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一种分析变压器噪声异常原因的简易方法 被引量:2
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作者 朱玲 李春先 《机电工程技术》 2021年第5期262-264,共3页
变压器在现场运行过程中出现噪声异常是一个常见问题,需要快速判断引起噪声异常的可能原因。变压器现场运行噪声受负荷大小、负荷性质、中性点直流注入、电压谐波和基础平整度等诸多因素的影响,由于不同原因引起的噪声异常在频谱特性具... 变压器在现场运行过程中出现噪声异常是一个常见问题,需要快速判断引起噪声异常的可能原因。变压器现场运行噪声受负荷大小、负荷性质、中性点直流注入、电压谐波和基础平整度等诸多因素的影响,由于不同原因引起的噪声异常在频谱特性具有不同的特征,可通过提取这些噪声的频谱特征值判断引起噪声异常的原因。介绍一种通过对变压器现场录制噪声导进音频软件中,对音频进行频谱分析的方法,初步判断造成变压器噪声异常的可能原因,并提供一些可能的解决措施。 展开更多
关键词 变压器噪声 频谱分析 现场运行噪声
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沥青路面降噪性能研究综述 被引量:42
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作者 苗英豪 王秉纲 《中外公路》 北大核心 2006年第4期65-68,共4页
该文从现场噪声测试入手,对现阶段国内外沥青路面降噪性能的研究成果进行了综述。研究表明,车速相对较高、交通组成中卡车相对较少的路段,路面材料的合理选择对交通噪声的降低较明显。普遍认为开级配抗滑磨耗层(OGFC)和沥青橡胶路面具... 该文从现场噪声测试入手,对现阶段国内外沥青路面降噪性能的研究成果进行了综述。研究表明,车速相对较高、交通组成中卡车相对较少的路段,路面材料的合理选择对交通噪声的降低较明显。普遍认为开级配抗滑磨耗层(OGFC)和沥青橡胶路面具有优良的降噪性能;同种类型的沥青混合料,公称最大粒径越小,降噪性能越好。因而有必要对沥青玛蹄脂碎石(SMA)路面以及不同级配类型沥青橡胶路面的降噪性能进行系统深入的研究。 展开更多
关键词 沥青路面 降噪性能 现场噪声测试
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宽频带阻抗复合消声器的设计和应用 被引量:2
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作者 卜志威 《声学技术》 CSCD 2001年第3期140-141,共2页
根据风机房进风口噪声的频谱特征和现场噪声的分析 ,给出了低频、宽带阻抗复合消声器的设计方法 。
关键词 宽频带阻抗复合消声器 设计 频谱特征 现场噪声 消声 风机房 进风口噪声
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Traffic Noise Pollution: Spectra Characteristics and Windows Sound Insulation in Laboratory and Field Measurements 被引量:2
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作者 C. Buratti E. Moretti 《Journal of Environmental Science and Engineering》 2010年第12期28-36,共9页
The traffic spectra influence on indoor noise through windows is evaluated with laboratory and field measurements. Different traffic noise spectra were registered and reproduced, simulating the outdoor traffic conditi... The traffic spectra influence on indoor noise through windows is evaluated with laboratory and field measurements. Different traffic noise spectra were registered and reproduced, simulating the outdoor traffic conditions through different windows. Spectrum adaptation terms for the recorded spectra were different from the ones obtained from the Standards, showing that Normative gives a safe evaluation of the Weighted Sound Insulation Index. In field measurements, the level abatements calculated from the Facade Acoustic Insulation Index corrected with the adaptation terms shows that the ones from the Standard do not give a good approximation, while if the level abatements is calculated using the adaptation terms from the registered spectra, a more reliable approximation is achieved. Furthermore, comparing the level abatements for two windows having both Rw equal to 41 dB, very different values were obtained at different frequencies; therefore to characterize acoustic performances of windows, sound insulation curves are also needed. The correlation between the mean difference between adaptation terms calculated from the standard and the one between abatements obtained with pink noise and the ones obtained with the registered spectra is good, but different for road traffic and trains. In both, the difference diminishes when the difference between the abatements increases. 展开更多
关键词 Traffic noise pollution traffic noise spectra spectrum adaptation terms level abatements
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Bit-stream linear artificial neural networks based on Sigma-delta modulation 被引量:2
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作者 梁勇 Wang Zhigong +1 位作者 Meng Qiao Guo Xiaodan 《High Technology Letters》 EI CAS 2012年第2期120-123,共4页
To solve the excessive huge scale problem of the traditional multi-bit digital artificial neural networks (ANN) hardware implementation methods, a bit-stream ANN construction method based on direct sigma-delta (Z-A... To solve the excessive huge scale problem of the traditional multi-bit digital artificial neural networks (ANN) hardware implementation methods, a bit-stream ANN construction method based on direct sigma-delta (Z-A) signal processing is presented. The bit-stream adder, multiplier and fully digital X-A modulator used in the bit-stream linear ANN are implemented in a field programmable gate array (FPGA). A bit-stream linear ANN based on these bit-stream modules is presented and implemented. To verify the function and performance of the bit-stream linear ANN, the bit-stream adaptive predictor and the bit-stream adaptive noise cancellation system are presented. The predicted result of the bit-stream adaptive predictor is very close to the desired signal. Also, the bit-stream adaptive noise cancellation system removes the electric power noise effectively. 展开更多
关键词 bit-stream artificial neuron SIGMA-DELTA linear artificial neural networks field programmablegate array (FPGA)
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