全文获取类型
收费全文 | 223篇 |
免费 | 0篇 |
专业分类
安全科学 | 3篇 |
废物处理 | 7篇 |
环保管理 | 16篇 |
综合类 | 50篇 |
基础理论 | 50篇 |
环境理论 | 1篇 |
污染及防治 | 77篇 |
评价与监测 | 9篇 |
社会与环境 | 10篇 |
出版年
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2017年 | 9篇 |
2016年 | 12篇 |
2015年 | 8篇 |
2014年 | 10篇 |
2013年 | 16篇 |
2012年 | 16篇 |
2011年 | 20篇 |
2010年 | 11篇 |
2009年 | 10篇 |
2008年 | 19篇 |
2007年 | 14篇 |
2006年 | 7篇 |
2005年 | 6篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1977年 | 1篇 |
1971年 | 1篇 |
1967年 | 1篇 |
1963年 | 2篇 |
1949年 | 1篇 |
1920年 | 1篇 |
排序方式: 共有223条查询结果,搜索用时 703 毫秒
111.
Over a 24-h time scale, benthic decapods show complex patterns of behavioural activity associated with feeding. Information is scarce on the feeding rhythms of the burrowing decapod Nephrops norvegicus (L.), especially in those deep, benthic environments typical of western Mediterranean slopes, where the fishery of this species is highly developed. In the present study, the feeding of this species was determined by means of stomach sampling, from animals captured during four continuous 24-h cycles of trawl hauls at 100–110 m and 400–430 m, in October (the autumn equinox) and June (the spring solstice). A total of 3348 stomachs were analysed for fullness and classified by means of a visual, qualitative scale. A high proportion of the stomachs collected was empty (47.2%). Feeding rhythmicity was analysed by computing a percentage value of empty stomachs for each catch. Over 4 days, the percentage values presented marked fluctuations. Therefore, periodogram and form estimate analyses were performed on time series of percentages of empty stomachs, to determine the phase and periodicity of feeding rhythms. In October, animals ingested food during the daytime, presenting nocturnal peaks of empty stomachs at both depths considered in this study. In June, nocturnal peaks of empty stomachs were recorded for the slope, while a marked feeding arrhythmia was present on the shelf. A hypothesis linking feeding activity to endogenous rhythms in locomotion, cardiac and respiratory activities is presented to account for the animals diurnal ingestion, irrespective of the depth of distribution.Communicated by S.A. Poulet, Roscoff 相似文献
112.
Monitoring concentrations of persistent organic pollutants in the general population: the international experience 总被引:1,自引:1,他引:0
Porta M Puigdomènech E Ballester F Selva J Ribas-Fitó N Llop S López T 《Environment international》2008,34(4):546-561
Assessing the adverse effects on human health of persistent organic pollutants (POPs) and the impact of policies aiming to reduce human exposure to POPs warrants monitoring body concentrations of POPs in representative samples of subjects. While numerous ad hoc studies are being conducted to understand POPs effects, only a few countries are conducting nationwide surveillance programs of human concentrations of POPs, and even less countries do so in representative samples of the general population. We tried to identify all studies worldwide that analyzed the distribution of concentrations of POPs in a representative sample of the general population, and we synthesized the studies' main characteristics, as design, population, and chemicals analyzed. The most comprehensive studies are the National Reports on Human Exposure to Environmental Chemicals (USA), the German Environmental Survey, and the Arctic Monitoring and Assessment Programme. Population-wide studies exist as well in New Zealand, Australia, Japan, Flanders (Belgium) and the Canary Islands (Spain). Most such studies are linked with health surveys, which is a highly-relevant additional strength. Only the German and Flemish studies analyzed POPs by educational level, while studies in the USA offer results by ethnic group. The full distribution of POPs concentrations is unknown in many countries. Knowledge gaps include also the interplay of age, gender, period and cohort effects on the prevalence of exposures observed by cross-sectional surveys. Local and global efforts to minimize POPs contamination, like the Stockholm convention, warrant nationwide monitoring of concentrations of POPs in representative samples of the general population. Results of this review show how such studies may be developed and used. 相似文献
113.
