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   37篇
  免费   0篇
环保管理   6篇
综合类   11篇
基础理论   10篇
环境理论   1篇
污染及防治   5篇
评价与监测   2篇
社会与环境   2篇
  2022年   2篇
  2018年   3篇
  2016年   1篇
  2015年   1篇
  2014年   2篇
  2013年   2篇
  2012年   4篇
  2011年   2篇
  2010年   1篇
  2009年   1篇
  2008年   2篇
  2007年   2篇
  2006年   1篇
  2005年   1篇
  2004年   1篇
  2002年   1篇
  2001年   2篇
  1999年   2篇
  1996年   2篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1983年   1篇
排序方式: 共有37条查询结果,搜索用时 0 毫秒
11.
12.
A method is presented for estimating the global warming impact of forest biomass life cycles with respect to their functionally equivalent alternatives based on fossil fuels and non-renewable material sources. In the method, absolute global warming potentials (AGWP) of both the temporary carbon (C) debt of forest biomass stock and the C credit of the biomass use cycle displacing the fossil and non-renewable alternative are estimated as a function of the time frame of climate change mitigation. Dimensionless global warming potential (GWP) factors, GWPbio and GWPbiouse, are derived. As numerical examples, 1) bioenergy from boreal forest harvest residues to displace fossil fuels and 2) the use of wood for material substitution are considered. The GWP-based indicator leads to longer payback times, i.e. the time frame needed for the biomass option to be superior to its fossil-based alternative, than when just the cumulative balance of biogenic and fossil C stocks is considered. The warming payback time increases substantially with the residue diameter and low displacement factor (DF) of fossil C emissions. For the 35-cm stumps, the payback time appears to be more than 100 years in the climate conditions of Southern Finland when DF is lower than 0.5 in instant use and lower than 0.6 in continuous stump use. Wood use for construction appears to be more beneficial because, in addition to displaced emissions due to by-product bioenergy and material substitution, a significant part of round wood is sequestered into wood products for a long period, and even a zero payback time would be attainable with reasonable DFs.  相似文献   
13.
The reduction of carbon dioxide (CO2) emissions may be quite expensive and it is necessary to consider reduction measures for other anthropogenic greenhouse gases, such as methane (CH4) and nitrous oxide (N2O) as well. Their contribution to the total GHG emission from Finland is about 15–20%. In Finland most of the CH4 emissions are due to waste management, agriculture and burning processes. N2O emissions originate from burning processes, agriculture, industry and atmospheric deposition of nitrogen. The cost-effective reduction of the Finnish GHG emissions has been studied with the EFOM-ENV model, which is a quasi-dynamic linear energy system optimisation model. The target function to be minimised is the total discounted cost for the modelled system. In this study the model has been expanded to cover all well-known anthropogenic CO2, CH4 and N2O sources and reduction measures. The results indicate it is economic to reduce the emissions of CO2, CH4 and N2O in Finland. It is profitable to exploit the economic reduction potential of CH4 and N2O, because then the abatement of CO2 emissions does not need to be as extensive as when the reduction is aimed only at CO2 emissions. The inclusion of CH4 and N2O decreases the annual reduction costs about 20% in the year 2010.  相似文献   
14.
Habitat Loss,the Dynamics of Biodiversity,and a Perspective on Conservation   总被引:1,自引:0,他引:1  
Hanski I 《Ambio》2011,40(3):248-255
  相似文献   
15.
The raw water quality and associations between the factors considered as threats to water safety were studied in 20 groundwater supplies in central Finland in 2002-2004. Faecal contaminations indicated by the appearance of Escherichia coli or intestinal enterococci were present in five small community water supplies, all these managed by local water cooperatives. Elevated concentrations of nutrients in raw water were linked with the presence of faecal bacteria. The presence of on-site technical hazards to water safety, such as inadequate well construction and maintenance enabling surface water to enter into the well and the insufficient depth of protective soil layers above the groundwater table, showed the vulnerability of the quality of groundwater used for drinking purposes. To minimize the risk of waterborne illnesses, the vulnerable water supplies need to be identified and appropriate prevention measures such as disinfection should be applied.  相似文献   
16.
The achievement possibilities of the EU 2 °C climate target have been assessed with the ETSAP TIAM global energy systems model. Cost-effective global and regional mitigation scenarios of carbon dioxide, methane, nitrous oxide and F-gases were calculated with alternative assumptions on emissions trading. In the mitigation scenarios, an 85% reduction in CO2 emissions is needed from the baseline, and very significant changes in the energy system towards emission-free sources take place during this century. The largest new technology groups are carbon-capture and storage (CCS), nuclear power, wind power, advanced bioenergy technologies and energy efficiency measures. CCS technologies contributed a 5.5-Pg CO2 annual emission reduction by 2050 and 12 Pg CO2 reduction by 2100. Also large-scale forestation measures were found cost-efficient. Forestation measures reached their maximum impact of 7.7 Pg CO2 annual emission reduction in 2080. The effects of uncertainties in the climate sensitivity have been analysed with stochastic scenarios.  相似文献   
17.
18.
Microbiological contamination of groundwater supplies causes waterborne outbreaks worldwide. In this study, two waterborne outbreaks related to microbiological contamination of groundwater supplies are described. Analyses of pathogenic human enteric viruses (noroviruses and adenoviruses), fecal bacteria (Campylobacter spp. and Salmonella spp.), and indicator microbes (E. coli, coliform bacteria, intestinal enterococci, Clostridium perfringens, heterotrophic plate count, somatic and F-specific coliphages) were conducted in order to reveal the cause of the outbreaks and to examine the effectiveness of the implemented management measures. Moreover, the long-term persistence of noro- and adenovirus genomes was investigated. Noroviruses were detected in water samples from both outbreaks after the intrusion of wastewater into the drinking water sources. In the outbreak I, the removal efficiency of norovirus genome (3.0 log10 removal) in the sand filter of onsite wastewater treatment system (OWTS) and during the transport through the soil into the groundwater well was lower than the removal efficiencies of E. coli, coliform bacteria, intestinal enterococci, and spores of C. perfringens (6.2, 6.0, > 5.9, and > 4.8 log10 removals, respectively). In the outbreak II, cleaning of massively contaminated groundwater well and drinking water distribution network proved challenging, and noro- and adenovirus genomes were detected up to 3 months (108 days). The long-term persistence study showed that noro- and adenovirus genomes can remain detectable in the contaminated water samples up to 1277 and 1343 days, respectively. This study highlights the transport and survival properties of enteric viruses in the environment explaining their potency to cause waterborne outbreaks.  相似文献   
19.
Immobilization: A Revolution in Traditional Brewing   总被引:1,自引:0,他引:1  
  相似文献   
20.
Cartilage-hair hypoplasia (CHH) is an autosomal recessive disorder resulting in short stature and hypoplasia of hair. Associated features include impaired T-cell-mediated immunity, deficient erythropoiesis, gastrointestinal dysfunction, and an increased risk of malignancies. As the condition may, in some cases, be severe or even fatal during childhood, families with a previous history of CHH may wish to have prenatal diagnosis. We have previously assigned the gene for CHH to the proximal 9p by linkage analysis using several polymorphic DNA markers. Here we report the prenatal testing for CHH in three Finnish and one Australian family using three DNA markers closely linked to the CHH gene. In three cases a fetus unaffected with CHH was predicted at the probability level of more than 94 per cent. In one case, an affected fetus was predicted. The results were in concordance with ultrasonography performed for all fetuses. The three children born to date were unaffected as predicted. The DNA marker-based analysis thus provides a useful method for early prenatal testing for CHH.  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