Thermodynamics of multicomponent pyroxenes: III. Calibration of Fe2+(Mg)-1, TiAl2(MgSi2)-1, TiFe 2 3+ (MgSi2)-1, AlFe3+(MgSi)-1, NaAl(CaMg)-1, Al2(MgSi)-1 and Ca(Mg)-1 exchange reactions between pyroxenes and silicate melts

A thermodynamic model for the Gibbs free energy of igneous pyroxenes with the general formula [Na, Ca, Fe²⁺, Mg]^M2[Fe²⁺, Mg, Ti, Al, Fe³⁺]^M1[Al, Fe³⁺, Si]^TetSiO₆ is calibrated from experimentally determined compositions of coexisting pyroxene and silicate melt. The model is based upon the general formulation, and relies upon the calibration of the “quadrilateral” subsystem, previously published by the present authors. The calibration database of pyroxene-liquid equilibria spans a broad spectrum of temperature, pressure and oxygen fugacity conditions, ranging from 1000°–1600°C, 0.001–30 kbar and iron-wüstite to air. Chemical potentials of endmember pyroxene components as well as exchange potentials between pyroxenes and coexisting liquids are defined utilizing the present authors' thermodynamic melt model. Model parameters are extracted from these relations by regression analysis. The resulting model and derivative endmember properties are internally consistent with an existing standard state thermodynamic database. The success of the model and its applicability to igneous petrogenesis are demonstrated by comparing calculated and experimentally determined liquidus compositions, temperatures and symmetry states for pyroxenes crystallizing from a variety of silicate melts, ranging in composition from tholeiites and angrites through rhyolites to potash ankaratrites.     

富含Na~ 、Ca~(2 )、Al~(3 )、Cr~(3 )蒙脱石对垃圾渗滤液中有机物的吸附

由于层间含有高价态金属阳离子的蒙脱石对特定有机物的吸附能力可大大增强 ,故分别用层间含有Na 、Ca2 、Al3 和Cr3 的蒙脱石对垃圾渗滤液中的有机物进行吸附实验 ,研究它们吸附苯酚、二甲苯和COD的能力及离子形态对吸附效果的影响。结果表明 ,含高价金属阳离子的蒙脱石对苯酚和COD的吸附能力较高 ,吸附能力由小到大的顺序为 :Na 相似文献   

Book Review: Fractals and Chaos in Geology and Geophysics (2nd Edition) By Donald L. Turcotte Cambridge University Press,Cambridge, 1997, 398 p., $90.00/$42.95 (U.S.) ISBN 0-521-56164-7 (hardback), 0-521-56733-5 (paperback)

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Book Review: Symmetry Methods for Differential Equations: A Beginner's Guide. By Peter E. Hydon,Cambridge University Press,Cambridge, 2000, 213 p. +xi, $74.95 (hardback) ISBN 0-521-49703-5, $29.95 (paperback) ISBN 0-521-49786-8

Mathematical Geosciences -