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   286篇
  免费   4篇
  国内免费   7篇
安全科学   14篇
废物处理   14篇
环保管理   20篇
综合类   31篇
基础理论   57篇
环境理论   1篇
污染及防治   97篇
评价与监测   37篇
社会与环境   24篇
灾害及防治   2篇
  2024年   1篇
  2023年   2篇
  2022年   8篇
  2021年   14篇
  2020年   6篇
  2019年   4篇
  2018年   15篇
  2017年   13篇
  2016年   14篇
  2015年   7篇
  2014年   5篇
  2013年   22篇
  2012年   20篇
  2011年   12篇
  2010年   22篇
  2009年   14篇
  2008年   23篇
  2007年   18篇
  2006年   19篇
  2005年   5篇
  2004年   11篇
  2003年   11篇
  2002年   8篇
  2001年   1篇
  2000年   2篇
  1996年   1篇
  1993年   1篇
  1992年   4篇
  1991年   2篇
  1990年   2篇
  1988年   1篇
  1987年   1篇
  1985年   2篇
  1982年   1篇
  1980年   1篇
  1978年   1篇
  1964年   1篇
  1963年   1篇
  1962年   1篇
排序方式: 共有297条查询结果,搜索用时 15 毫秒
101.

Goal and Scope

Several studies show that the concentration of metals in mosses depends not only on metal deposition but also on factors such as moss species, canopy drip, precipitation, altitude, distance to the sea and the analytical technique used. However, contrasting results have been reported and the interpretation of the spatial variability of the metal accumulation in mosses remains difficult. In the presented study existing monitoring data from the European Heavy Metals in Mosses Surveys together with surface data on precipitation, elevation and land use are statistically analysed to assess factors other than emissions that have an influence on the metal accumulation in the mosses.

Main Features

Inference statistics and Spearman correlation analysis were applied to examine the association of the metal accumulation and the distance of the monitoring sites to the sea as well as the altitude. Whether or not significant differences of the metal loads in the mosses exist at national borders was examined with help of the U-test after Mann and Whitney. In order to identify and rank the factors that are assumed to have an influence on the metal uptake of the mosses Classification and Regression Trees (CART) were applied.

Results

No clear tendency could be derived from the results of the inference statistical calculations and the correlation analyses with regard to the distance of the monitoring site to the sea and the altitude. According to the results of the CART-analyses mainly the moss species, potential emission sources around the monitoring sites, canopy drip and precipitation have an effect on the metal bioaccumulation. Assuming that each participating country followed strictly the manual for sampling and sample preparation the results of the inference statistical calculations furthermore suggest that in most cases different techniques for digestion and analysis bias the measurements significantly.

Discussion

For the first time a national monitoring data base consisting of measurement data and metadata as well as surface information on precipitation, land use and elevation was applied to examine influence factors on the metal bioaccumulation in mosses. The respective results mirror existing knowledge from other national studies to a large extend, although further analyses are necessary to affirm the findings. These analyses should include data from other national monitoring programmes and should additionally be carried out with other decision tree algorithms than CART.

Conclusions

The local variability in the metal concentration in mosses can be uncovered in terms of predictors or underlying hidden causes by using CART. Ideally, such an approach should be applied across the whole of Europe. This will only be feasible if all participating countries provide additional information about site characteristics as currently is done in for example the German moss surveys.

Recommendations

The UNECE Metals in Mosses Survey experimental protocol should be improved in order to reduce the observed influences, to enhance standardisation, and to strengthen the quality control. This implies the integration of sampling site describing metadata into the assessment. Furthermore, basis research is needed to test the hypothesis concerning moss species-specific accumulation of depositions.

