共查询到20条相似文献，搜索用时 46 毫秒
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讨论了云南天文台１９９５年研制的斑点象探测系统存在的几个问题：ＩＣＣＤ探测的一些性能参数不明,控制器不灵,数据的采集速度较慢等,然后报导了对ＩＣＣＤ光灵敏度和电子快门参数的测量;对ＩＣＣＤ控制器的改装和提高数据采集速度的方法以及用改进后的探测系统进行观测的情况 相似文献
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Paul S. Wesson 《Earth, Moon, and Planets》1981,24(3):339-343
A brief review of electrostatic image forces between dust grains is given. Some comments are then made as to where these forces are significant and where they are not significant. Their significant roles are: (i) in aiding accretion where there is amixed population of charged and uncharged grains; (ii) in providing a fractionation mechanism for metals and silicates where all the grains are charged with thesame sign; (iii) in assuring that two grains which come into contact stick to each other. Some shortcomings in recent articles are pointed out. 相似文献
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Carlotta Bonoli 《Astrophysics and Space Science》1983,89(2):377-385
Some remarks on the use of derivative spectroscopy in astronomy are considered. The advantages and the problems which arise with this technique are outlined. 相似文献
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E. Zsoldos 《Astronomische Nachrichten》1984,305(1):33-35
Some possible causes of scatter in the PLC relation of cepheids are investigated and estimates arising from the presence of rotation, magnetic field, and companion star are presented. 相似文献
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S. B. Charnley 《Astrophysics and Space Science》1995,224(1-2):439-440
Some results from studies of the gas-grain chemistry in oxygen-rich circumstellar envelopes (CSEs) are presented. 相似文献
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Tentatives to detect chaos in variable stars are presented. Constraints on the accuracy on individual measurements and length of the records, necessary to obtain defenitive conclusions, are discussed. Some directions for future improvements are sketched. 相似文献
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Some hypersurface-homogeneous cosmological models with bulk viscous fluid and time-dependent cosmological term are investigated.
These expanding, shearing and non-rotating cosmological models of the universe evolve from initial big-bang singularities
and give an essentially empty space for large times. Some physical and geometric behaviors of these models are also discussed. 相似文献
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K. Shanthi V. U. M. Rao D. R. K. Reddy R. Venkateswarlu 《Astrophysics and Space Science》1991,175(2):241-245
Spatially-homogeneous and anisotropic-vacuum Bianchi type-III cosmological models are obtained in scalar-tensor theories of gravitation proposed by Ross and Dunn. Some physical properties of the models are also discussed. 相似文献
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The exact Bianchi type-II vacuum- and stiff-fluid cosmological models, in the presence of zero-mass scalar fields, are obtained. Some physical properties of the models are also discussed. 相似文献
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综合河外射电源表的编制方法评述 总被引：1，自引：0，他引：1
简要介绍了编制综合外射电源表的几处方法，分析了它们各自的特点。详细讨论了ＩＥＲＳ编制方法及其系列综合表中存在的一些问题，并这些问题提出了一些改进意见。 相似文献
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Exact Bianchi types-II, VIII and IX cosmological models are obtained in the scale covariant theory of gravitation. Some physical and geometrical properties of the models are studied. 相似文献
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本文给出了包含５６个Ｘ选择的ＢＬＬａｃ天体（ＸＢＬｓ）的完备样品，得到了一些相互关系并讨论了ＸＢＬｓ的一些性质。 相似文献
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The 1980–1981U, B, andV observations of the eclipsing binary BZ Eridani have been presented. A new period of BZ Eri comes out to be 0d.6641703. The colour curves of the system show appreciable variations, and are indicative of intrinsic variability. The secondary minimum falls nearly at phase 0.5. Some interesting features are given. The features of BZ Eri are changing. Some light variations are visible around the phase of the secondary minimum. The discussion reveals that BZ Eri is a complicated system. 相似文献
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Vladimir Robert Matas 《Celestial Mechanics and Dynamical Astronomy》1982,27(1):23-25
Some additional remarks are made here concerning an exact proof of the applicability of Hill's equations in the linear-stability question in the elliptic restricted problem of three bodies. 相似文献
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Astrophysics - The prospects for astronomical observations in the ultraviolet (UV) are discussed in a brief review and the areas in which UV astronomy is especially in demand are listed. Some... 相似文献
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Spatially-homogeneous and anisotropic Bianchi type-I cosmological models are obtained, in Barber's second self-creation theory of gravitation, when the source of the gravitational field is a perfect fluid. Some physical and geometrical properties of the models are discussed. 相似文献
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The main parameters of spectroscopic experiments in the UV range of the electromagnetic spectrum are estimated. Different spectral devices are compared in terms of their potential quality. Some technical details of current UV experiments and prospects of spectrographs of the WSO-UV project are discussed. 相似文献