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The patterns of variation of TiO2 conent during magmatic evolution are different in the so called “orogenic” and “anorogenie” basic associations; these last terms, which are the cause of much misunderstanding, can be replaced by the terms “isotitaniferous” and “anisotitaniferous”.  相似文献   

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The emplacement of Pyrenean lherzolites is a fascinating problem to tackle because of the unusual location of the lherzolites within sediments and the numerous constraints which are currently available on the Pyrenean belt (plates kinematics, petrology, structural geology, geochemistry, geophysics). Our model [1] represents an attempt to integrate the emplacement of lherzolites within the geodynamic evolution of the Pyrenees. However, on the basis of imprecise statements and observations, and neglecting or quoting incorrectly several previous works. Fischer [2] considers that we failed to address a number of problems relevant to the evolution of the North Pyrenean Fault Zone. Most of his comments find an answer in a careful reading of our article; nevertheless the following points must be clearly emphasized.  相似文献   

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The “wave turbopause” is defined as the mesospheric altitude level where the temperature fluctuation field indicates a substantial increase in wave amplitudes in the vertical direction.The turbopause altitude is analyzed on the basis of four years of SABER data (2002–2005, Version 1.06). Substantial seasonal and latitudinal variations are found, with some interannual variability also present. Seasonal changes are annual at high latitudes, semi-annual at low latitudes, and a mixture of both at middle latitudes. Southern hemisphere data are similar as in the North if shifted by half a year. Latitudinal variations show a minimum in the tropics and two relative maxima at middle latitudes.The “wave turbopause” is found near to zero-wind lines or low-wind zones (zonal wind). It is compared to rocket and other measurements, and interesting similarities are obtained. The wave turbopause can also be found in the HAMMONIA GCM. A preliminary analysis shows results similar to those of the SABER measurements.  相似文献   

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Organohalogen compounds are gaining in importance in the control of surface and drinking water due to their unwholesome properties. An accumulation of the organohalogen compounds, occurring mostly at low concentrations, is possible in different ways. The author discusses the possibility and problems of the extractability from waters with the aid of organic solvents. The group parameter EOX that can be determined does not allow any statement concerning components of individual substances, but gives some clues to the state of surface and drinking waters which are mostly anthropogenically polluted. Results of practical examples as well as theoretical considerations indicate the importance of the different distribution coefficients in the solvent/water extraction system. The degree of extraction can be considerably increased by the application of suitable mixtures of solvents. In waters with a known composition, the probably detectable EOX-quantity can be calculated by means of theoretical degrees of extraction.  相似文献   

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Vorgestellt wird ein einfaches Verfahren zur schnellen und gleichzeitig differenzierten Ansprache des Vcrkrautungszustandes von Fließgewässern für Zwecke der wasserwirtschaftlichen Praxis sowie zur ökologischen Beurteilung des Gewässers. Das Verfahren beruht auf der getrennten Bestimmung von Verkrautungsform und Verkrautungsgrad mit Hilfe eines Schlüssels, wobei die Verkrautungsform eine Synthese aus ökologischen und hydraulischen Einheiten darstellt. Die häufigsten Verkrautungsformen werden anhand von Bildern, die Anwendung anhand von Beispielen dargestellt.  相似文献   

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