Das Amazonas-Entwässerungssystem in Zeit und Raum     

Professor Dr. Hellmut Grabert 《International Journal of Earth Sciences》1983,72(2):671-683

The history of the Amazon river system is fixed by two geologic main events: the development of the Atlantic Ocean caused by the break up of the Gondwana continent, and the evolution of the Andean orogenesis. On the other hand the direction of the drainage flow is caused by the Amazon Graben in the subsoil. Also the pleistocene glaciation influenced the Amazon drainage system by lowering the sea level as result of ice fixing in polar regions.  相似文献   

A robust algorithm for ellipse-based discrete element modelling of granular materials   总被引：1，自引：0，他引：1  

John M. Ting  Associate Professor 《Computers and Geotechnics》1992,13(3):175-186

With recent research indicating the importance of the rolling mechanism of deformation in granular systems consisting of perfectly round particles, it has become popular to use ellipse-shaped particles in the Discrete Element Method (DEM) numerical model. Inherent in this technique is the need for accurately computing ellipse to ellipse intersection, in order to properly detect contact formation and compute relative contact velocities. However, the commonly used algorithms for computing ellipse-ellipse intersection are generally poorly conditioned and can be inaccurate. An alternate method for computing ellipse-ellipse intersection is developed and presented which results in a well-conditioned, stable and accurate contact detection method. These modification are incorporated into the general DEM algorithm.  相似文献   

NUMERICAL SIMULATION OF TURBIDITY CURRENT IN RESERVOIR     

YU  Wei-Sheng Post-Doctoral Fellow  Hydraulic Research Laboratory  National Taiwan University  Taipei  Taiwan  China LEE  Hong-Yuan Professor  Department of Civil Engineering  National Taiwan University  Taipei  Taiwan  China 《国际泥沙研究》1993,(2)

I. INTRODUCTIONWhen a sediment--laden flow reaches the backwater zone of a reservoir, the suddenreduction of flow velocity causes sediment particles to settle toward the river bed. Undercertain circumstsnces, it will plunge and form a layer of sediment--water mixture flowingbeneath the water surface. This flowing layer is called the turbidity current. A turbiditycurrent is relatively stable and has important impacts on reservoir sedimentation.In the case of deep reservoirs, due to temper…  相似文献   

BED FORMS AND RESISTANCE PROPERTIES OF LIGHT-WEIGHT BED MATERIAL     

WANG Guixian  WANG Xingkui  GUO Jiachao Professor  Sediment Research Laboratory  Dept. of Hydraulic Engineering  Tsinghua University  Beijing  China. Associate Professor  Dept. of Hydraulic Engineering  Tsinghua University. Assistant  Dept. of Hydraulic Engineering  Tsinghua University. 《国际泥沙研究》1993,(3)

I. INTRODUCTIONResistance to flow in alluvial streams is one of the crucial problems in fluvial hydraulics. Despite that large amount of studies have been conducted for centuries, no perfectmethod describing and calculating the resistance to flow in alluvial streams is availablehll now. Investigation on bed forms and resistance properties of light--weight bed materials is even more scarce. USWES (1936) has conducted systematic experiments onlight--weight materials in a flume & m long an…  相似文献   

Wie der Gesundheitsingenieur seine Zusammenarbeit mit dem Biologen sieht     

Prof. W. F. J. M. Krul Professor in Sanitary engineeering 《Aquatic Sciences - Research Across Boundaries》1960,22(1):503-506

Ohne Zusammenfassung  相似文献   

Geophysical results in Austria with special regard to telluric measurements     

Professor Dr. K. Friedl  Professor Dr. K. Kántás 《Pure and Applied Geophysics》1959,43(1):195-208

Summary The paper treats the results of telluric measurements in the Austrian Molasse-Zone and in the Vienna Basin, supplemented with data of other geophysical methods and deep-wells. The analysis of the results shows that the telluric method supplies not only a picture with good reconnaissance proceeding from which further, especially seismic research can be planned more expediently, but can render good services in solving detailed problems too. The hypothesis concerning the anisotropy of sediments resp. its effect is verified by the results of modelexperiments too.

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Zusammenfassung Die Arbeit behandelt die Ergebnisse der Tellurischen Forschungen in der österreichischen Molasse-Zone und im Wiener Becken unter Einbeziehung von Angaben anderer geophysikalischen Messungen und Tiefbohrungen. Die Analyse der Ergebnisse zeigt, dass die tellurische Methode nicht bloss eine gute geophysikalische Übersichtskarte ergibt, von der ausgehend weitere — in der Hauptsache seismische — Forschungen zweckentsprechender geplant werden können, sondern sie leistet auch recht gute Dienste bei der Lösung von Detaiproblemen. Die Hypothese über die Anisotropie der Sedimente bzw. ihr Effekt wurde auch durch die Ergebnisse von Modellversuchen bestätigt.

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Die Genauigkeit der Kornzählanalyse zur Bestimmung des quantitativen Mineralbestandes von kompakten Gesteinen granitähnlieher Zusammensetzung     

Professor Dr. K. R. Mehnert  A. Willgallis  B. Kallies  W. Meier  B. Schüler 《Contributions to Mineralogy and Petrology》1959,6(4):203-218

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THOMPSON-WATTS PLOTTING MACHINE     

Professor  E. H. Thompson 《The Photogrammetric Record》1954,1(3):5-28

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DEDUCTION OF CONSTRAINT CONDITIONS IN THE CALIBRATION OF STEREO-VISION SYSTEN     

FENG Wenhao  Professor  School of Information Engineering  WTUSM  Wuhan  China   《地球空间信息科学学报》1998,(1)

In the test-field calibration,multi-azimuth stereo image pairs areproduced of the outdoor large control-field by the stereo-vision system under cali-bration.While in the analytical processing,the relationship between image pairsis adopted as a constraint condition,which ensures the stability and quality of thecalibration results.This paper introduces the deduction process of the constraintconditions.  相似文献   

A VARIATIONAL METHOD FOR COMPUTING POTENTIAL COEFFICIENTS USING DIFFERENT TYPES OF GRAVIMETRIC DATA     

GUO Junyi  Associate Professor  Laboratory for Modern Geodynamics  WTUSM  Wuhan  China   《地球空间信息科学学报》1998,(1)

In this paper,a variational method is presented for solving theclassical gravimetric,satellite gravimetric and satellite altimetric mixed typeboudary value problem to obtain the potential coefficients.According to thisprinciple,classical gravimetric data（height measured by geometric levelling orheight triangulation）,satellite gravimetric data（height measured by satellitegeodesy technique）and satellite altimetric data can be used jointly to calculate thepotential coefficients.  相似文献