全文获取类型
收费全文 | 884篇 |
免费 | 10篇 |
国内免费 | 10篇 |
专业分类
测绘学 | 81篇 |
大气科学 | 9篇 |
地球物理 | 14篇 |
地质学 | 39篇 |
海洋学 | 2篇 |
天文学 | 750篇 |
综合类 | 5篇 |
自然地理 | 4篇 |
出版年
2023年 | 2篇 |
2022年 | 10篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 13篇 |
2018年 | 6篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 13篇 |
2014年 | 19篇 |
2013年 | 9篇 |
2012年 | 18篇 |
2011年 | 9篇 |
2010年 | 21篇 |
2009年 | 55篇 |
2008年 | 47篇 |
2007年 | 65篇 |
2006年 | 76篇 |
2005年 | 76篇 |
2004年 | 63篇 |
2003年 | 57篇 |
2002年 | 69篇 |
2001年 | 50篇 |
2000年 | 58篇 |
1999年 | 53篇 |
1998年 | 71篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 1篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1982年 | 3篇 |
1981年 | 1篇 |
排序方式: 共有904条查询结果,搜索用时 15 毫秒
111.
112.
Joanna P. Anosova 《Celestial Mechanics and Dynamical Astronomy》1991,51(1):1-15
Strong three-body interactions play a decisive role in the course of the dynamical evolution of triple systems having positive
as well as negative total energies. These interactions may produce qualitative changes in the relative motions of the components.
In triple systems with positive or zero total energies the processes of formation, disruption or exchange of the components
of binaries take place as the result of close approaches of the three single bodies or as the result of the passages of single
bodies past wide or hard binaries. In the triple systems with negative energies, the strong triple interactions may result
in an escape from the system as well as a formation of a hard final binary.
This paper summarizes the general results of the studies of the strong three-body interactions in the triple systems with
positive and negative energies. These studies were conducted at the Leningrad University Observatory by computer simulations
during 1968–1989. 相似文献
113.
Vacheslav Emel'yanenko 《Celestial Mechanics and Dynamical Astronomy》2002,84(4):331-341
A new symplectic algorithm is developed for cometary orbit integrations. The integrator can handle both high-eccentricity orbits and close encounters with planets. The method is based on time transformations for Hamiltonians separated into Keplerian and perturbation parts. The adaptive time-step of this algorithm depends on the distance from a centre and the magnitude of perturbations. The explicit leapfrog technique is simple and efficient. 相似文献
114.
115.
Three-color photoelectric UBV light curves of the close binary system V448 Cyg obtained at the Abastumani Astrophysical Observatory are analyzed using a new code by Djurasevi. A new value for the ratio of the masses of the components, which is the fundamental parameter for determining the absolute elements of the system, has recently been published. The parameters obtained in our analysis differ substantially from those published previously because the new mass ratio has been employed. The location of the components of V448 Cyg on a mass-logg plot shows that this system, similarly to XZ Cep and V382 Cyg, is in a phase subsequent to a rapid transfer of mass.Translated from Astrofizika, Vol. 48, No. 1, pp. 59–68 (February 2005). 相似文献
116.
117.
118.
Pasi Hakala Gavin Ramsay Panu Muhli Phil Charles Diana Hannikainen Koji Mukai Osmi Vilhu 《Monthly notices of the Royal Astronomical Society》2005,356(3):1133-1138
UW CrB (MS 1603+2600) is a peculiar short-period X-ray binary that exhibits extraordinary optical behaviour. The shape of the optical light curve of the system changes drastically from night to night, without any changes in overall brightness. Here we report X-ray observations of UW CrB obtained with XMM–Newton . We find evidence for several X-ray bursts, confirming a neutron star primary. This considerably strengthens the case that UW CrB is an accretion disc corona system located at a distance of at least 5–7 kpc (3–5 kpc above the Galactic plane). The X-ray and Optical Monitor (ultraviolet–optical) light curves show remarkable shape variation from one observing run to another, which we suggest are due to large-scale variations in the accretion disc shape resulting from a warp that periodically obscures the optical and soft X-ray emission. This is also supported by the changes in phase-resolved X-ray spectra. 相似文献
119.
Michał Siwak 《Astrophysics and Space Science》2005,296(1-4):289-292
In this paper we investigate a sample of contact eclipsing binary systems, which exhibit a large temperature difference (at
least 1000 K) between the components. Considering the effective temperature of the primary star, the systems were divided
into three groups. We applied a Monte Carlo method as a more suitable procedure for the search of the system configurations
previously known as contact binaries with a large temperature difference and with a negligible value of the filling factor.
Using only data presented in the literature, we found that the geometrical configuration of almost all systems from the second
group is near-contact rather than contact. 相似文献
120.