全文获取类型
收费全文 | 1055篇 |
免费 | 27篇 |
国内免费 | 10篇 |
专业分类
安全科学 | 28篇 |
废物处理 | 31篇 |
环保管理 | 238篇 |
综合类 | 175篇 |
基础理论 | 227篇 |
环境理论 | 1篇 |
污染及防治 | 281篇 |
评价与监测 | 58篇 |
社会与环境 | 43篇 |
灾害及防治 | 10篇 |
出版年
2023年 | 20篇 |
2022年 | 14篇 |
2021年 | 22篇 |
2020年 | 20篇 |
2019年 | 13篇 |
2018年 | 23篇 |
2017年 | 29篇 |
2016年 | 32篇 |
2015年 | 44篇 |
2014年 | 36篇 |
2013年 | 107篇 |
2012年 | 35篇 |
2011年 | 61篇 |
2010年 | 44篇 |
2009年 | 53篇 |
2008年 | 57篇 |
2007年 | 54篇 |
2006年 | 54篇 |
2005年 | 43篇 |
2004年 | 42篇 |
2003年 | 33篇 |
2002年 | 35篇 |
2001年 | 15篇 |
2000年 | 16篇 |
1999年 | 20篇 |
1998年 | 12篇 |
1997年 | 12篇 |
1996年 | 12篇 |
1995年 | 10篇 |
1994年 | 13篇 |
1993年 | 14篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 9篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1985年 | 15篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有1092条查询结果,搜索用时 15 毫秒
171.
Philip Chao 《Journal of the American Water Resources Association》1999,35(6):1499-1507
ABSTRACT: The U.S. Army Corps of Engineers conducted an assessment of Great Lakes water resources impacts under transient climate change scenarios. The integrated model linked empirical regional climate downscaling, hydrologic and hydraulic models, and water resource use sub-models. The water resource uses include hydropower, navigation, shoreline damages, and wetland area. The study is unique in that both steady-state 2°CO2 and transient global circulation model (GCM) scenarios were used and compared to each other. The results are consistent with other impact studies in that high scatter in regional climate among the GCM scenarios lead to high uncertainty in impacts. Nevertheless, the transient scenarios show that in the near-term (approximately 20 years) significant changes could occur. This result only adds to the urgency of creating more flexible and robust management of water resources uses. 相似文献
172.
173.
Lucas Ferrante Augusto Getirana Fabricio Beggiato Baccaro Jochen Schöngart Ana Cristina Monteiro Leonel Renato Gaiga Michel Varajão Garey Philip Martin Fearnside 《Conservation biology》2023,37(3):e14033
Given the speed at which humans are changing the climate, species with high degrees of endemism may not have time to avoid extinction through adaptation. We investigated through teleconnection analysis the origin of rainfall that determines the phylogenetic diversity of rainforest frogs and the effects of microclimate differences in shaping the morphological traits of isolated populations (which contribute to greater phylogenetic diversity and speciation). We also investigated through teleconnection analysis how deforestation in Amazonia can affect ecosystem services that are fundamental to maintaining the climate of the Atlantic rainforest biodiversity hotspot. Seasonal winds known as flying rivers carry water vapor from Amazonia to the Atlantic Forest, and the breaking of this ecosystem service could lead Atlantic Forest species to population decline and extinction in the short term. Our results suggest that the selection of morphological traits that shape Atlantic Forest frog diversity and their population dynamics are influenced by the Amazonian flying rivers. Our results also suggest that the increases of temperature anomalies in the Atlantic Ocean due to global warming and in the Amazon forest due to deforestation are already breaking this cycle and threaten the biodiversity of the Atlantic Forest hotspot. 相似文献
174.
The Pygmalion effect, a type of self‐fulfilling prophecy, has been demonstrated in educational settings with empirical studies, qualitative reviews and meta‐analyses. It has also been studied in organizational settings. This meta‐analysis provides a review of the Pygmalion literature, an analysis of findings to date, and a deeper look into the nature of the effect. The present analysis of 13 effect sizes revealed an overall d for the Pygmalion effect in work organizations of 0.81. Moderator analyses revealed stronger effects when the initial level of performance was low and when the experiment took place in a military rather than a business setting. Implications of these findings are discussed. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
175.
Tang Xiaochun Lin Pengzhi Liu Philip L.-F. Zhang Xiaofeng 《Environmental Fluid Mechanics》2021,21(5):1137-1163
Environmental Fluid Mechanics - A numerical model based on the double-averaged (spatial and ensemble averaged) method has been developed to simulate vegetated free surface flows. The classical $$k... 相似文献
176.
Zia?RehmanEmail author Christina?Nicole?Toms Craig?Finch 《Environmental and Ecological Statistics》2016,23(4):623-638
We present a novel, non-parametric, frequentist approach for capture-recapture data based on a ratio estimator, which offers several advantages. First, as a non-parametric model, it does not require a known underlying distribution for parameters nor the associated assumptions, eliminating the need for post-hoc corrections or additional modeling to account for heterogeneity and other violated assumptions. Second, the model explicitly deals with dependence of trials by considering trials to be dependent; therefore, cluster sampling is handled naturally and additional adjustments are not necessary. Third, it accounts for ordering, utilizing the fact that a system with a small population will have a greater frequency of recaptures “early” in the survey work compared to an identical system with a larger population. We provide mathematical proof that our estimator attains asymptotic minimum variance under open systems. We apply the model to a data set of bottlenose dolphins (Tursiops truncatus) and compare results to those from classic closed models. We show that the model has an impressive rate of convergence and demonstrate that there’s an inverse relationship between population size and the proportion of the population that need to be sampled, while achieving the same degree of accuracy for abundance estimates. The model is flexible and can apply to ecological situations as well as other situations that lend themselves to capture recapture sampling. 相似文献
177.
