全文获取类型
收费全文 | 142235篇 |
免费 | 393篇 |
国内免费 | 164篇 |
专业分类
化学 | 53947篇 |
晶体学 | 2239篇 |
力学 | 8987篇 |
综合类 | 2篇 |
数学 | 29011篇 |
物理学 | 48606篇 |
出版年
2021年 | 339篇 |
2019年 | 314篇 |
2018年 | 9987篇 |
2017年 | 10908篇 |
2016年 | 5051篇 |
2015年 | 1346篇 |
2014年 | 839篇 |
2013年 | 1703篇 |
2012年 | 6091篇 |
2011年 | 15194篇 |
2010年 | 9020篇 |
2009年 | 9131篇 |
2008年 | 12930篇 |
2007年 | 16712篇 |
2006年 | 1594篇 |
2005年 | 8573篇 |
2004年 | 4852篇 |
2003年 | 4688篇 |
2002年 | 2480篇 |
2001年 | 1522篇 |
2000年 | 1308篇 |
1999年 | 846篇 |
1998年 | 657篇 |
1997年 | 601篇 |
1996年 | 701篇 |
1995年 | 580篇 |
1994年 | 537篇 |
1993年 | 475篇 |
1992年 | 537篇 |
1991年 | 549篇 |
1990年 | 538篇 |
1989年 | 509篇 |
1988年 | 542篇 |
1987年 | 523篇 |
1986年 | 459篇 |
1985年 | 535篇 |
1984年 | 583篇 |
1983年 | 443篇 |
1982年 | 483篇 |
1981年 | 473篇 |
1980年 | 415篇 |
1979年 | 515篇 |
1978年 | 499篇 |
1977年 | 428篇 |
1976年 | 462篇 |
1975年 | 398篇 |
1974年 | 375篇 |
1973年 | 436篇 |
1972年 | 318篇 |
1968年 | 370篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
A. N. Bandura V. V. Chebotarev I. E. Garkusha V. A. Makhlay A. K. Marchenko D. G. Solyakov V. I. Tereshin S. A. Trubchaninov A. V. Tsarenko I. Landman 《Czechoslovak Journal of Physics》2004,54(3):C53
The paper presents experimental investigation of energy characteristics of the plasma streams generated with quasi—steady—state plasma accelerator QSPA Kh-50 and adjustment of plasma paramenters from the point of view its applicability for simulation of transient plasma heat loads expected for ITER disruptions and type I ELMs. Possibility of generation of high-power magnetized plasma streams with ion impact energy up to 0.6 keV, pulse length 0.25 ms and heat loads varied in wide range from 0.5 to 30 MJ/m2 has been demonstrated and some features of plasma interaction with tungsten targets in dependence on plasma heat loads are discussed. 相似文献
52.
X-ray diffraction patterns of nanocrystalline Fe-Cu-Nb-Si-B (FINEMET) alloys reveal that bcc α-Fe/α-FeSi crystallites with
the average grain size of 20(5) nm are dispersed in amorphous matrix. Enhanced electron—electron interaction (EEI) and quantum
interference (QI) effects as well as electron-magnon (and/or electron-spin fluctuation) scattering turn out to be the main
mechanisms that govern the temperature dependence of resistivity. Of all the inelastic scattering processes, inelastic electron-phonon
scattering is the most effective mechanism to destroy phase coherence of electron wave functions. The diffusion constant,
density of states at the Fermi level and the inelastic scattering time have been estimated, for the first time, for the alloys
in question
Article presented at the International Symposium on Advances in Superconductivity and Magnetism: Materials, Mechanisms and
Devices, ASMM2D-2001, 25–28 September 2001, Mangalore, India. 相似文献
53.
We propose to use the radiofrequency single-electron transistor as an extremely sensitive probe to detect the time-periodic ac signal generated by a sliding electron lattice in the insulating state of the two-dimensional electron gas. We also propose to use the optically-pumped NMR technique to probe the electron spin structure of the insulating state. We show that the electron effective mass and spin susceptibility are strongly enhanced by critical fluctuations of the electron lattice in the vicinity of the metal-insulator transition, as observed in experiment. 相似文献
54.
55.
I. V. Denisova O. A. Ladyzhenskaya G. A. Seregin N. N. Uraltseva E. V. Frolova 《Journal of Mathematical Sciences》2005,130(4):4775-4779
Bibliography: 42 titles.__________Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 306, 2003, pp. 7–15. 相似文献
56.
V. V. Kozlov 《Functional Analysis and Its Applications》2005,39(4):271-283
We discuss the symplectic geometry of linear Hamiltonian systems with nondegenerate Hamiltonians. These systems can be reduced to linear second-order differential equations characteristic of linear oscillation theory. This reduction is related to the problem on the signatures of restrictions of quadratic forms to Lagrangian planes. We study vortex symplectic planes invariant with respect to linear Hamiltonian systems. These planes are determined by the solutions of quadratic matrix equations of a special form. New conditions for gyroscopic stabilization are found. 相似文献
57.
Dimitar I. Pushkarov 《Central European Journal of Physics》2004,2(3):420-455
Basic ideas and results which characterize quantum diffusion of defects in quantum crystals like solid helium as a new phenomenon
are presented. Quantum effects in such media lead to a delocalization of point defects (vacancies, impurities etc.) and they
turn into quasiparticles of a new type—defectons, which are characterized not by their position in the crystal lattice but
by their quasimomentum and dispersion law. Defecton-defecton and defecton-phonon scattering are considered and an interpolation
formula for the diffusion coefficient valid in all interesting temperature and concentration regions is presented. A comparison
with the experimental data is made. Some alternative points of view are discussed in detail and the inconsistency of the Kisvarsanyi-Sullivan
theory is shown. 相似文献
58.
59.
60.
D. N. Karimov E. A. Krivandina Z. I. Zhmurova B. P. Sobolev V. A. Bezhanov S. P. Chernov G. M. Shapochkin 《Crystallography Reports》2006,51(6):1009-1015
Crystalline materials that are transparent in the vacuum UV spectral region and currently used have been reviewed. Transmission of crystals of solid solutions with the fluorite structure Ca1?x R xF2+x (R = Sc, Y, La, Yb, Lu) in the UV and vacuum UV spectral regions has been investigated. It is shown that application of different methods of purification of fluorides from some impurities can significantly improve the optical quality of fluoride multicomponent crystals in the short-wavelength spectral region. 相似文献