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   13篇
  免费   0篇
废物处理   1篇
环保管理   1篇
综合类   3篇
基础理论   4篇
污染及防治   1篇
评价与监测   2篇
社会与环境   1篇
  2023年   1篇
  2021年   1篇
  2016年   1篇
  2013年   2篇
  2012年   1篇
  2008年   2篇
  2007年   1篇
  2005年   1篇
  2002年   2篇
  1983年   1篇
排序方式: 共有13条查询结果,搜索用时 99 毫秒
1.
The aim of this study was to analyse the relationship between the distribution of hay-fever patients in the city of Córdoba, south-western Iberian Peninsula, and the specific atmospheric biological content originating from local sources. Four different districts were established in the metropolitan area of the city, according to vegetational and urbanistic characteristics. Air samples were taken in each area using portable Hirst-type samplers (Lanzoni VPPS 1000) and the spectrum of biological content was defined. Patients attending the Allergy Unit at Córdoba Teaching Hospital in 2000 with allergic rhinitis and/or asthma, and displaying a positive reaction to aeroallergen extracts, were distributed within the areas as a function of their district of residence. Aerobiological results revealed differences in pollen content between areas, in terms of both quantity and number of pollen types recorded. These differences were largely due to proximity to rural areas, prevalence of pollen from typically urban species and the possible effect of urban architecture as a barrier to the dispersal/ concentration of particles and other pollutants. Patients were not uniformly distributed within the city. The majority lived in districts in which pollen from rural species was mixed with pollen from ornamentals. Patients living in typically urban districts displayed a higher prevalence of allergy to pollen from ornamentals. It is concluded that a high degree of exposure to the same environment may influence the development of sensitisation to the particular pollen load associated with that area.  相似文献   
2.
Faced with society's increasing expectations, the Common Agricultural Policy (CAP) review considers environmental management to be an ever more critical criterion in the allocation of farm subsidies. With the goal of evaluating the environmental friendliness of farm practices, France's agricultural research and extension services have built a range of agricultural/environmental diagnostic tools over recent years. The objective of the present paper is to compare the five tools most frequently used in France: IDEA, DIAGE, DIALECTE, DIALOGUE and INDIGO. All the tools have the same purpose: evaluation of the impact of farm practices on the environment via indicators and monitoring of farm management practices. When tested on a sample of large-scale farms in Picardie, the five tools sometimes produced completely different results: for a given farm, the most supposedly significant environmental impacts depend on the tool used. These results lead to differing environmental management plans and raise the question of the methods' pertinence. An analysis grid of diagnostic tools aimed at specifying their field of validity, limits and relevance was drawn up. The resulting comparative analysis enables to define each tool's domain of validity and allows to suggest lines of thought for developing more relevant tools for (i) evaluating a farm's environmental performance and (ii) helping farmers to develop a plan for improving practices within the framework of an environmental management system.  相似文献   
3.
Although mistimed reproduction (i.e., time-lag between peak food supply and offspring food demand) has been attributed to habitat modifications or climate change in recent avian investigations, earlier breeding parents have higher reproductive success in many habitats. Here we compare first and second broods in great tits (Parus major L.) from two Mediterranean oak habitats differing significantly in the timing (about 5 weeks), but not the amount of caterpillar supply required to rear chicks. The study indicates that both the extent of mistimed reproduction and the breeding date per se influence breeding performance in this study system. The text was submitted by the authors in English.  相似文献   
4.
The zinc content of intestinal epithelial cells in human jejunum and ileum has been measured using X-ray microanalysis. The range of values was wide, the highest being found in stem cells and enterocytes. Significant differences were found in jejunum from gastric carcinoma patients and ileum from Crohn's disease patients compared with patients with non malignant, non inflammatory disease.  相似文献   
5.
Zinc is an essential trace element to maintain human and generally mammal homeostasis; its biological signification could be explained through the participation or as structural element of more than 200 protein molecules in mammals.

The synthesis of proteins in spleen and thymus of rats is induced by zinc, a fact which moved us to purify and isolate such proteins, before proceeding to its identification or characterization. Rats are treated with zinc during 4 weeks and then sacrificed; blood is extracted under light ether anesthesia. The extracts of thymus and spleen were prepared by homogenization with Tris‐HC1 buffer 1.0 × 10‐2M pH 7.4 and submitted to Sephadex G‐75 column (40 × 1.6 cm) after centrifugation and filtration through 0.45 μ filters. The elution profile of proteins were established at 253 and 280 nm, and zinc concentration was measured by atomic absorption spectrophotometry. The peak containing zinc was submitted to a second column of Sephadex G‐25 (40×1.6 cm) obtaining a peak of purified protein with physico‐chemical characteristics similar to metallothionein.  相似文献   
6.
7.
We study the horizontal surface mixing and the transport induced by waves in a coastal environment. A comparative study is addressed by computing the Lagrangian coherent structures, via Finite Size Lyapunov Exponents, that arise in two different numerical settings: with and without wave coupled to currents. In general, we observe that mixing is increased in the area due to waves. Besides, the methodology presented here is tested by deploying a set of eight Lagrangian drifters at different locations. This dynamical approach is shown as a valuable tool to extract information about transport, mixing and residence embedded in the Eulerian time dependent velocity fields obtained from numerical models.  相似文献   
8.
9.
The techniques of diffusive equilibrium in thin films (DET) and diffusive gradients in thin films (DGT) were used in the outer section of Songkhla Lake, Thailand in order to obtain high-resolution profiles of total dissolved and labile trace metals in the sediment pore water and investigate benthic fluxes. Six DET probes and six DGT probes were deployed at the mouths of the Phawong, Samrong and U-Taphao canals. A close correspondence could be observed between the high-resolution profiles of Fe and As, revealing a close link between the reductive remobilization of Fe oxides and the reduction of As(V). Co and Ni DGT profiles showed a close correspondence with Mn, but a narrow mobilization zone. Reductive mobilization of Mn oxides and associated metals and sulfide precipitation control the behaviour of these metals. The DGT profiles of Cu, Zn, Cd and Pb show surface maximum, probably linked to organic matter degradation. Important benthic fluxes, especially for As, were found at the mouths of the U-Taphao and Phawong canals.  相似文献   
10.
This article provides a perspective on nature-based solutions. First, the argument is developed that nature-based solutions integrate social and ecological systems. Then, theoretical considerations relating to relational values, multifunctionality, transdisciplinarity, and polycentric governance are briefly outlined. Finally, a conceptual model of the social–ecological system of nature-based solutions is synthesised and presented. This conceptual model comprehensively defines the social and ecological external and internal systems that make up nature-based solutions, and identifies theoretical considerations that need to be addressed at different stages of their planning and implementation The model bridges the normative gaps of existing nature-based solution frameworks and could be used for consistent, comprehensive, and transferable comparisons internationally. The theoretical considerations addressed in this article inform practitioners, policymakers, and researchers about the essential components of nature-based solutions. The conceptual model can facilitate the identification of social and ecological interconnections within nature-based solutions and the range of stakeholders and disciplines involved.  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