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961.
SWAN系统中雷达反射率因子质量控制算法及其应用 总被引:4,自引:0,他引:4
介绍了SWAN系统中雷达反射率因子质量控制算法原理,包括数据预处理、孤立噪声回波过滤、超折射回波抑制3部分.数据预处理将原始雷达资料转换为统一的RD20格式,并检测数据质量.孤立噪声回波过滤包括双向搜索、回波特征量过滤法.超折射(Anomalous Propagation,AP)回波抑制采用模糊逻辑原理.介绍算法配置参数,通过对比分析武汉、随州、西安雷达AP识别因子概率分布图可知,三者是类似的,表明默认参数的适用性.评估表明,该方法可过滤掉大部分AP回波,缺点是未能识别部分远距离AP回波以及错误识别部分降水回波. 相似文献
962.
A. Feoli 《Astronomische Nachrichten》2014,335(2):193-197
We propose a classification of supermassive black holes (SMBHs) based on their efficiency in the conversion of infalling mass in emitted radiation. We use a theoretical model that assumes a conservation of angular momentum between the gas falling inside the hole and the photons emitted outwards, and suggests the existence of the scaling relation M•‐Reσ3, where M• is the mass of the central SMBH, whereas Re and σ are the effective radius and velocity dispersion of the host galaxies (bulges), respectively. We apply our model on a data set of 57 galaxies of different morphological types and with M• measurements, obtained through the analysis of Spitzer /IRAC 3.6‐µ m images. In order to find the best fit of the corresponding scaling law, we use the FITEXY routine to perform a least‐squares regression of M• on Reσ3 for the considered sample of galaxies. Our analysis shows that the relation is tight and our theoretical model allows to easily estimate the efficiency of mass conversion into radiation of the central SMBHs. Finally we propose a new appealing way to classify the SMBHs in terms of this parameter. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
963.
Andrea Merloni Sebastian Heinz Tiziana Di Matteo 《Astrophysics and Space Science》2005,300(1-3):45-53
We examine the disc-jet connection in stellar mass and supermassive black holes by investigating the properties of their compact
emission in the hard X-ray and radio bands. We compile a sample of ∼100 active galactic nuclei with measured mass, 5 GHz core
emission, and 2–10 keV luminosity, together with eight galactic black holes with a total of ∼50 simultaneous observations
in the radio and X-ray bands. Using this sample, we study the correlations between the radio (LR) and the X-ray (LX) luminosity and the black hole mass (M). We find that the radio luminosity is correlated with both M and LX, at a highly significant level. We show how this result can be used to extend the standard unification by orientation scheme
to encompass unification by mass and accretion rate. 相似文献
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当前广泛开展的网络多媒体业务都存在不同程度的服务不稳定情况,其原因是架构于网络上的多媒体业务缺乏整体有效的网络控制机制.基于研究提出了一种基于聚合点的拥塞控制方法,能对网络多媒体业务进行有效的拥塞控制.与现有业务实施机制相比,该方案实现简单,能更有效保证业务的开展. 相似文献
966.
J. Crummy A. C. Fabian L. Gallo R. R. Ross 《Monthly notices of the Royal Astronomical Society》2006,365(4):1067-1081
We present a large sample of type 1 active galactic nuclei (AGN) spectra taken with XMM–Newton , and fit them with both the conventional model (a power law and blackbody) and the relativistically blurred photoionized disc reflection model of Ross & Fabian. We find that the disc reflection model is a better fit. The disc reflection model successfully reproduces the continuum shape, including the soft excess, of all the sources. The model also reproduces many features that would conventionally be interpreted as absorption edges. We are able to use the model to infer the properties of the sources, specifically that the majority of black holes in the sample are strongly rotating, and that there is a deficit in sources with an inclination >70°. We conclude that the disc reflection model is an important tool in the study of AGN X-ray spectra. 相似文献
967.
ON REGIONAL DIFFERENTIATION OF RIVER WATER ENVIRONMENT CAPACITY AND STRATEGIES TO CONTROL WATER ENVIRONMENT POLLUTION IN CHINA 总被引:2,自引:0,他引:2
ONREGIONALDIFFERENTIATIONOFRIVERWATERENVIRONMENTCAPACITYANDSTRATEGIESTOCONTROLWATERENVIRONMENTPOLLUTIONINCHINA¥WangHuadong(王华... 相似文献
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