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We suggest a model to consistently describe the available experimental data on the elemental cosmic-ray energy spectra obtained in direct measurements and to make a smooth transition to the spectrum of all particles measured with extensive air showers. The model suggests the existence of three classes of cosmic-ray sources—shocks from supernova explosions that produce power-law rigidity spectra with different maximum rigidities and different spectral indices. The shocks from high-mass supernovae exploding in OB associations are assumed to be the most powerful class of sources. This class of sources accelerates cosmic rays to a maximum rigidity of 4 × 1015 V. The shocks from nonassociated supernovae exploding into a random interstellar medium are assumed to be the next class (in order of decreasing power). This class of sources accelerates cosmic rays to a maximum rigidity of 5 × 1013 V. The third, weakest class of sources is assumed to accelerate cosmic rays to a maximum rigidity of 2 × 1011 V. Nova explosions could be possible physical objects in this class.  相似文献   
2.
A modified Laplacian technique is described for initial orbit determination of asteroids from CCD observations and its applications for orbit determination of the main belt asteroids and near Earth asteroids. The proposed modification is based on a simultaneous improvement of both the orbital elements and the derivatives of spherical coordinates in frames of Laplace's method. It provides an orbit which represents the used observations with the residuals comparable with errors of these observations. The improved values of the derivatives might be used as ephemeris parameters for identification of newly discovered objects.  相似文献   
3.
Titanium is a rare, secondary nucleus among Galactic cosmic rays. Using the Silicon matrix in the ATIC experiment, Titanium has been separated. The energy dependence of the Ti to Fe flux ratio in the energy region from 5 GeV per nucleon to about 500 GeV per nucleon is presented. The article was translated by the authors.  相似文献   
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