Perspectives

Provided that the presented results hold true in further analyses correction factors should be applied on the moss data in order to get the depicted spatial patterns and temporal trends of metal bioaccumulation unbiased. Such factors should be calculated for natural landscape units or ecoregions that are homogeneous with regard to climate, vegetation and altitude.  相似文献   
102.
The study illustrates the response of epiphytic lichens to changing atmospheric conditions in Central Europe, where the emission of air pollutants has significantly decreased from 1990, in the area in and around Bratislava City. Variation in concentrations of seven metal elements (Cu, Cd, Cr, Mn, Ni, Pb and Zn) in the thalli of Evernia prunastri, Hypogymnia physodes and Parmelia sulcata is assessed. Samples of these species were exposed in lichen bags in 39 sites throughout the territory of the city (more than 300 km(2)) during the period December 2006-February 2007. The samples were analyzed by AAS for metal element contents prior to and after exposure. The decrease in air pollution (for all studied elements by more than 90%) corresponded to a decrease in the accumulation of elements in lichen thalli, e.g. the contents of Pb decreased by 69% and of Cd by 34% on average. The results show also variations in accumulation between with different lichen species. The background values of metal element contents in thalli of H. physodes growing in situ were measured in semi-natural sites in Slovakia. It is suggested that these can be used as a reference in large-scale monitoring studies in Central Europe. Analysis of compatible data from the current study, and the study performed at the end of 1990s shows a significant decrease of metal elements in the air pollution load.  相似文献   
103.
104.
We present the first confirmed case by molecular analysis of a metaphyseal chondrodysplasia, McKusick type, in a 22-week fetus. Two novel compound heterozygous mutations, 64T> A and 79G > T, were found in the highly conserved regions of the RMRP gene. Twenty-two heterozygous g.1018 T> C mutations, two homozygous g.1018 T> C mutations, two heterozygous insertion mutations g.799_g.800insC and one heterozygous insertion mutation g.849_g.850insT were found among 100 normal controls. Careful radiological examination of the fetus for skeletal dysplasia allowed definitive diagnosis, proper genetic counselling and future prenatal diagnosis. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
105.
Many Eastern European countries suffer the lack of data on concentrations of persistent organic pollutants in the environmental matrices. This absence of information is preventing the local authorities from taking the adequate actions to protect the people and environment. This is even more alarming in the countries recently affected by the wars where the chemicals released to the environment during the military operations can cause a significant ecological damage and health effects on the population. A potential of passive air sampling technique as a tool capable of providing seasonally and spatially resolved information about the local sources and levels of contamination was explored in this study as a first step to the establishment of a cost-effective long-term monitoring in this area. The passive air samplers proved to be a powerful technique capable of detecting the concentrations ranging over four orders of magnitude providing the information very comparable with the conventional techniques.  相似文献   
106.
Effects of seven organic pollutants on soil nematode Caenorhabditis elegans   总被引:1,自引:0,他引:1  
Caenorhabditis elegans is a free-living soil nematode that is commonly used as a model for toxicity tests. The aim of this study was to investigate the toxicity of seven organic pollutants: four azaarenes (quinoline, acridine, phenazine, and 1,10-phenanthroline), short-chain chlorinated paraffins, and two organochlorinated pesticides (toxaphene and hexachlorobenzene). The exposure to all chemicals was carried out in three test media (soil, agar, and aquatic medium), and adult mortality was evaluated after 24 and 48 h. Toxaphene was the most toxic substance with LC(50) (48 h) of 379 mg/kg in the soil and 0.2 mg/L in the aquatic medium. Quinoline was the most toxic chemical in agar test with LC(50) (48 h) of 10 mg/L. HCB showed a very low toxicity in all tests, maybe due to its very low water solubility. Longer than 24-h test duration was found necessary for getting more correct data on toxicity. In comparison with other studies, C. elegans was less sensitive than other soil invertebrates. Different response might be attributed to different exposure routes and shorter test duration. Equilibrium partitioning theory was used to calculate K(oc) from results of soil and aquatic tests but this approach was found not working. Our results suggest that the tests with nematode C. elegans should be included to the battery of tests for risk assessment of POPs in soil.  相似文献   
107.
Environmental Science and Pollution Research - The provision of effective sanitation strategies has a significant impact on public health. However, the treatment of septic sludge still presents...  相似文献   
108.

