全文获取类型
收费全文 | 124166篇 |
免费 | 10008篇 |
国内免费 | 7252篇 |
专业分类
化学 | 72807篇 |
晶体学 | 1578篇 |
力学 | 7414篇 |
综合类 | 532篇 |
数学 | 15126篇 |
物理学 | 43969篇 |
出版年
2023年 | 1250篇 |
2022年 | 2673篇 |
2021年 | 3000篇 |
2020年 | 3279篇 |
2019年 | 3421篇 |
2018年 | 3756篇 |
2017年 | 3659篇 |
2016年 | 4717篇 |
2015年 | 3596篇 |
2014年 | 4873篇 |
2013年 | 6818篇 |
2012年 | 7285篇 |
2011年 | 7611篇 |
2010年 | 5758篇 |
2009年 | 5732篇 |
2008年 | 6064篇 |
2007年 | 5549篇 |
2006年 | 5083篇 |
2005年 | 4451篇 |
2004年 | 3855篇 |
2003年 | 3363篇 |
2002年 | 3411篇 |
2001年 | 3039篇 |
2000年 | 2472篇 |
1999年 | 2190篇 |
1998年 | 2042篇 |
1997年 | 1824篇 |
1996年 | 1760篇 |
1995年 | 1524篇 |
1994年 | 1523篇 |
1993年 | 1413篇 |
1992年 | 1326篇 |
1991年 | 1352篇 |
1990年 | 1339篇 |
1989年 | 1218篇 |
1988年 | 1059篇 |
1987年 | 1026篇 |
1986年 | 965篇 |
1985年 | 1013篇 |
1984年 | 973篇 |
1983年 | 872篇 |
1982年 | 850篇 |
1979年 | 805篇 |
1978年 | 812篇 |
1977年 | 806篇 |
1976年 | 920篇 |
1975年 | 812篇 |
1974年 | 844篇 |
1973年 | 847篇 |
1972年 | 752篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
931.
932.
933.
Yu. V. Pyatkov V. V. Pashkevich W. H. Trzaska G. G. Adamian N. V. Antonenko D. V. Kamanin V. A. Maslov V. G. Tishchenko A. V. Unzhakova 《Physics of Atomic Nuclei》2004,67(9):1726-1730
An analysis of the preferable fission path manifesting itself as a fine structure of the total kinetic energy-mass distribution of the fission fragments compelled us to put forward an absolutely new shape of the fissioning system on the descent from the fission barrier. It is a multicomponent nuclear molecule constituted by two magic clusters and a torus-like neck between. 相似文献
934.
A. N. Aleev N. S. Amaglobeli V. P. Balandin O. V. Bulekov I. M. Geshkov T. S. Grigalashvili E. A. Goudzovski D. K. Guriev D. D. Emelianov S. V. Eremin A. I. Zinchenko Z. M. Ivanchenko I. M. Ivanchenko M. N. Kapishin A. A. Loktionov V. D. Kekelidze Z. I. Kozhenkova V. V. Korenkov I. G. Kosarev N. A. Kuzmin A. L. Ljubimov D. T. Madigozhin V. G. Maznyj A. S. Mestvirishvili N. A. Molokanova A. N. Morozov R. E. Pismenyj V. D. Poze I. A. Polenkevich A. K. Ponosov T. Ponta Yu. K. Potrebenikov F. M. Sergeev L. A. Slepets V. N. Spaskov 《Physics of Atomic Nuclei》2004,67(8):1513-1522
The features of the associated production of φ mesons with Λ0 hyperons in neutron-carbon interactions were investigated. The experiment was performed with the aid of the EXCHARM spectrometer at the Serpukhov accelerator in a neutron beam of energy in the interval 20–70 GeV. The differential cross section for inclusive associated φΛ0 production was measured. 相似文献
935.
V. K. Voronkova R. T. Galeev S. Shova G. Novitchi C. I. Turta A. Caneschi D. Gatteschi J. Lipkowski Yu. A. Simonov 《Applied magnetic resonance》2003,25(2):227-247
New compounds, [Cu3Ln2(ClCH2COO)12(H2O)8]·2H2O with Ln = Nd3+ (I), Sm3+ (II), Pr3+ (III), built up of pentanuclear clusters were synthesized and studied by means of X-ray analysis and electron paramagnetic
resonance (EPR). X-ray data show that all compounds are isostructural and the pentanuclear clusteres may be considered as
a linear system with alternating Cu(II) and Ln(III) ions: Cu(2)-L1-Ln-L2-Cu(1)-L2-Ln-L2-Cu(2) with L1 and L2 being bridging fragments and Cu(1) and Cu(2) being structurally nonequivalent copper complexes. EPR studies demonstrate that
in the temperature range of 100–293 K the signals due to only one type of the copper complexes are observed in the spectra
of I–III. AtT<100 K the spectral temperature dependence is nontrivial. AtT<30 K new signals are detected in the spectra of I and II. The temperature dependence of the EPR spectra is interpreted under
the assumption that the parameter of the exchange interaction Cu(2)-Ln considerably exceeds the parameter of the interaction
Cu(1)-Ln. EPR spectra are calculated for the fragments of five paramagnetic centers in the frames of the model taking into
account the nonequivalence of two copper complexes, short longitudinal and transverse paramagnetic relaxation times of the
rare-earth ions at room temperature and the change of the relaxation rates when the temperature decreases. The results of
the calculations show that it is possible to obtain information about the interactions in the system on the basis of the analysis
of the temperature dependence of the EPR spectra of the central copper complex. The parameter of the isotropic part of the
exchange interaction between copper and neodymium ions (for the interaction Cu(2)-Nd) is estimated as about 15 cm−1. A considerable rearrangement of the spin states when the temperature changes is found for all complexes. 相似文献
936.
The classes ofL
1-matrices,L
2-matrices,L
3-matrices andW-matrices are introduced to study solvability of a linear complementarity problem via solving a linear program. Three sufficient
conditions are presented to guarantee that a linear complementarity problem is solvable via a linear program. The new sufficient
conditions are weaker than the ones introduced by Mangasarian. This fact is also illustrated by an example.
Partially supported by NSFC.
This author is also with College of Business Administration of Human University as a Lotus chair professor. 相似文献
937.
Tsarev Yu. V. Dmitriev A. E. Kostrov V. V. 《Russian Journal of Applied Chemistry》2003,76(11):1772-1775
Stages of synthesis of a copper-containing catalyst for electrocatalytic oxidation of acetone in waste gases were studied. The course of the extrusion and calcination and their influence on electrocatalytic oxidation of acetone on the catalyst synthesized were analyzed. 相似文献
938.
The influence of the sequence of Cu and Pd introduction into zeolite matrice when preparing Cu, Pd-zeolite catalysts on their acidity and degree of metal reduction was studied. The mutual influence of Cu and Pd on their reducibility was analyzed. The selectivity of Cu, Pd-zeolite catalysts in conversion of synthesis gas to different products was elucidated. 相似文献
939.
940.