Cardiac tissue engineering aims to efficiently replace or repair injured heart tissue using scaffolds,relevant cells,or their combination.While the combination of scaffolds and relevant cells holds the potential to ra...Cardiac tissue engineering aims to efficiently replace or repair injured heart tissue using scaffolds,relevant cells,or their combination.While the combination of scaffolds and relevant cells holds the potential to rapidly remuscularize the heart,thereby avoiding the slow process of cell recruitment,the proper ex vivo cellularization of a scaffold poses a substantial challenge.First,proper diffusion of nutrients and oxygen should be provided to the cell-seeded scaffold.Second,to generate a functional tissue construct,cells can benefit from physiological-like conditions.To meet these challenges,we developed a modular bioreactor for the dynamic cellularization of full-thickness cardiac scaffolds under synchronized mechanical and electrical stimuli.In this unique bioreactor system,we designed a cyclic mechanical load that mimics the left ventricle volume inflation,thus achieving a steady stimulus,as well as an electrical stimulus with an action potential profile to mirror the cells’microenvironment and electrical stimuli in the heart.These mechanical and electrical stimuli were synchronized according to cardiac physiology and regulated by constant feedback.When applied to a seeded thick porcine cardiac extracellular matrix(pcECM)scaffold,these stimuli improved the proliferation of mesenchymal stem/stromal cells(MSCs)and induced the formation of a dense tissue-like structure near the scaffold’s surface.Most importantly,after 35 d of cultivation,the MSCs presented the early cardiac progenitor markers Connexin-43 andα-actinin,which were absent in the control cells.Overall,this research developed a new bioreactor system for cellularizing cardiac scaffolds under cardiac-like conditions,aiming to restore a sustainable dynamic living tissue that can bear the essential cardiac excitation–contraction coupling.展开更多
This article focuses on electric power engineering and expounds the development characteristics and applications of new electric power engineering technologies,including technologies such as smart grids and digital de...This article focuses on electric power engineering and expounds the development characteristics and applications of new electric power engineering technologies,including technologies such as smart grids and digital design platforms.It explores the identification and classification of risk elements in electric power engineering and analyzes the deficiencies of traditional risk assessment methods.It introduces the applications of new technologies such as intelligent sensor networks in risk management,proposes a dual-driven model of technology and management,and looks forward to the application prospects of artificial intelligence and blockchain technologies.展开更多
In the field of electric power engineering,due to technological innovation,the evolution of smart grid technology and the access to new energy have changed the system structure,and the characteristics of risks have al...In the field of electric power engineering,due to technological innovation,the evolution of smart grid technology and the access to new energy have changed the system structure,and the characteristics of risks have also evolved.Traditional risk assessment methods and organizational structures are facing challenges.Emerging technologies such as big data and digital twins are applied to risk management.The new paradigm requires the reconstruction of organizational structures and collaborative governance,and involves the construction of a standardized system and ethical norms.展开更多
Silicon(Si)anodes,with a theoretical specific capacity of 4200 mAh g^(-1),hold significant promise for the development of high-energy-density lithium-ion batteries(LIBs).However,practical applications are hindered by ...Silicon(Si)anodes,with a theoretical specific capacity of 4200 mAh g^(-1),hold significant promise for the development of high-energy-density lithium-ion batteries(LIBs).However,practical applications are hindered by sluggish charge transfer kinetics,substantial volume expansion,and an unstable solid elec-trolyte interphase during cycling.To address these challenges,we propose a centimeter-scale Si anode design featuring a three-dimensional continuous network structure of Si nanowires(SiNWs)decorated with high-density Ag nanoparticles(Ag-SiNWs-Net)on both the surface and internally.This architecture effectively mitigates mechanical stress from Si volume changes through the high-aspect-ratio wire network.Additionally,the distribution of Ag nanoparticles on the Si induces electronic structure redistribution,generating built-in electric fields that accelerate charge transfer within the Si,significantly enhancing rate performance and cycling stability.The Ag-SiNWs-Net anode achieves a high reversible capacity of 3780.9 mAh g^(-1)at 0.1 A g^(-1),with an initial coulombic efficiency of 85.1%.Moreover,the energy density of full cells assembled with Ag-SiNWs-Net anodes and LiFePO4 cathodes can be pushed further up to 395.8 Wh kg^(-1).This study offers valuable insights and methodologies for the development of high-capacity and practical Si anodes-.展开更多
