全文获取类型
| 收费全文 | 310篇 |
| 免费 | 7篇 |
专业分类
| 测绘学 | 6篇 |
| 大气科学 | 23篇 |
| 地球物理 | 161篇 |
| 地质学 | 71篇 |
| 海洋学 | 3篇 |
| 天文学 | 30篇 |
| 综合类 | 1篇 |
| 自然地理 | 22篇 |
出版年
| 2019年 | 3篇 |
| 2018年 | 3篇 |
| 2017年 | 4篇 |
| 2016年 | 9篇 |
| 2015年 | 10篇 |
| 2014年 | 13篇 |
| 2013年 | 11篇 |
| 2012年 | 10篇 |
| 2011年 | 13篇 |
| 2010年 | 11篇 |
| 2009年 | 13篇 |
| 2008年 | 7篇 |
| 2007年 | 8篇 |
| 2005年 | 3篇 |
| 2004年 | 5篇 |
| 2003年 | 6篇 |
| 2002年 | 3篇 |
| 2001年 | 8篇 |
| 2000年 | 12篇 |
| 1999年 | 5篇 |
| 1998年 | 3篇 |
| 1997年 | 8篇 |
| 1996年 | 3篇 |
| 1993年 | 5篇 |
| 1992年 | 7篇 |
| 1990年 | 5篇 |
| 1989年 | 3篇 |
| 1987年 | 4篇 |
| 1983年 | 4篇 |
| 1982年 | 3篇 |
| 1981年 | 4篇 |
| 1980年 | 6篇 |
| 1979年 | 4篇 |
| 1977年 | 3篇 |
| 1976年 | 4篇 |
| 1975年 | 4篇 |
| 1971年 | 4篇 |
| 1970年 | 6篇 |
| 1969年 | 3篇 |
| 1968年 | 6篇 |
| 1967年 | 3篇 |
| 1966年 | 5篇 |
| 1965年 | 3篇 |
| 1963年 | 3篇 |
| 1960年 | 4篇 |
| 1959年 | 6篇 |
| 1958年 | 5篇 |
| 1957年 | 3篇 |
| 1954年 | 3篇 |
| 1948年 | 2篇 |
排序方式： 共有317条查询结果，搜索用时 15 毫秒
81.
82.
83.
84.
85.
86.
Fabian Josef Winterberg Efi Meletlidou 《Celestial Mechanics and Dynamical Astronomy》2004,88(4):415-420
Volume Contents
Celestial Mechanics and Dynamical Astronomy 相似文献87.
Mean tendencies and variances of ad hoc mean estimates (field estimates) of some engineering geological parameters were compared to statistically obtained reference values. The latter correspond to the “best” estimates in the sense of approximating so-called reality (Einstein and Baecher, 1982. Probabilistic and statistical methods in engineering geology. Problem statement and introduction to solution. Rock Mech., Suppl. 12: 47–61; Einstein and Baecher, 1983. Probabilistic and statistical methods in engineering geology. Specific methods and examples, Part I: Exploration. Rock Mech. Rock Eng., 16: 39–72). The study was carried out by means of a demoscopic field study on 43 engineering geologists. “Professional experience” was examined by comparing the estimation results of two trial groups, one consisting of people with several years of professional experience, the other one consisting of university students. The biases of the ad hoc estimates due to subjectivity and the limitation of working time at the selected reference outcrops follow statistically describable trends and thus can be analyzed by univariate and multivariate methods. Some geological and psychological hypotheses concerning the mean estimation trends, correlations and discriminations are postulated. Implications on commonly used field estimation methods are discussed. 相似文献
88.
Josef Kallrath Johannes P. Schlöder Hans Georg Bock 《Celestial Mechanics and Dynamical Astronomy》1993,56(1-2):353-371
A recent least squares algorithm, which is designed to adapt implicit models to given sets of data, especially models given by differential equations or dynamical systems, is reviewed and used to fit the Hénon-Heiles differential equations to chaotic data sets.This numerical approach for estimating parameters in differential equation models, called theboundary value problem approach, is based on discretizing the differential equations like a boundary value problem,e.g. by a multiple shooting or collocation method, and solving the resulting constrained least squares problem with a structure exploiting generalized Gauss-Newton-Method (Bock, 1981).Dynamical systems like the Hénon-Heiles system which can have initial values and parameters that lead to positive Lyapunov exponents or phase space filling Poincaré maps give rise to chaotic time series. Various scenarios representing ideal and noisy data generated from the Hénon-Heiles system in the chaotic region are analyzedw.r.t. initial conditions, parameters and Lyapunov exponents. The original initial conditions and parameters are recovered with a given accuracy. The Lyapunov spectrum is then computed directly from the identified differential equations and compared to the spectrum of the true dynamics.presently at IWR, Universität Heidelberg, Im Neuenheimer Feld 368, D-6900 Heidelberg, Germany 相似文献
89.
90.