Evaluation of the thermal conductivity of sandstone solid skeleton using the concept of equivalent microstructure     

Łydżba  Dariusz  Różański  Adrian  Sevostianov  Igor  Stefaniuk  Damian 《Acta Geotechnica》2022,17(11):5059-5072

Acta Geotechnica - We evaluate thermal conductivity of the skeleton of porous sandstone from the measurements of the effective thermal conductivities of dry and saturated specimens provided by...  相似文献   

A New Species of Dactylolabis (Eobothrophorus) from Baltic Amber (Diptera:Limoniidae)   总被引：1，自引：1，他引：0  

Wies?aw KRZEMINSKI  Iwona KANIA  and Ewa KRZEMINSKA 《《地质学报》英文版》2010,84(4):768-771

  相似文献   

Eutrophication in the Polish coastal zone: the past, present status and future scenarios     

Łysiak-Pastuszak E  Drgas N  Piatkowska Z 《Marine pollution bulletin》2004,49(3):186-195

In the Baltic Sea eutrophication processes have accelerated in the past 50 years of the 20th century and presently there exists a major ecological problem for this sea. The Polish coastal zone of the southern Baltic Sea is the recipient of riverine inputs from two major sources, namely the Odra and Vistula, as well as a number of smaller rivers along the central coast. Hence, the entire coastal zone remains under severe anthropogenic pressure. The variability of nutrient concentrations, especially the winter nutrient pool in the euphotic zone, summer level of total nitrogen and total phosphorus, together with such eutrophication indicators as water oversaturation with oxygen and the summer oxygen minimum, were analysed in the data time series 1959-2001. The temporal trends were investigated using linear regression and the non-parametric Whirsch test. The future characteristics of the Baltic Sea are discussed taking into account the development of driving forces.  相似文献   

A Late Paleoproterozoic (1.80 Ga) subduction-related mafic igneous suite from Lomza, NE Poland     

Ewa Krzemi&#;ska  Ian Williams  Janina Wiszniewska 《地学学报》2005,17(5):442-449

The Lomza orthoamphibolites in the crystalline basement of NE Poland, dated at 1802 ± 9 Ma by SHRIMP zircon U–Pb, are characterized by high incompatible and REE element contents. These features, the low Nb, and the position of the rock compositions on La–Y–Nb, Zr–Nb/Zr and Zr–Nb–Y tectonomagmatic discrimination diagrams, suggest that the metavolcanics formed in a subduction setting, possibly within a continental margin island arc. The likely extension of the belt of Paleoproterozoic mafic magmatism from Latvia and Lithuania into NE Poland provides convincing evidence for the existence of an active plate margin in that region at that time.  相似文献   

Correlating specific conductivity with total hardness in gypsum karst waters   总被引：1，自引：0，他引：1  

Wiesława Ewa Krawczyk  Derek C. Ford 《地球表面变化过程与地形》2007,32(4):612-620

Modern digital conductivity meters are readily portable, robust, cheap, and give precisely reproducible values of specific electrical conductivity (SpC, in µS cm^?1). Here we investigate the accuracy of their estimates of the amounts of gypsum dissolved in waters collected in gypsum karst terrains, expressed as total hardness (TH) in mg L^?1 of CaSO₄·2H₂O (GYP). Total dissolved solid concentrations (TDS) are also considered. Curves obtained with the program PHREEQC, for the dissolution of pure gypsum in water at 25 C, are compared with 574 comprehensive water chemical analyses selected from gypsum karst studies in Europe and the Americas. Principal common and foreign ions encountered are the BNC group (bicarbonates, nitrates, chlorides). It is found that GYP = 1·12^·SpC + 62 where BNC < 33% (Cl^? < 5%), with one standard error <5% for waters with SpC > 2400 µS cm^?1; GYP = 0·74^·SpC + 777 where BNC < 33% (5% ≤ Cl^? < 15%), with one standard error <10% for waters with SpC > 3100 µS cm^?1; GYP = 0·97^·SpC ? 209 where BNC < 33% and Cl^? ≥ 15%, with one standard error <10% for samples with SpC > 4300 µS cm^?1. There are similar results for the more complex waters found in gypsum karsts where much carbonate rock or salt is also present, to the limit of BNC < 50% for what may reasonably be defined as ‘gypsum waters’. Values of R² for linear correlations of different subsets of the water samples range from 0·69 to 0·96, the majority being >0·8. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Biostratigraphy of the lower red shale interval in the Rhenodanubian Flysch Zone of Austria   总被引：2，自引：1，他引：2  

Michael Wagreich  Polina Pavlishina  Ewa Malata 《Cretaceous Research》2006,27(6):743-753

In the Rhenodanubian Flysch Zone of Austria, between the Aptian–Albian “Gault Flysch” and the Cenomanian–Turonian Reiselsberg Formation, an interval with predominant red shales (“Untere Bunte Schiefer”) occurs. In the Oberaschau section near Attersee (Upper Austria) a ca. 18-m-thick interval of alternating red and grey shales and marlstones with minor sandstones is present. Thin sandstone intercalations are interpreted as distal turbidites. Dinoflagellate cyst assemblages indicate the Litosphaeridium siphoniphorum Zone. The concurrent presence of Litosphaeridium siphoniphorum and Ovoidinium verrucosum in all samples allows a correlation to the lower part of this zone, thus defining a Late Albian–Early Cenomanian age. Based on foraminifera, the red beds can be assigned to the topmost Rotalipora appenninica Zone and the Rotalipora globotruncanoides Zone due to the presence of small morphotypes of the index taxa. Nannofossils indicate standard zones CC9/UC0 throughout the red interval, defined by the first occurrence of Eiffellithus turriseiffelii, and UC1 above the red shales. Based on these multistratigraphic data, a latest Albian–Early Cenomanian age can be inferred.  相似文献   

