With the rapid advancement of portable energy devices and sensor technologies,enhancing their catalytic performance,sensing capabilities,and application reliability has become a critical challenge in the fields of mat...With the rapid advancement of portable energy devices and sensor technologies,enhancing their catalytic performance,sensing capabilities,and application reliability has become a critical challenge in the fields of materials and energy science.Single-atom catalysts(SACs),owing to their high atomic utilization,outstanding catalytic activity,and precisely engineered structures enabled by density functional theory and enhanced by artificial intelligence,have shown tremendous potential in advancing portable energy and sensing technologies.While existing reviews predominantly focus on the application of SACs in individual portable devices,systematic discussions on their overall development prospects and challenges within portable energy and sensor fields remain scarce.Therefore,this review comprehensively explores the application potential and recent advancements of SACs in portable zinc-air batteries,proton exchange membrane fuel cells,and sensor technologies.The article highlights the influence of key factors such as material design,structural optimization,and packaging integration on device performance,while also addressing the primary bottlenecks and challenges encountered in current practical applications.Furthermore,it suggests possible future development directions,aiming to offer theoretical insights and engineering guidance for the large-scale deployment of SACs in wearable electronic devices,portable energy systems,and smart sensing technologies.展开更多
The wearable sensors have recently attracted considerable attentions as communication interfaces through the information perception,decoding,and conveying process.However,it is still challenging to obtain a sensor tha...The wearable sensors have recently attracted considerable attentions as communication interfaces through the information perception,decoding,and conveying process.However,it is still challenging to obtain a sensor that can convert detectable signals into multiple outputs for convenient,e cient,cryptic,and high-capacity information transmission.Herein,we present a capacitive sensor of magnetic field based on a tilted flexible micromagnet array(t-FMA)as the proposed interaction interface.With the bidirectional bending capability of t-FMA actuated by magnetic torque,the sensor can recognize both the magnitude and orientation of magnetic field in real time with non-overlapping capacitance signals.The optimized sensor exhibits the high sensitivity of over 1.3 T-1 and detection limit down to 1 mT with excellent durability.As a proof of concept,the sensor has been successfully demonstrated for convenient,e cient,and programmable interaction systems,e.g.,touchless Morse code and Braille communication.The distinguishable recognition of the magnetic field orientation and magnitude further enables the sensor unit as a high-capacity transmitter for cryptic information interaction(e.g.,encoded ID recognition)and multi-control instruction outputting.We believe that the proposed magnetic field sensor can open up a potential avenue for future applications including information communication,virtual reality device,and interactive robotics.展开更多
Multi-temporal synthetic aperture radar interferometry(MT-InSAR)is a standard technique for mapping clustering and wide-scale deformation.A linear model is often used in phase unwrapping to overcome the underdetermina...Multi-temporal synthetic aperture radar interferometry(MT-InSAR)is a standard technique for mapping clustering and wide-scale deformation.A linear model is often used in phase unwrapping to overcome the underdetermination.It’s difficult to identify different types of nonlinear deformation.However,the interpretation of nonlinear deformation is very important in monitoring potential risk.This paper introduces a comprehensive approach for identifying and interpreting different types of deformation within InSAR datasets,integrating initial clustering and classification simplification.Initial classification is performed using the K-means clustering method to cluster the collected InSAR deformation time-series data.Then we use F test and Anderson-Darling test(AD test)to simplify the clusters after initial classification.This technique distinctly discerns the changing trends of deformation signals,thereby providing robust support for interpreting potential deformation scenarios within observed InSAR regions.展开更多
Synthetic aperture radar(SAR)is able to acquire high-resolution method using the active microwave imaging method.SAR images are widely used in target recognition,classification,and surface analysis,with extracted feat...Synthetic aperture radar(SAR)is able to acquire high-resolution method using the active microwave imaging method.SAR images are widely used in target recognition,classification,and surface analysis,with extracted features.Attribute scattering center(ASC)is able to describe the image features for these tasks.However,sidelobe effects reduce the accuracy and reliability of the estimated ASC model parameters.This paper incorporates the SAR super-resolution into the ASC extraction to improve its performance.Both filter bank and subspace methods are demonstrated for preprocessing to supress the sidelobe.Based on the preprocessed data,a reinforcement based ASC method is used to get the parameters.The experimental results show that the super-resolution method can reduce noise and suppress sidelobe effect,which improve accuracy of the estimated ASC model parameters.展开更多
