排序方式: 共有188条查询结果,搜索用时 15 毫秒
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针对CATV/HFC反向通道噪声监测及抑制问题进行了研究,以TMS320C672BDSP为核心,ARM7TMDI为主要芯片,设计了多光点反向信号混合控制器,建立了CATV/HFC反向通道噪声监测及抑制系统.对反向通道信号进行实时采集和处理表明,该系统具有很高的反向噪声频谱采集速度,可"无缝地"捕捉隐匿于反向服务载波背后的噪声.且系统能自动报警和自动关闭噪声来源通道. 相似文献
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Traditional dynamic stability analyses of the rolling projectiles are mainly based on solving the systems' transfer functions or angular motion' s homogeneous equations to obtain their charac- teristic roots. The solving processes of these methods are complex and lacking further analysis of the results. To solve this problem, Routh stability criterion is introduced to determine the stability of rolling missiles based on the transfer function model, and an important advantage of this method is that it is unnecessary to solve the system' s characteristic equation. Rotational speed ranges satisfy- ing the dynamic stability of rolling projectiles with four different characteristics are acquired, and the correctness of analysis results is verified by computing the system' s root locus. The analysis results show that the relation between stability and rotational speed for static stable missiles is opposite to that for spin-stabilized projectiles, and the relative size of gyroscopic effect and Magnus effect has an extremely important influence on the trend of the stability of the system with increasing rotational speed. 相似文献
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工业锅炉节能要靠合理的设备选用和科学的运行技术实现。从设备选型、燃料配备、燃烧控制等方面论述了锅炉的节能技术,对锅炉的合理选用和运行管理都有指导作用。 相似文献
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基于单/双同步坐标系的软件锁相环建模和仿真 总被引:6,自引:0,他引:6
针对风力发电机组的低电压穿越控制要求,有必要研究适应电网电压平衡和不平衡情况下的电压快速准确检测方法.在分析单/双同步坐标轴系软件锁相环工作原理的基础上,基于Matlab/Simulink软件平台,分别建立了单同步坐标系软件锁相环(SSRF-SPLL)和双同步坐标系的解耦软件锁相环(DDSRF-SPLL)的仿真模型,并针对电网电压理想工况和电网电压三相不平衡情况,对单/双同步坐标轴系下软件锁相环的运行性能进行了仿真比较.结果表明,SSRF-SPLL仅适合电压理想正常工况下的监测,而DDSRF-SPLL不仅适合电压理想工况,而且无论是电压单相或两相跌落等情况也能快速地实现电压幅值、相位和频率的监测. 相似文献