全文获取类型
收费全文 | 1145篇 |
免费 | 7篇 |
国内免费 | 4篇 |
专业分类
化学 | 428篇 |
晶体学 | 25篇 |
力学 | 100篇 |
数学 | 183篇 |
物理学 | 420篇 |
出版年
2022年 | 11篇 |
2021年 | 17篇 |
2020年 | 19篇 |
2019年 | 25篇 |
2018年 | 29篇 |
2017年 | 39篇 |
2016年 | 34篇 |
2015年 | 21篇 |
2014年 | 40篇 |
2013年 | 40篇 |
2012年 | 42篇 |
2011年 | 50篇 |
2010年 | 54篇 |
2009年 | 38篇 |
2008年 | 43篇 |
2007年 | 38篇 |
2006年 | 38篇 |
2005年 | 26篇 |
2004年 | 42篇 |
2003年 | 21篇 |
2002年 | 27篇 |
2001年 | 21篇 |
2000年 | 27篇 |
1999年 | 14篇 |
1998年 | 17篇 |
1997年 | 11篇 |
1996年 | 16篇 |
1995年 | 9篇 |
1994年 | 12篇 |
1993年 | 13篇 |
1992年 | 13篇 |
1991年 | 11篇 |
1990年 | 12篇 |
1989年 | 9篇 |
1985年 | 15篇 |
1984年 | 14篇 |
1983年 | 13篇 |
1982年 | 16篇 |
1981年 | 15篇 |
1979年 | 16篇 |
1978年 | 9篇 |
1977年 | 16篇 |
1976年 | 13篇 |
1975年 | 13篇 |
1974年 | 12篇 |
1971年 | 8篇 |
1970年 | 8篇 |
1969年 | 11篇 |
1965年 | 9篇 |
1962年 | 10篇 |
排序方式: 共有1156条查询结果,搜索用时 31 毫秒
61.
62.
Size effects on polaritons in thin plane parallel CdS and CdSe crystals are discussed. For samples not thinner than 0.1 μm the measurements of transmittance and reflectance show the size quantization of the mechanical exciton dispersion and a shift of the resonance frequency of the exciton to the high-energy side with decreasing thickness. However no evidence for the alteration of the oscillator strength or other parameters has been obtained. This conclusion is in conflict with the recently published data taken on CdS samples. The stability of the polariton dispersion in our case is supported by the theoretical study of reflectance ignoring the effects of the finiteness of the exciton radius. 相似文献
63.
64.
65.
G. M. Abramova A. M. Vorotynov G. A. Petrakovskii N. I. Kiselev D. A. Velikanov A. F. Bovina R. F. Al’mukhametov R. A. Yakshibaev É. V. Gabitov 《Physics of the Solid State》2004,46(12):2225-2228
Electrical, resonant, and magnetic properties of intercalated copper chromium disulfide CuCrS2 are studied. It is established that CuCrS2 is an antiferromagnetic semiconductor with Néel temperature TN=40.7 K and an effective magnetic moment of 4.3µB. Anomalies in the electrical, magnetic, and resonant properties of CuCrS2 are found at Tc=110 K, which suggest an electron transition accompanied by alteration of the valences of the 3d-metal ions. 相似文献
66.
I. A. Luk’yanchikova D. V. Ivlev M. G. Kiselev G. A. Al’per 《Russian Journal of General Chemistry》2004,74(8):1156-1162
The concentration dependence of the viscosity of tert-butanol-water mixtures in the range of tert-butanol mole fractions from 0 to 0.02 was studied experimentally and by computer simulation. The methods of potentials of mean force and statistical geometry were successfully applied to analysis of physical factors responsible for the extrema in the composition-property dependences. The maximum in the concentration dependence of the viscosity is due to association of solvent molecules.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 8, 2004, pp. 1250–1256.Original Russian Text Copyright © 2004 by Lukyanchikova, Ivlev, Kiselev, Alper.This revised version was published online in April 2005 with a corrected cover date. 相似文献
67.
Kiselev V. D. Kashaeva E. A. Iskhakova G. G. Shikhab M. S. Konovalov A. I. 《Russian Journal of General Chemistry》2003,73(2):213-217
External pressure was found to similarly affect the rate of a gallium chloride-catalyzed Diels-Alder reaction between 9-methylanthracene with acrylonitrile and a noncatalyzed reaction of 9,10-dimethylanthracene with acrylonitrile. The observation of equal activation volumes is consistent with the assumption that elevated pressure very weakly affects the bond energy in the n, complex of acrylonitrile with gallium chloride. 相似文献
68.
R.?OppermannEmail author D.?Sherrington M.?Kiselev 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,37(2):187-192
We define modulated replica symmetry breaking (RSB) schemes which combine tree- and wave-like structures. A modulated scheme and unmodulated RSB are evaluated at 1-step level for a semiconductor model with antiferromagnetic Korenblit-Shender interaction. By comparison of the free energies we find evidence that a T = 0 phase transition in the ferrimagnetic phase leads to a transition between the different RSB-schemes. An embedding factor of Parisi block matrices with sublattice-asymmetrical size is employed as a new variational parameter in the modulated scheme.Received: 11 December 2003, Published online: 15 March 2004PACS:
68.35.Rh Phase transitions and critical phenomena - 75.10.Nr Spin glass and other random models 相似文献
69.
N. N. Kolachevskiĭ A. A. Papchenko N. A. Kiselev V. N. Sorokin A. V. Akimov S. I. Kanorskii 《Optics and Spectroscopy》2001,90(2):164-170
Spectra of saturated absorption of Sm atomic vapor from the ground state 7 F 0 and the first even metastable level 7 F 1, ε′=292.58 cm?1 of the 4f 66s 2 configuration to the odd level 4f 6(7 F)6s6p(3 P o)9 F 1 o , ε,=14863.85 cm?1 were recorded. The lines of the isotopic series were identified, and the hyperfine structure of lines in the spectra of isotopes with a nonzero nuclear spin was determined. The relative isotopic shifts and the hyperfine splitting of the even level 4f 66s 2(7 F 1) were determined. 相似文献
70.
V. N. Nevolin V. Yu. Fominski A. G. Gnedovets G. A. Kiselev 《Technical Physics》2007,52(11):1475-1482
A mathematical model describing the dynamics of a pulsed laser plasma with multiply charged ions, as well as the formation of the accelerated ion flow in an external magnetic field, is developed. Experimental studies and mathematical simulation by the particle-in-cell method are used to determine the role of multiply charged ions in the process of ion implantation into a silicon substrate from the pulsed plasma containing singly and doubly charged titanium ions. The plasma spreads between parallel-plate electrodes (Ti target and Si substrate) along the normal to the surface of the target. Ions are accelerated by high-voltage negative pulses applied to the substrate. It is found that doubly charged ions effectively participate in the implantation process when an external electric field is applied very soon after the laser action on the target. The application of a high-voltage pulse with an amplitude of 50 kV 0.5 μs after a laser pulse leads to ion implantation with an energy close to 100 keV. With increasing delay in the application of the high-voltage pulse, the upper boundary of the energy spectrum of implanted ions is displaced towards lower energies. Comparison of the depth profiles of titanium distribution in silicon calculated from the results of simulation are compared with the experimental profiles shows that the model developed here correctly describes the formation of the high-energy component of the ion flow, which is responsible for defect formation and doping of deep layers of the substrate. 相似文献