The invasive non-native shrub Rosa rugosa (Japanese Rose) is well-established in many northwest European countries where, especially on coastal sand-dunes, it forms large dominant stands with adverse effects on semi-natural vegetation and biota of high conservation status. Its recent increase in England’s largest dune system on the Sefton Coast in north Merseyside led to an investigation into its rate of spread. Using digitised aerial photographs and GIS methodology, sample patches of old-established R. rugosa were found to have grown in area by an average of 22 % per annum between 1989 and 2013. This rate of increase is comparable to that found in Denmark and higher than reported for several other woody plants in coastal dunes. In the absence of management, R. rugosa could soon dominate large areas on the Sefton Coast, with serious consequences for amenity and the nature conservation interest of the dune system. 相似文献
178.
Mary Beth LEIGH Wei-Min WU Erick CARDENAS Ondrej UHLIK Sue CARROLL Terry GENTRY Terence L. MARSH Jizhong ZHOU Philip JARDINE Craig S. CRIDDLE James M. TIEDJE 《Frontiers of Environmental Science & Engineering》2015,9(3):453
Stable isotope probing (SIP) was used to identify microbes stimulated by ethanol addition in microcosms containing two sediments collected from the bioremediation test zone at the US Department of Energy Oak Ridge site, TN, USA. One sample was highly bioreduced with ethanol while another was less reduced. Microcosms with the respective sediments were amended with 13C labeled ethanol and incubated for 7 days for SIP. Ethanol was rapidly converted to acetate within 24 h accompanied with the reduction of nitrate and sulfate. The accumulation of acetate persisted beyond the 7 d period. Aqueous U did not decline in the microcosm with the reduced sediment due to desorption of U but continuously declined in the less reduced sample. Microbial growth and concomitant 13C-DNA production was detected when ethanol was exhausted and abundant acetate had accumulated in both microcosms. This coincided with U(VI) reduction in the less reduced sample. 13C originating from ethanol was ultimately utilized for growth, either directly or indirectly, by the dominant microbial community members within 7 days of incubation. The microbial community was comprised predominantly of known denitrifiers, sulfate-reducing bacteria and iron (III) reducing bacteria including Desulfovibrio, Sphingomonas, Ferribacterium, Rhodanobacter, Geothrix, Thiobacillus and others, including the known U(VI)-reducing bacteria Acidovorax, Anaeromyxobacter, Desulfovibrio, Geobacter and Desulfosporosinus. The findings suggest that ethanol biostimulates the U(VI)-reducing microbial community by first serving as an electron donor for nitrate, sulfate, iron (III) and U(VI) reduction, and acetate which then functions as electron donor for U(VI) reduction and carbon source for microbial growth. 相似文献
179.
Eric Vander Wal Michel P. Laforge Philip D. McLoughlin 《Behavioral ecology and sociobiology》2014,68(3):383-390
Sociality is poorly understood in the context of population processes. We used wild, female elk (Cervus canadensis) equipped with proximity-logging radio collars (n?=?62) from Manitoba, Canada (2007–2009), to test for modifying effects of population density (two areas: 0.42 and 0.22 animals/km2) on the relationship between two measures of sociality. This included the rate at which collared individuals encountered one another per year (encounters logged as animals ranging to within 1.4 m of each other) and the extent to which animals overlapped in annual home range (proportion of shared minimum convex polygon ranges). Overlap was significantly greater in the high density area compared to that of the low, but not if we only considered individuals that directly encountered each other, implying that familiar individuals will maintain a constant degree of range overlap regardless of density. Encounter rate was nonlinearly related to home range overlap. This relationship was also density-dependent, exhibiting negative density dependence at high proportions of overlap, primarily in the high density subpopulation. Sociality, as defined by two interacting measures of behaviour—encounter rate and home range overlap—exhibits a complex nonlinear relationship; we discuss the implications of these results as they pertain to sociobiology, resource competition, and pathogen transmission. 相似文献
180.
The environmental impact of nanotechnology has caused a great concern. Many in vitro studies showed that many types of nanoparticles were cytotoxic. However, whether these nanoparticles caused cell membrane damage was not well studied. F2-isoprostanes are specific products of arachidonic acid peroxidation by nonenzymatic reactive oxygen species and are considered as reliable biomarkers of oxidative stress and lipid peroxidation. In this article, we investigated the cytotoxicity of different nanoparticles and the degree of cellular membrane damage by using F2-isoprostanes as biomarkers after exposure to nanoparticles. The human lung epithelial cell line A549 was exposed to four silica and metal oxide nanoparticles: SiO2 (15 nm), CeO2 (20 nm), Fe2O3 (30 nm), and ZnO (70 nm). The levels of F2-isoprostanes were determined by using high-performance liquid chromatography/mass spectrometry. The F2-isoprostanes’ peak was identified by retention time and molecular ion m/z at 353. Oasis HLB cartridge was used to extract F2-isoprostanes from cell medium. The results showed that SiO2, CeO2, and ZnO nanoparticles increased F2-isoprostanes levels significantly in A549 cells. Fe2O3 nanoparticle also increased F2-isoprostanes level, but was not significant. This implied that SiO2, CeO2, ZnO, and Fe2O3 nanoparticles can cause cell membrane damage due to the lipid peroxidation. To the best of our knowledge, this is the first report on the investigation of effects of cellular exposure to metal oxide and silica nanoparticles on the cellular F2-isoprostanes levels. 相似文献