全文获取类型
收费全文 | 310551篇 |
免费 | 7273篇 |
国内免费 | 5358篇 |
专业分类
化学 | 152839篇 |
晶体学 | 4313篇 |
力学 | 17902篇 |
综合类 | 325篇 |
数学 | 56181篇 |
物理学 | 91622篇 |
出版年
2022年 | 2111篇 |
2021年 | 2893篇 |
2020年 | 3355篇 |
2019年 | 3603篇 |
2018年 | 14301篇 |
2017年 | 14059篇 |
2016年 | 11546篇 |
2015年 | 4594篇 |
2014年 | 5880篇 |
2013年 | 10898篇 |
2012年 | 13145篇 |
2011年 | 20992篇 |
2010年 | 13548篇 |
2009年 | 13927篇 |
2008年 | 16128篇 |
2007年 | 17753篇 |
2006年 | 9077篇 |
2005年 | 9242篇 |
2004年 | 8673篇 |
2003年 | 8478篇 |
2002年 | 7563篇 |
2001年 | 8103篇 |
2000年 | 6095篇 |
1999年 | 4691篇 |
1998年 | 3726篇 |
1997年 | 3564篇 |
1996年 | 3430篇 |
1995年 | 3005篇 |
1994年 | 3015篇 |
1993年 | 2777篇 |
1992年 | 3207篇 |
1991年 | 3337篇 |
1990年 | 3169篇 |
1989年 | 3054篇 |
1988年 | 2923篇 |
1987年 | 2936篇 |
1986年 | 2719篇 |
1985年 | 3207篇 |
1984年 | 3219篇 |
1983年 | 2656篇 |
1982年 | 2624篇 |
1981年 | 2389篇 |
1980年 | 2369篇 |
1979年 | 2758篇 |
1978年 | 2840篇 |
1977年 | 2759篇 |
1976年 | 2818篇 |
1975年 | 2600篇 |
1974年 | 2600篇 |
1973年 | 2627篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
161.
Lebedev V. T. Serebrov A. P. 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2020,14(1):1-5
Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques - A method for studying the magnetic dynamics of endofullerenes M@C2n (2n = 60, 70, …) and their derivatives,... 相似文献
162.
163.
164.
The structure, chemical composition, and magnetic properties of electrochemically deposited nanocrystalline Co-Ni-Fe films
were investigated using a number of techniques. A high saturation magnetic induction up to B
s
= 21 kG was attained. An enhancement of the saturation magnetization compared to the ideal anticipated one was revealed,
which correlated with the nonlinear behavior of the structural phase composition and lattice parameters with the change of
the composition.
The text was submitted by the authors in English. 相似文献
165.
The γcmc values of CTAB-SDS decrease from 63.67 mN/m at 10‡C to 36.38 mN/m at 90‡C, slightly lower than those of either CTAB or SDS.
Correspondingly, the CMC of CTAB-SDS decreases almost by half. The increase of surface activity of CTAB-SDS can be attributed
to the relatively weak electrostatic interaction at high temperature, which is supported by the increase of solubility of
CTAB-SDS with rise in temperature. Catalytic effect on oxidation of toluene derivatives with potassium permanganate follows
the order CTAB-SDS > SDS > CTAB. This is not caused by the dissociative effect of CTAB-SDS with low surface activity at low
temperature, as seen from the fact that almost all oxidative products can be retrieved for different toluene derivatives and
surfactants by mimicking the conditions of reaction. In the emulsifications of toluene derivatives at 90‡C, the time that
turbid water layers of surfactant solutions take to become clear is the same as that of the catalytic effect on oxidation
of toluene derivatives. Thus, it can be inferred that surfactants can improve the oxidation yields of toluene derivatives
by increasing the contact between two reacting phases. 相似文献
166.
Yu. V. Pokonova 《Russian Journal of Applied Chemistry》2007,80(12):2163-2164
Kinetic, sorption and selectivity properties of commercial adsorbents are improved by adding petroleum residues (tar asphaltene concentrates) 13% of whole mass. Obtained adsorbents can be used for selective extraction of nobel metals from multicomponent polymetallic solutions of heavy metals and fro sewages purification for removing arsenic. 相似文献
167.
168.
169.
T. Noiri 《Acta Mathematica Hungarica》1998,80(1-2):105-113
In this paper the notion of pre gs-closed functions is introduced and investigated. Presemiclosed functions are pre gs-closed but not conversely. It is shown that s-normality is preserved under continuous pre gs-closed surjections. 相似文献
170.
Experimental data on the effect of thallium and sodium impurities on the lattice heat conductivity of PbTe at room temperature
are reported. Because the lattice of lead chalcogenides is strongly polarized near charged impurities, the effect of impurities
on the lattice heat conductivity depends substantially on their charge state. This property of the material has been used
to determine the charge state of the thallium impurity in PbTe. The results obtained argue for a model of quasi-local thallium-impurity
states which assumes low electron-correlation energy at an impurity center.
Fiz. Tverd. Tela (St. Petersburg) 40, 1206–1208 (July 1998) 相似文献