全文获取类型
收费全文 | 516篇 |
免费 | 10篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 28篇 |
废物处理 | 26篇 |
环保管理 | 66篇 |
综合类 | 45篇 |
基础理论 | 125篇 |
污染及防治 | 161篇 |
评价与监测 | 39篇 |
社会与环境 | 30篇 |
灾害及防治 | 10篇 |
出版年
2023年 | 6篇 |
2022年 | 10篇 |
2021年 | 10篇 |
2020年 | 8篇 |
2019年 | 10篇 |
2018年 | 12篇 |
2017年 | 13篇 |
2016年 | 17篇 |
2015年 | 15篇 |
2014年 | 16篇 |
2013年 | 47篇 |
2012年 | 25篇 |
2011年 | 43篇 |
2010年 | 29篇 |
2009年 | 30篇 |
2008年 | 28篇 |
2007年 | 33篇 |
2006年 | 34篇 |
2005年 | 33篇 |
2004年 | 19篇 |
2003年 | 14篇 |
2002年 | 17篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 6篇 |
1998年 | 4篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1974年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有530条查询结果,搜索用时 31 毫秒
471.
Emily B. Dennis Byron J.T. Morgan Tom M. Brereton David B. Roy Richard Fox 《Conservation biology》2017,31(6):1350-1361
Citizen scientists are increasingly engaged in gathering biodiversity information, but trade‐offs are often required between public engagement goals and reliable data collection. We compared population estimates for 18 widespread butterfly species derived from the first 4 years (2011–2014) of a short‐duration citizen science project (Big Butterfly Count [BBC]) with those from long‐running, standardized monitoring data collected by experienced observers (U.K. Butterfly Monitoring Scheme [UKBMS]). BBC data are gathered during an annual 3‐week period, whereas UKBMS sampling takes place over 6 months each year. An initial comparison with UKBMS data restricted to the 3‐week BBC period revealed that species population changes were significantly correlated between the 2 sources. The short‐duration sampling season rendered BBC counts susceptible to bias caused by interannual phenological variation in the timing of species’ flight periods. The BBC counts were positively related to butterfly phenology and sampling effort. Annual estimates of species abundance and population trends predicted from models including BBC data and weather covariates as a proxy for phenology correlated significantly with those derived from UKBMS data. Overall, citizen science data obtained using a simple sampling protocol produced comparable estimates of butterfly species abundance to data collected through standardized monitoring methods. Although caution is urged in extrapolating from this U.K. study of a small number of common, conspicuous insects, we found that mass‐participation citizen science can simultaneously contribute to public engagement and biodiversity monitoring. Mass‐participation citizen science is not an adequate replacement for standardized biodiversity monitoring but may extend and complement it (e.g., through sampling different land‐use types), as well as serving to reconnect an increasingly urban human population with nature. 相似文献
472.
Schoffer Jorge Tomás Antilén Mónica Neaman Alexander Díaz María Francisca de la Fuente Luz María Urdiales Cristian Ginocchio Rosanna 《Environmental science and pollution research international》2021,28(43):60913-60922
Environmental Science and Pollution Research - This study assessed the capacity of leaf litters to adsorb copper ions applied as a copper-based pesticide. Leaf litters of two fruit tree species... 相似文献
473.
