全文获取类型
收费全文 | 2935篇 |
免费 | 363篇 |
国内免费 | 221篇 |
专业分类
化学 | 795篇 |
晶体学 | 15篇 |
力学 | 503篇 |
综合类 | 35篇 |
数学 | 856篇 |
物理学 | 1315篇 |
出版年
2024年 | 2篇 |
2023年 | 38篇 |
2022年 | 71篇 |
2021年 | 66篇 |
2020年 | 105篇 |
2019年 | 79篇 |
2018年 | 90篇 |
2017年 | 116篇 |
2016年 | 116篇 |
2015年 | 78篇 |
2014年 | 154篇 |
2013年 | 199篇 |
2012年 | 154篇 |
2011年 | 159篇 |
2010年 | 159篇 |
2009年 | 191篇 |
2008年 | 215篇 |
2007年 | 178篇 |
2006年 | 161篇 |
2005年 | 182篇 |
2004年 | 157篇 |
2003年 | 137篇 |
2002年 | 108篇 |
2001年 | 95篇 |
2000年 | 55篇 |
1999年 | 54篇 |
1998年 | 53篇 |
1997年 | 46篇 |
1996年 | 44篇 |
1995年 | 29篇 |
1994年 | 28篇 |
1993年 | 24篇 |
1992年 | 19篇 |
1991年 | 22篇 |
1990年 | 22篇 |
1989年 | 9篇 |
1988年 | 14篇 |
1987年 | 13篇 |
1986年 | 12篇 |
1985年 | 6篇 |
1984年 | 9篇 |
1983年 | 4篇 |
1982年 | 8篇 |
1981年 | 9篇 |
1980年 | 10篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1976年 | 2篇 |
1974年 | 2篇 |
1971年 | 2篇 |
排序方式: 共有3519条查询结果,搜索用时 31 毫秒
11.
Guy Bayada 《Journal of Mathematical Analysis and Applications》2003,282(1):212-231
The asymptotic behaviour of a Stokes flow with Tresca free boundary friction conditions when one dimension of the fluid domain tends to zero is studied. A specific Reynolds equation associated with variational inequalities is obtained and uniqueness is proved. 相似文献
12.
通过建立能够自洽地描述核子和反核子束缚态的相对论Hartree模型来研究有限核中的量子真空,其中狄拉克海对介子场方程的贡献由单圈图考虑,模型中还引入了ω介子和ρ介子的张量耦合项.在拟合球形核的性质后得到模型的参数,给出核子有效质量为m*/MN≈0.78;计算得到的核子壳模型能级与实验值相一致,在考虑张量耦合项的效应后真空反核子位阱深度增大了20—30MeV. 相似文献
13.
14.
15.
A. A. Dokukin 《Computational Mathematics and Mathematical Physics》2006,46(5):914-918
To validate approximate optimization schemes for estimate calculation algorithms (ECAs), it is necessary to compute the optimal height, which cannot be done in a reasonable amount of time. A variety of samples are built for which the optimal height of the ECAs is known by construction. 相似文献
16.
We have investigated the free energy of formation for AgxIn1-x and AgxSn1-x liquid binary alloys at temperatures 1173 and 1250 K, respectively. A microscopic theory based on the first order perturbation has been applied. The interionic interaction and a reference liquid are the fundamental components of the theory. The interionic interaction is described by a local pseudopotential. A liquid of hard spheres (HS) of two different effective diametres and charges is used to describe the reference system. The results of the calculations for energy of formation agree very well with the available experimental data. Our calculations also reveal that a simple perturbative approach along with appropriate effective pair potentials can produce nearly quantitative results for the concerned alloys. 相似文献
17.
M.B. Xu 《Applied Acoustics》2003,64(7):731-752
The forced vibration of an infinite elastic circular cylindrical shell filled with fluid is studied. Three methods are employed to analyze the forced vibration problem of this shell-fluid coupled system, that is, wave propagation approach (wave mode superposition), theorem of residues and a numerical integral method. In order to explain these methods more explicitly, before being used to investigate the vibration of an infinite fluid-filled elastic circular cylindrical shell, all these three methods are employed firstly to analyze the forced vibration problem of an infinite beam and an infinite elastic circular cylindrical shell in vacuo. Advantage and disadvantage of these three methods are discussed and their interesting relationship is revealed. That is, to any circumferential wavenumber and frequency of the external force, there is an unchangeable relationship between the general coordinates of various waves in the wave propagation approach and the residuals in the theorem of residues. 相似文献
18.
19.
Two structure functions W1(x,Q2) and W2(x,Q2) are determined by using the cross sections measured in the deep inelastic electron-proton scattering experiments at Stanford Linac in the energy range of 5 to 20 GeV. In this paper an alternative mathematical approach have been used in such determination, resulting in a larger number of points in the graphs of the structure functions. 相似文献
20.
We formulate and solve the problem of finding a distribution function F(r,p,t) such that calculating statistical averages leads to the same local values of the number of particles, the momentum, and the energy as those in quantum mechanics. The method is based on the quantum mechanical definition of the probability density not limited by the number of particles in the system. The obtained distribution function coincides with the Wigner function only for spatially homogeneous systems. We obtain the chain of Bogoliubov equations, the Liouville equation for quantum distribution functions with an arbitrary number of particles in the system, the quantum kinetic equation with a self-consistent electromagnetic field, and the general expression for the dielectric permittivity tensor of the electron component of the plasma. In addition to the known physical effects that determine the dispersion of longitudinal and transverse waves in plasma, the latter tensor contains a contribution from the exchange Coulomb correlations significant for dense systems. 相似文献