全文获取类型
收费全文 | 1045篇 |
免费 | 15篇 |
专业分类
化学 | 331篇 |
晶体学 | 4篇 |
力学 | 90篇 |
数学 | 170篇 |
物理学 | 465篇 |
出版年
2022年 | 10篇 |
2021年 | 20篇 |
2020年 | 11篇 |
2019年 | 23篇 |
2018年 | 32篇 |
2017年 | 32篇 |
2016年 | 34篇 |
2015年 | 23篇 |
2014年 | 36篇 |
2013年 | 53篇 |
2012年 | 55篇 |
2011年 | 41篇 |
2010年 | 40篇 |
2009年 | 36篇 |
2008年 | 43篇 |
2007年 | 31篇 |
2006年 | 31篇 |
2005年 | 19篇 |
2004年 | 26篇 |
2003年 | 26篇 |
2002年 | 21篇 |
2001年 | 25篇 |
2000年 | 27篇 |
1999年 | 18篇 |
1998年 | 18篇 |
1997年 | 19篇 |
1996年 | 8篇 |
1994年 | 9篇 |
1993年 | 8篇 |
1992年 | 9篇 |
1990年 | 12篇 |
1989年 | 9篇 |
1988年 | 8篇 |
1987年 | 8篇 |
1986年 | 12篇 |
1985年 | 15篇 |
1984年 | 12篇 |
1983年 | 8篇 |
1982年 | 15篇 |
1981年 | 9篇 |
1979年 | 11篇 |
1978年 | 16篇 |
1976年 | 11篇 |
1975年 | 14篇 |
1973年 | 10篇 |
1971年 | 11篇 |
1970年 | 8篇 |
1969年 | 13篇 |
1968年 | 9篇 |
1967年 | 10篇 |
排序方式: 共有1060条查询结果,搜索用时 78 毫秒
81.
82.
83.
84.
Stozhkov Y. I. Filippov M. V. Logachev V. I. Makhmutov V. S. 《Physics of Atomic Nuclei》2021,84(6):1007-1010
Physics of Atomic Nuclei - In the last two decades the new experimental data on cosmic rays concerning energy spectra in a wide energy range up to 10 $${}^{14}$$ eV, isotropy, ratio of positron... 相似文献
85.
Thermocapillary convection in a plane horizontal fluid layer with concentrated heating of the free surface is modeled numerically using the Navier-Stokes equations and the heat transport equation. This makes it possible to examine the structure of the convection throughout the fluid volume, in particular in the region where the motion is weak. The deformation of the free surface is assumed to be negligibly small. In the case of a ponderable fluid this assumption is justified given certain upper and lower constraints on the temperature difference and the thickness of the layer, respectively, [9, 10]. Under conditions of weightlessness a fluid layer of constant thickness in a rectangular channel can be realized at a contact angle of 90° [7].Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 4, pp. 108–113, July–August, 1987. 相似文献
86.
The molecular properties of regular star-shaped polystyrenes with different numbers of arms (6, 12, and 22) and different
structures of the branching center (one or two covalently bonded fullerene C60 molecules) are studied by static light scattering;
translational diffusion; and viscometry in toluene, THF, and chloroform. The lengths of the arms for the studied polymer stars
are found to be the same. (The molecular mass of the arm is 8.1 × 103.) The molecular mass and hydrodynamic sizes of macromolecules are estimated. It is shown that the conformational and hydrodynamic
characteristics of polymer stars remain practically unchanged on passage from THF to chloroform. Compared to the linear analog,
star-shaped fullerene-containing PSs are characterized by a higher density of the molecular coil. The shape of their macromolecules
differs insignificantly from spherical, in consistence with theoretical predictions for polymer stars with relatively short
arms. 相似文献
87.
N. V. Tsvetkov L. N. Andreeva S. K. Filippov S. V. Bushin M. A. Bezrukova I. A. Marchenko I. A. Strelina V. P. Alyab’eva N. V. Girbasova A. Yu. Bilibin 《Polymer Science Series A》2010,52(1):8-18
Acrylic polymers containing side dendrons of the third generation based on L-aspartic acid have been studied via the methods of molecular hydrodynamics, dynamic and static light-scattering, optics,
and electrooptics. There are marked differences in hydrodynamic and optical properties of the macromolecules under study and
previously examined polymers with side dendrons of first and second generations. In the range of degrees of polymerization
from 10 to 40, these macromolecules possess an extremely low shape asymmetry. Experiments demonstrate the predominant orientation
of end side dendrons along the main molecular chain. In chloroform solutions, the orientation of macromolecules in hydrodynamic
and electric fields occurs according to the large-scale mechanism. In dichloroacetic acid, the hydrodynamic dimensions of
macromolecules decrease, an effect that is accompanied by an increase in the kinetic flexibility of polymer chains. 相似文献
88.
N. S. Domnina O. Yu. Sergeeva A. N. Koroleva O. V. Rakitina L. A. Dobrun S. K. Filippov M. E. Mikhailova A. V. Lezov 《Polymer Science Series A》2010,52(9):900-906
Water-soluble conjugates are prepared via the chemical modification of poly(vinyl alcohol) and poly(ethylene glycol) by antioxidants
taken from the family of sterically hindered phenols. The effects of the degree of substitution of conjugates on the dimensions
of molecules and their aggregates are studied by viscometry and light scattering in dilute solutions. It is shown that an
increase in the amount of antioxidant groups incorporated into the poly(vinyl alcohol) chain leads to a decrease in the dimensions
of single conjugate molecules owing to attraction of hydrophobic groups. Poly(ethylene glycol) molecules carrying end groups
of sterically hindered phenols form micellar aggregates that are absent in the solution of the initial polymer. The mean number
of molecules involved in such an aggregate is 83. It is found that the presence of hydrophobic end groups in poly(ethylene
glycol) molecules causes a sharp reduction in the lower critical solution temperature of a solution relative to that of the
initial polymer. 相似文献
89.
V. A. Aleksandrov A. S. Sabirov G. M. Filippov 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2011,5(6):1144-1147
The effect of tunneling on inelastic processes in atomic collision physics has been studied using two examples: head-on collision
between hydrogen atoms and protons and hydrogen-atom reflection from an impenetrable wall. These phenomena are analyzed using
the numerical solution of the nonstationary Schr?dinger equation. 相似文献
90.