公路项目环评中低时速单车噪声源强研究

由于缺乏低时速单车噪声源强估算模式,低等级公路项目噪声预测结果常与实际监测结果存在较大偏差。文中通过实测各车型车辆在低时速条件下时速和单车辐射声级(Lmax)数据,运用统计软件分析两者间的关系,并通过实测过往车辆数据进行验证。结果显示沿用《公路建设项目环境影响评价规范》(以下简称《06规范》)中的公式计算低车速源强可能会造成结果偏低,建议采用下列式子估算低车速单车噪声源强:小型车L=21.5 lgV+34.96(15≤V≤63),中型车L=10.4 lgV+59.29(15≤V≤53),大型车15≤V≤48(15≤V≤48)。     

齐齐哈尔市建华区餐饮业噪声污染特点及防治对策

近年来城区餐饮业发展迅速,引发了一系列的环境问题。阐述了餐饮业噪声污染现状,产生污染的原因,并就如何解决这些问题提出了意见。     

Effects of Road Networks on Bird Populations

Abstract: One potential contributor to the worldwide decline of bird populations is the increasing prevalence of roads, which have several negative effects on birds and other vertebrates. We synthesized the results of studies and reviews that explore the effects of roads on birds with an emphasis on paved roads. The well‐known direct effects of roads on birds include habitat loss and fragmentation, vehicle‐caused mortality, pollution, and poisoning. Nevertheless, indirect effects may exert a greater influence on bird populations. These effects include noise, artificial light, barriers to movement, and edges associated with roads. Moreover, indirect and direct effects may act synergistically to cause decreases in population density and species richness. Of the many effects of roads, it appears that road mortality and traffic noise may have the most substantial effects on birds relative to other effects and taxonomic groups. Potential measures for mitigating the detrimental effects of roads include noise‐reduction strategies and changes to roadway lighting and vegetation and traffic flow. Road networks and traffic volumes are projected to increase in many countries around the world. Increasing habitat loss and fragmentation and predicted species distribution shifts due to climate change are likely to compound the overall effects of roads on birds.     

A NEW LOOK AT FLOOD RISK DETERMINATION1

ABSTRACT: The probability distributions of annual peak flows used in flood risk analysis quantify the risk that a design flood will be exceeded. But the parameters of these distributions are themselves to a degree uncertain and this uncertainty increases the risk that the flood protection provided will in fact prove to be inadequate. The increase in flood risk due to parameter uncertainty is small when a fairly long record of data is available and the annual flood peaks are serially independent, which is the standard assumption in flood frequency analysis. But standard tests for serial independence are insensitive to the type of grouping of high and low values in a time series, which is measured by the Hurst coefficient. This grouping increases the parameter uncertainty considerably. A study of 49 annual peak flow series for Canadian rivers shows that many have a high Hurst coefficient. The corresponding increase in flood risk due to parameter uncertainty is shown to be substantial even for rivers with a long record, and therefore should not be neglected. The paper presents a method of rationally combining parameter uncertainty due to serial correlation, and the stochastic variability of peak flows in a single risk assessment. In addition, a relatively simple time series model that is capable of reproducing the observed serial correlation of flood peaks is presented.     

剥壳机系统噪声控制技术

剥壳机生产系统将胡豆打碎和去壳时发出严重的扰民噪声,对产生噪声的设备和管道采用隔声和吸声控制措施。结果表明,效果十分明显,达到了国家环境噪声排放标准。     

控制排气放空噪声的消声器之研究与应用

排气放空噪声是工业上常遇到的噪声源。本文介绍了根据喷注噪声发射理论研制成的小孔喷注与节流降压相复合的新型消声器，适用于高压气源排放，取得了较好的消声效果。鉴于喷注发射噪声的强度取决于喷注的驻压与喷口直径等参量，对节流降压层的设计与控制小孔喷注层的驻压大小，提出了新的见解，可供设计研究喷注消声器参考使用。     

干燥过程中的噪声危害及防治措施

粮食烘干过程的噪声危害必须引起人们的重视，通过对噪声产生的根源及给作业人员健康带来的损害进行分析，结合生产实际，提出了防治措施。     

卧具烘干房蒸汽噪声的治理

针对卧具烘干房蒸汽噪声严重的情况，利用小孔喷射消声原理，采用喷射小孔扩散式蒸汽消声器，并结合工程实际对消声器作了适当改进，治理效果均达到《城市区域环境噪声标准》ＧＢ９０９６—８２二类混合区标准。     

Predicting mass rapid transit noise levels on an elevated station

This study developed a noise prediction model for elevated mass rapid transit (MRT) platforms. Relevant physical and operational parameters (e.g. cruise speed, acceleration and deceleration rates for trains, building fa?ade setbacks and so on) were collected from the Bangkok mass transit system (BTS), the first elevated MRT system operated in Bangkok, Thailand. The equivalent continuous sound pressure levels (L(Aeq)) were collected from both sides of the MRT stations at the center of each platform. The relevant parameters were collected on both platforms and ground level, on both sides of MRT stations. These parameters were statistically tested to determine their correlation with MRT noise. The final model was built from highly correlated parameters using multiple regression analysis with a stepwise regression technique. Statistical evaluation showed a high degree of goodness-of-fit test for the model to the observed data. Therefore, it can be efficiently used for the projection of MRT noise in the affected areas.     

博乐市城市环境噪声分析及防治对策探讨

论述了博乐市自1992-2006年城市环境噪声状况,对交通噪声、生活噪声、建筑施工噪声及发展趋势进行了分析,并提出必须从城市总体规划的战略高度统筹实施综合整治,有效地控制噪声污染.