On the coupling of lunisolar resonances for Earth satellite orbits     

SŁawomir Breiter 《Celestial Mechanics and Dynamical Astronomy》2001,80(1):1-20

The resonance C1 occurs when the longitude of the perigee measured from the equinox becomes a slow angle in the doubly averaged equations of motion. This resonance is one of the critical inclination family with I 46°. For prograde Earth satellite orbits, up to five critical points can be identified. Only simple pitchfork bifurcations occur for the single resonance C1. A two degrees of freedom system is studied to check how a coupling of two lunisolar resonances affects the results furnished by the analysis of an isolated resonance case. In the system with two critical angles (g+h and h,+2 , seven types of critical points have been identified. The critical points arise and change their stability through 11 bifurcations. If the initial conditions are selected close to the critical points, the system becomes chaotic as shown in Poincaré maps.  相似文献   

Universal profile of dark matter haloes and the spherical infall model     

Ewa L. okas 《Monthly notices of the Royal Astronomical Society》2000,311(2):423-432

I propose a modification of the spherical infall model for the evolution of density fluctuations with initially Gaussian probability distribution and scale-free power spectra in the Einsteinde Sitter universe as developed by Hoffman & Shaham. I introduce a generalized form of the initial density distribution around an overdense region and cut it off at half the interpeak separation, accounting in this way for the presence of the neighbouring fluctuations. Contrary to the original predictions of Hoffman & Shaham, the resulting density profiles within virial radii no longer have a power-law shape, but their steepness increases with distance. The profiles of haloes of galactic mass are well fitted by the universal profile formula of changing slope obtained as a result of N -body simulations by Navarro, Frenk & White. The trend of steeper profiles for smaller masses and higher spectral indices is also reproduced. The agreement between the model and simulations is better for smaller masses and lower spectral indices, which suggests that galaxies form mainly by accretion, while formation of clusters involves merging.  相似文献   

Water chemistry and hydrometeorology in a glacierized catchment in the Polar Urals,Russia     

Łukasz Stachnik  Piotr Wałach  Łukasz Uzarowicz  Jacob C. Yde  Zornitza Tosheva  Dominika Wrońska-Wałach 《山地科学学报》2014,11(5):1097-1111

This study aims to determine the relationships between local meteorological conditions,proglacial river discharge and biogeochemical processes operating in a periglacial basin located in the Polar Ural mountain range, Russia. Fieldwork was conducted in the catchment of Obruchev Glacier(13 km2) during the summer peak flow period in 2008. River discharge was dominated by snowmelt and changed from 3300 l s-1 to less than 1000 l s-1. The mean daily air temperatures of stations situated in the mountain tundra and near Obruchev Glacier from July 11 th to August 1st 2008 were 14.4°C and 10.3°C, respectively. The glacial river had low total dissolved solids varying from 4.5 to 9 mg l-1 and coefficients of correlation between Na+ and Cl-, K+ and Cl-, as well as NH4+ and Cl- were 0.94, 0.90 and 0.84, respectively. Rainfall events affected the snowmelt initiation and provided an essential part of the discharge during the intense snowmelt period, which occurred from July 11 th to July 18 th 2008. Data showed that Na+ and K+ in the surface water derived from snowmelt rather than chemical weathering of silicates. Also, it was obtained that NO3- derived from the melting snowpack, whereas ammonification occurring under the snowpacks was the primary source for NH4+.  相似文献   

Random cascade driven rainfall disaggregation for urban hydrology: An evaluation of six models and a new generator     

Paweł Licznar  Janusz Łomotowski  David E. Rupp 《Atmospheric Research》2011,99(3-4):563-578

Six variations of multiplicative random cascade models for generating fine-resolution (i.e., 5-minute interval) rainfall time series were evaluated for rainfall in Wroclaw, Poland. Of these variations, one included a new beta-normal generator for a microcanonical cascade. This newly proposed model successfully reproduces the statistical behavior of local 5-minute rainfalls, in terms of intermittency as well as variability. In contrast, both the canonical cascade models with either constant or time-scaled parameters and a microcanonical cascade model with a beta generator substantially underestimate 5-minute maximum rainfall intensities. The canonical models also fail to properly reproduce the intermittency of the rainfall process across a range of timescales. New observations are also made concerning the histograms of the breakdown coefficients (BDC). The tendency of the BDC histograms to have values exactly equal to 0.5 is identified and explained by the quality of pluviograph records. Moreover, the hierarchical evolution of BDC histograms from beta-like for long time steps to beta-normal histograms for short time steps is observed for the first time. The potential advantage is shown of synthetic high resolution rainfall time series generated by the revised microcanonical model for use in hydrology, especially hydrodynamic modelling of urban drainage networks.  相似文献