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851.
852.
853.
John B. Braden Noelwah R. Netusil Richard F Kosobud 《Journal of the American Water Resources Association》1994,30(5):781-791
ABSTRACT: This paper summarizes key provisions of the Clinton Administration's proposals for change in the Clean Water Act. Two of the important themes for change are tougher controls for non-point source pollution and the use of market-based instruments. A detailed analysis of market-based abatement suggests limited potential for reducing costs. The keys to nonpoint source pollution control are clearer definition of property rights combined with changes in government programs that encourage polluting activities. 相似文献
854.
我国钢铁工业废水治理及其发展趋势 总被引:1,自引:0,他引:1
我国水资源人均拥有量仅为世界人均拥有量的四分之一,而且降水在时空分布上很不均衡。这一现实,决定了节省水资源,保护水环境是我国一项长期的战略任务。文章概要地叙述了钢铁工业废水治理及其发展过程。作者认为,要从根本上解决钢铁工业废水对水环境的污染与破坏,必须采取综合防治措施,并把整套循环用水技术引入生产工艺过程,使废水与污染物都作为资源加以回收,并实现循环利用。上述过程的实质,是模拟大自然生物圈循环运行 相似文献
855.
Elizabeth W. Sulzman Karen A. Poiani Timothy G. F. Kittel 《Environmental management》1995,19(2):197-224
The rapid increase in atmospheric concentrations of greenhouse gases has caused concern because of their potential to alter
the earth's radiation budget and disrupt current climate patterns While there are many uncertainties associated with use of
general circulation models (GCMs), GCMs are currently the best available technology to project changes in climate associated
with elevated gas concentrations. Results indicate increases in global temperature and changes in global precipitation patterns
are likely as a result of doubled CO2.
GCMs are not reliable for use at the regional scale because local scale processes and geography are not taken into account.
Comparison of results from five GCMs in three regions of the United States indicate high variability across regions and among
models depending on season and climate variable. Statistical methods of scaling model output and nesting finer resolution
models in global models are two techniques that may improve projections.
Despite the many limitations in GCMs, they are useful tools to explore climate-earth system dynamics when used in conjunction
with water resource and ecosystem models. A variety of water resource models showed significant alteration of regional hydrology
when run with both GCM-generated and hypothetical climate scenarios, regardless of region or model complexity. Similarly,
ecological models demonstrate the sensitivity of ecosystem production, nutrient dynamics, and distribution to changes in climate
and CO2 levels.
We recommend the use of GCM-based scenarios in conjunction with water resource and ecosystem models to guide environmental
management and policy in a “no-regrets” framework or as part of a precautionary approach to natural resource protection. 相似文献
856.
介绍了喷射钻井井底流场特性、喷嘴射流破岩机理、脉冲射流喷嘴、新型水力流道钻头的研究与应用情况,以及水射流技术在石油钻井用钻头上的应用前景。 相似文献
857.
磨料水射流除鳞技术在钢厂的应用 总被引:2,自引:0,他引:2
为了暴露各种钢材在热轧过程中产生的表面缺陷,需清除附于其上的氧化铁皮,称之为“除鳞”。传统的除鳞方法有酸洗、表面剥皮、喷丸处理等,这些方法存在很多缺点。本文介绍已在湖南涟钢用于生产的磨料水射流除鳞生产线,用磨料水射流除鳞具有速度快、质量高、成本低、操作简便等独特的优点。 相似文献
858.
根据生产需要,我们研制了“水射流自动清洗机”,采用水射流技术与清洗剂相结合,完成工序间、装配前的机械零件(尤其带有小孔、盲孔等多孔零件)的清洗,取得了普通清洗方法难以达到的清洗效果。该机在国内同类型清洗机中,首先采用水射流技术,全部流程,由PC机控制,加上水循环处理系统,其清洗自动化程度高,清洗速度快,清洗液消耗少,在实际生产中取得了良好效果。 相似文献
859.
Joanne McEntire 《Environmental management》1989,13(3):287-295
Water is a relatively scarce resource in Arizona, especially since the recent urban growth booms of Phoenix and Tucson. Arizona's 1980 Groundwater Management Act was the precursor to current water-transfer conflicts between urban buyers, rural farmers, and third parties. Water farms are bought with the intention to transfer their appurtenant groundwater to the two major metropolitan areas. As water markets have emerged, differing values and public interest issues have become apparent, while the state legislature attempts to resolve inequities. Site-specific transfer disputes, as well as policy-making conflicts, offer suitable situations for a mediation process. Equity- and efficiency-based criteria are suggested as the basis for resolving water-transfer conflicts, and a mediation process is proposed. However, third parties must develop an agenda, and a balance of power should be attained before mediation can effectively forge an agreement on water-transfer policies. The attainment of statewide policies generated through a mediated process has the potential to expand long-range regional water planning and management. 相似文献
860.
Nicomedes D. Briones 《Environmental management》1987,11(3):335-344
Environmental problems caused by improper mine tailings disposal in the Baguio district include pollution of the Lower Agno River system and its watershed and siltation of irrigation canals in the Pangasinan plains. Direct economic losses are from reduced agricultural production due to siltation of irrigation works and farmlands. To check the adverse ecological effects of improper mine tailings disposal, government regulations have been imposed on mining firms. Several disposal schemes have been proposed, including the use of the reservoir of a multipurpose project to be sited in the watershed where the mines are located. Because of siltation problems, however, trapping the tailings in the reservoir will diminish the economic benefits that can be derived from the project. 相似文献