基于声生态学的城市景观设计策略探讨

声景观研究以其新奇和意想不到为城市景观研究设计带来新的切入点和手法。简要介绍了声生态学中声景的概念和发展;讨论和分析城市景观规划中引入声景观的必要性和可能性;探讨在景观生态学指导下的景观、声景观策略。     

香港海沙资源的勘探开发与管理

海沙开采已成为仅次于油气开采的世界第二重要海洋开采业。1980年代以来,香港政府投资1.7×10⁸港元为寻找海岸围垦填料进行了一系列的海沙勘探活动,在1828km²香港水域发现22个地点海沙资源储量7.4×10⁸m³,其中9个地点4.2×10⁸m³储量因覆盖层较厚或污染严重或海区环境特别敏感等原因被暂时搁置。1990～2002年共开采海沙2.7×10⁸m³,为形成2100hm²新土地的多项围垦工程提供了约一半的填料。基于地球物理勘探和钻探资料建立了香港海域第四纪层序和海沙产状地质模型,发现和证实了含气沉积物地震剖面的声波浑浊现象。香港政府对海沙资源进行统一勘探和统一管理,强调海沙开采的环境和生态影响评估,利用废弃的海床挖沙坑回填倾废的非污染海泥和受污染海泥。我国内地海沙勘探管理可以从中取得借鉴。     

Efficacy of extracting indices from large‐scale acoustic recordings to monitor biodiversity

Passive acoustic monitoring could be a powerful way to assess biodiversity across large spatial and temporal scales. However, extracting meaningful information from recordings can be prohibitively time consuming. Acoustic indices (i.e., a mathematical summary of acoustic energy) offer a relatively rapid method for processing acoustic data and are increasingly used to characterize biological communities. We examined the relationship between acoustic indices and the diversity and abundance of biological sounds in recordings. We reviewed the acoustic‐index literature and found that over 60 indices have been applied to a range of objectives with varying success. We used 36 of the most indicative indices to develop a predictive model of the diversity of animal sounds in recordings. Acoustic data were collected at 43 sites in temperate terrestrial and tropical marine habitats across the continental United States. For terrestrial recordings, random‐forest models with a suite of acoustic indices as covariates predicted Shannon diversity, richness, and total number of biological sounds with high accuracy (R² ≥ 0.94, mean squared error [MSE] ≤170.2). Among the indices assessed, roughness, acoustic activity, and acoustic richness contributed most to the predictive ability of models. Performance of index models was negatively affected by insect, weather, and anthropogenic sounds. For marine recordings, random‐forest models poorly predicted Shannon diversity, richness, and total number of biological sounds (R² ≤ 0.40, MSE ≥ 195). Our results suggest that using a combination of relevant acoustic indices in a flexible model can accurately predict the diversity of biological sounds in temperate terrestrial acoustic recordings. Thus, acoustic approaches could be an important contribution to biodiversity monitoring in some habitats.     

水力空化的最佳条件研究

采用了不同几何尺寸的孔板作为水力空化发生器,研究了流量、进口压力、孔内流速、孔板的孔径与厚度之比及孔板过流总面积与管道横截面积的比值对空化数的影响,得出进口压力控制在20mH2O,孔内流速控制在14.5m/s,δ/d为1.8s,为0.06,空化效果较好.     

调理剂对CAF污泥浓缩工艺影响的试验研究

涡凹气浮（CAF）已广泛应用于工业废水和城市污水的预处理中.由于污泥本身的特性原因,CAF在污泥处理中尚没有应用.通过试验投加污泥调理剂改变污泥的特性,以达到将CAF工艺用于浓缩活性污泥的目的.试验表明,CAF工艺浓缩低浓度剩余活性污泥效果很好,但正确选择污泥调理剂的投加点和投加量对CAF污泥浓缩工艺至关重要.     

高频超声辐照降解水中4-氯酚的研究

本文着重探讨了高频超声波 (1.7MHz)降解 4 氯酚的反应过程和反应机理 ,研究了高频超声波降解 4 氯酚的效果 ,并讨论了 4 氯酚初始浓度等因素对降解效果的影响。高频超声波降解 4 氯酚为一级反应 ,超声波空化效应在降解过程中起主导作用     

Noise system在道路工程声环境影响预测中的应用研究

采用Noise system模型软件预测城市道路工程对周围敏感目标的影响.通过预测,拟建道路沿线路中心线两侧200 m范围内随距离增大受交通噪声影响呈明显衰减趋势.从路段达标距离分析,相对于昼间噪声达标距离,夜间噪声达标距离均大于昼间的达标距离,说明拟建道路夜间交通噪声影响大于昼间;沿线敏感点近期、中期、远期昼间、夜间噪声预测值均能满足《声环境质量标准》(GB 3096-2008)中2类、4a类标准;通过对首排在建小区均为3层以上建筑物不同垂直高度的影响进行预测,对居民区不会造成影响.     

浅层小尺度隐伏断层地表勘探的正演模拟及应用

采用二维声波方程有限差分法对浅层小尺度隐伏断层地质模型的地震波场响应进行数值模拟,分别从震源位于断层下降盘顶、断层上升盘顶及断层顶三个不同位置进行正演模拟,对地震波场在断层模型中的传播规律及其地震记录变化特征进行了详细分析。结果表明多个单炮记录的变化对比不仅可以对断层进行快速有效的判断,而且为分析断层几何类型、估计断裂带范围与宽度等方面提供重要的依据。同时将模拟结果应用到实际生产中,取得了较好的应用效果。该方法能有效辅助实际野外工作中对断层的判断,为合理设计观测系统及采集参数设置提供指导,对提高浅层地震勘探现场工作效率和精度具有重要作用。     

点声源环境噪声声场区域二维图形化表征方法研究

针对环境噪声监测中单一点声源声场图形化表征机理,依据点声源衰减规律建立了点声源声场二维平面表征算法,据此以网格化区域范围内非均匀布置少量监测点方法确定声源点,再经克里金插值法反演点声源声场平面分布规律,最后通过ArcGIS软件平台实现噪声图形化展示.以5×5网格化区域为例,其非均匀布点数应不少于3个,最佳布点数为3组共计6个点,其实测值与理论值最大误差为4.3％.仿真试验验证表明,点声源图形表征符合实际声场分布规律.     

Influence of Environmental Factors on the Evolution of Industrial Noise-Induced Hearing Loss

The aim of the study is to investigate how environmental factors, associated with exposure to industrial noise, affect the development of chronic noise-induced hearing loss.The studywas conducted on 186 male subjectsworking in two bottling plants, situated respectively in a small farming community, and in a medium-sized city with significant levels of noise pollution. Levels of occupational exposure were the same for the two groups.The subjects were selected by means of a preliminary medical examination, and exposed to tonal hearing tests and acoustic impedance tests. Statistical analysis was performed on hearing threshold values obtained at the frequencies of 500, 1000, 2000 and 4000 Hz.The comparison between the thresholds obtained in the two groups showed a statistically significant difference, especially at the frequency of 4000 Hz and for occupational exposure exceeding 17 yr. The results led us to conclude that environmental factors, and urban noise in particular, influence the onset and development of occupational acoustic trauma, and that those working in the country are significantly less affected than those in the city. Since occupational exposure was the same for both groups, their different responses must therefore be interpreted as due to differences in nonoccupational exposure, in turn dependent on different opportunities for rest from noise and different levels of exposure to noise pollution.