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171.
G. E. Volovik 《JETP Letters》1997,65(7):522-527
The efficiency of conversion of the heat flux into hard x radiation (HXR) is analyzed, via time-dependent two-temperature
one-dimensional non-LTE-radiation-hydrodynamic numerical modeling, for a heat-to-radiation flux converter linked to the edge
of a low-atomic-number hot Z-pinch. The domain of parameters in this scheme is found where about the same HXR yield can be
achieved at values of input energy which are an order of magnitude lower than in the conventional scheme of a radially imploding
plasma.
Pis’ma Zh. éksp. Teor. Fiz. 65, No. 7, 502–506 (10 April 1997)
Published in English in the original Russian Journal. Edited by Steve Torstveit. 相似文献
172.
L. Bugliaro J. Fröhlich G.M. Graf J. Stubbe C. Fefferman 《Communications in Mathematical Physics》1997,187(3):567-582
A Lieb-Thirring-Sobolev type inequality for Pauli Hamiltonians with magnetic fields is derived. The bound is in terms of an
effective field, whose energy is comparable to that of the magnetic field itself. An application to the stability of matter
in magnetic fields is given.
Received: 19 September 1996 / Accepted: 3 January 1997 相似文献
173.
The diffuse scattering of x rays in a four-layer waveguide-type heterostructure is investigated. The dynamic enhancement of
diffuse scattering is detected experimentally in regions corresponding to the excitation of waveguide modes for both the incident
and scattered waves.
Pis’ma Zh. éksp. Teor. Fiz. 66, No. 4, 219–223 (25 August 1997) 相似文献
174.
I. Peshko G. Galich M. Lopiychuk A. Khizhnyak V. Nakvasuk 《Optics & Laser Technology》1997,29(4):211-215
A laser system containing four CW Nd:YAG double-rod lasers, transforming optics and a fibre with input-output optics has been designed and investigated. It is shown that reduction of the beam parameter product of the non-Gaussian beams in the image space of the lens has made it possible to collect the emission of four lasers to the same fibre. Independent laser operation has provided the output power control in the range of 10–900 W with a stable light spot size on the input end of the fibre. 相似文献
175.
176.
We show that “top-down” mechanisms of ultrahigh-energy cosmic rays which involve heavy relic particle-like objects predict
a Galactic anisotropy of the highest-energy cosmic rays at the level of minimum ∼ 20%. This anisotropy is large enough to
be either observed or ruled out in the next generation of experiments.
Pis’ma Zh. éksp. Teor. Fiz. 68, No. 2, 99–103 (25 July 1998)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
177.
We show that an electron confined to a single finite parabolic quantum well in crossed electric and magnetic fields can behave as a double quantum well system. The magnetic field is parallel to the heterostructure layers and the electric field is perpendicular to those. For a suitable choice of both fields and quantum well width, the electron can be confined to a double quantum well effective potential that is very similar to the electronic potential model for diatomic molecules. The double quantum well spectrum is calculated using a numerical algorithm based on semiclassical methods. A physical interpretation of this quantum system is given based on the analogy to the electrons bound to diatomic molecules. 相似文献
178.
V. G. Lapin 《Radiophysics and Quantum Electronics》1995,38(3-4):195-198
It is shown that the nonstable character of nonlinear interaction of a system of waves similar to that resulting from double stimulated Brillouin scattering is retained upon the oblique incidence of a powerful electromagnetic wave on a layer of supercritical plasma. In this case we have nonlinear back reflection from a layer of supercritical plasma. The threshold intensity of the pump wave is greater than that in the case of subcritical plasma for TE polarization waves but can markedly decrease for waves polarized in the incidence plane. Instability is possible only for a layer of finite thickness.Radiophysical Research Institute, Nizhny Novgorod. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 38, Nos. 3–4, pp. 298–303, March–April, 1995. 相似文献
179.
Flowing and static gas-phase samples of HNO3 in O2 and N2 were analyzed by long-path ultraviolet/visible (UV/VIS) spectroscopy to reveal the presence of both NO2 and NO3, the concentrations of which were calculated using differential absorption cross sections. NO2 is produced predominantly by the heterogeneous decomposition of HNO3, whereas NO3 is generated in the gas phase by the thermal decomposition of N2O5, a product of the self-disproportionation of liquid HNO3. © 1993 John Wiley & Sons, Inc. 相似文献
180.
R. Grac M. Pugnet J.H. Collet B. Lambert C. De Matos H. L'Haridon A. Le Corre J.O. White 《Superlattices and Microstructures》1997,22(4):505-509
We report new results on the diffraction properties of photoinduced gratings in InGaAs/InGaAsP MQW structures. The original feature of this device is that the QWs are enclosed in an asymmetric Fabry–Perot microcavity in order to increase the diffraction efficiency. We observe oscillations in the diffraction efficiency due to resonant effects in the microcavity. The experimental spectra are compared with theory. Diffraction efficiency at 1.55 μm attains a maximum value of 2.7% at a write beam fluence of 260 μ J cm−2, and then decreases at higher fluences. We explain this phenomenon by an absorption saturation at high excitation. 相似文献