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11.
J. Keder M. Střižík P. Berger A. Černý P. Engst I. Němcová 《Meteorology and Atmospheric Physics》2004,85(1-3):155-164
Summary Air pollution problem in the Czech Republic is very complex due to large number of factors as turbulent dispersion and chemical reactions concurring in the status of the PBL. For this 3D distribution of pollutants is a key information that cannot be given by conventional monitoring stations. Combined use of DIAL lidar and sodar can give access to such information. Case studies of air pollutants transport are presented using 3D concentration fields of NO2 and ozone measured by lidar and meteorological conditions monitored by Doppler Sodar. 相似文献
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ELVIRA KOVAČ-ANDRIĆ ALAA SHETA HOSSAM FARIS MARTINA ŠRAJER GAJDOŠIK 《Journal of Earth System Science》2016,125(5):997-1006
Ozone is one of the most significant secondary pollutants with numerous negative effects on human health and environment including plants and vegetation. Therefore, more effort is made recently by governments and associations to predict ozone concentrations which could help in establishing better plans and regulation for environment protection. In this study, we use two Artificial Neural Network based approaches (MPL and RBF) to develop, for the first time, accurate ozone prediction models, one for urban and another one for rural area in the eastern part of Croatia. The evaluation of actual against the predicted ozone concentrations revealed that MLP and RBF models are very competitive for the training and testing data in the case of Kopa?ki Rit area whereas in the case of Osijek city, MLP shows better evaluation results with 9% improvement in the correlation coefficient. Furthermore, subsequent feature selection process has improved the prediction power of RBF network. 相似文献
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Summary Intimate intergrowths of ferrotantalite and ferrotapiolite occur in a pegmatite in Spittal a.d. Drau, Carinthia. They are associated with muscovite, albite, smoky quartz, cassiterite, and microscopic uranmicrolite, zircon and uraninite. An assemblage of secondary uranium minerals is also present, generated by extensive alteration and leaching of the uranmicrolite and zircon. Textures of the ferrotantalite-ferrotapiolite intergrowths suggest considerable recrystallization that obliterated most of their primary features; neither coprecipitation nor exsolution can be recognized with certainty. Despite intersecting tielines indicating disequilibrium, the ferrotantalite and ferrotapiolite compositions show very restricted ranges (Mn/(Mn + Fe) 0.08–0.11, Ta/(Ta + Nb) 0.53–0.57 for ferrotantalite, and 0.01–0.04, 0.84–0.89 for ferrotapiolite, respectively), particularly in comparison with compositions from other localities featuring primary textures. A degree of compositional equilibration could have been attained during recrystallization. This process may also explain the high level of structural order characterizing both minerals; they are considerably disordered in other localities. Extensive deformation typical of pegmatites in the southern Ostalpen in general, and specifically of the Spittal pegmatite, is probably responsible for the recrystallization phenomena in the Ta, Nb, Sn-bearing mineral assemblage.
Eine Ferrotantalit-Ferrotapiolit Verwachsung von Spittal a.d. Drau, Kärnten, österreich
Zusammenfassung In einem Pegmatit von Spittal a.d. Drau, Kärnten, treten enge Verwachsungen von Ferrotantalit und Ferrotapiolit auf. Diese werden von Muskovit, Albit, Rauchquarz, Zinnstein sowie-in mikroskopischem Masstab-von Uranmikrolith und Zirkon begleitet. Die Textur der Verwachsungen lässt Rekristallisation erheblichen Ausmasses erkennen, die die primären Merkmale weitgehend auslöscht. Weder eine gemeinsame Auskristallisation der beiden Mineralphasen noch eine Bildung durch Entmischung kann mit Sicherheit erkannt werden. Trotz einander kreuzender Verbindungslinien, die einen Hinweis auf Ungleichgewicht darstellen, zeigen die Zusammensetzungen des Ferrotantalits und des Ferrotapiolits lediglich geringe Schwankungsbreiten: Mn/(Mn + Fe) 0,08–0,11, Ta/(Ta + Nb) 0,53–0,57 für den Ferrotantalit beziehungsweise 0,01–0,04 und 0,84–0,89 für den Ferrotapiolit. Dies gilt insbesondere für den Vergleich mit Zusammensetzungen solcher Mineralphasen mit jenen von Fundarten, die primäre Verwachsungstrukturen aufweisen. Bis zu einem gewissen Ausmass ist diese homogene Zusammensetzung möglicherweise auf die Rekristallisation zurück zuführen. Diese Rekristallisation könnte auch den hohen strukturellen Ordnungsgrad der beiden Mineralphasen erklären. An anderen Fundorten zeigen diese Minerale strukturell merklich geringeren Ordnungsgrad. Intensive metamorphe überprägung, wie sie für die Pegmatite in den südlichen Ostalpen und insbesondere für jenen von Spittal typisch sind, kann wahrscheinlich als Ursache der Rekristallisationsphänomene der Ta-Nb-Sn Mineralparagenese angenommen werden.相似文献
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Jana Konopásková Vlastislav Červený Reviewer I. Pšenčik 《Studia Geophysica et Geodaetica》1984,28(2):113-128
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Studia Geophysica et Geodaetica - 相似文献
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M. Čadež 《Pure and Applied Geophysics》1960,45(1):227-237
Summary One can find that over the continent the cold fronts becomes stationary after the sunrise. In the present paper this phenomen is explaned by heating of cold air what causes the increase of the slope of the boundary surface. Because of surface heating of the cold air the horizontal pressure gradient in direction toward the front increases with time, and so increases the transport of the cold air in this direction too. The increasing of the slope of boundary surface that is in connection with the mentioned increased trasport of cold air, causes the convergence of air mass and the ascent of it at the same front (Fig. 2).As the consequence of the heating from the surface and the liberation of latent heat of vaporisation, the volume of cold air increases. In connection with this the divergence of mass occures in the high levels and later one can find at the surface the corresponding fall of pressure. This effects can cause in suitable cases the development of cyclon, similarily as shown on Fig. 4. When the cold air comes from the cold continent over a relatively warm sea surface, the strong heating of cold air occurs and as consequence of this, the cyclogenesis. 相似文献
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Marjan Čadež 《Pure and Applied Geophysics》1972,93(1):187-190
Summary The forces due to compressibility of a fluid and their action on moving bodies have been studied. Also a possible practical application of these forces in a propulsion mechanism for vehicles has been discussed.
Zusammenfassung Im vorliegenden Beitrag wird die Wirkung der Kräfte auf bewegende Körper, die durch Kompressibilität des Mediums bedingt sind, untersucht. Es wird über die Möglichkeit der Konstruktion eines Mechanismus auf diesem Prinzip diskutiert.相似文献