The soilmodels.info project   总被引：1，自引：0，他引：1  

Gerd Gudehus  Angelo Amorosi  Antonio Gens  Ivo Herle  Dimitrios Kolymbas  David Mašín  David Muir Wood  Andrzej Niemunis  Roberto Nova  Manuel Pastor  Claudio Tamagnini  Gioacchino Viggiani 《国际地质力学数值与分析法杂志》2008,32(12):1571-1572

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A novel time-series station in the Wadden Sea (NW Germany): First results on continuous nutrient and methane measurements     

Maik Grunwald  Olaf Dellwig  Gerd Liebezeit  Bernhard Schnetger  Rainer Reuter  Hans-Jürgen Brumsack 《Marine Chemistry》2007

In autumn 2002 a time-series station was installed in the tidal inlet between the Islands of Langeoog and Spiekeroog (Southern North Sea, NW Germany) to continuously measure physical, chemical, and meteorological parameters, even during extreme weather conditions (gale-force storms, drifting ice). Inside the pole of the station sensor tubes are installed in direction of the prevailing tidal currents. The tubes are equipped with hydrographic sensors (pressure, temperature, conductivity) and allow retrieval of water for nutrient analysis by automated instruments located inside the pole. Dissolved methane and the nutrients ammonia, nitrite, nitrate, phosphate, and silicate are measured at the station.  相似文献   

Baltic cod recruitment - the impact of climate variability on key processes   总被引：3，自引：0，他引：3  

Koster  Friedrich W.; Mollmann  Christian; Hinrichsen  Hans-Harald; Wieland  Kai; Tomkiewicz  Jonna; Kraus  Gerd; Voss  Rudiger; Makarchouk  Andrei; MacKenzie  Brian R.; St. John  Michael A.; Schnack  Dietrich; Rohlf  Norbert; Linkowski  Tomasz; Beyer  Jan E. 《ICES Journal of Marine Science》2005,62(7):1408-1425

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The northwest european shelf temperature and salinity variability     

Gerd A. Becker  Alexander Frohse  Peter Damm 《Ocean Dynamics》1997,49(2-3):135-151

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In-plane and anti-plane strong shaking of soil systems and structures     

G. Gudehus  R. O. Cudmani  A. B. Libreros-Bertini  M. M. Bühler 《Soil Dynamics and Earthquake Engineering》2004,24(4):319-342

The concept of in-plane and anti-plane shaking is introduced with a rigid block on a plane surface with Coulomb friction. Using a hypoplastic constitutive relation to model the mechanical behaviour of the soil, numerical solutions for a rigid block on a thin dry or saturated soil layer are obtained. The coupled nature of dynamic problems involving granular materials is shown, i.e. the motion of the block changes the soil state—skeleton stresses and density—which in turn affects the block motion. Motions of the block as well as soil response can be more realistically calculated by the new model. The same constitutive equation is applied to the numerical simulation of the propagation of plane waves in homogeneous and layered level soil deposits induced by a wave coming from below. Experiments with a novel laminar shake box as well as real seismic records from well-documented sites during strong earthquakes are used to verify the adequacy of the hypoplasticity-based numerical model for the prediction of soil response during strong earthquakes. The response of a homogeneous earth dam subjected to in-plane and anti-plane shaking is investigated numerically. In-plane and anti-plane shaking is shown to cause nearly the same spreading of a sand dam under drained conditions, whereas under undrained conditions anti-plane shaking causes stronger spreading of the dam. The dynamic behaviour of a breakwater founded on rockfill and soft clay during the 1995 Kobe earthquake is back-calculated to show the good performance of the proposed numerical model also with a structure. Section 9 deals with buildings on mattresses of densified cohesionless soils or fine-grained soils with granular columns, slopes with ‘hidden’ dams and structures on piles traversing clayey slopes to show the suitability of hypoplasticity-based models for the earthquake-resistant design and safety assessment of geotechnical systems.  相似文献   

Thermal evolution of an extensional detachment as constrained by organic metamorphic data and thermal modeling: Graz Paleozoic Nappe Complex (Eastern Alps)   总被引：1，自引：0，他引：1  

Gerd Rantitsch  Reinhard F. Sachsenhofer  Christian Hasenhüttl  Barbara Russegger  Thomas Rainer 《Tectonophysics》2005,411(1-4):57-72

