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Summary We propose some approximate, expedite models for calculating the conductive cooling of magmatic intrusions. At great depths,
conduction can account for more cooling than convective phenomena, for tens of thousands of years. Numerical simulation of
the thermal development of a region by explicit Euler method requires an appropriate proportion between the quantizations
of time and space. Only thus can a numerical solution be obtained, which is consistent and stable, and which conforms to the
second law of thermodynamics. In order to account for the geometry and volumetric limits of actual intrusions, we resorted
to cylindrical representations rather than to the Cartesian ones used in the references
Work conducted at the Naval University Institute of Naples under a 1985 grant from the Ministry of Public Education. 相似文献
106.
Hypervalent iodine as good leaving group: oxidative rearrangement of 1-IODO-2-methoxy-2-arylalkanes.
Attilio Citterio Marco Gandolfi Claudio Giordano Graziano Castaldi 《Tetrahedron letters》1985,26(13):1665-1666
A new example of the good leaving group properties of hypervalent iodine is reported: oxidative rearrangement of 1-iodo-2-methoxy-2-arylalkanes 1 (R=alkyl) provides, via 1,2-aryl shift, alkyl benzyl ketones 3 in good yields. 相似文献
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Claudio Giordano Graziano Castaldi Fulvio Uggeri 《Angewandte Chemie (International ed. in English)》1984,23(6):413-419
α-Arylalkanoic acids have acquired importance as anti-inflammatory agents and are now in great demand on the pharmaceutical front. Hence, the need has arisen for new and improved, economical synthetic procedures suitable for their preparation and manufacture on an industrial scale. For many years the synthetic approach to this class of compounds was restricted to the Willgerodt and Darzen reactions. More recently, several methods have been developed which are based on the 1,2-aryl shift in acetals of α-functionalized alkyl aryl ketones. This new approach starts from the oxythallation of alkyl aryl ketones first described by Taylor and McKillop in 1971. Asymmetric syntheses of some important arylakanoic acids have also been developed on this basis. The highly toxic thallium salts may be replaced, inter alia, by catalytically effective metal salts. 相似文献
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Senff D Krüger F Scheidl S Benomar M Sidis Y Demmel F Braden M 《Physical review letters》2006,96(25):257201
The magnon dispersion in the charge, orbital, and spin ordered phase in La1/2Sr3/2MnO4 has been studied by means of inelastic neutron scattering. We find excellent agreement with a magnetic interaction model based on the CE-type superstructure. The magnetic excitations are dominated by ferromagnetic exchange parameters revealing a nearly one-dimensional character at high energies. The strong ferromagnetic interaction in the charge or orbital ordered phase appears to be essential for the capability of manganites to switch between metallic and insulating phases. 相似文献