全文获取类型
收费全文 | 10343篇 |
免费 | 215篇 |
国内免费 | 8篇 |
专业分类
化学 | 5929篇 |
晶体学 | 197篇 |
力学 | 207篇 |
数学 | 1742篇 |
物理学 | 2491篇 |
出版年
2022年 | 129篇 |
2021年 | 140篇 |
2020年 | 121篇 |
2019年 | 164篇 |
2018年 | 153篇 |
2017年 | 160篇 |
2016年 | 271篇 |
2015年 | 231篇 |
2014年 | 294篇 |
2013年 | 674篇 |
2012年 | 419篇 |
2011年 | 490篇 |
2010年 | 386篇 |
2009年 | 357篇 |
2008年 | 422篇 |
2007年 | 403篇 |
2006年 | 354篇 |
2005年 | 301篇 |
2004年 | 268篇 |
2003年 | 289篇 |
2002年 | 220篇 |
2001年 | 190篇 |
2000年 | 179篇 |
1999年 | 138篇 |
1998年 | 143篇 |
1997年 | 119篇 |
1996年 | 116篇 |
1995年 | 145篇 |
1994年 | 94篇 |
1993年 | 84篇 |
1992年 | 102篇 |
1991年 | 89篇 |
1990年 | 112篇 |
1989年 | 98篇 |
1988年 | 102篇 |
1987年 | 88篇 |
1986年 | 94篇 |
1985年 | 137篇 |
1984年 | 154篇 |
1983年 | 97篇 |
1982年 | 111篇 |
1981年 | 123篇 |
1980年 | 130篇 |
1979年 | 104篇 |
1978年 | 107篇 |
1977年 | 99篇 |
1976年 | 89篇 |
1975年 | 91篇 |
1974年 | 69篇 |
1973年 | 68篇 |
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
31.
We characterize Poisson and Jacobi structures by means of complete lifts of the corresponding tensors: the lifts have to be
related to canonical structures by morphisms of corresponding vector bundles. Similar results hold for generalized Poisson
and Jacobi structures (canonical structures) associated with Lie algebroids and Jacobi algebroids. 相似文献
32.
The existence of a Nash equilibrium in the undiscounted repeated two-person game of incomplete information on one side is
established. The proof depends on a new topological result resembling in some respect the Borsuk-Ulam theorem. 相似文献
33.
Prot Pakoński Gregor Tanner Karol Życzkowski 《Journal of statistical physics》2003,111(5-6):1331-1352
Any directed graph G with N vertices and J edges has an associated line-graph L(G) where the J edges form the vertices of L(G). We show that the non-zero eigenvalues of the adjacency matrices are the same for all graphs of such a family L
n
(G). We give necessary and sufficient conditions for a line-graph to be quantisable and demonstrate that the spectra of associated quantum propagators follow the predictions of random matrices under very general conditions. Line-graphs may therefore serve as models to study the semiclassical limit (of large matrix size) of a quantum dynamics on graphs with fixed classical behaviour. 相似文献
34.
35.
W. Królas A. Maj P. Bednarczyk B. Fornal W. Mceczynski J. Styczeń M. Zicebliński 《Zeitschrift für Physik A Hadrons and Nuclei》1992,344(2):145-147
High-energy gamma-rays emitted in the decay of the giant dipole resonance built on excited states of55Mn nucleus were measured with a bismuth germanate detector. Resonance parameters were extracted from the fits to the experimental spectra. Two new high-energy calibration points originating from slow-neutron capture in germanium isotopes of bismuth germanate crystal are proposed for large-volume BGO detectors. 相似文献
36.
We study linear dynamical systems with multidimensional time in Banach spaces. Using Taylor functional calculus we prove that under additional assumptions hyperbolic systems have shadowing property. 相似文献
37.
38.
Orotic acid (vitamin B13) is a key intermediate in biosynthesis of the pyrimidine nucleotides in living organisms, moreover, it may serve as the biological carrier for some metal ions. cis-Diammine(orotato)platinum(II), cis-[Pt(C5H2N2O4)(NH3)2] can be considered as a new potential cisplatin analogue. The FT-Raman and FT-IR spectra of the title complex are reported, for the first time. The molecular structure, vibrational frequencies, and the theoretical infrared and Raman intensities have been calculated by the density functional mPW1PW91 method. The detailed vibrational assignment has been made on the basis of the calculated potential energy distribution. The theoretically predicted IR and Raman spectra show very good agreement with experiment. Natural bond orbital (NBO) analyses were performed for cisplatin, carboplatin and the title complex. The results provided new data on the nature of platinum–ligand bonding in these compounds. Strong intramolecular hydrogen bond between the orotate ligand and the coordinated ammonia group stabilizes the structure of the platinum(II) complex. Thus, it is suggested that the orotate ligand in the title complex is more inert to the substitution reactions than the chloride ligands in cisplatin. 相似文献
39.
40.
Tomasz Stawski Janusz Szklarzewicz Krzysztof Lewiński 《Transition Metal Chemistry》2006,31(3):353-361
The single crystal X-ray structure of (AsPh4)[W(bpy)(CN)6] is described. The structure of octa- and hepta-coordinated intermediates of substitutional photolysis of [Mo(CN)8]4− ion in aqueous media were determined by performing semi-empirical calculations. On the basis of obtained results as well
as on empirical data the photolysis scheme has been postulated. 相似文献