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   67篇
  免费   1篇
  国内免费   1篇
安全科学   2篇
废物处理   5篇
环保管理   9篇
综合类   18篇
基础理论   15篇
环境理论   1篇
污染及防治   10篇
评价与监测   3篇
社会与环境   6篇
  2022年   1篇
  2021年   1篇
  2019年   5篇
  2018年   8篇
  2017年   2篇
  2016年   1篇
  2015年   3篇
  2014年   3篇
  2013年   1篇
  2012年   9篇
  2011年   6篇
  2010年   4篇
  2009年   6篇
  2008年   4篇
  2007年   5篇
  2006年   4篇
  2005年   2篇
  2004年   2篇
  1968年   1篇
  1952年   1篇
排序方式: 共有69条查询结果,搜索用时 15 毫秒
61.
This review presents first ever literature survey on historical development of farm animal welfare indicators and assessment in the Danube region. This area, encompassing European Eastern countries and the Balkans, is to a large extent heterogeneous in terms of culture and language. However, international (English) publications were disproportionally small compared to the amount of research institutions and animal welfare activities present in the region. Therefore, the authors aimed at investigating the published literature, focusing on country level and on native languages. Data were collected for the 1980–2015 period referring to scientific papers published in international and national journals, papers and abstracts in proceedings of the international and national conferences, reviews, monographs, short communications, Ph.D., Master and Graduation theses. Welfare assessment of all farm animal species was observed including fish. Over 180 papers were in line with the preselected index. Data collected showed that publishing dynamics grew rapidly towards the last decade. Most of the studies were focused on animal welfare indicators such as stress, injuries and mutilations, behaviour, body condition and management practices. Cattle, chickens, pigs and sheep were the predominant species investigated. The study revealed that experts from the region were greatly involved in the studies of animal welfare indicators and assessment, contributing to development of the currently most widely used animal welfare assessment protocols, thus having an important role in animal welfare research and protection.  相似文献   
62.
The exposure levels of placenta and paired breast milk samples to selected organochlorine compounds and pesticides from Danish and Finnish samples have been investigated. p,p'-DDE is the dominant pollutant, beta-HCH, hexachlorobenzene, endosulfan-I, dieldrin, oxychlordane, cis-heptachlor epoxide and p,p'-DDT being the other major constituents. Their concentrations are linearly correlated between milk and placenta in similar patterns for Danish and Finnish samples. Milk samples have higher levels of these pollutants than placenta on lipid base. However, the apparently not correlated compounds, such as alpha-HCH, pentachlorobenzene, pentachloroanisole and methoxychlor, are generally accumulated more in placenta, which may suggest a tissue specific metabolic activity. Thus, depending on the compound of interest, biomonitoring may be done in placenta only or in both matrices.  相似文献   
63.
64.
65.
Risk assessment of two sections (I and II) of an old landfill (ALH) in Styria (Austria) in terms of reactivity of waste organic matter and the related potential of gaseous emissions was performed using conventional parameters and innovative tools to verify their effectiveness in practice. The ecological survey of the established vegetation at the landfill surface (plant sociological relevés) indicated no relevant emissions over a longer period of time. Statistical evaluation of conventional parameters reveals that dissolved organic carbon (DOC), respiration activity (RA4), loss of ignition (LOI) and total inorganic carbon (TIC) mostly influence the variability of the gas generation sum (GS21). According to Fourier Transform Infrared (FT-IR) spectral data and the results of the classification model the reactivity potential of the investigated sections is very low which is in accordance with the results of plant sociological relevés and biological tests. The interpretation of specific regions in the FT-IR spectra was changed and adapted to material characteristics. Contrary to mechanically–biologically treated (MBT) materials, where strong aliphatic methylene bands indicate reactivity, they are rather assigned to the CH vibrations of plastics in old landfill materials. This assumption was confirmed by thermal analysis and the characteristic heat flow profile of plastics containing landfill samples. Therefore organic carbon contents are relatively high compared to other stable landfills as shown by a prediction model for TOC contents based on heat flow profiles and partial least squares regression (PLS-R). The stability of the landfill samples, expressed by the relation of CO2 release and enthalpies, was compared to unreactive landfills, archeological samples, earthlike materials and hardly degradable organic matter. Due to the material composition and the aging process the landfill samples are located between hardly degradable, but easily combustible materials and thermally resistant materials with acquired stability.  相似文献   
66.
