全文获取类型
收费全文 | 8668篇 |
免费 | 186篇 |
国内免费 | 170篇 |
专业分类
化学 | 804篇 |
晶体学 | 86篇 |
力学 | 85篇 |
综合类 | 25篇 |
数学 | 6735篇 |
物理学 | 1289篇 |
出版年
2023年 | 21篇 |
2022年 | 59篇 |
2021年 | 96篇 |
2020年 | 53篇 |
2019年 | 189篇 |
2018年 | 184篇 |
2017年 | 114篇 |
2016年 | 70篇 |
2015年 | 79篇 |
2014年 | 178篇 |
2013年 | 483篇 |
2012年 | 272篇 |
2011年 | 435篇 |
2010年 | 390篇 |
2009年 | 545篇 |
2008年 | 587篇 |
2007年 | 613篇 |
2006年 | 549篇 |
2005年 | 430篇 |
2004年 | 357篇 |
2003年 | 266篇 |
2002年 | 250篇 |
2001年 | 197篇 |
2000年 | 192篇 |
1999年 | 225篇 |
1998年 | 178篇 |
1997年 | 162篇 |
1996年 | 217篇 |
1995年 | 182篇 |
1994年 | 198篇 |
1993年 | 134篇 |
1992年 | 115篇 |
1991年 | 99篇 |
1990年 | 59篇 |
1989年 | 81篇 |
1988年 | 60篇 |
1987年 | 64篇 |
1986年 | 58篇 |
1985年 | 97篇 |
1984年 | 61篇 |
1983年 | 55篇 |
1982年 | 65篇 |
1981年 | 51篇 |
1980年 | 57篇 |
1979年 | 30篇 |
1978年 | 38篇 |
1977年 | 34篇 |
1976年 | 43篇 |
1974年 | 16篇 |
1973年 | 15篇 |
排序方式: 共有9024条查询结果,搜索用时 203 毫秒
111.
B. Sahoo W. Keune E. Schuster W. Sturhahn T. S. Toellner E. E. Alp 《Hyperfine Interactions》2006,168(1-3):1185-1190
Amorphous (a-) Fe x Mg1?x alloys are interesting materials for the investigation of non-Debye-like low-energy vibrational excitations. We have prepared a-Fe x Mg1?x alloy thin films (0.3 ≤ × ≤0.7) by vapour quenching. The amorphous state was confirmed by conversion electron Mössbauer spectroscopy between 4.2–300 K, and the x- and temperature-dependence of the isomer shift and hyperfine magnetic field was measured. For x= 0.6 and 0.7, magnetic ordering occurs below ~150 K. The atomic vibrational density of states, g(E), was determined by nuclear resonant inelastic scattering, providing clear evidence for the non-Debye-like low-energy vibrational excitations. 相似文献
112.
113.
Bruno Zimmermann 《Monatshefte für Mathematik》2002,135(3):253-258
We give a list including all finite groups G which admit smooth orientation preserving actions on homology 3-spheres (arbitrary actions, i.e. possibly with fixed points;
if the action is free then the group G has periodic cohomology and the classification of such groups is well known). The main work in this direction is due to M.
Reni. In the present paper, we complete and extend his results for the case of nonsolvable groups G.
Received 19 March 2001; in revised form 15 September 2001 相似文献
114.
Heavy ion irradiation in the electronic stopping power region induces macroscopic dimensional change in metallic glasses and introduces magnetic anisotropy in some magnetic materials. The present work is on the irradiation study of ferromagnetic metallic glasses, where both dimensional change and modification of magnetic anisotropy are expected. Magnetic anisotropy was measured using Mössbauer spectroscopy of virgin and irradiated Fe40Ni40B20 and Fe40Ni38Mo4B18 metallic glass ribbons. 90 MeV 127I beam was used for the irradiations. Irradiation doses were 5×1013 and 7.5×1013 ions/cm2. The relative intensity ratios D 23 of the second and third lines of the Mössbauer spectra were measured to determine the magnetic anisotropy. The virgin samples of both the materials display in-plane magnetic anisotropy, i.e., the spins are oriented parallel to the ribbon plane. Irradiation is found to cause reduction in magnetic anisotropy. Near-complete randomization of magnetic moments is observed at high irradiation doses. Correlation is found between the residual stresses introduced by ion irradiation and the change in magnetic anisotropy. 相似文献
115.
Yuval Z. Flicker 《Mathematische Annalen》1993,297(1):199-219
116.
We give cogenerators for the categories of convex (= finitely superconvex), finitely positively convex, and absolute convex (= finitely totally convex) spaces introduced by Pumplün and Röhrl.Dedicated to our academic teacher Dieter Pumplün on the occasion of his sixtieth birthday. 相似文献
117.
The general centered form for multi-variate polynomials is investigated and a computing procedure is proposed that results in a certain superset. Based on this procedure the optimal centered forms for monomials and for some special cases of polynomials are investigated. 相似文献
118.
Akihiko Yukie 《Mathematische Annalen》1992,292(1):355-374
Partially supported by NSF Grant DMS-8803085, DMS-8610730 相似文献
119.
120.
We introduce a candidate for the group algebra of a Hausdorff group which plays the same role as the group algebra of a finite group. It allows to define a natural bijection betweenk-continuous representations of the group in a Hilbert space and continuous representations of the group algebra. Such bijections are known, but to our knowledge only for locally compact groups. We can establish such a bijection for more general groups, namely Hausdorff groups, because we replace integration techniques by functorial methods, i.e., by using a duality functor which lives in certain categories of topological Banach balls (resp., unit balls of Saks spaces).This paper was written while the authors were supported by the Swiss National Science Foundation under grant 21-33644.92. 相似文献