Following Early Cretaceous nappe stacking, the Eastern Alps were affected by late-orogenic extension during the Late Cretaceous. In the eastern segment of this range, a Late Cretaceous detachment separates a very low- to low-grade metamorphic cover (Graz Paleozoic Nappe Complex, GPNC) above a low- to high-grade metamorphic basement. Synchronously, the Kainach Gosau Basin (KGB) collapsed and subsided on top of the section.Metamorphism of organic material within this section has been investigated using vitrinite reflectance data and Raman spectra of extracted carbonaceous material. In the southern part of the GPNC, vitrinite reflectance indicates a decrease in organic maturity towards the stratigraphic youngest unit. The remaining part of the GPNC is characterized by an aureole of elevated vitrinite reflectance values and Raman R2 ratios that parallels the margins of the GPNC. Vitrinite reflectance in the KGB shows a steep coalification gradient and increases significantly towards the western basin margin. The observed stratigraphic trend in the southern GPNC is a result of deep Paleozoic to Early Cretaceous burial. This maturity pattern was overprinted along the margins by advective heat and convective fluids during Late Cretaceous to Paleogene exhumation of basement rocks.During shearing, the fault zone was heated up to ca. 500 °C. This overprint is explained by a two-dimensional thermal model with a ramp-flat fault geometry and a slip rate of 1 to 1.5 cm/year during 5 Ma fault movement. The collapse basin above the detachment subsided in a thermal regime which was characterized by relaxing isotherms.  相似文献   

Mechanisms of partly flooded loose sand deposits     

Gerd?GudehusEmail author 《Acta Geotechnica》2016,11(3):505-517

Partly flooded loose sand deposits are left back from lignite mining, particularly in east Germany. After flooding, gas inclusions in macropores enhance the pore pressure increase by total stress cycles without drainage, and this can cause the transition into a kind of suspension. Thus, natural and technical changes of surface loads triggered flow slides in chain reactions of sometimes catastrophic extent. Such collapsible deposits were and are stabilized by blast-induced liquefaction and densification. Successive collapse fronts in flooded grain skeletons are seismogeneous, and this appears as wavering in the near-field and leads to power-law spectra in the far-field. Apart from this evidence of mild fractality, the wild fractality of chain reactions eludes mathematical treatment. Therefore, uncommon methods of geotechnical design, operations and monitoring are required.  相似文献   

Zu den Oberflächentemperaturen der Nordsee von Ende Oktober 1991 bis zur zweiten Junihälfte 1992     

Gerd Wegner 《Ocean Dynamics》1991,44(3):143-151

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Application of a spectral correction method for measurements of covariances with fast-response sensors in the atmospheric boundary layer up to a height of 130 m and testing of the corrections   总被引：1，自引：0，他引：1  

Jürgen Rißmann  Gerd Tetzlaff 《Boundary-Layer Meteorology》1994,70(3):293-305

Measurement of meteorological quantities with fast-response sensors by means of the eddycorrelation technique allows calculation of turbulent transport without too severe demands with regard to stationarity and homogeneity. However, the measurement system causes frequency-dependent errors due to measuring height, averaging interval, sampling rate and mean wind speed. A correction method (Moore, 1986) was applied to measurements taken on a 130 m tower located at the German North Sea coast. The errors for 10-min averages, obtained at a height of 10 m were between 20 and 30%, mainly caused by the inertia of the sensors, increasing to between 30 and 60% at 130 m height due to a loss of low-frequency parts of the spectra because of the averaging interval. The corrections to the obtained data were validated by comparing the cospectra calculated from the data with the spectra used for the computation of the correction factors.  相似文献   

Mineral distribution and feldspar weathering in a saprolite from northeastern Nigeria     

Gerd F. Tietz 《Chemical Geology》1987,60(1-4):163-176

Mineral composition was analysed within a saprolite profile from NE Nigeria. The determination of identifiable feldspar phases is only based on X-ray powder diffractograms. Representative K-feldspar fragments were selected for detailed SEM (scanning electron microscope) studies and EDX (energy-dispersive X-ray analysis) from the profile.

The analytical data indicate a significant contrast in weathering states between the lower and the upper profile section. This contrast reflects a different weathering history: the feldspars from the lower section exhibit weathering features that are characteristic for decomposition below the water table. When raised above the water table, another type of decomposition attacked only the feldspars within the upper section while those in the lower section still preserve the older weathering state.  相似文献