A Method to Suppress Isobaric and Polyatomic Interferences for Measurements of Highly Siderophile Elements in Desilicified Geological Samples     

Xiaoyu Zhou  Ryoji Tanaka  Masahiro Yamanaka  Chie Sakaguchi  Eizo Nakamura 《Geostandards and Geoanalytical Research》2019,43(4):611-633

Sample decomposition using inverse aqua regia at elevated temperatures and pressures (e.g., Carius tube or high‐pressure asher) is the most common method used to extract highly siderophile elements (HSEs: Ru, Rh, Pd, Re, Os, Ir, Pt and Au) from geological samples. Recently, it has been recognised that additional HF desilicification is necessary to better recover HSEs, potentially contained within silicate or oxide minerals in mafic samples, which cannot be dissolved solely by inverse aqua regia. However, the abundance of interfering elements tends to increase in the eluent when conventional ion‐exchange purification procedures are applied to desilicified samples. In this study, we developed an improved purification method to determine HSEs in desilicified samples. This method enables the reduction of the ratios of isobaric and polyatomic interferences, relative to the measured intensities of HSE isotope masses, to less than a few hundred parts per million. Furthermore, the total procedural blanks are either comparable to or lower than conventional methods. Thus, this method allows accurate and precise HSE measurements in mafic and ultramafic geological samples, without the need for interference corrections. Moreover, the problem of increased interfering elements, such as Zr for Pd and Cr for Ru, is circumvented for the desilicified samples.  相似文献   

On the dynamics of rotating fluids and planetary atmospheres: A summary of some recent work     

Raymond Hide 《Pure and Applied Geophysics》1983,121(3):365-374

An outline is given of some recent and current research in the Geophysical Fluid Dynamics Laboratory of the UK Meteorological Office, on the dynamics of rotating fluids and planetary atmospheres. Many of these investigations bear on the problem of creating a theoretical framework for atmospheric predictability studies.  相似文献   

Origin of Jupiter's Magnetic Field     

R. Hide 《Geophysical Journal International》1975,41(3):347-348

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On the magnetic flux linkage of an electrically-conducting fluid     

R. Hide 《地球物理与天体物理流体动力学》2013,107(1):171-176

Abstract

A method has recently been proposed for finding the radius r_c of the electrically-conducting fluid core of a planet of outer radius r_s from observations of the magnetic field B in the accessible region near or well above the surface of the planet (Hide, 1978). The method is based on the supposition that when the magnetic field is produced by hydromagnetic dynamo action in the core, implying that the magnetic Reynolds number R there is large, (a) fluctuations in B can occur everywhere on the comparatively short advective time-scale τ _A associated with fluid motions in the core and so can fluctuations in the quantity N, defined for any closed surface S as the total number of intersection of magnetic lines of force with S, provided that S lies well outside the core, but (b) at the surface of the core, where lines of magnetic force emerge from their region of origin, concomitant fluctuations in N are negligibly small, of the order of τ _A/τ_O where τ _O (= Rτ_A ) is the Ohmic decay time of the core.

A proof of this supposition follows directly from the general expression derived in the present paper showing that when S is a material surface the time rate of change of N is equal to minus twice the line integral of the current density divided by the electrical conductivity around all the lines on S where the magnetic field is tangential to S. This expression (which Palmer in an accompanying paper rederives and extends to the relativistic case using the mathematical formalism of Cartan’s exterior calculus) also provides a direct demonstration of the well-known result that although high electrical conductivity, sufficient to make R ? 1, is a necessary condition for hydromagnetic dynamo action, such action is impossible in a perfect conductor, when R→ ∞.  相似文献