 39 primary schools in Northern South Africa. During 2 years, after the EMS was implemented in the curriculum and in the school's management, the progress of environmental performances of the participating schools has been measured, by means of detailed questionnaires, related to four environmental aspects: water, waste, energy and greening. At the beginning of the project, 50% of the schools performed well on water-related environmental actions. Two years later it was 76%. For waste-related activities the improvement was even stronger: from 50% to 100%. The environmental performances of the schools improved also for greening-related actions, from 50% at the start of the project to 64% two years later. Only energy-related activities did not improve significantly with only 24% of all schools performing well at the end of the survey period.In general, the introduction of an EMS succeeded in an improvement of the overall environmental performances of the schools, but cost-intensive activities were less successful than others. 相似文献
744.
745.
Jamie R. Wood Janet M. Wilmshurst Trevor H. Worthy Avi S. Holzapfel Alan Cooper 《Conservation biology》2012,26(6):1091-1099
Late Quaternary extinctions and population fragmentations have severely disrupted animal‐plant interactions globally. Detection of disrupted interactions often relies on anachronistic plant characteristics, such as spines in the absence of large herbivores or large fruit without dispersers. However, obvious anachronisms are relatively uncommon, and it can be difficult to prove a direct link between the anachronism and a particular faunal taxon. Analysis of coprolites (fossil feces) provides a novel way of exposing lost interactions between animals (depositors) and consumed organisms. We analyzed ancient DNA to show that a coprolite from the South Island of New Zealand was deposited by the rare and threatened kakapo (Strigops habroptilus), a large, nocturnal, flightless parrot. When we analyzed the pollen and spore content of the coprolite, we found pollen from the cryptic root‐parasite Dactylanthus taylorii. The relatively high abundance (8.9% of total pollen and spores) of this zoophilous pollen type in the coprolite supports the hypothesis of a former direct feeding interaction between kakapo and D. taylorii. The ranges of both species have contracted substantially since human settlement, and their present distributions no longer overlap. Currently, the lesser short‐tailed bat (Mystacina tuberculata) is the only known native pollinator of D. taylorii, but our finding raises the possibility that birds, and other small fauna, could have once fed on and pollinated the plant. If confirmed, through experimental work and observations, this finding may inform conservation of the plant. For example, it may be possible to translocate D. taylorii to predator‐free offshore islands that lack bats but have thriving populations of endemic nectar‐feeding birds. The study of coprolites of rare or extinct taxonomic groups provides a unique way forward to expand existing knowledge of lost plant and animal interactions and to identify pollination and dispersal syndromes. This approach of linking paleobiology with neoecology offers significant untapped potential to help inform conservation and restoration plans. Un Eslabón Perdido entre un Loro No Volador y una Planta Parásita y el Papel Potencial de Coprolitos en Paleobiología de la Conservación 相似文献
746.
CSIRO Sustainable Ecosystems is constructing a spatially explicit modelling system capable of exploring alternative land and water policy alternatives against plausible price, cost, and climate scenarios for the next 20 years. INSIGHT will be used to identify the likely impacts of land and water policy options on regional economies and structural adjustment. Flowcharts have been constructed for most of the major crop and pasture and associated economic models for commodities produced in the Lachlan River Catchment of New South Wales. This enabled the most important components and interrelationships within these models to be readily identified. The next step has been to construct models at the regional scale that contain the essential elements of the more-detailed point models. The paper describes the progress to date in describing these models, and how they have been integrated into a coordinated agricultural crop production evaluation system. 相似文献
747.
Cindy DeForest Hauser Paul Battle Nina Mace 《Atmospheric environment (Oxford, England : 1994)》2009,43(10):1823-1826
Passive sampling devices are popular in applications which do not require the monitoring of hourly concentrations. Nitrogen oxides are often collected using filters coated with 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO). The filter extract can then be analyzed using flow injection analysis ion chromatography fitted with a copper/cadmium reduction column or UV–vis spectroscopy. When the latter is used to measure low concentrations of nitrogen oxides, absorbance by PTIO at the analytical wavelength of 545 nm contributes significantly. PTIO concentration on the filter also shows variation with filter storage and exposure time not accounted for in a single point blank subtraction at the analytical wavelength. A method is presented that uses a scaling factor to account for variations in concentration of PTIO on the field blank and provides a more accurate method for determining and correcting for the PTIO contribution to absorption when measuring ambient nitrogen oxide concentrations. 相似文献
748.
749.
The Role of Disaggregation of Asset Values in Flood Loss Estimation: A Comparison of Different Modeling Approaches at the Mulde River,Germany 总被引:3,自引:0,他引:3
Anja Wünsch Ulrich Herrmann Heidi Kreibich Annegret H. Thieken 《Environmental management》2009,44(3):524-541
In loss estimation there is a spatial mismatch of hazard data that are commonly modeled on an explicit raster level and exposure
data that are often available only for aggregated administrative units. Usually disaggregation methods that use ancillary
information to distribute lumped exposure data in a finer spatial resolution help to bridge this gap. However, the actual
influence of different mapping techniques and ancillary data on the final loss estimation has not been analyzed yet. In this
paper three methods are applied to disaggregate residential building assets using two kinds of land use/land cover (LULC)
data. The resulting disaggregated assets are validated and compared using census data of the residential building number on
the community and constituency level. In addition, the disaggregated assets are taken to estimate residential building losses
due to the flood in August 2002 in 21 municipalities on the River Mulde in Saxony, Germany. Losses are calculated with the
help of four loss models. In general, disaggregation helps to decrease the error variance within the loss estimation. It must,
however, be stated that the application of sophisticated disaggregation methods does not lead to significant improvements
compared to the straightforward binary method. Therefore more effort should instead be put into the provision of high-resolution
LULC data. Finally, the remaining uncertainties in loss estimation are high and demand further improvements in all modeling
aspects. 相似文献
750.