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Data from Twenty-Three FRB’s Confirm the Universe Is Static and Not Expanding
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作者 Lyndon Errol Ashmore 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第3期1152-1177,共26页
Fast Radio Bursts from far away galaxies have travelled through the IGM and provide a tool to study its composition. Presently there are 23 FRB’s whose host galaxies have been identified and the redshift found. This ... Fast Radio Bursts from far away galaxies have travelled through the IGM and provide a tool to study its composition. Presently there are 23 FRB’s whose host galaxies have been identified and the redshift found. This gives us the opportunity to test Dispersion Measure versus redshift predictions made by two models. The Macquart relation for an expanding Universe and the New Tired Light relationship in a static universe. In New Tired Light, redshifts are produced when a photon is absorbed and re-emitted by the electrons in the IGM which recoil on both occasions. Some of the energy of the photon has been transferred to the kinetic energy of the recoiling electron. The photon has less energy, a lower frequency and a longer wavelength. It has been redshifted. Since dispersion is due to an interaction between radio signals and these same electrons one would expect a direct relationship between DM and redshift in the New Tired light model. The relation is DM=(mec/2hre)ln(1+z)and contains no adjustable parameters—just a combination of universal constants related to the electron and photon. Notice that the relation is independent of the electron number density ne since a change in ne affects both the DM and redshift equally. A graph of DM versus ln(1 + z) will be a straight line of gradient (mec/2hre)and, using SI units, substituting for the constants gives 7.318 × 1025 m−2. Using the data from the 23 well localized FRB’s, with the weighting of the DM’s for expansion removed (so that the data corresponds to a static universe), a graph of DM versus ln(1 + z) has a gradient of 6.7 × 1025 m−2—9% below the predicted (mec/2hre). The Macquart relation involves highly processed data and adjustable parameters to allow for “dark energy” and “dark matter” (neither of which has yet been found) and can be reduced to DM = 850z (in units of pc∙cm−3). Using the data from this set of localized FRB’s gives a trendline with gradient 1.10 × 103 pc∙cm−3—almost 30% higher than that predicted in an expanding universe model. The FRB data clearly comes down in favour of a static universe rather than an expanding one. Combining the DM-z relationship for the 23 well localized FRB’s, with the Hubble diagram, drawn using the NED-D compilation of redshift independent extragalactic distances, produces a value of “ne” the mean electron number density of the IGM, of ne=0.48 m−3close to the value ne=0.5 m−3, long since predicted by NTL. 展开更多
关键词 REDSHIFT Dispersion Measure Fast radio Bursts FRB’s Tired Light Static universe IGM
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A Millimeter-Wave Radio Telescope Project at Seoul National University
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作者 Koo Bon Chul (Department of Astronomy,Seoul National University) 《天文研究与技术》 CSCD 1999年第S1期51-52,共2页
The Department of Astronomy at Seoul National University is carrying out a project to build a radio observatory, the Seoul Radio Astronomical Observatory (SRAO). The observatory will be constructed on our campus, whic... The Department of Astronomy at Seoul National University is carrying out a project to build a radio observatory, the Seoul Radio Astronomical Observatory (SRAO). The observatory will be constructed on our campus, which is located at sea level in Seoul, Korea, at (126°57.′3E, 37°27.′1N). The observatory will operate a 6 m millimeter radio telescope. 展开更多
关键词 A Millimeter-Wave radio Telescope Project at Seoul National university radio WAVE
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Alternative kind of hydrogen atoms as a possible explanation for the latest puzzling observation of the 21 cm radio line from the early Universe 被引量:1
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作者 Eugene Oks 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2020年第7期172-176,共5页
There is a puzzling astrophysical result concerning the latest observation of the absorption profile of the redshifted radio line 21 cm from the early Universe(as described in Bowman et al.). The amplitude of the prof... There is a puzzling astrophysical result concerning the latest observation of the absorption profile of the redshifted radio line 21 cm from the early Universe(as described in Bowman et al.). The amplitude of the profile was more than a factor of two greater than the largest predictions. This could mean that the primordial hydrogen gas was much cooler than expected. Some explanations in the literature suggested a possible cooling of baryons either by unspecified dark matter particles or by some exotic dark matter particles with a charge a million times smaller than the electron charge. Other explanations required an additional radio background. In the present paper, we entertain a possible different explanation for the above puzzling observational result: the explanation is based on the alternative kind of hydrogen atoms(AKHA),whose existence was previously demonstrated theoretically, as well as by the analysis of atomic experiments. Namely, the AKHA are expected to decouple from the cosmic microwave background(CMB) much earlier(in the course of the Universe expansion) than usual hydrogen atoms, so that the AKHA temperature is significantly lower than that of usual hydrogen atoms. This seems to lower the excitation(spin) temperature of the hyperfine doublet(responsible for the 21 cm line) sufficiently enough for explaining the above puzzling observational result. This possible explanation appears to be more specific and natural than the previous possible explanations. Further observational studies of the redshifted 21 cm radio line from the early Universe could help to verify which explanation is the most relevant. 展开更多
关键词 Cosmology:Early universe explanation of the puzzle of 21cm radio line Galaxies:intergalactic medium Cosmology:observations Cosmology:theory
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THE DECOMPOSITION OF THE REPRESENTATIONS Tv AND THE PLANCHEREL FORMULA FOR THE UNIVERSAL COVERING GROUP OF 517(1,1)
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作者 Liu Jianming and Zheng Weixing (Nanjing University, China) 《Analysis in Theory and Applications》 1995年第3期52-61,共10页
The decomposition of the representations T0(v∈R) ore considered here. The Plancherel formula for the universal covering group of SU(1,1) is also deduced.
