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   64篇
  免费   1篇
安全科学   12篇
废物处理   2篇
环保管理   2篇
综合类   14篇
基础理论   7篇
污染及防治   19篇
评价与监测   7篇
社会与环境   2篇
  2023年   1篇
  2022年   1篇
  2021年   1篇
  2020年   2篇
  2019年   1篇
  2018年   4篇
  2017年   4篇
  2016年   3篇
  2015年   1篇
  2014年   3篇
  2013年   5篇
  2012年   7篇
  2011年   3篇
  2010年   6篇
  2009年   3篇
  2008年   6篇
  2007年   3篇
  2006年   2篇
  2005年   1篇
  2003年   1篇
  2001年   1篇
  1995年   1篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1985年   1篇
排序方式: 共有65条查询结果,搜索用时 31 毫秒
41.
The water footprint by the Water Footprint Network (WF) is an ambitious tool for measuring human appropriation and promoting sustainable use of fresh water. Using recent case studies and examples from water-abundant Fennoscandia, we consider whether it is an appropriate tool for evaluating the water use of forestry and forest-based products. We show that aggregating catchment level water consumption over a product life cycle does not consider fresh water as a renewable resource and is inconsistent with the principles of the hydrologic cycle. Currently, the WF assumes that all evapotranspiration (ET) from forests is a human appropriation of water although ET from managed forests in Fennoscandia is indistinguishable from that of unmanaged forests. We suggest that ET should not be included in the water footprint of rain-fed forestry and forest-based products. Tools for sustainable water management should always contextualize water use and water impacts with local water availability and environmental sensitivity.  相似文献   
42.
Molecular profiling methods for horizontal transfer of aromatics-degrading plasmids were developed and applied during rhizoremediation in vivo and conjugations in vitro. pWW0 was conjugated from Pseudomonas to Rhizobium. The xylE gene was detected both in Rhizobium galegae bv. officinalis and bv. orientalis, but it was neither stably maintained in orientalis nor functional in officinalis. TOL plasmids were a major group of catabolic plasmids among the bacterial strains isolated from the oil-contaminated rhizosphere of Galega orientalis. A new finding was that some Pseudomonas migulae and Pseudomonas oryzihabitans strains harbored a TOL plasmid with both pWW0- and pDK1-type xylE gene. P. oryzihabitans 29 had received the archetypal TOL plasmid pWW0 from Pseudomonas putida PaW85. As an application for environmental biotechnology, the biodegradation potential of oil-polluted soil and the success of bioremediation could be estimated by monitoring changes not only in the type and amount but also in transfer of degradation plasmids.  相似文献   
43.
Two silver birch clones were exposed to ambient and elevated concentrations of CO2 and O3, and their combination for 3 years, using open-top chambers. We evaluated the effects of elevated CO2 and O3 on stomatal conductance (gs), density (SD) and index (SI), length of the guard cells, and epidermal cell size and number, with respect to crown position and leaf type. The relationship between the infection biology of the fungus (Pyrenopeziza betulicola) causing leaf spot disease and stomatal characteristics was also studied. Leaf type was an important determinant of O3 response in silver birch, while crown position and clone played only a minor role. Elevated CO2 reduced the gs, but had otherwise no significant effect on the parameters studied. No significant interactions between elevated CO2 and O3 were found. The infection biology of P. betulicola was not correlated with SD or gs, but it did occasionally correlate positively with the length of the guard cells.  相似文献   
44.
On-site sanitation is increasingly adopted in urban cities in India. The adoption of On-site sanitation system puts the groundwater resources in the vicinity of the system at a greater risk. Microbial contaminants as well as chemical contaminants like Chloride and Nitrate are generated from human waste. These contaminants travel through the medium and ultimately get in contact with the groundwater. Hence, the groundwater sources are vulnerable to nitrate contamination near the On-site sanitation systems. The present study indicates significant Nitrate and Chloride contamination in samples collected close to On-site sanitation systems. The recommended limit set by the Bureau of Indian standards (BIS) limit of 45 mg/l for Nitrate concentration is also exceeded in few samples. The study indicates that Bacterial as well as Nitrate contamination is more in Monsoon as compared to Summer.  相似文献   
45.
Recently, computer, mobile phone and Internet use has increased. This study aimed to determine the possible relation between self-reported wrist and finger symptoms (aches, pain or numbness) and using computers/mobile phones, and to analyze how the symptoms are specifically associated with utilizing desktop computers, portable computers or mini-computers and mobile phones. A questionnaire was sent to 15,000 working-age Finns (age 18–65). Via a questionnaire, 723 persons reported wrist and finger symptoms often or more with use. Over 80% use mobile phones daily and less than 30% use desktop computers or the Internet daily at leisure, e.g., over 89.8% quite often or often experienced pain, numbness or aches in the neck, and 61.3% had aches in the hips and the lower back. Only 33.7% connected their symptoms to computer use. In the future, the development of new devices and Internet services should incorporate the ergonomics of the hands and wrists.  相似文献   
46.
