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21.
An analytical iterative procedure has been established to determine the amplitude of a laser beam propagating through an active
medium. The treatment is valid for both homogeneous and inhomogeneous broadening, and for arbitrary inhomogeneities of the
parameters characterizing the active medium, namely, the refractive index, the small-signal gain and the saturation intensity.
After a supplementary approximation, a thin-sheet gain approach is derived from the first iteration. The formalism enables
us to provide analytical criteria for evaluating both the accuracy of each iteration and the propagation distances for which
the thin-sheet solution can be used.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
22.
Background
The involvement of astrocyte water channel aquaporin-4 (AQP4) in autoimmune diseases of the central nervous system has been suggested following the identification of AQP4 autoantibodies in neuromyelitis optica, an inflammatory demyelinating disease. 相似文献23.
MARTI´NEZ C. Encinas-Sanz F. Serna J. MEJI´AS P. M. MARTI´NEZ-HERRERO R. 《Optical and Quantum Electronics》1997,29(9):923-931
A simple analytical model is proposed to describe the transversal spatial structure of a tridimensional rotationally symmetric
pulsed beam. The spatial behaviour of the pulse amplitude is shown to be linked to its (measurable) second- and higher-order
intensity moments, namely, beam width, quality parameter and kurtosis. As an illustrative experimental example, this model
has been applied to high-quality TEA CO2 laser pulses.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
24.
A. N. Aleinik A. N. Baldin E. A. Bogomazova I. E. Vnukov B. N. Kalinin A. S. Kubankin N. N. Nasonov G. A. Naumenko A. P. Potylitsyn A. F. Sharafutdinov 《JETP Letters》2004,80(6):393-397
Parametric X-ray radiation (PXR) due to dynamic diffraction of relativistic electrons is experimentally observed at small angles to the propagation velocity of electrons in a tungsten crystal. The specific features of the experimental method are described, and forward PXR reflections from two crystallographic planes of tungsten are reliably measured. 相似文献
25.
K. A. Vokhmyanina A. A. Kaplii A. S. Kubankin V. S. Sotnikova T. B. Nikulicheva A. S. Chepurnov 《Moscow University Physics Bulletin》2017,72(1):45-50
Experimental data on the mechanism of the grazing interaction of fast electron beams with planar dielectric surfaces of various materials are analyzed. New experimental results regarding the grazing interaction between electrons with an energy of 10 keV and metalized structured surfaces are reported. The difference between the processes of the interaction of fast electron beams with planar and structured surfaces is demonstrated. 相似文献
26.
Let pn be the nth prime. Then this paper is concerned with provingthe following result on the distribution of consecutive primes. The exponent of x in this theorem improves on the work of Heath-Brownwho proved (1) with exponent . Under the Riemann hypothesisone can prove (1) with exponent .The proof of the theorem startswith the Heath-BrownLinnik identity which leads to aformula giving the number of primes in an interval in termsof coefficients of certain Dirichlet series. I then estimatethe coefficients by using, among other things, the informationwhich can be gained from Montgomery's mean value theorem andHuxley's version of the Hal' asz lemma. Furthermore, by usingfamiliar sieve arguments I am able to discard some of the coefficientsallowing us to gain an improvement over the previous resultof Heath-Brown. 1991 Mathematics Subject Classification: 11N05. 相似文献
27.
Oleinik A. N. Karataev P. V. Klenin A. A. Kubankin A. S. Fedorov K. V. Shchagin A. V. 《Russian Physics Journal》2020,63(1):119-125
Russian Physics Journal - The paper focuses on the surfaces electrization of Z-cut single-crystal lithium niobate during the pyroelectric effect. It is shown that the properties of the electric... 相似文献
28.
I. A. Kishchin A. S. Kubankin T. B. Nikulicheva Al-Omari A. V. Sotnikov A. S. Starovoitov 《Physics of Atomic Nuclei》2016,79(13):1560-1564
Transformation of the Vavilov–Cherenkov radiation cone under grazing interaction of a relativistic electron with a layer of substance is theoretically studied. It is shown that this effect can occur when the electron enters the substance layer. 相似文献
29.
The time-dependent Schrödinger equation is solved numerically for the case of a Gaussian wave packet incident on a time-varying potential barrier. The time evolving reflection and transmission probabilities of the wave packet are computed for several different time-dependent boundary conditions obtained by reducing or increasing the height of the potential barrier. We show that in the case when the barrier height is reduced to zero, a time interval is found during which the reflection probability is larger (superarrivals) compared to the unperturbed case. We further show that the transmission probability exhibits superarrivals when the barrier is raised from zero to a finite value of its height. Superarrivals could be understood by ascribing the features of a real physical field to the Schrödinger wave function which acts as a carrier through which a disturbance, resulting from the boundary condition being perturbed, prpagates from the barrier to the detectors measuring reflected and transmitted probabilities. The speed of propagation of this effect depends upon the rate of reducing or raising the barrier height, thus suggesting an application for secure information transfer using superarrivals. 相似文献
30.
A. N. Eliseev A. S. Kubankin R. M. Nazhmudinov N. N. Nasonov V. I. Sergienko A. V. Subbotin G. G. Subbotin V. A. Khablo 《JETP Letters》2009,90(6):438-440
The enhancement of the yield of parametric X-ray radiation from 7-MeV electrons incident at a grazing angle on the silicon
crystal surface has been experimentally detected. 相似文献