Sectional response of T-shaped RC walls   总被引：1，自引：1，他引：0  

Eleni Smyrou  Timothy Sullivan  Nigel Priestley  Michele Calvi 《Bulletin of Earthquake Engineering》2013,11(4):999-1019

Deformation quantities such as strain, curvature and displacement are of paramount importance in seismic design within a performance-based procedure that aims to control the structural response at predefined levels of inelastic action. Given the importance of curvature expressions independent of strength for the design process, and for the particular case of T-shaped walls, the curvature trends at yield, serviceability and ultimate limit state are determined in graphical and analytical form. The comprehensive set of equations proposed in this work are strength independent and allow the reliable computation of limit-state curvatures, essential in a displacement-based design approach, and thus the realistic estimation of appropriate ductility factors in the design of T-shaped walls. Furthermore, results regarding the section properties of T-shaped walls, such as the elastic stiffness and the moment capacity for opposite directions of loading, offer additional information on T-shaped walls.  相似文献   

Boundary conditions effect on linearized mud-flow shallow model     

Cristiana Di Cristo  Michele Iervolino  Andrea Vacca 《Acta Geophysica》2013,61(3):649-667

The occurrence of roll-waves in mud-flows is investigated based on the formulation of the marginal stability threshold of a linearized onedimensional viscoplastic (shear-thinning) flow model. Since for this kind of non-Newtonian rheological models this threshold may occur in a hypocritical flow, the downstream boundary condition may have a nonnegligible effect on the spatial growth/decay of the perturbation. The paper presents the solution of the 1D linearized flow of a Herschel and Bulkley fluid in a channel of finite length, in the neighbourhood of a hypocritical base uniform flow. Both linearly stable and unstable conditions are considered. The analytical solution is found applying the Laplace transform method and obtaining the first-order analytical expressions of the upstream and downstream channel response functions in the time domain. The effects of both the yield stress and the rheological law exponent are discussed, recovering as particular cases both power-law and Bingham fluids. The theoretical achievements may be used to extend semi-empirical criteria commonly employed for predicting roll waves occurrence in clear water even to mud-flows.  相似文献   

The SAURON project – III. Integral-field absorption-line kinematics of 48 elliptical and lenticular galaxies   总被引：1，自引：0，他引：1  

Eric Emsellem  Michele Cappellari  Reynier F. Peletier  Richard M. McDermid  R. Bacon  M. Bureau †  Y. Copin  Roger L. Davies  Davor Krajnovi&#;  Harald Kuntschner  Bryan W. Miller  P. Tim de Zeeuw 《Monthly notices of the Royal Astronomical Society》2004,352(3):721-743

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Star clusters with primordial binaries – II. Dynamical evolution of models in a tidal field     

Michele Trenti  Douglas C. Heggie  Piet Hut 《Monthly notices of the Royal Astronomical Society》2007,374(1):344-356

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The SAURON project – V. Integral-field emission-line kinematics of 48 elliptical and lenticular galaxies     

Marc Sarzi  Jesús Falcón-Barroso  Roger L. Davies  Roland Bacon  Martin Bureau  Michele Cappellari  P. Tim de Zeeuw  Eric Emsellem  Kambiz Fathi  Davor Krajnovi&#;  Harald Kuntschner  Richard M. McDermid  Reynier F. Peletier 《Monthly notices of the Royal Astronomical Society》2006,366(4):1151-1200

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A pre-shock event at Jupiter on 30 January 2001     

Karoly Szego  David T. Young  Bruce Barraclough  Andrew J. Coates  Michele K. Dougherty  Donald A. Gurnett  Andrea Opitz  Michelle F. Thomsen 《Planetary and Space Science》2006,54(2):200-211

