全文获取类型
收费全文 | 161篇 |
免费 | 0篇 |
专业分类
安全科学 | 4篇 |
废物处理 | 2篇 |
环保管理 | 24篇 |
综合类 | 15篇 |
基础理论 | 36篇 |
污染及防治 | 49篇 |
评价与监测 | 22篇 |
社会与环境 | 8篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 2篇 |
2016年 | 8篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 14篇 |
2012年 | 24篇 |
2011年 | 14篇 |
2010年 | 11篇 |
2009年 | 8篇 |
2008年 | 9篇 |
2007年 | 12篇 |
2006年 | 10篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1985年 | 1篇 |
1981年 | 1篇 |
1977年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有161条查询结果,搜索用时 15 毫秒
151.
Santiago Guillermo Ceballos Enrique Pablo Lessa Mariela Fernanda Victorio Daniel Alfredo Fernández 《Marine Biology》2012,159(3):499-505
Phylogeography studies add insights into the geographic and evolutionary processes that underline the genetic divergence of
populations. This work examines the geographic genetic structure of the Patagonian blennie, Eleginops maclovinus, a notothenioid (Perciformes) endemic to South American temperate and sub-Antarctic waters, using mitochondrial DNA cytochrome
b sequences. We found 58 haplotypes in the analysis of 261 individual sequences of 833 base pairs in length. Among-population
variance was very low (1.62%) and many haplotypes were shared between several populations across the species geographic range.
Genetic differentiation was not consistent with a simple model of isolation by distance, possibly suggesting a lack of equilibrium
between gene flow and local genetic drift. The analysis of mismatch distributions, neutrality tests, and the Bayesian Skyline
Plot showed a pattern consistent with a recent population expansion event that may have taken place during the Middle Pleistocene. 相似文献
152.
Vullo DL Ceretti HM Hughes EA Ramírez S Zalts A 《Environmental monitoring and assessment》2005,105(1-3):81-97
Las Catonas stream (Buenos Aires Metropolitan Area) receives a complex mixture of pollutants from point and diffuse sources because of the agricultural, industrial and urban land uses of its basin. Widespread detection of heavy metals exceeding aquatic life protection levels has occurred in monitoring reconnaissance studies in surface and pore water. As a result of the screening of Cu, Cd, Zn and Pb resistant/tolerant and culturable microbiota, B101N and 200H strains (Pseudomonas fluorescens or putida) were isolated and selected for further studies. They showed 65% Cd and 35% Zn extraction efficiency from aqueous phase. The potential use of these strains in wastewater treatment is currently investigated in order to contribute to decrease heavy metal pollution, a problem affecting every stream of Buenos Aires Metropolitan Area. 相似文献
153.
The removal of particulate material in the aeration basin of the activated sludge process is mainly attributed to bioflocculation and hydrolysis of particulate substrate. The bioflocculation process in the aeration tank of the activated sludge process occurs only under favorable conditions in the system, and several common operational parameters affect its performance. The principal objective of this research was to observe the effect of mixed liquor suspended solids, solids retention time (SRT), and extracellular polymer substances on the removal of particulate substrate by bioflocculation. A first-order particulate removal expression, based on flocculation, accurately described the removal rates for supernatant suspended solids and colloidal chemical oxygen demand. Based on the results presented in this investigation, a mixed liquor concentration of approximately 2200 mg/L, an SRT of at least 3 days, and a contact time of 30 minutes are needed for relatively complete removal of the particulate substrate in a plug-flow reactor. 相似文献
154.
