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131.
Franca Chiuderi Drago 《Space Science Reviews》1994,70(1-2):279-282
Different models of coronal streamers are used to calculate the radio brightness temperature at the wavelengths of observation of the Nançays Radioheliograph. Calculation are performed assuming the location of the streamer both on the disk and at the limb. Their comparison with observations show that a satisfactory agreement with a particular model can be found in the shape and in the relative enhacement of the streamer with respect to the quiet Sun, although the absolute values of the computed brightness temperatures are much higher than the observed ones. 相似文献
132.
The variability of the radio emission of RS CVn and Algol type binaries has been observed over 70 hours by Lefèvre et al. (1993). In this contribution simple model calculations are applied to discuss the relevant time scales. It is concluded that a significant fraction of the permanent radio emission of these systems is due to flare-like processes of energy release over a wide range of energies. 相似文献
133.
本文给出了薄相屏近似条件下的电离层闪烁Fourier功率谱和Bessel功率谱与电离层不均匀结构电子密度涨落空间谱之间的关系。对窄波瓣天线Riometer获得的宇宙噪声资料进行了分析,结果表明:宇宙噪声资料包含着电离层不均匀结构的信息。Riometer观测结果也可用于电离层闪烁问题的研究。 相似文献
134.
We review the physical processes of particle acceleration, injection, propagation, trapping, and energy loss in solar flare
conditions. An understanding of these basic physical processes is inexorable to interpret the detailed timing and spectral
evolution of the radiative signatures caused by nonthermal particles in hard X-rays, gamma-rays, and radio wavelengths. In
contrast to other more theoretically oriented reviews on particle acceleration processes, we aim here to capitalize on the
numerous observations from recent spacecraft missions, such as from the Compton Gamma Ray Observatory (CGRO), the Yohkoh Hard X-Ray Telescope (HXT) and Soft X-Ray Telescope (SXT), and the Transition Region and Coronal Explorer (TRACE). High-precision energy-dependent time delay measurements from CGRO and spatial imaging with Yohkoh and TRACE provide invaluable observational constraints on the topology of the acceleration region, the reconstruction of magnetic reconnection
processes, the resulting electromagnetic fields, and the kinematics of energized (nonthermal) particles.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
135.
136.
TH230是集成无线和数传专业技术,用于数据传输、无线遥控的多功能电台。介绍TH230专业无线电台的工作原理及其在供配电系统中的应用。 相似文献
137.
138.
可编程数字下变频器的关键技术 总被引:3,自引:0,他引:3
可靠、灵活的数字下变频技术在无线通信系统中得到越来越广泛的应用。文中指出影响数字下变频器性能的主要因素 ,并提出采用经典的 CORDIC算法来降低硬件电路的复杂性。最后 ,用线性内插的方法实现了输入输出速率的分数倍变换 相似文献
139.
140.
C. Bouratzis P. Preka-Papadema X. Moussas C. Alissandrakis A. Hillaris 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
A complex radio event was observed on January 17, 2005 with the radio-spectrograph ARTEMIS-IV, operating at Thermopylae, Greece; it was associated with an X3.8 SXR flare and two fast Halo CMEs in close succession. We present dynamic spectra of this event; the high time resolution (1/100 s) of the data in the 450–270 MHz range, makes possible the detection and analysis of the fine structure which this major radio event exhibits. The fine structure was found to match, almost, the comprehensive Ondrejov Catalogue which it refers to the spectral range 0.8–2 GHz, yet seems to produce similar fine structure with the metric range. 相似文献