First evidence of IMF control of Jovian magnetospheric boundary locations: Cassini and Galileo magnetic field measurements compared     

Margaret G. Kivelson  David J. Southwood 《Planetary and Space Science》2003,51(13):891-898

The Cassini spacecraft, en route to Saturn, passed close to Jupiter while the Galileo spacecraft was completing its 28th and 29th orbits of Jupiter, thus offering a unique opportunity for direct study of the solar wind-Jovian interaction. Here evidence is given of response of the Jovian magnetopause and bow shock positions to changes of the north-south component of the solar wind magnetic field, a phenomenon long known to occur in equivalent circumstances at Earth. The period analyzed starts with the passage over Cassini of an interplanetary shock far upstream of Jupiter. The shock's arrival at Galileo on the dusk-flank of the magnetosphere caused Galileo to exit into the solar wind. Using inter-spacecraft timing based on the time delay established from the shock arrival at each spacecraft, we point out that Galileo's position with respect to the Jovian bow shock appears to correlate with changes in the disturbed north-south reversing field seen behind the shock. We specifically rule out the alternative of changes in the shape of the bow shock with rotations of the interplanetary magnetic field as the cause.  相似文献   

Periodic flares in the methanol maser source G9.62+0.20E     

S. Goedhart  M. J. Gaylard  D. J. van der Walt 《Monthly notices of the Royal Astronomical Society》2003,339(4):L33-L36

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Gravitational waves from newly born, hot neutron stars     

V. Ferrari  G. Miniutti  J. A. Pons 《Monthly notices of the Royal Astronomical Society》2003,342(2):629-638

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A hydrology modelling framework for the Mackenzie GEWEX programme     

A. Pietroniro  E. D. Soulis 《水文研究》2003,17(3):673-676

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Optical flashes and very early afterglows in wind environments     

X. F. Wu  Z. G. Dai  Y. F. Huang  T. Lu 《Monthly notices of the Royal Astronomical Society》2003,342(4):1131-1138

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Symplectic Mappings of Co-orbital Motion in the Restricted Problem of Three Bodies     

Zsolt Sándor  Bálint Érdi  Carl D. Murray 《Celestial Mechanics and Dynamical Astronomy》2002,84(4):355-368

The dynamics of co-orbital motion in the restricted three-body problem are investigated by symplectic mappings. Analytical and semi-numerical mappings have been developed and studied in detail. The mappings have been tested by numerical integration of the equations of motion. These mappings have been proved to be useful for a quick determination of the phase space structure reflecting the main characteristics of the dynamics of the co-orbital problem.  相似文献   

Book review     

D. W. Connell  Thomas M. Baugh 《Estuaries and Coasts》1992,15(2):255-255

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Isolation of resonance in acoustic backscatter from elastic targetsusing adaptive estimation schemes     

Azimi-Sadjadi  M.R. Wilbur  J. Dobeck  G.J. 《Oceanic Engineering, IEEE Journal of》1995,20(4):346-353

It has been shown that at certain frequencies the acoustic backscatter from elastic targets exhibits certain resonance behavior which closely relates to the physical properties of the target such as dimension, thickness, and composition. The purpose of this paper is to develop an automated approach for identifying the presence of resonance in the acoustic backscatter from an unknown underwater target by isolating the resonance part from the specular contribution. An adaptive transversal filter structure is used to estimate the specular part of the backscatter and consequently the error signal would provide an estimate of the resonance part. An important aspect of this scheme lies in the fact that it does not require an underlying model for the elastic return. The adaptation rule is based upon fast recursive least squares (RLS) learning. The approach taken in this paper is general in the sense that it can be applied to targets of unknown geometry and thickness and, further, does not require any a priori information about the target and/or the environment. Test results on acoustic data are presented which indicate the effectiveness of the proposed approach  相似文献   

Radial velocity searches for other planetary systems:Current status and future prospects     

W. D. Cochran  A. P. Hatzes 《Astrophysics and Space Science》1996,241(1):43-60

Measurement of variations in the radial velocities of stars due to the reflex orbital motion of the star around the planetary-system barycenter constitutes a powerful method of searching for substellar or planetary mass companions. After several years of patient data acquisition, radial-velocity searches for planetary systems around other stars are now beginning to bear fruit. In late 1995 and early 1996, three candidate systems were announced with Jovian-mass planets around solar-type stars. The current paradigm for low-mass star formation suggests that planetary systems should be able to form in the circumstellar disks surrounding young stellar objects. These newly discovered systems, and other discoveries which will soon follow them, will test critically our understanding of the processes of star- and planet-formation. We review the techniques used in these radial-velocity searches and their results to date. We then discuss planned improvements in the surveys, and the prospects for the next 20 years.  相似文献   

Boundary Conditions and Efficient Solution Algorithms For the Potential Function Formulation of the 3-D Viscous Flow Equations     

G. A. Houseman 《Geophysical Journal International》1990,100(1):33-38

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