Flexible sensors in wearable electronics have become increasingly multifunctional due to the development of materials synthesis and structure design.In particular,structural design can not only add capabilities to sen...Flexible sensors in wearable electronics have become increasingly multifunctional due to the development of materials synthesis and structure design.In particular,structural design can not only add capabilities to sensors fabricated from existing available and normal materials,but also offer opportunities for the fabrication of sensors with certain desired functions.Here,we designed a series of fiber-junction structure models,in which two fibers were simply hooked to each other to form a junction on a flexible printed circuit,for fabrication of directional bending sensors.The value and direction of bending angle are related to the change in electronic signal by a theoretical expression,allowing us to employ a simple and practicable method to use available conductive fiber materials to fabricate high-sensitivity,high-resolution and directional bending sensors.In addition,these models are generally applicable,which have broad combination with different conductive fiber,and corresponding bending sensors all possess capability of directional identification.Furthermore,the capability of identifying directional bending was demonstrated by human motion monitoring such as joint bending and muscle contraction.展开更多
Unmanned aerial vehicle(UAV)array InSAR is a new type of single-flight 3D SAR imaging system with the advantages of high coherence and resolution.However,due to the low altitude of the platform,the elevation ambiguity...Unmanned aerial vehicle(UAV)array InSAR is a new type of single-flight 3D SAR imaging system with the advantages of high coherence and resolution.However,due to the low altitude of the platform,the elevation ambiguity of the system is smaller than the maximal terrain elevation.Since the spatial phase unwrapping is conducted based on the assumption of phase continuity,the inappropriate ambiguity will cause significant unwrapping errors.In this work,a 3D phase unwrapping algorithm assisted by image segmentation is proposed to address this issue.The Markov random field(MRF)is utilized for image segmentation.The optimal spatial phase unwrapping network is achieved based on the segmentation results.The asymptotic 3D phase unwrapping is adopted to get the refined 3D reconstruction.Results based on the real airborne array-InSAR data show that the proposed method effectively improves the elevation ambiguity.展开更多
Multi-baseline synthetic aperture radar interferometry(InSAR),capable of mapping 3D surface model with high precision,is able to overcome the ill-posed problem in the single-baseline InSAR.Current tandem SAR mission u...Multi-baseline synthetic aperture radar interferometry(InSAR),capable of mapping 3D surface model with high precision,is able to overcome the ill-posed problem in the single-baseline InSAR.Current tandem SAR mission utilizes a two-stage global coverage to get the dual-baseline interferograms,which achieves the trade-off between the unwrapping errors and height precision.However,the baseline adjustment will decrease the timeliness of the data acquisition,which is not suitable for monitoring temporal changes of the ground targets.Designing a SAR mission with the single-pass multi-baseline acquisition will improve the practical capability in fast 3D reconstruction.Following the asymptotic 3D phase unwrapping proposed for the airborne array InSAR system,it is possible to get a reliable 3D reconstruction using very sparse acquisitions but the interferograms should follow the optimal baseline configuration.In this article,a new concept of tandem multi-antenna SAR interferometry system for acquiring optimal single-pass multi-baseline interferograms is proposed.Two indicators,i.e.,expected relative height precision and successful phase unwrapping rate,are selected to optimize the system parameters.Additionally,taking the satellites with two antennas as an example,the performances of various baseline configurations in typical scenarios and the impact of different error sources are investigated correspondingly.The simulation-based experiments demonstrate that the proposed system acquires the optimal MB interferograms for asymptotic 3D phase unwrapping,and thus enables good performance in both urban and forest area in a single flight.This system has the potential applications in accurate digital surface model acquisition,3D target recognition,and biomass estimation.展开更多
文摘With the rapid advancement of portable energy devices and sensor technologies,enhancing their catalytic performance,sensing capabilities,and application reliability has become a critical challenge in the fields of materials and energy science.Single-atom catalysts(SACs),owing to their high atomic utilization,outstanding catalytic activity,and precisely engineered structures enabled by density functional theory and enhanced by artificial intelligence,have shown tremendous potential in advancing portable energy and sensing technologies.While existing reviews predominantly focus on the application of SACs in individual portable devices,systematic discussions on their overall development prospects and challenges within portable energy and sensor fields remain scarce.Therefore,this review comprehensively explores the application potential and recent advancements of SACs in portable zinc-air batteries,proton exchange membrane fuel cells,and sensor technologies.The article highlights the influence of key factors such as material design,structural optimization,and packaging integration on device performance,while also addressing the primary bottlenecks and challenges encountered in current practical applications.Furthermore,it suggests possible future development directions,aiming to offer theoretical insights and engineering guidance for the large-scale deployment of SACs in wearable electronic devices,portable energy systems,and smart sensing technologies.
