Random multistage input and energy partition approach to the description of cavitation erosion process     

Boleslaw G. Giren  Janusz Steller 《Stochastic Environmental Research and Risk Assessment (SERRA)》2009,23(3):263-273

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Correlation between Loess profiles on the basis of mineralogical,malacological, and anthropogenic indicators: A case study from Moravany-Lopata,western Slovakia     

Maciej Pawlikowski  Witold P. Alexandrowicz  Ladislav Banesz  Josef Hromada  Janusz K. Kozlowski  Krzysztof Sobczyk  Barbara Kazior 《Geoarchaeology》1998,13(6):565-594

Moravany-Lopata, located in the complex of sites in the middle Vah basin, dates to the period immediately preceding the LGM. The authors use this site to demonstrate the usefulness of mineralogical, sedimentological, palaeomalacological, and anthropogenic criteria for the correlation of loess profiles. This analysis is especially concerned with sites in loess territories where the loess layers covering archaeological levels are not thick. Such sites occur frequently on the plateaus of the northern part of Central Europe, though they appear most notably in the areas in which the last loess cover, corresponding to the period after the last Pleniglacial and/or Late Glacial postloess sediments, is absent. The archaeological levels dated to before or directly after the LGM occur in the upper portion of the loess, overlain by the Holocene soil. The investigations at the Moravany-Lopata site have confirmed the usefulness of the anthropogenic indicators in the 0.1–1.0 mm fraction for the identification of occupation levels extending even beyond the area of occurrence of macrofinds and evident type structures. On this basis, a relationship could be established between two occupational levels and two ice-wedge generations in the period from 21.4 to 20 ky. Gravettian settlement in western Slovakia seems to have persisted up to the maximum of the LGM. Population groups representing the end of the shouldered points horizon (pointes à cran) appeared in western Slovakia in the intervals between the formation of large networks of ice wedges. The next settlement phase in that territory falls at about 18–17 ky B.P. This is the Epigravettian settlement, which is culturally unrelated to the shouldered points horizon. © 1998 John Wiley & Sons, Inc.  相似文献   

OSL‐based chronostratigraphy of river terraces in mountainous areas,Dunajec basin,West Carpathians: a revision of the climatostratigraphical approach          下载免费PDF全文

Janusz Olszak  Grzegorz Adamiec 《Boreas: An International Journal of Quaternary Research》2016,45(3):483-493

The technique of optically stimulated luminescence (OSL) dating applied to fluvial sediments provided a geochronological framework of river terrace formation in the middle part of the Dunajec River basin – a reference area for studies of evolution of river valleys in the northern part of the Carpathians (West Carpathians). Fluvial sediments at 18–90 m above valley bottoms were dated in the valleys of the Dunajec River and one of its tributaries. The resulting ages range from 158.9±8.3 to 12.2±1.3 ka. This indicates that some of the terrace sediments were deposited much later than previously assumed on the grounds of a combined morphostratigraphical and climatostratigraphical approach. The OSL‐based chronostratigraphy of terrace formation consists of seven separate phases of fluvial aggradation, separated by periods of incision and lateral erosion. Some of the ages determined correspond to warm stages of the Pleistocene – Marine Isotope Stage 3 (MIS 3) and MIS 5 – demonstrating that some terraces were formed during interstadial or interglacial periods. The results provide a key for evaluating rates of neotectonic uplift, allowing us to decipher the response of a fluvial system to climate change within the context of the glacial–interglacial scheme.  相似文献   

A microphysically-based approach to modeling emissivity and albedo of the martian seasonal caps     

Janusz Eluszkiewicz  Jean-Luc Moncet  Gary B. Hansen 《Icarus》2005,174(2):524-534

A new model of albedo and emissivity of the martian seasonal caps represented as porous CO₂ slabs containing spherical voids and dust particles is described. In the model, a radiative transfer model is coupled with a microphysical model in order to link changes in albedo and emissivity to changes in porosity caused by ice metamorphism. The coupled model is capable of reproducing temporal changes in the spectra of the caps taken by the Thermal Emission Spectrometer onboard the Mars Global Surveyor and it can be used as the forward model in the retrievals of the caps' physical properties (porosity, dust abundance, void and dust grain size) from the spectra. Preliminary results from such inversion studies are presented.  相似文献   

Morphology and evolution of simulated and optical clusters: a comparative analysis     

Nurur Rahman †‡  Janusz Krywult  Patrick M. Motl  Piotr Flin  Sergei F. Shandarin 《Monthly notices of the Royal Astronomical Society》2006,367(2):838-850

We have made a comparative study of morphological evolution in simulated dark matter (DM) haloes and X-ray brightness distribution, and in optical clusters. Samples of simulated clusters include star formation with supernovae feedback, radiative cooling and simulation in the adiabatic limit at three different redshifts,   z = 0.0, 0.10  and 0.25. The optical sample contains 208 Abell, Corwin & Olowin (ACO) clusters within redshift,   z ≤ 0.25  . Cluster morphology, within 0.5 and 1.0 h ⁻¹ Mpc from cluster centre, is quantified by multiplicity and ellipticity.
We find that the distribution of the DM haloes in the adiabatic simulation appears to be more elongated than the galaxy clusters. Radiative cooling brings halo shapes in excellent agreement with observed clusters; however, cooling along with feedback mechanism makes the haloes more flattened.
Our results indicate relatively stronger structural evolution and more clumpy distributions in observed clusters than in the structure of simulated clusters, and slower increase in simulated cluster shapes compared to those in the observed one.
Within   z ≤ 0.1  , we note an interesting agreement in the shapes of clusters obtained from the cooling simulations and observation. We also note that the different samples of observed clusters differ significantly in morphological evolution with redshift. We highlight a few possibilities responsible for the discrepancy in morphological evolution of simulated and observed clusters.  相似文献   

