The plane of the Edgeworth-Kuiper belt     

Simon J. Collander-Brown  Iwan P. Williams 《Icarus》2003,162(1):22-26

We examine possible locations for the primordial disk of the Edgeworth-Kuiper Belt (EKB), using several subsets of the known objects as markers of the total mass distribution. Using a secular perturbation theory, we find that the primordial plane of the EKB could have remained thin enough to escape detection only if it is clustered very closely about the invariable plane of the Solar System.  相似文献   

GeostandaRef Corner Geochemical Reference Sample Bibliography for 2000     

Iwan Roelandts 《Geostandards and Geoanalytical Research》2002,26(1):101-120

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Statistical performance analysis of seismic‐excited structures with active interaction control     

Yunfeng Zhang  Wilfred D. Iwan 《地震工程与结构动力学》2003,32(7):1039-1054

This paper presents a statistical performance analysis of a semi‐active structural control system for suppressing the vibration response of building structures during strong seismic events. The proposed semi‐active mass damper device consists of a high‐frequency mass damper with large stiffness, and an actively controlled interaction element that connects the mass damper to the structure. Through actively modulating the operating states of the interaction elements according to pre‐specified control logic, vibrational energy in the structure is dissipated in the mass damper device and the vibration of the structure is thus suppressed. The control logic, categorized under active interaction control, is defined directly in physical space by minimizing the inter‐storey drift of the structure to the maximum extent. This semi‐active structural control approach has been shown to be effective in reducing the vibration response of building structures due to specific earthquake ground motions. To further evaluate the control performance, a Monte Carlo simulation of the seismic response of a three‐storey steel‐framed building model equipped with the proposed semi‐active mass damper device is performed based on a large ensemble of artificially generated earthquake ground motions. A procedure for generating code‐compatible artificial earthquake accelerograms is also briefly described. The results obtained clearly demonstrate the effectiveness of the proposed semi‐active mass damper device in controlling vibrations of building structures during large earthquakes. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

1987 Compilation of Elemental Concentration Data for USGS BIR-1, DNC-1 and W-2     

Ernest S. GLADNEY  Iwan ROELANDTS 《Geostandards and Geoanalytical Research》1988,12(1):63-118

Elemental concentration data on up to 73 individual constituents in BIR-1, DNC-1, and W-2 have been collected from 94 journal articles and technical reports. These data are summarized in consensus (mean) values with uncertainties expressed as one standard deviation. Mean values are also calculated as a function of analytical procedure and all raw data are given in the tables.
Ce rapport rassemble des données analytiques sur 73 éléments dans trois échantillons, BIR-1, DNC-1 et W-2, publiées dans 94 articles scientifiques ou rapports techniques. Quand cela a été possible, les valeurs de consensus (moyenne) sont présentées pour chaque élément avec l'incertitude exprimée un écart-type. Des valeurs moyennes en fonction des procédures analytiques sont également présentées.  相似文献   

Inductively Coupled Plasma Determination Of Nine Rare-Earth Elements In Sixty International Geochemical Reference Samples   总被引：2，自引：0，他引：2  

Iwan ROELANDTS 《Geostandards and Geoanalytical Research》1990,14(1):137-147

Data for nine rare-earth elements (REE) determined by inductively coupled plasma spectrometry (ICP-AES) in sixty international geochemical reference samples (igneous and sedimentary rocks, soils and sediments) are presented. The method is based on acid digestion of the sample and cation-exchange separation from matrix elements. Good agreement is generally achieved between the results of this work and the recent compilation values. The present paper includes analytical data on several reference materials for which existing data are rather scarce or even inexistent  相似文献   

1988 Compilation of Elemental Concentration Data for USGS Geochemical Exploration Reference Materials GXR-1 to GXR-6     

Ernest S. GLADNEY  Iwan ROELANDTS 《Geostandards and Geoanalytical Research》1990,14(1):21-118

Concentration data on 73 individual constituents in United States Geological Survey (USGS) Geochemical Exploration Reference Materials GXR-1 to GXR-6 have been collected from 131 journal articles and technical reports. These data are summarized as consensus (mean) values with uncertainties expressed as one standard deviation. Mean values are also calculated as a function of analytical procedure and all raw data are given in the tables. Recommended values are proposed based upon data criteria used by NIST (National Institute of Standards and Technology, formerly the National Bureau of Standards or NBS).  相似文献   

1988 Compilation of Elemental Concentration Data for USGS Basalt BCR-1     

Ernest S. GLADNEY  Elizabeth A. JONES  Eric J. NICKELL  Iwan ROELANDTS 《Geostandards and Geoanalytical Research》1990,14(2):209-359

Concentration data on up to 82 individual constituents in USGS Basalt BCR-1 have been collected from 1395 journal articles and technical reports. These data are summarized in consensus (mean) values with uncertainties expressed as ± one standard deviation. Mean values are also calculated as a function of analytical procedure and all raw data are given in the tables. Recommended values are proposed based upon data criteria used by NIST (National Institute of Standards and Technology, formerly the National Bureau of Standards or NBS).  相似文献   

Response variability in structural dynamics     

H. Jensen  W. D. Iwan 《地震工程与结构动力学》1991,20(10):949-959

This paper presents a technique for treating uncertainties in the dynamic models of a structural system. The formulation of the method is presented for a simple case of a single-degree-of-freedom linear oscillator. The uncertainties are modelled as random variables and are assumed to be time-independent. The solution is expanded as a series involving the random terms, and a system of linear ordinary differential equations for the unknowns of the problem is derived using the weighted residual method. The system of equations is then integrated in time and the response variability is computed. Validation calculations show that the results from the method agree well with those obtained by other solution techniques. Finally, some possible applications and extensions of the present work are discussed.  相似文献   

Geochemical Reference Sample BIBLIOGRAPHY FOR 1993     

Iwan ROELANDTS 《Geostandards and Geoanalytical Research》1994,18(2):301-325

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1983 Compilation of Elemental Concentration Data for Samples SO-1 to SO-4     

Ernest S. GLADNEY  Colleen E. BURNS  Iwan Roelandts 《Geostandards and Geoanalytical Research》1985,9(1):35-68

Concentration data for as many as 72 constituents in the four Canadian Certified Reference Materials Project (CCRMP) soil samples have been collected from journal articles and technical reports published since these soil standards were issued in 1978. These data are summarized into mean +/- one standard deviation values and compared with available certification data from CCRMP. All literature data located or calculated are presented in the appendices.  相似文献