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90% <i>SNR</i>Improvement with Multi-Port Hall Plates 认领
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作者 Udo Ausserlechner 《应用数学与应用物理(英文)》 2020年第8期1568-1605,共38页
For Hall plates, the ratio of signal over thermal noise is determined by material properties, thickness, layout geometry, magnetic field, and the electric power at which the plate is operated. For traditional Hall pla... For Hall plates, the ratio of signal over thermal noise is determined by material properties, thickness, layout geometry, magnetic field, and the electric power at which the plate is operated. For traditional Hall plates with four contacts, the optimum choice is a symmetrical device with medium-sized contacts. This paper shows that the signal-to-noise-ratio (<em>SNR</em>) can be further increased by up to 90% for Hall plates with more than four contacts. Supply currents flow through several pairs of contacts, while a signal conditioning circuit taps output voltages at all pairs of contacts and sums them up. We compute the total thermal noise of the sum of correlated noise voltages and relate it to the total magnetic sensitivity. We also prove that for electrically linear devices a spinning current scheme cancels out zero point errors (offset errors) in a strict sense. All our investigations use the definite resistance matrix of multi-port Hall plates. We develop an analytical theory based on recent advances in the theory of Hall plates, and then we compute the integrals and matrices numerically for symmetrical Hall plates with six to 40 contacts. We also present measurements in accordance with our theory. 展开更多
关键词 Multi-Port Hall Plates Noise Correlation Noise Efficiency Signal to Noise Ratio Spinning Scheme Thermal Noise Toeplitz Matrix
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Noises and Signal-to-Noise Ratio of Nanosize EIS and ISFET Biosensors 认领
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作者 Lusine Gasparyan Ilya Mazo +1 位作者 Vahan Simonyan Ferdinand Gasparyan 《生物物理学期刊(英文)》 2020年第1期1-12,共12页
The results of comparative theoretical analyzes of the behavior of internal low-frequency noises, signal-to-noise ratio and sensitivity to DNA molecules for EIS and ISFET based nanosize biosensors are presented. It is... The results of comparative theoretical analyzes of the behavior of internal low-frequency noises, signal-to-noise ratio and sensitivity to DNA molecules for EIS and ISFET based nanosize biosensors are presented. It is shown that EIS biosensor is more sensitive to the presence of DNA molecules in aqueous solution than ISFET sensor. Internal electrical noises level decreases with the increase of concentration of DNA molecules in aqueous solution. In the frequency range 10&minus;3 - 103 Hz noises level for EIS sensor about in three orders is higher than for ISFET sensor. In the other hand, signal-to-noise ratio for capacitive EIS biosensor is much higher than for ISFET sensor. 展开更多
关键词 BIOSENSOR Noise Sensitivity SIGNAL-TO-NOISE Ratio
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A novel noise reduction technique for underwater acoustic signals based on complete ensemble empirical mode decomposition with adaptive noise,minimum mean square variance criterion and least mean square adaptive filter 认领
