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201.
Employing in-depth, elite interviews, this empirical research contributes to understanding the dynamics among policy windows, policy change, and organizational learning. First, although much of the research on agenda setting—how issues attract enough attention that action is taken to address them—has been conducted at the national scale, this work explores the subnational, regional scale. With decentralization, regional-scale environmental decision-making has become increasingly important. Second, this research highlights the role of policy windows and instances of related organizational learning identified by natural resources managers. Having practitioners identify focusing events contrasts with the more typical approach of the researcher identifying a particular focusing event or events to investigate. A focusing event is a sudden, exceptional experience that, because of how it leads to harm or exposes the prospect for great devastation, is perceived as the impetus for policy change.  相似文献   
202.
ABSTRACT: A national and interregional programming model was used in projecting the impacts of alternative energy policies and prices on agricultural production, land use, and irrigation. The alternatives analyzed include (a) natural gas deregulation, (b) natural gas curtailment, (c) doubled energy prices, and (d) tripled energy prices. These alternatives are compared with a base alternative where prices and conditions are at normal levels. Restraints in the model control availability of water, land, nitrogen fertilizers, and energy. Water production functions were used to adjust water use to conform with projected energy prices and policies. Natural gas curtailment would have the largest effect on nitrogen use on irrigated land. Values or shadow prices for lands that remains in irrigation would increase under all of the alternatives because of reduced supply. Increased energy prices generally would increase use of surface water for irrigation and reduce use of ground water due to higher pumping costs. Reductions of 50 percent or more in ground water use would occur in the South Central and Western regions of the United States. Water supply prices increase under all of the alternatives; with the amount varying by regions and the policy or price situation.  相似文献   
203.
纳米碳管是一种新型的纳米材料,其独特的分子结构和性能引起了人们的广泛关注。本文重点评述了纳米碳管在环境样品前处理特别是在固相萃取和固相微萃取方面的研究现状与应用进展,并对纳米碳管的应用前景进行了展望。  相似文献   
204.
通过现场调查、工程分析,对油气田管道工程施工主要工艺环节、施工期间生产环境和劳动过程中存在的职业病危害因素进行识别,并从工程技术、职业卫生管理、个人防护和应急救援方面提出相应的防护措施,对保护管道施工期间劳动者健康具有重要意义。  相似文献   
205.
Cadmium solubility and sorption in an arable clay loam soil that had received sewage sludge for 41 years were compared to an unsludged control in batch studies. Soil pH dominated Cd sorption, explaining >92% of the variation in Kd values in both treatments. At any pH, Cd sorption was apparently slightly but significantly (p < 0.05) smaller in the sludge-amended soil compared to the control, even though the organic carbon content was 70% larger and the ammonium oxalate-extractable iron content was roughly doubled. Correction for dissolved organic carbon (DOC) complexation with the speciation model WHAM reduced the difference in sorption between treatments, but the sludged soil still had significantly smaller Kd values (p < 0.01). Batch equilibrations without addition of Cd showed that there was no significant difference in the solubility of "native" cadmium (defined as EDTA-extractable Cd) in sludged and control soils. The reason for the lack of increase in Cd sorption in the sludge-amended soil has not been established, but it may be due to competition for sorption sites on humic compounds with sludge-derived Fe and trace metals such as zinc. The fact that the pyrophosphate-extractable (i.e., organically associated) iron content was seven times larger in the sludged soil provides some supporting evidence for this hypothesis.  相似文献   
206.
207.
我国湖泊富营养化问题及防治对策   总被引:25,自引:0,他引:25  
史丹 《资源开发与市场》2005,21(1):17-18,27
富营养化是我国湖泊的主要问题,它不但制约了湖泊资源的可利用性,而且直接影响到人类的健康生存与社会经济的持续发展.分析了我国湖泊富营养化的现状、危害、产生的原因,提出了防治对策.  相似文献   
208.
通过采用相关年份有关城市方面的资料,从城市化水平,城市数量、体系和空间分布,城市社会经济发展状况,城市设施水平和城市经济效益5个方面,比较分析了我国三大地区城市发展现状,总结了我国三大地区的特征和城市发展差异,指出今后要积极缩小三大地区间的城市发展差距,推进区域经济的协调发展和可持续发展.  相似文献   
209.
随着近些年振动试验技术的快速发展,对于振动试验数据的保存、管理和统计提出了更高的要求。鉴于此,附属于试验室信息管理系统的振动试验数据管理系统作为振动试验有效的管理工具,必然会成为提升试验室振动试验能力、规范试验技术的有效工具。  相似文献   
210.
Balanced reciprocal translocation is one of the known causes of recurrent spontaneous abortions. Cytogenetic studies of unbalanced miscarriages are difficult due to the growth failure of early loss and usually macerated abortions. We present a molecular study of an abortion in which the father carries a balanced reciprocal translocation t(2;17)(q32.1;q24.3) using QF-PCR and CGH techniques. DNA analysis showed the presence of a trisomy 2 due to a 3:1 interchange segregation. Recombinant events could also be investigated by comparing DNA samples from the family. We propose QF-PCR in addition to CGH as an efficient diagnostic method to improve our knowledge of unbalanced offspring in balanced translocation carriers. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
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