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281.
Ivana Nemešová Eva Smítková Reviewer O. Zikmunda 《Studia Geophysica et Geodaetica》1982,26(2):176-186
Summary A model of a building cumulus structure is described. The one-stage model published in[1] was used to describe ascent of two cloudy parcels that a cloud is supposed to be formed of. The other ascent is assumed to take place after the first cloud element sinks back as a result of evaporative cooling. The numerical results and their evaluation are given for various rates of mixing at the cloud top level of the first cloud volume. 相似文献
282.
Vít Kárník Zdeňka Schenková Vladimír Schenk Reviewer K. Pěč 《Studia Geophysica et Geodaetica》1982,26(1):42-58
Summary The time development of three large sequences, Friuli 1976, Thessaloniki 1978 and Monte Negro-Albania 1979, was investigated by analysing the characteristics of the time distribution of magnitudes of the events, M(t), of average magnitudes,
(t), and of the number of events, n(t), as well as the strain release curves and the magnitude-frequency relations, N(M). The existence of time gaps and of an anomalous decay of the numbers of shocks before major events, as well as the oscillation of
( const b–1) may be considered as precursory phenomena. The clustering of events has been tested by the Poisson and negative binomial laws.Communication presented at the XVIIth General Assembly of the European Seismological Commission in Budapest, 21–29 August, 1980 under the title Properties of Seismic Regime and Recent Earthquake Sequences in Europe. 相似文献
283.
Results of a semi-implicit two-step method for the simulation of markedly nonlinear flow in coastal seas 总被引:1,自引:0,他引:1
Results of a numerical method for the simulation of nonlinear flow in coastal seas are presented. The method is based on a neutral semi-implicit scheme which is modified into a stability-enhancing two-step algorithm. By means of this method the simulation of highly nonlinear flow patterns is possible in a stable and economic way. Three examples of models of different North Sea coastal regions are discussed under certain aspects to demonstrate the reliability of the method. 相似文献
284.
Beatriz Levi Luis Aguirre Jan Olov Nyström 《Contributions to Mineralogy and Petrology》1982,80(1):49-58
Partial spilitization of a 9 km thick pile of flood basalts with highly vesicular flow tops gave rise to patterns of secondary mineralogy at different scales: (a) a local pattern of mineralogical variation from the almost unaltered bottom towards the altered top of each flow, and (b) an overall pattern, comparing flow tops throughout the pile, with changes in mineralogical composition within a sequence of metamorphic zones and facies. The local patterns mimic the trend of the overall pattern, but are of opposite direction and telescoped. Thus, a gradual ordering and Andepletion of the secondary albite and increases in the Fe*/Al ratio of epidote and pumpellyite upwards within individual flows are comparable in range to corresponding overall changes downwards throughout several kilometres. The mineralogical changes within the flows diminish in range towards the more altered deeper part of the pile.The local and overall patterns cannot be interpreted in terms of grade. They represent trends from metastable towards stable equilibrium, this latter only approached in the flow tops of the lower part of the pile. The patterns of secondary mineralogy were formed by an interplay of metamorphic gradients at different scales at any given time, and as burial proceeded. The overall pattern was caused by depth-controlled gradients: increasing P
fluid, temperature and temperature-induced increase of reaction rates, and decreasing fO2 (downwards in the pile). The local patterns resulted from permeability-controlled gradients: increasing reaction rates, fO2 and contrast in chemical activity between different domains, and decreasing P
fluid (upwards in each flow). The mineralogical observations reported in this paper fall into line if the overall temperature-induced increase of reaction rates and the local permeability-controlled rate factors played the leading role during burial metamorphism of the pile. 相似文献
285.
This work is immediate continuation of Part I, using an identical method and evaluation for kinetic studies. The systems chalcocite-ethylene diamine tetra-acetic acid and chalcocite-ethylene diamine were studied. It was necessary to refine the geometrical model method for chalcocite in order to establish dissolution kinetics of polydispersions. This work confirms that chalcocite leaching proceeds through covellite even in the medium of complex-forming agents and kinetic equations for both leaching stages were evaluated with an attempt at physical interpretation. 相似文献
286.
Jan Olov Nyström 《International Journal of Earth Sciences》1982,71(1):141-157
Granitoids and associated volcanics, postorogenic in relation to the Svecokarelian orogeny, constitute a belt in central Sweden. Evidence presented in this paper suggest that the belt originated in an Andinotype orogenic environment. The inferred development of the belt was characterized by fracture-controlled high-level emplacement of batholiths in an ensialic setting. Voluminous venting of ignimbrites and formation of grabens through cauldron subsidence accompanied the recurrent intrusive activity. Block movements and episodes of burial metamorphism appear to have been prominent features throughout the history of the post-Svecokarelian belt.
Zusammenfassung Granitoide Plutonite und verwandte Vulkanite, post-orogen im Verhältnis zur Svekokarelischen Orogenese, bilden einen Gürtel in Mittelschweden. Es wird gezeigt, daß der Gürtel in einer andinotypen Orogenese gebildet wurde. Die vorgeschlagene Entwicklung des Gürtels ist geprägt durch spaltentektonisch kontrollierte Platznahme von Batholithen in einem seichten Niveau der Kruste in ensialischem Mileau. Umfangreiche Eruptionen von Ignimbriten sowie die Bildung von Grabenbrüchen durch Kalderen-Einstürzungen begleiten die erneute intrusive Tätigkeit. Blockbewegungen und episodische Versenkungsmetamorphosen sind charakteristisch während der gesamten Entwicklungsgeschichte des post-svekokarelischen Gürtels.
Résumé Des granitoïdes et des volcanites associées, postorogéniques par rapport à l'orogénese svécokarélienne, forment une ceinture en Suède centrale. La présente étude suggère que la mise en place de ces roches s'est effectuée dans un environment orogénique Andinotype. L'évolution de la ceinture c'est caractérisée par la mise en place; contrée par des fractures, de batholites peu profonds, en milieu ensialique. Des volumineuses éruptions d'ignimbrites et la formation de grabens par «cauldron subsidence» ont accompagné la mise en place des batholites. Des mouvements verticaux de blocs, ainsi que des épisodes de métamorphisme d'enfouissement («burial metamorphism») semblent être des faits dominants du développement historique de la ceinture post-svécokarélienne.
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