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作者 Yu-xing Li Long Wang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2020年第3期543-554,共12页
Underwater acoustic signal processing is one of the research hotspots in underwater acoustics.Noise reduction of underwater acoustic signals is the key to underwater acoustic signal processing.Owing to the complexity ... Underwater acoustic signal processing is one of the research hotspots in underwater acoustics.Noise reduction of underwater acoustic signals is the key to underwater acoustic signal processing.Owing to the complexity of marine environment and the particularity of underwater acoustic channel,noise reduction of underwater acoustic signals has always been a difficult challenge in the field of underwater acoustic signal processing.In order to solve the dilemma,we proposed a novel noise reduction technique for underwater acoustic signals based on complete ensemble empirical mode decomposition with adaptive noise(CEEMDAN),minimum mean square variance criterion(MMSVC) and least mean square adaptive filter(LMSAF).This noise reduction technique,named CEEMDAN-MMSVC-LMSAF,has three main advantages:(i) as an improved algorithm of empirical mode decomposition(EMD) and ensemble EMD(EEMD),CEEMDAN can better suppress mode mixing,and can avoid selecting the number of decomposition in variational mode decomposition(VMD);(ii) MMSVC can identify noisy intrinsic mode function(IMF),and can avoid selecting thresholds of different permutation entropies;(iii) for noise reduction of noisy IMFs,LMSAF overcomes the selection of deco mposition number and basis function for wavelet noise reduction.Firstly,CEEMDAN decomposes the original signal into IMFs,which can be divided into noisy IMFs and real IMFs.Then,MMSVC and LMSAF are used to detect identify noisy IMFs and remove noise components from noisy IMFs.Finally,both denoised noisy IMFs and real IMFs are reconstructed and the final denoised signal is obtained.Compared with other noise reduction techniques,the validity of CEEMDAN-MMSVC-LMSAF can be proved by the analysis of simulation signals and real underwater acoustic signals,which has the better noise reduction effect and has practical application value.CEEMDAN-MMSVC-LMSAF also provides a reliable basis for the detection,feature extraction,classification and recognition of underwater acoustic signals. 展开更多
关键词 Underwater acoustic signal Noise reduction Empirical mode decomposition(EMD) Ensemble EMD(EEMD) Complete EEMD with adaptive noise(CEEMDAN) Minimum mean square variance criterion(MMSVC) Least mean square adaptive filter(LMSAF) Ship-radiated noise
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文章速递Error suppression techniques for energy-efficient high-resolution SAR ADCs 认领
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作者 Jiaxin Liu Xiyuan Tang +4 位作者 Linxiao Shen Shaolan Li Zhelu Li Wenjuan Guo Nan Sun 《半导体学报:英文版》 EI CAS CSCD 北大核心 2020年第11期31-40,共10页
The successive approximation register(SAR)is one of the most energy-efficient analog-to-digital converter(ADC)architecture for medium-resolution applications.However,its high energy efficiency quickly diminishes when ... The successive approximation register(SAR)is one of the most energy-efficient analog-to-digital converter(ADC)architecture for medium-resolution applications.However,its high energy efficiency quickly diminishes when the target resolution increases.This is because a SAR ADC suffers from several major error source,including the sampling kT/C noise,the comparator noise,and the DAC mismatch.These errors are increasing hard to address in high-resolution SAR ADCs.This paper reviews recent advances on error suppression techniques for SAR ADCs,including the sampling kT/C noise reduction,the noise-shaping(NS)SAR,and the mismatch error shaping(MES).These techniques aim to boost the resolution of SAR ADCs while maintaining their superior energy efficiency. 展开更多
