Hydroacoustic analysis of spatial and temporal variability of bottom sediment characteristics in Lake Kinneret in relation to water level fluctuation   总被引：1，自引：1，他引：0  

Ilia Ostrovsky  Jarosław Tęgowski 《Geo-Marine Letters》2010,30(3-4):261-269

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Search for GRB related prompt optical emission and other fast varying objects with “Pi of the Sky” detector     

M. Ćwiok  W. Dominik  K. Małek  L. Mankiewicz  J. Mrowca-Ciułacz  K. Nawrocki  L. W. Piotrowski  P. Sitek  M. Sokołowski  G. Wrochna  A. F. Żarnecki 《Astrophysics and Space Science》2007,309(1-4):531-535

Experiment “Pi of the Sky” is designed to search for prompt optical emission from GRB sources. 32 CCD cameras covering 2 steradians will monitor the sky continuously. The data will be analysed on-line in search for optical flashes. The prototype with 2 cameras operated at Las Campanas (Chile) since 2004 has recognised several outbursts of flaring stars and has given limits for a few GRB.  相似文献   

The importance of interloper removal in galaxy clusters: saving more objects for the Jeans analysis     

Rados&#;aw Wojtak  Ewa L. &#;okas 《Monthly notices of the Royal Astronomical Society》2007,377(2):843-854

We study the effect of contamination by interlopers in kinematic samples of galaxy clusters. We demonstrate that without the proper removal of interlopers the inferred parameters of the mass distribution in the cluster are strongly biased towards higher mass and lower concentration. The interlopers are removed using two procedures previously shown to work most efficiently on simulated data. One is based on using the virial mass estimator and calculating the maximum velocity available to cluster members and the other relies on the ratio of the virial and projected mass estimators. We illustrate the performance of the methods in detail using the example of A576, a cluster with a strong uniform background contamination, and compare the case of A576 to 15 other clusters with different degree of contamination. We model the velocity dispersion and kurtosis profiles obtained for the cleaned data samples of these clusters solving the Jeans equations to estimate the mass, concentration and anisotropy parameter. We present the mass–concentration relation for the total sample of 22 clusters.  相似文献   

A Review of Cometary Outbursts at Large Heliocentric Distances     

P. Gronkowski  M. Wesołowski 《Earth, Moon, and Planets》2016,117(1):23-39

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Variability of high rainfalls and related synoptic situations causing heavy floods at the northern foothills of the Tatra Mountains     

Tadeusz Niedźwiedź  Ewa Łupikasza  Iwona Pińskwar  Zbigniew W. Kundzewicz  Markus Stoffel  Łukasz Małarzewski 《Theoretical and Applied Climatology》2015,119(1-2):273-284

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Comparison of P- and S-waves velocities estimated from Biot-Gassmann and Kuster-Toksöz models with results obtained from acoustic wavetrains interpretation     

Maria BałA  Adam Cichy 《Acta Geophysica》2007,55(2):222-230

Kuster-Toksöz and Biot-Gassmann models for estimating velocities of longitudinal and shear waves on the basis of well-logging data were analysed. P-wave and S-wave velocity models are crucial for interpretation of seismic data. Discussed models enable determination with quite good accuracy, in some cases higher than the acoustic full wavetrains interpretation. Because velocity strongly depends on lithology and saturation of pore space, the selection of parameters of rock matrix, hydrocarbons and formation waters has a strong effect on the quality of velocities estimation.  相似文献   

Types of sedimentary environment in alluvial sediments distinguished on the basis of its chemical constitution: the example of the lower course of the Obra river (Western Poland)   总被引：1，自引：1，他引：0  

Marcin Słowik  Tadeusz Sobczyński  Zygmunt Młynarczyk 《Environmental Earth Sciences》2010,59(5):957-966

