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11.
L. K. Aminov I. N. Kurkin D. A. Lukoyanov K. P. Chernov 《Physics of the Solid State》1997,39(8):1184-1186
Results are reported for measurements of the spin-lattice relaxation times of E′1 centers in quartz glass, produced by neutron irradiation, with the measurements made at two frequencies 9.25 and 24.0 GHz
over a wide temperature interval 1.5–300 K. The experimental data are interpreted on the basis of interaction mechanisms of
the spins with two-level systems with excitation energies ∼6, ∼26, and ∼420 cm−1. A small modification of the existing theory allows us to explain a number of features of the observed temperature and frequency
dependence of the relaxation rate. The results are compared with the data available in the literature on spin-lattice relaxation
of irradiation centers in crystalline quartz and quartz glass.
Fiz. Tverd. Tela (St. Petersburg) 39, 1335–1337 (August 1997) 相似文献
12.
The dependence of the beam propagation factor (M
2 parameter) with the absorbed pump power in the case of monolithic microchip laser under face-cooled configuration is extensively
studied. Our investigations show that the M
2 parameter is related to the absorbed pump power through two parameters (α and β) whose values depend on the laser material properties and laser configuration. We have shown that one parameter arises due
to the oscillation of higher order modes in the microchip cavity and the other parameter accounts for the spherical aberration
associated with the thermal lens induced by the pump beam. Such dependency of M
2 parameter with the absorbed pump power is experimentally verified for a face-cooled monolithic microchip laser based on Nd3+ -doped GdVO4 crystal and the values of α and β parameters were estimated from the experimentally measured data points. 相似文献
13.
V. Palyok I.A. Szabó D.L. Beke A. Kikineshi 《Applied Physics A: Materials Science & Processing》2002,74(5):683-687
Surface relief formation at holographic recording on amorphous selenium films was demonstrated and investigated. The presence
of this optical phase modulation component is essential for ensuring significant, stable and erasable optical recording in
a-Se films at 290–320 K temperatures, where conventional photodarkening was known as insignificant and unstable. Photocrystallization
can only be observed in super-exposed a-Se films at the given experimental conditions of hologram recording. Erasing behavior
of surface relief gratings under heat treatment was also investigated in order to reveal further details of the mechanism.
Photoinduced structural transformations within the amorphous phase, connected to local ordering under the condition of light-induced
fluidity, are proposed as an explanation for the relief formation and erasing. The observed reversible optical recording process
may be useful for the various optoelectronic applications of photoconductive a-Se layers.
Received: 12 June 2000 / Accepted: 6 June 2001 / Published online: 30 August 2001 相似文献
14.
D. V. Vyalykh A. M. Shikin G. V. Prudnikova A. Yu. Grigor’ev A. G. Starodubov V. K. Adamchuk 《Physics of the Solid State》2002,44(1):164-170
This paper reports on the first experimental observation of quantum-well states and sp-type resonances in thin single-crystal gold, silver, and copper layers formed on single-crystal W(110) surfaces, which result from spatial localization of Bloch-type electronic wave functions in a quantum well with potential barriers at the vacuum/metal and metal/W(110) interfaces. The quantization of the valence-band electronic structure in Au/W(110), Ag/W(110), and Cu/W(110) systems was studied experimentally using angle-resolved photoelectron spectroscopy. 相似文献
15.
The problem of the vector and axial-vector dominance of weak interactions within the framework of the quark model of superconductivity type is discussed. 相似文献
16.
17.
18.
19.
A. I. Shtern 《Russian Journal of Mathematical Physics》2006,13(2):210-223
As was proved by van der Waerden in 1933, every finite-dimensional locally bounded representation of a semisimple compact
Lie group is continuous. This is the famous “van der Waerden continuity theorem,” and it motivated a vast literature. In particular,
relationships between the assertion of the theorem (and of the inverse, in a sense, to this theorem) and some properties of
the Bohr compactifications of topological groups were established, which led to the introduction and the study of certain
classes of the so-called van der Waerden groups and algebras. Until now, after more than 70 years have passed, the van der
Waerden theorem appears in monographs and surveys in diverse forms; new proofs were found and then simplified in important
special cases.
In this paper, we prove that the statement of the van der Waerden theorem remains valid for all (not necessarily compact)
real semisimple Lie groups, i.e., any given finite-dimensional representation of a real semisimple Lie group is continuous
if and only if this representation is locally bounded.
More subtle results are also obtained. The main theorem contains several conditions equivalent to the continuity condition
for a finite-dimensional representation. In particular, it is proved that every finite-dimensional representation of a real
semisimple Lie group is continuous if and only if the restriction of this representation to the “compact” part, to the Abelian
part, or to the nilpotent part of the Iwasawa decomposition is locally bounded, and the original van der Waerden theorem is
also somewhat refined. For instance, the following assertion holds: every finite-dimensional representation of a compact semisimple
Lie group is continuous if and only if the restriction of this representation to some maximal torus is locally bounded.
Dedicated to the memory of George Mackey (1916–2006)
Partially supported by the Russian Foundation for Basic Research under grant no. 02-01-00574, by the Program of Supporting
the Leading Scientific Schools under grant no. NSh 619.203.1, and by the INTAS grant. 相似文献
20.
A. I. Nazarov 《Journal of Mathematical Sciences》2006,133(3):1314-1327
We find logarithmic small ball asymptotics for the L2-norm with respect to self-similar measures for a certain class of Gaussian processes including Brownian motion, Ornstein-Uhlenbeck
process, and their integrated counterparts. Bibliography: 46 titles.
__________
Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 311, 2004, pp. 190–213. 相似文献