随着电子仪器与精密设备不断微型化、集成化,结构内部微振动严重影响其性能与寿命。颗粒阻尼结合激光粉末床熔融(laser powder bed fusion,LPBF)技术为抑制微振动提供了可能,但相关研究仍属空白,亟待探索。为探究基于LPBF成形的阻尼构...随着电子仪器与精密设备不断微型化、集成化,结构内部微振动严重影响其性能与寿命。颗粒阻尼结合激光粉末床熔融(laser powder bed fusion,LPBF)技术为抑制微振动提供了可能,但相关研究仍属空白,亟待探索。为探究基于LPBF成形的阻尼构件在微振动条件下的减振性能,该研究设计并一体化制备了具有不同隔板数量的隔板-自封粉阻尼梁,并采用动态热机械分析仪对其阻尼性能进行了表征。结果表明,随着隔板数量的增加,该结构的损耗因子逐渐提高,其变化趋势与粉末-内壁接触面积密切相关。相较于只有空腔的自封粉梁,设置11个隔板的梁在一定条件下损耗因子具有48%的提升,其微振动减振性能显著优于空腔梁及实体梁。该研究为基于LPBF工艺的自封粉结构在微振动条件下的阻尼性能调控与优化提供了有益参考。展开更多
Algal blooms in eutrophic water often produce microcystins,which can lead to multi-organ dysfunction and even mortality in many organisms.Therefore,the elimination of microcystins in water is an urgent issue that need...Algal blooms in eutrophic water often produce microcystins,which can lead to multi-organ dysfunction and even mortality in many organisms.Therefore,the elimination of microcystins in water is an urgent issue that needs to be addressed.Herein,we develop a dual defect engineering strategy to construct graphite-like carbon nitride with N vacancies and-C≡N groups(NgCN)nanosheets for microcystin-LR(MC-LR)photodegradation.According to our theoretical calculations and actual findings,the NgCN nanosheets enhanced recyclability for the removal of MC-LR while also demonstrating outstanding photocatalytic efficacy,significantly surpassing the graphite-like carbon nitride under visible light,which is ascribed to efficient charge separation as well as narrowing the bandgap.Impressively,the water quality after photodegradation has been proven to be safe based on International Organization for Standardization(ISO)standards.This finding provides meaningful insights into understanding the relationship between defect engineering and photodegradation performance to design photocatalytic materials with higher activity for environmental remediation.展开更多
文摘随着电子仪器与精密设备不断微型化、集成化,结构内部微振动严重影响其性能与寿命。颗粒阻尼结合激光粉末床熔融(laser powder bed fusion,LPBF)技术为抑制微振动提供了可能,但相关研究仍属空白,亟待探索。为探究基于LPBF成形的阻尼构件在微振动条件下的减振性能,该研究设计并一体化制备了具有不同隔板数量的隔板-自封粉阻尼梁,并采用动态热机械分析仪对其阻尼性能进行了表征。结果表明,随着隔板数量的增加,该结构的损耗因子逐渐提高,其变化趋势与粉末-内壁接触面积密切相关。相较于只有空腔的自封粉梁,设置11个隔板的梁在一定条件下损耗因子具有48%的提升,其微振动减振性能显著优于空腔梁及实体梁。该研究为基于LPBF工艺的自封粉结构在微振动条件下的阻尼性能调控与优化提供了有益参考。
基金supported by the National Natural Science Foundation of China(Nos.51778618 and 52070192)the National Water Pollution Control and Treatment Science and Technology Major Project(No.2017ZX07102).
文摘Algal blooms in eutrophic water often produce microcystins,which can lead to multi-organ dysfunction and even mortality in many organisms.Therefore,the elimination of microcystins in water is an urgent issue that needs to be addressed.Herein,we develop a dual defect engineering strategy to construct graphite-like carbon nitride with N vacancies and-C≡N groups(NgCN)nanosheets for microcystin-LR(MC-LR)photodegradation.According to our theoretical calculations and actual findings,the NgCN nanosheets enhanced recyclability for the removal of MC-LR while also demonstrating outstanding photocatalytic efficacy,significantly surpassing the graphite-like carbon nitride under visible light,which is ascribed to efficient charge separation as well as narrowing the bandgap.Impressively,the water quality after photodegradation has been proven to be safe based on International Organization for Standardization(ISO)standards.This finding provides meaningful insights into understanding the relationship between defect engineering and photodegradation performance to design photocatalytic materials with higher activity for environmental remediation.