关键词 THE DECOMPOSITION OF THE REPRESENTATIONS tv AND THE PLANCHEREL FORMULA FOR THE universAL COVERING GROUP OF 517
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CULTURAL,RADIO BROADCASTING AND TV UNDERTAKINGS:Vigorous Development──AN INTERVIEW WITH DEPUTY DIRECTOR TUGYIA
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作者 WEN QUNTAI DEGYI 《China's Tibet》 2000年第5期19-20,共2页
关键词 tv AN INTERVIEW WITH DEPUTY DIRECTOR TUGYIA CULTURAL radio BROADCASTING AND tv UNDERTAKINGS:Vigorous Development
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广播电视制播工程项目中UPS的选用研究
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作者 张莉 《电视技术》 2024年第6期55-58,共4页
对于广播电视制播工程项目,为确保直播内容安全播出和内容编辑的时效性,与直播相关的系统和内容编辑系统的核心设备需要接入不间断电源(Uninterruptible Power Supply,UPS)供电回路。因此,在供配电系统设计过程中,如何选择合适的UPS电... 对于广播电视制播工程项目,为确保直播内容安全播出和内容编辑的时效性,与直播相关的系统和内容编辑系统的核心设备需要接入不间断电源(Uninterruptible Power Supply,UPS)供电回路。因此,在供配电系统设计过程中,如何选择合适的UPS电源设备技术架构成为一个关键问题。主要探讨了广播电视制播工程项目中UPS电源设备的选用,对UPS高频机和UPS工频机进行了比较分析,进而给出了广播电视制播工程中UPS电源设备的选用策略。 展开更多
关键词 广播电视制播工程项目 不间断电源(UPS) 工频机 高频机 选用
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强干扰与通道误差条件下弱信号DOA估计的实验研究
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作者 孙家宝 施伟 王身云 《电子技术应用》 2024年第6期101-106,共6页
在实际测向系统中,当弱信号和强干扰空间临近时,空间谱测向系统仅能对强干扰进行波达方向(Direction of Arrival,DOA)估计,弱信号DOA估计性能下降甚至失效。针对这一问题,研究了空间谱扩展噪声子空间算法结合通道幅相误差校正,在强干扰... 在实际测向系统中,当弱信号和强干扰空间临近时,空间谱测向系统仅能对强干扰进行波达方向(Direction of Arrival,DOA)估计,弱信号DOA估计性能下降甚至失效。针对这一问题,研究了空间谱扩展噪声子空间算法结合通道幅相误差校正,在强干扰抑制条件下对弱信号进行DOA估计的方法。该方法对采样信号的噪声协方差进行去加权处理,并对空间谱扩展噪声子空间算法的空间谱导向矢量进行修正。基于通用软件无线电外设(Universal SoftwareRadioPeripheral,USRP)和印刷偶极子线形天线阵构建实验平台,实验结果证明空间谱扩展噪声子空间算法结合改进的通道幅相误差校正方法,能对临近干扰源进行空间谱抑制的同时,实现对弱信号的DOA估计。 展开更多
关键词 通道幅相误差 校正 扩展噪声子空间 通用软件无线电外设(USRP) 空间谱测向
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基于电信运营商的IPTV新业务定位 被引量:3
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作者 陈晓军 《世界电信》 2005年第7期11-14,共4页
IPTV是电信运营商的一个机遇和挑战。从用户角度出发,应该减小机顶盒的采购成本,降低或转移用户一次性投入,降低用户的进入门槛;从竞争和共赢的角度,应与拥有巨大资源的广电部门合作;要做好积极的宣传引导和网络的升级改造;同时,要积极... IPTV是电信运营商的一个机遇和挑战。从用户角度出发,应该减小机顶盒的采购成本,降低或转移用户一次性投入,降低用户的进入门槛;从竞争和共赢的角度,应与拥有巨大资源的广电部门合作;要做好积极的宣传引导和网络的升级改造;同时,要积极宣传引导消费者,探寻运营模式和营销策略。 展开更多
关键词 IPtv 网络电视 机顶盒 电信运营商
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邻频CATV系统传输无线电视信号的方法探讨
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作者 卢洪武 王东辉 李天平 《山东师范大学学报(自然科学版)》 CAS 1997年第1期30-32,共3页
介绍了有线电视信号的接收方法及邻频有线电视系统的技术要求,比较了几种技术处理方案,从而得出解调再调制是最优方案。
关键词 电视信号处理 无线电视信号 CAtv信号
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TV系统中基于Kalman滤波器的自回归频谱空洞预测
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作者 鲜永菊 曹华孝 《电视技术》 北大核心 2011年第2期71-75,共5页
研究了基于Kalman滤波器的自回归的频谱空洞预测模型。首先讨论了广播电视系统中授权用户和认知用户共存的系统模型;其次讨论了自回归预测原理和Kalman滤波预测的无偏性,并针对不同的通信模式提出不同的预测方法。理论分析和仿真结果均... 研究了基于Kalman滤波器的自回归的频谱空洞预测模型。首先讨论了广播电视系统中授权用户和认知用户共存的系统模型;其次讨论了自回归预测原理和Kalman滤波预测的无偏性,并针对不同的通信模式提出不同的预测方法。理论分析和仿真结果均表明,基于Kalman滤波器的自回归预测值能很好地与理论值近似匹配,采用预测模型可以大大减少授权用户和认知用户的冲突,提高系统利用率。 展开更多
关键词 广播电视系统 自回归 KALMAN滤波 频谱空洞 认知无线电
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Path loss modelling and comparison based on the radio propagation measurement at 3.5GHz 被引量:4
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作者 王萍 Li Yingzhe +2 位作者 Chang Ruoting Sun Kun Xu Hui 《High Technology Letters》 EI CAS 2009年第3期272-276,共5页
