首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   57篇
  免费   0篇
  国内免费   1篇
安全科学   2篇
废物处理   8篇
环保管理   7篇
综合类   2篇
基础理论   8篇
污染及防治   20篇
评价与监测   5篇
社会与环境   6篇
  2022年   1篇
  2017年   1篇
  2016年   3篇
  2015年   2篇
  2014年   8篇
  2013年   5篇
  2012年   5篇
  2011年   8篇
  2010年   5篇
  2008年   5篇
  2007年   4篇
  2006年   4篇
  2005年   1篇
  2004年   1篇
  2003年   1篇
  2001年   1篇
  1999年   1篇
  1987年   1篇
  1986年   1篇
排序方式: 共有58条查询结果,搜索用时 15 毫秒
31.
In recent years, research on ozone variability has mainly focused on the analysis of its trend. Additionally some studies have analyzed the annual, seasonal and day-to-day ozone variations. However, intra-diurnal total ozone variations are notably less explored. Thus, the main objective of this paper is to analyze the diurnal variability of total ozone column (TOC) as recorded by a Brewer spectrophotometer in Madrid (Spain). The results show that about 90% of days present non-negligible diurnal variability, indicating that, in general, it should not be assumed that TOC remains constant throughout a particular day in urban areas. In addition, this variability has a notable seasonal behavior which should be considered (the spring and summer months show higher diurnal TOC variations than autumn and winter months). This pattern is likely caused by the diurnal photochemical processes in the lower troposphere related to the formation of tropospheric ozone near the earth’s surface at populated urban locations. Thus, these diurnal fluctuations in tropospheric ozone could explain part of diurnal TOC variations (between 20% and 70% depending on the mixing layer height).  相似文献   
32.
Beginning in 1960, the Spanish agricultural sector underwent an intensive process of development, resulting in important structural changes, not only in the sector itself, but also in the relationship of the agrarian system to natural resources. These changes were closely related to the growth of per capita income and Spain’s increasing integration into international markets. In the last five decades, the volume of Spanish agricultural trade has increased strongly, with a concomitant increase in the consumption of domestic water resources, requiring the construction of water infrastructure for irrigation. This paper examines the impact on water use in Spain during a period of economic modernization and trade liberalization. More specifically, we are interested in obtaining virtual water trade flow trends and identifying the major drivers responsible for these trajectories, via a decomposition analysis. Our results point to a large increase in virtual water exports and imports, primarily driven by the scale effect, that is, by the growing integration into international markets. The composition effect and changes in water intensity entailed a moderation in water consumption.  相似文献   
33.
ABSTRACT

Measurements of residual perchloroethylene (PCE), a dry-cleaning solvent associated with human health effects, were made in dry-cleaned acetate cloth to enable improved characterizations of both occupational and environmental exposure. A limited sample size (25 acetate cloths) was used to explore the extent of inter-dry-cleaner variability in residual PCE and to characterize the effect of the pressing operation on residual PCE. A new method, which uses carbon-disulfide as the direct extracting agent, proved effective in the analysis of residual PCE, with a recovery-efficiency ≈ 75%. Inter-dry-cleaner variability of residual PCE, although marginally statistically significant, was relatively low, showing only a fourfold range compared to a 5-order-of-magnitude range obtained from Kawauchi and Nishiyama1. Pairwise comparison of residual PCE in nonpressed versus pressed acetate samples revealed a statistically significant reduction (p < 0.008), which amounted to a consistent (among dry-cleaners) pressing-related removal efficiency of 75 ± 4%. A preliminary assessment of the source term associated with the pressing operation (mass PCE liberated per kg cloth dry-cleaned, SPCE ≈ 30 mg/kg) indicates a minor contribution to the average ambient air concentrations within dry-cleaning establishments.  相似文献   
34.
Shinn C  Marco A  Serrano L 《Chemosphere》2008,71(3):507-514
Several authors have suggested that nitrogen-based fertilizers may be contributing to the global amphibian decline. We have studied the impact of sodium nitrite on early aquatic stages of Epidalea calamita, Pelophylax perezi and Hyla meridionalis larvae from Do?ana National Park (coastal wetland) and P. perezi from Gredos Mountain (high mountain ponds), exposed during 10 to 16 days. After 8 days of exposure all P. perezi larvae from Do?ana presented 100% mortality at 5 mg l(-1)N-NO2(-) while E. calamita larvae mortality rates were significantly lower at that concentration after 15 days. However, for H. meridionalis at day 15 no deaths were registered at 5 mg l(-1)N-NO2(-) and at 20 mg l(-1)N-NO2(-) presented intermediate mortality rates. In Do?ana the 10 d LC50 of older H. meridionalis larvae was between 20 and 30 mg l(-1)N-NO2(-) whilst for P. perezi it was below 5 mg l(-1)N-NO2(-). These results indicate inter-specific variation of the sensitivity of larval amphibians to nitrite. Gredos Mountain P. perezi larvae exposed since the egg stage were highly sensitive to nitrite, with a 16 d LC50 below 0.5 mg l(-1)N-NO2(-). The same species in Do?ana had a 15 d LC50 between 5 and mg l(-1)N-NO2(-). These results suggest that there is also intra-specific variation in sensitivity of amphibian larvae to nitrite: mountain amphibian populations appear to be more sensitive to polluted environments than coastal populations. Geographic and genetic variation and evolutionary adaptation of tolerance may also be the keys to variation amongst populations of the same species.  相似文献   
35.
