全文获取类型
收费全文 | 32069篇 |
免费 | 6805篇 |
国内免费 | 2973篇 |
专业分类
化学 | 8455篇 |
晶体学 | 124篇 |
力学 | 2834篇 |
综合类 | 650篇 |
数学 | 11107篇 |
物理学 | 18677篇 |
出版年
2024年 | 78篇 |
2023年 | 392篇 |
2022年 | 861篇 |
2021年 | 1034篇 |
2020年 | 995篇 |
2019年 | 899篇 |
2018年 | 881篇 |
2017年 | 1123篇 |
2016年 | 1386篇 |
2015年 | 1165篇 |
2014年 | 1824篇 |
2013年 | 2392篇 |
2012年 | 1868篇 |
2011年 | 2133篇 |
2010年 | 1839篇 |
2009年 | 1996篇 |
2008年 | 2355篇 |
2007年 | 2392篇 |
2006年 | 2080篇 |
2005年 | 1865篇 |
2004年 | 1715篇 |
2003年 | 1492篇 |
2002年 | 1410篇 |
2001年 | 1104篇 |
2000年 | 1064篇 |
1999年 | 887篇 |
1998年 | 808篇 |
1997年 | 649篇 |
1996年 | 513篇 |
1995年 | 492篇 |
1994年 | 321篇 |
1993年 | 289篇 |
1992年 | 222篇 |
1991年 | 250篇 |
1990年 | 177篇 |
1989年 | 131篇 |
1988年 | 137篇 |
1987年 | 89篇 |
1986年 | 84篇 |
1985年 | 91篇 |
1984年 | 65篇 |
1983年 | 39篇 |
1982年 | 42篇 |
1981年 | 50篇 |
1980年 | 35篇 |
1979年 | 29篇 |
1978年 | 26篇 |
1977年 | 15篇 |
1976年 | 14篇 |
1974年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
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
93.
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
94.
95.
96.
By using the quasi-Lyapunov function, some sufficient conditions of global exponential stability for impulsive systems are established, which is the basis for the following discussion. Then, by employing Riccati inequality and Hamilton-Jacobi inequality approach, some sufficient conditions of robust exponential stability for uncertain linear/nonlinear impulsive systems are derived, respectively. Finally, some examples are given to illustrate the applications of the theory. 相似文献
97.
Tsutomu KumagaiMasaaki Tomura Jun-ichi NishidaYoshiro Yamashita 《Tetrahedron letters》2003,44(36):6845-6848
1,3-Dithiol-2-ylidene derivatives containing bis(ethynylpyridine) units were synthesized using a Pd-catalyzed reaction of the corresponding dibromide. X-Ray crystal analysis revealed unique crystal structures depending on the aromatic groups. The absorption spectra and redox properties indicated intramolecular charge-transfer interactions between the 1,3-dithiole unit and the pyridyl parts. 相似文献
98.
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
99.
100.
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