We investigated penetration patterns of monomeric and polymeric 1,6-hexamethylene diisocyanate (HDI), experimentally and as part of commercial products, in excised full-thickness human skin at 5, 10, 30, or 60 min after exposure. We observed that both monomeric and polymeric HDI were readily absorbed into the skin and that the clearcoat composition affects the penetration rate of the individual isocyanates. The short-term absorption rates for HDI monomer, biuret, and isocyanurate were determined and used to estimate the exposure time required to reach a body burden equal to the American Conference of Governmental Industrial Hygienists (ACGIH) inhalation threshold limit value (TLV) or Oregon State occupational exposure limit (OEL). Oregon is the only government entity in the United States to promulgate a short-term exposure limit (STEL) for HDI-based polyisocyanates biuret and isocyanurate. Based on these absorption rates for a slow-drying clearcoat after 10 min (1.33 μg cm(-2) h(-1)) or 60 min (0.219 μg cm(-2) h(-1)), we calculated that 6.5 and 40 min dermal exposure, respectively, is required to achieve a dose of HDI equivalent to the ACGIH TLV. For biuret, the time to achieve a dose equivalent to the Oregon OEL for slow-drying clearcoat was much shorter (<31 min) than that for fast-drying clearcoat (618 min). Isocyanurate had the shortest skin absorption times regardless of clearcoat formulation (14 s-1.7 min). These results indicate that the dose received through dermal exposure to HDI-containing clearcoats has a significant potential to exceed the dose equivalent to that received through inhalation exposure at established regulatory limits. A critical need exists to monitor dermal exposure quantitatively in exposed workers, to use proper protective equipment to reduce dermal exposure, and to re-evaluate regulatory exposure limits for isocyanates.  相似文献   
47.
Respiratory sensitization and occupational asthma are associated with exposure to 1,6-hexamethylene diisocyanate (HDI) in both monomeric and oligomeric forms. The monomer and polymers of diisocyanates differ significantly in their rates of absorption into tissue and their toxicity, and hence may differ in their contribution to sensitization. We have developed and evaluated a liquid chromatography/mass spectrometry (LC-MS) method capable of quantifying HDI and its oligomers (uretidone, biuret, and isocyanurate) in air, tape-stripped skin, and paint samples collected in the automotive refinishing industry. To generate analytical standards, urea derivatives of HDI, biuret, and isocyanurate were synthesized by reaction with 1-(2-methoxyphenyl)piperazine and purified. The urea derivatives were shown to degrade on average by less than 2% per week at -20 degrees C over a 2 month period in occupational samples. The average recovery of HDI and its oligomers from tape was 100% and the limits of detection were 2 and 8 fmol microl(-1), respectively. Exposure assessments were performed on 13 automotive spray painters to evaluate the LC-MS method and the sampling methods under field conditions. Isocyanurate was the most abundant component measured in paint tasks, with median air and skin concentrations of 2.4 mg m(-3) and 4.6 microg mm(-3), respectively. Log-transformed concentrations of HDI (r = 0.79, p < 0.0001) and of isocyanurate (r = 0.71, p < 0.0001) in the skin of workers were correlated with the log-transformed product of air concentration and painting time. The other polyisocyanates were detected on skin for less than 25% of the paint tasks. This LC-MS method provides a valuable tool to investigate inhalation and dermal exposures to specific polyisocyanates and to explore relative differences in the exposure pathways.  相似文献   
48.
Drained peatlands are an important source of forest biomass in boreal regions and ditch network maintenance (DNM) operations may be needed to restore the drainage functions of ditches. By reviewing the available literature, as well as utilizing an existing hydrological model and analyzing the characteristics of eroded sediments, we assessed the impacts of DNM on runoff and exports of suspended solids (SS), dissolved organic carbon (DOC), nitrogen (N), and phosphorus (P). In general, DNM had minor impact on runoff and dissolved N and P, and it decreased rather than increased DOC exports. To increase the understanding of the hydrochemical impacts of DNM, future research should focus on the characteristics of SS and particulate nutrient exports. A major gap in knowledge is also the very limited regional representativeness of the available studies. High erosion risk in the ditches reaching the mineral soil below peat should be acknowledged when planning mitigation measures.  相似文献   
49.
The number of collaborative initiatives between scientists and volunteers (i.e., citizen science) is increasing across many research fields. The promise of societal transformation together with scientific breakthroughs contributes to the current popularity of citizen science (CS) in the policy domain. We examined the transformative capacity of citizen science in particular learning through environmental CS as conservation tool. We reviewed the CS and social‐learning literature and examined 14 conservation projects across Europe that involved collaborative CS. We also developed a template that can be used to explore learning arrangements (i.e., learning events and materials) in CS projects and to explain how the desired outcomes can be achieved through CS learning. We found that recent studies aiming to define CS for analytical purposes often fail to improve the conceptual clarity of CS; CS programs may have transformative potential, especially for the development of individual skills, but such transformation is not necessarily occurring at the organizational and institutional levels; empirical evidence on simple learning outcomes, but the assertion of transformative effects of CS learning is often based on assumptions rather than empirical observation; and it is unanimous that learning in CS is considered important, but in practice it often goes unreported or unevaluated. In conclusion, we point to the need for reliable and transparent measurement of transformative effects for democratization of knowledge production.  相似文献   
50.
Characteristics and formation of leachates from waste gasification and grate firing bottom ash were studied using continuous field measurements from 112 m3 lysimeters embedded into landfill body for three years. In addition, the total element concentrations of the fresh ash were analysed and laboratory batch tests were performed to study leachate composition. The three-year continuous flow measurement showed that about one fifth of the leachates were formed, when the flow rate was >200 l/d, covering <3.5% of the study time. After three years, the liquid/solid-ratio for the quenched grate ash was 1 (l/kg (d.m.)) and for the initially dry gasification ash 0.4 (l/kg (d.m.)). The low initial water and residual carbon content of the gasification ash kept the leachate pH at a high level (>13) major part of the study. In the grate ash leachate pH was lower (<8) due to the presence of organic carbon and biodegradation indicated by biological oxygen demand and redox potential measurements. In the gasification ash the high pH probably delayed leaching of major elements such as Ca, therefore, raising the need for a longer after-care period. The high pH also explains the higher leaching of As from the gasification ash compared to the grate ash both in the batch test and under landfill conditions.  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