The occurrence of some metals in mesozooplankton taken from the southern Baltic     

Piotr Szefer  Bogdan Skwarzec  Jolanta Koszteyn 《Marine Chemistry》1985,17(3):237-253

The determination of Fe, Mn, Ni, Pb, Cu, Co, Zn, Cd, K and Na was carried out in the mesozooplankton caught in the southern Baltic in July 1980. The species structure of mesozooplankton was characterized on the basis of mean numbers of particular components and their percentage. The chemical analyses of the samples of mesozooplankton show a wide range of values, although they were within the ranges published for zooplankton from other aquatic regions of the world. Both concentration factors and selectivity factors for Zn, Cd, Pb and Cu in the organisms analysed were calculated. The significant cross-correlation coefficients calculated for all possible pairs of metals showed the following associations: CuPbNiMnFe, MnZn and NaZn.  相似文献   

Removal of lead minerals from copper industrial flotation concentrates by xanthate flotation in the presence of dextrin     

Jan Drzymala  Janusz Kapusniak  Piotr Tomasik 《International Journal of Mineral Processing》2003,70(1-4):147-155

Potato starch and dextrins resulting from thermolysis of potato starch in the absence of reagents and presence of -amino acids are promising depressants for separation of lead and copper minerals present in the Polish industrial copper concentrates. The polysaccharides were used for differential xanthate flotation of the final industrial concentrates produced by flotation with sulfhydryl collectors in the absence of depressants. The polysaccharides depressed galena and provided froth concentrate rich in chalcocite and other copper minerals as well as cell product containing lead minerals. The best results of separation were obtained in the presence of plain dextrin prepared by a thermal degradation of potato starch. The industrial concentrate containing 18.5% Cu and 5.5% Pb was divided into a froth product containing 38.1% Cu with 77% recovery of copper and a cell product assaying 7.3% Pb with 83% recovery of lead. It was accomplished using 2500 g/t of dextrin, 50g/t of potassium ethyl xanthate, and 50 g/t of frother (α-terpineol). The pH of flotation was 8.0–8.2.  相似文献   

Different modes of the Late Cretaceous–Early Tertiary inversion in the North German and Polish basins     

Stanislaw Mazur  Magdalena Scheck-Wenderoth  Piotr Krzywiec 《International Journal of Earth Sciences》2005,94(5-6):782-798

Several selected seismic lines are used to show and compare the modes of Late-Cretaceous–Early Tertiary inversion within the North German and Polish basins. These seismic data illustrate an important difference in the allocation of major zones of basement (thick-skinned) deformation and maximum uplift within both basins. The most important inversion-related uplift of the Polish Basin was localised in its axial part, the Mid-Polish Trough, whereas the basement in the axial part of the North German Basin remained virtually flat. The latter was uplifted along the SW and to a smaller degree the NE margins of the North German Basin, presently defined by the Elbe Fault System and the Grimmen High, respectively. The different location of the basement inversion and uplift within the North German and Polish basins is interpreted to reflect the position of major zones of crustal weakness represented by the WNW-ESE trending Elbe Fault System and by the NW-SE striking Teisseyre-Tornquist Zone, the latter underlying the Mid-Polish Trough. Therefore, the inversion of the Polish and North German basins demonstrates the significance of an inherited basement structure regardless of its relationship to the position of the basin axis. The inversion of the Mid-Polish Trough was connected with the reactivation of normal basement fault zones responsible for its Permo-Mesozoic subsidence. These faults zones, inverted as reverse faults, facilitated the uplift of the Mid-Polish Trough in the order of 1–3 km. In contrast, inversion of the North German Basin rarely re-used structures active during its subsidence. Basement inversion and uplift, in the range of 3–4 km, was focused at the Elbe Fault System which has remained quiescent in the Triassic and Jurassic but reproduced the direction of an earlier Variscan structural grain. In contrast, N-S oriented Mesozoic grabens and troughs in the central part of the North German Basin avoided significant inversion as they were oriented parallel to the direction of the inferred Late Cretaceous–Early Tertiary compression. The comparison of the North German and Polish basins shows that inversion structures can follow an earlier subsidence pattern only under a favourable orientation of the stress field. A thick Zechstein salt layer in the central parts of the North German Basin and the Mid-Polish Trough caused mechanical decoupling between the sub-salt basement and the supra-salt sedimentary cover. Resultant thin-skinned inversion was manifested by the formation of various structures developed entirely in the supra-salt Mesozoic–Cenozoic succession. The Zechstein salt provided a mechanical buffer accommodating compressional stress and responding to the inversion through salt mobilisation and redistribution. Only in parts of the NGB and MPT characterised by either thin or missing Zechstein evaporites, thick-skinned inversion directly controlled inversion-related deformations of the sedimentary cover. Inversion of the Permo-Mesozoic fill within the Mid-Polish Trough was achieved by a regional elevation above uplifted basement blocks. Conversely, in the North German Basin, horizontal stress must have been transferred into the salt cover across the basin from its SW margin towards the basins centre. This must be the case since compressional deformations are concentrated mostly above the salt and no significant inversion-related basement faults are seismically detected apart from the basin margins. This strain decoupling in the interior of the North German Basin was enhanced by the presence of the Elbe Fault System which allowed strain localization in the basin floor due to its orientation perpendicular to the inferred Late Cretaceous–Early Tertiary far-field compression.  相似文献   