What resources should be committed to the control of invasive species? This study is based on a survey of nature conservation and forestry authorities, wildlife trusts and private landowners which investigated the extent of the ecological and economic impacts of the invasive non-native plant Rhododendron ponticum in the British Isles. There are data on 52,000 ha of land affected by R. ponticum, more than 30,000 ha of it in nature reserves. For nearly all nature reserves, displacement of native species and habitat changes were both reported. In 2001, respondents controlled 1275 ha of R. ponticum at a cost of pound 670,924. To test the optimality of this, we apply a model of social expenditure. The external costs of R. ponticum control are estimated from the probability that it will spread to contiguous sites and the damage done on invaded sites. These are then used to calculate the socially optimal level of expenditure on R. ponticum control, and the funding gap it identified by comparing the result with current levels of expenditure. The results suggest that a socially optimal level of control effort requires a significant increase in social funding for R. ponticum control, although the size of the increase varies between landholders.  相似文献   
67.
After 30 years of economic reform since opening to the outside world in 1978, China's Gross Domestic Product (GDP) has increased by 150% over the past 15 years. The sustainability of such intense economic activity has been questioned from the perspectives of the social, environmental, and economic dimensions of sustainability. In this study, we assessed the spatial and temporal trends in sustainable development in two sensitive agricultural areas of China: Dezhou district, a well-developed region, and Guyuan district, an underdeveloped region. We used the pressure–state–response (PSR) model and a participatory approach that involved local experts to select and evaluate 27 area-specific indicators, then calculated changes in their values from 1985 to 2002. We aggregated these indicators into dimension- and PSR-specific indices to assess the sustainability of development in both regions. There two regions differed greatly in sustainability, but the current status of sustainable development raises concerns in both areas, especially from the perspective of balancing the three dimensions of sustainability. In 2002, Dezhou district performed well economically, with an index value of 0.78 (where 1.0 = sustainable), followed by environmental and social sustainability (both with index values of 0.48). All three indices have increased since 1985 (by 0.17, 0.25, and 0.13, respectively). In Guyuan district, environmental sustainability was highest (with an index value of 0.73), followed by economic and social sustainability (values of 0.55 and 0.37, respectively), but economic sustainability has decreased by 0.04 since 1985, whereas environmental and social sustainability increased by 0.18 and 0.12, respectively. To promote sustainable regional development, development priorities should be determined by considering both the regional and temporal variation in the three sustainability indices.  相似文献   
68.
Abandoned landfills and dumps, where untreated waste materials were deposited in the past, are a main anthropogenic source of relevant gaseous emissions. The determination of stability is a crucial target in the context of landfill risk assessment. FTIR spectroscopy and simultaneous thermal analysis in association with multivariate statistical methods were applied to landfill materials in order to get information on the kind of waste and its reactivity. The spectral and thermal patterns are fingerprints of the material. Industrial waste and the material from a 5-year-old reactor landfill were distinguished from the defined classes of mechanically-biologically treated ("MBT") waste and 30 to 40-year-old stable landfills containing municipal solid waste and construction waste ("LF") by a classification model based on soft independent modeling of class analogy (SIMCA). Degradation experiments were carried out with the fresh material originating from one MBT plant that was subjected to aerobic and anaerobic conditions in lab-scale reactors. These samples were compared to samples of one reactor landfill and to the landfill fraction from the MBT plant to demonstrate the efficiency of the biological pretreatment before final disposal. Prediction models that are based on spectral or thermal characteristics and the corresponding reference analyses were calculated by means of a partial least squares regression (PLS-R). The developed models of the biological oxygen demand (BOD) and the dissolved organic carbon (DOC) were based on spectral data, the models of the total organic carbon (TOC) and total nitrogen (TN) were based on thermal data (heat flow profiles and mass spectra of combustion gases). Preliminary results are discussed. The enthalpy of the materials decreases with progressing mineralization, whereas the enthalpy of the remaining organic matter increases. The ratio of the enthalpies was used as an indicator of stability. Selected samples comprising old landfills, a recent reactor landfill, MBT landfills and MBT materials were classified according to the calculated ratios.  相似文献   
69.
Journal of Polymers and the Environment - Poly(lactic acid) (PLA) and PLA/5% Babassu compounds were molten mixed, afterwards aged at temperatures ranging from 50 to 90 °C during 15 to...  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