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基于最优窗函数Gabor变换的变工况行星齿轮箱故障诊断 被引量:2
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作者 胡瑞杰 庞学博 +3 位作者 佘彩青 刘艾强 胡少梁 李宏坤 《风机技术》 2021年第2期79-90,共12页
强噪声背景下变工况行星齿轮箱振动信号具有非平稳、调制等特点,传统时频分析方法难以获得高时频分辨率的时频图像。本文提出一种分数域最优窗函数Gabor变换方法,利用分数阶傅里叶变换(Fractional Fourier Transform,FrFT)处理线性调频... 强噪声背景下变工况行星齿轮箱振动信号具有非平稳、调制等特点,传统时频分析方法难以获得高时频分辨率的时频图像。本文提出一种分数域最优窗函数Gabor变换方法,利用分数阶傅里叶变换(Fractional Fourier Transform,FrFT)处理线性调频信号的优越性,在分数域优化时频窗函数,获得最小广义时间带宽积原则下的最优窗函数,从而获得高时频分辨率、高能量聚集性的时频图像,且抑制背景噪声的干扰。通过仿真信号与行星齿轮箱故障信号分析,验证了本文方法在变工况行星齿轮箱故障诊断中的可行性与优越性。 展开更多
关键词 行星齿轮箱 故障诊断 时频变换 分数阶傅里叶变换 最优窗函数
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Study on the Effect of Ginaton on Reducing Cerebral Vasospasm and Early Brain Injury after Hemorrhagic Stroke by Inhibiting Inflammatory Response
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作者 xue-bo pang Xiao-Lin Zhang +2 位作者 Mei-Rong Wang Ying Yuan Xiao Zhang 《World Journal of Traditional Chinese Medicine》 CAS CSCD 2024年第1期33-39,共7页
Objective:The objective of this study was to investigate the effects and possible mechanisms of action of ginseng on cerebral vasospasm and early brain injury(EBI)following hemorrhagic stroke.Materials and Methods:Spr... Objective:The objective of this study was to investigate the effects and possible mechanisms of action of ginseng on cerebral vasospasm and early brain injury(EBI)following hemorrhagic stroke.Materials and Methods:Sprague-Dawley(SD)rats(n=48)were randomly divided into sham operation(sham group),subarachnoid hemorrhage(SAH)model(SAH group),normal saline(NS group),and Ginaton(Extract of Ginkgo Biloba Leaves Drops)intervention(gin group)groups.MCP-1 m RNA and tumor necrosis factor levels were detected using reverse transcription-polymerase chain reaction.The relative expression of m RNA was detected by Western blotting.Results:(1)Compared with the sham group,the SAH,NS,and gin groups had different degrees of neurological dysfunction.Compared with the SAH and NS groups,the neurological deficits in the gin group were significantly improved(P<0.05).(2)Compared with the sham group,the relative expression levels of MCP-1 m RNA in the SAH,NS,and gin groups were 5.1±0.9,3.4±0.6,and 2.5±0.4,respectively;the relative expression levels of m RNA were 13.3±2.4,11.2±1.8,and 3.8±0.6,respectively.(3)The apoptosis rates of brain tissue in the sham,SAH,NS,and gin groups were 4.8±0.7,54.2±10.3,50.1±7.4,and 28.4±4.5,respectively.(4)Western blot showed that the relative expression levels of toll-like receptor-4(TLR-4)protein in the sham,SAH,NS,and gin groups were 0.29±0.03,0.87±0.15,0.65±0.13,and 0.41±0.17,respectively;the relative expression levels of B protein were 0.21±0.04,0.96±0.14,0.73±0.18,and 0.30±0.05,respectively.Gin treatment could inhibit TLR-4 and nuclear factor-κB(NF-κB)protein expression.Conclusions:Dona tablets may inhibit activation of the NF-κB signaling pathway,and SAH-induced inflammatory response,so as to reduce cerebral vasospasm and EBI. 展开更多
关键词 Cerebral hemorrhage early brain injury GINATON neurological deficit nuclear factor-κB
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