Spatial Prediction of Landslide Hazard Using Fuzzy k-means and Dempster-Shafer Theory   总被引：2，自引：0，他引：2  

Pece V. Gorsevski  Piotr Jankowski  Paul E. Gessler 《Transactions in GIS》2005,9(4):455-474

Landslide databases and input parameters used for modeling landslide hazard often contain imprecisions and uncertainties inherent in the decision‐making process. Dealing with imprecision and uncertainty requires techniques that go beyond classical logic. In this paper, methods of fuzzy k‐means classification were used to assign digital terrain attributes to continuous landform classes whereas the Dempster‐Shafer theory of evidence was used to represent and manage imprecise information and to deal with uncertainties. The paper introduces the integration of the fuzzy k‐means classification method and the Dempster‐Shafer theory of evidence to model landslide hazard in roaded and roadless areas illustrated through a case study in the Clearwater National Forest in central Idaho, USA. Sample probabilistic maps of landslide hazard potential and uncertainties are presented. The probabilistic maps are intended to help decision‐making in effective forest management and planning.  相似文献   

The Role of Sorption in the Transport of Klebsiella oxytoca Through Saturated Silica Sand     

M. J. Hendry  J. R. Lawrence  P. Maloszewski 《Ground water》1997,35(4):574-584

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Great tritium ages explain the occurrence of good-quality groundwater in a phreatic aquifer of an urban area, Lublin, Poland   总被引：1，自引：0，他引：1  

A. Zuber  Z. Michalczyk  P. Maloszewski 《Hydrogeology Journal》2001,9(5):451-460

The phreatic aquifer of the Lublin chalk in the watershed of the Bystrzyca River, eastern Poland, is characterized by waters of good quality. Its hydraulic conductivity is related to a fissure network of low porosity, as much as 0.006 at the outcrops. The good quality of water in this urban setting is surprising because, according to estimates based on Darcy's law, a high seepage velocity would be expected, resulting in rapid transport of pollutants in the aquifer. However, tritium sampling reveals that the mean ages range from about 55 to 92 years in four cases, and about 250 to 350 years in 11 cases. One sampling site is free of tritium, which indicates an even greater age. Such great ages can be explained only by a retardation of solute transport due to matrix diffusion, that is, an exchange between mobile water in the fissures of low porosity and stagnant water in the matrix of high porosity. The delay factor is given as the ratio of total porosity to fissure porosity. In consequence, all types of dissolved constituents and, to some degree, fine suspended matter are delayed in their transport to springs and wells. In addition, non-conservative constituents have longer times to sorb, react, and decay than in the case of transport without a dominant influence of matrix diffusion. Though pollutants are greatly delayed, their accumulation in the matrix and slow diffusion into the fissures contribute to their persistence in groundwater. Regional values of hydraulic conductivity, estimated from tritium ages and known matrix porosity, agree reasonably well with the values known from pumping tests, which supports the interpretation of a dominant influence of matrix diffusion on solute transport. Electronic Publication  相似文献   