Research concerning chemical constitution of alluvial sediments was done in the lower course of the Obra river (Western Poland). The fragment of vertical profile, which consisted of various alluvial sediments (fine sands, peats, and sandy silts) was chosen for detailed analysis. The main research problem was to determine if lithology and chemical constitution of alluvial deposits are interconnected in a distinct way within studied section of the Obra river valley, and, if changes of chemical elements’ concentration could be used to illustrate depositional processes, which take place in riverbed and floodplain. Concentrations of Fe, Mn, Cu, Zn, Ca, Mg, and K were determined in collected sediment samples. Next, geochemical groups of alluvial sediments were distinguished using cluster analysis. Investigated changes of chemical elements’ concentration show that there is a distinct border between the environment of organic sediments, which marks the place of former functioning of the Obra riverbed, and sandy silts, which were deposited within floodplain during floods. Besides, floodplain sediments, riverbed sediments, and reductive environment within peat deposits were singled out on the basis of the analysis.  相似文献   

Simulation of an uncertain emission market for greenhouse gases using agent-based methods     

Zbigniew Nahorski  Jarosław Stańczak  Piotr Pałka 《Climatic change》2014,124(3):647-662

The paper presents the problem of a simulation of the greenhouse gases emission permits market where only low accuracy emission amounts are known. An organization of the market with uncertain emissions is proposed and trading rules for individual market participants are discussed. Simulation of the market is based on a multi-agent system. Negotiation of purchase/sale prices between the parties are introduced, where the trading parties adopt one of two options: (i) bilateral negotiations, and (ii) sealed bid reverse auctions. Results of simulation runs show trajectories of transaction prices, as well as probability distributions of learning agents’ bidding prices.  相似文献   

From Cadomian arc to Ordovician passive margin: geochemical records preserved in metasedimentary successions of the Orlica-Śnieżnik Dome in SW Poland     

Jacek Szczepański  Sławomir Ilnicki 《International Journal of Earth Sciences》2014,103(3):627-647

The chemical composition of metamorphosed siliciclastic rocks in the Orlica-?nie?nik Dome (Bohemian Massif) identifies the main sources for the Neoproterozoic [the M?ynowiec Formation (MF)], Early Cambrian [the Stronie Formation (SF)] and Late Cambrian/Early Ordovician [the Goszów quartzites (GQ)] sediments. The MF developed from erosion of a Cadomian magmatic arc along the northern Gondwana margin. The variegated SF, with supra-subduction affinities, shows chemical characteristics pointing to erosion of the freshly exhumed Cadomian orogen and detritus deposition in the back-arc basin. The very different chemical features of the GQ indicate deposition in a basin sited on a passive continental margin. The explanation proposed for the observed changes in chemical composition involves three main stages: (1) The pre ~540 Ma evolution of an active continental margin and related back-arc basin ceased with the collision and accretion of the magmatic arc to the Gondwana margin; (2) Early Cambrian rift to drift transition (540–500 Ma) and development of a depositional basin filled with detritus derived from remnants of the magmatic arc; (3) Peri-Gondwana break-up leading to the formation of shallow-water passive margin depositional basins filled with quartz-rich detritus resembling Early Ordovician Armorican quartzites known from other parts of the Variscan Belt.  相似文献   

Analysis of labile form of aluminum and heavy metals in bottom sediments from Kongsfjord, Isfjord, Hornsund fjords     

Marcin Frankowski  Anetta Zioła-Frankowska 《Environmental Earth Sciences》2014,71(3):1147-1158

The paper presents study results obtained for the bottom sediment samples of fjords Kongsfjord, Isfjord, Hornsund in the form of surface samples and their core profiles. The concentrations of labile form of aluminum and heavy metals were determined using the single-stage extraction with 3 mol L^?1 HCl. The obtained results allowed defining the occurrence of variability of labile aluminum form in the samples of bottom sediments of the studied fjords depending on the point and depth of sample collection. The conducted chemometric analysis allowed for the study of spatial variability of aluminum occurrence in the area of the investigated fjords. Based on the analysis, the correlations between aluminum and heavy metals were determined.  相似文献