J. W. Fourqurean N. Marbà C. M. Duarte E. Diaz-Almela S. Ruiz-Halpern 《Marine Biology》2007,151(1):219-232
Morphology, elemental content and isotopic composition of leaves of the seagrasses Posidonia oceanica and Cymodocea nodosa were highly variable across the Illes Balears, a Spanish archipelago in the western Mediterranean, and varied seasonally
at one site in the study area. The data presented in this paper generally expand the reported ranges of nitrogen, phosphorus,
iron and arsenic content and δ13C and δ15N for these species. Nitrogen and phosphorus content of P. oceanica leaves also showed significant seasonal variability; on an annual basis, P. oceanica leaves averaged 1.55% N and 0.14% P at this monitoring site. Both N and P were more concentrated in the leaves in winter
than in summer, with winter maxima of 1.76% N and 0.17% P and summer minima of 1.34% N and 0.11% P. There was no significant
annual pattern observed in the δ13C of P. oceanica leaves, but there was a repeated 0.6‰ seasonal fluctuation in δ15N. Mean annual δ15N was 4.0‰; δ15N was lowest in May and it increased through the summer and autumn to a maximum in November. Over the geographic range of
our study area, there were interspecific differences in the carbon, nitrogen and phosphorus content of the two species. Posidonia oceanica N:P ratios were distributed around the critical value of 30:1 while the ratios for C. nodosa were lower than this value, suggesting P. oceanica we collected was not consistently limited by N or P while C. nodosa tended toward nitrogen limitation. Nutrient content was significantly correlated to morphological indicators of plant vigor.
Fe content of P. oceanica leaves varied by a factor of 5×, with a minimum of 31.1 μg g−1 and a maximum of 167.7 μg g−1. Arsenic was present in much lower tissue concentrations than Fe, but the As concentrations were more variable; the maximum
concentration of 1.60 μg g−1 was eight times as high as the minimum of 0.20 μg g−1. There were interspecific differences in δ13C of the two species; C. nodosa was consistently more enriched (δ13C = −7.8 ± 1.7‰) than P. oceanica (−13.2 ± 1.2‰). The δ13C of both species decreased significantly with increasing water depth. Depth related and regional variability in the δ13C and δ15N of both species were marked, suggesting that caution needs to be exercised when applying stable isotopes in food web analyses. 相似文献
114.
Summary Young homing pigeons from the same German stocks were housed in two lofts, one in southern Germany, near Munich, and one in Italy, near Pisa. In the course of 1 year, two synchronized releases at sites 22–25 km NNW and SSE from each of the lofts were conducted every month. The pigeons that returned were released a second time at a site about 75 km east of home.Both initial homeward orientation and homing success were considerably better in Italy than in Germany. Annual cycles, with maxima in summer and minima in winter, were observed in both countries. They were most pronounced in initial orientation in Italy and in homing performance in Germany. Correlations between homing parameters and ambient temperature correspond to the annual cycles, but they do not indicate that the geographical and seasonal differences in homing behaviour are directly caused by actual temperature at the time of release.Our findings (together with earlier ones) suggest that environmental conditions may be variably conducive to the homeward orientation of pigeons according to spatial and temporal variations in the climate. 相似文献
115.
116.
Antonio D. Dorado Shafik Husni Guillem Pascual Carles Puigdellivol David Gabriel 《Waste management (New York, N.Y.)》2014,34(2):344-351
Emissions of volatile organic compounds (VOCs) from the compost maturation building in a municipal solid waste treatment facility were inventoried by solid phase microextraction and gas chromatography–mass spectrometry. A large diversity of chemical classes and compounds were found. The highest concentrations were found for n-butanol, methyl ethyl ketone and limonene (ppmv level). Also, a range of compounds exceeded their odor threshold evidencing that treatment was needed. Performance of a chemical scrubber followed by two parallel biofilters packed with an advanced packing material and treating an average airflow of 99,300 m3 h?1 was assessed in the treatment of the VOCs inventoried. Performance of the odor abatement system was evaluated in terms of removal efficiency by comparing inlet and outlet abundances. Outlet concentrations of selected VOCs permitted to identify critical odorants emitted to the atmosphere. In particular, limonene was found as the most critical VOC in the present study. Only six compounds from the odorant group were removed with efficiencies higher than 90%. Low removal efficiencies were found for most of the compounds present in the emission showing a significant relation with their chemical properties (functionality and solubility) and operational parameters (temperature, pH and inlet concentration). Interestingly, benzaldehyde and benzyl alcohol were found to be produced in the treatment system. 相似文献
117.
