Full‐scale dynamic response of an RC building under weak seismic motions using earthquake recordings,ambient vibrations and modelling     

Clotaire Michel  Philippe Guguen  Saber El Arem  Jacky Mazars  Panagiotis Kotronis 《地震工程与结构动力学》2010,39(4):419-441

In countries with a moderate seismic hazard, the classical methods developed for strong motion prone countries to estimate the seismic behaviour and subsequent vulnerability of existing buildings are often inadequate and not financially realistic. The main goals of this paper are to show how the modal analysis can contribute to the understanding of the seismic building response and the good relevancy of a modal model based on ambient vibrations for estimating the structural deformation under weak earthquakes. We describe the application of an enhanced modal analysis technique (frequency domain decomposition) to process ambient vibration recordings taken at the Grenoble City Hall building (France). The frequencies of ambient vibrations are compared with those of weak earthquakes recorded by the French permanent accelerometric network (RAP) that was installed to monitor the building. The frequency variations of the building under weak earthquakes are shown to be less (∼2%) and therefore ambient vibration frequencies are relevant over the elastic domain of the building. The modal parameters extracted from ambient vibrations are then used to determine the 1D lumped‐mass model in order to reproduce the inter‐storey drift under weak earthquakes and to fix a 3D numerical model that could be used for strong earthquakes. The correlation coefficients between data and synthetic motion are close to 80 and 90% in horizontal directions, for the 1D and 3D modelling, respectively. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

Adaptation of existing behaviour models to unsaturated states: application to CJS model     

Jean‐Michel Pereira  Henry Wong  Philippe Dubujet  Patrick Dangla 《国际地质力学数值与分析法杂志》2005,29(11):1127-1155

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Network science, NetLander: a european mission to study the planet Mars     

Veronique Dehant  Philippe Lognonné 《Planetary and Space Science》2004,52(11):977-985

The planet Mars has many Earth like characteristics, but its evolution is different. An important future step in Mars’ geophysics is to deploy a network of stations at the surface of Mars inorder to study a wide range of properties of this planet, going from its deep interior structure to its atmosphere. Each ground station (small landers) will contain the same scientific instruments/experiments. The collected data will improve our knowledge of the Martian interior, surface and atmosphere, as well as its evolution. An important part of these objectives can only be achieved by a network of surface stations, as a network gives unique possibilities for performing studies of global scale phenomena and studies requiring simultaneous measurements from several sites.  相似文献   

An update on Archeops: flights and data products     

Jacques Delabrouille  Philippe Filliatre 《Astrophysics and Space Science》2004,290(1-2):119-134

Archeops is a balloon-borne instrument dedicated to measuring cosmic microwave background (CMB) temperature anisotropies at high angular resolution (～ 8 arcminutes) over a large fraction (～ 30%) of the sky in the millimetre domain. The general design is based on Planck High Frequency Instrument (HFI) technology. Bolometers cooled to 0.1 K scan the sky in total power mode along large circles at constant elevation. Archeops is designed to observe a complete annulus on the sky covering all right ascensions between about 25 and 55 degrees during the course of a 24-hour Arctic-night balloon flight, in four frequency bands centered at 143, 217, 353 and 545 GHz. We describe the Archeops flights and the data products obtained during the three successful flights from Trapani (Sicily) to Spain in July 1999, and from Kiruna (Sweden) to Russia in January 2001 and February 2002. We discuss present Archeops results and the future use of Archeops data.  相似文献   

The SIMBOL-X hard X-ray mission     

Giovanni Pareschi  Philippe Ferrando 《Experimental Astronomy》2005,20(1-3):139-149

SIMBOL-X is a hard X-ray mission based on a formation flight architecture, operating in the 0.5–80 keV energy range, which has been selected for a comprehensive Phase A study, being jointly carried out by CNES and ASI. SIMBOL-X makes uses of a long (in the 25–30 m range) focal length multilayer-coated X-ray mirrors to focus for the first time X-rays with energy above 10 keV, resulting in at least a two orders of magnitude improvement in angular resolution and sensitivity compared to non focusing techniques used so far. The SIMBOL-X revolutionary instrumental capabilities will allow us to elucidate outstanding questions in high energy astrophysics, related in particular to the physics and energetic of the accretion processes on-going in the Universe, also performing a census of black holes on all scales, achieved through deep, wide-field surveys of extragalactic fields and of the Galactic center, and the to the acceleration of electrons and hadrons particles to the highest energies. In this paper, the mission science objectives, design, instrumentation and status are reviewed. PACS: 95.55 – Astronomical and space-research instrumentation 95.85 – Astronomical Observations 98.85.Nv – X-ray  相似文献   

