全文获取类型
收费全文 | 639篇 |
免费 | 8篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 22篇 |
废物处理 | 18篇 |
环保管理 | 85篇 |
综合类 | 93篇 |
基础理论 | 147篇 |
环境理论 | 2篇 |
污染及防治 | 190篇 |
评价与监测 | 40篇 |
社会与环境 | 46篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 2篇 |
2022年 | 8篇 |
2021年 | 13篇 |
2020年 | 4篇 |
2019年 | 8篇 |
2018年 | 21篇 |
2017年 | 17篇 |
2016年 | 18篇 |
2015年 | 27篇 |
2014年 | 29篇 |
2013年 | 48篇 |
2012年 | 26篇 |
2011年 | 38篇 |
2010年 | 45篇 |
2009年 | 38篇 |
2008年 | 31篇 |
2007年 | 37篇 |
2006年 | 32篇 |
2005年 | 20篇 |
2004年 | 28篇 |
2003年 | 21篇 |
2002年 | 27篇 |
2001年 | 10篇 |
2000年 | 17篇 |
1999年 | 16篇 |
1998年 | 7篇 |
1997年 | 7篇 |
1996年 | 4篇 |
1995年 | 7篇 |
1994年 | 10篇 |
1993年 | 3篇 |
1991年 | 2篇 |
1989年 | 2篇 |
1984年 | 2篇 |
1980年 | 3篇 |
1976年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1964年 | 1篇 |
1963年 | 1篇 |
1962年 | 1篇 |
1961年 | 1篇 |
1958年 | 1篇 |
1955年 | 1篇 |
1949年 | 1篇 |
1948年 | 1篇 |
1937年 | 1篇 |
1920年 | 1篇 |
排序方式: 共有649条查询结果,搜索用时 250 毫秒
361.
Lindström ES Eiler A Langenheder S Bertilsson S Drakare S Ragnarsson H Tranvik LJ 《Ecology》2007,88(1):252-3; discussion 253-5
362.
Lauge Peter Westergaard Clausen Stefan Trapp 《Environmental science and pollution research international》2017,24(22):18035-18047
Toxicity data of substances to higher plants is needed for the purpose of risk assessment, site evaluation, phytoremediation, and plant protection. However, the results from the most common phytotoxicity tests, like the OECD algae and Lemna test, are not necessarily valid for higher terrestrial plants. The willow tree toxicity test uses inhibition of transpiration (aside of growth and water use efficiency) of willow cuttings grown in spiked solutions or soils as end point to quantify toxicity. This overview presents results from 60 studies including 24 new unpublished experiments for 56 different chemicals or substrates. Highest toxicity (EC50 < 1 mg/L) was observed from exposure to heavy metals like copper and cadmium. Also, organotins and free cyanide showed very high toxicity. The toxic effect of chlorophenols on willows was comparable to that on duck weed (Lemna) and green algae, while volatile compounds like chlorinated solvents or benzene, toluene, ethylbenzene, and xylene had less effect on trees than on these aquatic plants, due to volatilization from leaves and test media. In particular low (g/L range) toxicity was observed for tested nanomaterials. Effects of pharmaceuticals (typically weak acids or bases) depended strongly of the solution pH. Like for algae, baseline toxicity was observed for willows, which is related to the water solubility of the compounds, with absolute chemical activity ranging from 0.01 to 0.1, but with several exceptions. We conclude that the willow tree toxicity test is a robust method for relating uptake, accumulation, and metabolism of substances to the toxicity to trees. 相似文献
363.
MC Cruz DG Cacciabue JF Gil O Gamboni MS Vicente S Wuertz E Gonzo VB Rajal 《Journal of environmental monitoring : JEM》2012,14(9):2338-2349
Many developing and threshold countries rely on shallow groundwater wells for their water supply whilst pit latrines are used for sanitation. We employed a unified strategy involving satellite images and environmental monitoring of 16 physico-chemical and microbiological water quality parameters to identify significant land uses that can lead to unacceptable deterioration of source water, in a region with a subtropical climate and seasonally restricted torrential rainfall in Northern Argentina. Agricultural and non-agricultural sources of nitrate were illustrated in satellite images and used to assess the organic load discharged. The estimated human organic load per year was 28.5 BOD(5) tons and the N load was 7.5 tons, while for poultry farms it was 9940-BOD(5) tons and 1037-N tons, respectively. Concentrations of nitrates and organics were significantly different between seasons in well water (p values of 0.026 and 0.039, respectively). The onset of the wet season had an extraordinarily negative impact on well water due in part to the high permeability of soils made up of fine gravels and coarse sand. Discriminant analysis showed that land uses had a pronounced seasonal influence on nitrates and introduced additional microbial contamination, causing nitrification and denitrification in shallow groundwater. P-well was highly impacted by a poultry farm while S-well was affected by anthropogenic pollution and background load, as revealed by Principal Component Analysis. The application of microbial source tracking techniques is recommended to corroborate local sources of human versus animal origin. 相似文献
364.
