Solar-powered interfacial evaporation is an energy-efficient solution for water scarcity.It requires solar absorbers to facilitate upward water transport and limit the heat to the surface for efficient evaporation.Fur...Solar-powered interfacial evaporation is an energy-efficient solution for water scarcity.It requires solar absorbers to facilitate upward water transport and limit the heat to the surface for efficient evaporation.Furthermore,downward salt ion transport is also desired to prevent salt accumulation.However,achieving simultaneously fast water uptake,downward salt transport,and heat localization is challenging due to highly coupled water,mass,and thermal transport.Here,we develop a structurally graded aerogel inspired by tree transport systems to collectively optimize water,salt,and thermal transport.The arched aerogel features root-like,fan-shaped microchannels for rapid water uptake and downward salt diffusion,and horizontally aligned pores near the surface for heat localization through maximizing solar absorption and minimizing conductive heat loss.These structural characteristics gave rise to consistent evaporation rates of 2.09 kg m^(-2) h^(-1) under one-sun illumination in a 3.5 wt%NaCl solution for 7 days without degradation.Even in a high-salinity solution of 20 wt%NaCl,the evaporation rates maintained stable at 1.94 kg m^(-2) h^(-1) for 8 h without salt crystal formation.This work offers a novel microstructural design to address the complex interplay of water,salt,and thermal transport.展开更多
Electrically conductive porous structures are ideal candidates for lightweight and absorption-dominant electromagnetic interference(EMI)shielding.In this review,we summarize the recent progress in developing porous co...Electrically conductive porous structures are ideal candidates for lightweight and absorption-dominant electromagnetic interference(EMI)shielding.In this review,we summarize the recent progress in developing porous composites and structures from emerging two-dimensional(2D)graphene and MXene nanosheets for EMI shielding applications.Important properties contributing to various energy loss mechanisms are probed with a critical discussion on their correlations with EMI shielding performance.Technological approaches to constructing bulk porous structures,such as 2D porous films,three-dimensional(3D)aerogels and foams,and hydrogels,are compared to highlight important material and processing parameters required to achieve optimal microstructures.A comprehensive comparison of EMI shielding performance is also carried out to elucidate the effects of different assembly techniques and microstructures.Distinctive multifunctional applications in adaptive EMI shielding,mechanical force attenuation,thermal management,and wearable devices are introduced,underlining the importance of unique compositions and microstructures of porous composites.The process–structure–property relationships established in this review would offer valuable guidance and insights into the design of lightweight EMI shielding materials.展开更多
Phantom limb is a disabling neuropsychiatric condition among amputees resulting in pain and disturbance that impact their functions,quality of life,and autonomy.While pharmacological approaches appeared to be ineffec-...Phantom limb is a disabling neuropsychiatric condition among amputees resulting in pain and disturbance that impact their functions,quality of life,and autonomy.While pharmacological approaches appeared to be ineffec-tive,the emergence and integration of X-reality,including virtual reality,augmented reality,and mixed reality,might elevate the effectiveness of mirror therapy in managing phantom limb.The objective of this study is to review X-reality for managing phantom pain.A systematic search was conducted on PubMed,Scopus,Web of Science,PsycINFO,Embase,and CINAHL.Sixteen(n=16)studies containing 66 lower-limb and 53 upper-limb amputees were included for the review over the thematic framework of amputee characteristics and intervention designs,while thirteen(n=13)studies were further proceeded for the meta-analysis.We found eleven studies on virtual reality(n=11),four studies on marker-based augmented reality(n=4)and one study on mixed reality(n=1)with a total of 40 game/task themes involving,motor skills,motor control,and stimulus-sensing.Regardless,all these interventions adopted the movement representation strategies with different techniques.Overall,the X-reality interventions reduced the pain level of the amputees(mean difference:-2.30,95%CI,-3.38 to-1.22),especially the virtual reality subgroup(mean difference:-2.83,95%CI,-4.43 to-1.22).However,there were substantial heterogeneity and partially explained by the subgroup analysis on publication year.The strength of evidence was limited by case reports and case series in this review.展开更多
The increasing need for electromagnetic interference(EMI)shielding of electronics in cold environments such as those in aircraft,space exploration,and wearable heaters to avoid hazardous icing conditions or hypothermi...The increasing need for electromagnetic interference(EMI)shielding of electronics in cold environments such as those in aircraft,space exploration,and wearable heaters to avoid hazardous icing conditions or hypothermia requires the development of thin and lightweight EMI shielding materials preferably by absorbing rather than reflecting electromagnetic(EM)waves while also generating heat through energy-efficient electrothermal conversion.However,it is challenging to achieve absorption-dominant EMI shielding and energy-efficient electrothermal heating simultaneously in a thin and lightweight structure.Here,we develop a heterogeneous composite film comprising a porous multi-walled