全文获取类型
收费全文 | 219篇 |
免费 | 1篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 7篇 |
废物处理 | 12篇 |
环保管理 | 25篇 |
综合类 | 22篇 |
基础理论 | 35篇 |
污染及防治 | 91篇 |
评价与监测 | 14篇 |
社会与环境 | 16篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 3篇 |
2022年 | 13篇 |
2021年 | 21篇 |
2020年 | 6篇 |
2019年 | 2篇 |
2018年 | 10篇 |
2017年 | 8篇 |
2016年 | 9篇 |
2015年 | 7篇 |
2014年 | 10篇 |
2013年 | 16篇 |
2012年 | 5篇 |
2011年 | 16篇 |
2010年 | 12篇 |
2009年 | 11篇 |
2008年 | 16篇 |
2007年 | 10篇 |
2006年 | 11篇 |
2005年 | 6篇 |
2004年 | 10篇 |
2003年 | 6篇 |
2002年 | 4篇 |
2001年 | 1篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有223条查询结果,搜索用时 31 毫秒
201.
José Delcán María Orera Rafael Linares Dolores Saavedra Angustias Palomar 《黑龙江环境通报》2004,24(8):635-637
We report a 16-week-gestation foetus obtained by voluntary abortion after prenatal diagnosis, in which a ring chromosome 22 was observed with deletion of the 22q13.3 region. A prenatal study of the amniotic fluid by standard chromosome technique with G bands and FISH (fluorescence in situ hybridisation) was performed. After the abortion, the anatomopathological study of the obtained foetus was carried out. Morphological and histological analysis of the foetus did not reveal severe physical abnormalities, although alterations of the nervous system were observed consisting of corpus callosum, fornix and septum pellucidum agenesia. It could be that the genes in this region that were involved in the development of the central nervous system were responsible for the alterations found in the morphological study. The wide range of manifestations observed in patients with this cytogenetic alteration is probably due to size differences in the deleted region. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
202.
A comparison of the quantification of a specific microbial group in activated sludge by fluorescent in-situ hybridization, coupled with either direct microscopic counting or flow cytometry, was performed using an enhanced-biological-phosphorus-removal, sequencing-batch reactor. The population dynamics of Candidatus Accumulibacter phosphatis (Cand. A. phosphatis) was evaluated during two separate runs of the reactor. With the operational conditions used, Cand. A. phosphatis was enriched until a failure in the pH controller eliminated its ecological advantage. As a result, the comparison of quantification techniques included Cand. A. phosphatis concentrations as low as 11% and as high as 96% of the total cells in the samples. The analysis demonstrated that, regardless of the particular limitations of each technique, both provided similar results when the activated-sludge flocs were easily dispersed. However, when the activated-sludge samples contained flocs that were difficult to disperse, flow cytometry failed to provide quantitative results. 相似文献
203.
Modified Whittaker plots as an assessment and monitoring tool for vegetation in a lowland tropical rainforest 总被引:3,自引:0,他引:3
Campbell P Comiskey J Alonso A Dallmeier F Nuñez P Beltran H Baldeon S Nauray W de la Colina R Acurio L Udvardy S 《Environmental monitoring and assessment》2002,76(1):19-41
Resource exploitation in lowland tropical forests is increasingand causing loss of biodiversity. Effective evaluation and management of the impacts of development on tropical forests requires appropriate assessment and monitoring tools. We proposethe use of 0.1-ha multi-scale, modified Whittaker plots (MWPs) to assess and monitor vegetation in lowland tropical rainforests.We established MWPs at 4 sites to: (1) describe and comparecomposition and structure of the sites using MWPs, (2) compare these results to those of 1-ha permanent vegetation plots (BDPs),and (3) evaluate the ability of MWPs to detect changes in populations (statistical power). We recorded more than 400 species at each site. Species composition among the sites was distinctive, while mean abundance and basal area was similar. Comparisons between MWPs and BDPs show that they record similarspecies composition and abundance and that both perform equallywell at detecting rare species. However, MWPs tend to record morespecies, and power analysis studies show that MWPs were more effective at detecting changes in the mean number of species of trees 10 cm in diameter at breast height (dbh) and in herbaceous plants. Ten MWPs were sufficient to detect a change of 11% in the mean number of herb species, and they were able to detect a 14% change in the mean number of species of trees 10 cm dbh. The value of MWPs for assessment and monitoringis discussed, along with recommendations for improving the sampling design to increase power. 相似文献
204.
