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   104篇
  免费   0篇
  国内免费   3篇
安全科学   4篇
废物处理   3篇
环保管理   3篇
综合类   18篇
基础理论   34篇
污染及防治   32篇
评价与监测   4篇
社会与环境   8篇
灾害及防治   1篇
  2021年   4篇
  2019年   4篇
  2018年   3篇
  2017年   5篇
  2016年   4篇
  2015年   9篇
  2014年   8篇
  2013年   9篇
  2012年   5篇
  2011年   9篇
  2010年   5篇
  2009年   5篇
  2008年   4篇
  2007年   4篇
  2006年   6篇
  2005年   6篇
  2004年   2篇
  2003年   4篇
  2002年   1篇
  2001年   2篇
  2000年   4篇
  1999年   1篇
  1998年   1篇
  1996年   1篇
  1995年   1篇
排序方式: 共有107条查询结果,搜索用时 15 毫秒
81.
The sustainable management of chemicals and their associated wastes—especially legacy stockpiles—is always challenging. Developing countries face particular difficulties as they often have insufficient treatment and disposal capacity, have limited resources and many lack an appropriate and effective regulatory framework. This paper describes the objectives and the approach of the Egyptian–German Twinning Project under the European Neighbourhood Policy to improve the strategy of managing hazardous substances in the Egyptian Environmental Affairs Agency (EEAA) between November 2008 and May 2011. It also provides an introduction to the Republic of Egypt’s legal and administrative system regarding chemical controls. Subsequently, options for a new chemical management strategy consistent with the recommendations of the United Nations Chemicals Conventions are proposed. The Egyptian legal and administrative system is discussed in relation to the United Nations’ recommendations and current European Union legislation for the sound management of chemicals. We also discuss a strategy for the EEAA to use the existing Egyptian legal system to implement the United Nations’ Globally Harmonized System of Classification and Labelling of Chemicals, the Stockholm Convention and other proposed regulatory frameworks. The analysis, the results, and the recommendations presented may be useful for other developing countries in a comparable position to Egypt aspiring to update their legislation and administration to the international standards of sound management of chemicals.  相似文献   
82.
Environmental pollution by mercury (Hg) is a considerable environmental problem world-wide. Due to the occurrence of Hg volatilization from their soils, floodplains can function as an important source of volatile Hg. Soil temperature and soil water content related to flood dynamics are considered as important factors affecting seasonal dynamics of total gaseous mercury (TGM) fluxes. We quantified seasonal variations of TGM fluxes and conducted a laboratory microcosm experiment to assess the effect of temperature and moisture on TGM fluxes in heavily polluted floodplain soils. Observed TGM emissions ranged from 10 to 850 ng m−2 h−1 and extremely exceeded the emissions of non-polluted sites. TGM emissions increased exponentially with raised air and soil temperatures in both field (R2: 0.49-0.70) and laboratory (R2: 0.99) experiments. Wet soil material showed higher TGM fluxes, whereas the role of soil water content was affected by sampling time during the microcosm experiments.  相似文献   
83.
When discussing strategies for realising an environmental friendly agricultural production, there are methods for quantifying environmental effects which do not originate in agricultural contexts. For instance, the methodology of Life Cycle Assessment is mainly developed from analyses of industrial production lines and products. Substance flow analyses in agriculture contain a complete analysis of agriculturally caused substance and energy flows, to which certain environmental effects are assigned, and also an assessment of these effects. For the provision of production means, balancing agricultural production procedures includes the extraction of energy sources and mineral resources from their reservoirs. The growth phase of the crops regarded (cereals, sugar beet, rape) is described depending on the nutrients nitrogen, phophor, potassium and calcium. The nitrogen flux within the system plant-soil-atmosphere is recorded referring to its temporal dynamic. In the framework of this study, selected environmental effects of agricultural production procedures of winter wheat are calculated regarding different conditions of locations and are supplemented by declining scenario simulations. Essential features of the structure of the substance flow net, which is implemented for the calculation and which can be used completely or as for single modules for further studies, are explained. Basing on selected categories of effectiveness, ecological optimisation potentials of varying agricultural provision of production means and procedures are estimated within the whole context of provision. Thereby, the effects of a reduced employment of fertilisers, of a change as for the kind of fertiliser and of the region of origin of the N-fertiliser, as well as variations concerning mechanical work in the fields are outlined for the cultivation of winter wheat.  相似文献   
84.
Objective. Surgical nurses’ work is physically and mentally demanding, possibly leading to work–family conflict (WFC). The current study tests WFC to be a risk factor for neck and lower back pain (LBP). Job influence and social support are tested as resources that could buffer the detrimental impact of WFC. Methods. Forty-eight surgical nurses from two university hospitals in Germany and Switzerland were recruited. WFC was assessed with the Work–Family Conflict Scale. Job influence and social support were assessed with the Copenhagen Psychosocial Questionnaire, and back pain was assessed with the North American Spine Society Instrument. Results. Multiple linear regression analyses confirmed WFC as a significant predictor of cervical pain (β?=?0.45, p?β?=?0.33, p?=?0.012). Job influence and social support did not turn out to be significant predictors and were not found to buffer the impact of WFC in moderator analyses. Conclusion. WFC is likely to affect neck and back pain in surgery nurses. Work–life interventions may have the potential to reduce WFC in surgery nurses.  相似文献   
85.
