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61.
Boron concentration data on 69 different biological, coal and geological reference materials issued by NBS, USGS and CCRMP have been collected from 1951-1986. Data from 135 journal articles and technical reports are included. These data are summarized in consensus (mean) values with uncertainties expressed as pm one standard deviation. Mean values are also calculated as a function of analytical procedure and all raw data are given in the tables.  相似文献   
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This is the seventeenth survey in the series of Geochemical Reference Sample (GRS) Bibliography published in Geostandards Newsletter and is designated as Part XVII in the series. Part XVII contains references extracted from major analytical chemistry and geochemistry journals that have become available to the author between January and December 1996. A few earlier ones which were not available at the time of the previous report (Part XVI), together with those which were inadvertently overlooked, have also been included.  相似文献   
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Fifty analyses of rare earth elements as well as mineralogical studies have been carried out on a suite of manganese nodules and crusts from the Central Indian Basin and the Western Indian Ocean. The aim was to identify the processes controlling the REE patterns of the phases hosting the REE in the manganese nodules, with an emphasis on an understanding of the Ce anomaly. This has involved separating the encrusting layers and nuclei physically as well as Fe-Mn oxides from the aluminosilicate phase chemically (using a 2 M HCl leach) prior to analysis.

The presence of nodule nuclei seems to have little influence (mostly <5% to a maximum of 30%) on the overall magnitude of the Ce anomalies in these nodules. The ratios of concentrations of elements in the acid leachates and the corresponding bulk values yield flat REE patterns indicating that the aluminosilicate phase contributes very little to the Ce anomalies. Interelement relations indicate that the Ce anomalies are largely controlled by the amorphous mineral phase FeOOH.xH2O. The relationship of Fe, Ce anomaly and δ-MnO2 further suggests that Ce is chemisorbed onto iron oxyhydroxides which are epitaxially intergrown with δ-MnO2.

The regional distribution of the Ce anomaly values appears to depend on many of the factors responsible for the uptake of other minor metals in nodules and crusts.  相似文献   

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Iwan Williams and Stephen Lowry report on the RAS Specialist Discussion meeting held on 9 December 2005, which considered the historical and current significance of comets.  相似文献   
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This paper presents the results of a numerical investigation in which the maximum response of six hysteretic systems is calculated for an ensemble of twelve earthquakes. Inelastic response spectra are constructed for a range of response ductility. An effective linear period and damping are calculated for each system and ductility by determining those parameters which minimize an RMS response spectrum error. Conclusions are presented concerning the effects of deterioration, stiffness degradation, cracking and ductility on the effective linear system parameters.  相似文献   
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The International Workshop on Strong-motion Earthquake Instrument Arrays was held during 2-5 May 1978 in Honolulu, Hawaii. The goal of the workshop was to develop a workable plan for the possible future deployment of dense strong-motion arrays with primary emphasis on ground motion studies. Topics considered by the workshop included: favourable array locations, the design of arrays for source mechanism and wave propagation studies, the design of arrays for local effects studies, array construction and operation, and implementation. This paper gives a summary of the recommendations and conclusions of the workshop.  相似文献   
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