carbon nanotubes(MWCNTs)/bacterial cellulose(BC)film and an aligned MXene/Ag nanowires(NWs)backing via a sequential vacuum filtration process.The porous film contains random conductive networks of MWCNTs with moderate conductivity while the aligned MXene sheets atop Ag NWs network affords high conductivity in the backing,giving rise to graded electrical conductivity for absorption-dominant EMI shielding.The increasing Ag NW coverage leads to significantly increased electrical conductivity without increasing the EM wave reflection as well as the density and thickness of the film,yielding excellent specific EMI shielding effectiveness(>8500 dB/(g·cm^(2))),low driving voltage for energy-efficient electrothermal heating(163℃at 2.5 V),and fast response time(60 s)at a low areal density of 0.015 mg/cm^(2).Combining EMI shielding and electrothermal heating,the heterogeneous film developed here are promising contenders for the protection of electronic equipment in low-temperature environment.展开更多
During pregnancy,women experience substantial changes in physiology,morphology,and hormonal systems.These changes have profound effects on the biomechanics of the human body,particularly the musculoskeletal system,res...During pregnancy,women experience substantial changes in physiology,morphology,and hormonal systems.These changes have profound effects on the biomechanics of the human body,particularly the musculoskeletal system,resulting in discomfort,pain,and decreased body stability.Sufficient biomechanical knowledge is critical for understanding the etiology and precautions of musculoskeletal disorders.With awareness of health problems in the pregnant cohort,identification,intervention,and precaution of problems have garnered attention.Researchers have conducted studies to determine the biomechanics of pregnancy.There have been review studies on summarization.However,to the best of our knowledge,few studies have comprehensively described biomechanical changes throughout pre-,in-,and postpartum periods.This review analyzed available studies on biomechanical changes during these three periods in the electronic databases of PubMed,Scopus,and Cochrane from inception until June 2,2021.Synthesized the general information,age of the studied subjects,investigated periods,sample size,objectives,measurement tools,and outcomes of reviewed studies.And Using National Institutes of Health quality assessment tool for observational cohort and cross-sectional studies to assessment the quality of the reviewed articles.These studies revealed biomechanical deviations in body stability,motion patterns,and gait modes during these three periods.Regarding research content,there are insufficient studies on certain critical biomechanical aspects,such as the kinetic parameters of the inner body,which are the most direct factors related to musculoskeletal problems.According to the National Institutes of Health quality assessment tool for observational cohort and cross-sectional studies,a more comprehensive and explicit understanding of pregnancy biomechanics can be expected.展开更多
Competitive diving is a popular sport that attracts numerous participants worldwide;unfortunately,competitive divers experience a notable frequency of injuries during training and competition.Despite this,injuries in ...Competitive diving is a popular sport that attracts numerous participants worldwide;unfortunately,competitive divers experience a notable frequency of injuries during training and competition.Despite this,injuries in diving often received less attention compared to those in other aquatic sports.The purpose of this study was to conduct a systematic review to update the scientific evidence on injury incidence in competitive divers to offer insights into the prevalent injury patterns and help develop injury prevention strategies.This involved analyzing injury data collected from the Injury Surveillance Programme(ISP)across various levels of competition events and assessing case reports involving a wide spectrum of diving injuries.Four online bibliographical databases were consulted:Google Scholar,PubMed,Scops,and Web of Science from their inception until December 6,2023.819 studies were initially identified,and 15 studies were finally included in this review.Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISM)guidelines and PRISMA in Exercise,Rehabilitation,Sport Medicine,and Sport Science(PERSiST)were followed.Two independent reviewers evaluated the methodological quality of the studies.The majority of diving injuries are concentrated on the upper body/trunk,including the shoulder,spine,hand/wrist,head/face,and neck,with overuse injury being a main contribution.Regarding diving incidence,the actual injury rate in competitive athletes could be even higher than currently reported,primarily due to limitations in implementing injury surveillance protocol for diving athletes.The latest injury data for diving in big competition events is absent,and there is a strong expectation for more new injury surveillance data to be published in the future.Additionally,the specific injury pattern,prevention strategy,and rehabilitation training plan for diving injury are severely deficient in the current literature.展开更多
