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   19篇
  免费   0篇
废物处理   1篇
环保管理   3篇
综合类   2篇
基础理论   2篇
污染及防治   8篇
评价与监测   1篇
社会与环境   1篇
灾害及防治   1篇
  2021年   1篇
  2013年   1篇
  2009年   3篇
  2008年   1篇
  2007年   1篇
  2005年   1篇
  2004年   2篇
  2002年   1篇
  1998年   1篇
  1984年   4篇
  1982年   1篇
  1981年   1篇
  1970年   1篇
排序方式: 共有19条查询结果,搜索用时 312 毫秒
1.
This paper explores the attitudes of landowners across Ireland to the wider provision of public access for recreational walking using a multinomial logit model. The study also investigates the level of compensation required to improve the supply of this public good. Results indicate that 51% of landowners are not willing to provide access (non-providers), 21% are willing to provide access free of charge (free providers) and 28% seek compensation (willing providers). The findings indicate that participation by landowners in a proposed public access scheme is influenced by landowners' experience with walkers, farm type, farm insurance costs, household demographics, regional variations, opportunity cost of land and participation in other agri-environment schemes. Mean willingness-to-accept for landowners willing to facilitate improved public access for walking was found to be €0.27 per metre of walkway.  相似文献   
2.
Ulva lactuca (commonly known as sea letuce) is a green sea weed which dominates Green Tides or algae blooms. Green Tides are caused by excess nitrogen from agriculture and sewage outfalls resulting in eutrophication in shallow estuaries. Samples of U. lactuca were taken from the Argideen estuary in West Cork on two consecutive years. In year 1 a combination of three different processes/pretreatments were carried out on the Ulva. These include washing, wilting and drying. Biomethane potential (BMP) assays were carried out on the samples. Fresh Ulva has a biomethane yield of 183 L CH4/kg VS. For dried, washed and macerated Ulva a BMP of 250 L CH4/kg VS was achieved. The resource from the estuary in West Cork was shown to be sufficient to provide fuel to 264 cars on a year round basis. Mono-digestion of Ulva may be problematic; the C:N ratio is low and the sulphur content is high. In year 2 co-digestion trials with dairy slurry were carried out. These indicate a potential increase in biomethane output by 17% as compared to mono-digestion of Ulva and slurry.  相似文献   
3.
N Adams  AJ Dobbs 《Chemosphere》1984,13(8):965-971
Two different test methods for assessing the toxicity of aminotriazole to Selenastrum capricornutum are compared. Growth medium composition is demonstrated to have a significant effect on the toxicity of aminotriazole.  相似文献   
4.
5.
The high seas provide a variety of ecosystem services that benefit society. There have, however, been few attempts to quantify the human welfare impacts of changes to the delivery of these benefits. We assessed the values of several key ecosystem service benefits derived from protecting ecosystems in the high seas of the Flemish Cap through choice experiments conducted in Canada, Norway, and Scotland. Rather than solely eliciting public willingness to pay, we also explored the determinants of variance in the estimates of willingness to pay. We aimed to determine how much respondents were willing to pay for high-seas ecosystems conservation, which factors influence individuals’ willingness to pay, and whether individuals in Canada had a higher willingness to pay relative to those living in Norway and Scotland. This latter point captures distance-decay effects. On average, the public placed positive value on conserving high-seas ecosystems and on developing economic activities related to the exploitation and exploration of marine resources, despite a lack of awareness and familiarity with these environments. Distance-decay effects on willingness to pay were not clear. Scots had the highest willingness to pay and the Norwegians the lowest willingness to pay for all attributes, with the only exception being willingness to pay for a large increase in new jobs, in which case Canadians’ willingness to pay was higher than Scots’. The public's willingness to pay was influenced by sociodemographic characteristics and their perceptions of high-seas ecosystems. Our results provide evidence of the impacts of high-seas governance on human welfare and that improved governance could increase the value people place on high-seas ecosystems and the services they produce.  相似文献   
6.
