全文获取类型
收费全文 | 24019篇 |
免费 | 58篇 |
国内免费 | 45篇 |
专业分类
化学 | 10092篇 |
晶体学 | 406篇 |
力学 | 944篇 |
综合类 | 11篇 |
数学 | 3492篇 |
物理学 | 9177篇 |
出版年
2024年 | 3篇 |
2023年 | 17篇 |
2022年 | 180篇 |
2021年 | 369篇 |
2020年 | 379篇 |
2019年 | 550篇 |
2018年 | 1007篇 |
2017年 | 1114篇 |
2016年 | 1328篇 |
2015年 | 535篇 |
2014年 | 1105篇 |
2013年 | 1671篇 |
2012年 | 1507篇 |
2011年 | 1562篇 |
2010年 | 1776篇 |
2009年 | 1721篇 |
2008年 | 1691篇 |
2007年 | 1624篇 |
2006年 | 1417篇 |
2005年 | 881篇 |
2004年 | 616篇 |
2003年 | 323篇 |
2002年 | 315篇 |
2001年 | 305篇 |
2000年 | 609篇 |
1999年 | 347篇 |
1998年 | 446篇 |
1997年 | 425篇 |
1996年 | 108篇 |
1995年 | 31篇 |
1994年 | 27篇 |
1993年 | 4篇 |
1992年 | 11篇 |
1991年 | 9篇 |
1990年 | 14篇 |
1989年 | 5篇 |
1988年 | 6篇 |
1987年 | 9篇 |
1986年 | 6篇 |
1984年 | 3篇 |
1983年 | 8篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1974年 | 3篇 |
1971年 | 4篇 |
1968年 | 10篇 |
1875年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
E. A. Ekimov E. L. Gromnitskaya D. A. Mazalov A. F. Pal’ V. V. Pichugin S. Gierlotka B. Palosz J. A. Kozubowski 《Physics of the Solid State》2004,46(4):755-757
Superhard nanodiamond-SiC ceramics are prepared by infiltrating liquid Si into porous nanodiamond compacts under pressure.
Synthesized samples are 2.2 mm thick and 3–4 mm in diameter. The effect of particle size of dynamically synthesized nanodiamond
powders on silicon infiltration and SiC phase formation is studied. It is established that silicon does not penetrate into
the pores of nanodiamond powders if the original particle size is smaller than 0.5–1.0 μm. The critical pore size for infiltration
is 100–200 nm. A study of the microstructure of the samples showed the presence of the nanometer-and submicron-scale SiC phase.
The ultrasound velocities are measured in the prepared compacts, and the elastic moduli are calculated.
__________
Translated from Fizika Tverdogo Tela, Vol. 46, No. 4, 2004, pp. 734–736.
Original Russian Text Copyright ? 2004 by Ekimov, Gromnitskaya, Mazalov, Pal’, Pichugin, Gierlotka, Palosz, Kozubowski. 相似文献
32.
L. M. Vasilyak M. N. Vasil’ev S. P. Vetchinin D. N. Polyakov V. E. Fortov 《Journal of Experimental and Theoretical Physics》2003,96(3):440-443
The action of an electron beam on ordered dust structures in glow and low-pressure RF discharges was studied experimentally. The electron beam produces destruction and dynamic displacement of the dust structure. In the center of a dust structure, an electron beam with a low electron energy (tens of eV) at currents up to 1 mA caused structural disordering and “melting” in the region of its action but did not excite external crystal regions. Local action of an electron beam with a high electron energy (25 keV) and a beam current above 10 mA caused deformation of the whole dust structure and shifted it in the horizontal direction so that it was carried away from the RF discharge zone. The effect of dust structure displacements can be used to locally remove particles from a plasma. 相似文献
33.
We consider the application of asymptotic methods of nonlinear mechanics (the Krylov-Bogolyubov-Mitropol'skii method) and
the method of separation of motions in nonlinear systems for the construction of an approximate solution of a nonlinear equation
that describes a nonstationary wave process.
Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 50, No. 3, pp. 357–371, March, 1998. 相似文献
34.
Yu. A. Mitropol’skii Nguyen Dong Anh Nguyen Dyk Tynh 《Ukrainian Mathematical Journal》1998,50(11):1731-1737
We construct the second approximation for random oscillations described by the Van der Pol equation which are under the action
of a broadband random process.
Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 50, No. 11, pp. 1517–1521, November, 1998. 相似文献
35.
An expression for the probability of thermally activated tunneling ionization in an electric field in the presence of a magnetic
field is obtained. It is shown that the logarithm of the ionization probability is proportional to the squared electric field,
and the coefficient of proportionality decreases with increasing magnetic field.
Pis’ma Zh. éksp. Teor. Fiz. 68, No. 10, 763–767 (25 November 1998) 相似文献
36.
37.
E. D. Mishina N. É. Sherstyuk V. O. Val’dner A. V. Mishina K. A. Vorotilov V. A. Vasil’ev A. S. Sigov M. P. De Santo E. Cazzanelli R. Barberi Th. Rasing 《Physics of the Solid State》2006,48(6):1210-1213
Ferroelectric composite two-dimensional ferroelectric/aluminum oxide nanostructures were studied. A porous aluminum oxide matrix was used as a template into which a ferroelectric precursor was introduced, followed by annealing. The prepared nanostructures were studied using optical second harmonic generation and micro-Raman scattering. 相似文献
38.
A general method for solving the problem of quantization of a top is proposed that allows for finding the Hamiltonian eigenfunctions in the form of polynomials of various degree n in the Cartesian coordinates with the use of the Lamé functions. All three coordinates x, y, and z are equivalently involved in computations, as well as their relations with ellipsoidal coordinates, which makes the computations symmetric. 相似文献
39.
A. B. Vasil’eva A. A. Plotnikov 《Computational Mathematics and Mathematical Physics》2006,46(5):762-767
A singularly perturbed parabolic equation with a nonlinear right-hand side of a special form is examined. A numerical analytical study of such equations is performed. 相似文献
40.
V. V. Lozhkarev S. G. Garanin R. R. Gerke V. N. Ginzburg E. V. Katin A. V. Kirsanov G. A. Luchinin A. N. Mal’shakov M. A. Mart’yanov O. V. Palashov A. K. Poteomkin N. N. Rukavishnikov A. M. Sergeev S. A. Sukharev G. I. Freidman E. A. Khazanov A. V. Charukhchev A. A. Shaikin I. V. Yakovlev 《JETP Letters》2005,82(4):178-180
In experiments on the parametrical amplification of femtosecond pulses in wide-aperture DKDP crystals, a power of more than 100 TW has been reached, which is much higher than the record level achieved in such lasers. The energy efficiency obtained for the parametric amplifier is equal to 27%. The energy of a 72-fs pulse is equal to 10 J. 相似文献