Sarah Samadi Lionel Bottan Enrique Macpherson Bertrand Richer De Forges Marie-Catherine Boisselier 《Marine Biology》2006,149(6):1463-1475
Previous studies have suggested that the high diversity associated with the Norfolk seamounts (Southwest Pacific) could reflect endemism resulting from limited dispersal due to hydrological phenomena. Crustaceans of the family Galatheidae are thoroughly studied in the New Caledonia economic zone permitting the analysis of species distribution pattern between the New Caledonia slope and Norfolk ridge seamounts. This analysis has shown that, qualitatively, the same species are sampled on seamounts and on the New Caledonia slope. Local endemism was never detected. However, on each seamount, and therefore on a small surface, a very high number of species are usually sampled, suggesting that seamounts are biodiversity hot spots. Then, to evaluate whether the seamounts constitute patches of isolated habitat, we explore the pattern of genetic diversity within several species of crustaceans and gastropods. Analysis of the intra-specific genetic structure using the mitochondrial marker COI reveals that populations of two Galatheidae species (Munida thoe and Munida zebra), polymorphic for this marker, are genetically not structured, both among seamounts and between the seamounts and the island slope. The genetic structure over a similar sampling scheme of two Eumunida species (Chirostylidae, the sister family of Galatheidae) and a planktotrophic gastropod (Sassia remensa) reveals a similar pattern. Population structure is observed only in Nassaria problematica, a non-planktotrophic gastropod with limited larvae dispersal. Thus, the limitation of gene flow between seamounts appears to be observed only for species with limited dispersal abilities. Our results suggest that the Norfolk seamounts rather than functioning as areas of endemism, instead, may be highly productive zones that can support numerous species in small areas. 相似文献
155.
Enrique Morán-Tejeda Antonio Ceballos-Barbancho José Manuel Llorente-Pinto Juan Ignacio López-Moreno 《Regional Environmental Change》2012,12(1):17-33
Land-use and land-cover changes have attracted substantial scientific interest in recent years because of their marked influence
on hydrological cycles. In developed countries of the Mediterranean basin, the generalized revegetation and forest growth
in mountainous areas that occurred during the last five decades are negatively affecting the evolution of water resources
in headwaters. In this study, changes in land cover in the Duero River Basin (northern Spain) during the last 50 years were
analyzed and their role in hydrological evolution was estimated. For this purpose, step-wise linear regressions were developed
to estimate the evolution of runoff as a function of climate (precipitation and temperatures). The results show a significant
expansion of forest cover in the headwaters, although it has been more extensive in the mountains to the north of the basin
than to the south. River discharges in the headwaters underwent a generalized decline during the study period (1961–2006),
but precipitation over the same period did not show an appreciable trend. In the absence of noticeable trends in removal of
water for human consumption, our results indicate that revegetation is contributing to the observed hydrological decline.
Our hypothesis is confirmed because of the greater divergence in the evolution of precipitation and runoff in the northern
headwaters (more forest growth) than in the south headwaters (less forest growth). Results suggest that further increases
in forest area will enhance hydrological decline and highlight the importance of integrating land-cover information in water
availability assessments in a region where water is a strategic resource. 相似文献
156.
The present study assesses the sustainability of ethanol produced from sugarcane and examines the environmental feasibility of a large-scale production through the use of: fossil fuel embodied energy and Emergy Assessment including farm and industrial production phases. The study indicates that about 1.82 kg of topsoil eroded, 18.4 l of water and 1.52 m2 of land are needed to produce 1 l of ethanol from sugarcane. Also, 0.28 kg of CO2 is released per liter of ethanol produced. The energy content of ethanol is 8.2 times greater than the fossil-based energy required to produce it. The transformity of ethanol is about the same as those calculated for fossil fuels. The Renewability of ethanol is 30%, a very low value; other emergy indices indicate important environmental impacts as well as natural resources consumption. The results obtained indicate that sugarcane and ethanol production present low renewability when a large-scale system is adopted. 相似文献
157.
Félix-Valenzuela Leticia Molina-Chavarria Alejandro Enríquez-Hernández Carmen Itzé Bolado-Martínez Enrique Durazo-Arvizu María de los Ángeles Dórame-Castillo Roberto Cano-Rangel Manuel Alberto Mata-Haro Verónica 《Food and environmental virology》2020,12(4):355-360
Food and Environmental Virology - Norovirus (NoV) is an important etiological agent of diarrhea in children and adults. In Mexico, NoV screening is not routinely performed. NoV is highly infectious... 相似文献
158.
