全文获取类型
收费全文 | 7611篇 |
免费 | 233篇 |
专业分类
化学 | 4000篇 |
晶体学 | 46篇 |
力学 | 139篇 |
数学 | 1648篇 |
物理学 | 2011篇 |
出版年
2023年 | 60篇 |
2021年 | 98篇 |
2020年 | 114篇 |
2019年 | 93篇 |
2018年 | 163篇 |
2017年 | 178篇 |
2016年 | 407篇 |
2015年 | 267篇 |
2014年 | 297篇 |
2013年 | 678篇 |
2012年 | 363篇 |
2011年 | 470篇 |
2010年 | 276篇 |
2009年 | 233篇 |
2008年 | 233篇 |
2007年 | 182篇 |
2006年 | 135篇 |
2005年 | 83篇 |
2004年 | 97篇 |
2003年 | 107篇 |
2002年 | 117篇 |
2001年 | 104篇 |
2000年 | 86篇 |
1999年 | 93篇 |
1998年 | 95篇 |
1997年 | 94篇 |
1996年 | 88篇 |
1995年 | 85篇 |
1994年 | 74篇 |
1993年 | 74篇 |
1992年 | 71篇 |
1991年 | 71篇 |
1989年 | 61篇 |
1988年 | 69篇 |
1987年 | 72篇 |
1986年 | 70篇 |
1985年 | 94篇 |
1984年 | 86篇 |
1983年 | 76篇 |
1982年 | 70篇 |
1981年 | 72篇 |
1980年 | 87篇 |
1979年 | 76篇 |
1978年 | 83篇 |
1977年 | 87篇 |
1976年 | 64篇 |
1974年 | 70篇 |
1973年 | 75篇 |
1966年 | 64篇 |
1965年 | 66篇 |
排序方式: 共有7844条查询结果,搜索用时 0 毫秒
31.
Dragan DJURCIC Aleksandar TORGASEV 《数学学报(英文版)》2006,22(3):689-692
In this paper, we prove some properties of the Seneta sequences and functions, and in particular we prove a representation theorem in the Karamata sense for the sequences from the Seneta class SOc. 相似文献
32.
Gašper Jaklič Jernej Kozak Marjeta Krajnc Vito Vitrih Emil Žagar 《Numerical Algorithms》2007,45(1-4):49-60
In this paper, three-pencil lattices on triangulations are studied. The explicit representation of a lattice, based upon barycentric
coordinates, enables us to construct lattice points in a simple and numerically stable way. Further, this representation carries
over to triangulations in a natural way. The construction is based upon group action of S
3 on triangle vertices, and it is shown that the number of degrees of freedom is equal to the number of vertices of the triangulation.
相似文献
33.
Abull is the (self-complementary) graph with verticesa, b, c, d, e and edgesab, ac, bc, bd, ce; a graphG is calledBerge if neitherG not its complement contains a chordless cycle whose length is odd and at least five. We prove that bull-free Berge graphs are perfect; a part of our argument relies on a new property of minimal imperfect graphs.This work was done while both authors were at the School of Computer Science, McGill University; support by NSERC is gratefully acknowledged. 相似文献
34.
A. Janušauskas 《Lithuanian Mathematical Journal》1996,36(1):22-31
Institute of Mathematics and Informatics. Akademijos 4, 2600 Vilnius, Lithuania. Translated from Lietuvos Matematikos Rinkinys.
Vol. 36, No. 1, pp. 27–38, January–March,. 1996. 相似文献
35.
The present paper summarizes detailed investigations of Nd3+ fluorescence spectra in YAP:Nd laser crystal in the broad spectral range of 370–1100 nm at liquid nitrogen temperature. Especially, Nd3+ near UV and visible fluorescence spectra were studied for the first time in this crystal. The Nd3+ near UV and visible fluorescence spectra of this crystal consist of many narrow lines (up to 50). The Nd3+ near UV and visible fluorescence lines arise mainly from4D3/2 and2P3/2 Nd3+ terms (transitions from4D3/2,2P3/2 to lower lying Nd3+ levels are responsible for their appearance). At room temperature the fluorescence spectra consist of broad bands with narrow lines (mainly4D3/24F3/2,4F5/2 and2H9/2 transitions). 相似文献
36.
Z. Kožíšek 《Czechoslovak Journal of Physics》1990,40(6):592-604
The kinetic equation of the classical homogeneous nucleation theory is rewritten in dimensionless form and it is shown that the numerical computation of the dimensionless kinetic equation is approximately 20 times faster in comparison with the original kinetic equation. The results are compared with known analytical results and with previous numerical results in the case of the constant and variable temperature for the model Li2O.2 SiO2 melt. It is shown, e.g., that under non-isothermal conditions the nucleation rate is greater than the quasistationary nucleation rate and the cluster distribution function is greater than the corresponding quasiequilibrium cluster distribution function. 相似文献
37.
XPS spectra of YIG, YIG:Bi, YIG:Ca and YIG:Co(Ge, Ca) epitaxial garnet films were measured at room temperature. The positions of the main iron, yttrium, oxygen, bismuth, cobalt and lead spectral lines were determined and their changes with the surface treatments were investigated. It was found that divalent and trivalent states of iron and cobalt ions can be resolved, the chemical shifts being in oposite directions.The authors would like to thank Dr. J. imová for careful EPMA analysis of the samples. 相似文献
38.
39.
K. Rohlena K. Mašek E. G. Balabanova I. Paulička 《Czechoslovak Journal of Physics》1988,38(6):622-637
Systematic calculations of maximum inversion were performed for iodine photodissociation laser in dependence on the mixture composition. The flash-lamp radiation was modelled as emanating from an optically thin Xe plasma. Duration of the pumping pulse is about 300 s. The sensitivity of the model to the values of kinetic constants was also tested. 相似文献
40.
We discuss productions of scalar gluonium candidates in the radiativeJ/ decays. The branching ratios of such productions are estimated on the basis of the Euler-Heisenberg effective Lagrangian for gluon-photon couplings. We mention that these estimates cannot be expected to be accurate to better than within a factor 2. We show that the radiativeJ/ decays probably invalidate gluoniumgg interpretation of the GAMS meson F0(1590) and a narrow 0++ stateS lying below 1 GeV. However, a possible wide scalar effective gluonium candidate(920) is shown not to be excluded by the data on the decayJ/. We also find that the experimental data about radiativeJ/ decays presumably agree with a recently suggested interpretation of F0(1590) as being approximately a half-and-half mixture of pure 0++ gluoniumgg andSU(3)f singlet quarkoniumq¯q states. 相似文献