The advanced oxidation process presents a perfect solution for eliminating organic pollutants in water resources,and the local microenvironment and surface state of metal reactive sites are crucial for the selective a...The advanced oxidation process presents a perfect solution for eliminating organic pollutants in water resources,and the local microenvironment and surface state of metal reactive sites are crucial for the selective activation of peroxomonosulfate(PMS),which possibly determines the degradation pathways of organic contaminants.In this study,by virtue of the precursor alternation,we constructed the state-switched dual metal species with the porous carbon fibers through the electrospinning strategy.Impressively,the optimal catalyst,featuring the electron-deficient cobalt surface oxidative state and most abundant oxygen vacancies(Ov)with MnO_(2)within porous carbon fibers,provides abundant mesoporosity,facilitating the diffusion and accommodation of big carbamazepine molecules during the reaction process.Benefiting from the tandem configuration of carbon fiber-encapsulated nanocrystalline species,a p-n heterojunction configuration evidenced by Mott-Schottky analysis induced local built-in electric field(BIEF)between electron-deficient cobalt and Ov-rich MnO_(2)within carbon matrix-mediated interfacial interactions,which optimizes the adsorption and activation of PMS and intermediates,increases the concentration of reactive radicals around the active site,and significantly enhances the degradation performance.As a result,the optimal catalyst could achieve 100%degradation of 20 ppm carbamazepine(CBZ)within only 4 min with a rate constant of 1.099 min^(-1),showcasing a low activation energy(50 kJ mol^(-1)),obviously outperforming the other counterparts.We further demonstrated the generation pathways of active species by activation of PMS mainly including sulfate radical(·SO_(4)^(-)),hydroxyl radical(·OH),superoxide radicals(·O_(2)^(-)),and singlet oxygen(^(1)O_(2)),unveiling their contribution to CBZ degradation.The degradation route of CBZ and toxicity analysis of various intermediates were further evaluated.By anchoring the optimal catalyst onto polyester fiber sponge,the photothermal conversion synergistic monolith floatable catalyst and its easy recovery can be achieved,showing good reproducibility and generalizability in the practical application.展开更多
Driven by both the“new engineering”initiative and the energy revolution,the traditional engineering education model can hardly meet the demand of the energy and electric power industry for diversified and interdisci...Driven by both the“new engineering”initiative and the energy revolution,the traditional engineering education model can hardly meet the demand of the energy and electric power industry for diversified and interdisciplinary outstanding engineers.Based on the“industry-university-research-application”four-in-one collaborative education concept,this paper constructs a new training system centered on classified cultivation and classified evaluation.The system aims to solve core problems such as homogeneous training,disconnection between industry and academia,single evaluation method,and insufficient faculty.Through measures including modular courses,the dual-tutor system,and diversified practical platforms,it realizes differentiated and precise talent training,so as to deliver outstanding engineers with the ability to“define problems,break through technologies,and create value”for the energy and electric power industry.展开更多
Flexible pressure sensors have excellent prospects in applications of human-machine interfaces,artificial intelligence and human health monitoring due to their bendable and lightweight characteristics compared to rigi...Flexible pressure sensors have excellent prospects in applications of human-machine interfaces,artificial intelligence and human health monitoring due to their bendable and lightweight characteristics compared to rigid pressure sensors.However,arising from the limited compressibility of soft materials and the hardening of microstructures at the device interface,there is always a trade-off between high sensitivity and broad sensing range for most flexible pressure sensors,which results in a gradual saturation response and limits their practical applications.Herein,inspired by the distinct pressure perception function of crocodile receptors,a highly sensitive and wide-range flexible pressure sensor with multiscale microdomes and interlocked architecture is developed via a facile PS-decorated molding method.Combined with interlocked architecture,the multiscale dome-shaped structured interface enhances the compressibility of the material through structural complementarity,increases the contact area between functional materials,which compensates for the stiffness induced by the deformation of dense microscale columns.This effectively mitigates structural hardening across a wide pressure range,leading to the overall high performance of the sensor.As a result,the obtained sensor exhibits a low detection limit of 5 Pa,a high sensitivity of 6.14 kPa^(-1),a wide measurement range up to 231 kPa,short response/recovery time of 56 ms/69 ms,outstanding stability over 10,000 cycles.Considering these excellent properties,the sensor shows promising potential in health monitoring,human-computer interaction,wearable electronics.This study presents a strategy for the fabrication of flexible pressure sensors exhibiting high sensitivity and a wide pressure response range.展开更多
