Investigation of superstructures in mullite by high resolution electron microscopy and electron diffraction     

J. Ylä-Jääski  H.-U. Nissen 《Physics and Chemistry of Minerals》1983,10(2):47-54

Superstructures in synthetic mullite, Al_4+2x Si_2?2x O_10?x , prepared using the zone melting technique, are studied by high resolution electron microscopy (HREM), electron diffraction, and in situ energy dispersive X-ray spectroscopy. For x=0.40 composition HREM images indicate only short-range order. Near x=0.5 composition mullite has an antiphase domain structure with antiphase boundaries (APB's) oriented parallel to (100). For higher Al-content the APB's run in non-rational orientations which are slightly inclined against the {601}-planes. We propose models for the superstructures in which oxygen vacancies are arranged in channels parallel to the crystal b-axis. The models are supported by a one-to-one match between observed and computer-simulated images. An Al-rich limit of x=2/3 for mullite is deduced on the basis of stereochemical considerations. Different ordering schemes for the tetrahedral cations are believed to result in the orientation change of the APB's near x=0.5 composition.  相似文献   

Albian and Cenomanian planktic Foraminiferida from the Trawne Beds (Pieniny Klippen Belt,Polish Carpathians)     

M.A. Gasiński 《Cretaceous Research》1983,4(3):221-249

Eighteen Albian and Cenomanian planktic Foraminiferida from the Pieniny Klippen Belt of Poland are discussed. A local biostratigraphic zonation (six zones) is proposed and certain problems of palaeoecology are reviewed. The lithostratigraphical element is the so-called Trawne Beds, a Cretaceous flysch in the Pieniny Klippen Belt.  相似文献   

A RATAN-600 Zenith-Field sky survey. Catalog of radio sources     

N. N. Bursov  Yu. N. Pariĭskiĭ  E. K. Maĭorova  M. G. Mingaliev  A. B. Berlin  N. A. Nizhel’skiĭ  I. A. Glushkova  T. A. Semenova 《Astronomy Reports》2007,51(3):197-214

A catalog of radio sources detected in a deep RATAN-600 survey is presented. The catalog was obtained in the region 0^h ≤ RA_2000.0 ≤ 24^h, Dec_2000.0 = 41°30′42″ ± 2′, at the declination of the bright radio source 3C 84. There were nine sessions of multi-wavelength observations at wavelengths λ = 1–55 cm, and more than 300 daily scans were accumulated at each wavelength. This is the first stage in the reduction of an extensive database accumulated by the Cosmological Gene Project. The RATAN-600 Zenith Field (RZF) catalog was obtained at the central wavelength of 7.6 cm, and contains 437 radio sources, virtually all of which have been identified with NVSS objects. Most of the flux densities for the catalog sources are above the 5σ level. Noise from faint (mainly new) background sources at a level of about 0.8 mJy has been detected. The minimum flux density of the catalog, 2.5 mJy, is comparable to the flux-density linit of the NVSS catalog. The catalog is more than 80% complete for sources with flux densities >3 mJy.  相似文献   

Environmental Hydraulics     

Paweł M. Rowiński 《Acta Geophysica》2007,55(1):1-2

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Use of variograms for field magnetometry analysis in Upper Silesia Industrial Region     

J. Zawadzki  P. Fabijańczyk 《Studia Geophysica et Geodaetica》2007,51(4):535-550

Measurements of topsoil magnetic susceptibility are often used for quick assessment of soil contamination of anthropogenic origin, with heavy metals or other pollutants. However, because of complicated correlations between low-field magnetic susceptibility (shortened to magnetic susceptibility) of topsoil and soil pollution, the outcome of a field magnetometry survey can not be related directly to soil pollution. For each case study, the results should be interpreted on their own taking into account not only the type of pollution but also pedogenic, biogenic and environmental factors. In practice, it is very difficult to measure and consider all these factors. Here we illustrate the merit of geostatistical methods, which are focused on the spatial variability of a phenomenon, in the interpretation of soil magnetometry results. This article presents the analysis of spatial variability of top soil layers magnetic susceptibility-within the Upper Silesia Industrial Region (USIR)-using semivariance analysis. It also explains how to adjust the sampling density of field magnetometry measurements to spatial variability of the soil pollution as well as to the spatial scale of the investigated area. For this purpose, the values of magnetic susceptibility have been measured by using various sampling densities at areas of different size located within USIR. This enabled to determine the main scales of magnetic susceptibility spatial variability of soils within USIR using semivariance. A few distinct scales of variability were found from the site scale to a more regional scale. Variability ranges of 30 km, 12 km, and 5 km refer to the large regional scale, whereas smaller ranges of few hundreds down to a few tens of meters, can be attributed to the local (site) scale. In addition, the precision of the measuring campaigns, performed within USIR with different sampling densities, was compared through the analysis of the spatial variability of the soil magnetic susceptibility signal by using ordinary kriging. jarek97@yahoo.com, piotr.fabijanczyk@is.pw.edu.pl  相似文献   

