全文获取类型
收费全文 | 617篇 |
免费 | 61篇 |
国内免费 | 35篇 |
专业分类
化学 | 20篇 |
晶体学 | 2篇 |
力学 | 18篇 |
综合类 | 11篇 |
数学 | 253篇 |
物理学 | 409篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 7篇 |
2021年 | 8篇 |
2020年 | 18篇 |
2019年 | 17篇 |
2018年 | 12篇 |
2017年 | 9篇 |
2016年 | 17篇 |
2015年 | 17篇 |
2014年 | 31篇 |
2013年 | 30篇 |
2012年 | 16篇 |
2011年 | 42篇 |
2010年 | 33篇 |
2009年 | 48篇 |
2008年 | 39篇 |
2007年 | 44篇 |
2006年 | 41篇 |
2005年 | 36篇 |
2004年 | 30篇 |
2003年 | 28篇 |
2002年 | 27篇 |
2001年 | 16篇 |
2000年 | 21篇 |
1999年 | 21篇 |
1998年 | 9篇 |
1997年 | 17篇 |
1996年 | 9篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有713条查询结果,搜索用时 31 毫秒
91.
By using the semi-analytic approach introduced earlier, we formulate and subsequently evaluate the irradiance fluctuations of partially coherent super Lorentz Gaussian beams for orders of 10 and 11. Within the range of examined source and propagation conditions, our calculations show that there will be less fluctuations at short propagation distances as the Lorentzian property is increased. But the reverse will be applicable, if the longer propagation distances are considered. The use of focusing will cause reductions, particularly for beams with increased Lorentzian property. 相似文献
92.
M. Napsuciale M. Kirchbach S. Rodriguez 《The European Physical Journal A - Hadrons and Nuclei》2006,29(3):289-306
We employ the two independent Casimir operators of the Poincaré group, the squared four-momentum, p2, and the squared Pauli-Lubanski vector, W2, in the construction of a covariant mass m, and spin-
projector in the four-vector spinor, ψμ. This projector provides the basis for the construction of an interacting Lagrangian that describes a causally propagating
spin-
particle coupled to the electromagnetic field by a gyromagnetic ratio of
. 相似文献
93.
In the previous paper, we report line strength measurements for 58 bands of 12CO2 between 4550 and 7000 cm−1 [R.A. Toth, L.R. Brown, C.E. Miller, V. Malathy Devi, D. Chris Benner, J. Mol. Spectrosc., this issue, doi:10.1016/j.jms.2006.008.001.]. In the present study, self-broadenedwidth and self-induced pressure shift coefficients are determined in two intervals:
- (a) between 4750 and 5400 cm−1for bands of the Fermi triad (20011 ← 00001, 20012 ← 00001, 20013 ← 00001), three corresponding hot bands (21111 ← 01101, 21112 ← 01101, 21113 ← 01101) and the 01121← 00001 combination band;
- (b) between 6100 and 7000 cm−1 for the Fermi tetrad (30014 ← 00001, 30013 ← 00001, 30012 ← 00001, 30011 ← 00001), two associated hot bands (31113 ← 01101, 31112 ← 01101), as well as 00031 ← 00001 and its hot band 01131 ← 01101.
94.
O. W. Greenberg 《Foundations of Physics》2006,36(10):1535-1553
Lüders and Pauli proved the theorem based on Lagrangian quantum field theory almost half a century ago. Jost gave a more general proof based on “axiomatic” field theory nearly as long ago. The axiomatic point of view has two advantages over the Lagrangian one. First, the axiomatic point of view makes clear why is fundamental—because it is intimately related to Lorentz invariance. Secondly, the axiomatic proof gives a simple way to calculate the transform of any relativistic field without calculating , and separately and then multiplying them. The purpose of this pedagogical paper is to “deaxiomatize” the theorem by explaining it in a few simple steps. We use theorems of distribution theory and of several complex variables without proof to make the exposition elementary. 相似文献
95.
C. Novotny B. Bernhardt G. Ewald C. Geppert G. Gwinner T. W. Hänsch R. Holzwarth G. Huber S. Karpuk H.-J. Kluge T. Kühl W. Nörtershäuser S. Reinhardt G. Saathoff D. Schwalm T. Udem A. Wolf 《Hyperfine Interactions》2006,171(1-3):57-67
The Doppler-free laser-spectroscopic frequency measurement of Doppler-shifted optical lines in forward and backward direction
of a fast ion beam permits a sensitive test of the relativistic Doppler-formula and, hence, the relativistic time dilation
factor . An experiment on metastable 7Li+, stored at a velocity of v = 0.064c in the Heidelberg heavy-ion storage ring TSR, has confirmed time dilation with unprecedented accuracy. Latest tests at two
different ion-velocities (v = 0.03c and v = 0.064c) will enhance these measurements. An improved version of this experiment will be carried out at the experimental storage
ring (ESR) at the Gesellschaft für Schwerionenforschung (GSI) in Darmstadt. The ESR permits 7Li+ to be stored at v = 0.33c which promises an improvement of the sensitivity to deviations from γ
SR by an order of magnitude. A first test at the ESR has shown the feasibility for this kind of experiment. 相似文献
96.
分布在弱电介质溶液中的电磁力(Lorentz力),可以有效地控制边界层的流动.利用以转动水槽为主的实验系统和基于双时间步Roe格式的数值方法,对翼型绕流的电磁控制进行了实验和数值研究.结果表明,对于一定攻角的翼型,电磁力可以控制其绕流形态.当电磁力方向与流动方向相同时,可以抑制分离,消除涡街,其效果与减小攻角类似.当电磁力的方向与流动方向相反时,可在流场中形成大涡组成的涡街,增强流体的混合能力,其效果与增大攻角类似. 相似文献
97.
By using hyperbolic virtual unit of Clifford algebra, the concept of n-dimensional space-time unit spheres is introduced. It is used as n-dimensional Minkowski space-time and Lorentz transformation. 相似文献
98.
F. Selleri 《Foundations of Physics Letters》2003,16(1):71-82
Transformations of space and time, depending on a synchronisation parameter e
1, indicate the existence of a privileged inertial system S
0. The Lorentz transformations are obtained for a particular e
10. No classical experiment on relativity is expected to depend on the choice of e
1. We show, consistently with expectations, that the result of the Fizeau experiment is explained equally well by theories adopting different values of e
1. In previous papers we showed that if accelerated reference frames are considered only e
1=0 remains possible. 相似文献
99.
Jesú s Bastero Mario Milman Francisco J. Ruiz 《Proceedings of the American Mathematical Society》2000,128(1):65-74
For the classical Hardy-Littlewood maximal function , a well known and important estimate due to Herz and Stein gives the equivalence . In the present note, we study the validity of analogous estimates for maximal operators of the form
where denotes the Lorentz space -norm.
100.
Some estimates on 2-D Euler equations are given when initial vorticity ω0 belongs to a Lorentz space L(2, 1). Then based on these estimates, it is proved that there exist global weak solutions of two dimensional Euler equations when ωo ∈ L(2, 1). 相似文献