全文获取类型
收费全文 | 1200篇 |
免费 | 17篇 |
国内免费 | 8篇 |
专业分类
化学 | 787篇 |
晶体学 | 5篇 |
力学 | 11篇 |
数学 | 235篇 |
物理学 | 187篇 |
出版年
2021年 | 11篇 |
2020年 | 9篇 |
2019年 | 13篇 |
2018年 | 11篇 |
2017年 | 11篇 |
2016年 | 22篇 |
2015年 | 24篇 |
2014年 | 24篇 |
2013年 | 44篇 |
2012年 | 53篇 |
2011年 | 52篇 |
2010年 | 38篇 |
2009年 | 32篇 |
2008年 | 61篇 |
2007年 | 65篇 |
2006年 | 60篇 |
2005年 | 46篇 |
2004年 | 38篇 |
2003年 | 33篇 |
2002年 | 43篇 |
2001年 | 10篇 |
1999年 | 8篇 |
1998年 | 10篇 |
1996年 | 12篇 |
1994年 | 7篇 |
1993年 | 7篇 |
1992年 | 8篇 |
1991年 | 16篇 |
1989年 | 7篇 |
1985年 | 11篇 |
1983年 | 7篇 |
1982年 | 8篇 |
1981年 | 12篇 |
1979年 | 10篇 |
1978年 | 10篇 |
1977年 | 8篇 |
1975年 | 7篇 |
1974年 | 8篇 |
1935年 | 7篇 |
1927年 | 9篇 |
1926年 | 7篇 |
1913年 | 7篇 |
1912年 | 11篇 |
1911年 | 7篇 |
1910年 | 9篇 |
1909年 | 19篇 |
1903年 | 8篇 |
1898年 | 7篇 |
1890年 | 8篇 |
1885年 | 11篇 |
排序方式: 共有1225条查询结果,搜索用时 218 毫秒
171.
Emil Jebek 《Mathematical Logic Quarterly》2004,50(3):295-296
Grzegorczyk's modal logic (Grz) corresponds to the class of upwards well‐founded partially ordered Kripke frames, however all known proofs of this fact utilize some form of the Axiom of Choice; G. Boolos asked in [1], whether it is provable in plain ZF. We answer his question negatively: Grz corresponds (in ZF) to a class of frames, which does not provably coincide with upwards well‐founded posets in ZF alone. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
172.
Xavier Balandraud Emil Ernst Eugen Soós 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2005,56(2):304-356
To describe the behavior of Shape Memory Alloy we use a thermomechanical model, founded on a free energy which is a convex function with respect to the strain and to the martensitic volume fraction, and a concave one with respect to the temperature. The material parameters of the model are experimentally determined.Received: November 26, 2001; revised: March 20, 2002 相似文献
173.
M. B. Sapadinsky L. Tschugajeff L. Rosen F. Penzoldt und Emil Fischer 《Fresenius' Journal of Analytical Chemistry》1928,74(8):273-275
Ohne Zusammenfassung 相似文献
174.
Forman's discrete Morse theory is studied from an algebraic viewpoint, and we show how this theory can be extended to chain complexes of modules over arbitrary rings. As applications we compute the homologies of a certain family of nilpotent Lie algebras, and show how the algebraic Morse theory can be used to derive the classical Anick resolution as well as a new two-sided Anick resolution.
175.
Oscillation of solutions of impulsive nonlinear parabolic differential-difference equations 总被引:6,自引:0,他引:6
Sufficient conditions for oscillation of the solutions of impulsive nonlinear parabolic differential-difference equations are obtained. 相似文献
176.
The recent generalized gradient approximation (GGA) density functional OCS1 of Handy and Cohen is implemented in the deMon code and tested on a carefully selected set of problems. OCS1 is found to be accurate for molecular atomization energies, transition metal–ligand bonds, and systems with intramolecular hydrogen bonds. However, OCS1 encounters problems for systems with intermolecular hydrogen bonds. It also tends to elongate bond lengths systematically, and sometimes significantly. The OPTX exchange is combined with three meta‐GGA correlation functionals, Lap3, τ1, and τ2, the latter reported for the first time. The new meta‐GGA scheme OPTX exchange plus τ2 correlation called Oτ2 yields improved molecular geometries, NMR shielding constants, and an improved barrier height for the H+H2 reaction. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006 相似文献
177.
Emil Waelsch 《Monatshefte für Mathematik》1906,17(1):241-280
Ohne Zusammenfassung 相似文献
178.
Ohne ZusammenfassungHerrn A. Landsiedl, der uns bei dieser Arbeit unterstützte, sagen wir den besten Dank. 相似文献
179.
180.
Gregory R. Carmichael Adrian Sandu Tianfeng Chai Dacian N. Daescu Emil M. Constantinescu Youhua Tang 《Journal of computational physics》2008,227(7):3540-3571
Air quality prediction plays an important role in the management of our environment. Computational power and efficiencies have advanced to the point where chemical transport models can predict pollution in an urban air shed with spatial resolution less than a kilometer, and cover the globe with a horizontal resolution of less than 50 km. Predicting air quality remains a challenge due to the complexity of the governing processes and the strong coupling across scales. While air quality prediction is closely aligned with weather prediction, there are important differences, including the role of pollution emissions and their associated large uncertainties. Improvements in air quality prediction require a close integration of observations. As more atmospheric chemical observations become available chemical data assimilation is expected to play an essential role in air quality forecasting. In this paper advances in air quality forecasting are discussed with an emphasis on data assimilation. Applications of the four-dimensional variational method (4D-Var) and the ensemble Kalman filter (EnKF) approach are presented and the computation challenges are discussed. 相似文献