86.
Current conservation templates prioritize biogeographic regions with high intensity ecosystem values, such as exceptional species richness or threat. Intensity-based targets are an important consideration in global efforts, but they do not capture all available opportunities to conserve ecosystem values, including those that accrue in low intensity over large areas. We assess six globally-significant ecosystem values—intact wilderness, freshwater availability, productive marine environments, breeding habitat for migratory wildlife, soil carbon storage, and latitudinal potential for range shift in the face of climate change—to highlight opportunities for high-impact broadly-distributed contributions to global conservation. Nations can serve as a cohesive block of policy that can profoundly influence conservation outcomes. Contributions to global ecosystem values that exceed what is predicted by a nation's area alone, can give rise to countries with the capacity to act as ‘conservation superpowers’, such as Canada and Russia. For these conservation superpowers, a relatively small number of national policies can have environmental repercussions for the rest of the world.  相似文献   
87.
This study investigates the influence of the two different clay minerals kaolinite and smectite as well as of organic matter on the cation sorption and desorption behaviour of three imidazolium based ionic liquids -1-butyl-3-methyl-imidazolium tetrafluoroborate (IM14 BF(4)), 1-methyl-3-octyl-imidazolium tetrafluoroborate (IM18 BF(4)) and 1-butyl-3-methyl-imidazolium bis[(trifluoromethyl)sulfonyl]imide (IM14 (CF(3)SO(2))(2)N) - in soil. The German standard soil Lufa 2.2 - a natural soil classified as a loamy sand - was the basis substrate for the different soil compositions and also served as a reference soil. The addition of organic matter and clays increases the sorption of the substances and in particular smectite had striking effects on the sorption capacity for all three ionic liquids indicating that ionic interactions play an important role for sorption and desorption processes of ionic liquids in soil. One exception was for kaolinite-containing soils and the IM14 cation: with (CF(3)SO(2))(2)N(-) as an anion the sorption was identical at either 10 wt% or 15 wt% clay content, and with BF(4)(-) sorption was even lower at 15 wt% kaolinite than at 10 wt%. Desorption was weak for IM18 BF(4), presumably owing to the longer alkyl side chain. With regard to the influence of kaolinite on desorption, the same pattern was observed as it was found for the sorption of IM14 BF(4) and IM14 (CF(3)SO(2))(2)N.  相似文献   
88.
A survey was carried out on the activity concentrations of 210Pb and 210Po in cereal grains produced in Finland. The cereal species were wheat (Triticum aestivum), rye (Secale cereale), oats (Avena sativa) and barley (Hordeum vulgare), which account for 90% of the Finnish consumption of cereal products. The survey consisted of 18 flour and 13 unprocessed cereal samples and one hulled grain sample from 22 flour mills. According to the results, the mean 210Pb/210Po concentrations in wheat grains, wheat flour, rye flour, oat grains and barley grains were 0.29, 0.12, 0.29, 0.36 and 0.36 Bq kg−1, respectively. Combined with the consumption rates of the products, we assess that the mean effective doses from 210Pb and 210Po in cereal products for the adult male and female population are 22 and 17 μSv per year, respectively.  相似文献   
89.
Before wood ash can be used as a soil fertilizer, concentrations of environmentally hazardous compounds must be investigated. In this study, total and leachable concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in four ash samples and one green liquor sludge. The ash sample with the highest carbon content also contained high levels of PAHs; three of the ash samples had total concentrations exceeding the limit permitted by the Swedish Forest Agency for recycling to forest soils. The leachable concentrations were higher for the non-stabilized samples; this was probably due to colloid-facilitated transport of the contaminants in these samples. However, the leachable concentrations were overall relatively low in all the samples studied. The amounts of PAHs introduced to forest soils by additions of stabilized, recyclable ash products will be determined primarily by the rate of weathering of the ash particles and the total concentration of contaminants.  相似文献   
90.
An equilibrium and recirculation column test for hydrophobic organic chemicals (ER-H test) was used to study the leaching behaviour of chlorophenols (CPs), polychlorinated diphenyl ethers (PCDEs), polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) from contaminated soil. A 50% increase in the pore water velocity was shown to have little or no effect on the mobility of CPs, PCDEs, PCDFs and PCDDs. The standard deviations of truly dissolved compounds, CPs, were between 19% and 65% between the tests. However, the repeatability of the ER-H test decreased with increases in the hydrophobicity of the studied compounds; the standard deviations for PCDEs, PCDFs and PCDDs ranged from 53% to 110%, 57% to 77% and 110% to 130%, respectively. The influence of colloids on the release of these compounds was also examined. Up to 30% of the CPs in the soil were leached, of which 1-3% were associated with colloids. The PCDEs, PCDFs and PCDDs were found to be preferably associated with the particulate fraction of the leachate, and less than 0.2% of these compounds were mobilised.  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