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161.
分形块体理论及其在三峡高边坡稳定分析中的应用 总被引:4,自引:0,他引:4
把分形几何与块体理论相结合,提出了分形块体理论,建立了分形块体理论赤平解析法,并将其应用于三峡永久船闸高边坡稳定性分析中。结果表明:分形块体理论符合工程实际,是分析裂隙岩体工程稳定性行之有效的可靠方法。 相似文献
162.
Brian G. Field 《Journal of Environmental Planning and Management》1984,27(2):68-78
This paper focuses on the development plan activities of the London Boroughs and simply seeks to explain the relatively limited progress that has been made in the preparation and adoption of statutory local plans, by showing how production was constrained as local planners were caught up in the shifting ground of contemporary planning theory. The author suggests that uncertainty about the acceptable scope and content of local plans, at a time when planners were being encouraged to extend the emphasis of their work beyond the purely physical, led to serious problems as planners began to experiment with new approaches to local planning but failed to appreciate the operational implications of each approach. 相似文献
163.
This paper presents an integrated system for the assessmentof technical and non-technical measures that are putforward in order to reduce air pollution levels in urbanareas. In contrast to the majority of the currentlyemployed assessment tools, this system allows for theevaluation of any proposed air pollution control measure interms of its combined impact on air quality and socialwelfare, by correlating the environmental and economicaspects of alternative air pollution abatement solutions.Based on the multi-pollutant, multi-effect concept, thesystem presented aims in providing policy-makers with areliable tool for the objective assessment of the mostcost-effective packages of measures, the latter beingallocated according to the particular features and needs ofthe areas examined. 相似文献
164.
矿产资源经济区划的理论与方法 总被引:2,自引:0,他引:2
矿产资源经济区划是保护与合理开发利用矿产资源、实现资源优化配置和区域经济可持续发展的基础。本文依据经典的区位理论和地域分工理论,应用系统分析的方法,建立了矿产资源经济区划的一般程序,并归纳了定量分析中必要的技术手段和方法路线。 相似文献
165.
Acid rain in Asia 总被引:3,自引:0,他引:3
Acid rain has been an issue of great concern in North America and Europe during the past several decades. However, due to the passage of a number of recent regulations, most notably the Clean Air Act in the United States in 1990, there is an emerging perception that the problem in these Western nations is nearing solution. The situation in the developing world, particularly in Asia, is much bleaker. Given the policies of many Asian nations to achieve levels of development comparable with the industrialized world—which necessitate a significant expansion of energy consumption (most derived from indigenous coal reserves)—the potential for the formation of, and damage from, acid deposition in these developing countries is very high. This article delineates and assesses the emissions patterns, meteorology, physical geology, and biological and cultural resources present in various Asian nations. Based on this analysis and the risk factors to acidification, it is concluded that a number of areas in Asia are currently vulnerable to acid rain. These regions include Japan, North and South Korea, southern China, and the mountainous portions of Southeast Asia and southwestern India. Furthermore, with accelerated development (and its attendant increase in energy use and production of emissions of acid deposition precursors) in many nations of Asia, it is likely that other regions will also be affected by acidification in the near future. Based on the results of this overview, it is clear that acid deposition has significant potential to impact the Asian region. However, empirical evidence is urgently needed to confirm this and to provide early warning of increases in the magnitude and spread of acid deposition and its effects throughout this part of the world. 相似文献
166.
ABSTRACT: The detrimental impacts of acid rain have become widely publicized, but effective and equitable methods to mitigate the acid rain problem remain to be found. This paper focuses on conflicts involved in allocation of the total emission loads to be reduced to respective pollution sources of acid rain, and proposes a game-theory approach to the resolution of the conflict. With an example abstracted from a hypothetical case study in the United States of America and Canada, a systematic analysis is performed and policy implications of the results examined to assess the applicability of the proposed model. 相似文献
167.
The extensive use of synthetic organic pesticides in this country during the past twenty-five years has resulted in widespread pollution of our water resources. An obvious detrimental effect of such pollution has been observed in the numerous fish kills that have occurred. The most widely used pesticides, and the ones that have been implicated in the vast majority of the pollutional episodes, are the chlorinated hydrocarbon insecticides. These compounds, generally speaking, have almost no solubility in water, are subject to very slow microbial degradation if any at all, and are so resistent to natural degradation forces they can persist almost indefinitely in aqueous environments; characteristics that are all detrimental from a stream pollution standpoint. In addition, studies have shown that, as a group, the chlorinated hydrocarbons are more toxic to higher forms of aquatic life than other chemicals widely used for pest control. Because of these undesirable characteristics, present trends are to discontinue using these highly toxic, persistent compounds for pest control in outdoor areas. Legislation banning the sale of DDT has been introduced. Similar legislation controlling the use of several of the chlorinated hydrocarbon pesticides is probably the most effective way to reduce pollution. 相似文献
168.
灰关联分析在故障树诊断中的应用 总被引:8,自引:0,他引:8
介绍一种灰色诊断法。在故障诊断模式识别中,运用灰关联分析,依据故障树的底事件重要度,通过关联度计算及排序,对故障树分析中,各种故障模式发生的可能性大小作出了准确的判断,从而为处理事故的先后、缓急提供了依据。 相似文献
169.
论我国重大危险源辨识标准 总被引:17,自引:2,他引:15
简要介绍了国外重大危险设施的辨识标准研究情况,并结合我国重大危险源普查试点工作的初步辨识标准,以及几个试点城市普查的数据分析,提出了我国重大危险源辨识最小标准的建议 相似文献
170.
Barry J. Barnett 《Disasters》1999,23(2):139-155
Governments often provide grants or low-interest loans to disaster victims. Yet these programmes have proven to be quite costly. In addition, questions have been raised about associated behavioural incentives. Conceptually, government disaster insurance programmes should be more efficient, consistent and equitable than ex post facto disaster relief in the form of grants and loans. Yet the performance of government disaster insurance programmes has been mixed, at best. This article reviews the history of US federal natural disaster assistance to individuals and concludes with a recommendation for a new government role in the provision of disaster insurance. 相似文献