全文获取类型
收费全文 | 723611篇 |
免费 | 6331篇 |
国内免费 | 2066篇 |
专业分类
化学 | 365511篇 |
晶体学 | 10678篇 |
力学 | 36166篇 |
综合类 | 20篇 |
数学 | 96431篇 |
物理学 | 223202篇 |
出版年
2021年 | 6533篇 |
2020年 | 7008篇 |
2019年 | 7915篇 |
2018年 | 10609篇 |
2017年 | 10876篇 |
2016年 | 15141篇 |
2015年 | 8545篇 |
2014年 | 14184篇 |
2013年 | 33116篇 |
2012年 | 25478篇 |
2011年 | 30462篇 |
2010年 | 22591篇 |
2009年 | 22537篇 |
2008年 | 28417篇 |
2007年 | 28103篇 |
2006年 | 25760篇 |
2005年 | 22945篇 |
2004年 | 21301篇 |
2003年 | 19109篇 |
2002年 | 18979篇 |
2001年 | 20983篇 |
2000年 | 16021篇 |
1999年 | 12482篇 |
1998年 | 10637篇 |
1997年 | 10404篇 |
1996年 | 9744篇 |
1995年 | 8705篇 |
1994年 | 8651篇 |
1993年 | 8345篇 |
1992年 | 8954篇 |
1991年 | 9500篇 |
1990年 | 9063篇 |
1989年 | 8934篇 |
1988年 | 8553篇 |
1987年 | 8509篇 |
1986年 | 8117篇 |
1985年 | 10362篇 |
1984年 | 10784篇 |
1983年 | 9021篇 |
1982年 | 9310篇 |
1981年 | 8734篇 |
1980年 | 8425篇 |
1979年 | 9038篇 |
1978年 | 9276篇 |
1977年 | 9115篇 |
1976年 | 9041篇 |
1975年 | 8675篇 |
1974年 | 8511篇 |
1973年 | 8808篇 |
1972年 | 6321篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
S. B. Kuksin 《Proceedings of the Steklov Institute of Mathematics》2007,259(1):128-136
We discuss the inviscid limits for the randomly forced 2D Navier-Stokes equation (NSE) and the damped/driven KdV equation.
The former describes the space-periodic 2D turbulence in terms of a special class of solutions for the free Euler equation,
and we view the latter as its model. We review and revise recent results on the inviscid limit for the perturbed KdV and use
them to suggest a setup which could be used to make a next step in the study of the inviscid limit of 2D NSE. The proposed
approach is based on an ergodic hypothesis for the flow of the 2D Euler equation on iso-integral surfaces. It invokes a Whitham
equation for the 2D Navier-Stokes equation, written in terms of the ergodic measures. 相似文献
993.
The structure of a spin spiral arising in the vicinity of the interface between a ferromagnet and a compensated antiferromagnet is studied in the case where the anisotropy axes of the layers are parallel to each other, and the evolution of this spiral in an external magnetic field is investigated. 相似文献
994.
E. A. Nelin 《Technical Physics》2007,52(9):1222-1224
A method of producing narrowband high-selectivity filters based on resonance tunneling in onebarrier crystallike structures is proposed. Characteristics illustrating the efficiency of the method are presented. 相似文献
995.
S. V. Tolstousov A. A. Grekov A. S. Tolstousov 《Bulletin of the Russian Academy of Sciences: Physics》2007,71(5):721-723
A model of a capacitor with a two-layer insulator has been considered. The current density exponentially depends on voltage in one of layers and is negligible in the other layer. The dependences of current on the time of voltage action and the charge-voltage characteristics of the two-layer capacitor have been calculated. The results obtained can be used to detect and study charge injection during polarization of ferroelectrics. 相似文献
996.
A. I. Khil’ko A. G. Luchinin V. G. Burdukovskaya I. P. Smirnov 《Acoustical Physics》2007,53(3):381-392
Potentialities of observing spatially localized inhomogeneities by the low-frequency low-mode pulsed diffraction tomography in a shallow sea are analyzed. A numerically simulated model is used to study the procedure of reconstructing the parameters of inhomogeneities by coprocessing the signals of the tomographic projections formed at the multistatic excitation and reception of low-frequency low-mode acoustic pulses. 相似文献
997.
998.
M. L. Eritsyan L. A. Gyurdzhyan L. T. Melkonyan G. V. Akopyan 《Russian Journal of Applied Chemistry》2006,79(10):1666-1668
Composition and rheological characteristics of aqueous solutions of acrylic acid/urea copolymers were studied, including the composition dependences of the equivalent conductivity and viscosity. 相似文献
999.
A. V. Boldashevskii Zh. K. Tukhmetova Sh. B. Kasenova S. M. Adekenov A. Nukhuly B. K. Kasenov A. M. Gazaliev S. D. Fazylov 《Russian Journal of Applied Chemistry》2006,79(10):1705-1708
Results of thermochemical studies of a new compound, potassium morpholinodithiocarbamate, are presented. The enthalpies of its solution in water at various dilutions and the specific heat at 173–348 K were examined by the experimental methods of isothermal and dynamic calorimetry. 相似文献
1000.
We introduce a family of matrices that define logics in which paraconsistency and/or paracompleteness occurs only at the level of literals, that is, formulas that are propositional letters or their iterated negations. We give a sound and complete axiomatization for the logic defined by the class of all these matrices, we give conditions for the maximality of these logics and we study in detail several relevant examples. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献