The spiny lobster, Panulirus argus, is predominantly nocturnal, remaining inside shelters during the day and foraging outside at night, presumably to minimize
predation risk. Predation risk generally decreases with increasing lobster size. Therefore, this study examined the hypothesis
that size would influence this basic circadian pattern. Video cameras continuously recorded the shelter occupancy of juvenile
lobsters (n = 72) having a carapace length (CL) of 30–62 mm that were tethered to shelters in a shallow reef lagoon. The lobsters’ shelter
occupancy was 100% during the day, but declined linearly from shortly before sunset to a minimum of 50% shortly after midnight
and then increased linearly, reaching 100% by 1 h after sunrise. The percent time the lobsters spent in the shelters followed
a similar trend, but there was wide variability at night (0–100%) for individual lobsters. Lobsters left their shelters 2–30
times night−1, with a majority of excursions lasting <10 min. These results suggest that juvenile P. argus minimize predation risk by remaining in their shelters as long as possible but offset the energetic cost of this behavior
by foraging close to their shelters for several short periods at night. This emergence pattern contrasts with those of early
benthic phase lobsters (<15 mm CL), which seldom leave their shelters, and adults (>80 mm CL), which have a dusk/early evening
peak in activity and leave the shelter for extended periods of time during the night. Furthermore, a minimum shelter occupancy
in the middle of the night appears especially well adapted to avoid exposure to daytime predators. Videotaped observations
also included interactions between lobsters and two dominant lobster predators, the triggerfish, Balistes capriscus, and the octopus Octopus cf. vulgaris. Lobsters responded differently to these predators: remaining in the shelter when attacked by a triggerfish and fleeing the
shelter when attacked by an octopus. Triggerfish were nearly twice as likely to attack a lobster that was outside of the shelter
than inside. Once under attack, however, a lobster had nearly the same chance of surviving if it was inside or outside. Results
suggest that the patterns of shelter use and emergence change as lobsters grow, probably reflecting the interplay between
perception of predation risk and the need to forage.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
159.
Specific-site data of metal concentration in cattle manure from NW Spain and a multicompartment fate and exposure model were used to evaluate metal fate and the main routes of exposure after a 100 year period of application of cattle manure as fertiliser in pastureland. Risk assessment was performed as a probabilistic analysis, and using a conservative worst-case exposure scenario. An accumulation model was used to predict the metal concentration in each environmental medium of concern. The incremental risk was estimated for the population inhabiting the surroundings of the area by a general multiexposure model. Monte Carlo simulations were performed to analyse uncertainty of the results. Furthermore, a sensitivity analysis was carried out to identify the contribution to variance by the different metals and exposure routes. Among the five pathways evaluated, the ingestion of meat and milk from cattle grazing in the area represents the main contribution to total exposure. The results indicate that the incremental risk to human health for people living in the surroundings of pasturelands due to continuous application of cattle manure after a 100 year period are not negligible for the metals considered (Cd, Cu, Ni, Pb and Zn), posing a total Reasonable Maximum Exposure (RME) of 0.75, being the ingestion of meat the main exposure pathway. 相似文献
160.
Lutts S Lefèvre I Delpérée C Kivits S Dechamps C Robledo A Correal E 《Journal of environmental quality》2004,33(4):1271-1279
To identify Cd- and Zn-accumulating plants exhibiting a high growth rate, seeds from the halophyte species Mediterranean saltbush (Atriplex halimus L.) were collected on a heavy-metal-contaminated site in southeastern Spain (Llano del Beal, Cartagena). Seedlings from this ecotype were exposed for 3 wk to 0.1 mM Cd or Zn in a nutrient solution in a fully controlled environment. All plants remained alive and no significant growth inhibition was recorded until the end of the experiment. Mean Cd and Zn accumulation in aerial parts was 830 and 440 mg kg(-1), respectively, and the rate of metal translocation even increased with the duration of stress exposure. Resistance to heavy metals in this species may be partly linked to precipitation of Cd in oxalate crystals in the stems. A Cd-induced decrease in glutathione concentration also suggests that phytochelatins overproduction may occur in these conditions. We conclude that Mediterranean saltbush, which is able to produce up to 5 Mg dry matter ha(-1) yr(-1), may be an effective species for phytoextraction and should be tested for this purpose in field conditions. 相似文献