We have examined the sensitivity of sequential two photon laser induced fluorescence (LIF) detection of elemental mercury, Hg(0) in the gas phase. The most sensitive approach involves an initial laser excitation of the 6(3)P1-6(1)S0 transition at 253.7 nm, followed by excitation with a second laser to the 7(1)S0 level. Blue shifted fluorescence is observed on the 6(1)P1-6(1)S0 transition at 184.9 nm. The excitation scheme, involving sequential excitation of two atomic transitions, followed by detection of the emission from a third is extremely specific and precludes detection of anything other than atomic mercury. Using our 10 Hz laser system we have achieved a detection sensitivity of 0.1 ng m(-3) at a sampling rate of 0.1 Hz, i.e. averaging 100 laser shots at a pressure of one atmosphere in air. At low concentrations we sampled simultaneously with an automated mercury analyzer (Tekran 2537A), to ensure accuracy. We have examined the linearity of the technique, generating flows containing mercury concentrations between 1 and 10,000 ng m(-3) using a permeation tube and dynamic dilution, but relying on the concentrations given by the Tekran at low levels and the concentration calculated from dilution at high levels. We find that the detection is linear over the five orders of magnitude that we were able to vary the concentration. Our measured detection limits in He and Ar are much lower as these gases are inefficient fluorescence quenchers.  相似文献   
7.
The German cockroach is the most common pest of urban, low-income housing in the United States and is associated with high pesticide use by residents. Cockroach allergen is implicated in asthma exacerbation and initiation and in the growing social and medical aspects of the disease. A safe and secure home environment is an environmental justice issue, and environmentally sound and effective models of cockroach control are needed in public and low-income multifamily housing. One model that offers potential is the integrated pest management (IPM) peer educator model (IPM Educator) in public housing as a component of IPM. A pre-post-analysis of an IPM Educator pilot programme in Boston public housing was undertaken. Thirty-four moderate- to high-infested units received baseline assessment and three applications of gel baits and IPM treatment by a pest control operator. Before the first pest control application, residents received written notice to prepare their units for treatment, a standard procedure. Before the second and third pest control treatments, an IPM Educator instructed residents in basic pest biology and habits, preparation for treatment, and the role of sanitation in pest control. Results showed a significant improvement in rate of preparation for pest control treatment after the IPM Educator intervention when compared with the preparation rate before the education intervention, and a significant reduction in cockroach populations by the third visit in units that were prepared and had improved sanitation, when compared with unprepared units and unclean units. The IPM peer educator is a promising, low-cost model of educating and engaging residents of urban, low-income, multifamily housing in environmentally sound pest control, thereby giving them some power and control over their living environment. It is also a potential source of professional training and jobs for public housing and other low-income housing residents.  相似文献   
8.
AJ Dobbs  C Grant 《Chemosphere》1981,10(10):1185-1193
The octachlorodibenzo-p-dioxin (OCDD) concentrations have been determined in aged samples of commercial pentachlorophenol (PCP), in wood protection formulations containing PCP and in wood treated with PCP as a preservative or as an anti-sapstain treatment. The concentrations of OCDD found in the various samples are within the range expected from the amount of commercial PCP initially present in the samples. In view of the known stability of OCDD the results are interpreted as indicating that the formulation, treatment and ageing processes have not led to any substantial conversion of PCP to OCDD; although one result indicates that outdoor exposure of treated samples increased the OCDD concentration by a factor of approximately 2 after 312 years. Analysis of aged samples of treated wood indicate that OCDD is lost much less rapidly from the wood than PCP.  相似文献   
9.
Technetium, uranium and neptunium may all occur in the environment in more than one oxidation state (IV or VII, IV or VI and IV or V respectively). The surface of mackinawite, the first-formed iron sulfide phase in anoxic conditions, can promote redox changes so a series of laboratory experiments were carried out to explore the interactions of Tc, U and Np with this mineral. The products of reaction were characterised using X-ray absorption spectroscopy. Technetium, added as TcO4(-), is reduced to oxidation state IV and forms a TcS(2)-like species. On oxidation of the mackinawite in air to form goethite, Tc remains in oxidation state IV but in an oxide, rather than a sulfide environment. At low concentrations, uranium forms uranyl surface complexes on oxidised regions of the mackinawite surface but at higher concentrations, the uranium promotes surface oxidation and forms a mixed oxidation state oxide phase. Neptunium is reduced to oxidation IV and forms a surface complex with surface sulfide ions. The remainder of the Np coordination sphere is filled with water molecules or hydroxide ions.  相似文献   
10.
The measurement of travel costs in recreational demand modeling has been a contentious issue for many decades. This article explores the use of a number of alternative methods of incorporating time costs in the travel cost modeling process. Travel cost values where the opportunity cost of time is excluded, where it is included as a percentage of the individual's reported wage rate and where it based on an estimated wage from a secondary data source (the European Community Household Panel) are compared and then used in a conditional logit model to estimate the demand for whitewater kayaking in Ireland. We then evaluate the effect of different treatments of the cost of travel time on the welfare impacts of a number of different management scenarios for kayaking rivers in Ireland, and find that statistically significant differences emerge.  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