全文获取类型
收费全文 | 169772篇 |
免费 | 7416篇 |
国内免费 | 10584篇 |
专业分类
化学 | 26929篇 |
晶体学 | 292篇 |
力学 | 6928篇 |
综合类 | 1328篇 |
数学 | 34580篇 |
物理学 | 22567篇 |
综合类 | 95148篇 |
出版年
2024年 | 251篇 |
2023年 | 1076篇 |
2022年 | 1772篇 |
2021年 | 1998篇 |
2020年 | 2231篇 |
2019年 | 2492篇 |
2018年 | 2201篇 |
2017年 | 2577篇 |
2016年 | 2861篇 |
2015年 | 3426篇 |
2014年 | 6217篇 |
2013年 | 7768篇 |
2012年 | 7683篇 |
2011年 | 8701篇 |
2010年 | 7436篇 |
2009年 | 9141篇 |
2008年 | 9930篇 |
2007年 | 11709篇 |
2006年 | 11195篇 |
2005年 | 10446篇 |
2004年 | 8844篇 |
2003年 | 8528篇 |
2002年 | 7453篇 |
2001年 | 6326篇 |
2000年 | 5757篇 |
1999年 | 4938篇 |
1998年 | 4224篇 |
1997年 | 3784篇 |
1996年 | 3407篇 |
1995年 | 3070篇 |
1994年 | 2900篇 |
1993年 | 2503篇 |
1992年 | 2334篇 |
1991年 | 2060篇 |
1990年 | 1817篇 |
1989年 | 1742篇 |
1988年 | 1478篇 |
1987年 | 939篇 |
1986年 | 665篇 |
1985年 | 552篇 |
1984年 | 487篇 |
1983年 | 222篇 |
1982年 | 377篇 |
1981年 | 434篇 |
1980年 | 345篇 |
1979年 | 321篇 |
1978年 | 248篇 |
1977年 | 243篇 |
1976年 | 178篇 |
1974年 | 124篇 |
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
991.
Constants of Motion for Several One-Dimensional Systems and Problems Associated with Getting Their Hamiltonians 总被引:1,自引:1,他引:0
G. López L. A. Barrera Y. Garibo H. Hernández J. C. Salazar C. A. Vargas 《International Journal of Theoretical Physics》2004,43(10):2009-2021
The constants of motion of the following systems are deduced: a relativistic particle with linear dissipation; a no-relativistic particle with a time explicitly depending force; a no-relativistic particle with a constant force and time depending mass; and a relativistic particle under a conservative force with position depending mass. The Hamiltonian for these systems, which is determined by getting the velocity as a function of position and generalized linear momentum, can be found explicitly at first approximation for the first system. The Hamiltonians for the other systems are kept implicitly in their expressions for their constants of motion. 相似文献
992.
Summary The detachment of a rubber matrix from a rigid inclusion under monotonic loading and at subsequent relaxation is investigated within two dimensional analysis. Examined are stress–strain experimental data acquired with the help of a test bed equipped with a digital image-acquisition device. The influence of the interfacial bonding strength and the particle size on the detachment process is analyzed. The influence of the interfacial bonding strength is visible in the stress–strain diagram of loading and in the recorded images. The relaxation test reveals no influence of the bonding strength on the stress-relaxation. However, the image analysis indicates a secondary transient creep of the contour of detachment, which depends on the interfacial bonding. 相似文献
993.
Ya.G. Groda P. Argyrakis G.S. Bokun V.S. Vikhrenko 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,32(4):527-535
The selfconsistent diagram approximation (SCDA) is generalized for three-dimensional lattice gases with nearest neighbor repulsive
interactions. The free energy is represented in a closed form through elementary functions. Thermodynamical (phase diagrams,
chemical potential and mean square fluctuations), structural (order parameter, distribution functions) as well as diffusional
characteristics are investigated. The calculation results are compared with the Monte Carlo simulation data to demonstrate
high precision of the SCDA in reproducing the equilibrium lattice gas characteristics. It is shown that similarly to two-dimensional
systems the specific statistical memory effects strongly influence the lattice gas diffusion in the ordered states.
Received 7 August 2002 / Received in final form 22 January 2003 Published online 24 April 2003 相似文献
994.
无界区域R1上推广的B-BBM方程的整体吸引子 总被引:4,自引:0,他引:4
本文研究了无界区域R^1上推广的B—BBM方程的长时间动力学行为,证明了该方程整体吸引子的存在性. 相似文献
995.
综述了暗中空光束自旋与轨道角动量的一些性质及其与中性原子之间的相互作用,并简单介绍了暗中空光束及其角动量在原子光学和玻色_爱因斯坦凝聚(BEC)以及各种原子光学器件研制方面的应用. 相似文献
996.
997.
We use methods of nonequilibrium statistical thermodynamics to investigate two dissipative processes in solids. We find the electron energy losses of a particle moving in a planar channeling regime and the sound absorption coefficient in metals under electron impurity scattering. The oscillator model is used to analyze the contribution from the effect of electron entrainment by a moving scattering center to the total dissipated energy. We investigate the frequency and temperature dependence of energy losses and also the dependence of the absorption coefficient on the sound wave vector. 相似文献
998.
We show that Poisson integrals belonging to certain weighted harmonic Bergman spaces bδp on the upper half-space must have the moment vanishing properties. As an application, we show that b0p, p?1, contains a dense subspace whose members have the horizontal moment vanishing properties. Also, we derive related weighted norm inequalities for Poisson integrals. As a consequence, we obtain a characterization for Poisson integrals of continuous functions with compact support in order to belong to bδp. 相似文献
999.
Shy-Der Lin 《Journal of Mathematical Analysis and Applications》2004,294(2):399-411
The main object of this paper is to investigate several general families of hypergeometric polynomials and their associated single-, double-, and triple-integral representations. Some known or new consequences of the general results presented here, involving such classical orthogonal polynomials as the Jacobi, Laguerre, Hermite, and Bessel polynomials, and various other relatively less familiar hypergeometric polynomials, are also considered. Each of the integral representations, which are derived in this paper, may be viewed also as a linearization relationship for the product of two different members of the associated family of hypergeometric polynomials. 相似文献
1000.
Naoki Murabayashi 《Journal of Number Theory》2004,108(2):268-286
The purpose of this paper is to decide the conditions under which a CM elliptic curve is modular over its field of definition. 相似文献