Le Tchad depuis 25 000 ans. Géologie—Archéologie— Hydrogéologie. Jean-Louis Schneider. Publisher Masson,Paris 1994 (134 pp) 149FF ISBN 2 225 84335 X     

Jaume Bordonau 《第四纪科学杂志》1995,10(2):191-192

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Central configurations of the planar 1+N body problem     

Josefina Casasayas  Jaume Llibre  Ana Nunes 《Celestial Mechanics and Dynamical Astronomy》1994,60(2):273-288

In this paper, we give a new derivation of the equations for the central configurations of the 1+n body problem. In the case of equal masses, we show that forn large enough there exists only one solution. Our lower bound forn improves by several orders of magnitude the one previously found by Hall.  相似文献   

Periodic Orbits of a Collinear Restricted Three-Body Problem   总被引：6，自引：0，他引：6  

Montserrat Corbera  Jaume Llibre 《Celestial Mechanics and Dynamical Astronomy》2003,86(2):163-183

In this paper we study symmetric periodic orbits of a collinear restricted three-body problem, when the middle mass is the largest one. These symmetric periodic orbits are obtained from analytic continuation of symmetric periodic orbits of two collinear two-body problems.  相似文献   

Equilibrium Points and Central Configurations for the Lennard-Jones 2- and 3-Body Problems   总被引：1，自引：1，他引：0  

Montserrat Corbera  Jaume Llibre  Ernesto Pérez-Chavela 《Celestial Mechanics and Dynamical Astronomy》2004,89(3):235-266

In this paper we study the relative equilibria and their stability for a system of three point particles moving under the action of a Lennard-Jones potential. A central configuration is a special position of the particles where the position and acceleration vectors of each particle are proportional, and the constant of proportionality is the same for all particles. Since the Lennard-Jones potential depends only on the mutual distances among the particles, it is invariant under rotations. In a rotating frame the orbits coming from central configurations become equilibrium points, the relative equilibria. Due to the form of the potential, the relative equilibria depend on the size of the system, that is, depend strongly of the momentum of inertia I. In this work we characterize the relative equilibria, we find the bifurcation values of I for which the number of relative equilibria is changing, we also analyze the stability of the relative equilibria. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Stochastic Modeling of the Residual Acceleration Field in a Microgravity Environment     

Jaume Casademunt  Jorge Viñals 《Astrophysics and Space Science》2001,276(1):123-133

We discuss fluid flows induced by thehigh-frequency components of the residual acceleration field onboard spacecraft (g-jitter) on representative experimental configurations.We study the statistics of g-jitter time series data from theNASA SL-J mission (SAMS-258), and discuss a recently introducedstochastic model of g-jitter. The examples studied are chosen to highlightintrinsically stochastic effects of g-jitter. They include free surfaceresonances, cavity flow, and inertial Brownian motion in suspensions. Thelatter is relevant for coarsening experiments in solid-liquid mixtures.  相似文献   

The global flow of the parabolic restricted three-body problem     

Josep M. Cors  Jaume Llibre 《Celestial Mechanics and Dynamical Astronomy》2004,90(1-2):13-33

We have two mass points of equal masses m ₁=m ₂ > 0 moving under Newton’s law of attraction in a non-collision parabolic orbit while their center of mass is at rest. We consider a third mass point, of mass m ₃=0, moving on the straight line L perpendicular to the plane of motion of the first two mass points and passing through their center of mass. Since m ₃=0, the motion of m ₁ and m ₂ is not affected by the third and from the symmetry of the motion it is clear that m ₃ will remain on the line L. The parabolic restricted three-body problem describes the motion of m ₃. Our main result is the characterization of the global flow of this problem.  相似文献   

Hip-hop solutions of the 2N-body problem     

Esther Barrabés  Josep Maria Cors  Conxita Pinyol  Jaume Soler 《Celestial Mechanics and Dynamical Astronomy》2006,95(1-4):55-66

Hip-hop solutions of the 2N-body problem with equal masses are shown to exist using an analytic continuation argument. These solutions are close to planar regular 2N-gon relative equilibria with small vertical oscillations. For fixed N, an infinity of these solutions are three-dimensional choreographies, with all the bodies moving along the same closed curve in the inertial frame.  相似文献   

GPR survey to confirm the location of ancient structures under the Valencian Cathedral (Spain)     

Vega Prez Gracia  Jos Antonio Canas  Lluis G. Pujades  Jaume Claps  Oriol Caselles  Francesc García  Raul Osorio 《Journal of Applied Geophysics》2000,43(2-4)

This paper describes the ground-penetrating radar (GPR) survey performed inside the Cathedral of Valencia, Spain. It is part of historical studies performed in the Cathedral in order to add information to old maps and documents in the Cathedral Archives and also to analyze the extent and importance of potentially destructive moisture areas that were appearing on the floor. The construction of the Cathedral of Valencia occurred in three stages, all of which are well-documented in the Cathedral Archives with detailed drawings, maps, and charts. The radar data were successful in locating crypts, ossuaries, sepulchers, and graves, and the location of ancient walls that existed before the final Cathedral expansion. Three cultural layers corresponding to the three periods of construction were also identified corresponding to the Roman, Arabian and Middle Age Epochs. Measurements of relative sub-floor moisture were obtained by comparing dielectric permittivity changes and radar velocity differences between materials in humid and non-humid areas.  相似文献   

Brane cosmology from observational surveys and its comparison with standard FRW cosmology     

Artyom V. Astashenok  Emilio Elizalde  Jaume de Haro  Sergei D. Odintsov  Artyom V. Yurov 《Astrophysics and Space Science》2013,347(1):1-13

Several simple dark energy models on the brane are investigated. They are compared with corresponding models in the frame of 4d Friedmann-Robertson-Walker cosmology. For constraining the parameters of the models considered, recent observational data, including SNIa apparent magnitude measurements, baryon acoustic oscillation results, Hubble parameter evolution data and matter density perturbations are used. Also, explicit formulas of the so-called state-finder parameters in teleparallel theories are found that could be useful to test these models and compare Loop Quantum Cosmology and Brane Cosmology. The conclusion is reached that a joint analysis as the one developed here allows to estimate, in a very clear way, possible deviation of our cosmology from the standard Friedmann-Robertson-Walker one.  相似文献   

Towards a quantum universe     

Jaume Giné 《Astrophysics and Space Science》2012,339(1):25-30

In this short review we study the state of the art of the great problems in cosmology and their interrelationships. The reconciliation of these problems passes undoubtedly through the idea of a quantum universe.  相似文献