关键词 SAR ADC kT/C noise cancellation noise shaping(NS) mismatch error shaping(MES)
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文章速递带式输送机的降噪措施及验证试验 认领
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作者 冯文博 《陕西煤炭》 2020年第6期20-26,共7页
为了降低矿用带式输送机运行过程的噪声,采取适当增加齿数、压力角、螺旋角、齿宽和精度等级,选用斜齿轮,增大齿面的接触面积,增大齿面啮合接触线长度,避免间断从而产生冲击振动引起的噪声。将带式输送机中间段看作线声源,推导出输送机... 为了降低矿用带式输送机运行过程的噪声,采取适当增加齿数、压力角、螺旋角、齿宽和精度等级,选用斜齿轮,增大齿面的接触面积,增大齿面啮合接触线长度,避免间断从而产生冲击振动引起的噪声。将带式输送机中间段看作线声源,推导出输送机安装的安全卫生距离,在此距离下村庄居民区的噪声符合标准;通过研究高分子材料吸声原理,对输送带进行三维建模及模态分析,探讨了发生共振的可能。采用高分子托辊降噪理论进行试验验证,证明该措施可有效降低噪声;在卸料部位,料斗内设多级溜板结构,料斗金属面内侧镶耐磨橡胶面,可使卸料部噪声约降低12 dB(A)。 展开更多
关键词 带式输送机 噪声 高分子材料 降噪
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文章速递浦东机场卫星厅空气处理机组噪声控制措施应用分析 认领
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作者 吴极 《工程建设与设计》 2020年第23期70-72,共3页
在浦东机场卫星厅中,有部分空调机房紧邻旅客候机区。论文根据设计规范的要求,分析了该部分空调机房内的空气处理机组的噪声源,并结合多种消声控制措施对空气处理机组进行消声设计:通过样机实测,空气处理机组的送、回风口噪声均满足设... 在浦东机场卫星厅中,有部分空调机房紧邻旅客候机区。论文根据设计规范的要求,分析了该部分空调机房内的空气处理机组的噪声源,并结合多种消声控制措施对空气处理机组进行消声设计:通过样机实测,空气处理机组的送、回风口噪声均满足设计要求。 展开更多
关键词 空气处理机组 噪声 机场 消声
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Monitoring of velocity changes based on seismic ambient noise: A brief review and perspective 认领
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作者 Qing-Yu Wang HuaJian Yao 《地球与行星物理:英文版》 CSCD 2020年第5期532-542,共11页
Over the past two decades,the development of the ambient noise cross-correlation technology has spawned the exploration of underground structures.In addition,ambient noise-based monitoring has emerged because of the f... Over the past two decades,the development of the ambient noise cross-correlation technology has spawned the exploration of underground structures.In addition,ambient noise-based monitoring has emerged because of the feasibility of reconstructing the continuous Green’s functions.Investigating the physical properties of a subsurface medium by tracking changes in seismic wave velocity that do not depend on the occurrence of earthquakes or the continuity of artificial sources dramatically increases the possibility of researching the evolution of crustal deformation.In this article,we outline some state-of-the-art techniques for noise-based monitoring,including moving-window cross-spectral analysis,the stretching method,dynamic time wrapping,wavelet cross-spectrum analysis,and a combination of these measurement methods,with either a Bayesian least-squares inversion or the Bayesian Markov chain Monte Carlo method.We briefly state the principles underlying the different methods and their pros and cons.By elaborating on some typical noisebased monitoring applications,we show how this technique can be widely applied in different scenarios and adapted to multiples scales.We list classical applications,such as following earthquake-related co-and postseismic velocity changes,forecasting volcanic eruptions,and tracking external environmental