全文获取类型
收费全文 | 552042篇 |
免费 | 3204篇 |
国内免费 | 925篇 |
专业分类
化学 | 258047篇 |
晶体学 | 8273篇 |
力学 | 30838篇 |
综合类 | 11篇 |
数学 | 84368篇 |
物理学 | 174634篇 |
出版年
2020年 | 4670篇 |
2019年 | 5459篇 |
2018年 | 12718篇 |
2017年 | 13150篇 |
2016年 | 13042篇 |
2015年 | 5769篇 |
2014年 | 9727篇 |
2013年 | 20292篇 |
2012年 | 18554篇 |
2011年 | 26319篇 |
2010年 | 18869篇 |
2009年 | 18970篇 |
2008年 | 24288篇 |
2007年 | 26361篇 |
2006年 | 16655篇 |
2005年 | 17669篇 |
2004年 | 15337篇 |
2003年 | 14665篇 |
2002年 | 13740篇 |
2001年 | 13173篇 |
2000年 | 10607篇 |
1999年 | 7866篇 |
1998年 | 7200篇 |
1997年 | 7068篇 |
1996年 | 6702篇 |
1995年 | 6018篇 |
1994年 | 6168篇 |
1993年 | 5894篇 |
1992年 | 6293篇 |
1991年 | 6615篇 |
1990年 | 6495篇 |
1989年 | 6403篇 |
1988年 | 6279篇 |
1987年 | 6244篇 |
1986年 | 5799篇 |
1985年 | 7324篇 |
1984年 | 7755篇 |
1983年 | 6583篇 |
1982年 | 6819篇 |
1981年 | 6522篇 |
1980年 | 6318篇 |
1979年 | 6680篇 |
1978年 | 7042篇 |
1977年 | 6972篇 |
1976年 | 7193篇 |
1975年 | 6657篇 |
1974年 | 6560篇 |
1973年 | 6865篇 |
1972年 | 5278篇 |
1971年 | 4584篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
V. A. Nebol'sin B. M. Darinskii E. E. Popova A. A. Shchetinin 《Russian Physics Journal》1995,38(10):1023-1026
An estimate of the factors which influence the rate of growth of filamentary silicon crystals in a standard chloride system using a quartz reactor with hot walls is given. It is shown that a diffusion form of crystallization is observed under the conditions investigated.Voronezh State Technical University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 22–26, October, 1995. 相似文献
52.
V. I. Storozhev 《Journal of Mathematical Sciences》1995,77(6):3514-3518
On the basis of the method of successive approximations in formal series we construct systems of particular solutions of the
equations of planar and flexural harmonic vibrations of thin rectilinear anisotropic plates with a plane of symmetry of elastic
properties parallel to the faces. The solutions constructed are classified as special sk-functions of generalized complex
variables.
Translated fromTeoreticheskaya i Prikladnaya Mekhanika No. 24, 1993, pp. 54–61. 相似文献
53.
F. G. Vagizov 《Hyperfine Interactions》1995,95(1):85-95
We present the results of an experimental investigation of a RF splitting of57Fe hyperfine lines in the regime of NMR and Mössbauer double resonance. The experiments have been performed as a function of RF field intensity and static magnetic field magnitude. The intensity of the RF components and the separation between them are extremely sensitive to the frequency and amplitude of the RF magnetic field. The RF splitting of hyperfine lines is inversely proportional to the strength of the static magnetic field. 相似文献
54.
The characterization of the clusters formed on alkaline hydrolysis of [PdCl4]2– was performed using17O,23Na,35Cl,133Cs NMR and UV spectroscopy. The chemical composition of the clusters was found to be [Pd(OH)2]
n
·nNaCl. No mononuclear oxo- or hydroxocomplexes were detected. The spatial structure of the clusters is stabilized by alkali metal cations.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 675–679, April, 1993. 相似文献
55.
The electrical conductivity of hydrosols of ultradispersed diamonds was studied. The electromembrane method for cleaning and concentrating of ultradispersed diamonds in hydrosols was considered. The influence exerted by the concentration of the dispersed phase on the electrical characteristics of the cleaning process was analyzed. A mathematical relation making it possible to evaluate the output characteristics of the process and to determine the geometrical characteristics of the apparatus was proposed. 相似文献
56.
A. E. Dorokhov 《Czechoslovak Journal of Physics》2002,52(3):C79-C90
Nonperturbative nolocal structure of QCD vacuum is well described by instanton model. Specific helicity and flavor structure of zero modes of quarks, in instanton field allows simultaneously to explain some important features of low-and high-energy hadron phenomemology. The basic characteristics of hadron spectrum, partonic sum rules, heavyquark potential etc within the instanton liquid model are briefly discussed. 相似文献
57.
The radiation emitted by charged, scalar particles in a Schwarzschild field with maximal acceleration corrections is calculated classically and in the tree approximation of quantum field theory. In both instances the particles emit radiation that has characteristics similar to those of gamma-ray bursters. 相似文献
58.
V. Palyok I.A. Szabó D.L. Beke A. Kikineshi 《Applied Physics A: Materials Science & Processing》2002,74(5):683-687
Surface relief formation at holographic recording on amorphous selenium films was demonstrated and investigated. The presence
of this optical phase modulation component is essential for ensuring significant, stable and erasable optical recording in
a-Se films at 290–320 K temperatures, where conventional photodarkening was known as insignificant and unstable. Photocrystallization
can only be observed in super-exposed a-Se films at the given experimental conditions of hologram recording. Erasing behavior
of surface relief gratings under heat treatment was also investigated in order to reveal further details of the mechanism.
Photoinduced structural transformations within the amorphous phase, connected to local ordering under the condition of light-induced
fluidity, are proposed as an explanation for the relief formation and erasing. The observed reversible optical recording process
may be useful for the various optoelectronic applications of photoconductive a-Se layers.
Received: 12 June 2000 / Accepted: 6 June 2001 / Published online: 30 August 2001 相似文献
59.
D. V. Vyalykh A. M. Shikin G. V. Prudnikova A. Yu. Grigor’ev A. G. Starodubov V. K. Adamchuk 《Physics of the Solid State》2002,44(1):164-170
This paper reports on the first experimental observation of quantum-well states and sp-type resonances in thin single-crystal gold, silver, and copper layers formed on single-crystal W(110) surfaces, which result from spatial localization of Bloch-type electronic wave functions in a quantum well with potential barriers at the vacuum/metal and metal/W(110) interfaces. The quantization of the valence-band electronic structure in Au/W(110), Ag/W(110), and Cu/W(110) systems was studied experimentally using angle-resolved photoelectron spectroscopy. 相似文献
60.
Yu. V. Borovskikh 《Journal of Mathematical Sciences》1991,53(4):353-358
Estimates of a rate of convergence of orderO(n
–1) are obtained for integral functionals of an empirical process.Translated fromTeoriya Sluchainykh Protsessov, Vol. 15, pp. 10–16, 1987. 相似文献