Bacteria from the genus Shewanella are inhabitants of marine and freshwater ecosystems, recognized fish spoilage bacteria, but less known as fish disease agents. Shewanella spp. isolated from fish living in waters close to effluents of a wastewater treatment plant (WWTP) were not previously characterized. We have tested Shewanella isolates from WWTP-affected waters and related fish. Genotypic characterization identified most strains as S. baltica and S. oneidensis. In order to investigate the sensibility and accuracy of their MALDI-TOF MS identification, they were grown on two culture media enriched by various NaCl concentrations, incubated at different temperatures and duration. We analyzed their antimicrobial susceptibility on a panel of antimicrobial drugs and capacity for biofilm production. With a view to demonstrate their capacity to produce fatty acids, we assessed the impact of different culture media on their lipid profile. We performed zebrafish embryotoxicity tests to simulate the environmental infection of the earliest life stages in S. baltica-contaminated waters. The best MALDI-TOF MS identification scores were for strains cultivated on TSA for 24 h at 22 °C and with supplementation of 1.5% NaCl. Less than 17% of isolates demonstrated antimicrobial resistance. Most isolates were weak biofilm producers. Strain-to-strain variation of MIC and MBC was low. The major fatty acids were C15:0, C16:0, C16:1, C17:1, and iC15:0. Exposure of Danio rerio to different S. baltica concentrations induced severe effects on zebrafish development: decreased heartbeat rate, locomotor activity, and melanin pigmentation. S. baltica passed through chorionic pores of zebrafish.

  相似文献   
109.
The unlimited economic growth that fuels capitalism's metabolism has profoundly transformed a large portion of Earth. The resulting environmental destruction has led to an unprecedented rate of biodiversity loss. Following large-scale losses of habitats and species, it was recognized that biodiversity is crucial to maintaining functional ecosystems. We sought to continue the debate on the contradictions between economic growth and biodiversity in the conservation science literature and thus invite scholars to engage in reversing the biodiversity crisis through acknowledging the impacts of economic growth. In the 1970s, a global agenda was set to develop different milestones related to sustainable development, including green–blue economic growth, which despite not specifically addressing biodiversity reinforced the idea that economic development based on profit is compatible with the planet's ecology. Only after biodiversity loss captured the attention of environmental sciences researchers in the early 2000s was a global biodiversity agenda implemented. The agenda highlights biodiversity conservation as a major international challenge and recognizes that the main drivers of biodiversity loss derive from economic activities. The post-2000 biodiversity agendas, including the 2030 Agenda for Sustainable Development and the post-2020 Convention on Biological Diversity Global Strategy Framework, do not consider the negative impacts of growth-oriented strategies on biodiversity. As a result, global biodiversity conservation priorities are governed by the economic value of biodiversity and its assumed contribution to people's welfare. A large body of empirical evidence shows that unlimited economic growth is the main driver of biodiversity loss in the Anthropocene; thus, we strongly argue for sustainable degrowth and a fundamental shift in societal values. An equitable downscaling of the physical economy can improve ecological conditions, thus reducing biodiversity loss and consequently enhancing human well-being.  相似文献   
110.
截至目前,环境中抗生素的行为及其对生态毒性的影响仍被忽视。这一课题的范畴是宽泛的,涉及到广泛的生物体,包括栖居在各种水生生态系统中的微生物,藻类,无脊椎动物和脊椎动物等。改变这种系统中任何一个组成的平衡破坏了整个系统的平衡。在人类和动物医学中,氟喹诺酮的制造和频繁使用引起了对微生物抗生素耐药性流行率增加的高度关注,而且,除此之外,通过各种途径进入环境生态系统的抗生素母体和代谢物化合物的归趋也引起了环境影响关注。相关研究集中在分析环境样品中氟喹诺酮的存留浓度,并且经常使用动物评估模型来测试急性毒性,但是仍然不清楚在水生环境中低水平慢性接触对生命形态的生态毒性影响中起什么作用。本综述的目的是评估氟喹诺酮在动物和人类医学中的使用水平,确定其传播的途径,突出在淡水环境中的生态毒理学影。
精选自Nicol Janecko, Lucie Pokludova, Jana Blahova, Zdenka Svobodova, Ivan Literak. Implications of fluoroquinolone contamination on the fresh water aquatic environment -A review. Environmental Toxicology and Chemistry: Volume 35, Issue 11, pages 2647–2656, November 2016. DOI: 10.1002/etc.3552
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3552/full
  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