118.
N. Villa P. Riva D. Colombo E. Sala S. Mariani C. Zorloni F. Crosti L. Dalprà 《黑龙江环境通报》2001,21(10):801-805
The identification of small supernumerary marker chromosomes (SMCs) and the elucidation of their clinical significance remain two of the problems in classical human cytogenetics. We observed a small supernumerary ring in amniotic fluid cell cultures and identified its origin as r(2)(p10q11.2) and its extent by means of fluorescent in situ hybridisation (FISH). Uniparental disomy (UPD) was excluded by microsatellite analysis using polymorphic markers localised in the same region. On the basis of normal ultrasonographic checks, the patient decided to continue the pregnancy. A normal female was delivered at term and subsequent neonatal follow-ups confirmed the normal phenotype and development. In the present case, genetic counselling was not helpful because of the absence of reference cases. Detailed characterisation made it possible to correlate the normal baby phenotype with the trisomic 2p10-2q11.2 genomic region. Further molecular cytogenetic investigations of SMCs classified by DNA content and pregnancy outcome data should improve genetic counselling and risk evaluation. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
119.
Byron Calgua Anna Carratalà Laura Guerrero-Latorre Adriana de Abreu Corrêa Tamar Kohn Regina Sommer Rosina Girones 《Food and environmental virology》2014,6(4):260-268
Disinfection by low-pressure monochromatic ultraviolet (UVC) radiation (253.7 nm) became an important technique to sanitize drinking water and also wastewater in tertiary treatments. In order to prevent the transmission of waterborne viral diseases, the analysis of the disinfection kinetics and the quantification of infectious viral pathogens and indicators are highly relevant and need to be addressed. The families Adenoviridae and Polyomaviridae comprise human and animal pathogenic viruses that have been also proposed as indicators of fecal contamination in water and as Microbial Source Tracking tools. While it has been previously suggested that dsDNA viruses may be highly resistant to UVC radiation compared to other viruses or bacteria, no information is available on the stability of polyomavirus toward UV irradiation. Here, the inactivation of dsDNA (HAdV2 and JCPyV) and ssRNA (MS2 bacteriophage) viruses was analyzed at increasing UVC fluences. A minor decay of 2-logs was achieved for both infectious JC polyomaviruses (JCPyV) and human adenoviruses 2 (HAdV2) exposed to a UVC fluence of 1,400 J/m2, while a decay of 4-log was observed for MS2 bacteriophages (ssRNA). The present study reveals the high UVC resistance of dsDNA viruses, and the UV fluences needed to efficiently inactivate JCPyV and HAdV2 are predicted. Furthermore, we show that in conjunction with appropriate mathematical models, qPCR data may be used to accurately estimate virus infectivity. 相似文献
120.
Anna Carratalà Marta Rusiñol Jesús Rodriguez-Manzano Laura Guerrero-Latorre Regina Sommer Rosina Girones 《Food and environmental virology》2013,5(4):203-214
Environmental factors are highly relevant to the global dissemination of viral pathogens. However, the specific contribution of major effectors such as temperature and sunlight on the inactivation of waterborne viruses is not well characterized. In this study, the effect of temperature (7, 20, and 37 °C), UVB and UVA radiation on viral inactivation was evaluated in phosphate buffered saline (PBS), mineral water, wastewater, 1,000-fold diluted wastewater and seawater. The stability of human adenoviruses infectivity, known as human pathogens and indicators of fecal contamination, was monitored during 24 h, both in the dark and exposed to UV radiation by immunofluorescence assays. In the dark, no Human adenovirus (HAdV) inactivation was observed in PBS and mineral water at any of the temperatures studied, whereas at 37 °C in reactors with higher microbial concentration (wastewater, diluted wastewater, and seawater), decays between 2.5 and 5 log were recorded. UVB radiation showed a dramatic effect on HAdV inactivation and 6-log were achieved in all reactors by the end of the experiments. The effect of UVA showed to be dependent on the water matrix analyzed. At 20 °C, HAdV showed a 2-log decay in all reactors radiation while at 37 °C, results in wastewater, diluted wastewater, and seawater reactors were equivalent to those observed in the dark. These results suggest UVB radiation as the major environmental factor challenging viral inactivation, followed by biotic activity indirectly associated to higher temperatures and finally, by UVA radiation. 相似文献