共查询到20条相似文献,搜索用时 31 毫秒
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John R. Percy 《Experimental Astronomy》1994,5(1-2):121-128
The role of amateurs and small-scale equipment in astronomical photometry is reviewed. The value of suitably selected projects for both research and educational purposes is stressed. Recent technical developments are noted, and a brief extrapolation to possible future arrangements included.Keynote address at the conference 相似文献
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Earth, Moon, and Planets - 相似文献
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A multivariate particle classification approach is proposed and applied to the analysis of the data from H.E.S.S. (High Energy Stereoscopic System). The combination of results from the three shower reconstruction methods: Hillas, model and 3D-model, leads to a substantial gain in the discrimination power between photons and hadrons. The construction and use of a combined effective estimator improves by several factors the signal-to-background ratio which is extremely important in case of studies of the faint and extended sources. The results of this approach are presented for a typical set of sources. The consequent gain in the sensitivity is shown through a comparison to the H.E.S.S. published results. 相似文献
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P. C. Kendall 《Planetary and Space Science》1970,18(12):1671-1672
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Michael E. Lipschutz Brodie Spaulding Brian D. Kinzie Solomon Gartenhaus 《Meteoritics & planetary science》1993,28(2):240-242
Abstract We describe the circumstances of fall of a 0.5-kg meteorite that landed in Noblesville, Indiana, USA, 3.6 m in front of two witnesses on 1991 August 31. Provisional assessment of Noblesville as an H chondrite is confirmed by data reported elsewhere which demonstrate that it is a regolith breccia with unusual properties. 相似文献
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Earth, Moon, and Planets - 相似文献
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H. Claes 《Celestial Mechanics and Dynamical Astronomy》1980,21(2):193-198
The problem of A.T.E.A.S. is treated, for the zonal perturbations, in its Hamiltonian form. The method consists in eliminating angular variables from the Hamiltonian function. Nearly identity canonical transformations are used, first to remove short periodic terms, second to remove long periodic terms. The general solution, up toJ
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, is represented by the generators of the transformations and by the mean motions of averaged variables, known up toJ
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. Open expressions in the eccentricity are avoided as far as possible. It permits to obtain a closed second order theory with closed third order mean motions.Proceedings of the Sixth Conference on Mathematical Methods in Celestial Mechanics held at Oberwolfach (West Germany) from 14 to 19 August, 1978. 相似文献
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