【目的】文章为探究再生水补水对城市水生态和水环境的具体影响,保障再生水安全、高效的利用,为再生水回用于城市河湖的研究提供参考。【方法】基于再生水在城市河湖生态补水领域的应用实践与研究成果,通过中国知网和Web of Science数据...【目的】文章为探究再生水补水对城市水生态和水环境的具体影响,保障再生水安全、高效的利用,为再生水回用于城市河湖的研究提供参考。【方法】基于再生水在城市河湖生态补水领域的应用实践与研究成果,通过中国知网和Web of Science数据库,检索与“再生水”“再生水生态补水”“reclaimed water”“reclaimed water recharge”相关的4万余篇文献,从年度发文量、研究焦点、发展趋势与前沿等角度进行研究分析。【结果】再生水补水将影响其流速和流量等关键参数,其中可能含有营养盐、重金属及新型污染物等成分,会改变受纳河湖水质,影响水生生物的生长速率和群落结构。相关文献统计,受纳水体在增加补水频率、增设补水点或加倍补水量等措施实施后,整体水质有所改善。【结论】再生水补给河湖能够改善水质,但其对生态环境健康的考虑相对不足,且各项水质标准规范的约束性指标数量和阈值存在差异,这进一步增加了潜在的生态环境风险,并且补水影响因素的设置与调控会影响再生水的补水效果。同时,未来研究应聚焦探索再生水补水改善河湖水环境的机制,提升污水处理技术,完善评价体系及构建智慧管理平台,以管控补水风险、保障生态环境安全和优化补水模式,推进城市河湖生态的健康、和谐与可持续发展。展开更多
Sizing treatment is a suitable technique to modify the fiber-matrix interfaces without damage of inherent performance of fibers.In this work,sizing agents based on Janus particles(JPs)were utilized to enhance the inte...Sizing treatment is a suitable technique to modify the fiber-matrix interfaces without damage of inherent performance of fibers.In this work,sizing agents based on Janus particles(JPs)were utilized to enhance the interface of basalt fiber(BF)/poly(vinyl chloride)(PVC)composites.polystyrene/poly(butyl acrylate)(PS/PBA)@silica JPs were synthesized by seed emulsion polymerization and three different sizing agents were prepared for BF sizing treatment.JPs with organic soft sphere and inorganic hard hemisphere enhanced the interfaces through their amphiphilicity,chemical bonding and mechanical interlock.The mechanical properties of composite with JPs sizing treated BFs performed better when there was one JPs layer modified on the interface.According to the intermitting bonding and gradient modulus theory,JPs patterned interfaces are ideal transition layers between high modulus BF and low modulus PVC.展开更多
The geostress and rock blasting in underground engineering may greatly affect the stress thresholds of surrounding rock.In this study,pre-damage impact tests were first conducted on granite under varying confining pre...The geostress and rock blasting in underground engineering may greatly affect the stress thresholds of surrounding rock.In this study,pre-damage impact tests were first conducted on granite under varying confining pressures(5,10 and 15 MPa)and numbers of impacts(1,5,10 and 15 impacts).Then,uniaxial compression tests were undertaken on the pre-damaged granite to study the evolution of stress thresholds using the crack volume strain method and acoustic emission method.The crack damage stresses determined by the two methods were compared.Additionally,based on the rise time amplitude and average frequency,the evolution law of microcracks inside rock specimens was revealed,and an improved acoustic emission method was proposed.The results indicated that as the number of impacts increased,the crack closure stress,crack damage stress,and peak stress of granite specimens initially rose and then declined,while they continuously increased with the confining pressure.The proportion of shear cracks first declined and then rose with greater number of impacts and decreased with higher confining pressure,and that of tensile cracks showed the opposite trend.The improved acoustic emission method was more accurate in identifying the crack damage stress.展开更多
