全文获取类型
收费全文 | 167篇 |
免费 | 1篇 |
专业分类
安全科学 | 5篇 |
废物处理 | 2篇 |
环保管理 | 25篇 |
综合类 | 16篇 |
基础理论 | 42篇 |
污染及防治 | 49篇 |
评价与监测 | 21篇 |
社会与环境 | 7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 | 3篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 8篇 |
2015年 | 4篇 |
2014年 | 4篇 |
2013年 | 14篇 |
2012年 | 24篇 |
2011年 | 13篇 |
2010年 | 11篇 |
2009年 | 9篇 |
2008年 | 9篇 |
2007年 | 12篇 |
2006年 | 10篇 |
2005年 | 4篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1985年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有168条查询结果,搜索用时 453 毫秒
161.
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
162.
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
163.
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
164.
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
165.
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
166.
Nuria Castell Enrique Mantilla Ariel F. Stein Rosa Salvador Millán Millán 《Environmental Modeling and Assessment》2011,16(6):565-576
During the central months of the year, southwestern Spain is under strong insolation and weak synoptic forcing, promoting
the development of sea breezes and mountain-induced winds and creating recirculations of pollutants. The complex topography
of the Southwestern Iberia Peninsula induces the formation of vertical layers, into which the pollutants are injected and
subjected to long-distance transport and compensatory subsidence. The characteristics of these highly complex flows have important
effects on the pollutant dispersion. Air pollution studies in very complex terrains require high-resolution modelling for
resolving the flow dynamics. This paper shows the results obtained from using the MM5-CAMx multiscale-nested air quality model
to relate the sensitivity regimes for ozone, nitrogen oxides and volatile organic compounds in an area of high geographical
complexity. The article assesses the impact on the hourly and eight-hourly maximum daily ozone concentrations of four reduction
strategies during two ozone pollution episodes. This analysis of the ozone response has led to a preliminary evaluation of
the effectiveness of the most common control strategies: traffic, industry, mixed traffic and industry, and closure of some
of the largest industries (oil and petrochemical refineries). Photochemical indicators show that ozone chemistry in southwestern
Spain is strongly sensitive to NO
x
. However, volatile organic compound-sensitive points are found in areas with anthropogenic influence (highways, cities and
industrial parks). Our results indicate that reductions in road traffic lead to ozone reductions over large areas, whereas
reductions in industrial emissions, despite sometimes showing greater decreases in the maximum hourly and eight-hourly ground-level
ozone levels, lead to ozone reductions in a local area only. In the control study case, with the oil refinery and the petrochemical
plants closed, decreases in ozone hourly concentrations are up to 40% higher than in the other emission control scenarios
studied. This analysis provides an assessment of the effectiveness of different policies for controlling precursor emissions
by comparing the modelled results for different scenarios. 相似文献
167.
Alastuey A Querol X Plana F Viana M Ruiz CR Sánchez de la Campa A de la Rosa J Mantilla E García dos Santos S 《Journal of the Air & Waste Management Association (1995)》2006,56(7):993-1006
A detailed physical and chemical characterization of coarse particulate matter (PM10) and fine particulate matter (PM2.5) in the city of Huelva (in Southwestern Spain) was carried out during 2001 and 2002. To identify the major emission sources with a significant influence on PM10 and PM2.5, a methodology was developed based on the combination of: (1) real-time measurements of levels of PM10, PM2.5, and very fine particulate matter (PM1); (2) chemical characterization and source apportionment analysis of PM10 and PM2.5; and (3) intensive measurements in field campaigns to characterize the emission plumes of several point sources. Annual means of 37, 19, and 16 microg/m3 were obtained for the study period for PM10, PM2.5, and PM1, respectively. High PM episodes, characterized by a very fine grain size distribution, are frequently detected in Huelva mainly in the winter as the result of the impact of the industrial emission plumes on the city. Chemical analysis showed that PM at Huelva is characterized by high PO4(3-) and As levels, as expected from the industrial activities. Source apportionment analyses identified a crustal source (36% of PM10 and 31% of PM2.5); a traffic-related source (33% of PM10 and 29% of PM2.5), and a marine aerosol contribution (only in PM10, 4%). In addition, two industrial emission sources were identified in PM10 and PM2.5: (1) a petrochemical source, 13% in PM10 and 8% in PM2.5; and (2) a mixed metallurgical-phosphate source, which accounts for 11-12% of PM10 and PM2.5. In PM2.5 a secondary source has been also identified, which contributed to 17% of the mass. A complete characterization of industrial emission plumes during their impact on the ground allowed for the identification of tracer species for specific point sources, such as petrochemical, metallurgic, and fertilizer and phosphate production industries. 相似文献
168.
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