公路交通噪声对人影响的研究

本文采用客观测量和主观评价相结合的方法研究公路交通噪声对人的影响。通过研究，求得了公路交通噪声扰民的容忍阈值，分析比较了公路交通噪声各种客观评价量与人的主观评价量之间的相互关系，研究结果表明，公路交通噪声扰民充分体现在其高声级对人的影响、评价公路交通噪声采用统计声级L10比等效声级Leq更贴合于人的主观感觉。     

嘉兴市交通噪声污染的分析与防治建议

通过监测嘉兴市主要交通干道的噪声值、车流量等,用等效声级（L eq）、累积百分声级、噪声污染级（L NP）、噪声污染指数（P N）和交通噪声指数（TNI）进行噪声污染综合评价和分析,并针对当前嘉兴市交通发展现状,分析噪声污染原因及影响因素,并提出有效控制噪声的相关建议。     

道路交通噪声中单车辐射噪声测量及分析

以道路通行的单个车辆为研究对象,导出半自由场单车点声源的噪声辐射模型,应用噪声测量分析手段,结合相应的声学评价量,对实际道路条件下单车辐射噪声的声级大小、时域信号、频谱、声学品质等特性进行探讨和研究。结果表明,随车辆与测点距离的变化,单车辐射声的声级呈现先增大后减小的非线性变化规律;其高频声压级随距离增加而衰减;与小车相比,中车和重车辐射噪声中的低频成份比例大,声级值高;小车辐射声响度在低频125Hz和高频1kHz频段的贡献量较大,重车则体现为低频段（250~500 Hz）贡献量大,而高频段的贡献量不明显。     

中型客车车内加速噪声特性的实验研究

车内加速噪声是车辆NVH特性的重要方面之一.分析了中型客车急加速和慢加速车内噪声A声级随发动机转速的变化规律,在对其进行时频域分析的基础上,归纳出了两种加速噪声在噪声特性方面的不同.两种加速噪声的频率结构基本相同,但急加速噪声频率成分比慢加速噪声略高.某一转速下的急加速噪声A声级比对应转速下的慢加速噪声大2～3 dB.     

噪声暴露声级在广佛高速公路交通噪声评价和预测中的应用

一、引言 目前,国内外的交通噪声通常采用等效声级L_(eq)作为基本评价量,按照常规的取样方法得到的结果实际上包括了交通噪声和其它噪声,并没有完全反映出交通噪声的实际情况。另外,在交通噪声的评价和预测方面,目前仍停留在依靠大量实测数据的回归分析方法的应用上,而且回归方程又逐年有所变化,对于今后的长期预测缺乏置信度。     

《往复压缩机噪声测试分析》

利用声级计和双通道数据采集器对现场往复压缩机进行噪声测试和分析研究进行了声级测试和频谱测试。按照工业企业厂界噪声标准对噪声A声级进行了评价。通过频谱分析,找到了噪声源的主要特征以及主要噪声源。最后提出了噪声治理措施。     

环境噪声对人体心脏负荷影响规律的研究

本文应用《研究环境噪声对心脏影响规律的方法与实现》中提出的研究与实现方法,通过标准人机工程实验获得以倍频程为划分根据的宽频域不同声级噪声对人体负荷的影响规律。结果表明：不同噪声因素的影响具有不同的变化规律性,噪声频率影响最显著,其次是不同的噪声阶段的影响,而噪声级的影响不显著。这些规律可为降低工业噪声对人体负荷的影响提供依据。     

高速化列车的轮轨噪声研究

列车速度是影响轮轨噪声大小的主要因素之一，由于轮轨噪声对车速的信赖性，其声级将随着列车不断高速化会愈来愈大，目前已有许多文献对轮机轨噪声进行研究并提出一些措施，然而对于轮轨噪声，由车轮振动产生的辐射噪声是主要的，还是由钢轨辐射是主要的等，还有一些不明的地方，目前提出的降噪措施很多，然而采取何种措施对降低轮轨噪声更有利，更具有“实用性”和“经济性”也不十分清楚，本文通过轮轨噪声的理论分析和实验数据分     

空调系统中的低频噪声

低频噪音污染问题受到了人们越来越多的关注。本文对通风、空调系统中的低频噪声及其产生做了详细的介绍；讨论了低频噪声的评价问题，提出用C声级来计量低频噪声的声级；从主观影响和客观影响两方面介绍了低频噪声对人的影响；介绍了有源噪声控制法在通风、空调系统中的应用。     

飞机噪声影响区域敏感建筑物隔声窗设计理念

以北京市首都国际机场飞机噪声为例,对飞机噪声影响区域内敏感建筑物隔声窗的设计进行研究。以1小时等效A声级LAeq作为飞机噪声影响区域内隔声窗设计时飞机噪声的评价量,并依据人对不同类型、不同时间段内噪声烦恼度的不同对LAeq值进行修正。根据修正后的LAeq值设计的隔声窗隔声量基本达到飞机噪声的防护要求。     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Assessment of intakes of mixtures of radionuclides

Australia has several uranium mines and a large number of mineral sand mines, with associated processing facilities. Exposures resulting from these mining and processing operations usually involve intakes of mixtures of radionuclides. This work describes the development of a suite of first order, linear compartment models, based on the ICRP Publication 66 respiratory tract model, and an analytical solution to the decay equations, for assessing the consequences of such intakes. The computer programs based on these models directly compute excretion, organ retention and organ and whole-body doses for intakes of either single radionuclides or any mixture of radionuclides belonging to the same radioactive decay chain. The intake can be via inhalation, ingestion or injection, and can be acute, chronic or of limited duration. The starting concentration and degree of secular (dis)equilibrium can be specified for each radionuclide. No assumptions need to be made about the relative magnitudes of the radioactive half-lives of the different nuclides.     

卧式金属罐容量的测量结果不确定度

本文根据多年的实践检定经验 ,参照JJF1 0 59- 1 999《测量不确定度评定与表示》以及《测量不确定度表达 1 0讲》 ,对卧式金属罐容量的测量结果不确定度进行了评定。     

盐酸浓度不确定度的评估

通过对盐酸浓度标定的过程分析，找出影响结果的各个分量，进行不确定度的评定，按照计量技术规范给出标准的表示法。     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue.     

Analysis of the rate of propagation of the wave of change of boiling modes

An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.     

Analysis of anisotropy of properties on the basis of studies of texture of coarse-grained ingots of thermoelectric materials

An analysis of anisotropy of the properties of a Bi₂Se_0.3Te_2.7 solid solution was carried out using construction of demonstrative surfaces for thermoelectric effectiveness and thermal expansion coefficients. It is shown that the texture is an important factor forming anisotropy of properties and technological fitness of ingots for manufacturing modules. Anisotropy of properties based on the studies of the ingot textures obtained using the float-zone method and Bridgman method (growing thermoelectric plates in a flat cavity) was studied.