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以地市州为基本经济单元,以1999年主要相对指标为依据,通过综合值测算法,将全省划分为四类经济发展水平不同的地区,对四类地区平均总量指标、相对指标进行了对比分析,并揭示了其空间分布特征,简要分析了各类地区经济发展的条件和方向;以1999年、1978年各地市州GDP为例,对比分析了四川省区域经济不平衡发展的动态性特征。 相似文献
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Peter M. Allen Jeffrey G. Arnold Walter Skipwith 《Journal of the American Water Resources Association》2002,38(5):1477-1492
ABSTRACT: Major erosion of urban stream channels is found in smaller basins in the North Texas study area with contributing drainage areas of less than ten square miles. Within these basins, four basic channel types are identified based on bed and bank lithologies: alluvial banks and bottoms, alluvial banks and gravel bottoms, alluvial banks with rock bottoms, and rock banks with rock bottoms. Most channels (75 percent) have alluvial banks with gravel or rock bottoms. Channel slopes are steep (.38 to.76 percent). Rock consists predominantly of shale and limestone. Channel cross sections are divided into the following four zones based on weathering, scour and entrainment mechanisms: soil zone, slake zone, rock zone and bed material zone. Erodibility of the channels is determined using multiple techniques including reach hydraulics and stream power computations, submerged jet testing, slab entrainment thresholds, and slake durability rates. Procedures are based on both empirical and modeled time series estimates of channel erosion. Field and modeled results support rates of erosion of up to four inches per year. Rates are tied to flow regime, climate, and type of channel bed and banks. 相似文献
126.
Impact scoping is the process of identifying important issues of a proposal and focusing the environmental impact assessment
(EIA) on the high-priority issues. Although impact scoping in one form or another has been inherent to EIA for some time,
documentation of its development and discussion of refinements to impact scoping processes have not been forthcoming. This
article traces the development of impact scoping through time and highlights the need for such processes in EIA. A focused
environmental assessment (FEA) approach to impact scoping that is suitable for implementation in an EIA is presented here
and advantages of its use are delineated. FEA is a three-staged process that encourages impact scoping through progressive
steps including impact identification, assessment and management planning. FEA combines a suite of EIA methods including:
issues matrices, impact hypotheses, valued ecosystem components, and stakeholder participation sessions to effectively integrate
impact scoping with EIA. 相似文献
127.
探讨心理测量在安全科学中的地位和作用,提出将心理测量用于安全科学的必要性,着重论述心理测量运用于安全科学技术领域的可行性和科学性,分析和讨论了安全心理测量在安全领域中的应用前景。 相似文献
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C. Michael York 《Journal of the American Water Resources Association》1971,7(5):920-924
ABSTRACT. Elected officials, technical specialists and the public are talking more about “citizen input” into the decision process, and how the people view a given issue or kind of public service. However, problem definition and valid instruments are needed before we can meaningfully predict or understand public attitude relating to a particular issue or concept. The fluoridation of community water supplies was chosen for the present methodological demonstration. This issue achieves a high level of controversy among many public segments [Crain, Katz and Rosenthal, 1969; Davis, 1959; McNeal, 1957]. By 1950, there was widespread endorsement for a national program relating to controlled water fluoridation. Yet, public acceptance of this particular technological advance has not been very high. 相似文献
129.
针对间歇式加煤锅炉在烟尘实际测试中,最终测试结果容易出现误差的问题,通过试验,分析造成误差的主要原因和规律,提出了消除和减小误差的相应对策 相似文献
130.
环境水样阴离子表面活性剂光度测定法 总被引:2,自引:0,他引:2
杨四海 《中国环境管理干部学院学报》1999,(4)
本文通过实验研究,提出了对河水及生活废水阴离子表面活性剂的水相直接测定方法,此方法具有简便、快速的特点,且有良好的准确性和再现性。 相似文献