A Study of Annoyance Caused by Low-Frequency Noise During Mental Work

This article presents the results of an analysis of annoyance caused by low-frequency noise (including infrasonic noise) that occurs at work stations located in offices. The tests covered measurements of acoustic parameters specific for this type of noise and a survey conducted in the working environment and in laboratory conditions at a model of a work station.     

电力变压器无线温度监测系统的研究

我国变配电用变压器数量众多、分布广泛,充分利用现有的无线电通讯技术、以太网等监测技术、可以构建一个安全可靠的变压器无线温度监测网。本文介绍了在配电变压器上安装无线温度监测系统,通过实时监测变压器的温度变化情况,及时发现变压器存在的缺陷或发生故障的位置,并通过中短距离无线网络转发方式,将信号传递至以太网,彻底解决现场监测配电变压器参数的困难,从而实现变压器数据的实时采集和传输,实现区域内乃至全国性的变配电变压器信息的汇集与监测体系。     

A Digital Filter for the State Estimation of Impulsive Noise Under the Existence of a Background Noise and its Experiment in the Work Environment

In the actual work environment, a specific objective noise, like machine and industrial noises, shows impulsive fluctuation form. Furthermore, it often occurs that a specific noise is partially or completely contaminated by background noise. In that case, the fluctuation wave form of the specific noise has to be estimated moment by moment in order to evaluate and/or improve the work environment. In this study, a digital filter for estimating an impulsively fluctuating specific noise is proposed. More specifically, after introducing a generalized time series regressive model of the specific noise, a method for estimating the impulsive noise based on an observation contaminated by the background noise is theoretically derived. Furthermore, the proposed method is applied to the actual task of estimating an industrial impact noise.     

变压器火灾及预防

本文通过详细分析变压器火灾原因，提出预防变压器火灾的技术措施，供生产厂家、使用单位和消防监督管理部门有关技术人员、生产者、监管人员参考。     

Noise Control Strategies for Occupational Safety and Better Working Environments

Hearing impairment in humans due to occupational noise exposure is one of the significant occupational diseases in many countries. The equipment to measure noise levels and daily noise exposure in existing noisy environments is readily available and can be used to assess the risk of hearing damage. This article examines the currently legislated hearing damage risk criterion and compares the two main noise level-time trade-off schemes being used. The engineering methods for controlling excessive noise levels and techniques to either bring them below the hearing damage risk threshold or to within an acceptable range for the workplace requirement are discussed, together with the expected improvements by such measures.     

Analysis of noise pollution in an andesite quarry with the use of simulation studies and evaluation indices

This paper presents the verification of two partial indices proposed for the evaluation of continuous and impulse noise pollution in quarries. These indices, together with the sound power of machines index and the noise hazard index at the workstation, are components of the global index of assessment of noise hazard in the working environment of a quarry. This paper shows the results of acoustic tests carried out in an andesite quarry. Noise generated by machines and from performed blasting works was investigated. On the basis of acoustic measurements carried out in real conditions, the sound power levels of machines and the phenomenon of explosion were determined and, based on the results, three-dimensional models of acoustic noise propagation in the quarry were developed. To assess the degree of noise pollution in the area of the quarry, the continuous and impulse noise indices were used.     

Evaluation of noise environments during daily activities of university students

Noise conditions specifically in areas inside university facilities and its impact on the quality of life of university students are topics that have received little attention. This paper presents a study of the noise conditions in which university students of various institutions in Madrid, Spain, carry out their daily studies. A representative number of measurements was carried out using noise dosemeters and dataloggers in order to evaluate the levels of noise, noise dose and exposure to noise during school periods and extracurricular activities. The results were compared with the recommendations given by current environmental noise regulations. This paper was complemented with a survey to get to know how students perceive the exposure to noise in university environments.     

On Evaluation and Localization of Auditory Warning Devices for Adequate Audibility

This paper presents an analytic procedure to assist safety practitioners in evaluating the audibility of an existing auditory warning system in their workplaces. Two alarm location models are described: (a) a model with an unknown signal sound level, and (b) a model with a known signal sound level. A heuristic algorithm to determine a minimum number of alarm devices and their locations so that the warning signals can be clearly heard by workers is also proposed. The algorithm considers the ambient noise level, noise levels generated by individual machines, locations where workers are likely to be present, and noise levels at worker locations. From the numerical examples and the computation experiment, both the optimization and heuristic approaches yield solutions that satisfy the 15-dBA constraints. The heuristic approach is efficient in solving large alarm location problems due its capability to find near-optimal solutions within reasonable computation time.     

不同因素对特高压变压器励磁涌流的影响

为了研究特高压变压器产生的励磁涌流对特高压变压器差动保护的影响,运用MATLAB/SIMULINK,建立了特高压变压器仿真模型,参数按照晋东南—南阳—荆门1000kV特高压交流试验示范工程中的相关数据设置。利用所建立的模型进行空载投切的仿真,分析了合闸角与剩磁对励磁涌流的影响。仿真结果验证了控制合理的合闸角与剩磁可以限制励磁涌流的出现,从而避免特高压变压器差动保护误动,为提出新的识别励磁涌流判据提供了理论基础。     

Determining Attenuation of Impulse Noise With an Electrical Equivalent of a Hearing Protection Device

Determining the effectiveness of impulse noise attenuation with hearing protection devices (HPDs) is an important part of their selection. Measuring impulse noise parameters under an HPD would involve exposing subjects to impulses with a high peak sound pressure level. This paper presents a computational method of determining impulse noise parameters under the cups of earmuffs. Calculations are done using the transfer function of earmuffs, determined with Shaw’s electrical equivalent of an HPD, taking into account the design parameters of earmuffs. The developed method was used for calculations in the presence of impulse noise generated by gunshots. To verify the computational method, the results of these calculations were compared with the results of measurements.     

