全文获取类型
收费全文 | 7189篇 |
免费 | 328篇 |
国内免费 | 80篇 |
专业分类
化学 | 4282篇 |
晶体学 | 221篇 |
力学 | 194篇 |
综合类 | 4篇 |
数学 | 1044篇 |
物理学 | 1852篇 |
出版年
2022年 | 82篇 |
2021年 | 75篇 |
2020年 | 97篇 |
2019年 | 145篇 |
2018年 | 102篇 |
2017年 | 99篇 |
2016年 | 145篇 |
2015年 | 122篇 |
2014年 | 189篇 |
2013年 | 563篇 |
2012年 | 314篇 |
2011年 | 353篇 |
2010年 | 239篇 |
2009年 | 211篇 |
2008年 | 246篇 |
2007年 | 253篇 |
2006年 | 219篇 |
2005年 | 176篇 |
2004年 | 173篇 |
2003年 | 201篇 |
2002年 | 171篇 |
2001年 | 100篇 |
2000年 | 94篇 |
1999年 | 66篇 |
1997年 | 70篇 |
1996年 | 79篇 |
1995年 | 85篇 |
1994年 | 82篇 |
1993年 | 84篇 |
1992年 | 98篇 |
1991年 | 88篇 |
1990年 | 76篇 |
1989年 | 110篇 |
1988年 | 76篇 |
1987年 | 70篇 |
1986年 | 81篇 |
1985年 | 126篇 |
1984年 | 119篇 |
1983年 | 93篇 |
1982年 | 98篇 |
1981年 | 101篇 |
1980年 | 85篇 |
1979年 | 98篇 |
1978年 | 74篇 |
1977年 | 101篇 |
1976年 | 79篇 |
1975年 | 86篇 |
1974年 | 92篇 |
1973年 | 97篇 |
1972年 | 57篇 |
排序方式: 共有7597条查询结果,搜索用时 31 毫秒
951.
Bappanadu N. Rao 《Journal of Physics and Chemistry of Solids》1976,37(2):137-142
A two level two sublattice antiferromagnetic induced moment system is examined in the Green's function theory in the random phase approximation. Attentions are drawn to the effects of an externally applied magnetic field. It is shown that a “soft mode” behavior occurs at the transition field similar to that observed at the transition temperature in the absence of a field. The transition becomes first order in the RPA. The sublattice magnetizations and the transition field are significantly lowered compared to the molecular field theory results. 相似文献
952.
953.
954.
Various platinum complexes have been studied by 195Pt FT NMR. Long range J(31P195Pt) and J(195Pt195Pt) are observed in dinuclear complexes. The value of 1J(31P195Pt) in monomeric and dimeric complexes is shown to depend mainly upon the Pt—P bond length. 相似文献
955.
956.
Ferrites with the composition Mg1−x
CO
x
Fe2O4(0<x≤0·33) were synthesized by solid state reaction between MgO,α-Fe2O3 and CoFe2O4 at 1300°C. The compounds were analyzed from the results of x-ray diffraction, magnetic hysteresis and initial susceptibility
(χ) studies. All the compounds of the series were found to be monophasic with no appreciable change in their lattice parameter.
The saturation magnetization and coercive field (H
c
) values increased with increasing cobalt ferrite content. Similarly, the shapes of theχ-T curves and temperature variations ofH
c
values indicated that the magnetic behaviour changes from multi-domain to single domain with increasing cobalt content. The
results are similar to those observed for the (MgFe2O4)1−x
(Co3O4) system. 相似文献
957.
Hydrostatic pressure has negligible effect on the resistivity anomaly and thec
H
/a
H
ratio of Ti2O3. The results are consistent with the band-crossing mechanism wherein the a
T
and e
T
bands cross as thec
H
/a
H
ratio increases. 相似文献
958.
The article describes a new method for obtaining a holographic image of desired magnification, consistent with the stipulated criteria for its resolution and aberrations. 相似文献
959.
The feasibility of using homogeneous membrane-type halide ion-selective electrodes in solutions containing cationic surfactant compounds was examined. The results established the applicability of these electrodes for monitoring halide ions in solution without interference by the surfactants. The data also provided a basis for estimation of the surfactant in solution through the halide content. Two typical plating-bath compositions containing CTAB have been successfully analysed for their surfactant content by this procedure. 相似文献
960.