全文获取类型
收费全文 | 58篇 |
免费 | 1篇 |
专业分类
化学 | 18篇 |
晶体学 | 1篇 |
力学 | 3篇 |
数学 | 7篇 |
物理学 | 30篇 |
出版年
2022年 | 1篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2014年 | 1篇 |
2013年 | 2篇 |
2011年 | 2篇 |
2009年 | 1篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 3篇 |
2005年 | 4篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1983年 | 1篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1973年 | 1篇 |
1970年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有59条查询结果,搜索用时 46 毫秒
1.
2.
A. V. Bokov V. M. Byakov L. A. Kulikov Yu. D. Perfiliev S. V. Stepanov 《Hyperfine Interactions》2017,238(1):95
Being the main cause of cancer, almost all chemical carcinogens are strong electrophiles, that is, they have a high affinity for the electron. We have shown that positron annihilation lifetime spectroscopy (PALS) is able to detect chemical carcinogens by their inhibition of positronium (Ps) formation in liquid media. Electrophilic carcinogens intercept thermalized track electrons, which are precursors of Ps, and as a result, when they are present Ps atom does not practically form. Available biophysical data seemingly indicate that frozen solutions model better an intracellular medium than the liquid ones. So it is reasonable to use emission Mössbauer spectroscopy (EMS) to detect chemical carcinogens, measuring the yield of 57Fe2+ions formed in reactions of Auger electrons and other secondary electrons they produced with 57Fe3+. These reactions are similar to the Ps formation process in the terminal part the positron track: e++ e? =>Ps. So EMS and PALS are complementary methods for detection of carcinogenic compounds. 相似文献
3.
Propagation of tube waves in an infinite fluid-filled borehole, generated by a single-force point source placed in the elastic surrounding formation, is analyzed in the long-wave approximation. Integral representations of the precise solution are obtained both for fast and slow formations. An asymptotic analysis of tube-wave propagation in the fluid-filled borehole is performed on the basis of these two integral representations. The complete asymptotic wave field in the borehole fluid for a fast formation consists of P and SV phases and the lowest eigenmode of the Stoneley wave (tube wave). For a slow formation the conical Stoneley wave (Mach wave) is generated. It appears only behind the critical angle defined by the ratio of the S wave velocity in the formation to the low-frequency Stoneley wave velocity and decays weakly with an offset. Asymptotic wave forms are in good agreement with wave forms obtained by straightforward calculations. 相似文献
4.
5.
6.
L. P. Avakyants P. Yu. Bokov A. T. Grigoriev A. V. Chervyakov 《Bulletin of the Russian Academy of Sciences: Physics》2008,72(7):941-943
Semi-insulating GaAs(100) substrates subjected to ion plasma etching in different regimes have been investigated by photoreflectance
spectroscopy. The photoreflectance spectra of the processed samples exhibit Franz-Keldysh oscillations, which indicate a decrease
in the defect density in the surface region. On the basis of the experimental data and the results of simulation of the photoreflectance
spectra, optimal regimes of sample etching have been found. 相似文献
7.
A. A. Bokov I. P. Raevskii M. A. Malitskaya S. M. Emel’yanov 《Physics of the Solid State》1998,40(1):96-97
The temperature dependence of the dielectric constant ɛ and the spectral dependence of the photoconductivity of Pb(Mg1/3Ta2/3)O3 crystals are investigated. The width of the band gap (3.4 eV) is determined. It is found that above the temperature of the
maximum of the dielectric constant, its reciprocal 1/ɛ varies with temperature first quadratically and then according to a linear law, as is characteristic of ferroelectrics with
a smeared phase transition. The smearing parameter of the transition estimated from the experimental data is close to the
value calculated assuming the absence of long-range order in the arrangement of the Mg and Ta ions.
Fiz. Tverd. Tela (St. Petersburg) 40, 109–110 (January 1998) 相似文献
8.
L. P. Avakyants P. Yu. Bokov G. B. Galiev V. é. Kaminskii V. A. Kulbachinskii V. G. Mokerov A. V. Chervyakov 《Optics and Spectroscopy》2002,93(6):857-861
Photoreflectance spectra are measured in heterostructures with coupled quantum wells at room temperature. The energies of
the optical transitions are determined, and their variation with the well width and barrier thickness is studied. The experimental
results are compared with the theoretically calculated electron-hole transition energies. Good agreement is obtained for narrow
wells.
__________
Translated from Optika i Spektroskopiya, Vol. 93, No. 6, 2002, pp. 929–934.
Original Russian Text Copyright ? 2002 by Avakyants, Bokov, Galiev, Kaminskiĭ, Kul’bachinskiĭ, Mokerov, Chervyakov. 相似文献
9.
L. P. Avakyants P. Yu. Bokov N. A. Volchkov I. P. Kazakov A. V. Chervyakov 《Optics and Spectroscopy》2007,102(5):712-716
The carrier concentrations in Si-doped n-GaAs films have been determined by Raman and light reflection spectroscopies. The data obtained are in good agreement with the results of Hall measurements. It is shown that the light reflection and Raman spectroscopies supplement each other in determination of carrier concentrations in the range 1017?1019 cm?3. 相似文献
10.
The dependence of the domain-wall velocity on the amplitude of the driving magnetic field pulses is investigated in an iron
garnet film of the (YSmCa)3(FeGe)5O12 system with a (111) orientation. The results obtained are analyzed from the standpoint of existing theory. A maximum corresponding
to the disruption of steady-state motion is observed on the dependence. Thereafter, the velocity at first decreases sharply
and then increases. It is theorized that a process involving the periodic generation, propagation, and annihilation of horizontal
Bloch lines occurs in the wall in this period. Data are obtained for the velocity saturation region, which confirm a previously
proposed empirical formula and a theoretical model, according to which the saturation regime corresponds to a state of chaos.
Fiz. Tverd. Tela (St. Petersburg) 39, 660–663 (April 1997) 相似文献