Radiative cooling technologies can passively gain lower temperature than that of ambient surroundings without consuming electricity,which has emerged as potential alternatives to traditional cooling methods.However,th...Radiative cooling technologies can passively gain lower temperature than that of ambient surroundings without consuming electricity,which has emerged as potential alternatives to traditional cooling methods.However,the limitations in daytime radiation intensity with a net cooling power of less than 150 W·m^(−2) have hindered progress toward commercial practicality.Here,we report an integrated radiative and evaporative chiller(IREC)based on polyacrylamide hydrogels combined with an upper layer of breathable poly(vinylidene fluoride-co-trifluoroethylene)fibers,which achieves a record high practical average daytime cooling power of 710 W·m^(−2).The breathable fiber layer has an average emissivity of over 76%in the atmospheric window,while reflecting 90%of visible light.This IREC possesses effective daytime radiative cooling while simultaneously ensuring evaporative cooling capability,enhancing daytime passive cooling effectively.As a result,IREC presents the practicability for both personal cooling managements and industrial auxiliary cooling applications.An IREC-based patch can assist in cooling human body by 13℃ low for a long term and biocompatible use,and IREC can maintain the temperature of industrial storage facilities such as oil tanks at room temperature even under strong sunlight irradiation.This work delivers the highest performance daytime passive cooling by simultaneous infrared radiation and water evaporation,and provides a new perspective for developing highly efficient,scalable,and affordable passive cooling strategy.展开更多
Urban drainage pipe network is the backbone of urban drainage,flood control and water pollution prevention,and is also an essential symbol to measure the level of urban modernization.A large number of underground drai...Urban drainage pipe network is the backbone of urban drainage,flood control and water pollution prevention,and is also an essential symbol to measure the level of urban modernization.A large number of underground drainage pipe networks in aged urban areas have been laid for a long time and have reached or practically reached the service age.The repair of drainage pipe networks has attracted extensive attention from all walks of life.Since the Ministry of ecological environment and the national development and Reform Commission jointly issued the action plan for the Yangtze River Protection and restoration in 2019,various provinces in the Yangtze River Basin,such as Anhui,Jiangxi and Hunan,have extensively carried out PPp projects for urban pipeline restoration,in order to improve the quality and efficiency of sewage treatment.Based on the management practice of urban pipe network restoration project in Wuhu City,Anhui Province,this paper analyzes the problems of lengthy construction period and repeated operation caused by the mismatch between the design schedule of the restoration scheme and the construction schedule of the pipe network restoration in the existing project management mode,and proposes a model of urban drainage pipe network restoration scheme selection based on the improved support vector machine.The validity and feasibility of the model are analyzed and verified by collecting the data in the project practice.The research results show that the model has a favorable effect on the selection of urban drainage pipeline restoration schemes,and its accuracy can reach 90%.The research results can provide method guidance and technical support for the rapid decision-making of urban drainage pipeline restoration projects.展开更多
基金This work was supported by the financial support from National Natural Science Foundation of China(Nos.52073159,22035005,52022051,22075165,and 52090030)State Key Laboratory of Tribology(No.SKLT2021B03)+1 种基金Tsinghua-Foshan Innovation Special Fund(No.2018THFS0412)This work is also supported by a grant(No.2019GQG1025)from the Institute for Guo Qiang,Tsinghua University.
文摘Radiative cooling technologies can passively gain lower temperature than that of ambient surroundings without consuming electricity,which has emerged as potential alternatives to traditional cooling methods.However,the limitations in daytime radiation intensity with a net cooling power of less than 150 W·m^(−2) have hindered progress toward commercial practicality.Here,we report an integrated radiative and evaporative chiller(IREC)based on polyacrylamide hydrogels combined with an upper layer of breathable poly(vinylidene fluoride-co-trifluoroethylene)fibers,which achieves a record high practical average daytime cooling power of 710 W·m^(−2).The breathable fiber layer has an average emissivity of over 76%in the atmospheric window,while reflecting 90%of visible light.This IREC possesses effective daytime radiative cooling while simultaneously ensuring evaporative cooling capability,enhancing daytime passive cooling effectively.As a result,IREC presents the practicability for both personal cooling managements and industrial auxiliary cooling applications.An IREC-based patch can assist in cooling human body by 13℃ low for a long term and biocompatible use,and IREC can maintain the temperature of industrial storage facilities such as oil tanks at room temperature even under strong sunlight irradiation.This work delivers the highest performance daytime passive cooling by simultaneous infrared radiation and water evaporation,and provides a new perspective for developing highly efficient,scalable,and affordable passive cooling strategy.
基金supported by the Funds for the Anhui Provincial Science and Technology Innovation Strategy and Soft Science Research Project(Grant Number 202206f01050017)National Natural Science Foundation of China(Grant Number 72131006,6201101347,72071063)+3 种基金Fundamental Research Funds for the Central Universities(Grant Number JS2021ZSPY0037)Research Project of China Three Gorges Corporation(Grant Number 202103355)Yangtze Ecology and Environment Co.,Ltd.(Grant Number HB/AH2021039)Power China Huadong Engineering Corporation Limited(KY2019-ZD-03).
文摘Urban drainage pipe network is the backbone of urban drainage,flood control and water pollution prevention,and is also an essential symbol to measure the level of urban modernization.A large number of underground drainage pipe networks in aged urban areas have been laid for a long time and have reached or practically reached the service age.The repair of drainage pipe networks has attracted extensive attention from all walks of life.Since the Ministry of ecological environment and the national development and Reform Commission jointly issued the action plan for the Yangtze River Protection and restoration in 2019,various provinces in the Yangtze River Basin,such as Anhui,Jiangxi and Hunan,have extensively carried out PPp projects for urban pipeline restoration,in order to improve the quality and efficiency of sewage treatment.Based on the management practice of urban pipe network restoration project in Wuhu City,Anhui Province,this paper analyzes the problems of lengthy construction period and repeated operation caused by the mismatch between the design schedule of the restoration scheme and the construction schedule of the pipe network restoration in the existing project management mode,and proposes a model of urban drainage pipe network restoration scheme selection based on the improved support vector machine.The validity and feasibility of the model are analyzed and verified by collecting the data in the project practice.The research results show that the model has a favorable effect on the selection of urban drainage pipeline restoration schemes,and its accuracy can reach 90%.The research results can provide method guidance and technical support for the rapid decision-making of urban drainage pipeline restoration projects.