基金supported by The Science and Technology Development Fund,Macao SAR(File No.0037/2018/A1,0026/2020/AGJ)MultiYear Research Grant funded by University of Macao(File No.MYRG2017-00089-FST,MYRG2018-00063-IAPME)。
文摘The wearable sensors have recently attracted considerable attentions as communication interfaces through the information perception,decoding,and conveying process.However,it is still challenging to obtain a sensor that can convert detectable signals into multiple outputs for convenient,e cient,cryptic,and high-capacity information transmission.Herein,we present a capacitive sensor of magnetic field based on a tilted flexible micromagnet array(t-FMA)as the proposed interaction interface.With the bidirectional bending capability of t-FMA actuated by magnetic torque,the sensor can recognize both the magnitude and orientation of magnetic field in real time with non-overlapping capacitance signals.The optimized sensor exhibits the high sensitivity of over 1.3 T-1 and detection limit down to 1 mT with excellent durability.As a proof of concept,the sensor has been successfully demonstrated for convenient,e cient,and programmable interaction systems,e.g.,touchless Morse code and Braille communication.The distinguishable recognition of the magnetic field orientation and magnitude further enables the sensor unit as a high-capacity transmitter for cryptic information interaction(e.g.,encoded ID recognition)and multi-control instruction outputting.We believe that the proposed magnetic field sensor can open up a potential avenue for future applications including information communication,virtual reality device,and interactive robotics.
基金supported in part by the National Natural Foundation of China(No.62201158).
文摘Multi-temporal synthetic aperture radar interferometry(MT-InSAR)is a standard technique for mapping clustering and wide-scale deformation.A linear model is often used in phase unwrapping to overcome the underdetermination.It’s difficult to identify different types of nonlinear deformation.However,the interpretation of nonlinear deformation is very important in monitoring potential risk.This paper introduces a comprehensive approach for identifying and interpreting different types of deformation within InSAR datasets,integrating initial clustering and classification simplification.Initial classification is performed using the K-means clustering method to cluster the collected InSAR deformation time-series data.Then we use F test and Anderson-Darling test(AD test)to simplify the clusters after initial classification.This technique distinctly discerns the changing trends of deformation signals,thereby providing robust support for interpreting potential deformation scenarios within observed InSAR regions.
基金supported by the National Natural Foundation of China(No.62201158).
文摘Synthetic aperture radar(SAR)is able to acquire high-resolution method using the active microwave imaging method.SAR images are widely used in target recognition,classification,and surface analysis,with extracted features.Attribute scattering center(ASC)is able to describe the image features for these tasks.However,sidelobe effects reduce the accuracy and reliability of the estimated ASC model parameters.This paper incorporates the SAR super-resolution into the ASC extraction to improve its performance.Both filter bank and subspace methods are demonstrated for preprocessing to supress the sidelobe.Based on the preprocessed data,a reinforcement based ASC method is used to get the parameters.The experimental results show that the super-resolution method can reduce noise and suppress sidelobe effect,which improve accuracy of the estimated ASC model parameters.
