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71.
V. M. Aulchenko M. N. Achasov S. E. Baru K. I. Beloborodov A. V. Berdyugin A. G. Bogdanchikov A. V. Bozhenok A. D. Bukin D. A. Bukin A. V. Vasilev V. B. Golubev T. V. Dimova V. P. Druzhinin V. N. Ivanchenko I. A. Koop A. A. Korol S. V. Koshuba A. P. Lysenko A. V. Otboev E. V. Pakhtusova A. A. Salnikov S. I. Serednyakov V. A. Sidorov Z. K. Silagadze V. V. Shary Yu. M. Shatunov 《Journal of Experimental and Theoretical Physics》2003,97(1):24-33
The process e + e ? → η′γ, η′ → η π0π0, η → γγ is investigated by an SND detector in experiment on a VEPP-2M equipment with colliding electron-positron beams. The analysis of experimental data yields a value of B(? → η′γ)=(6.7 ?4.2 +5.0 ±1.5)×10?5 for the decay probability. Taking into account a previous measurement of this quantity by an SND detector in the decay channel η′ → π+π?η, one finally obtains B(?→η ′γ)=(6.7 ?2.4 +2.8 ±0.8)×10?5. 相似文献
72.
A nonperturbatve theory of energy losses of fast heavy multiply charged structural ions in collisions with neutral complex atoms is elaborated with allowance for simultaneous excitations of ionic and atomic electron shells. Formulas for the effective deceleration that are similar to the well-known Bethe-Bloch formulas are derived. By way of example, the energy lost by partially stripped U q+ ions (10 ≤ q ≤ 70) colliding with argon atoms and also the energy lost by Au, Pb, and Bi ions colliding with various targets are calculated. The results of calculation are compared with experimental data. 相似文献
73.
V. V. Novikov A. V. Matovnikov T. A. Chukina A. A. Sidorov E. A. Kul’chenkov 《Physics of the Solid State》2007,49(11):2034-2037
This paper reports an experimental study of the heat capacity and crystal lattice parameters of a polycrystalline sample of yttrium diboride prepared by high-temperature synthesis from elements. The electronic and lattice contributions to the heat capacity are isolated. The temperature dependences of the characteristic temperature, the linear thermal expansion coefficients αa(T) and α c (T), the bulk thermal expansion coefficient β(T), and the Grüneisen coefficient are calculated. A region of negative values of α c (T) and β(T) is revealed. Anharmonicity is found to exert only a minor effect on the YB2 lattice dynamics over a larger part of the temperature range covered. 相似文献
74.
Magnesium diboride has been thermally treated in the presence of Rb, Cs, and Ba. The magnetic susceptibility shows the possible
onsets of superconductivity in the resulting samples at 52 K (Rb), 58 K (Cs), and 45 K (Ba). Room-temperature 11B NMR indicates the cubic symmetry of the electric field gradient at the boron site for the samples reacted with Rb and Cs,
in contrast to the axial symmetry in the initial MgB2 and in the sample treated with Ba.
The text was submitted by the authors in English. 相似文献
75.
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The principles of constructing optical devices on the basis of diffractive structures with a vanadium dioxide film for the
control of radiation in the mid-IR range are analyzed. Methods are described for the practical implementation of such devices
at λ=10.6 μm, and their response characteristics are calculated. It is shown that a contrast of 1:107 can be attained in diffractive optical elements, and the actuation time of the elements when switched on by an intense laser
beam can be shortened to tens of nanoseconds.
Zh. Tekh. Fiz. 69, 91–96 (November 1999) 相似文献
79.
S. P. Sidorov 《Mathematical Notes》2008,84(3-4):561-567
Suppose that X is a linear space and L 1, …, L n is a system of linearly independent functionals on P, where P ? X is a bounded set of dimension n + 1. Suppose that the linear functional L 0 is defined in X. In this paper, we find an algorithm that recovers the functional L 0 on the set P with the least error among all linear algorithms using the information L 1 f, …, L n f, f ∈ P. 相似文献
80.