http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/6535 2026-05-21T05:51:51Z http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/7212 Title: First SHRIMP U-Pb zircon dating of granulites from the Kontum massif (Vietnam) and tectonothermal implications Authors: T.N., Nam; Sano, Y.; Terada, K.; Toriumi, M.; P., Van Quynh; L.T., Dung Abstract: The Kontum massif in Central Vietnam represents the largest continuous exposure of crystalline basement of the Indochina craton. The central Kontum massif is chiefly made of orthopyroxene granulites (enderbite, charnockite) and associated rocks of the Kannack complex. Mineral assemblages and geothermobarometric studies have shown that the Kannack complex has severely metamorphosed under granulite facies corresponding to P-T conditions of 800-850?C and 8 ? 1 kbars. Twenty-three SHRIMP II UPb analyses of eighteen zircon grains separated from a granulite sample of the Kannack complex yield ca 254 Ma, and one analysis gives ca 1400 Ma concordant age for a zoned zircon core. This result shows that granulites of the Kannack complex in the Kontum massif have formed from a high-grade granulite facies tectonothermal event of Indosinian age (Triassic). The cooling history and subsequent exhumation of the Kannack complex during Indosinian times ranged from ~850?C at ca 254 Ma to ~300?C at 242 Ma, with an average cooling rate of ~45?C/Ma. (C) 2000 Elsevier Science Ltd. All rights reserved. 2001-01-01T00:00:00Z http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/7209 Title: Normal modes and propagation dynamics in a strongly driven Raman medium Authors: Le, Kien F.; Hakuta, K. Abstract: Using a strong field, the collinear propagation of two weak sidebands was studied in Raman medium in a strong field. The superposition of the sideband fields propagated freely in the medium at the vacuum speed of light. The coupled normal mode determined the effective frequency governing the coherence of the medium. A slow group velocity of light was obtained in far-off-resonance Raman medium for a small effective two-photon detuning. 2001-01-01T00:00:00Z http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/7205 Title: Effect of the crystalline electric field on the Neel temperatures of RCu2 compounds Authors: N.H., Luong; Franse, J.J.M.; N.H., Hai Abstract: Values for the Neel temperature of the RCu2 compounds (R = Tb-Tm) were calculated using a molecular field model including crystalline-electric-field effects as presented by Noakes and Shenoy. The calculated results show that the unusual behavior, at the Neel temperatures, of these compounds can be explained on the basis of this model. 2001-01-01T00:00:00Z http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/7202 Title: Photon-axion conversion cross-sections in an electromagnectic field Authors: Van, Soa D.; H.H., Bang Abstract: Photon-axion conversions in static magnetic fields and in a periodic field with frequency equal to the axion mass are considered in detail by the Feynman diagram methods. The differential cross-sections are presented and numerical evaluations are given. It is shown that there is a resonant conversion for the considered process. Some estimates for experimental conditions are given from our results. 2001-01-01T00:00:00Z