全文获取类型
收费全文 | 333258篇 |
免费 | 6165篇 |
国内免费 | 4902篇 |
专业分类
化学 | 157126篇 |
晶体学 | 4592篇 |
力学 | 20310篇 |
综合类 | 329篇 |
数学 | 53111篇 |
物理学 | 108857篇 |
出版年
2022年 | 2664篇 |
2021年 | 3535篇 |
2020年 | 3815篇 |
2019年 | 4376篇 |
2018年 | 12415篇 |
2017年 | 12863篇 |
2016年 | 10101篇 |
2015年 | 4562篇 |
2014年 | 6593篇 |
2013年 | 11202篇 |
2012年 | 13332篇 |
2011年 | 21168篇 |
2010年 | 14547篇 |
2009年 | 14895篇 |
2008年 | 18600篇 |
2007年 | 21291篇 |
2006年 | 8817篇 |
2005年 | 12425篇 |
2004年 | 9587篇 |
2003年 | 9335篇 |
2002年 | 7963篇 |
2001年 | 7111篇 |
2000年 | 5558篇 |
1999年 | 4182篇 |
1998年 | 3859篇 |
1997年 | 3519篇 |
1996年 | 3459篇 |
1995年 | 3023篇 |
1994年 | 3008篇 |
1993年 | 2978篇 |
1992年 | 2960篇 |
1991年 | 3283篇 |
1990年 | 3190篇 |
1989年 | 3201篇 |
1988年 | 2988篇 |
1987年 | 2996篇 |
1986年 | 2799篇 |
1985年 | 3348篇 |
1984年 | 3402篇 |
1983年 | 2970篇 |
1982年 | 2998篇 |
1981年 | 2828篇 |
1979年 | 3031篇 |
1978年 | 3181篇 |
1977年 | 3179篇 |
1976年 | 3397篇 |
1975年 | 3087篇 |
1974年 | 3048篇 |
1973年 | 3266篇 |
1972年 | 2665篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
L. Resse L.G.S. Oliveira C.I.L. de Araujo A.R. Pereira R.L. Silva 《Physics letters. A》2019,383(14):1655-1659
In this work, we have used the MuMax3 software to simulate devices consisting of a ferromagnetic thin film placed over a heavy metal thin film. The devices are two interconnected partial-disks where a Néel domain wall is formed in the disks junction. In our simulations we investigate devices with disk radius nm and different distance d between the disks centers (from nm to nm). By applying strong sinusoidal external magnetic fields, we find a mechanism able to create, annihilate and even manipulate a skyrmion in each side of the device. This mechanism is discussed in terms of interactions between skyrmion and domain wall. The Néel domain wall formed in the center of the device interacts with the Néel skyrmion, leading to a process of transporting a skyrmion from one disk to the other periodically. Our results have relevance for potential applications in spintronics such as logical devices. 相似文献
4.
5.
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
6.
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
7.
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
8.
Yu. A. Sharin 《Russian Physics Journal》1998,41(5):447-450
Ideas previously enunciated by the author about the physical interpretation of curvilinear space with torsion are developed.
With the new equations describing the eigenstates of such a space, the static centrosymmetric solution for gravitational and
electric fields can be made consistent with the Newton and Coulomb laws. The asymptotic behavior of the axisymmetric solution
at infinity is studied. The gyromagnetic ratio obtained is characteristic of the electron.
Ural State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, p. 56–60, May, 1998. 相似文献
9.
10.
在氢化丁苯共聚物13C-NMR谱脂肪碳部分谱带归属的基础上,根据各谱带的主要来源,推导出六个二单元浓度的计算公式。计算出二单元、一单元的相对含量,各结构单元的数均序列长度、嵌段含量和其它结构参数。加氢前后的1H-和13C-NMR谱的组成计算结果基本一致。初步探讨了作为粘度指数改进剂的氢化丁苯共聚物微观结构与性能的关系,为合成提供了依据。 相似文献