Wideband IMT-Advanced mobile communication systems tend to operate in the high frequency bandsdue to a relatively large capacity available .Thus,Measurement and modelling methods of radio propaga-tion characteristics ... Wideband IMT-Advanced mobile communication systems tend to operate in the high frequency bandsdue to a relatively large capacity available .Thus,Measurement and modelling methods of radio propaga-tion characteristics are proposed for the field test of Chinese 4th generation(4G)trial system.The mea-surement system is established for 3 .5GHz based on the sophisticated measurement instruments and thevirtual instrument technology.The characteristic parameters of radio propagation such as path loss(PL)exponent and shadow fading standard deviation are extracted from measurement data,which result in thepath loss model finally.The comparisons with other existing international models results validate our mea-surement in terms of path loss model .Based on the analysis of the existing extension model assumed forthe microwave frequency at 3 .5GHz,we find that the Stanford University Interim(SUI)model fits verywell with the measurement result in the hotspot scenario,while the COST 231 model is closer to the mea-surement result in the suburban scenario.This result provides a measurement-based channel reference forthe development of the future IMT-Advanced systems in China. 展开更多
关键词 路径损耗模型 无线电传播 测量仪器 基础 移动通信系统 生态系统评估 虚拟仪器技术 斯坦福大学
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基于GNU Radio和USRP的未知信号检测技术研究 被引量:5
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作者 李国建 郝恒 《通信技术》 2017年第11期2610-2616,共7页
近两年,"黑广播"、伪基站等非法无线电信号,严重影响民航,诈骗人民财产安全。尽管无线电管理部门采取高压态势,但是技术更迭使这类设备愈加便宜和小型化,且可安装在高楼、大树等处,辐射远超国家标准,严重影响附近居民的身心... 近两年,"黑广播"、伪基站等非法无线电信号,严重影响民航,诈骗人民财产安全。尽管无线电管理部门采取高压态势,但是技术更迭使这类设备愈加便宜和小型化,且可安装在高楼、大树等处,辐射远超国家标准,严重影响附近居民的身心健康。以最新的软无平台——USRP+GNU Radio为架构基础,设计并实现以自动探测未知信号的系统,采用能量检测算法,实现了其对大功率信号检测的良好效果。系统能获得未知信号的相关参数,而后续研究可通过多点共同协作,计算未知信号的距离和方位,以便及时消除隐患,捍卫无线电空域安全。 展开更多
关键词 USRP GNU radio 能量检测法 自动探测
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Performance Analysis of Hybrid MAC Protocol for Cognitive Radio Networks
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作者 Nasir Faruk Mohammed I. Gumel +1 位作者 Abdulkarim A. Oloyode Adeseko A. Ayeni 《International Journal of Communications, Network and System Sciences》 2013年第1期18-28,共11页
The rapid growth in demand for broadband wireless services coupled with the recent developmental work on wireless communications technology and the static allocation of the spectrum have led to the artificial scarcity... The rapid growth in demand for broadband wireless services coupled with the recent developmental work on wireless communications technology and the static allocation of the spectrum have led to the artificial scarcity of the radio spectrum. The traditional command and control model (Static allocation) of spectrum allocation policy allows for severe spectrum underutilization. Spectrum allocated to TV operators can potentially be shared by wireless data services, either when the primary service is switched off or by exploiting spatial reuse opportunities. This paper describes a hybrid access scheme based on CSMA/CA and TDMA MAC protocols for use in the TV bands. The approach allows secondary users (SU) to operate in the presence of the primary users (PU) and the OPNET simulation and modelling software has been used to model the performance of the scheme. An analysis of the results shows that, the proposed schemes protect the primary user from harmful Interference from the secondary user. In terms of delay, it was found that packet arrival rates, data rates and the number of secondary users have significant effects on delay. 展开更多