forcing-generated transient changes.By monitoring cases having different targets at different scales,we point out the applicability of this technology for disaster prediction and early warning of small-scale reservoirs,landslides,and so forth.Finally,we conclude with some possible developments of noise-based monitoring at present and summarize some prospective research directions.To improve the temporal and spatial resolution of passive-source noise monitoring,we propose integrating different methods and seismic sources.Further interdisciplinary collaboration is indispensable for comprehensively interpreting the observed changes. 展开更多
关键词 ambient noise correlation noise-based monitoring seismic wave velocity changes the evolution of physical properties of the crust
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变速器设计初期降低其噪音的方法探讨 认领
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作者 张海明 《机械管理开发》 2020年第9期86-87,93,共3页
变速器工作时发出噪音的大小是考核其自身性能的一项重要指标,噪音大严重影响变速器、整车的整体性能。通过分析组成变速器的齿轮、壳体、轴承、润滑油、螺栓的作用,分析在设计初期如何合理规避甚至解决噪音大的问题。
关键词 噪音 变速器设计 降噪
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高温高压管路疏水阀蒸汽排放过程中的三级降噪治理 认领
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作者 代佳雨 谢尧尧 +2 位作者 张建明 刘琦 赵强 《石油化工安全环保技术》 CAS 2020年第1期60-62,I0004,共4页
高温高压蒸汽在通过疏水阀排放的过程中会产生大分贝噪音,对整个厂区的工作环境影响较大,不利于职工保持良好心态,容易导致安全事故的发生。介绍了高温高压蒸汽通过疏水阀进行排放过程中产生的大分贝噪音的降噪处理装置及注意事项,通过... 高温高压蒸汽在通过疏水阀排放的过程中会产生大分贝噪音,对整个厂区的工作环境影响较大,不利于职工保持良好心态,容易导致安全事故的发生。介绍了高温高压蒸汽通过疏水阀进行排放过程中产生的大分贝噪音的降噪处理装置及注意事项,通过相变法、小孔变频方法及多层级扩散等方法对噪音进行处理,使排放过程中的噪音大幅度降低,可基本满足工作环境需要。 展开更多
关键词 高温高压蒸汽 疏水阀 噪音 降噪
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跨座式单轨交通运营期噪声影响与防治措施研究 认领
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作者 贾凡 《山西交通科技》 2020年第1期91-93,共3页
跨座式单轨交通运营期噪声对声环境影响不可避免,但跨座式单轨交通项目与传统交通项目噪声影响程度及防治措施不同,以重庆轨道交通二号线延伸段为例,通过现场调查、实际监测、类比分析等研究方法,得出了以下结论:跨座式单轨交通噪声影... 跨座式单轨交通运营期噪声对声环境影响不可避免,但跨座式单轨交通项目与传统交通项目噪声影响程度及防治措施不同,以重庆轨道交通二号线延伸段为例,通过现场调查、实际监测、类比分析等研究方法,得出了以下结论:跨座式单轨交通噪声影响远小于传统交通项目,跨座式单轨交通噪声防治措施采取以充气轮胎、齿形钢板嵌接式伸缩缝等主动降噪更为有效,可满足噪声防治要求。 展开更多
关键词 跨座式单轨交通 运营期 噪声 监测 主动降噪 措施
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摩托车制动噪音改进分析 认领
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作者 邓疆 刘权 《摩托车技术》 2020年第7期44-46,共3页
摩托车和轻便摩托车制动时产生的噪音问题在市场投诉多,成功解决案例很少。制动噪音产生复杂多样,涉及整车质量分配、制动系统及相关零部件的布置、结构、材料、刚度、硬度、尺寸、公差等多个方面的设计与验证。因此困扰着摩托车制造企... 摩托车和轻便摩托车制动时产生的噪音问题在市场投诉多,成功解决案例很少。制动噪音产生复杂多样,涉及整车质量分配、制动系统及相关零部件的布置、结构、材料、刚度、硬度、尺寸、公差等多个方面的设计与验证。因此困扰着摩托车制造企业对该问题的有效、快速解决。本文以解决一个车型制动噪音成功实例过程展开叙述,来寻找解决制动噪音的通用思路和基本方向。 展开更多
关键词 刚度 共振 噪音 中低频音 结构
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Noise in nanopore sensors: Sources, models, reduction, and benchmarking 认领
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作者 Shengfa Liang Feibin Xiang +4 位作者 Zifan Tang Reza Nouri Xiaodong He Ming Dong Weihua Guan 《纳米技术与精密工程(英文)》 EI CAS CSCD 2020年第1期9-17,共9页
Label-free nanopore sensors have emerged as a new generation technology of DNA sequencing and have been widely used for single molecule analysis.Since the firstα-hemolysin biological nanopore,various types of nanopor... Label-free nanopore sensors have emerged as a new generation technology of DNA sequencing and have been widely used for single molecule analysis.Since the firstα-hemolysin biological nanopore,various types of nanopores made of different materials have been under extensive development.Noise represents a common challenge among all types of nanopore