Provenance of Upper Devonian clastic (meta)sediments of the Böllstein Odenwald (Mid-German-Crystalline-Zone,Variscides)     

Dörr  Wolfgang  Zulauf  Gernold  Gerdes  Axel  Loeckle  Filip 《International Journal of Earth Sciences》2017,106(8):2927-2943

International Journal of Earth Sciences - Detrital zircons separated from paragneisses of the northern Böllstein Odenwald (Mid-German Crystalline Zone, Variscides) yielded Cambrian to Upper...  相似文献   

Are long-period body wave coda caused by lateral heterogeneity?     

Filip Neele  Roel Snieder 《Geophysical Journal International》1991,107(1):131-153

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The robust detection of stars on CCD images     

Filip Hroch 《Experimental Astronomy》1999,9(4):251-259

Two parameters are developed to analyze the CCD images from ground-based and/or space telescopes. The first parameter, deduced from the intensity profile of the object sharp, is useful to resolve stars and hot pixels. The second parameter shape distinguishes the stars from the background cosmic-ray events using geometric characteristics defined by its shapes. The parameters are applied to a simulated OMC/INTEGRAL image and a HST image.  相似文献   

Orthotropic anisotropy: on contributions of elasticity parameters to a difference in quasi-P-wave-squared velocities resulted from propagation in two orthogonal symmetry planes     

Filip P. Adamus 《Geophysical Prospecting》2020,68(8):2361-2378

We investigate the dependence of quasi P-wave phase velocity propagating in orthotropic media on particular elasticity parameters. Specifically, due to mathematical facilitation, we consider the squared-velocity difference, , resulted from propagation in two mutually perpendicular symmetry planes. In the context of the effective medium theory, may be viewed as a parameter evaluating the influence of cracks – embedded in the background medium – parallel to one or both aforementioned planes. Our investigation is both theoretical and numerical. Based on Christoffel's equations, we propose two accurate approximations of . Due to them, we interpret the aforementioned squared-velocity difference as being twice more dependent on , than on . To describe the magnitude of the dependence, we consider the proportions between the partial derivatives of . Further, it occurs that is influenced by the ratio of vertically propagating quasi P-wave to vertically propagating quasi S-wave. Anomalously high might be caused by the low P/S ratio, which in turn can be an indicator of the presence of gas in natural fractures or aligned porosity. Also, we carry out numerical sensitivity study, according to which is approximately twice more dependent on than on , twice more sensitive to than to , and equally dependent on as on . The dependence on and can be neglected, especially for small phase angles. We verify the approximations and perform the sensitivity study, using eight examples of the elasticity tensors.  相似文献   

Geochemical and mineralogical control on the mobility of arsenic in a waste rock pile at Dlouhá Ves,Czech Republic     

E. Kocourková  O. Sracek  S. Houzar  J. Cempírek  Z. Losos  J. Filip  P. Hršelová 《Journal of Geochemical Exploration》2011

A waste rock pile with initial high sulfide (10–20 wt.%) and low carbonate content (1–2 wt.%) located at Dlouhá Ves in the Czech Republic has been investigated in two profiles (excavation and outcrop) using powder X-ray diffraction, electron microprobe analysis, bulk composition analysis and Mössbauer spectroscopy. The mobility of arsenic and other contaminants was evaluated by leaching experiments. The primary source of the arsenic was arsenopyrite, which was significantly oxidized in both profiles. The principal As-bearing phase at the excavation profile was goethite, located at the top of the profile, and minerals of the jarosite group which were found down to its base. Melanterite, rich in copper and zinc, was found in a sulfide-rich, lower part of the profile together with anglesite. At the outcrop profile, minerals of the jarosite–beudantite group, scorodite and kaňkite prevail and no Fe(II)-minerals were found. The paste pH was lower at the excavation profile (minimum about 1.9) than at the outcrop profile (minimum of about 2.8). Processes in the pile are affected by the pyrite/arsenopyrite ratio, where high pyrite content decreases the As/S ratio and results in the formation of jarosite group minerals and low pH conditions. Where arsenopyrite predominates, sulphides are coated by scorodite and other Fe–As phases like schwertmannite, which limit their further oxidation.  相似文献   

