全文获取类型
收费全文 | 12413篇 |
免费 | 3353篇 |
国内免费 | 1292篇 |
专业分类
化学 | 4389篇 |
晶体学 | 85篇 |
力学 | 33篇 |
综合类 | 82篇 |
数学 | 885篇 |
物理学 | 11584篇 |
出版年
2024年 | 49篇 |
2023年 | 207篇 |
2022年 | 507篇 |
2021年 | 552篇 |
2020年 | 502篇 |
2019年 | 454篇 |
2018年 | 419篇 |
2017年 | 430篇 |
2016年 | 600篇 |
2015年 | 540篇 |
2014年 | 773篇 |
2013年 | 1003篇 |
2012年 | 805篇 |
2011年 | 986篇 |
2010年 | 766篇 |
2009年 | 761篇 |
2008年 | 970篇 |
2007年 | 916篇 |
2006年 | 889篇 |
2005年 | 755篇 |
2004年 | 661篇 |
2003年 | 563篇 |
2002年 | 542篇 |
2001年 | 391篇 |
2000年 | 444篇 |
1999年 | 289篇 |
1998年 | 317篇 |
1997年 | 197篇 |
1996年 | 134篇 |
1995年 | 110篇 |
1994年 | 77篇 |
1993年 | 63篇 |
1992年 | 64篇 |
1991年 | 52篇 |
1990年 | 53篇 |
1989年 | 47篇 |
1988年 | 24篇 |
1987年 | 18篇 |
1986年 | 25篇 |
1985年 | 24篇 |
1984年 | 18篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 9篇 |
1978年 | 7篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1972年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Examples are worked out using a new equation proposed in the previous paper to show that it has new physical predictions for mesoscopic systems. 相似文献
32.
33.
Kouichi Akahane Naokatsu Yamamoto Naoki Ohtani 《Physica E: Low-dimensional Systems and Nanostructures》2004,21(2-4):295
We fabricated InAs quantum dots (QDs) with a GaAsSb strain-reducing layer (SRL) on a GaAs(0 0 1) substrate. The wavelength of emission from InAs QD is shown to be controllable by changing the composition and thickness of the SRL. An increase in photoluminescence intensity with increasing compositions of Sb and thickness of the GaAsSb SRL is also seen. The efficiency of radiative recombination was improved under both conditions because the InAs/GaAsSb/GaAs hetero-interface band structure more effectively suppressed carrier escape from the InAs QDs. 相似文献
34.
X-ray diffraction patterns of nanocrystalline Fe-Cu-Nb-Si-B (FINEMET) alloys reveal that bcc α-Fe/α-FeSi crystallites with
the average grain size of 20(5) nm are dispersed in amorphous matrix. Enhanced electron—electron interaction (EEI) and quantum
interference (QI) effects as well as electron-magnon (and/or electron-spin fluctuation) scattering turn out to be the main
mechanisms that govern the temperature dependence of resistivity. Of all the inelastic scattering processes, inelastic electron-phonon
scattering is the most effective mechanism to destroy phase coherence of electron wave functions. The diffusion constant,
density of states at the Fermi level and the inelastic scattering time have been estimated, for the first time, for the alloys
in question
Article presented at the International Symposium on Advances in Superconductivity and Magnetism: Materials, Mechanisms and
Devices, ASMM2D-2001, 25–28 September 2001, Mangalore, India. 相似文献
35.
S. J. Cheng W. Sheng P. Hawrylak S. Raymond S. Studenikin A. Sachrajda Z. Wasilewski A. Babinski M. Potemski G. Ortner M. Bayer 《Physica E: Low-dimensional Systems and Nanostructures》2004,21(2-4):211
We present results of calculations and experiments on electron–hole complexes in InGaAs/GaAs self-assembled quantum dots in high magnetic field (B). Due to hidden symmetries, the chemical potential of an N-exciton system at special B fields becomes insensitive to the exciton number as well as the magnetic field. This results in plateau regions of high intensity in measured magneto-PL spectrum. Theoretical calculations using exact diagonalization techniques successfully explain the measured magneto-photoluminescence spectrum with B fields up to 28 T. 相似文献
36.
A. Khrennikov 《Annalen der Physik》2003,12(10):575-585
We study the probabilistic consequences of the choice of the basic number field in the quantum formalism. We demonstrate that by choosing a number field for a linear space representation of quantum model it is possible to describe various interference phenomena. We analyse interference of probabilistic alternatives induced by real, complex, hyperbolic (Clifford) and p‐adic representations. 相似文献
37.
38.
39.
M. Castagnino R. Id Betan R. Laura 《International Journal of Theoretical Physics》2003,42(10):2423-2439
By extending the notion of mixed states to functionals acting on the space of observables with diagonal singularity we obtain a well-defined complex spectral decomposition of the time evolution for a quantum decaying system. In this formalism, generalized Gamow states are obtained with well-defined physical properties. 相似文献
40.
Dimitar I. Pushkarov 《Central European Journal of Physics》2004,2(3):420-455
Basic ideas and results which characterize quantum diffusion of defects in quantum crystals like solid helium as a new phenomenon
are presented. Quantum effects in such media lead to a delocalization of point defects (vacancies, impurities etc.) and they
turn into quasiparticles of a new type—defectons, which are characterized not by their position in the crystal lattice but
by their quasimomentum and dispersion law. Defecton-defecton and defecton-phonon scattering are considered and an interpolation
formula for the diffusion coefficient valid in all interesting temperature and concentration regions is presented. A comparison
with the experimental data is made. Some alternative points of view are discussed in detail and the inconsistency of the Kisvarsanyi-Sullivan
theory is shown. 相似文献