Wassereintrittsgeschwindigkeit zum Brunnenfilter in bezug auf die Berechnung der Filterdurchmesser     

Alfred Kepiński 《Aquatic Sciences - Research Across Boundaries》1962,24(2):272-290

Ohne Zusammenfassung  相似文献   

Origin of magnetic minerals and natural remanent magnetization of basaltic rocks from Lower Silesia,Poland     

J. Kruczyk  M. Kądziałko-Hofmokl  M. Jeleńska 《Pure and Applied Geophysics》1973,110(1):2031-2040

Summary Two groups of basaltic rocks with normal and reversed NRM were examined. It was found that in both groups the primary NRM, synchronous with the period of rock formation, is preserved. Relations of the primary NRM to the origin and the degree of oxidation of magnetic minerals were considered in detail.  相似文献   

Book reviews     

A. M. O'Connor  Fouad Ibrahim  W. F. Schmidt-Eisenlohr  Olof Nordström  Gunnar Alexandersson  Lutz Holzner  L. A. Kosiński 《GeoJournal》1978,2(5):492-494

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Rare and vulnerable species in the mollusc communities in the mining subsidence reservoirs of an industrial area (The Katowicka Upland, Upper Silesia, Southern Poland)   总被引：1，自引：0，他引：1  

Iga Lewin  Adam Smoli&#x;ski 《Limnologica》2006,36(3):181-191

Pollution of the water environment by mining waters is a problem not only in Poland, but worldwide. This study investigated the mollusc communities in seven mining subsidence reservoirs affected by coal mine output (the Katowicka Upland, Upper Silesia, Southern Poland). The objective of the survey was to determine the relationship between the molluscs and their environments and to evaluate the ecological-conservation value of freshwater habitats which support rare and vulnerable molluscs. From 1993 to 2005, 23 mollusc species were recorded. Our result confirmed an invasion by Potamopyrgus antipodarum (Gray, 1843), whose density varied from 2 to 2422 individuals/m² in the waters of the Katowicka Upland. A few rare and vulnerable species were found, e.g. Acroloxus lacustris (Linnaeus, 1758), Hippeutis complanatus (Linnaeus, 1758), Ferrissia wautieri (Mirolli, 1960), Anodonta anatina (Linnaeus, 1758), Musculium lacustre (O.F. Müller, 1774) or Pisidium casertanum (Poli, 1791). Principal component analysis showed a positive correlation between mollusc density and pH, the concentration of chlorides, the total hardness, alkalinity and total dissolved solids, and a negative correlation between the number of species and phosphates. Because of the distinctive environmental features of the mining subsidence reservoirs in Czułów, the research area has provided a refuge for wildlife.  相似文献   

Some observations of bipolar flashes during summer thunderstorms near Warsaw     

Piotr Barański  Paweł Bodzak 《Acta Geophysica》2006,54(1):71-89

Lightning discharges monitored by the SAFIR network system in Poland have been additionally identified over the 100×100 km area near Warsaw by single-point independent recordings of electric field and Maxwell current rapid changes. The data collected in summer thunderstorm days of 2002 showed some untypical properties of the lightning discharges which are rarely observed. Especially remarkable was a number of ground multi-stroke flashes with the return strokes (RS) which transported to the earth charges of opposite signs. Bipolar flashes (BF) of this kind were mostly involved in the events in which the nearby intracloud (ic) and cloud-to-ground (c-g) discharges were very closely associated in time. Events of such a close collocation of two different types of lightning discharges, previously called the complex lightning discharge events (CLDE), were quite often observed during summer thunderstorms in Poland. The events of this kind, i.e. 8 flashes, identified by the SAFIR detection system as BF’s present the multiple stroke flashes of the mean horizontal separation distance between striking points of particular RS equal to (2.8 ± 2.1) km and of the mean time interval between strokes of (46.8 ± 74.4) ms. The time separation between the observed BF and the adjacent ic flashes was from 0.1 to 335 ms, and horizontal separation distance between them ranged from 1.8 to 14.5 km. The multiplicity of the recorded BF’s ranged from 2 to 4 strokes. Four of these BF’s followed the ic discharge, but the other three preceded the ic and one was alone with no close ic.  相似文献