共查询到20条相似文献，搜索用时 745 毫秒
1.
S. R. Bourne 《Celestial Mechanics and Dynamical Astronomy》1972,6(2):167-186
This paper describes a method for finding literal expressions for the first order terms in the Moon's co-ordinates. The method is based on the use of rectangular co-ordinates and was originally proposed by Euler. The variation curve and the terms dependent on the first power of the Lunar eccentricity have been obtained. These results are compared with those of Hill and a number of errors in Hill's results have been found. 相似文献
2.
J.S. Boyd 《Planetary and Space Science》1977,25(4):411-414
Global maps of invariant geomagnetic co-ordinates calculated for epoch 1977.25 are presented. A more detailed report including computer programs for the rapid calculation of invariant co-ordinates is available. 相似文献
3.
J. Hpfner 《Astronomische Nachrichten》1980,301(1):27-32
The old programme of observations (cf. Beobachtungsergebnisse 1964 and Astronomische Zeit- und Breitenbestimmungen 1965, 1) was modified. The conditions described in Instruction (1956) were used again. As previously (cf. Beobachtungsergebnisse 1964), the stars were selected in respect of the derivation of corrections to the co-ordinates of the stars. The new programme, which has been in use since September of 1978, can be used up to the year 2000. 相似文献
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Recently we (Roy and Rana, 1990a) critically examined the self-consistency of the EIH equations of motion. A static spherically symmetric body as was pointed out there may not appear as a point mass with all its mass concentrated at its centre to a particle placed outside the body. An attempt to analyse this aspect further is made here in the context of the Chandrasekhar gauge. A comparison is also made with the general solutions obtained by Schwarzschild in the standard co-ordinates. Certain difficulties still exist. 相似文献
6.
This paper considers the possibility of using pulsed and continuous wave radio sources to scatter or reflect a signal from the ionisation produced by an Extensive Air Shower (EAS) to provide a precise indication of the source co-ordinates of the primary gamma ray. It indicates the limits of such methods and suggests a route which may result in a significant improvement in the current precision of cosmic gamma ray source coordinates. 相似文献
7.
美国国立光学天文台的IRAF软件系统,已成为国内光谱处理的主要计算机软件之一。由射电天文需要发展起来的FITS格式,已作为国际上交换磁带数据资料的通用格式。本文简单地介绍了FITS格式,讨论了如何将厚片CCD光谱观测资料转换为IRAF图像,继而转换为标准FITS格式。这对于使用IRAF系统进行光谱处理,以及国内国际间的资料交换是有用的。 相似文献
8.
LU Chunmei 《中国科学院上海天文台年刊》2003,(1)
由于磁带回放的不稳定性及磁带与处理机的不匹配 ,导致由磁带导入硬盘的数据误码率很高 ,影响了送入处理机的数据可用率。结果显示 ,采用核对软件能将数据可用率提高一个数量级 相似文献
9.
我国VLBI网包括上海佘山、乌鲁木齐和昆明 3个观测站 ,以及上海天文台研制的两台站相关处理机。上海佘山和乌鲁木齐站已升级成MK4制式和只使用薄磁带 ,而昆明站只能使用S2制式。因此 ,实现相关处理机对不同制式数据和薄磁带的兼容 ,是我国VLBI网顺利运行的关键。给出了多制式VLBI观测实验和相关处理的初步结果 ,总结了相关处理机升级后的处理能力 ,并对相关处理机的下一步发展作简单讨论 相似文献
10.
Computerized spherical harmonic analysis is applied to the morphology of the southern auroral oval. Records from 23 All Sky Camera stations together with visual observation reports for the period 1957–1959 constitute the raw data set. The mode of the derived auroral occurrence distribution function F(Kp, θ, φ) is regarded as the maximum probability contour and yields a set of auroral ovals. These 10 contours, one for each Kp level, are expressed in the invariant magnetic co-ordinates of Bond (1968). 相似文献
11.