Regenerative fuel cells can operate alternately as an electrolyzer and as a fuel cell,frequently involving water as a reactant or product.Modifying the electrode surface to manipulate water can prevent electrode flood...Regenerative fuel cells can operate alternately as an electrolyzer and as a fuel cell,frequently involving water as a reactant or product.Modifying the electrode surface to manipulate water can prevent electrode flooding and enhance the electrode's mass transfer efficiency by facilitating better contact with gaseous reactants.However,conventional electrodes face difficulties in allowing water droplets to penetrate in a single direction leaving electrodes.In this work to address this issue,a wettability gradient electrode is designed and fabricated for efficient water manipulation in regenerative fuel cells.The findings demonstrate that the water removal strategy in the electrolyzer mode yields the highest ammonia yield and Faradaic efficiency of 3.39×10-10 mol s-1 cm-2 and 0.49%,respectively.Furthermore,in the fuel cell mode,the discharging process sustains for approximately 20.5 h,which is six times longer than the conventional strategy.The ability to sustain the discharging process for extended periods is particularly advantageous in regenerative fuel cells,as it enables the cells to operate for longer periods without the need for regeneration.展开更多
Serious bubble clogging in flow-field channels will hinder the water supply to the electrode of proton exchange membrane water electrolyzer(PEMWE),deteriorating the cell performance.In order to address this issue,the ...Serious bubble clogging in flow-field channels will hinder the water supply to the electrode of proton exchange membrane water electrolyzer(PEMWE),deteriorating the cell performance.In order to address this issue,the dual-layer flow field design has been proposed in our previous study.In this study,the VOF(volume of fluid)method is utilized to investigate the effects of different degassing layer and base heights on the bubble behavior in channel and determine the time for the bubbles to detach from the electrode surface.However,it is very timeconsuming to get the optimal combination of base layer and degassing layer heights due to the large number of potential cases,which needs to be calculated through computation-intensive physical model.Therefore,machine learning methods are adopted to accelerate the optimization.A data-driven surrogate model based on deep neural network(DNN)is developed and successfully trained using data obtained by the physical VOF method.Based on the highly efficient surrogate,genetic algorithm(GA)is further utilized to determine the optimal heights of base layer and degassing layer.Finally,the reliability of the optimization was validated by bubble visualization in channel and electrochemical characterization in PEMWE through experiments.展开更多
基金financially supported by the Research Grants Council of Hong Kong SAR(16200720)Environment and Conservation Fund of Hong Kong SAR(Project No.21/2022)+2 种基金Young Scientists Fund of National Natural Science Foundation of China(Grant No.52303106)Research Institute for Advanced Manufucturing(Project No.CD8R)the startup fund for new recruits of PolyU(Project Nos.P0038855 and P0038858)。
文摘Solar-powered interfacial evaporation is an energy-efficient solution for water scarcity.It requires solar absorbers to facilitate upward water transport and limit the heat to the surface for efficient evaporation.Furthermore,downward salt ion transport is also desired to prevent salt accumulation.However,achieving simultaneously fast water uptake,downward salt transport,and heat localization is challenging due to highly coupled water,mass,and thermal transport.Here,we develop a structurally graded aerogel inspired by tree transport systems to collectively optimize water,salt,and thermal transport.The arched aerogel features root-like,fan-shaped microchannels for rapid water uptake and downward salt diffusion,and horizontally aligned pores near the surface for heat localization through maximizing solar absorption and minimizing conductive heat loss.These structural characteristics gave rise to consistent evaporation rates of 2.09 kg m^(-2) h^(-1) under one-sun illumination in a 3.5 wt%NaCl solution for 7 days without degradation.Even in a high-salinity solution of 20 wt%NaCl,the evaporation rates maintained stable at 1.94 kg m^(-2) h^(-1) for 8 h without salt crystal formation.This work offers a novel microstructural design to address the complex interplay of water,salt,and thermal transport.
基金This project was financially supported by the Research Grants Council(GRF Projects:16205517,16209917,and 16200720)the Innovation and Technology Commission(ITS/012/19)of Hong Kong SAR,and start-up fund for new recruits of PolyU(Nos.P0038855 and P0038858)This project was also supported by the Research Institute for Sports Science and Technology of PolyU(No.P0043535).
文摘Electrically conductive porous structures are ideal candidates for lightweight and absorption-dominant electromagnetic interference(EMI)shielding.In this review,we summarize the recent progress in developing porous composites and structures from emerging two-dimensional(2D)graphene and MXene nanosheets for EMI shielding applications.Important properties contributing to various energy loss mechanisms are probed with a critical discussion on their correlations with EMI shielding performance.Technological approaches to constructing bulk porous structures,such as 2D porous films,three-dimensional(3D)aerogels and foams,and hydrogels,are compared to highlight important material and processing parameters required to achieve optimal microstructures.A comprehensive comparison of EMI shielding performance is also carried out to elucidate the effects of different assembly techniques and microstructures.Distinctive multifunctional applications in adaptive EMI shielding,mechanical force attenuation,thermal management,and wearable devices are introduced,underlining the importance of unique compositions and microstructures of porous composites.The process–structure–property relationships established in this review would offer valuable guidance and insights into the design of lightweight EMI shielding materials.