In this paper we analyze a pre-shock event that we observed in the foot region of the quasi-parallel bow shock (BS) that the Cassini spacecraft crossed on 30 January 2001, at about 1030 UT. Before crossing the BS, the incoming solar wind first decelerated, and then the bulk velocity both of the proton and α components increased, the flow accelerated and decelerated, heated and cooled several times. We characterize the plasma in the foot using the data measured by the magnetometer, the radio and plasma wave science (RPWS) instrument, and the Cassini plasma spectrometer (CAPS) being carried onboard the Cassini spacecraft, and analyze the observations. We argue that the velocity and temperature changes can be caused by firehose instabilities excited by ions reflected from the shock. We investigate another possibility, shocklet formation, to account for the observed features, but conclude that this explanation seems to be less likely. In the foot we also identified both backstreaming electrons and ions and electrostatic waves in the 100-1000 Hz range very likely excited by the backstreaming electrons.  相似文献   

Geological structure of a long‐living geothermal system,Larderello, Italy     

Giovanni Bertini  Michele Casini  Giovanni Gianelli  Enrico Pandeli 《地学学报》2006,18(3):163-169

We have examined the data of 600 geothermal wells and re‐interpreted approximately 500 km seismic profiles through the field of Larderello, Italy. We conclude that the two main seismic reflectors present below the geothermal area host two different fluids: (1) superheated steam in the upper H‐horizon (reached by drillholes) and (2) supercritical fluid in the deeper K‐horizon (reached by few unproductive or damaged wells). The superheated steam has the physical and chemical connotation of the geothermal fluid exploited so far at Larderello, whereas the supercritical fluid represents a potential unconventional deep‐seated resource still to be assessed. The high temperatures existing in correspondence of the K‐horizon suggest that the silica‐rich rocks are close to a plastic state and the fluids should remain confined in a medium sealed to the confining rocks, unless occasional fluid overpressure and abrupt high strain rates occur.  相似文献   

Saturn's auroral/polar H₃ infrared emission: II. A comparison with plasma flow models     

Tom Stallard  Chris Smith  Henrik Melin  Alan Aylward  Michele Dougherty 《Icarus》2007,191(2):678-690

We present a detailed analysis of the H⁺₃ intensity and velocity profiles crossing Saturn's auroral/polar region, as described by Stallard et al. [Stallard, T., Miller, S., Melin, H., Lystrup, M., Dougherty, M., Achilleos, N., 2007. Icarus 189, 1-13], with a view to understanding the magnetospheric processes with which they are connected. The data are not consistent with the theory that Saturn's main auroral oval is associated with corotation enforcement currents in the middle magnetosphere. This implies that the main auroral oval can be associated with the open-closed field line boundary [Cowley, S.W.H., Bunce, E.J., O'Rourke, J.M., 2004. J. Geophys. Res. 109. A05212]; a third model, by Sittler et al. [Sittler, E.C., Blanc, M.F., Richardson, J.D., 2006. J. Geophys. Res. 111. A06208] associates the main oval with centrifugal instabilities in the outer magnetosphere, but does not make predictions about ionospheric plasma flows with which we can compare our data. We do, however, tentatively identify emission at latitudes lower than the main auroral oval which may be associated with the corotation enforcement currents in the middle magnetosphere. We also find that at latitudes higher than the main auroral oval there is often a region of the ionosphere that is in rigid corotation with the planet. We suggest that this region corresponds to field lines embedded in the centre of the magnetotail which are shielded from the solar wind such that their rotation is controlled only by the neutral atmosphere.  相似文献   

Dynamical modelling of stars and gas in NGC 2974: determination of mass-to-light ratio, inclination and orbital structure using the Schwarzschild method   总被引：1，自引：0，他引：1  

Davor Krajnovi&#;  Michele Cappellari  Eric Emsellem  Richard M. McDermid  P. Tim de Zeeuw 《Monthly notices of the Royal Astronomical Society》2005,357(4):1113-1133

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The SAURON project – XI. Stellar populations from absorption-line strength maps of 24 early-type spirals     

Reynier F. Peletier  Jesús Falcón-Barroso  Roland Bacon  Michele Cappellari  Roger L. Davies  P. T. de Zeeuw  Eric Emsellem  Katia Ganda  Davor Krajnovi&#;  Harald Kuntschner  Richard M. McDermid  Marc Sarzi  Glenn van de Ven 《Monthly notices of the Royal Astronomical Society》2007,379(2):445-468

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