全文获取类型
收费全文 | 91篇 |
免费 | 0篇 |
专业分类
大气科学 | 2篇 |
地质学 | 4篇 |
海洋学 | 10篇 |
天文学 | 75篇 |
出版年
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2009年 | 3篇 |
2008年 | 2篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 3篇 |
2002年 | 4篇 |
2001年 | 7篇 |
2000年 | 2篇 |
1996年 | 3篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 4篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1972年 | 1篇 |
1971年 | 5篇 |
1970年 | 3篇 |
排序方式: 共有91条查询结果,搜索用时 15 毫秒
41.
É. A. Vitrichenko 《Astronomy Letters》2001,27(12):809-815
We analyze IUE spectra of the star 1016 Ori. Together with previously obtained visible spectra, they have allowed the wavelength range from 1150 to 7000 Å to be studied. Atmospheric parameters of the star were refined: logg=4.5(1), T eff=30000(1000) K, and ξt=15(5) km s?1. We measured the equivalent widths of ~500 lines and used them to compute the chemical composition. It turned out that the He, B, Mg, P, and S abundances were nearly solar; Ne, Ti, and Cr were overabundant; and C, N, O, Al, Si, Mn, Fe, Ni, and Zn were underabundant. 相似文献
42.
A. É. Rozenbush 《Astrophysics》1996,39(2):126-128
It is pointed out that dust formation in the principal shell of a nova in the equatorial belt only and the orientation of this belt relative to the line of sight may lead to an overestimation of the interstellar extinction and, consequently, to an overestimation of the luminosity of the nova. The orientation of the dust belt must also be taken into account in evaluating its contribution to the bolometric luminosity of the nova.Translated fromAstrofizika, Vol. 39, No. 2, pp. 237–241, April–June, 1996. 相似文献
43.
A. É. Rosenbush 《Astrophysics》2001,44(1):78-87
The behavior of profiles of the Na I D line and of the infrared Ca II triplet for the star R Coronae Borealis (R CrB) during shallow light minima of 1998-1999 is traced using high-resolution spectra. During a light maximum, the sodium lines had an absorption profile with a shift of —(2-4) km/sec. During a light minimum, a narrow emission feature, which has an almost constant absolute intensity and a shift of —(8-10) km/sec, and an intense circumstellar absorption feature, which has a variable profile and a variable relative shift corresponding to an increase to 220 km/sec in the velocity of mass ejection, appeared in the cores of absorption lines. For several days before the onset of a light minimum, all three calcium lines exhibited a narrow emission feature in the line core with a shift of —(1-5) km/sec. All the subsequent changes in a line involved mainly the shape of the absorption line profile. The narrow emission feature's absolute intensity and relative position were maintained during all our observations. The behavior of the Na I D line profiles can be described qualitatively within the framework of the model of a spherical dust shell. 相似文献
44.
45.
É. A. Vitrichenko 《Astrophysics》2008,51(3):424-426
The times of individual minima taken from the literature are used to plot the dependence of O-C on revolution number for the
eclipsing star BM Ori. A least squares fit of this plot yields the following photometric elements: Min I=JD2440265.331(5)+6.470524(3)·E.
__________
Translated from Astrofizika, Vol. 51, No. 3, pp. 501–503 (August 2008). 相似文献
46.
S. Robbe-Dubois S. Lagarde Y. Bresson R. G. Petrov M. Carbillet E. LeCoarer F. Rantakyrö I. Tallon-Bosc M. Vannier P. Antonelli G. Martinot-Lagarde A. Roussel D. Tasso 《Monthly notices of the Royal Astronomical Society》2009,395(2):991-1004
This paper presents a study of the atmospheric refraction and its effect on the light coupling efficiency in an instrument using single-mode optical fibres. We show the analytical approach which allowed us to assess the need to correct the refraction in J and H bands while observing with an 8-m Unit Telescope. We then developed numerical simulations to go further in calculations. The hypotheses on the instrumental characteristics are those of AMBER (Astronomical Multi BEam combineR), the near-infrared focal beam combiner of the Very Large Telescope Interferometric mode, but most of the conclusions can be generalized to other single-mode instruments. We used the software package caos to take into account the atmospheric turbulence effect after correction by the European Southern Observatory system Multi-Application Curvature Adaptive Optics. The optomechanical study and design of the system correcting the atmospheric refraction on AMBER is then detailed. We showed that the atmospheric refraction becomes predominant over the atmospheric turbulence for some zenith angles z and spectral conditions: for z larger than 30° in J band for example. The study of the optical system showed that it allows to achieve the required instrumental performance in terms of throughput in J and H bands. First observations in J band of a bright star, α Cir star, at more than 30° from zenith clearly showed the gain to control the atmospheric refraction in a single-mode instrument, and validated the operating law. 相似文献
47.
48.
49.
A. É. Nadzhip A. M. Tatarnikov V. I. Shenavrin G. Weigelt B. F. Yudin 《Astronomy Letters》2001,27(5):324-327
We present our JHKLM photometry for R Cas performed during 1988–2000. The pulsation period of R Cas is $P \approx 429\mathop .\limits^d 6$ , with the maximum IR brightness lagging behind the maximum visual brightness by ~0.2 P. The amplitude of light variations appreciably decreases with increasing wavelength at λ≤3 μm. At λ>3 μm, this decrease virtually ceases. There is a step on the ascending branch of IR JHK brightness. The K-L color index increases linearly with K magnitude: $K - L = 0.304K + 1\mathop .\limits^m 20$ . The color temperature dependence, T K-L =f(K), is also linear: T K?L = ?622K + 1100 K. In going from minimum to maximum, the K flux (as well as the bolometric flux) from the star and its color temperature T K-L increase by a factor of ~2.2 and ~1.3, respectively. 相似文献
50.