César Gómez-Lahoz Rafael García Delgado José Miguel Rodríguez Maroto David J. Wilson 《Environmental monitoring and assessment》1996,43(2):153-179
Model calculations are used to explore the effects of the kinetics of diffusion of dissolved organic compounds into and out of low-permeability porous materials and of the rate of solution of nonaqueous phase liquid (NAPL) droplets (into the aqueous phase) on the rate of cleanup of contaminated aquifers. Two models are presented: (1) the flushing of organic compounds initially distributed as NAPL droplets in a fracture in a porous rock aquifer, and (2) the removal of organic compounds initially present as NAPL in an aquifer containing low-permeability porous clay lenses. NAPL droplet size is found to be of much less importance than the spacing of the fractures in the porous rock in the first model or the thickness of the clay lenses in the second. 相似文献
205.
A pilot-scale horizontal flow constructed wetland (HFCW) system planted with common reed (Phragmites sp.) was constructed to study how hydraulic loading rate (HLR), aspect ratio, water depth, and granular medium affect to the fate of several organic matter degradation intermediates namely, acetic acid (HAc), isovaleric acid (Isoval), and dimethylsulfide (DMS). ANOVA statistical analysis performed on the data set of 8 months of operation shows that the HLR and the water depth are two major factors that control the performance of HFCWs for the target analytes. A clear difference in the HFCW effluent concentrations was obtained according to water depth. Effluents of the shallow water depth contained lower DMS (1.05-1.44 microg l-1), HAc (7.91-10.9 mg l-1), and Isoval (0.11-0.15 mg l-1) concentrations than the deeper beds (DMS: 1.68-2.40 microg l-1; HAc: 9.29-14.4 mg l-1, and Isoval: 0.20-0.31 mg l-1). Such differences could be accounted to the different formation and consumption rates of the organic matter degradation intermediates, which is related with the redox potentials (E). Indeed, it could lead to different biochemical reactions of organic matter degradation according with the E value. HLR has a statistically significant influence on the effluent HAc, Isoval, and DMS concentrations. Seasonal variability of effluent HAc concentration shows that it is independent on the HAc loading. While the loading showed no seasonal pattern, the removal efficiency was clearly higher in cold months, which suggests a predominant internal production of HAc in HFCWs in the warm season from the accumulated organic particulate matter. Similar results were also found when Isoval and DMS were considered. 相似文献
206.
Paul Chiou Wei Tang Che-Jen Lin Hsing-Wei Chu Rafael Tadmor T. C. Ho 《Environmental Modeling and Assessment》2009,14(5):645-659
Speciated samples of PM2.5 were collected at the Big Bend site from July of 2003 to June 2006 and the McDonald Observatory site from July of 2003 to
August of 2005 in southwestern Texas, respectively, by the US Environmental Protection Agency. A total of 175 samples for
the Big Bend site and 105 samples for the McDonald Observatory site with 52 species were measured; however, 30 and 32 species
from the Big Bend and McDonald Observatory sites, respectively, were excluded because of too much below-detection-limit data.
Due to the laboratory change about November 1 of 2004 and possible analytical artifacts, phosphorous was excluded as well.