Diarmuid O'Mathuna 《Celestial Mechanics and Dynamical Astronomy》1970,1(3-4):467-478
For Vinti's dynamical problem, there is proposed a new form of solution wherein all three coordinates are expressed in terms of one independent variable. The formulae for the three co-ordinates are clear generalizations of the corresponding formulae for the Kepler problem while the independent variable corresponds to the true anomaly. The solution is completed by the relation connecting the independent variable with time: the latter is a generalization of the well known Kepler time-angle relationship. From the form and method of solution the main qualitative features of the motion are readily derived. 相似文献
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H. Greiner-Mai 《Astronomische Nachrichten》1990,311(5):317-325
Non-axisymmetric motions of the outer core of the Earth are important for the dynamo problem and the excitation of the decade variations of the polar motion. The components of the vector of a rigid rotation of the outer core about an inclined axis were estimated by a first-order approximation of the frozen- field theory of the geomagnetic secular variation from 1903.5 to 1975.5. The trends and quasi-periodic constituents of these quantities were computed. It was shown that the position and time behaviour of the rotational pole of the outer core differ considerably from the well-know co-ordinates of the dipole axis. Some periods of the equatorial components of the rotational vector are comparable with those of the axial component previously derived for a pure axial rotation. Additionally, the time behaviour of the pole path shows events like the well-known Markowitz wobble but naturally with other extent. These and other results suggested that the investigations are worth to be continued in future by some physical interpretations. 相似文献
14.
Hawking’s radiation effect of Klein-Gordon scalar field, Dirac particles and Maxwell’s electromagnetic field in the non-stationary
rotating de Sitter cosmological space-time is investigated by using a method of generalized tortoise co-ordinates transformation.
The locations and the temperatures of the cosmological horizons of the non-stationary rotating de Sitter model are derived.
It is found that the locations and the temperatures of the rotating cosmological model depend not only on the time but also
on the angle. The stress-energy regularization techniques are applied to the two dimensional analog of the de Sitter metrics
and the calculated stress-energy tensor contains the thermal radiation effect. 相似文献
15.
The Machinga meteorite fell in the Southern Province of Malawi on January 22, 1981, at approximately 1000 hours local time. The fall site is about 7.5 km SW of Machinga and has the co-ordinates 15° 12′44″ S., 35°14′32″ E. A single crusted mass weighing 93.2 kg was recovered. The Machinga meteorite is an L6 chondrite with olivine Fa24.5 and orthopyroxene Fs21.1. The silicates have a granular texture and the stone has been shocked. 相似文献
16.
In FRW space time Brans-Dicke theory is developed for two cases: (i) the vacuum and (ii) the perfect fluid model. The field equations are transformed into a much simpler form under a change of time co-ordinates and then the solutions are determined for the above cases. An equation of statep =/3 (radiation) is assumed in the case of perfect fluid. 相似文献
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Brian L. Smith 《Astrophysics and Space Science》1976,43(2):411-424
It was shown in a previous paper, Smith (1975), that the determination of the structure of rotating polytropes by expansion in the small rotational parameter constitutes asingular perturbation problem as arises also, for example, in large Reynolds' number approximations in fluid dynamics. The technique used by him — the method of matched asymptotic expansions — is, in fact, just an extension of the Prandtl boundary layer theory familiar in this latter context. In this paper — the first of two — we introduce an alternative procedure: the method of strained co-ordinates; and for comparison purposes again consider rotating polytropes. In Paper II we extend this approach to differentially rotating stars and present an illustrative example. 相似文献
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A. R. Whitney 《New Astronomy Reviews》1999,43(8-10)
Magnetic tape recording, disc recording, and global electronic networks are advancing rapidly, promising both evolutionary and revolutionary impacts on the way VLBI is conducted. In this paper, we will examine the state-of-the-art technologies that may have application to VLBI and consider the current and projected costs in each of these areas. 相似文献