This paper aims to deepen the search for ecosystem-like concepts in indigenous societies by highlighting the importance of place names used by Quechua indigenous farmers from the central Bolivian Andes. Villagers from two communities in the Tunari Mountain Range were asked to list, describe, map and categorize the places they knew on their community’s territory. Results show that place names capture spatially explicit units which integrate biotic and abiotic nature and humans, and that there is an emphasis on topographic terms, highlighting the importance of geodiversity. Farmers’ perspectives differ from the classical view of ecosystems because they ‘humanize’ places, considering them as living beings with agency. Consequently, they do not make a distinction between natural and cultural heritage. Their perspective of the environment is that of a personalized, dynamic relationship with the elements of the natural world that are perceived as living entities. A practical implication of the findings for sustainable development is that since places names make the links between people and the elements of the landscape, toponymy is a tool for ecosystem management rooted in indigenous knowledge. Because place names refer to holistic units linked with people’s experience and spatially explicit, they can be used as an entry point to implement an intercultural dialogue for more sustainable land management.  相似文献   
36.
The embryonic development and the level of dependency of the embryos from the maternal organism were investigated for Centroscymnus coelolepis. During the development, there is a 22–32% loss of organic matter and gains of 95–122% and 29–46% on moisture and inorganic matter, respectively. Only 28–48% of the initial yolk energy is conserved in embryos, being the remaining used in catabolism. In late pregnancy, the epithelium thickness of uterine villi decreases and vascularity increases. Results suggest that only water and minerals are transferred from the mother to the embryos. Monounsaturated fatty acids are the main type of fatty acids representing 48% of the total yolk fatty acid content, followed by polyunsaturated (30%) and saturated fatty acids (18–21%).  相似文献   
37.
A survey on the presence of pharmaceuticals in urban wastewater of a Spanish Mediterranean area (Castellon province) was carried out. The scope of the study included a wide variety of pharmaceuticals belonging to different therapeutical classes. For this purpose, 112 samples, including influent and effluent wastewater, from different conventional wastewater treatment plants were collected. Two monitoring programmes were carried out along several seasons. The first was in June 2008 and January 2009, and the second in April and October 2009. During the first monitoring, the occurrence of 20 analytes in 84 urban wastewater samples (influent and effluent) was studied. The selection of these pharmaceuticals was mainly based on consumption. From these, 17 compounds were detected in the samples, with analgesics and anti-inflammatories, cholesterol lowering statin drugs and lipid regulators being the most frequently detected groups. 4-Aminoantipyrine, bezafibrate, diclofenac, gemfibrozil, ketoprofen, naproxen and venlafaxine were the compounds most frequently found. In the highlight of these results, the number of analytes was increased up to around 50. A lot of antibiotic compounds were added to the target list as they were considered “priority pharmaceuticals” due to their more potential hazardous effects in the aquatic environment. Data obtained during the second monitoring programme (spring and autumn) corroborated the results from the first one (summer and winter). Analgesics and anti-inflammatories, lipid regulators together with quinolone and macrolide antibiotics were the most abundant pharmaceuticals. Similar median concentrations were found over the year and seasonal variation was not clearly observed. The removal efficiency of pharmaceuticals in the wastewater treatment plants was roughly evaluated. Our results indicated that elimination of most of the selected compounds occurred during the treatment process of influent wastewater, although it was incomplete.  相似文献   
38.
The aim of this work was to assess possible effects of the Prestige oil spill on reproduction parameters of mussels along the Galician and Bay of Biscay coast. Studied endpoints included sex ratio, gonad histology and vitellogenin-like proteins using the alkali-labile phosphate (ALP) method. A high prevalence of haemocytic infiltration of follicles and severe oocyte atresia was found in most localities in April 2003. Spawning gonads were observed in most impacted populations in the same sampling. In April 2004 mature small sized follicles were observed. No histopathological changes were observed in April 2005 and 2006, except a high prevalence of necrotic gametes in 6 out of 22 localities in April 2006. Female ALP levels showed high interindividual variability in April 2004, which was reduced in April 2005 and 2006. No xenoestrogenic effects were observed in male mussels. Overall, gamete alterations were detected during 2003-2004 and a recovery trend was observed afterwards.  相似文献   
39.
40.
The manufacturing of orange juice generates high volumes of orange peel waste which should not be deposited in landfill according to current recommendations. Furthermore, glycerol is a compound co-generated in biodiesel manufacturing, but the volume generated is higher than the current demand for pure glycerol. The anaerobic co-digestion of orange peel waste with residual glycerol could reduce the inhibitory effect of some compounds and provide a correct nutrient balance. Under mesophilic temperature and semi-continuous conditions, a mixture of orange peel waste-residual glycerol of 1:1 (in COD) operated favorably for organic loads up to 2.10 g VS/L. At higher organic loads, the accumulation of volatile fatty acids (VFA) and a decrease in the pH caused process destabilization. The methane yield coefficient was quite constant, with a mean value of 330 ± 51 mLSTP/g VSadded, while the organic loading rate (OLR) reached a mean value of 1.91 ± 0.37 kg VS/m3 d (17.59 ± 2.78 kg mixture/m3 d) and the hydraulic retention time (HRT) varied in a range of 8.5–30.0 d.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号