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采用振动检验法评定汽轮发电机定子铁心弹性隔振系统状态
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作者 Куэнецов Д.В. 邱建甫(译) 《国外大电机》 2010年第4期47-54,共8页
本文指出了单机容量200MW及以上的汽轮发电机定子铁心隔振系统组件经常损坏,表现在:(1)铁心本体和隔振系统支承构件(拉紧式定位筋)相结合的面机械磨损;(2)焊缝出现裂纹;(3)螺母旋松和拉紧式定位筋颈部断裂,发电机内膛被机... 本文指出了单机容量200MW及以上的汽轮发电机定子铁心隔振系统组件经常损坏,表现在:(1)铁心本体和隔振系统支承构件(拉紧式定位筋)相结合的面机械磨损;(2)焊缝出现裂纹;(3)螺母旋松和拉紧式定位筋颈部断裂,发电机内膛被机械磨损物堵塞。这些是由结构上的如下缺点所造成的:(1)定子铁心轭部抗弯刚度低;(2)铁心本体隔振系统各构件的强度不够;(3)铁心和与之结合的构件共振。着重论及了检验运行中的汽轮发电机隔振系统状况和检修期间的定子铁心隔振系统诊断。 展开更多
关键词 汽轮发电机 定子铁心 弹性隔振系统 振动检验
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时间序列线性/非线性在线检验
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作者 朱向阳 钟秉林 +1 位作者 贾民平 黄仁 《振动工程学报》 EI CSCD 1997年第1期76-80,共5页
给出了AR模型参数二阶矩Yule-Walker方程和四阶矩Yule-Walker方程估计的等价最小二乘估计,以及二阶矩和四阶矩Yule-Walker方程参数估计的递推算法,在此基础上提出一种时间序列的线性/非线性在线... 给出了AR模型参数二阶矩Yule-Walker方程和四阶矩Yule-Walker方程估计的等价最小二乘估计,以及二阶矩和四阶矩Yule-Walker方程参数估计的递推算法,在此基础上提出一种时间序列的线性/非线性在线检验方法。 展开更多
关键词 时间序列 线性检验 非线性检验 振动检验 在线
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Direct detection of oxygen free radicals produced in the viscera of burned rats using electron paramagnetic resonance spectroscopy 被引量:2
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作者 路卫 陈玉琳 夏照帆 《Chinese Journal of Traumatology》 CAS 2002年第2期118-120,共3页
To detect superoxide anion (O - 2 ) signals in the heart, liver, lung and kidney tissues after burns. Methods: Twenty four male rats were randomized into 4 groups. The rats of experimental groups were immersed in 100... To detect superoxide anion (O - 2 ) signals in the heart, liver, lung and kidney tissues after burns. Methods: Twenty four male rats were randomized into 4 groups. The rats of experimental groups were immersed in 100℃ water for 15 seconds and 25% third degree burn was created. Thoracotomy or laparotomy was performed at 5, 10, 15, 20 and 30 minutes after burn, and specimens of the heart, lung, liver kidney were obtained for burned rats. The specimens were then preserved in liqu id nitrogen for cryo preservation and detected immediately using EPR. Results: The signals of superoxide O radical appeared in the he art, lung, 1iver and kidney specimens 10 15 minutes after burn. Conclusions: There is a direct evidence of oxygen free radicals (OFRs) injury to viscera of burned rats between 10 15 minutes after burn. 展开更多
关键词 BURNS Oxygen free radicals Electron paramagnetic r esonance
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State Inspection for Transmission Lines Based on Independent Component Analysis
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作者 任丽佳 江秀臣 +1 位作者 盛戈嗥 杨巍巍 《Journal of Shanghai Jiaotong university(Science)》 EI 2009年第2期129-132,共4页
Monitoring transmission towers is of great importance to prevent severe thefts on them and ensure the reliability and safety of the power grid operation.Independent component analysis(ICA) is a method for finding unde... Monitoring transmission towers is of great importance to prevent severe thefts on them and ensure the reliability and safety of the power grid operation.Independent component analysis(ICA) is a method for finding underlying factors or components from multivariate statistical data based on dimension reduction methods,and it is applicable to extract the non-stationary signals.FastICA based on negentropy is presented to effectively extract and separate the vibration signals caused by human activity in this paper.A new method combined empirical mode decomposition(EMD) technique with the adaptive threshold method is applied to extract the vibration pulses,and suppress the interference signals.The practical tests demonstrate that the method proposed in the paper is effective in separating and extracting the vibration signals. 展开更多
关键词 state inspection transmission lines independent component analysis (ICA) NEGENTROPY adaptive threshold empirical mode decomposition (EMD)
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