基金The work was supported by the Research Institute for Sports Science and Technology(Reference number:P0043798)Internal Fund(Ref-erence number:P0035805)of the Hong Kong Polytechnic University.
文摘Phantom limb is a disabling neuropsychiatric condition among amputees resulting in pain and disturbance that impact their functions,quality of life,and autonomy.While pharmacological approaches appeared to be ineffec-tive,the emergence and integration of X-reality,including virtual reality,augmented reality,and mixed reality,might elevate the effectiveness of mirror therapy in managing phantom limb.The objective of this study is to review X-reality for managing phantom pain.A systematic search was conducted on PubMed,Scopus,Web of Science,PsycINFO,Embase,and CINAHL.Sixteen(n=16)studies containing 66 lower-limb and 53 upper-limb amputees were included for the review over the thematic framework of amputee characteristics and intervention designs,while thirteen(n=13)studies were further proceeded for the meta-analysis.We found eleven studies on virtual reality(n=11),four studies on marker-based augmented reality(n=4)and one study on mixed reality(n=1)with a total of 40 game/task themes involving,motor skills,motor control,and stimulus-sensing.Regardless,all these interventions adopted the movement representation strategies with different techniques.Overall,the X-reality interventions reduced the pain level of the amputees(mean difference:-2.30,95%CI,-3.38 to-1.22),especially the virtual reality subgroup(mean difference:-2.83,95%CI,-4.43 to-1.22).However,there were substantial heterogeneity and partially explained by the subgroup analysis on publication year.The strength of evidence was limited by case reports and case series in this review.
基金supported by the Young Scientists Fund of National Natural Science Foundation of China(No.52303106)Research Grants Council of Hong Kong SAR(No.16200720)+3 种基金Environment and Conservation Fund of Hong Kong SAR(No.21/2022)Research Institute of Sports Science and Technology(No.P0043535)Research Institute of Advanced Manufacturing(No.P0046125)the start-up fund for new recruits of PolyU(Nos.P0038855 and P0038858).
文摘The increasing need for electromagnetic interference(EMI)shielding of electronics in cold environments such as those in aircraft,space exploration,and wearable heaters to avoid hazardous icing conditions or hypothermia requires the development of thin and lightweight EMI shielding materials preferably by absorbing rather than reflecting electromagnetic(EM)waves while also generating heat through energy-efficient electrothermal conversion.However,it is challenging to achieve absorption-dominant EMI shielding and energy-efficient electrothermal heating simultaneously in a thin and lightweight structure.Here,we develop a heterogeneous composite film comprising a porous multi-walled carbon nanotubes(MWCNTs)/bacterial cellulose(BC)film and an aligned MXene/Ag nanowires(NWs)backing via a sequential vacuum filtration process.The porous film contains random conductive networks of MWCNTs with moderate conductivity while the aligned MXene sheets atop Ag NWs network affords high conductivity in the backing,giving rise to graded electrical conductivity for absorption-dominant EMI shielding.The increasing Ag NW coverage leads to significantly increased electrical conductivity without increasing the EM wave reflection as well as the density and thickness of the film,yielding excellent specific EMI shielding effectiveness(>8500 dB/(g·cm^(2))),low driving voltage for energy-efficient electrothermal heating(163℃at 2.5 V),and fast response time(60 s)at a low areal density of 0.015 mg/cm^(2).Combining EMI shielding and electrothermal heating,the heterogeneous film developed here are promising contenders for the protection of electronic equipment in low-temperature environment.
基金This research was funded by the National Natural Science Foundation of China(No.11972315).