Luis?Tomás?Montilla FernándezEmail author Johannes?Schwarze 《Journal of Agricultural and Environmental Ethics》2013,26(6):1223-1240
During the 2007–2008 global food crisis, the prices of primary foods, in particular, peaked. Subsequently, governments concerned about food security and investors keen to capitalize on profit-maximizing opportunities undertook large-scale land acquisitions (LASLA) in, predominantly, least developed countries (LDCs). Economically speaking, this market reaction is highly welcome, as it should (1) improve food security and lower prices through more efficient food production while (2) host countries benefit from development opportunities. However, our assessment of the debate on the issues indicates critical voices in both the media and academic discourse. This article aims to provide a philosophical law and economics analysis. We draw on John Rawls’s Theory of Justice, focusing on Rawls’s background institutions for distributive justice (§43) to evaluate LASLA form an ethical angle. Approaching LASLA into Sub Saharan LDCs as a socio-economic reform redistributing land from the local population of LDCs to investors, we acknowledge that they bear a highly desirable potential. Often, though, they cannot be regarded as ethically correct in practice as the insignificant improvements for local populations and sometimes even human rights violations contradict Rawls’s principles of justice. Then investigating whether and how international law can help overcome the shortcomings, we conclude that even though respective mechanisms exist in the current state of international law, it is hardly possible that it will produce more just outcomes in the near future. 相似文献
474.
Fabio Ferrero Ronald Meyer Martin Kluge Volkmar Schröder Tom Spoormaker 《Journal of Loss Prevention in the Process Industries》2013,26(4):759-765
The Ignition Temperature (IT) of stoichiometric tetrafluoroethylene–air mixtures on hot walls was determined in a 3-dm³-reactor. Tests at elevated pressure conditions were performed, namely at 5, 15 and 25 bar(a), showing a decrease of the IT with the initial pressure. Furthermore, the measured ignition temperatures of stoichiometric tetrafluoroethylene–air mixtures were lower than the ignition temperatures required for the decomposition pure tetrafluoroethylene (Minimum Ignition Temperature of Decomposition, MITD) reported in previous works.Equations from the Semenov thermal explosion theory on spontaneous ignition were used to identify approximate combustion kinetics of tetrafluoroethylene from the experimental results. The determined kinetics was used for the prediction of the IT of stoichiometric tetrafluoroethylene-air by simplified calculation methods. A very good agreement with the experimental results was observed. 相似文献
475.
Jean Hugé Tom Waas Farid Dahdouh-Guebas Nico Koedam Thomas Block 《Sustainability Science》2013,8(2):187-198
Sustainable development is a ubiquitously used concept in public decision-making: it refers to an ideal vision of global society where human development and environmental quality go hand in hand. Logically, any decision-supporting process aiming at facilitating and steering society toward a sustainable future then seems desirable. Assessing the sustainability of policy decisions is, however, influenced by what sustainable development is believed to entail, as different discourses coexist under the umbrella of the sustainable development meta-discourse. This paper proposes a typology of sustainable development discourses, and, subsequently, applies a discourse-analytical lens on two practical cases of sustainability assessment in different institutional and geographical contexts (in Belgium and in Benin). The results indicate that sustainability assessments tend to be influenced mainly by the consensual ‘sustainable development as integration’ discourse, while also providing a forum for dialogue between different discourses. The results shed light on context-specific discursive and institutional dynamics for the development and application of sustainability assessment. Acknowledging these dynamics as well as sustainable development’s inherent interpretational limits can lead to an improved use of sustainable development as a decision-guiding strategy. 相似文献
476.
477.
Offspring sex ratio in relation to female size in southern elephant seals,Mirounga leonina 总被引:1,自引:0,他引:1
Southern elephant seals Mirounga leonina display extreme sexual dimorphism. In addition females show great variation in size and stored resources at parturition. Therefore they present an excellent opportunity for examination of responses of sex ratio to resource availability. We studied the relationships between the size of southern elephant seal females at parturition and the size and sex of their pups at South Georgia over four breeding seasons. We found a large individual variation in maternal post-partum mass (range 296–977 kg, n=151). Larger mothers gave birth to larger pups, irrespective of the sex of their pup. Male pups were on average 14% larger than females at birth and consequently more costly to bring to parturition. Our results suggest that female southern elephant seals must weigh more than 300 kg if they are to breed at all, and more than 380 kg if they are to give birth to a male pup. Above this threshold the proportion of males among offspring rapidly increases with maternal mass, and stabilizes at a level not significantly different from parity. These results show that smaller females of southern elephant seals vary offspring sex ratio in a way that is consistent with theories on adaptive offspring sex ratio. A smaller mother with a male foetus may benefit from terminating her pregnancy and allocating the resources she saves to her own growth. She could then give birth to and raise a larger pup in the subsequent season. 相似文献
478.
