Given that the development of scour downstream of hydraulic structures increases the risk of structural damage,it is important to find cost-effective and environmental approaches to reduce this risk.This study aimed t...Given that the development of scour downstream of hydraulic structures increases the risk of structural damage,it is important to find cost-effective and environmental approaches to reduce this risk.This study aimed to experimentally evaluate the effect of synthetic fibers on the scour profile downstream of a sluice gate with a rigid apron.Experiments were performed with the same Froude number and with different weight percentages of synthetic fibers on both non-cohesive and cohesive sediments.One uniform sand was used as the non-cohesive sediment,and three different cohesive sediments were prepared by mixing different percentages of kaolinite soil with the used sand.The scouring experiments showed that the presence of synthetic fibers did not considerably affect the scour hole dimension in non-cohesive sediments.Evaluation of the scour in the cohesive sediments in silty sand(SM)texture found that an increase in the percentage of silt reduced the scour hole dimensions.The effect of synthetic fibers on scour of SM-texture-based sediments was also investigated,and the results showed that increasing the percentage of synthetic fibers decreased the scour hole dimensions.In addition,the cohesive sediments in SM texture did not have a similar non-dimensional scour profile,and the presence of synthetic fibers did not significantly affect the scour hole.展开更多
个人护理品(personal care products,PCPs)是属于药物及个人护理品(pharmaceuticals and personal care products,PPCPs)的一类新生污染物质。大量研究表明,该类物质对生态环境和人类健康会产生不利影响。对环境中PCPs残留进行生态风险...个人护理品(personal care products,PCPs)是属于药物及个人护理品(pharmaceuticals and personal care products,PPCPs)的一类新生污染物质。大量研究表明,该类物质对生态环境和人类健康会产生不利影响。对环境中PCPs残留进行生态风险评价已成为该领域的研究重点。我国PCPs的环境污染状况不容乐观,而其生态风险评价方面的研究显得极为薄弱。该文就环境中PCPs研究现状以及国外生态风险评价研究进展进行了综合分析和讨论,为建立适合我国PCPs污染特点的生态风险评价体系提供重要参考。展开更多
文摘Given that the development of scour downstream of hydraulic structures increases the risk of structural damage,it is important to find cost-effective and environmental approaches to reduce this risk.This study aimed to experimentally evaluate the effect of synthetic fibers on the scour profile downstream of a sluice gate with a rigid apron.Experiments were performed with the same Froude number and with different weight percentages of synthetic fibers on both non-cohesive and cohesive sediments.One uniform sand was used as the non-cohesive sediment,and three different cohesive sediments were prepared by mixing different percentages of kaolinite soil with the used sand.The scouring experiments showed that the presence of synthetic fibers did not considerably affect the scour hole dimension in non-cohesive sediments.Evaluation of the scour in the cohesive sediments in silty sand(SM)texture found that an increase in the percentage of silt reduced the scour hole dimensions.The effect of synthetic fibers on scour of SM-texture-based sediments was also investigated,and the results showed that increasing the percentage of synthetic fibers decreased the scour hole dimensions.In addition,the cohesive sediments in SM texture did not have a similar non-dimensional scour profile,and the presence of synthetic fibers did not significantly affect the scour hole.
文摘个人护理品(personal care products,PCPs)是属于药物及个人护理品(pharmaceuticals and personal care products,PPCPs)的一类新生污染物质。大量研究表明,该类物质对生态环境和人类健康会产生不利影响。对环境中PCPs残留进行生态风险评价已成为该领域的研究重点。我国PCPs的环境污染状况不容乐观,而其生态风险评价方面的研究显得极为薄弱。该文就环境中PCPs研究现状以及国外生态风险评价研究进展进行了综合分析和讨论,为建立适合我国PCPs污染特点的生态风险评价体系提供重要参考。