文摘【目的】文章为探究再生水补水对城市水生态和水环境的具体影响,保障再生水安全、高效的利用,为再生水回用于城市河湖的研究提供参考。【方法】基于再生水在城市河湖生态补水领域的应用实践与研究成果,通过中国知网和Web of Science数据库,检索与“再生水”“再生水生态补水”“reclaimed water”“reclaimed water recharge”相关的4万余篇文献,从年度发文量、研究焦点、发展趋势与前沿等角度进行研究分析。【结果】再生水补水将影响其流速和流量等关键参数,其中可能含有营养盐、重金属及新型污染物等成分,会改变受纳河湖水质,影响水生生物的生长速率和群落结构。相关文献统计,受纳水体在增加补水频率、增设补水点或加倍补水量等措施实施后,整体水质有所改善。【结论】再生水补给河湖能够改善水质,但其对生态环境健康的考虑相对不足,且各项水质标准规范的约束性指标数量和阈值存在差异,这进一步增加了潜在的生态环境风险,并且补水影响因素的设置与调控会影响再生水的补水效果。同时,未来研究应聚焦探索再生水补水改善河湖水环境的机制,提升污水处理技术,完善评价体系及构建智慧管理平台,以管控补水风险、保障生态环境安全和优化补水模式,推进城市河湖生态的健康、和谐与可持续发展。
基金supported by the National Natural Science Foundation of China(Nos.U22A20252 and 52173076)the Beijing Natural Science Foundation(Nos.Z240030 and L248023)the Liaoning Province Key Research and Development Project(No.2024JH2/102400046)。
文摘Sizing treatment is a suitable technique to modify the fiber-matrix interfaces without damage of inherent performance of fibers.In this work,sizing agents based on Janus particles(JPs)were utilized to enhance the interface of basalt fiber(BF)/poly(vinyl chloride)(PVC)composites.polystyrene/poly(butyl acrylate)(PS/PBA)@silica JPs were synthesized by seed emulsion polymerization and three different sizing agents were prepared for BF sizing treatment.JPs with organic soft sphere and inorganic hard hemisphere enhanced the interfaces through their amphiphilicity,chemical bonding and mechanical interlock.The mechanical properties of composite with JPs sizing treated BFs performed better when there was one JPs layer modified on the interface.According to the intermitting bonding and gradient modulus theory,JPs patterned interfaces are ideal transition layers between high modulus BF and low modulus PVC.
基金Project(2023YFC2907400)by the National Key Research and Development Program of China-2023 Key Special ProjectProject(51974043)supported by the National Natural Science Foundation of China+2 种基金Project(SKLCRKF1908)supported by the Open Fund of the State Key Laboratory of Coal Resources in Western China,Xi’an University of Science and Technology,ChinaProject(2023JJ10072)suupported by the Hunan Provincial Natural Science Foundation for Distinguished Young ScholarsProject(2022RC1173)supported by the Science and Technology Innovation Program of Hunan Province,China。
文摘The geostress and rock blasting in underground engineering may greatly affect the stress thresholds of surrounding rock.In this study,pre-damage impact tests were first conducted on granite under varying confining pressures(5,10 and 15 MPa)and numbers of impacts(1,5,10 and 15 impacts).Then,uniaxial compression tests were undertaken on the pre-damaged granite to study the evolution of stress thresholds using the crack volume strain method and acoustic emission method.The crack damage stresses determined by the two methods were compared.Additionally,based on the rise time amplitude and average frequency,the evolution law of microcracks inside rock specimens was revealed,and an improved acoustic emission method was proposed.The results indicated that as the number of impacts increased,the crack closure stress,crack damage stress,and peak stress of granite specimens initially rose and then declined,while they continuously increased with the confining pressure.The proportion of shear cracks first declined and then rose with greater number of impacts and decreased with higher confining pressure,and that of tensile cracks showed the opposite trend.The improved acoustic emission method was more accurate in identifying the crack damage stress.