sensors.The nanopore noise can be decomposed into four components in the frequency domain(1/f noise,white noise,dielectric noise,and amplifier noise).In this work,we reviewed and summarized the physicalmodels,origins,and reduction methods for each of these noise components.For the first time,we quantitatively benchmarked the root mean square(RMS)noise levels for different types of nanopores,demonstrating a clear material-dependent RMS noise.We anticipate this review article will enhance the understanding of nanopore sensor noises and provide an informative tutorial for developing future nanopore sensors with a high signal-to-noise ratio. 展开更多
关键词 Noise NANOPORE Model Material Noise REDUCTION
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Spatial and temporal white noises under sublinear G-expectation 认领
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作者 Xiaojun Ji Shige Peng 《中国科学:数学英文版》 SCIE CSCD 2020年第1期61-82,共22页
Under the framework of sublinear expectation,we introduce a new type of G-Gaussian random fields,which contains a type of spatial white noise as a special case.Based on this result,we also introduce a spatial-temporal... Under the framework of sublinear expectation,we introduce a new type of G-Gaussian random fields,which contains a type of spatial white noise as a special case.Based on this result,we also introduce a spatial-temporal G-white noise.Different from the case of linear expectation,in which the probability measure needs to be known,under the uncertainty of probability measures,spatial white noises are intrinsically different from temporal cases. 展开更多
关键词 SUBLINEAR EXPECTATION G-Brownian motion G-Gaussian random field G-white noise SPATIAL and temporal WHITE noise
株洲市噪声作业工人听力监测分析 认领
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作者 杨书 胡双球 +3 位作者 黄微 朱新河 孙康 王鑫 《中华劳动卫生职业病杂志》 CAS CSCD 北大核心 2020年第3期227-231,共5页
目的了解噪声作业工人听力损失现状,为制定有效的预防控制策略提供科学依据。方法于2018年1月1日至10月31日,通过作业场所职业病危害申报与备案管理系统和职业健康检查系统,收集株洲市136家企业7806名噪声作业工人的基本信息和体检信息... 目的了解噪声作业工人听力损失现状,为制定有效的预防控制策略提供科学依据。方法于2018年1月1日至10月31日,通过作业场所职业病危害申报与备案管理系统和职业健康检查系统,收集株洲市136家企业7806名噪声作业工人的基本信息和体检信息以及企业行业、类型、规模等相关信息,采用χ^2检验对辖区内噪声作业工人的职业健康监护数据和企业信息进行分析。结果株洲市7806名噪声作业工人年龄为(36.1±9.3)岁,工龄为7.0(3.0,11.0)年;检出听力损失工人1270人,检出率为16.27%;疑似职业性噪声聋51人,检出率为0.65%;噪声聋1人,检出率为0.01%。男性听力损失检出率明显高于女性,听力损失和疑似职业性噪声聋检出率均随着年龄和工龄的增加而增加(P<0.05);不同工种工人听力损失和疑似职业性噪声聋检出率差异均有统计学意义(P<0.05);不同行业、企业规模噪声作业工人听力损失检出率差异均有统计学意义(P<0.05),非金属矿采选行业工人的听力损失检出率较高(33.33%,14/42),小型企业工人的听力损失检出率较高(19.32%,296/1532);不同经济类型企业噪声作业工人疑似职业性噪声聋检出率差异有统计学意义(P<0.05),私营企业工人的疑似职业性噪声聋检出率较高(1.29%,36/2782)。结论株洲市噪声作业危害严重,应加强非金属矿采选行业和小型、私营企业的职业卫生防护措施,加大职业卫生执法力度,保护劳动者健康。 展开更多
关键词 噪声 职业性 听力损失 疑似职业性噪声聋 职业暴露
Noise Reduction for Digital Communications—The Masterpiece, a Modified Costas Loop 认领
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作者 János Ladvánszky 《电路与系统(英文)》 2020年第6期57-64,共8页
An efficient way of noise reduction has been presented: A modified Costas loop called as Masterpiece. The basic version of the Costas loop has been developed for SSB SC demodulation, but the same circuit can be applie... An efficient way of noise reduction has been presented: A modified Costas loop called as Masterpiece. The basic version of the Costas loop has been developed for SSB SC demodulation, but the same circuit can be applied for QAM (quadrature amplitude modulation) demodulation as well. Noise sensitivity of the basic version