关键词 Dynamic Spectrum Access (DSA) Optimized Network Engineering Tool (OPNET) tv WHITE Space COGNITIVE radio Networks Signal-To-Interference Ratio (SIR) Hybrid MAC
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Interference Mitigation MAC Protocol for Cognitive Radio Networks
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作者 Nasir Faruk Maaruf Ali Mohammed Ibrahim Gumel 《Wireless Engineering and Technology》 2012年第2期63-71,共9页
The growing demand for wireless services coupled with the limited availability of suitable electromagnetic spectrum is increasing the need for more efficient RF spectrum utilization. Spectrum allocated to TV operators... The growing demand for wireless services coupled with the limited availability of suitable electromagnetic spectrum is increasing the need for more efficient RF spectrum utilization. Spectrum allocated to TV operators can potentially be shared by wireless data services, either when the primary service is switched off or by exploiting spatial reuse opportunities. This paper describes a dynamic spectrum access scheme for use in the TV bands which uses cognitive radio techniques to determine the spectrum availability. The approach allows secondary users (SU) to operate in the presence of the primary users (PU) and the OPNET simulation and modelling software has been used to model the performance of the scheme. An analysis of the results shows that the proposed scheme protects the primary users from harmful interference from the secondary users. In comparison with the 802.11 MAC protocol, the scheme improves spectrum utilization by about 27% while limiting the interference imposed on the primary receiver. 展开更多
关键词 Dynamic Spectrum Access (DSA) Optimized Network Engineering Tool (OPNET) tv WHITE Space COGNITIVE radio Networks Signal-to-Interference Ratio (SIR)
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基于Helix Universal Server的网络电台的设计与实现
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作者 黄远辉 《电脑知识与技术》 2006年第12X期46-48,共3页
本文分析了网络电台的技术构成,从流媒体电台与电台网站两个方面分析整个网络电台的系统构成与设计,最后主要介绍基于Helix Universal Server的网络电台所用到的各种直播技术。
关键词 Helix universal Server ASP.net 流媒体 SMIL 网络电台
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A Routing Protocol for Enhanced Efficiency in Cognitive Radio Networks
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作者 Athina Bourdena George Mastorakis +1 位作者 Evangelos Pallis Georgios Kormentzas 《通讯和计算机(中英文版)》 2013年第5期675-685,共11页
关键词 无线电网络 路由协议 通信节点 模拟实验 信令机制 监管制度 绩效考核 仿真结果
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Mathematical Overview of Hypersphere World-Universe Model 被引量:6
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作者 Vladimir S. Netchitailo 《Journal of High Energy Physics, Gravitation and Cosmology》 2017年第3期415-437,共23页
