声屏障参数简易计算方法的探讨

声屏障作为从传播途径解决噪声问题的一种有效措施,得到了越来越多的应用。本文简单介绍了声屏障设计的一般步骤和设置所需考虑的周边环境条件的一般原则;同时还介绍了一种简易声屏障参数计算方法,通过声屏障衰减理论和工程实践验证,证明了计算方法的可行性,为声屏障工程应用提供借鉴。     

试音室建筑声学缺陷查找及音质改造工程案例分析

对某试音室进行建筑声学测试、体验,对存在的颤动回声、低频共振等建筑声学缺陷及问题进行分析,在此基础上,根据试音室的功能使用需求,提出建筑声学音质改造方案,以此为例阐明了建筑声学缺陷的查找和修正方法。     

广东省绿色居住建筑隔声要求及现状

声环境是居住物理环境的重要组成部分。近年来城市居民对噪声问题的投诉始终高居不下,一方面源于城市环境声环境的持续恶化,另一方面则是与居住建筑隔声性能紧密相关。本文将在考察广东省近几年新建居住建筑围护结构的材料选择、构造做法基础上,评估其隔声性能。通过与建筑隔声的相关规定比对,分析这些居住建筑满足要求的情况,并对广东省绿色居住建筑的隔声设计提出建议。     

武汉工业大学水泵房噪声治理

分析了水泵房噪声产生的机理,提出以隔声为主,辅以消声、吸声、绿化等综合治理措施,实现了治理达标目的。     

Frog call intensities and sound propagation in the South American temperate forest region

Sound pressure levels and the spectral structure of the advertisement calls of five species of frogs from the South American temperate austral forest were analyzed. Males of Eupsophus emiliopugini, Batrachyla antartandica and B. leptopus call from the ground in bogs, while males of Hylorina sylvatica and Pleurodema thaul call from the water surface in marshes. Calling males of the species from bogs and marshes spaced at average distances that were shorter and longer than 2 m, respectively. The properties of these habitats for sound propagation were evaluated by broadcasting pure tones, broadband noise and tape-recorded advertisement calls of the three species from bogs and of H. sylvatica. Excess attenuation and spectral degradation were higher for calls broadcast in bogs than in the marsh. The calls of B.␣antartandica and B. leptopus, with dominant frequencies of about 2 kHz, were more affected than those of E.␣emiliopugini and H. sylvatica, with dominant frequencies below 1.5 kHz. These results show the lack of an optimal relationship between properties of habitats for sound transmission and the spectral structure of these anuran calls. Body size imposes an important constraint on call spectra and propagation, which frogs counteract by distribution patterns and auditory capabilities. Received: 18 April 1997 / Accepted after revision: 15 February 1998     

Stream corridor management in the Pacific Northwest: II. Management strategies

King County, Washington is part of the rapidly growing Pacific Northwest region. Analysis of past and current federal, state, and county regulations and administation reveals how stream corridors have been protected to date. This article draws on scientific literature and a case study to suggest future management strategies and guidelines for controlling development in King County watersheds.     

个人保护头盔的回声与隔声性能

设计中使用了自相关函数测试混响声衰变速度、自功率谱（参考传递函数与冲击响应）测试插入损失的方法，对头盔的回声与隔声效果进行客观分析。其结果表明，不同设计的头盔的回声与隔声性能，确实有很大差别。     

Net drift in an atypical estuary,Long Island Sound

Long Island Sound is an estuary with two-layered flow at the eastern opening to the ocean and a salinity gradient of about 5 parts per thousand between the eastern and western extremes. Tidal currents, wind-driven circulation, and river inflow and fresh water influx are investigated as factors affecting the net drift. Current measurements in eastern Long Island Sound indicate that the tidal circulation features that predominate there do not normally affect the net drift at the New Haven dump site. Drifter returns and a numerical model indicate that seasonal prevailing winds seem to be the primary cause of the net drift in central Long Island Sound.     

Vibrational signals in the tremble dance of the honeybee,Apis mellifera

Summary The tremble dance is a behavior sometimes performed by honeybee foragers returning to the hive. The biological significance of this behavior was unclear until Seeley (1992) demonstrated that tremble dances occur mainly when a colony's nectar influx is so high that the foragers must undertake lenghty searches in order to find food storers to unload their nectar. He suggested that tremble dancing has the effect of stimulating additional bees to function as food-storers, thereby raising the colony's capacity for processing nectar. Here I describe vibrational signals emitted by the tremble dancers. Simulation experiments with artificial tremble dance sounds revealed that these sounds inhibited dancing and reduced recruitment to feeding sites. The results suggest that the tremble dance is a negative feedback system counterbalancing the positive feedback of recruitment by waggle dances. Thus, the tremble dance seems to affect not only the colony's nectar processing rate, but also its nectar intake rate.     

A multidimensional decision-support approach to sustainable development planning

SUMMARY

The concept of sustainable development has become widely accepted as an instrumental objective of resource planning and environmental policy analysis. Nevertheless, applied planning approaches appropriate to this task have been slow in forthcoming. This paper suggests that one avenue for the application of sustainable development principles to resource management problems may be through multidimensional decision-support models. This approach recognizes that contemporary decision problems in the field of environmental planning are characterized by a diversity of structures and processes, incommensurable variables, and conflicting development objectives and constraints. On the basis of the articulated approach to sustainable development, a case study centred on Clayoquot Sound, British Columbia, Canada is presented. The case study serves to illustrate the efficacy of a multidimensional decision-support approach to sustainable development.