has been decreased. One trick is the transformation of the real channel input into complex signal, the other one is the application of our folding algorithm. The result is that the Masterpiece provides a 4QAM symbol error rate (SER) of 6 × 10<sup><span style="white-space:nowrap;">&#8722;</span>4</sup> for input signal to noise ratio (SNR) of <span style="white-space:nowrap;">&#8722;</span>1 dB. In this paper, an improved version of the original Masterpiece is introduced. The complex channel input signal is normalized, and rotational average is applied. The 4QAM result is SER of 3 × 10<sup><span style="white-space:nowrap;">&#8722;</span>4</sup> for SNR of <span style="white-space:nowrap;">&#8722;</span>1 dB. At SNR of 0 dB, the improved version produces 100 times better SER than that the original Costas loop does. In our times, this topic has a special importance because by application of our Masterpiece, all dangerous field strengths from 5G and WiFi, could be decreased by orders of magnitude. The Masterpiece can break the Shannon formula. 展开更多
关键词 Noise Symbol Error Rate QAM Costas Loop Hilbert Filter Folding Algorithm
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汽车空调的气动噪声分析与降噪方案设计 认领
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作者 李春花 徐鹏 赵玉垒 《制冷与空调》 2020年第3期45-49,共5页
利用数值仿真和试验相结合的方法,开展在研车型空调系统气动噪声的研究。运用宽频噪声源模型和计算气动声学方法(CAA),对某汽车空调系统的气动噪声进行数值模拟,得到空调内部的噪声源分布情况,仿真和试验的频谱变化趋势比较吻合,风量最... 利用数值仿真和试验相结合的方法,开展在研车型空调系统气动噪声的研究。运用宽频噪声源模型和计算气动声学方法(CAA),对某汽车空调系统的气动噪声进行数值模拟,得到空调内部的噪声源分布情况,仿真和试验的频谱变化趋势比较吻合,风量最大偏差为3.5%。给出优化风道型面、改变蜗舌形状、风道包裹吸声棉等降噪措施。 展开更多
关键词 汽车空调 噪声 仿真和试验 降噪
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炼化企业噪声对员工听力和心血管系统影响分析及对策研究 认领
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作者 赵盛 孙迪 +1 位作者 于金宁 张昌运 《安全.健康和环境》 2020年第6期43-46,共4页
采取整群抽样方法,分析炼化企业噪声暴露组和对照组相关指标差异性,探讨生产性噪声对作业人员听力和心血管系统的影响。针对随接触噪声工龄增加而出现的听力损伤、高血压和心电图等异常检出率上升的趋势,炼化企业应采取相应有效措施预... 采取整群抽样方法,分析炼化企业噪声暴露组和对照组相关指标差异性,探讨生产性噪声对作业人员听力和心血管系统的影响。针对随接触噪声工龄增加而出现的听力损伤、高血压和心电图等异常检出率上升的趋势,炼化企业应采取相应有效措施预防生产性噪声危害,积极推进健康企业示范建设,切实提高职业人群身心健康水平。 展开更多
关键词 炼化企业 噪声 听力损伤 心血管系统 噪声防护
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录音中降噪系统的使用 认领
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作者 周湘辉 《电声技术》 2020年第1期56-57,89共3页
由于各种原因,录音录制的音频会出现不可避免的噪声,当噪声影响音频效果时就需要降噪来处理。文章论述降噪系统在录音过程中的作用以及常用降噪系统的分析。
关键词 噪声 降噪系统 杜比
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基于几何声线法的噪声预测软件 认领
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作者 魏浩征 陈鑫 +1 位作者 张祖安 江涛 《环境保护科学》 CAS 2020年第1期119-122,共4页
在对项目工程进行噪声评价和治理时,运用噪声预测软件进行准确的噪声计算具有重大的实际意义。文章对一款自主研制的基于几何声线法的户外噪声预测软件的主要功能模块、设计和开发策略等相关问题进行了阐述。该软件能够建立图形化的声... 在对项目工程进行噪声评价和治理时,运用噪声预测软件进行准确的噪声计算具有重大的实际意义。文章对一款自主研制的基于几何声线法的户外噪声预测软件的主要功能模块、设计和开发策略等相关问题进行了阐述。该软件能够建立图形化的声学模型,自动计算多点的噪声级,并绘制噪声分布图。经比较,该软件与国外同类软件间的计算结果计算误差很小,其具备很好的应用价值。 展开更多
关键词 声学 噪声 噪声预测 应用价值
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特高压直流输电线路噪声生态污染控制算法研究 认领
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作者 黄振宁 《环境科学与管理》 CAS 2020年第9期81-85,共5页
输电线路噪声生态污染控制是特高压直流输电亟待解决的关键问题之一,为此,研究特高压直流输电线路噪声生态污染控制算法。采用BPA经验公式获取特高压直流输电线路导线表面最大电场,结合导线半径、导线分裂数和计算点与正极间距离,计算... 输电线路噪声生态污染控制是特高压直流输电亟待解决的关键问题之一,为此,研究特高压直流输电线路噪声生态污染控制算法。采用BPA经验公式获取特高压直流输电线路导线表面最大电场,结合导线半径、导线分裂数和计算点与正极间距离,计算特高压直流输电线路可听噪声,在此基础上,采用基于鸡群算法(CSO)优化阈值的提升小波变换去噪算法,获取小波分解系数,并搜寻最优阈值,然后提升小波逆变换得到重构噪声信号,完成特高压直流输电线路可听噪声生态污染控制。 展开更多
关键词 特高压 噪声 生态污染 控制 去噪
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