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   30篇
  免费   1篇
  国内免费   1篇
安全科学   7篇
废物处理   1篇
环保管理   3篇
综合类   7篇
基础理论   4篇
污染及防治   2篇
评价与监测   3篇
社会与环境   5篇
  2023年   1篇
  2021年   3篇
  2020年   1篇
  2019年   2篇
  2018年   1篇
  2017年   1篇
  2016年   4篇
  2013年   1篇
  2012年   1篇
  2011年   2篇
  2010年   1篇
  2009年   1篇
  2008年   3篇
  2007年   1篇
  2005年   1篇
  2003年   1篇
  2002年   4篇
  1996年   1篇
  1972年   1篇
  1964年   1篇
排序方式: 共有32条查询结果,搜索用时 15 毫秒
11.
Human activities are continuously expanding at a global scale and having an increasing effect on the remaining natural ecosystems in remote areas, such as the Magellan Region of southern Patagonia, Chile. In addition to extensive livestock holdings, aquaculture and tourism are advancing into formerly undisturbed areas, and insufficient information on the spatial scope and intensity of these alterations is available to inform and support conservation policies. The aim of this study was to spatially analyse the degree, scope and spatial distribution of anthropogenic alterations. Accordingly, two spatially explicit indexes, the degree of anthropogenic alteration (DAA) and human influence index (HII), have been applied. The results show a significant spatial overestimation of the remaining undisturbed natural areas. Despite low population densities and extensive conservation designations, a major share of the total area has been anthropogenically altered. Depending on the measure type, between 53.1 % (DAA) and 68.1 % of the area (HII) needs to be considered as influenced by human activity in some way. Our findings challenge previous studies by the Wildlife Conservation Society (WCS and CIESIN in Last of the wild project, version 2, 2005 (LWP-2): last of the wild dataset (Geographic), NASA socioeconomic data and applications center (SEDAC), Palisades, 2005). Their worldwide assessment of pristine natural environments indicated that a much smaller part of the Magellan region has been subject to human influence. The chosen methodologies represent an opportunity to detect and monitor human influence at small spatial scales, which has heretofore remained unnoticed. Because such alterations are becoming more frequent in remote regions, the assessment approaches presented here provide important information on human–environment interactions to support land-use and nature conservation policy design. In addition, small-scale structures and different types of economic activities are considered to support policies that can protect the remaining natural areas from human encroachment. Moreover, implications of the proposed methodology for biodiversity conservation policy are discussed.  相似文献   
12.
Humans have always played a crucial role in the evolutionary dynamics of agricultural biodiversity and thus there is a strong relationship between these resources and human cultures. These agricultural resources have long been treated as a global public good, and constitute the livelihoods of millions of predominantly poor people. At the same time, agricultural biodiversity is under serious threat in many parts of the world despite extensive conservation efforts. Ethical considerations regarding the collecting, research, and use of agricultural biodiversity are currently topics of great concern. For example, easy access to genetic resources for breeding purposes is important, but international agreements and legal frameworks are necessary to ensure adequate recognition of the contributions of local communities and traditional farmers in creating and nurturing these resources. Here, we assess ethical principles in the context of existing codes of conduct that are relevant for agro-biodiversity researchers. We aim to create awareness among scientists and policy makers who are concerned with agro-biodiversity research and its potential impact on local communities. We encourage a serious assessment of the ethical principles presented here and hope to facilitate an integration of these principles into the reader’s personal ethical framework. Key ethical principles considered here include the importance of obtaining prior informed consent, equity, and the inalienability of rights of local communities and farmers.  相似文献   
13.
Industrialized countries agreed on a reduction of greenhouse gas emissions under the Kyoto Protocol. Many countries elected forest management activities and the resulting net balance of carbon emissions and removals of non-CO2 greenhouse gases by forest management in their climate change mitigation measures. In this paper a generic dynamic forestry model (FORMICA) is presented. It has an empirical basis. Several modules trace C pools relevant for the Kyoto Protocol and beyond: biomass, litter, deadwood and soil, and harvested wood products. The model also accounts for the substitution of fossil fuels by wood products and bioenergy.  相似文献   
14.
