全文获取类型
收费全文 | 486篇 |
免费 | 1篇 |
专业分类
化学 | 129篇 |
晶体学 | 5篇 |
力学 | 68篇 |
数学 | 46篇 |
物理学 | 239篇 |
出版年
2021年 | 4篇 |
2020年 | 10篇 |
2019年 | 8篇 |
2018年 | 12篇 |
2017年 | 12篇 |
2016年 | 19篇 |
2015年 | 3篇 |
2014年 | 23篇 |
2013年 | 21篇 |
2012年 | 20篇 |
2011年 | 17篇 |
2010年 | 23篇 |
2009年 | 22篇 |
2008年 | 23篇 |
2007年 | 19篇 |
2006年 | 23篇 |
2005年 | 21篇 |
2004年 | 16篇 |
2003年 | 16篇 |
2002年 | 13篇 |
2001年 | 14篇 |
2000年 | 16篇 |
1999年 | 9篇 |
1998年 | 12篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 8篇 |
1994年 | 7篇 |
1993年 | 12篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 8篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1969年 | 3篇 |
1968年 | 2篇 |
1966年 | 3篇 |
1917年 | 1篇 |
排序方式: 共有487条查询结果,搜索用时 0 毫秒
91.
92.
93.
94.
G. A. Andreeva N. S. Polyakov M. M. Dubinin K. M. Nikolaev E. A. Ustinov 《Russian Chemical Bulletin》1981,30(10):1791-1795
95.
The behavior of topological solitons in a parallel array of a Josephson junction is studied experimentally. We observe the fusion of two relativistic solitons of the same polarity into a single soliton. The soliton carries two quanta of magnetic flux and, most strikingly, travels 18% faster than an ordinary soliton under the same driving force. We also find a variety of bunched states composed of solitons of the same polarity, moving with fixed separation. 相似文献
96.
In the paper, the explicit form of distribution function for the lengths of arcs connecting neighbouring rational points on the unit circle whose denominators do not exceed given value, is given. 相似文献
97.
A new method is described for attaining high magnetoresistance in inhomogeneous magnetic materials, which makes use of the formation of a depleted layer and a contact potential difference at the interface separating two semiconductors with different Fermi levels and the magnetic-field-induced variation in the contact potential difference and thickness of the interface layer. The proposed model of the magnetoresistive structure is realized on the basis of the HgCr2Se4 magnetic semiconductor. Layers of n-HgCr2Se4 up to a few tens of microns thick were prepared on the surface of p-HgCr2Se4 bulk single crystals by the diffusion technique. Application of a magnetic field stimulated in the structures a strong (by a factor of more than 200) increase of the current flowing through the n-layer. 相似文献
98.
A Kirchhoff-Love type applied theory is used to study the specific characteristics of harmonic waves and vibrations of a helically
anisotropic shell. Special attention is paid to axisymmetric and bending vibrations. In both cases, the dispersion equations
are constructed and a qualitative and numerical analysis of their roots and the corresponding elementary solutions is performed.
It is shown that the skew anisotropy in the axisymmetric case generates a relation between the longitudinal and torsional
vibrations which is mathematically described by the amplitude coefficients of homogeneous waves. In the case of a shell with
rigidly fixed end surfaces, the dependence of the first two natural frequencies on the shell length and the helical line slope
α, i.e., the geometric parameter of helical anisotropy, is studied. A boundary value problem in which longitudinal vibrations
are generated on one of the end surfaces and the other end is free of forces and moments is considered to analyze the degree
of transformation of longitudinal vibrations into longitudinally torsional vibrations. In the case of bending vibrations,
two problems for a half-infinite shell are studied as well. In the first problem, the waves are excited kinematically by generating
harmonic vibrations of the shell end surface in the plane of the axial cross-section, and it is shown that the axis generally
moves in some closed trajectories far from the end surface. In the second problem, the reflection of a homogeneous wave incident
on the shell end is examined. It is shown that the “boundary resonance” phenomenon can arise in some cases. 相似文献
99.
I. V. Serkov A. N. Proshin A. K. Ustinov B. V. Lednev E. V. Fomina-Ageeva A. M. Ashba V. V. Bezuglov S. O. Bachurin 《Doklady Chemistry》2018,478(1):9-11
An approach to the synthesis of adamantane derivatives with NO-generating fragment containing nitroxy group has been developed. 1-Aminoadamantane, memantine, and adamantanecarboxylic acid have been used as initial compounds. The prepared compounds have shown ability to generate nitric oxide in a system mimicking biological reactions of nitro group reduction. 相似文献
100.
H. Mühe Mc. Candless E. Valenta Utz Wilh Vaubel B. Ahlström O. Aschan J. Kondakow J. Schindelmeiser R. Böhme H. Herzfeld J. E. Teeple R. Adan J. Marcusson Darmois H. Wolff C. Piest R. Marcille EA. Parry M. Adams H. W. Fosse K. Ihnatowzcz 《Analytical and bioanalytical chemistry》1917,56(10-11):541-560