Stefan?MayerEmail author Magdalena?Twaru?ek Anna?B?ajet-Kosicka Jan?Grajewski 《Environmental monitoring and assessment》2016,188(3):154
Manual sorting of onions is known to be associated with a bioaerosol exposure. The study aimed to gain an initial indication as to what extent manual sorting of onions is also associated with mycotoxin exposure. Twelve representative samples of outer onion skins from different onion origins were sampled and analyzed with a multimycotoxin method comprising 40 mycotoxins using a single extraction step followed by liquid chromatography with electrospray ionization and triple quadrupole mass spectrometry. Six of the 12 samples were positive for mycotoxins. In those samples, deoxynivalenol, fumonisin B1, and B2 were observed in quantitatively detectable amounts of 3940 ng/g for fumonisin B1 and in the range of 126–587 ng/g for deoxynivalenol and 55–554 ng/g for fumonisin B2. Although the results point to a lower risk due to mycotoxins, the risk should not be completely neglected and has to be considered in the risk assessment. 相似文献
365.
Stefan H. Nessler Gabriele Uhl Jutta M. Schneider 《Behavioral ecology and sociobiology》2009,63(3):355-362
Sperm competition is a potent driving force in evolution leading to a remarkable variety of male adaptations that prevent
or reduce fertilization by rivals. An extraordinary defensive strategy against sperm competition has evolved in a number of
web spiders where males break off parts of their paired genitalia in order to obstruct the copulatory openings of females
(mating plug). A recent comparative analysis on the family level reports that genital damage is most frequent in species with
sexual cannibalism although, as yet, a functional association between sexual cannibalism and genital damage has not been found.
Using the moderately sexually cannibalistic orb-web spider Argiope lobata, we show for the first time that males cannibalized during their first copulation damaged their pedipalps with significantly
higher probability (74%) than males that escaped (15%). Of all males that damaged their genitalia, 44% were able to place
a genital fragment inside the copulatory opening of the female, resulting in a relatively low total plugging rate of 14%.
Successful obstruction of the female copulatory opening reduced the share of paternity of subsequent males (P
2 = 0.06%), thus, indicating that genital damage may have evolved as a response to sperm competition in this species as well.
However, the low incidence of successful plugging and the strong relationship between sexual cannibalism and genital damage
suggest that apart from paternity protection, the nature of genital damage in A. lobata is further shaped by sexual conflict or cryptic female choice. 相似文献
366.
Peter Miehle Michael Battaglia Peter J. Sands David I. Forrester Paul M. Feikema Stephen J. Livesley Jim D. Morris Stefan K. Arndt 《Ecological modelling》2009
In forest management and ecological research, consideration of the impacts and risks of climate change or management optimisation is complex. Computer models have long been applied as tools for these tasks. Process-based forest growth models claim to overcome the limitations of empirical statistical models, but the capacity of different process-based models and modelling approaches have rarely been compared directly. This study evaluates stepwise multiple regression models in comparison to four process-based modelling approaches (3-PG, 3-PG+, CABALA and Forest-DNDC) for greenfield predictions of Eucalyptus globulus plantation growth from 2 to 8 years after planting throughout southern Australia. 相似文献
367.
Energy dissipation, flow resistance and gas-liquid interfacial area in skimming flows on moderate-slope stepped spillways 总被引:2,自引:2,他引:0
With the re-evaluation and revision of a number of design floods, several embankment overtopping protection systems have been
developed and a common technique is the construction of a stepped spillway on the downstream slope. For such moderate slope
stepped channels, detailed air–water flow measurements were performed in a large facility with a focus on the rate of energy
dissipation, flow resistance, air–water interfacial areas and re-aeration rates. Past and present experimental results showed
a significant aeration of the flow. The median dimensionless residual head was about 3 × dc for the 21.8° sloping chute and smaller than that for flatter slopes (θ = 3.4° and 15.9°). The flow resistance results yielded an equivalent Darcy friction factor of about 0.25 implying a larger
flow resistance for the 21.8° slope angle than for smaller slope angles. The re-aeration rate was deduced from the integration
of the mass transfer equation using measured air–water interfacial areas and air–water flow velocities. The results suggested
an increasing re-aeration rate with increasing rate of energy dissipation. The stepped invert contributed to intense turbulence
production, free-surface aeration and large interfacial areas. The experimental data showed however some distinctive seesaw
pattern in the longitudinal distribution of air–water flow properties with a wave length of about two step cavities. While
these may be caused by the interactions between successive adjacent step cavities and their interference with the free-surface,
the existence of such “instabilities” implies that the traditional concept of normal flow might not exist in skimming flows
above moderate-slope stepped spillways. 相似文献
368.
Rajalakshmi M. Josiam Heinz G. Stefan 《Journal of the American Water Resources Association》1999,35(2):433-439
ABSTRACT: Theoretical equations that establish the relationship between sediment oxygen demand (SOD) in a lake and the flow velocity and dissolved oxygen concentration in the bulk water already exist. These theoretical equations for oxygen consumption in the sediment express biological consumption with Michaelis-Menten kinetics, and chemical consumption by a first order reaction. Data from laboratory experiments that were conducted to validate the theoretical equations also exist. These experiments were performed in a laboratory channel with well defined flow characteristics for three types of sediments. Herein, the theoretical equations are used to model the experimental data for the three types of sediments. The values used for the parameters in the theoretical equations are determined by iteration until a best fit is obtained for the relationship of SOD to flow velocity from both the theoretical model and experimental data. The goodness of fit is measured by the standard error of prediction and the regression coefficient. 相似文献
369.
Ohne Zusammenfassung
The online version of the original article can be found at 相似文献
370.