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The purpose of this study was to investigate the interacting mechanism between the saltating particles near a channel bed. A three-dimensional real-time flow visualization technique was developed to measure the interparticle collision behaviors during the saltating process. Based on the experimental data, the distribution of the collision points was found to be symmetric. This confirms the assumption that the projections of the collision points onto the reasonable plane are uniformly distributed. A three-dimensional saltating model was also developed. This model produced satisfactory results. The model is able to simulate the continuous saltating trajectories of several particles. The simulated dimensionless saltating height, longitudinal and vertical saltation velocity components were found to increase as the dimensionless particle diameter and the dimensionless flow transport capacity parameter increase, while the simulated lateral saltation velocity component varies inversely with the dimensionless flow transport capacity parameter. A regression equation for the bed load transport rate was also obtained. 相似文献
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花莲寿丰测距网设置至今已有11年的观测成果,观测资料显示,菲律宾海板块一直以西北方向向台湾陆地挤压;1999年“921”集集大地震前两个月,挤压转至正西方向,因此,主压应力对台湾陆地之冲击最大,地震也最强,集集地震后至今所观测的资料显示,挤压方向转至西南方向且压力陆续增加。 相似文献
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由于发生1906,1941,1946,1994和1999年的破坏性地震,对台南盆地的地震构造有了更全面的了解,并对台湾西南部的活动右旋走滑的义竹断裂有了新的看法. 曾熟知的梅山断裂和新化断裂不是独立的地震断裂,它们均属于义竹断裂的分段. 1994年9月16日,震中在台湾海峡、台南盆地边缘的地震,断层面接近东西向.此地震为台南盆地沉降历史过程中,右旋走滑断裂的活动剪裂所导致. 从1941年和1999年地震的主震和微震记录中发现,这些菱形分布的地震图像,象征走滑断裂双轨构造中的压缩区. 基于上述研究及其它资料表明义竹断裂是台湾西南部重要的构造活动带,并具有引发地震的可能性. 相似文献
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R. D. JACOBI 《《地质学报》英文版》2002,76(1):89-99
Semivariogram is applied to fracture data obtained from detailed scanline surveys of nine field sites in western New York, USA in order to investigate the spatial patterns of natural fractures. The length of the scanline is up to 36 m. How both fracture spacing and fracture length vary with distance is determined through semivariogram calculations. In this study, the authors developed a FORTRAN program to resample the fracture data from the scanline survey. By calculating experimental semivariogram, the authors found five different types of spatial patterns that can be described by linear, spherical, reversed spherical, polynomial I (for a<0) and polynomial II (for a>0) models, of which the last three are newly proposed in this study. The well-structured semivariograms of fracture spacing and length indicate that both the location of the fractures and the length distribution within their structure domains are not random. The results of this study also suggest that semivariograms can provide useful infor 相似文献
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