Low‐temperature crystallization of MgSiO3 glasses under electron irradiation: Possible implications for silicate dust evolution in circumstellar environments     

Philippe CARREZ  Karine DEMYK  Hugues LEROUX  Patrick CORDIER  Anthony P. JONES  Louis D'HENDECOURT 《Meteoritics & planetary science》2002,37(11):1615-1622

Abstract— Synthetic MgSiO₃ glasses were irradiated at room temperature by 300 keV electrons in a transmission electron microscope (TEM). One of the samples had been previously irradiated by 50 keV He+ ions. Electron irradiation induces the nucleation and growth of randomly oriented nanometer‐sized crystallites. The crystallites first consist of MgO and subsequently of forsterite (Mg₂SiO₄). Both are seen to form within an amorphous SiO₂ matrix. The rate of crystallization of the samples has been monitored by conventional TEM imaging and electron diffraction. The sample that had been pre‐irradiated with He+ ions is found to transform faster than the as‐quenched glass. The crystallization of metastable MgSiO₃ glasses is explained by ionizing radiation‐induced elemental diffusion that allows the reorganization of matter into a more favourable thermodynamic state. These results show that ionizing radiation interactions could account for crystal formation as observed in infrared spectroscopy in some young stellar environments.  相似文献   

Submillimeter Studies of Prestellar Cores and Protostars: Probing the Initial Conditions for Protostellar Collapse     

Philippe André  Jeroen Bouwman  Arnaud Belloche  Patrick Hennebelle 《Astrophysics and Space Science》2004,292(1-4):325-337

Improving our understanding of the earliest stages of star formation is crucial to gain insight into the origin of stellar masses, multiple systems, and protoplanetary disks. We discuss recent advances made in this area, thanks to submillimeter mapping observations with large single-dish telescopes and interferometers. Although ambipolar diffusion appears to be too slow cores, there is nevertheless good evidence that the gravitational collapse of isolated protostellar cores is strongly magnetically controlled. We also argue that the beginning of protostellar collapse is much more violent in cluster-forming clouds than in regions of distributed star formation.  相似文献   

4. Building of a Habitable Planet     

Hervé Martin  Francis Albarède  Philippe Claeys  Muriel Gargaud  Bernard Marty  Alessandro Morbidelli  Daniele L. Pinti 《Earth, Moon, and Planets》2006,98(1-4):97-151

Except the old Jack Hills zircon crystals, it does not exit direct record of the first 500 Ma of the Earth history. Consequently, the succession of events that took place during this period is only indirectly known through geochemistry, comparison with other telluric planets, and numerical modelling. Just after planetary accretion several episodes were necessary in order to make life apparition and development possible and to make the Earth surface habitable. Among these stages are: the core differentiation, the formation of a magma ocean, the apparition of the first atmosphere, oceans and continents as well as the development of magnetic field and of plate tectonics. In the same time, Earth has been subject to extraterrestrial events such as the Late Heavy Bombardment (LHB) between 3.95 and 3.8 Ga. Since 4.4–4.3 Ga, the conditions for pre-biotic chemistry and appearance of life were already met (liquid water, continental crust, no strong meteoritic bombardment, etc...). This does not mean that life existed as early, but this demonstrates that all necessary conditions assumed for life development were already present on Earth.  相似文献   

Succession of Permian and Mesozoic metasomatic events in the eastern Pyrenees with emphasis on the Trimouns talc–chlorite deposit     

Alexandre Boutin  Michel de Saint Blanquat  Marc Poujol  Philippe Boulvais  Philippe de Parseval  Caroline Rouleau  Jean-François Robert 《International Journal of Earth Sciences》2016,105(3):747-770

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Fluorapatite in carbonatite-related phosphate deposits: the case of the Matongo carbonatite (Burundi)     

Sophie Decrée  Philippe Boulvais  Luc Tack  Luc André  Jean-Marc Baele 《Mineralium Deposita》2016,51(4):453-466

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