Pseudomonas spp. is a group of microorganisms commonly found in fish and other fresh foods and is involved in their spoilage process. The aim of this study was to develop a rapid and accurate quantitative assay for Pseudomonas spp. in fish using real-time PCR. The assay targets the carbamoyl phosphate synthase gene (carA) with SYBR green based real-time PCR. The selectivity of the assay was confirmed using 24 Pseudomonas strains and 55 non-pseudomonad strains. A linear quantification was established over seven orders of magnitude, from 40 - 4(7) copies reaction(-1). The assay was validated on cod samples collected during two shelf life trials and showed a high degree of correlation to the plate count method (rP = 0.891) where the difference between the methods was 0.04 log(10) CFU g(-1) on average. The study shows that it is possible to quantify accurately the specific spoilage organisms belonging to the genus Pseudomonas in fish using real-time PCR. The method takes less than 5 h from sampling to results. The short detection time of the method can provide the fish industry with an important tool for quality control and processing management.  相似文献   
15.
The increasing number of nanomaterial based consumer products raises concerns about their possible impact on the environment. This study provides an assessment of the effluent from a commercially available silver nanowashing machine. The washing machine released silver in its effluent at an average concentration of 11μgL(-1), as determined by inductive coupled mass spectrometry (ICP-MS). The presence of silver nanoparticles (AgNPs) was confirmed by single particle ICP-MS as well as ion selective electrode measurements and filtration techniques. Size measurements showed particles to be in the defined nanosize range, with an average size of 10nm measured with transmission electron microscopy (TEM) and 60-100nm determined with nanoparticle tracking analysis (NTA). The effluent was shown to have negative effects on a natural bacterial community as its abundance was clearly reduced when exposed to the nanowash water. If washing machines capable of producing AgNPs become a common feature of households in the future, wastewater will contain significant loadings of AgNPs which might be released into the environment.  相似文献   
16.
Environmental threats and progressive degradation of natural resources are considered critical impediments to sustainable development. This paper reports on a participatory impact assessment of alternative soil and water conservation (SWC) scenarios in the Oum Zessar watershed, Tunisia. The first objective was to assess the impact of three SWC scenarios on key social, economic and environmental land use functions. The second objective was to test and evaluate the applicability of the 'Framework for Participatory Impact Assessment (FoPIA)' for assessing scenario impacts in the context of a developing country, in this case Tunisia. The assessed scenarios included: the originally planned SWC policy implementation at 85 % coverage of arable land of the watershed, the current implementation (70 %), and a hypothetical expansion of SWC measures to the entire watershed (100 %). Our results suggest that implementation of the SWC policy at 100 % coverage of arable land achieves the maximum socioeconomic benefit. However, if stakeholders' preferences regarding land use functions are taken into account, and considering the fact that the implementation of SWC measures also implies some negative changes to traditional landscapes and the natural system, SWC implementation at 85 % coverage of arable land might be preferable. The FoPIA approved to be a useful tool for conducting a holistic sustainability impact assessment of SWC scenarios and for studying the most intriguing sustainability problems while providing possible recommendations towards sustainable development. We conclude that participatory impact assessment contributes to an enhanced regional understanding of key linkages between policy effects and sustainable development, which provides the foundation for improved policy decision making.  相似文献   
17.

Phosphorus rich sewage sludge ash is a promising source to produce phosphorus recycling fertilizer. However, the low plant availability of phosphorus in these ashes makes a treatment necessary. A thermochemical treatment (800–1000 °C) with alkali additives transforms poorly plant available phosphorus phases to highly plant available calcium alkali phosphates (Ca,Mg)(Na,K)PO4. In this study, we investigate the use of K2SO4 as additive to produce a phosphorus potassium fertilizer in laboratory-scale experiments (crucible). Pure K2SO4 is not suitable as high reaction temperatures are required due to the high melting point of K2SO4. To overcome this barrier, we carried out series of experiments with mixtures of K2SO4 and Na2SO4 resulting in a lower economically feasible reaction temperature (900–1000 °C). In this way, the produced phosphorus potassium fertilizers (8.4 wt.% K, 7.6 wt.% P) was highly plant available for phosphorus indicated by complete extractable phosphorus in neutral ammonium citrate solution. The added potassium is, in contrast to sodium, preferably incorporated into silicates instead of phosphorus phases. Thus, the highly extractable phase (Ca,Mg)(Na,K)PO4 in the thermochemical products contain less potassium than expected. This preferred incorporation is confirmed by a pilot-scale trial (rotary kiln) and thermodynamic calculation.

  相似文献   
18.
19.
We report on a case of gastroschisis in which sudden dilatation of extra-abdominal bowel at 34+1 weeks was followed by an unusual umbilical flow velocity waveform (diastolic notching). The condition was associated with normal umbilical Doppler indices, brain sparing effect and a non-reactive cardiotocograph (CTG). Findings at postnatal surgery strongly suggested severe cord compression by the herniated dilated bowel. The significance of notching in the umbilical artery waveform is discussed, as is the potential importance of this sign in the prepartum management of fetuses with gastroschisis. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
20.
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