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一种基于能零积的改进端点检测算法
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作者 韦金泉 罗丽燕 +3 位作者 王玫 刘争红 何锐彬 莫清麟 《计算机应用与软件》 北大核心 2024年第7期215-221,共7页
针对基于短时能量和短时过零率的传统端点检测算法在信噪比低于10 dB时其准确性明显下降的问题,提出一种基于声谱图特征增强的能零积端点检测改进算法。首先,对音频信号进行谱减法降噪,提升信号的信噪比;其次,依次对声谱图进行腐蚀、二... 针对基于短时能量和短时过零率的传统端点检测算法在信噪比低于10 dB时其准确性明显下降的问题,提出一种基于声谱图特征增强的能零积端点检测改进算法。首先,对音频信号进行谱减法降噪,提升信号的信噪比;其次,依次对声谱图进行腐蚀、二值化和膨胀处理,以实现声谱图特征增强;最后,提取能零积特征,并利用双阈值端点检测算法对音频信号进行端点检测。实验结果表明,该算法在不同信噪比条件下可以有效捕获有环境异常音片段,具有良好的鲁棒性。 展开更多
关键词 端点检测 能零积 低信噪比 声谱图 特征增强
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Light emission of double-walled carbon nanotube filaments doped with yttrium and europium 被引量:1
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作者 SHU QinKe WANG KunLin +7 位作者 wei jinquan ZHU Hongwei LI XinMing CHEN Xi JIA Yi GUI XuChun XU ErYang WU DeHai 《Science China(Technological Sciences)》 SCIE EI CAS 2009年第1期252-255,共4页
As the potential applications of carbon nanotubes in the field of electroluminescence, elements yttrium and europium were introduced to modify the emission properties of double-walled carbon nanotubes (DWNTs) to obtai... As the potential applications of carbon nanotubes in the field of electroluminescence, elements yttrium and europium were introduced to modify the emission properties of double-walled carbon nanotubes (DWNTs) to obtain higher efficacy and other properties. The light emission spectrum of the Y-Eu-doped DWNT filament is suppressed in the near-infrared range, while enhanced in the mid-infrared range. The doped DWNT filament can reach higher efficacy than that of the pure DWNT filament at the same input power and can work stably as long as 5000 h at 12 V. These filaments could be useful for the light sources with special functions, such as infrared light sources operated at low input power. 展开更多
关键词 carbon NANOTUBES ELECTROLUMINESCENCE EFFICACY YTTRIUM EUROPIUM
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Luminescence of carbon nanotube bulbs
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作者 LI ChuanGang WANG KunLin +7 位作者 wei jinquan wei BingQing ZHU Hongwei WANG ZhiCheng LUO JianBin LIU WenJin ZHENG MingXin WU DeHai 《Chinese Science Bulletin》 SCIE EI CAS 2007年第1期113-117,共5页
Carbon nanotube (CNT) bulbs made of decimeter-scale double-walled carbon nanotube (DWCNT) strands and films were fabricated and their luminescence properties, including the lighting efficiency, voltage-current relatio... Carbon nanotube (CNT) bulbs made of decimeter-scale double-walled carbon nanotube (DWCNT) strands and films were fabricated and their luminescence properties, including the lighting efficiency, voltage-current relation and thermal stability were investigated. The results show that the DWCNT bulb has a comparable spectrum of visible light with tungsten bulb and its average efficiency is 40% higher than that of a tungsten filament at the same temperature (1400―2300 K). The nanotube filaments show both resistance and thermal stability over a large temperature region. No obvious damage was found for a nanotube bulb illuminating at 2300 K for more than 24 hours in vacuum. 展开更多
关键词 碳纳米管 灯管 发光性 电子产品
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