摘要：影响噪声烦恼的声学参量较多,然而在传统噪声控制工程中,往往仅根据A计权声压级所需降低量进行控制方案设计,未能从烦恼改善程度优选方案.为此,本研究提出一种基于烦恼改善程度优选噪声控制方案的方法,并将该方法应用于变电站声屏障噪声控制方案的比选.结果表明,同一声屏障方案对不同关心点噪声烦恼的改善程度差异较大,A计权声压级降低量最大的声屏障方案对噪声烦恼的改善效果未必最好.因此,噪声控制工程设计中,宜根据所关心的声环境保护目标与噪声源的相对位置,选取对保护目标处噪声烦恼改善程度较大的方案.

摘要：A long-term drought has led to the mass mortality of shrubs in the semi-arid Israeli *** most impacted shrub species is the Noaea mucronata(Forssk.)*** *** a four-year study,we found that herbaceous vegetation growth was greater in the dead shrub patches than in the surrounding inter-patch biocrusted spaces,suggesting that the dead shrub patches encompass improved ***,unexpectedly,the soil moisture in the dead shrub patches was consistently lower than that of the inter-patch biocrusted *** the same time,soil quality in the dead shrub patches was higher than that in the inter-patch ***,it seems that the overall better soil conditions in the dead patches overcome the scarcity of soil-water,supporting increased herbaceous *** explaining the discrepancy between herbaceous vegetation and soil-water,we formulated a conceptual framework,which highlights the key factors that regulate soil-water dynamics in this dryland *** demonstrate that herbaceous vegetation is facilitated in the dead shrub patches by a legacy effect that takes place long after the shrubs have *** dead shrub patches encompass a unique form of ecosystem *** study highlights the complex and unpredicted impacts of prolonged droughts on dryland ecosystems.