Among the species excluded, 31 species are common to both sites. The two data sets were analyzed by positive matrix factorization
to infer the sources of PM observed at the two sites. The analysis resolved five source-related factors for Big Bend and four
for McDonald Observatory. Sulfate-rich secondary aerosol, coal burning, motor vehicle/road dust, and a mixed factor were identified
as common sources to both sites. The other factor identified for Big Bend is related to soil. Sulfate mainly exists as ammonium
salts. The sulfate-rich secondary aerosols account for about 62% and 66% of the PM2.5 mass concentration at the two sites, respectively. The highest concentration of Si associated with Ca, Fe,
\textSO42 - {\text{SO}}_4^{2 - } , and organic carbon at the two sites was possibly attributed to the coal-fired power plants in the region. Basically, the
factor of sulfate and coal burning at the two sites showed similar chemical composition profiles and seasonal variation that
reflect the regional characteristics of these sources. The regional factors of sulfate, coal burning, and soil showed predominantly
low-frequency variations; however, the area-related and/or local factors showed both high and low frequency variations. The
motor vehicle/road dust and the mixed factors were likely to be area-related and/or local source. 相似文献
207.
208.
Construction and demolition waste management process modeling: a framework for the Brazilian context
Esguícero Fábio José Deus Rafael Mattos Battistelle Rosane Martins Benedito Luiz Bezerra Barbara Stolte 《Journal of Material Cycles and Waste Management》2021,23(5):2037-2050
Journal of Material Cycles and Waste Management - In Brazil, municipal public authorities are responsible for construction and demolition (C&D) waste management. However, there is a lack of... 相似文献
209.
José Rafael García-March Miguel Ángel Sanchís Solsona A. M. García-Carrascosa 《Marine Biology》2008,153(4):689-698
Gaping activity of bivalve molluscs is closely related to physiological process such as breathing, nutrition, responses to
environmental stimuli and follows rhythmic cycles in many species. Although the alternation of Sun and Moon is the major entraining
agent for the daily living clock-driven rhythms, cyclic extrinsic environmental factors can also modulate gaping activity.
Therefore, laboratory experimental conditions can alter the natural behaviour of bivalves, hindering the interpretation of
observations. Many features of Pinna nobilis physiology are poorly known, gaping activity not being an exception. To reduce the knowledge gap on this regard, we performed
a study on the species gaping activity. The research was designed to be carried out in situ, in order to avoid the interference
of laboratory conditions in the observations. To this end, we designed and fabricated a new electronic system composed by
a data logger and a sensor formed by multiple reed switches activated by a single magnet. The system is autonomous and can
record gaping activity of subtidal bivalves in potentially any type of subtidal environment. Furthermore, it requires little
framework for the installation. With this system, we monitored 10 individuals in periods ranging between 3 and 21 days, for
up to a total of 98 days. The records have shown that far from being all day open, as previously suggested, P. nobilis follows marked circadian and circalunar rhythms of gaping activity. Individuals usually close the valves during night, sometimes
for more than 12 h. The repetition of patterns observed made it possible to distinguish between two main behaviours: (1) night-closing
related with sunset and (2) night-opening related with the Moon visible in the sky with the disc illuminated more than 50%.
Another two less common trends were also observed: (3) day-closing and (4) night-opening with no visible Moon. 相似文献
210.
The sequential extraction procedures described by Tessier et al., McGrath and Cegarra, and Gimeno-García et al. were compared
to investigate trace element (As, Cr, Cu, Pb, and Zn) partitioning patterns and extraction efficiency in three contaminated
soils from Mediterranean regions of Spain. Soils were selected from Onda (Castellón) (S1), Aznalcóllar (Sevilla) (S2), and
Silla (Valencia) (S3). S1 was a soil contaminated with Pb and Zn after dumping of wastes from the manufacture of ceramic tiles,
S2 was polluted accidentally with a highly acid and As-concentrated sludge from mining activities, and S3 was a soil with
a high Cr content from tannery sludge disposal. Trace element distribution in the soils—soluble, exchangeable, organically
bound, precipitated with carbonates, bound to iron and manganese oxides, and precipitated with sulfides fractions—varied significantly
according to the extraction procedure used. In addition, different extraction efficiencies were found for the three sequential
extraction procedures compared. Finally, the trace elements studied showed different and specific distribution patterns between
the various soil fractions examined. 相似文献