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31.
海洋生态系统健康评价的底栖生物指数法研究进展 总被引:2,自引:0,他引:2
海洋大型底栖无脊椎动物能对自然和人为活动导致的水和沉积物质量变化做出可预测的响应,因此利用底栖生物作为海洋生态环境监测的生物指标和进行系统健康度量的生物指数已经得到了广泛的认可.本文比较分析了几种常用的和正在发展的海洋生态系统健康和生态环境质量状况评估的底栖生物指数,包括指示生物法、Shannon-Wiener多样性指数、BI指数、AMBI指数和Bentix指数,总结了这几种生物指数的应用和特性,探讨了底栖生物指数在实际应用中可能存在的问题和解决的办法,以期为我国海洋生态系统健康评估工作提供参考. 相似文献
32.
杨昊 《成都信息工程学院学报》2009,24(5):529-531
结合目前国内职业安全、职业健康方面的现状,分析存在的问题及原因,提出在当前形势下,需要政府、企业、员工以及全社会的共同努力,推进职业健康安全管理体系的建设。 相似文献
33.
34.
To improve geographical accessibility to health facilities in rural Ghana, it has been recommended that additional health facilities be built. Resource constraints make this recommendation infeasible. Using location-allocation models, this paper demonstrates that in the Suhum District of Ghana substantial improvements in accessibility can be achieved with better locational choices and without additional facilities. Also, additional facilities will produce little improvement in accessibility if location is not explicitly considered. The paper demonstrates the utility of location-allocation models for improving accessibility to services in the Third World. 相似文献
35.
Raul Borges Guimarães 《New Zealand geographer》2007,63(2):97-105
Abstract: This paper offers a geographical perspective on the way in which health regions have been defined and established in São Paulo as part of overall Brazilian health policy. To accomplish this, I first situate the Brazilian case in the international debate over the regionalization of health services. Second, I examine health regionalization in the case of São Paulo and show how the process is dynamic and complex, involving geographical scales that go well beyond the administrative boundaries of Brazilian municipalities. 相似文献
36.
The evolving role of voluntarism in ageing rural communities 总被引:1,自引:0,他引:1
37.
环境与健康的评估问题和空间分析 总被引:1,自引:0,他引:1
评估环境污染对人民健康影响的研究需要结合空间,时间和统计分析,并吸引不同学科背景的研究人员合作研究,可是,在这个研究领域内,最重要的问题是研究结论的不可靠性程度很高,不同的研究方法会导致不同的结论,一个有系统的研究架构拥有不同的空间分析方法将会减少结论的可疑程度,有效的环保政策是需要可靠的研究成果,文中首先介绍在环境与健康的评估研究领域的四大重要问题,指出这项研究需要这项研究需要空间分析和地理信息系统方法,从而提出一个空间分析的研究框架和内裹的方法,通过路易斯安纳州的一个污染地点和肿瘤发病率关系研究实例,指出这项研究领域的各种问题和空间分析架构的重要性。 相似文献
38.
大连湾60多年来生态环境地质演化 总被引:5,自引:1,他引:5
依据对大连湾60多年来沉积柱的生态环境地质演化研究,发现其污染变化可以分为3个时期:①1933-1974年为洁净时段;②1974-1989年为污染较重时段;③1989-1997年为严重污染时段。若视第一时段的污染度为0,则第二时段的污染度为第一时段的8倍,第三时段的污染度为第一时段的25倍,可见污染度增加是非常迅速和严重的。其中Cd、Pb、As、S、Zn5种元素含量增加最快。1997年大连湾表面沉积物中Cd、Hg、Pb、As的含量分别为自然背景值的81.42倍、6.0倍、7.54倍、3.82倍,表明大连湾污染的严重性。研究发现自1950年以来大连湾生物多样性急剧下降,说明污染度增加已对生命健康造成严惩的影响。大连湾的臭水套已成为一个生物多样性异常低下的、超级污染的环境,是一颗巨大的隐性化学定时炸弹。 相似文献
39.
Evolution of accelerographs, data processing, strong motion arrays and amplitude and spatial resolution in recording strong earthquake motion 总被引:1,自引:0,他引:1
This paper presents a review of the advances in strong motion recording since the early 1930s, based mostly on the experiences in the United States. A particular emphasis is placed on the amplitude and spatial resolution of recording, which both must be ‘adequate’ to capture the nature of strong earthquake ground motion and response of structures. The first strong motion accelerographs had optical recording system, dynamic range of about 50 dB and useful life longer than 30 years. Digital strong motion accelerographs started to become available in the late 1970s. Their dynamic range has been increasing progressively, and at present is about 135 dB. Most models have had useful life shorter than 5–10 years. One benefit from a high dynamic range is early trigger and anticipated ability to compute permanent displacements. Another benefit is higher sensitivity and hence a possibility to record smaller amplitude motions (aftershocks, smaller local earthquakes and distant large earthquakes), which would augment significantly the strong motion databases. The present trend of upgrading existing and adding new stations with high dynamic range accelerographs has lead to deployment of relatively small number of new stations (the new high dynamic range digital instruments are 2–3 times more expensive than the old analog instruments or new digital instruments with dynamic range of 60 dB or less). Consequently, the spatial resolution of recording, both of ground motion and structural response, has increased only slowly during the past 20 years, by at most a factor of two. A major (and necessary) future increase in the spatial resolution of recording will require orders of magnitude larger funding, for purchase of new instruments, their maintenance, and for data retrieval, processing, management and dissemination. This will become possible only with an order of magnitude cheaper and ‘maintenance-free’ strong motion accelerographs. In view of the rapid growth of computer technology this does not seem to be (and should not be) out of our reach. 相似文献
40.
While it is intuitively attractive to link health status and the quality of housing, it is methodologically complex to identify the relative importance of housing because individual characteristics and environmental variables act as confounders. A secondary issue is that the data sets which contain detailed data on health status and environmental variables often contain only limited data on housing. Similarly, housing surveys rarely contain detailed data on health and environmental variables. Respondents from Montreal, Toronto and Vancouver in the public use micro-data files of the 1996/97 cycle of the National Population Health Survey make up the data sets for a series of logistic regression models where health status, allergies, asthma, arthritis, migraines and bronchitis/emphysema act as the dependent variables. Sets of variables which measure housing, the environment (smoking and alcohol consumption) and the socio-economic status of individuals are used as independent variables. The issues of confounders and the limitations of the data are illustrated by the results of the analysis. If we are to go beyond local area surveys and carry out broader analyses of the links between health status and the quality of housing, researchers and data collection agencies will need to re-think the artificial divisions between these two critical aspects of peoples' lives. 相似文献