全文获取类型
收费全文 | 320篇 |
免费 | 7篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 21篇 |
废物处理 | 6篇 |
环保管理 | 52篇 |
综合类 | 68篇 |
基础理论 | 35篇 |
污染及防治 | 110篇 |
评价与监测 | 18篇 |
社会与环境 | 10篇 |
灾害及防治 | 9篇 |
出版年
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2017年 | 13篇 |
2016年 | 7篇 |
2015年 | 6篇 |
2014年 | 8篇 |
2013年 | 39篇 |
2012年 | 11篇 |
2011年 | 18篇 |
2010年 | 10篇 |
2009年 | 5篇 |
2008年 | 21篇 |
2007年 | 17篇 |
2006年 | 17篇 |
2005年 | 21篇 |
2004年 | 14篇 |
2003年 | 13篇 |
2002年 | 14篇 |
2001年 | 4篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 7篇 |
1996年 | 1篇 |
1995年 | 4篇 |
1994年 | 6篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 6篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1982年 | 2篇 |
1979年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1969年 | 1篇 |
1964年 | 5篇 |
1963年 | 1篇 |
1962年 | 2篇 |
1961年 | 2篇 |
1960年 | 1篇 |
排序方式: 共有329条查询结果,搜索用时 15 毫秒
311.
312.
313.
314.
315.
316.
Ilg C Dziock F Foeckler F Follner K Gerisch M Glaeser J Rink A Schanowski A Scholz M Deichner O Henle K 《Ecology》2008,89(9):2392-2398
Extreme summertime flood events are expected to become more frequent in European rivers due to climate change. In temperate areas, where winter floods are common, extreme floods occurring in summer, a period of high physiological activity, may seriously impact floodplain ecosystems. Here we report on the effects of the 2002 extreme summer flood on flora and fauna of the riverine grasslands of the Middle Elbe (Germany), comparing pre- and post-flooding data collected by identical methods. Plants, mollusks, and carabid beetles differed considerably in their response in terms of abundance and diversity. Plants and mollusks, displaying morphological and behavioral adaptations to flooding, showed higher survival rates than the carabid beetles, the adaptation strategies of which were mainly linked to life history. Our results illustrate the complexity of responses of floodplain organisms to extreme flood events. They demonstrate that the efficiency of resistance and resilience strategies is widely dependent on the mode of adaptation. 相似文献
317.
Although evidence is accumulating on the adaptive function of female ornamentation, very little is known about maternal allocation
decisions involving sexual signaling and other reproductive functions. Blue egg coloration has been suggested as a sexually
selected signal of female quality to males, and some recent studies are in accordance with this hypothesis. Blue eggshell
coloration results from the deposition of biliverdin pigment by laying females, which is a potent antioxidant. Thus, egg pigmentation
should be costly in terms of antioxidants, an assumption of the signaling hypothesis that has not been tested yet. We induced
increased reproductive effort in a set of female pied flycatchers Ficedula hypoleuca through nest removal and measured egg pigmentation and plasma antioxidant levels in relation with a control group. Experimental
females showed a negative association between egg color and plasma antioxidant levels, while there was no relationship for
control birds. This supports that egg pigmentation is costly in terms of general antioxidant defenses and suggests a tradeoff
between the allocations to both traits. Furthermore, experimental females with more colorful eggs raised more fledglings,
especially when breeding early. Controls did not show a relationship between egg color and reproductive success. Females laying
more colorful eggs could have shifted their allocation decisions towards current reproduction, at the expense of their own
antioxidant defenses. Our results highlight that blue egg coloration is a life-history trait, subject to tradeoffs with other
attributes, and seems to be especially informative under harsh breeding conditions. 相似文献
318.
Previous time-series studies of meroplankton abundances in the LEO-15 research area off Tuckerton, New Jersey, USA (39°28′N, 74°15′W) indicated short-lived (6–12 h) pulses in larval surfclam (Spisula solidissima Dillwyn) concentration often associated with the initiation of downwelling. To examine possible larval surfclam (and other bivalve) concentrating mechanisms during upwelling and downwelling, six sets of adaptive mobile zooplankton pump samples were taken in July 1998 at different depths at five to six stations along a 25-km transect perpendicular to the coastline and crossing Beach Haven Ridge at LEO-15. Sampling was guided by near real-time, satellite imagery of sea surface temperature overlain by sea surface currents from a shore-based ocean surface current radar (OSCR) unit. A Seabird CTD on the mobile pump frame near the intake provided information on thermocline depth, and sampling depths were adjusted according to the temperature profiles. Near shore, the thermocline was tilted down during downwelling, and up during upwelling. The highest concentrations of surfclam larvae occurred near the bottom at a station near Beach Haven Ridge during downwelling, and just above the thermocline 3 km further offshore during well-developed upwelling. For other bivalve taxa, the larvae were concentrated near the thermocline (Anomia simplex Orbigny and Pholadidae spp.) or concentrated upslope near the bottom (Mytilidae spp.) during upwelling, and the larvae were concentrated near the bottom or were moved downslope during downwelling. Donax fossor Say larvae were found near the surface or above the thermocline during upwelling and downwelling. The general patterns of larval bivalve distribution appear to be influenced by water mass movement during upwelling and downwelling. The larval concentration patterns of individual species are likely a consequence of advection due to upwelling and downwelling circulation, vertical shear in the front region, species-specific larval behaviors, and larval sources. 相似文献
319.
Water samples were collected between 1999 and 2000 from wetlands in Minnesota that contained malformed frogs. The water samples were analyzed for 14 minerals/ions and screened for the presence of biologically active compounds using Xenopus laevis. Results indicated that water from two sites, CWB and ROI2, induced severe retardation with embryo lengths reduced 20% after 96 hr of development. The developmental delay observed with water from ROI2 was alleviated by supplementation with sodium, while both sodium and potassium alleviated the developmental delay observed with water whose mineral content mimicked that of CWB. Seasonal fluctuations in the sodium and potassium content at ROI2 and NEY correlated with changes in the rates of Xenopus development. Xenopus embryos reared on water from ROI2 for 120 hr displayed gut malformations not present in embryos reared on a synthetic media designed to mimic the mineral content of the water from ROI2. Embryos reared on water from ROI2 supplemented with minerals at levels comparable to that routinely employed in the rearing of Xenopus were neither retarded nor malformed. It is proposed that climate driven hydrology may influence the mineral composition at selected wetlands and delay development which may alter window(s) of susceptibility towards biologically active agents and the occurrence of malformed frogs. 相似文献
320.
Judith Petts 《Journal of Environmental Planning and Management》1995,38(4):519-536
Public opposition to the siting of waste facilities has been partly explained by a failure to directly involve communities in fundamental policy decisions about waste management. Public participation at the local level is primarily reactive, based upon the premise of consultation on preferred strategies rather than direct involvement in their derivation. This paper presents the findings of a study into the effectiveness of a more proactive community involvement programme adopted by one English county council. The paper suggests some opportunities and barriers to public involvement in waste management strategy development and the potential effectiveness of consensus-building approaches. 相似文献