全文获取类型
收费全文 | 267260篇 |
免费 | 1867篇 |
国内免费 | 525篇 |
专业分类
化学 | 120511篇 |
晶体学 | 3657篇 |
力学 | 14001篇 |
综合类 | 3篇 |
数学 | 43720篇 |
物理学 | 87760篇 |
出版年
2020年 | 1432篇 |
2019年 | 1570篇 |
2018年 | 10684篇 |
2017年 | 11589篇 |
2016年 | 7200篇 |
2015年 | 2778篇 |
2014年 | 3255篇 |
2013年 | 7811篇 |
2012年 | 10014篇 |
2011年 | 19134篇 |
2010年 | 12085篇 |
2009年 | 12138篇 |
2008年 | 16968篇 |
2007年 | 20383篇 |
2006年 | 6315篇 |
2005年 | 12110篇 |
2004年 | 8474篇 |
2003年 | 7969篇 |
2002年 | 5858篇 |
2001年 | 5414篇 |
2000年 | 4205篇 |
1999年 | 3041篇 |
1998年 | 2546篇 |
1997年 | 2395篇 |
1996年 | 2240篇 |
1995年 | 2182篇 |
1994年 | 2175篇 |
1993年 | 2052篇 |
1992年 | 2327篇 |
1991年 | 2268篇 |
1990年 | 2223篇 |
1989年 | 2154篇 |
1988年 | 2180篇 |
1987年 | 2182篇 |
1986年 | 2068篇 |
1985年 | 2703篇 |
1984年 | 2764篇 |
1983年 | 2430篇 |
1982年 | 2555篇 |
1981年 | 2360篇 |
1980年 | 2352篇 |
1979年 | 2528篇 |
1978年 | 2567篇 |
1977年 | 2419篇 |
1976年 | 2527篇 |
1975年 | 2412篇 |
1974年 | 2377篇 |
1973年 | 2590篇 |
1972年 | 1655篇 |
1971年 | 1350篇 |
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
991.
A. M. Povolotsky V. B. Priezzhev Chin-Kun Hu 《Journal of statistical physics》2003,111(5-6):1149-1182
An asymmetric stochastic process describing the avalanche dynamics on a ring is proposed. A general kinetic equation which incorporates the exclusion and avalanche processes is considered. The Bethe ansatz method is used to calculate the generating function for the total distance covered by all particles. It gives the average velocity of particles which exhibits a phase transition from an intermittent to continuous flow. We calculated also higher cumulants and the large deviation function for the particle flow. The latter has the universal form obtained earlier for the asymmetric exclusion process and conjectured to be common for all models of the Kardar–Parisi–Zhang universality class. 相似文献
992.
Harper equations are derived for a px, py electronic system. Analysis is carried out for extreme points of the quasi-continuous spectrum in the cases when the number of magnetic flux quanta through a unit cell is a rational number and calculations are made for square and triangular lattices as well as for a honeycomb lattice with two nonequivalent atoms. The possibility of application of the results for explaining the fractional Hall effect is considered. 相似文献
993.
994.
V. P. Shilov 《Journal of Experimental and Theoretical Physics》2003,96(4):719-729
The supercritical Marangoni convection has been studied in a plane-parallel liquid layer, bounded by a free deformable gas-liquid interface from above and by a low-heat-conductivity wall from below, occurring under conditions of inhomogeneous heating in the horizontal plane. In a longwave approximation with a small inhomogeneity of heat flux, the process is described by a system of two-dimensional nonlinear equations for the temperature perturbations, vorticity, and free surface deformation. The concept of quasiequilibrium, implying stability of long-range flows, is introduced, which allows the inhomogeneous heat flux to be modeled by a step function. The linear stability is analyzed in the cases of planar and axisymmetric heat fluxes. The boundaries of stability of the convection regimes are determined on the plane of parameters characterizing the degree of supercriticity inside a heated spot and the depth of damping outside the spot. For an axisymmetric spot, the domains of stability with respect to perturbations for various azimuthal numbers are established. 相似文献
995.
996.
The logarithmic decrement and shear modulus of a bulk amorphous Zr52.5Ti5Cu17.9Ni14.6Al10 alloy were studied with an inverse torsion pendulum in the range from room temperature to the crystallization temperature and in the frequency range 5–40 Hz. The activation energy spectra of reversible and irreversible structural relaxation were estimated. The results obtained are discussed in the context of a two-energy-level model. 相似文献
997.
998.
V. A. Reznikov 《Technical Physics》2003,48(9):1216-1218
A shell model that describes the formation of molecular complexes around a C60 molecule upon the solid-phase interaction of the powders is considered. From the absorption spectra, it follows that a reacting
particle is a fullerene dimer. 相似文献
999.
T. M. Shneidman G. G. Adamian N. V. Antonenko S. P. Ivanova R. V. Jolos W. Scheid 《Physics of Atomic Nuclei》2003,66(2):206-217
Based on the dinuclear system concept, the role of bending vibrations in creation of the angular momentum of primary fission fragments is investigated. For 252Cf spontaneous fission, the angular momenta of the fragments are calculated as a function of the neutron multiplicity and compared with available experimental data. Different cluster compositions of the 252Cf fission modes at the scission point are considered. 相似文献
1000.
R. Weidmann 《Archiv der Mathematik》2003,81(5):589-595
We describe a family of graph manifolds that have 2-generated
fundamental group but do not admit a Heegaard splitting of genus 2. They are
closely related to the examples provided by Boileau and Zieschang if these are
considered as (non-proper) graph manifolds.Received: 14 August 2002 相似文献