Clive?BonsallEmail author Adina?Boronean? Andrei?Soficaru Kathleen?McSweeney Tom?Higham Nicolae?Miri?oiu Catriona?Pickard Gordon?Cook 《Die Naturwissenschaften》2012,99(4):321-325
In 1968, excavations in the Climente II cave in the Iron Gates gorge of the River Danube in southwest Romania unearthed the skeleton of an adult male. The burial was assumed to be of Late Pleistocene age because of the presence of Late Upper Palaeolithic (LUP) artefacts in the cave. However, there was no strong supporting stratigraphic evidence, and the body position is reminiscent of Early Neolithic burial practice in the region. Here, we report the results of radiocarbon and stable isotope analyses of the Climente II skeleton, which show that the skeleton dates to the Bølling–Allerød Interstadial ~14,500 cal BP. This is several millennia older than any previously dated human remains from the Iron Gates region and confirms its status as the oldest known burial from Romania. The stable isotope results indicate a diet with an emphasis on aquatic resources, contrary to the commonly held view that the LUP inhabitants of the Iron Gates subsisted mainly by hunting large land mammals. 相似文献
479.
The trophic importance of bacteria to harpacticoid copepods in intertidal areas remains poorly understood, and so do the mechanisms of bacterial feeding. It is, for instance, unclear whether harpacticoids directly target bacterial cells or merely co-ingest them with substrates to which bacterial cells may be attached. Here, we investigate bacterial uptake and substrate requirement for four mud intertidal species (Microarthridion littorale, Platychelipus littoralis, Delavalia palustris and Nannopus palustris) by means of 13C-labeled bacteria and biomarker fatty acids (FA). Bacterial uptake strongly depended on grazing on a primary food source but bacterial ingestion rates were low, and no clear indication of copepods directly targeting bacteria was found. Delavalia was the only species that accumulated bacteria-derived FA and gained in polyunsaturated FA (PUFA) probably through bioconversion of bacteria-derived FA. In general, however, our results suggest that bacteria represent a relatively minor and low-quality food for intertidal harpacticoid copepods. 相似文献
480.
Joshua Farley David Batker Isabel de la Torre Tom Hudspeth 《Environmental management》2010,45(1):39-51
Humans are rapidly depleting critical ecosystems and the life support functions they provide, increasing the urgency of developing
effective conservation tools. Using a case study of the conversion of mangrove ecosystems to shrimp aquaculture, this article
describes an effort to develop a transdisciplinary, transinstitutional approach to conservation that simultaneously trains
future generations of environmental problem solvers. We worked in close collaboration with academics, non-government organizations,
local government and local communities to organize a workshop in Puerto Princesa, Palawan, Philippines. The primary objectives
of the workshop were to: (1) train participants in the basic principles of ecological economics and its goals of sustainable
scale, just distribution and efficient allocation; (2) learn from local community stakeholders and participating scientists
about the problems surrounding conversion of mangrove ecosystems to shrimp aquaculture; (3) draw on the skills and knowledge
of all participants to develop potential solutions to the problem; and (4) communicate results to those with the power and
authority to act on them. We found that the economic and ecological benefits of intact mangroves outweigh the returns to aquaculture.
Perversely, however, private property rights to mangrove ecosystems favor inefficient, unjust and unsustainable allocation
of the resource—a tragedy of the non-commons. We presented the workshop results to the press and local government, which shut
down the aquaculture ponds to conserve the threatened ecosystem. Effective communication to appropriate audiences was essential
for transforming research into action. Our approach is promising and can be readily applied to conservation research and advocacy
projects worldwide, but should be improved through adaptive management—practitioners must continually build on those elements
that work and discard or improve those that fail. 相似文献