文摘During pregnancy,women experience substantial changes in physiology,morphology,and hormonal systems.These changes have profound effects on the biomechanics of the human body,particularly the musculoskeletal system,resulting in discomfort,pain,and decreased body stability.Sufficient biomechanical knowledge is critical for understanding the etiology and precautions of musculoskeletal disorders.With awareness of health problems in the pregnant cohort,identification,intervention,and precaution of problems have garnered attention.Researchers have conducted studies to determine the biomechanics of pregnancy.There have been review studies on summarization.However,to the best of our knowledge,few studies have comprehensively described biomechanical changes throughout pre-,in-,and postpartum periods.This review analyzed available studies on biomechanical changes during these three periods in the electronic databases of PubMed,Scopus,and Cochrane from inception until June 2,2021.Synthesized the general information,age of the studied subjects,investigated periods,sample size,objectives,measurement tools,and outcomes of reviewed studies.And Using National Institutes of Health quality assessment tool for observational cohort and cross-sectional studies to assessment the quality of the reviewed articles.These studies revealed biomechanical deviations in body stability,motion patterns,and gait modes during these three periods.Regarding research content,there are insufficient studies on certain critical biomechanical aspects,such as the kinetic parameters of the inner body,which are the most direct factors related to musculoskeletal problems.According to the National Institutes of Health quality assessment tool for observational cohort and cross-sectional studies,a more comprehensive and explicit understanding of pregnancy biomechanics can be expected.
文摘Competitive diving is a popular sport that attracts numerous participants worldwide;unfortunately,competitive divers experience a notable frequency of injuries during training and competition.Despite this,injuries in diving often received less attention compared to those in other aquatic sports.The purpose of this study was to conduct a systematic review to update the scientific evidence on injury incidence in competitive divers to offer insights into the prevalent injury patterns and help develop injury prevention strategies.This involved analyzing injury data collected from the Injury Surveillance Programme(ISP)across various levels of competition events and assessing case reports involving a wide spectrum of diving injuries.Four online bibliographical databases were consulted:Google Scholar,PubMed,Scops,and Web of Science from their inception until December 6,2023.819 studies were initially identified,and 15 studies were finally included in this review.Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISM)guidelines and PRISMA in Exercise,Rehabilitation,Sport Medicine,and Sport Science(PERSiST)were followed.Two independent reviewers evaluated the methodological quality of the studies.The majority of diving injuries are concentrated on the upper body/trunk,including the shoulder,spine,hand/wrist,head/face,and neck,with overuse injury being a main contribution.Regarding diving incidence,the actual injury rate in competitive athletes could be even higher than currently reported,primarily due to limitations in implementing injury surveillance protocol for diving athletes.The latest injury data for diving in big competition events is absent,and there is a strong expectation for more new injury surveillance data to be published in the future.Additionally,the specific injury pattern,prevention strategy,and rehabilitation training plan for diving injury are severely deficient in the current literature.
基金supported by a grant from the National Natural Science Foundation of China(52161160333)a grant from the Research Grants Council of the Hong Kong Special Administrative Region,China(N_PolyU559/21)a grant from the Research Institute for Sports Science and Technology at The Hong Kong Polytechnic University(CD5L).
文摘Regenerative fuel cells can operate alternately as an electrolyzer and as a fuel cell,frequently involving water as a reactant or product.Modifying the electrode surface to manipulate water can prevent electrode flooding and enhance the electrode's mass transfer efficiency by facilitating better contact with gaseous reactants.However,conventional electrodes face difficulties in allowing water droplets to penetrate in a single direction leaving electrodes.In this work to address this issue,a wettability gradient electrode is designed and fabricated for efficient water manipulation in regenerative fuel cells.The findings demonstrate that the water removal strategy in the electrolyzer mode yields the highest ammonia yield and Faradaic efficiency of 3.39×10-10 mol s-1 cm-2 and 0.49%,respectively.Furthermore,in the fuel cell mode,the discharging process sustains for approximately 20.5 h,which is six times longer than the conventional strategy.The ability to sustain the discharging process for extended periods is particularly advantageous in regenerative fuel cells,as it enables the cells to operate for longer periods without the need for regeneration.
基金supported by a grant from National Natural Science Foundation of China(No.42302271)a grant from the Research Grants Council of the Hong Kong Special Administrative Region,China(No.N_PolyU559/21).
文摘Serious bubble clogging in flow-field channels will hinder the water supply to the electrode of proton exchange membrane water electrolyzer(PEMWE),deteriorating the cell performance.In order to address this issue,the dual-layer flow field design has been proposed in our previous study.In this study,the VOF(volume of fluid)method is utilized to investigate the effects of different degassing layer and base heights on the bubble behavior in channel and determine the time for the bubbles to detach from the electrode surface.However,it is very timeconsuming to get the optimal combination of base layer and degassing layer heights due to the large number of potential cases,which needs to be calculated through computation-intensive physical model.Therefore,machine learning methods are adopted to accelerate the optimization.A data-driven surrogate model based on deep neural network(DNN)is developed and successfully trained using data obtained by the physical VOF method.Based on the highly efficient surrogate,genetic algorithm(GA)is further utilized to determine the optimal heights of base layer and degassing layer.Finally,the reliability of the optimization was validated by bubble visualization in channel and electrochemical characterization in PEMWE through experiments.
