全文获取类型
收费全文 | 233篇 |
免费 | 4篇 |
国内免费 | 5篇 |
专业分类
测绘学 | 2篇 |
大气科学 | 3篇 |
地球物理 | 33篇 |
地质学 | 114篇 |
海洋学 | 8篇 |
天文学 | 77篇 |
自然地理 | 5篇 |
出版年
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 18篇 |
2017年 | 11篇 |
2016年 | 13篇 |
2015年 | 6篇 |
2014年 | 9篇 |
2013年 | 14篇 |
2012年 | 9篇 |
2011年 | 12篇 |
2010年 | 4篇 |
2009年 | 10篇 |
2008年 | 10篇 |
2007年 | 8篇 |
2006年 | 4篇 |
2005年 | 8篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1992年 | 7篇 |
1991年 | 1篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 7篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1977年 | 1篇 |
1969年 | 1篇 |
1917年 | 1篇 |
1907年 | 1篇 |
排序方式: 共有242条查询结果,搜索用时 15 毫秒
101.
Osman Demircan 《Astrophysics and Space Science》1987,136(1):201-205
The rotation period-activity luminosity and the rotation period-surface activity flux correlations for the components of RS CVn-type binaries are discussed. It is argued that such correlations, although they are required by dynamo generated magnetic fields, do not represent the dominant parameter in determining the level of activity. Evidences are given that these correlations may essentially be induced by the period-radius dependence for the components of RS CVn-type binaries, and in addition, this result may well be valid for all the late-type stars (single or binary components). 相似文献
102.
In this part we find out the 24 equations of secular perturbation equations for the subsystem J-S-U-N. The solution of these equations by the Lagrange-Laplace procedure and the Eigen value Eigen vector is analysed. Also we refer to Hurwitz theorem to test stability. 相似文献
103.
Osman M. Kamel 《Earth, Moon, and Planets》1982,26(1):47-60
We review in this part the outline of a third-order general planetary theory established through Von Zeipel's method and in terms of Poincaré's canonical variables We consider our system to consist of the Sun as the primary body, one disturbed planet, and one disturbing planet. 相似文献
104.
Osman M. Kamel 《Earth, Moon, and Planets》1988,43(3):271-273
A method to calculate secular terms of the two parts of the planetary disturbing function— when it is expressed in terms of the true anomalies or the eccentric anomalies instead of the mean anomalies - is described. Also an alternative method is outlined. 相似文献
105.
Osman Demircan 《Astrophysics and Space Science》1978,56(2):389-401
A new general expression for the theoretical momentsA
2m of the light curves of eclipsing systems has been presented in the form of infinite series expansion. In this expansion, the terms have been given as the product of two different polynomials which satisfy certain three-term recursion formulae, and the coefficients diminish rapidly with increasing number of terms. Thus, the numerical values of the theoretical momentsA
2m can be generated recursively up to four significant figures for any given set of eclipse elements. This can be utilized to solve the eclipse elements in two ways: (i) with an indirect method (for the procedures see Paper XIV, Kopal and Demircan, 1978), (ii) with a direct method as minimization to the observational momentsA
2m (area fitting). The procedures given in Paper XIV for obtaining the elements of any eclipsing system consisting of spherical stars have been automated by making use of the new expression for the momentsA
2m of the light curves. The theoretical functionsf
0,f
2,f
4,f
6,g
2 andg
4 which are the functions ofa andc
0, have been used to solve the eclipse elements from the observed photometric data. The closed-form expressions for the functionsf
2,f
4 andf
6 have also been derived (Section 3) in terms of Kopal'sI-integrals.The automated methods for obtaining the eclipse elements from one minimum alone have been tested on the light curves of YZ (21) Cassiopeiae under the spherical model assumptions. The results of these applications will be given in Section 5 which follows a brief introduction to the procedure we followed. 相似文献
106.
Osman M. Kamel 《Earth, Moon, and Planets》1996,74(1):1-6
We present a literal approach to evaluate –s
necessary for the construction of high order planetary theories. This approach is valid to be applied on very large scale digital computers with standard Poisson series programs, for high order and high degree planetary theories. We apply the method of symbolic differential operators for single variable functions, and the binomial theorem expansions, for the evaluation of –s
. We utilize Laplace coefficients and its derivatives to carry out the development, without dealing with Newcomb operators or Hansen's coefficients. 相似文献
107.
A solution of the Uranus-Neptune planetary canonical equations of motion through the Von Zeipel technique is presented. A unique determinging function which depends upon mixed canonical variables, reduces the 12 critical terms of the Hamiltonian to the set of its secular terms. The Poincaré canonical variables are used. We refer to a common fixed plane, and apply the Jacobi-Radau set of origins. In our expansion we neglected terms of power higher than the fourth with respect to the eccentricities and sines of the inclinations. 相似文献
108.
In this part we obtain the expression for –s
by the application of Smart's method, which involves Taylor's theorem for functions of several variables. We neglected terms of power higher than the fourth with respect to eccentricities and tangents of inclinations. 相似文献
109.
Osman M. Kamel 《Earth, Moon, and Planets》1982,27(4):407-415
An outline for the elimination of the critical terms of a first order Uranus-Neptune theory is presented with a stress on the application of Hori's procedure to the problem. 相似文献
110.
Osman M. Kamel 《Astrophysics and Space Science》1979,64(1):227-238
We construct a first-order secular general planetary theory, using the Jacobi-Radau set of origins, referring to common fixed plane and in terms of Poincaré canonical variables. We neglect powers higher than the fourth with respect to the eccentricities and sines of inclinations. 相似文献