全文获取类型
收费全文 | 560篇 |
免费 | 49篇 |
国内免费 | 71篇 |
专业分类
化学 | 64篇 |
力学 | 48篇 |
综合类 | 2篇 |
数学 | 28篇 |
物理学 | 538篇 |
出版年
2023年 | 5篇 |
2022年 | 10篇 |
2021年 | 8篇 |
2020年 | 14篇 |
2019年 | 16篇 |
2018年 | 15篇 |
2017年 | 15篇 |
2016年 | 15篇 |
2015年 | 17篇 |
2014年 | 20篇 |
2013年 | 19篇 |
2012年 | 18篇 |
2011年 | 24篇 |
2010年 | 38篇 |
2009年 | 73篇 |
2008年 | 38篇 |
2007年 | 37篇 |
2006年 | 39篇 |
2005年 | 26篇 |
2004年 | 17篇 |
2003年 | 37篇 |
2002年 | 16篇 |
2001年 | 29篇 |
2000年 | 28篇 |
1999年 | 16篇 |
1998年 | 22篇 |
1997年 | 13篇 |
1996年 | 2篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1985年 | 1篇 |
1984年 | 5篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1977年 | 3篇 |
1971年 | 1篇 |
排序方式: 共有680条查询结果,搜索用时 15 毫秒
71.
Taking the conservation of baryon number into account in a non-uniform flow model, the rapidity distribution of the net protons at the LHC is predicted. The energy dependence of the rapidity distribution, baryon stopping and collective flow from BNL/AGS to CERN/LHC are systematically investigated. 相似文献
72.
Ri-Xing Wang Quan-Hui Liu An-Lian Pan Yan-Guo Wang 《Journal of magnetism and magnetic materials》2010,322(15):2264-2267
A theoretical study is presented on the current-driven ferromagnetic resonance in the magnetic trilayers. On the basis of the Landau-Lifshitz-Gilbert-Slonczewski equation, we derive the output dc voltage for arbitrary anisotropy in the free and pinned layers by the linearization method. As an example, the resonance spectra of the tilted-polarizer and perpendicular-analyzer trilayer show that the equilibrium position, the resonant linewidth and the resonant location can be tuned by changing the magnitude and the direction of spin torque. The effective damping can be minimized through adjusting the current and the pinned-layer magnetization direction. 相似文献
73.
We evaluate the radiative decay into a vector, a pseudoscalar and a photon of several resonances dynamically generated from the vector–vector interaction. The process proceeds via the decay of one of the vector components into a pseudoscalar and a photon, which have an invariant mass distribution very different from phase space as a consequence of the two vector structure of the resonances. Experimental work along these lines should provide useful information on the nature of these resonances. 相似文献
74.
The high-resolution infrared spectrum of deuterated fluoroform (DCF3) was studied in the 700 and 1200 cm−1 regions, with the aim of assigning and analyzing the ν4 CF3 asymmetric stretching vibration. The Fermi-type anharmonic coupling between the ν4 = 1 and ν3 = ν6 = 1 rovibrational levels, already mentioned in an early work of Ruoff et al. [Spectrochimica Acta Part A 31A (1975) 1099-1100], was studied here for the first time under high resolution. Assignments in the ν3 + ν6/ν4 band system were confirmed and extended by the identification of the ν3 + ν6 − ν6 and ν4-ν6 bands in the 700 cm−1 region, the latter being enhanced near the Fermi crossings of the studied levels. Data from both the hot and difference bands were included in the analysis. The close separation of the studied vibrational levels of about 14.8 cm−1 produces a large variety of resonance crossings which involve levels with . Besides the Fermi () and Coriolis () resonances, they were accounted for by inclusion of additional higher-order ( and ) interaction terms between the vibrational states. The least-squares fit of more that 16,000 vibration-rotation transitions provides a quantitative reproduction of data in all bands. 相似文献
75.
76.
Using previously determined interatomic potentials, the activation energy for migration of a single substitutional helium atom in copper and tungsten has been determined. The mechanism of migration involves the jump of the helium atom out of the vacancy concurrent with the jump of a host atom into that vacancy. The helium then occupies the vacant site created by the jumping host atom, resulting in a substitutional helium at a distance of √2 r 0 (√3r 0) from its original site in copper (tungsten). The rate-limiting step in the process is found to be the jump of the helium out of the vacancy, the activation energy for which is 2.15 eV in copper and 4.69 eV in tungsten. 相似文献
77.
R. Alkofer C. S. Fischer R. Williams 《The European Physical Journal A - Hadrons and Nuclei》2008,38(1):53-60
The U
A(1) problem of QCD is inevitably tied to the infrared behaviour of quarks and gluons with its most visible effect being the
-mass. A dimensional argument of Kogut and Susskind showed that the mixing of the pseudoscalar flavour-singlet mesons with
gluons can provide a screening of the Goldstone pole in this channel if the full quark-quark interaction is strongly infrared
singular as ∼ 1/k
4 . We investigate this idea using previously obtained results for the Landau gauge ghost and gluon propagator, together with
recent determinations for the singular behaviour of the quark-gluon vertex. We find that, even with an infrared vanishing
gluon propagator, the singular structure of the quark-gluon vertex for certain kinematics is apposite for yielding a non-zero
screening mass. 相似文献
78.
E. Klempt 《The European Physical Journal A - Hadrons and Nuclei》2008,38(2):187-194
The mass spectrum of Δ -resonances is compared to predictions based on three quark-model variants, to predictions assuming
that chiral symmetry is restored in high-mass baryon resonances, and to predictions derived from AdS/QCD. The latter approach
yields a nearly perfect agreement when the confinement property of QCD is modeled by a soft wall in AdS. 相似文献
79.
A high resolution (0.0018 cm−1) Fourier transform instrument has been used to record the spectrum of an enriched 34S (95.3%) sample of sulfur dioxide. A thorough analysis of the ν2, 2ν2 − ν2, ν1, ν1 + ν2 − ν2, ν3, ν2 + ν3 − ν2, ν1 + ν2 and ν2 + ν3 bands has been carried out leading to a large set of assigned lines. From these lines ground state combination differences were obtained and fit together with the existing microwave, millimeter, and terahertz rotational lines. An improved set of ground state rotational constants were obtained. Next, the upper state rotational levels were fit. For the (0 1 0), (1 1 0) and (0 1 1) states, a simple Watson-type Hamiltonian sufficed. However, it was necessary to include explicitly interacting terms in the Hamiltonian matrix in order to fit the rotational levels of the (0 2 0), (1 0 0) and (1 0 1) states to within their experimental accuracy. More explicitly, it was necessary to use a ΔK = 2 term to model the Fermi interaction between the (0 2 0) and (1 0 0) levels and a ΔK = 3 term to model the Coriolis interaction between the (1 0 0) and (0 0 1) levels. Precise Hamiltonian constants were derived for the (0 0 0), (0 1 0), (1 0 0), (0 0 1), (0 2 0), (1 1 0) and (0 1 1) vibrational states. 相似文献