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51.
在工程建设中,工地及邻近地区的断层活动性是工程设计的一项重要依据。在总结以往研究的基础上,介绍了显微构造分析法和包裹体方法在断层活动性评价中的国内外最新研究成果。事实表明,这两种方法在工程地质领域具有良好的应用前景。 相似文献
52.
1995年全世界发生197次6级以上地震,其中有30次7级以上的地震(最大震级8.1级)。具有灾害性的地震为33次,伤亡20人以上的,国内及边界地区为4次,国外有15次,其中有2次灾难性的大地震。该年地震与1994年相比呈明显增强趋势,为本世纪以来第三个强震最多之年。1995年世界地震灾害的主要特点为地震袭击现代化大城市,造成惨重的人员伤亡,惊人的财产损失数额。 相似文献
53.
A pedagogic problem in forestry and landscape management is to visualize future landscape effects of forest growth and current management activities in the forest. This paper presents a method for forecasting digital image projections of forest landscape dynamics. Static nonlinear regression functions estimate the digital numbers in a Landsat Thematic Mapper image. Regressors used are forest stand variables. By estimating the future forest stand data, based on intermediate treatment and growth, future satellite digital images are created. In a case study example, the future landscape of a forest block in the province of Västernorrland, Sweden, is projected to demonstrate the application of this visualization technique. 相似文献
54.
如何进行英语口语的教学已成为教学界一个非常重要的问题。当前口语教学面临着诸多困难和问题。论文中提及了与口语教学有关的教学法一交际教学法,两个影响口语教学的重要因素,即教与学之间的互动作用和课堂气氛对口语教学的影响。 相似文献
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从道路交通事故统计分析对比谈预防措施 总被引:11,自引:11,他引:11
笔者通过对比我国与世界上部分发达国家近十年来在道路交通事故方面的统计数据 ,并根据经济发展水平与机动车保有量的正比例关系及当前我国道路交通事故现状 ,分析得出道路交通安全事故的发生 ,与人、车辆、道路、环境信息及管理等因素具有密切关系 ,其中人 (尤其是驾驶员 )作为交通行为的主体 ,是道路交通事故诱因中一个关键性因素。由此 ,作者提出了要有效预防和减少道路交通事故的发生 ,必须将人、车、路、环境信息和管理等诸因素作为一个有机整体系统思考 ,且在未来的道路交通发展中应引入交通稳静化理念 ,以实现道路交通的安全、畅通与高效 相似文献
59.
Gregory F. Mclsaac Matthew B. Short George Groschen Paul Terrio 《Journal of the American Water Resources Association》2004,40(2):443-459
ABSTRACT: Long term data on surface water quality can sometimes be assembled by combining data collected by different agencies at different times and assuming that between agency differences in data quality are insignificant. The objective of this paper was to assess the quality of riverine nitrate (NO3) concentrations in Illinois measured and reported by four agencies from 1967 to 1974 by comparing median values for similar sampling locations and periods. A total of 17 river reaches were identified for which two agencies reported NO3 concentrations during similar periods. Nonparametric comparison of median values and analysis of covariance with discharge as a covariant produced similar results. Nitrate concentrations reported by the U.S. Geological Survey (USGS) from 1967 to 1971 were not statistically (P > 0.05) different from values reported by the Illinois State Water Survey (ISWS) for two of three river reaches. Additionally, NO3 concentrations reported by USGS from 1972 to 1974 were not statistically different than concentrations reported by the Illinois Environmental Protection Agency (IEPA) for four of five river reaches. From 1969 to 1971, NO3 concentrations reported by the Illinois Department of Public Heath and the Illinois Environmental Protection Agency (IDPH/IEPA) were less than one‐fourth the magnitude of values reported by ISWS. The median NO3 concentrations measured by the Central Illinois Public Service (CIPS) were significantly greater than those measured by USGS and IDPH/IEPA in the three comparable sampling locations. The use of NO3 concentrations measured by CIPS and IDPH/IEPA prior to 1972 is not recommended. 相似文献
60.
Ashu Jain Lindell E. Ormsbee 《Journal of the American Water Resources Association》2004,40(6):1617-1630
ABSTRACT: This paper presents the findings of a study aimed at evaluating the available techniques for estimating missing fecal coliform (FC) data on a temporal basis. The techniques investigated include: linear and nonlinear regression analysis and interpolation functions, and the use of artificial neural networks (ANNs). In all, seven interpolation, two regression, and one ANN model structures were investigated. This paper also investigates the validity of a hypothesis that estimating missing FC data by developing different models using different data corresponding to different dynamics associated with different trends in the FC data may result in a better model performance. The FC data (counts/100 ml) derived from the North Fork of the Kentucky River in Kentucky were employed to calibrate and validate various models. The performance of various models was evaluated using a wide variety of standard statistical measures. The results obtained in this study are able to demonstrate that the ANNs can be preferred over the conventional techniques in estimating missing FC data in a watershed. The regression technique was not found suitable in estimating missing FC data on a temporal basis. Further, it has been found that it is possible to achieve a better model performance by first decomposing the whole data set into different categories corresponding to different dynamics and then developing separate models for separate categories rather than developing a single model for the composite data set. 相似文献