The Hypersphere World-Universe Model (WUM) provides a mathematical framework that allows calculating the primary cosmological parameters of the World which are in good agreement with the most recent measurements and o... The Hypersphere World-Universe Model (WUM) provides a mathematical framework that allows calculating the primary cosmological parameters of the World which are in good agreement with the most recent measurements and observations. WUM explains the experimental data accumulated in the field of Cosmology and Astroparticle Physics over the last decades: the age of the World and critical energy density;the gravitational parameter and Hubble’s parameter;temperatures of the cosmic microwave background radiation and the peak of the far-infrared background radiation;the concentration of intergalactic plasma and time delay of Fast Radio Bursts. Additionally, the model predicts masses of dark matter particles, photons, and neutrinos;proposes new types of particle interactions (Super Weak and Extremely Weak);shows inter-connectivity of primary cosmological parameters of the World. WUM proposes to introduce a new fundamental parameter Q in the CODATA internationally recommended values. This paper is the summary of the mathematical results obtained in [1]-[4]. 展开更多
关键词 HYPERSPHERE World-universe Model Primary COSMOLOGICAL Parameters Medium of the World Macroobjects Structure Gravitoelectromagnetism Dark Matter Particles Intergalactic Plasma Microwave BACKGROUND RADIATION FAR-INFRARED BACKGROUND RADIATION Fast radio BURSTS Emergent Phenomena CODATA
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新文科视域下地方院校广播电视编导专业人才培养的转型与发展
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作者 黄斯文 尹睿 葛新 《上饶师范学院学报》 2023年第4期73-77,共5页
社会媒体产业结构发生巨变,高等教育掀起新文科建设的现代教育改革热潮,地方院校的广播电视编导专业人才培养转型发展问题日渐凸显。各地方院校需重新思考广播电视编导专业的学科定位,结合地方社会产业结构发展,形成区域优势,完成从“... 社会媒体产业结构发生巨变,高等教育掀起新文科建设的现代教育改革热潮,地方院校的广播电视编导专业人才培养转型发展问题日渐凸显。各地方院校需重新思考广播电视编导专业的学科定位,结合地方社会产业结构发展,形成区域优势,完成从“广播电视人才”向“新媒体内容创作人才”培养目标定位的转变,形成专业与地方协同育人策略,开拓一条新文科视域下的广播电视编导专业服务地方建设的应用型发展之路。 展开更多
关键词 新文科建设 地方院校 广播电视编导专业 人才培养 服务地方 转型发展
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面向国一流专业建设的政产学研协同育人路径研究--以广播电视工程专业为例
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作者 张赟 章化冰 +2 位作者 宋霄钰 陆琼 张久圆 《中国有线电视》 2023年第10期65-70,共6页
为推进广播电视工程国家级一流本科专业建设,提升人才培养质量,从政产学研协同的视角出发,分析如何在媒体深度融合背景下,培养符合广播电视和媒体行业发展需要的高素质人才。首先,介绍国家级一流本科专业建设的背景和目标,分析政产学研... 为推进广播电视工程国家级一流本科专业建设,提升人才培养质量,从政产学研协同的视角出发,分析如何在媒体深度融合背景下,培养符合广播电视和媒体行业发展需要的高素质人才。首先,介绍国家级一流本科专业建设的背景和目标,分析政产学研协同育人对传媒新工科人才培养的重要性;然后,指出当前广播电视工程专业在人才培养中存在的主要问题,并对政产学研协同育人的研究进展进行综述;最后,以广播电视工程专业为例,从专业优势与困境、实现路径的视角研究政产学研协同育人的实现机制和方法。 展开更多
关键词 广播电视工程 政产学研协同育人 新工科 媒体深度融合
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佛山电视塔供配电系统的设计与思考
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作者 李江山 《智能建筑电气技术》 2023年第1期100-102,共3页
本文基于佛山电视塔维修改造工程的电气系统设计工作,前期由于设计周期紧张,适逢《民用建筑电气设计标准》GB 51348—2019实施前夕,本项目的设计尚按照当时现行规范设计。现项目已完成,设计团队按照《民用建筑电气设计标准》的新要求,... 本文基于佛山电视塔维修改造工程的电气系统设计工作,前期由于设计周期紧张,适逢《民用建筑电气设计标准》GB 51348—2019实施前夕,本项目的设计尚按照当时现行规范设计。现项目已完成,设计团队按照《民用建筑电气设计标准》的新要求,从设计原有条件、业主需求、国家规范的要求等,梳理改造佛山电视塔的广播电视发射机房供配电系统、附加电击防护、航空障碍灯等方面的设计要点,回顾设计成果是否满足新标准的要求,并为后续设计工作积累经验。 展开更多
关键词 佛山电视塔 广播电视发射机房 供配电系统 安全 电击防护 航空障碍标志灯
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