The effect of acquisition error and level of detail on the accuracy of spatial analyses     

Filip Biljecki  Gerard B.M. Heuvelink  Hugo Ledoux  Jantien Stoter 《制图学和地理信息科学》2018,45(2):156-176

There has been a great deal of research about errors in geographic information and how they affect spatial analyses. A typical GIS process introduces various types of errors at different stages, and such errors usually propagate into errors in the result of a spatial analysis. However, most studies consider only a single error type thus preventing the understanding of the interaction and relative contributions of different types of errors. We focus on the level of detail (LOD) and positional error, and perform a multiple error propagation analysis combining both types of error. We experiment with three spatial analyses (computing gross volume, envelope area, and solar irradiation of buildings) performed with procedurally generated 3D city models to decouple and demonstrate the magnitude of the two types of error, and to show how they individually and jointly propagate to the output of the employed spatial analysis. The most notable result is that in the considered spatial analyses the positional error has a much higher impact than the LOD. As a consequence, we suggest that it is pointless to acquire geoinformation of a fine LOD if the acquisition method is not accurate, and instead we advise focusing on the accuracy of the data.  相似文献   

Multidisciplinary research of landslide at UNESCO site of Lower Hodruša mining water reservoir     

Martin Bednarik  René Putiška  Ivan Dostál  Rudolf Tornyai  Karel Šilhán  Filip Holzer  Karol Weis  Ivan Ružek 《Landslides》2018,15(6):1233-1251

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Spatial analysis of high-resolution urban thermal patterns in Vojvodina,Serbia     

Dušan Jovanović  Miro Govedarica  Filip Sabo  Dubravka Sladić  Aleksandar Ristić 《国际地球制图》2015,30(5):483-505

Main objective of this study was to establish a relationship between land cover and land surface temperature (LST) in urban and rural areas. The research was conducted using Landsat, WorldView-2 (WV-2) and Digital Mapping Camera. Normalised difference vegetation index and normalised difference built-up index were used for establishing the relation between built-up area, vegetation cover and LST for spatial resolution of 30 m. Impervious surface and vegetation area generated from Digital Mapping Camera from Intergraph and WV-2 were used to establish the relation between built-up area, vegetation cover and LST for spatial resolutions of 0.1, 0.5 and 30 m. Linear regression models were used to determine the relationship between LST and indicators. Main contribution of this research is to establish the use of combining remote sensing sensors with different spectral and spatial resolution for two typical settlements in Vojvodina. Correlation coefficients between LST and LST indicators ranged from 0.602 to 0.768.  相似文献   

Was the Black Sea catastrophically flooded in the early Holocene?     

Liviu Giosan  Florin Filip  Stefan Constatinescu 《Quaternary Science Reviews》2009,28(1-2):1-6

A catastrophic flooding of the Black Sea basin was proposed to have occurred during its reconnection to the ocean in the early Holocene. Possible cultural consequences of the flood include the migration of Neolithic farmers from around the Black Sea towards central Europe as well as the creation of flood myths. Stratigraphic and paleo-geomorphologic information from Danube delta aided by radiocarbon ages on articulated mollusks constrain the level in the Black Sea before the marine reconnection to ca 30 m below the present sea level rather than 80 m or lower. If the flood occurred at all, the sea level increase and the flooded area during the reconnection were significantly smaller than previously proposed.  相似文献   

Macroscopic diffusivity in concrete determined by computational homogenization     

Filip Nilenius  Fredrik Larsson  Karin Lundgren  Kenneth Runesson 《国际地质力学数值与分析法杂志》2013,37(11):1535-1551

Effective moisture and chloride ion diffusivity coefficients for concrete are determined by computational homogenization, where concrete is modeled on the mesoscale as a heterogenous three‐phase composite material. By imposing moisture and chloride ion gradients on a representative volume element, effective macroscale properties are obtained through finite element analysis. A parametric study of the effects of the ballast content was carried out. The numerical results correspond well with an estimate of the Hashin–Shtrikman type available in the literature. The computational homogenization strategy proposed here also includes the interfacial transition zone, and its influence on the effective diffusivity coefficients is assessed. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献