全文获取类型
收费全文 | 486篇 |
免费 | 9篇 |
国内免费 | 3篇 |
专业分类
化学 | 310篇 |
晶体学 | 2篇 |
力学 | 11篇 |
数学 | 86篇 |
物理学 | 89篇 |
出版年
2023年 | 3篇 |
2022年 | 13篇 |
2021年 | 16篇 |
2020年 | 9篇 |
2019年 | 19篇 |
2018年 | 12篇 |
2017年 | 10篇 |
2016年 | 9篇 |
2015年 | 14篇 |
2014年 | 18篇 |
2013年 | 35篇 |
2012年 | 22篇 |
2011年 | 41篇 |
2010年 | 24篇 |
2009年 | 18篇 |
2008年 | 18篇 |
2007年 | 21篇 |
2006年 | 27篇 |
2005年 | 26篇 |
2004年 | 13篇 |
2003年 | 11篇 |
2002年 | 5篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 7篇 |
1995年 | 4篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1985年 | 10篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 10篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 5篇 |
1976年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1959年 | 1篇 |
排序方式: 共有498条查询结果,搜索用时 31 毫秒
51.
Aleksander Yevtushenko Michal Kuciej Olena Yevtushenko 《Archive of Applied Mechanics (Ingenieur Archiv)》2011,81(6):715-726
The transient temperature field and corresponding quasi-static thermal stresses are analysed in a system consisting of a semi-space
and a strip. The strip is heated on its outer surface by a heat flux with the intensity equal to the specific power of friction
during braking with a uniform retardation. The evolution and distribution in depth from a surface of friction for temperatures
and thermal stresses were investigated for the metal-ceramic FMK-11 material of the strip. 相似文献
52.
53.
Madhuri Mukhopadhyay Debi Banerjee Aleksander Koll Aleksander Filarowski Samaresh Mukherjee 《Chemical physics letters》2006,420(4-6):316-320
The effect of neutral, cationic and anionic micellar environments on the ground and excited state proton transfer reactions of salicylidine-3,4,7-methyl amine (SMA) in water has been studied by steady state and time resolved fluorescence spectroscopy. In the ground state, the formation of the primary form of SMA is enhanced at the expense of the zwitterionic species due to micellization. In the excited state, anion formation decreases both in the presence of Triton-X and cetyl trimethyl ammonium bromide (CTAB). However, in the presence of sodium dodecyl sulphate (SDS), the anionic emission increases after reaching a certain micellar concentration. The lifetime of the anion is significantly reduced in CTAB compared to that in the bulk water and also in the presence of Triton-X. It is proposed that the destabilization and modification of SMA anion occurs due to the different electrostatic environments produced by micellization. 相似文献
54.
B. P. Barkov O. N. Baloshin N. V. Batalova V. V. Vladimirskii V. K. Grigor’ev O. N. Erofeeva Yu. V. Katinov I. Ya. Korol’kov V. I. Lisin V. N. Luzin V. N. Nozdrachev V. V. Sokolovskii G. D. Tikhomirov S. A. Uzunyan Yu. P. Shkurenko 《JETP Letters》1998,68(10):764-769
The preliminary results of an investigation of a system of two K
S
mesons in the mass interval 1600–1950 MeV are reported. The events were obtained on a 6-m magnetic spark spectrometer at ITEP
in π −
p interactions at 40 GeV, using a neutral trigger which suppressed both charged particles and γ rays. A peak of width ≃30 MeV
with statistical significance not lower than six standard deviations is observed with momentum transfer selection |tu|0.23
GeV2 near the mass 1775 MeV of the K
S
K
S
system. The observed phenomena can be interpreted as the existence of one resonance with the indicated parameters, or two
narrower resonances. In the latter case, their masses are 1768±1.5 and 1787±1.5 MeV. The widths of these states are comparable
to the mass resolution of the spectrometer (∼5 MeV). Estimates of the product σ ⋅BR(K
S
K
S
) give ∼1.5 and 2.5 nb, respectively, for the first and second states.
Pis’ma Zh. éksp. Teor. Fiz. 68, No. 10, 727–731 (25 November 1998) 相似文献
55.
In the first part of the paper we give a construction of a topological degree theory for set-valued tangent vector fields with convex and nonconvex values defined on nonsmooth closed subsets of a Banach space. The obtained homotopy invariant is an extension of the classical degree for vector fields on manifolds. In the second part we propose a fixed-point index for inward maps on arbitrary closed convex sets. 相似文献
56.
57.
Aleksander Jablonski 《Surface science》1985,151(1):166-182
A Monte Carlo algorithm is proposed for calculating the elastic reflection coefficient, ηE, for elements. The algorithm accounts for the multiple elastic scattering of electrons in solids. The calculated values of ηE compare well with the literature data for elements with atomic number up to 47 and at primary energies above 2 keV. The proposed Monte Carlo method makes it possible to determine the functional relation between ηE and the inelastic mean free path, λ. This relation turned out to be non-linear, arid it deviates from a similar relation based on published earlier single elastic scattering model. The deviation is especially pronounced for elements with medium atomic numbers. The calculated function offers a convenient method for determining the inelastic mean free path. The values of λ derived in the present work from published experimental values of ηE compare very well with the literature data. 相似文献
58.
59.
60.
Aleksander Glikson 《Archive for Rational Mechanics and Analysis》1972,45(1):35-46
We consider a Boltzmann gas which fills all of space and is under the influence of a field of conservative external force whose potential is bounded from below.Assuming the intermolecular force has a cut-off, we prove existence and uniqueness for the general solution of the nonlinear Maxwell-Boltzmann equation at least in a finite interval of time. The solution can be constructed by the method of successive approximations in corresponding complete spaces. Definitions of these spaces are connected with an exponential function of the total energy of the molecule.Some indications of future generalizations and investigations are given. 相似文献