Les auditeurs polonais des cours de minéralogie de René Just Haüy au Muséum national d'Histoire naturelle,Paris     

Radosław Tarkowski  Piotr Daszkiewicz 《Comptes Rendus Geoscience》2006,338(11):809-814

The paper analyses a list of thirty-four Poles, listeners to the mineralogy lectures given by R.-J. Haüy at MNHN in Paris. These students played an important role in the history of Polish Earth Sciences (S. Staszic and F. Drzewiński), but also in other scientific fields (J. Markowski, I. Ab?amowicz, F. Drzewiński, M.A. Paw?owicz, J.K. Skrodzki, E.K. Nowicki), and even in political and cultural life of Poland (A. Downarowicz, J. Weyssenhoff, S. Plater, J. Bieliński, F. Potocki). This paper presents later relations between R.-J. Haüy and his Polish students. A possibility of the Poles' attendance to mineralogy lectures given at other Parisian scientific institutions, like the ‘École des mines’ and the ‘College de France’, is also discussed. To cite this article: R. Tarkowski, P. Daszkiewicz, C. R. Geoscience 338 (2006).  相似文献   

Heavy metals in sediments as evidence for recent pollution and quasi-estuarine processes: an example from Lake Druzno,Poland   总被引：1，自引：0，他引：1  

Wojciech Tylmann  Roman Gołębiewski  Piotr Paweł Woźniak  Karolina Czarnecka 《Environmental Geology》2007,53(1):35-46

This article presents the results of a geochemical investigation of sediments from Lake Druzno (northern Poland), a reservoir fed by freshwater from the catchment, with periodic input of brackish water from Vistula Lagoon. This study analyzed the spatial variation in heavy metal content in surface sediments as well as the temporal changes in metal content in two sediment cores dated using the ²¹⁰Pb method. In the surface sediments, the highest metal concentrations were recorded in the northern part of the lake, with lower concentrations in the central and southern parts. Absolute values of metal concentrations in the cores were low, but normalization with respect to Al showed an increase during the second half of the 20th century. Mean enrichment factors (EF) in sediments from the second half of the 20th century ranged from insignificant (1–1.2) for Fe to (1.55–3.3) for Cu, Cd, Pb and Zn. The sediments deposited before 1950 had lower EF values (>1.5) and had low variability. Results from both the surface sediments and the cores indicate that the main source of lake pollution is brackish water intrusion from the Vistula Lagoon via the contaminated River Elbląg.  相似文献   

Fluoride ions in groundwater of the Turkana County,Kenya, East Africa     

Rusiniak  Piotr  Sekuła  Klaudia  Sracek  Ondra  Stopa  Piotr 《中国地球化学学报》2021,40(6):945-960

Acta Geochimica - Groundwater samples were evaluated throughout Turkana County (Kenya, East Africa) while looking for drinking water sources. Some samples showed high concentrations of fluoride...  相似文献   

Impulse approximation improved     

Piotr A. Dybczyński 《Celestial Mechanics and Dynamical Astronomy》1994,58(2):139-150

Improved formulas of impulse approximation method for stellar perturbations are derived. The method proposed involves a deflection of the stellar path. It is also applicable to an arbitrary time interval. A comparison of the classical vs improved method is presented both in qualitative discussion and numerical results for Oort cloud cometary orbits.  相似文献