全文获取类型
收费全文 | 248篇 |
免费 | 5篇 |
国内免费 | 11篇 |
专业分类
化学 | 132篇 |
力学 | 13篇 |
数学 | 74篇 |
物理学 | 45篇 |
出版年
2023年 | 2篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2016年 | 4篇 |
2015年 | 8篇 |
2014年 | 3篇 |
2013年 | 11篇 |
2012年 | 25篇 |
2011年 | 17篇 |
2010年 | 10篇 |
2009年 | 8篇 |
2008年 | 17篇 |
2007年 | 13篇 |
2006年 | 13篇 |
2005年 | 11篇 |
2004年 | 4篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1986年 | 3篇 |
1984年 | 4篇 |
1982年 | 2篇 |
1981年 | 9篇 |
1980年 | 3篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 7篇 |
1971年 | 1篇 |
1966年 | 1篇 |
1929年 | 1篇 |
1926年 | 1篇 |
1922年 | 1篇 |
1915年 | 2篇 |
1908年 | 5篇 |
1907年 | 1篇 |
1876年 | 1篇 |
排序方式: 共有264条查询结果,搜索用时 0 毫秒
71.
Luin S Pellegrini V Pinczuk A Dennis BS Pfeiffer LN West KW 《Physical review letters》2003,90(23):236802
Inelastic light-scattering measurements of low-lying collective excitations of electron double layers in the quantum Hall state at total filling nu(T)=1 reveal a deep magnetoroton in the dispersion of charge-density excitations across the tunneling gap. The roton softens and sharpens markedly when the phase boundary for transitions to highly correlated compressible states is approached. The findings are interpreted with Hartree-Fock evaluations that link soft magnetorotons to enhanced excitonic Coulomb interactions and to quantum phase transitions in the ferromagnetic bilayers. 相似文献
72.
We study the influence of asymmetric coupling strengths on the onset of light intensity oscillations in an experimental system consisting of two semiconductor lasers cross coupled optoelectronically with a time delay. We discover a scaling law that relates the amplitudes of oscillations and the coupling strengths. These observations are in agreement with a theoretical model. These results could be applicable to the population dynamics of other systems, such as the spread of disease in human populations coupled by migration. 相似文献
73.
Tel T Karolyi G Pentek A Scheuring I Toroczkai Z Grebogi C Kadtke J 《Chaos (Woodbury, N.Y.)》2000,10(1):89-98
We review and generalize recent results on advection of particles in open time-periodic hydrodynamical flows. First, the problem of passive advection is considered, and its fractal and chaotic nature is pointed out. Next, we study the effect of weak molecular diffusion or randomness of the flow. Finally, we investigate the influence of passive advection on chemical or biological activity superimposed on open flows. The nondiffusive approach is shown to carry some features of a weak diffusion, due to the finiteness of the reaction range or reaction velocity. (c) 2000 American Institute of Physics. 相似文献
74.
75.
J. C. Aron 《Foundations of Physics》1981,11(11-12):863-872
The stochastic approach worked out in earlier papers is applied to the Dirac fluid. It gives a model of the Schrödinger zitterbewegung, from which, by the spinor-vector correspondence, a model of the plane monochromatic wave in the rest frame is derived. The relation of the scheme with quantization is found to have the same character as in the previous papers. The link of spin with relativity is explained. 相似文献
76.
77.
It is shown that every n-homogeneous continuous polynomial on a Banach space E which is weakly continuous on the unit ball of E is weakly uniformly continuous on the unit ball of E. Applications of the result to spaces of polynomials and holomorphic mappings on E are given. 相似文献
78.
Low energy, variable angle, electron-impact energy-loss spectra of nitromethane have been obtained. A previously unreported singlet → triplet excitation with maximum intensity at 3.8 eV energy loss is observed and its relevance to the gas phase photochemistry of nitromethane is discussed. An additional weak transition with maximum intensity at 4.45 eV energy loss is tentatively assigned to a symmetry-forbidden transition. 相似文献
79.
Jeffrey A. Sell Aron Kuppermann Donald M. Mintz 《Journal of Electron Spectroscopy and Related Phenomena》1979,16(2):127-145
The angular distributions of the photoelectron intensity for CO have been investigated using a photoelectron spectrometer that has a rotatable detector and an HeI light source. The asymmetry parameter β was carefully measured for 24 vibrational transitions spanning three ionization bands. Its variation with final-state vibrational quantum number was found to have an unusual behavior. It is concluded that an autoionizing state of CO should exist at 584 Å in order to account for this behavior, and that the value of β is very sensitive to the presence of such a state. 相似文献
80.
Electron-impact energy-loss spectra of 1,3-butadiene have been obtained at impact energies from 35 eV to 90 eV, at a scattering angle of 0°, and at a 相似文献