全文获取类型
收费全文 | 31665篇 |
免费 | 4381篇 |
国内免费 | 2366篇 |
专业分类
化学 | 5617篇 |
晶体学 | 185篇 |
力学 | 5346篇 |
综合类 | 523篇 |
数学 | 12064篇 |
物理学 | 14677篇 |
出版年
2024年 | 71篇 |
2023年 | 327篇 |
2022年 | 906篇 |
2021年 | 859篇 |
2020年 | 1019篇 |
2019年 | 899篇 |
2018年 | 836篇 |
2017年 | 1122篇 |
2016年 | 1300篇 |
2015年 | 972篇 |
2014年 | 1657篇 |
2013年 | 2456篇 |
2012年 | 1698篇 |
2011年 | 2009篇 |
2010年 | 1755篇 |
2009年 | 2095篇 |
2008年 | 1951篇 |
2007年 | 1965篇 |
2006年 | 1667篇 |
2005年 | 1513篇 |
2004年 | 1369篇 |
2003年 | 1203篇 |
2002年 | 1188篇 |
2001年 | 926篇 |
2000年 | 885篇 |
1999年 | 788篇 |
1998年 | 712篇 |
1997年 | 542篇 |
1996年 | 437篇 |
1995年 | 429篇 |
1994年 | 386篇 |
1993年 | 311篇 |
1992年 | 280篇 |
1991年 | 222篇 |
1990年 | 197篇 |
1989年 | 153篇 |
1988年 | 152篇 |
1987年 | 153篇 |
1986年 | 139篇 |
1985年 | 156篇 |
1984年 | 146篇 |
1983年 | 81篇 |
1982年 | 123篇 |
1981年 | 73篇 |
1980年 | 41篇 |
1979年 | 46篇 |
1978年 | 39篇 |
1977年 | 36篇 |
1976年 | 30篇 |
1973年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Consider a sequenceF
1,F
2,... of i.i.d. random transformations from a countable setV toV. Such a sequence describes a discrete-time stochastic flow onV, in which the position at timen of a particle that started at sitex isM
n(x), whereM
n
=F
n
F
n–1
F
1. We give conditions on the law ofF
1 for the sequence (M
n) to be tight, and describe the possible limiting law. an example called the block charge model is introduced. The results can be formulated as a statement about the convergence in distribution of products of infinite-dimensional random stochastic matrices. In practical terms, they describe the possible equilibria for random motions of systems of particles on a countable set, without births or deaths, where each site may be occupied by any number of particles, and all particles at a particular site move together. 相似文献
992.
993.
B. Alabi 《Applied Mathematical Modelling》1989,13(12):710-715
This paper presents a three-dimensional model for the analysis of ground vibrations excited by forces transmitted to the ground from the wheels of a moving train through the track. The field equations are solved by using scalar wave functions. From the computed results presented here, certain qualitative conclusions can be made to enhance our understanding of the physical problem. 相似文献
994.
995.
996.
Deuteron electromagnetic form factors and tensor polarization observables in the framework of the hard-wall AdS/QCD model 下载免费PDF全文
We study the electromagnetic form factors and tensor polarization observables of the deuteron in the framework of the hard-wall AdS/QCD model. We find a profile function for the bulk twist \begin{document}$\tau=6$\end{document} ![]()
![]()
vector field, which describes the deuteron on the boundary and fix the infrared boundary cut-off of AdS space in accordance with the ground state mass of the deuteron. We obtain the deuteron charge monopole, quadrupole, and magnetic dipole form factors and tensor polarization observables from the bulk Lagrangians for the deuteron and photon field interactions. We plot the momentum transfer dependence of the form factors and tensor polarization observables and compare our numerical results with those in the soft-wall model and experimental data. 相似文献
997.
X-ray photoemission spectra, resistivity and susceptibility of CeNi2Sb2 and CeCu2Sb2 were measured and are discussed. The results indicate that these alloys are Kondo systems. For comparison of the valence band properties, the spectra of the isostructural alloys of RT2X2-type with R = La, Gd, T = Cu, Ni and X = Sn, Sb were investigated, too. 相似文献
998.
On diffuse reflection at the boundary for the Boltzmann equation and related equations 总被引:1,自引:0,他引:1
The paper considers diffuse reflection at the boundary with nonconstant boundary temperature and unbounded velocities. The solutions obtained are proved to conserve mass at the boundary. After a preliminary study of the collisionless case, the main results obtained are existence for the Boltzmann equation in a DiPerna-Lions framework with the above boundary conditions in a bounded measure sense, and existence together with uniqueness for the BGK equation with Maxwellian diffusion on the boundary in anL
framework.Deceased. 相似文献
999.
1000.
Paul H. E. Meijer 《Journal of statistical physics》1988,53(1-2):543-548
The simple Flory-Huggins model can be combined with the lattice gas as was done by Tompa and others. Here the same method is used to obtain the van der Waals equation of state for a binary gas-liquid system containing a solute consisting of segmented molecules. The simplified equation of state developed here is useful for the study of the critical properties of such systems, in particular, the dependence of the various parameters on the chain length of the molecules. 相似文献