X-ray Flare Spectra from the DIOGENESS Spectrometer and Its Concept Applied to ChemiX on the Interhelioprobe Spacecraft     

Janusz Sylwester  Zbigniew Kordylewski  Stefan Płocieniak  Marek Siarkowski  Mirosław Kowaliński  Stanisław Nowak  Witold Trzebiński  Marek Śtęślicki  Barbara Sylwester  Eugeniusz Stańczyk  Ryszard Zawerbny  Żaneta Szaforz  Kenneth J. H. Phillips  František Fárník  Anatolyi Stepanov 《Solar physics》2015,290(12):3683-3697

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The Main Ostrava Whetstone: composition, sedimentary processes, palaeogeography and geochronology of a major Mississippian volcaniclastic unit of the Upper Silesian Basin (Poland and Czech Republic)     

Jakub Jirásek  Lada Hýlová  Martin Sivek  Janusz Jureczka  Karel Martínek  Ivana Sýkorová  Mark Schmitz 《International Journal of Earth Sciences》2013,102(4):989-1006

The Main Ostrava Whetstone (MOW) is an important lithostratigraphic horizon of the Late Carboniferous sedimentary fill of the late Palaeozoic foreland Upper Silesian Basin. It is the largest and best-identified volcanogenic horizon in the basin, reaching thicknesses of 15.3 m and occupying an area of ca 2,973 km² and a volume after lithification of 9.24 km³. It consists of volcanic materials transported to the basin probably by an aeolian process. Just after sedimentation, these materials were redeposited a short distance away in a shallow water environment. Granularity corresponds to a range from argillaceous siltstones to fine-grained sandstones. The components are dominated by glass shards replaced by clay minerals (mixed illite–smectite structures) in addition to quartz of volcanogenic and terrigenous origins. Sanidine and a plagioclase close to albite are also present. The sedimentary structures, micro-structures and composition of the MOW indicate variable and dynamic hydrodynamic conditions. The MOW represents a series of flooding events, which could be connected with unusual rainfall. Such major flooding events were most likely induced by volcanic eruptions. The available drill-core log data were used to construct a digital model of the whetstone, which showed an east–west zonality in the thicknesses, with the majority being synsedimentary. CA-TIMS U–Pb dating the volcanogenic zircons yields an age of 327.35 ± 0.15 Ma. The source location of the volcanogenic material is not clear; however, it is presumed to have been located in the west of the Upper Silesian Basin.  相似文献   

GPS-derived height changes in diurnal and sub-diurnal timescales   总被引：1，自引：0，他引：1  

Janusz Bogusz  Mariusz Figurski 《Acta Geophysica》2012,60(2):295-317

This paper describes the research concerning precise short-time GPS solutions conducted in the Centre of Applied Geomatics, Military University of Technology, Warsaw, Poland. The data from ASG-EUPOS (Polish Active Geodetic Network) was processed using Bernese 5.0 software and EPN (EUREF Permanent Network) standards and models. In this study, the adapted 3-hour observation window is shifted every hour for obtaining hourly geocentric coordinates in ITRF2005 reference frame. The adjusted network consisted of over 130 stations from Poland and the neighbouring countries, the period covered observations collected from June 2008 through June 2010. These two years of observations allowed for examining short-period oscillations which were found to be closely related to the tidal (dynamic) frequencies. The analysis of the residua from the IERS2003 tidal model was performed using the least squares method with the Eterna software. It confirmed the existence of significant (several millimetres) oscillations in the frequencies corresponding to S1, K1 and K2. The paper describes the idea of data processing and analysis, presents the results of vertical (the Up component) oscillations in main tidal frequency bands, and also includes discussion of possible explanation of the existence of short-period oscillations in the GPS precise solutions and the possibility of propagation of short-period oscillations into long-period spurious changes in the daily (standard) GPS solutions.  相似文献   

Scenarios of the spread of a waste heat discharge in a river — Vistula River case study     

Monika B. Kalinowska  Paweł M. Rowiński  Janusz Kubrak  Dorota Mirosław-Świątek 《Acta Geophysica》2012,60(1):214-231

The problem of two-dimensional mathematical modelling of heated cooling water discharges into running waters is considered in the paper. Two models — one for the evaluation of 2D turbulent velocity field and the other, developed by authors of the study, for 2D heat transport in open-channels — were used in the calculations. Relevant scenarios of the spread of heated water discharged from a designed gas-stem power plant to be constructed at the Vistula River were presented. Environmentally most friendly variant of the discharge of the thermal pollution was selected from among four various variants.  相似文献   

Fast direct GPS P-Code acquisition   总被引：5，自引：0，他引：5  

Jing?PangEmail author  Frank?Van?Graas  Janusz?Starzyk  Zhen?Zhu 《GPS Solutions》2003,7(3):168-175

GPS P-Code has a higher chipping rate, better accuracy, and anti-jamming property than C/A code. Traditionally, GPS P-Code acquisition depends on handover from C/A code. This potentially needs long acquisition time. Moreover, when C/A code is not available, it is no longer possible to acquire GPS P-Code through handover from C/A code. The purpose of this paper is to describe a new overlap average method to facilitate hardware design of fast direct P-Code acquisition. It allows the rapid code phase search to acquire GPS P-Code signals, and also decreases the hardware resource requirement. The small size FFT in the proposed methods is very promising for fast FPGA hardware system design using FFT cores. The simulation results and theoretical analysis are included demonstrating the overall performance of the proposed method.

Jing PangEmail: Phone: +1-916-2784549Fax: +1-916-2787215

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