Application of Neural Networks in Active Noise Reduction Systems

Active noise reduction systems based on a control unit in the form of a finite impulse response filter assume the linearity of every single component. Neural networks, which have so far been seldom used in this field, are a kind of a filter with the ability to project nonlinear characteristics of an active noise reduction system. This paper presents some simulation research studies of active noise reduction systems based on neural networks. Also presented are results of the operation of systems with different levels of complexity as well as the influence of different parameters of a neural network and of the system itself on those results.     

基于FXLMS算法的矿用有源耳罩的研究

基于矿井中低频噪声突出,存在时间长、危害大,尤其周期性噪声比重较大,而传统降噪技术对其降噪效果并不明显,提出了基于fxlms 算法的自适应有源降噪耳罩降低矿井中的低频周期性信号,并采用离线建模方法建立了次级通道模型,利用MATLAB8.0拟合了64阶的滤波器,对 矿井中具有代表性的1kHz低频周期噪声和伴有随机噪声的1kHz低频周期性噪声进行了降噪仿真研究。结果表明:1kHz低频周期性噪声的降噪量 达到了30dB。而且在本模型下,随机噪声对低频周期性噪声的降噪效果几乎没有影响。     

八十年代工业噪声控制的几个主要进展——我国工业噪声控制技术水平评述

回顾并阐述了80年代国内外在工业噪声控制方面的几个主要进展。通过对比,分析评述我国当前工业噪声控制技术的实际水平。虽然我国在噪声控制技术的某些方面,例如计算机在工业噪声预测和控制方面的应用、声强测量、有源消声的实际应用等方面,同国外相比尚有一定差距,但就总体来说,我国的噪声控制技术水平同世界先进国家相比,大体相当,有的方面甚至还要超过。为达到有效控制我国工业噪声危害的目的,建议除进一步加强噪声控制技术的研究外,制定并推行有效的听力保护计划是至关重要的。     

井下有限空间内作业人员噪声危害调查

为研究煤矿井下环境相对封闭、空间相对有限的情况下,噪声对作业人员的影响及危害,通过问卷调查的形式,分别对开滦集团东欢坨及荆各庄2煤矿井下5个不同作业区人员进行了共计200份的噪声危害问卷调查。将问卷调查结果通过SPSS软件进行统计与分析,并将SPSS分析得到的数据用于分析井下噪声对作业人员的影响及危害,归纳出噪声对作业人员的影响因素,并对噪声、影响因素及症状之间建立了井下噪声对作业人员影响的理论关系模型。结果表明:在井下有限空间内,噪声对作业人员的危害最严重的症状是耳鸣,危害最轻的症状是畏惧感;参与调查的多为年龄较大、工龄较长的作业人员,噪声对工龄较长者的危害程度要大于对年龄较大者,且工龄与噪声危害之间存在Pearson相关性系数大于0的正相关关系。     

典型直升机噪声特点及其防护需求分析

直升机工作时,旋翼、尾桨及发动机传动系统可产生90dB （A）以上的噪声。本文从听感知角度分析了典型直升机噪声的声压级、特征频率及能量分布等特点及其防护需求。     

柴油发电机房的噪声控制技术

柴油发电机组是一种广泛使用的备用供电设备,机组引发的环境噪声污染问题日益得到重视.对某电信局紧急备用的柴油发电机组进行噪声频谱特性分析和周围环境状况的分析,针对性地提出吸声、隔声、消声、减振以及通风散热的治理措施.经过治理后,达到了环境噪声Ⅱ类区域排放标准的要求,同时也满足了柴油发电机组工作时的通风散热要求.     

健康住宅的降噪问题与技术措施

健康住宅的噪声控制,包括对噪声源的认识、进行降噪的方法设计、技术措施实施效果的分析等内容。笔者在研究健康住宅噪声种类和控制标准、分析控制噪声基本措施的基础上,认为健康住宅噪声控制的难点在于设计方法和技术措施两方面,解决问题的思路是将降噪手段视为系统工程,包括住区户外和住宅室内两大系统;综合设计降噪控制技术,才能达到健康住宅声环境的控制标准。     

城市轨道交通站台噪声测量研究

为研究城市轨道交通高架和地下站台噪声的规律和特点,选取某条线路中的3个高架站台以及3条线路中的7个地下站台进行实地测量,并对测量结果进行分析。研究结果表明:地下站台LAeq值都低于标准限值80 dB(A);站台的中心测点列车进站LAeq值和列车出站LAeq值都非常接近,使用T检验结果得出各站台中心测点列车进站LAeq值和列车出站LAeq值不存在显著差异（P>0.05）;站台测量时要考虑大客流带来的喧闹声;站台最大噪声值是列车出站时,位于站台列车车头停止位置。     

上海市浦东新区2014-2018年声环境质量状况分析

上海市浦东新区作为承接国家自由贸易区的先行试点地区,近年来吸引大批国内外企业入驻,同时经济发展与环境友好型社会矛盾依然突出。本文以2014年-2018年来浦东新区区域噪音与交通噪数据为依据,分析本地区声环境状况,结果表明声环境质量有所下降,一类功能区及交通噪音需进一步加强治理。通过源头屏蔽,大力发展张江、周浦、滴水湖等科技园区建设,阻断企业对居民区的噪声影响等措施,进而提升和改善浦东新区声环境质量状况。