全文获取类型
收费全文 | 243篇 |
免费 | 3篇 |
专业分类
安全科学 | 9篇 |
废物处理 | 2篇 |
环保管理 | 28篇 |
综合类 | 114篇 |
基础理论 | 29篇 |
污染及防治 | 39篇 |
评价与监测 | 14篇 |
社会与环境 | 10篇 |
灾害及防治 | 1篇 |
出版年
2021年 | 3篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 3篇 |
2013年 | 13篇 |
2012年 | 6篇 |
2011年 | 7篇 |
2010年 | 5篇 |
2009年 | 9篇 |
2008年 | 7篇 |
2007年 | 6篇 |
2006年 | 6篇 |
2005年 | 8篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 4篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1994年 | 3篇 |
1993年 | 7篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 3篇 |
1985年 | 3篇 |
1983年 | 3篇 |
1977年 | 2篇 |
1976年 | 7篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1967年 | 4篇 |
1966年 | 3篇 |
1964年 | 4篇 |
1963年 | 4篇 |
1960年 | 3篇 |
1957年 | 2篇 |
1956年 | 3篇 |
1955年 | 2篇 |
1952年 | 3篇 |
1950年 | 5篇 |
1940年 | 2篇 |
1938年 | 2篇 |
1932年 | 3篇 |
1931年 | 2篇 |
1930年 | 4篇 |
1929年 | 2篇 |
1927年 | 2篇 |
1926年 | 2篇 |
1925年 | 2篇 |
排序方式: 共有246条查询结果,搜索用时 765 毫秒
241.
Trade-offs play pivotal roles in the ecology and evolution of natural populations. However, trade-offs are probably not static, invariant relationships. Instead, ecological factors can shift, alter, or reverse the relationships underlying trade-offs and create critical genotype x environment (G x E) interactions. But which ecological factors alter trade-offs or create G x E interactions, and why (mechanistically) do they do this? We tackle these questions using resource quality as the central ecological factor and a case study of disease in the plankton. We show that clonal genotypes of a zooplankton host (Daphnia dentifera) exhibit a "power-efficiency" trade-off in resource use, where powerful (fast-feeding) host clones perform well on richer algal resources, but more efficient (slow-feeding) clones perform relatively well on poorer resources. This resource-based trade-off then influences epidemiological relationships due to fundamental connections between resources and fecundity, transmission rate (an index of resistance), and replication of a virulent fungal parasite (Metschnikowia bicuspidata) within hosts. For instance, using experiments and dynamic energy budget models, we show that the power-efficiency trade-off overturned a previously detected trade-off between fecundity and transmission risk of hosts to this parasite. When poorer resources were eaten, transmission risk and fecundity were negatively, not positively, correlated. Additionally, poor resource quality changed positive relationships between yield of infectious stages (spores) and host fecundity: those fecundity-spore relationships with poor food became negative or nonsignificant. Finally, the power-efficiency trade-off set up an interaction between host clone and resource quality for yield of fungal spores: powerful clones yielded relatively more spores on the better resource, while efficient clones yielded relatively more on the poorer resource. Thus, the physiological ecology of resource use can offer potent, mechanistic insight linking environmental factors to epidemiological relationships. 相似文献
242.
243.
Leaching behaviour of wood treated with creosote 总被引:1,自引:0,他引:1
The results of a laboratory investigation on the leaching behaviour of wood treated with creosote and of untreated wood are reported. A special leaching test derived from the German standard method DEV S4 test (DIN 38414) has been developed. Samples were leached in deionized water, in a solution buffered at pH 4.7 and in a solution of humic substances. The organic fraction of the leachate was extracted using liquid-liquid extraction. The extracts were analysed qualitatively with GC/MSD and quantified with GC/FID. The results were compared with those of Soxhlet-extracts from creosote-treated wood. 相似文献
244.
Vander Pol SS Hobson KA Becker PR Day RD Ellisor MB Pugh RS Roseneau DG 《Journal of environmental monitoring : JEM》2011,13(3):699-705
The contents from thick-billed murre (Uria lomvia) eggs collected at four Alaskan colonies in 2002 were analyzed for organic contaminants and carbon δ13C) and nitrogen (δ1?N) stable isotopes. Contaminant concentrations in the eggs varied from below detection limits to 230 ng g?1 wet mass for 4,4'-DDE in one egg from St Lazaria Island in the Gulf of Alaska. Eggs from this colony generally contained higher levels of contaminants and exhibited significantly different patterns compared to eggs from the Bering and Chukchi seas. Stable isotope values also varied geographically; however, these differences appeared to be related to differences in C and N baselines in the food webs instead of differences in prey. Contaminant and stable isotope correlations were inconclusive, suggesting that better information on regional food web differences and differential offloading of contaminants and stable isotopes to the eggs must be obtained before these kinds of data can be fully incorporated into seabird egg contaminant monitoring programs. 相似文献
245.
Francis Turkelboom Rolinde Demeyer Liesbet Vranken Piet De Becker Filip Raymaekers Lieven De Smet 《Ambio》2021,50(8):1431
The strategy of reconnecting rivers with their floodplains currently gains popularity because it not only harnesses natural capacities of floodplains but also increases social co-benefits and biodiversity. In this paper, we present an example of a successfully implemented nature-based solution (NBS) in the Dijle valley in the centre of Belgium. The research objective is to retrospectively assess cost and benefit differences between a technical solution (storm basins) and an alternative NBS, here the restoration of the alluvial floodplain. The method is a comparative social cost–benefit analysis. The case study analysis reveals similar flood security, lower costs, more ecosystem services benefits and higher biodiversity values associated with the NBS option in comparison to the technical alternative. However, the business case for working with NBS depends substantially on the spatial and socio-ecological context. Chances for successful NBS implementation increase in conditions of sufficient space to retain flood water, when flood water is of sufficient quality, and when economic activity and housing in the floodplain is limited.Supplementary InformationThe online version of this article contains supplementary material available at (10.1007/s13280-021-01548-4). 相似文献
246.
Statistical control in correlational studies: 10 essential recommendations for organizational researchers
下载免费PDF全文
![点击此处可从《组织行为杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Thomas E. Becker Guclu Atinc James A. Breaugh Kevin D. Carlson Jeffrey R. Edwards Paul E. Spector 《组织行为杂志》2016,37(2):157-167
Statistical control is widely used in correlational studies with the intent of providing more accurate estimates of relationships among variables, more conservative tests of hypotheses, or ruling out alternative explanations for empirical findings. However, the use of control variables can produce uninterpretable parameter estimates, erroneous inferences, irreplicable results, and other barriers to scientific progress. As a result, methodologists have provided a great deal of advice regarding the use of statistical control, to the point that researchers might have difficulties sifting through and prioritizing the available suggestions. We integrate and condense this literature into a set of 10 essential recommendations that are generally applicable and which, if followed, would substantially enhance the quality of published organizational research. We provide explanations, qualifications, and examples following each recommendation. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献