基金supported by Innovation and Strong School Engineering Fund of Guangdong Province(2017KTSCX186,2020KQNCX91,and 2020ZDZX2022)Science and Technology Projects of Jiangmen((2017)307,(2017)149,and(2018)352)+4 种基金Key Laboratory of Optoelectronic materials and Applications in Guangdong Higher Education(2017KSYS011)Science Foundation for Young Teachers of Wuyi University(No.2018td04)Guangdong Basis and Applied Fundamental Research Fund(2019A1515111190)National Natural Science Foundation of China(12004285)Hong Kong and Macao Joint Research and Development Fund of Wuyi University(2019WGALH17).
文摘Flexible sensors in wearable electronics have become increasingly multifunctional due to the development of materials synthesis and structure design.In particular,structural design can not only add capabilities to sensors fabricated from existing available and normal materials,but also offer opportunities for the fabrication of sensors with certain desired functions.Here,we designed a series of fiber-junction structure models,in which two fibers were simply hooked to each other to form a junction on a flexible printed circuit,for fabrication of directional bending sensors.The value and direction of bending angle are related to the change in electronic signal by a theoretical expression,allowing us to employ a simple and practicable method to use available conductive fiber materials to fabricate high-sensitivity,high-resolution and directional bending sensors.In addition,these models are generally applicable,which have broad combination with different conductive fiber,and corresponding bending sensors all possess capability of directional identification.Furthermore,the capability of identifying directional bending was demonstrated by human motion monitoring such as joint bending and muscle contraction.
文摘Unmanned aerial vehicle(UAV)array InSAR is a new type of single-flight 3D SAR imaging system with the advantages of high coherence and resolution.However,due to the low altitude of the platform,the elevation ambiguity of the system is smaller than the maximal terrain elevation.Since the spatial phase unwrapping is conducted based on the assumption of phase continuity,the inappropriate ambiguity will cause significant unwrapping errors.In this work,a 3D phase unwrapping algorithm assisted by image segmentation is proposed to address this issue.The Markov random field(MRF)is utilized for image segmentation.The optimal spatial phase unwrapping network is achieved based on the segmentation results.The asymptotic 3D phase unwrapping is adopted to get the refined 3D reconstruction.Results based on the real airborne array-InSAR data show that the proposed method effectively improves the elevation ambiguity.
基金supported in part by the National Nature Science Foundation of China under grants 61991422 and 62201158.
文摘Multi-baseline synthetic aperture radar interferometry(InSAR),capable of mapping 3D surface model with high precision,is able to overcome the ill-posed problem in the single-baseline InSAR.Current tandem SAR mission utilizes a two-stage global coverage to get the dual-baseline interferograms,which achieves the trade-off between the unwrapping errors and height precision.However,the baseline adjustment will decrease the timeliness of the data acquisition,which is not suitable for monitoring temporal changes of the ground targets.Designing a SAR mission with the single-pass multi-baseline acquisition will improve the practical capability in fast 3D reconstruction.Following the asymptotic 3D phase unwrapping proposed for the airborne array InSAR system,it is possible to get a reliable 3D reconstruction using very sparse acquisitions but the interferograms should follow the optimal baseline configuration.In this article,a new concept of tandem multi-antenna SAR interferometry system for acquiring optimal single-pass multi-baseline interferograms is proposed.Two indicators,i.e.,expected relative height precision and successful phase unwrapping rate,are selected to optimize the system parameters.Additionally,taking the satellites with two antennas as an example,the performances of various baseline configurations in typical scenarios and the impact of different error sources are investigated correspondingly.The simulation-based experiments demonstrate that the proposed system acquires the optimal MB interferograms for asymptotic 3D phase unwrapping,and thus enables good performance in both urban and forest area in a single flight.This system has the potential applications in accurate digital surface model acquisition,3D target recognition,and biomass estimation.