This paper focuses on electrical fault diagnosis and operation and maintenance technology in property service electromechanical engineering.It details core diagnostic methods,application-oriented tools,predictive main...This paper focuses on electrical fault diagnosis and operation and maintenance technology in property service electromechanical engineering.It details core diagnostic methods,application-oriented tools,predictive maintenance frameworks,and enhanced maintenance planning.It also explores wireless sensor networks,big data analytics,and design-phase applications.Case studies in construction and operation phases are presented.Challenges like legacy system retrofitting are noted,and future potential in quantum sensing and edge AI is discussed.展开更多
Various novel conjugated polymers(CPs)have been developed for organic photodetectors(OPDs),but their application to practical image sensors such as X-ray,R/G/B,and fingerprint sensors is rare.In this article,we report...Various novel conjugated polymers(CPs)have been developed for organic photodetectors(OPDs),but their application to practical image sensors such as X-ray,R/G/B,and fingerprint sensors is rare.In this article,we report the entire process from the synthesis and molecular engineering of novel CPs to the development of OPDs and fingerprint image sensors.We synthesized six benzo[1,2-d:4,5-d’]bis(oxazole)(BBO)-based CPs by modifying the alkyl side chains of the CPs.Several relationships between the molecular structure and the OPD performance were revealed,and increasing the number of linear octyl side chains on the conjugated backbone was the best way to improve Jph and reduce Jd in the OPDs.The optimized CP demonstrated promising OPD performance with a responsivity(R)of 0.22 A/W,specific detectivity(D^(*))of 1.05×10^(13)Jones at a bias of-1 V,rising/falling response time of 2.9/6.9μs,and cut-off frequency(f_(-3dB))of 134 kHz under collimated 530 nm LED irradiation.Finally,a fingerprint image sensor was fabricated by stacking the POTB1-based OPD layer on the organic thin-film transistors(318 ppi).The image contrast caused by the valleys and ridges in the fingerprints was obtained as a digital signal.展开更多
A new Ag/AgCl sensor for measuring marine electric fields was prepared and characterized through electrochemical methods and scanning electron microscopy.Its performance was evaluated in both laboratory and deep-water...A new Ag/AgCl sensor for measuring marine electric fields was prepared and characterized through electrochemical methods and scanning electron microscopy.Its performance was evaluated in both laboratory and deep-water settings.The study indicates that the double-pulse electrodeposition method is advantageous for producing Ag/AgCl sensors that maintain excellent stability over time.During a 20-day continuous stability test,the potential difference of the sensor consistently remained between -24.76μV and 62.07μV,with a minimum potential difference drift of 2.77μV per 24 h.All sensors accurately detected artificial signals in both the time and frequency domains,and their responses were consistent with one another.The minimum noise level of the sensor was 0.59 nV(√Hz)^(-1)@1 Hz.The sensor performed well in high-precision electric field measurements at a depth of approximately 2800 m in the South China Sea.The high stability and low noise level of the sensor make it an effective tool for detecting electrical conductivity structures beneath the seafloor.展开更多
Abstract Advanced crack monitoring technique is the cornerstone of aircraft structural health monitoring. To achieve realtime crack monitoring of aircraft metal structures in the course of ser vice, a new crack monito...Abstract Advanced crack monitoring technique is the cornerstone of aircraft structural health monitoring. To achieve realtime crack monitoring of aircraft metal structures in the course of ser vice, a new crack monitoring method is proposed based on Cu coating sensor and electrical poten tial difference principle. Firstly, insulation treatment process was used to prepare a dielectric layer on structural substrate, such as an anodizing layer on 2AI2T4 aluminum alloy substrate, and then a Cu coating crack monitoring sensor was deposited on the structure fatigue critical parts by pulsed bias arc ion plating technology. Secondly, the damage consistency of the Cu coating sensor and 2A12T4 aluminum alloy substrate was investigated by static tensile experiment and fatigue test. The results show that strain values of the coating sensor and the 2A 12T4 aluminum alloy substrate measured by strain gauges are highly coincident in static tensile experiment and the sensor has excel lent fatigue damage consistency with the substrate. Thirdly, the fatigue performance discrepancy between samples with the coating sensor and original samples was investigated. The result shows that there is no obvious negative influence on the fatigue performance of the 2A12T4 aluminum alloy after preparing the Cu coating sensor on its surface. Finally, crack monitoring experiment was carried out with the Cu coating sensor. The experimental results indicate that the sensor is sensitive to crack, and crack origination and propagation can be monitored effectively through analyzing the change of electrical potential values of the coating sensor.展开更多
The topology and property of Autoassociative Neural Networks(AANN) and theAANN's application to sensor fault diagnosis and reconstruction of engine control system arestudied. The key feature of AANN is feature ext...The topology and property of Autoassociative Neural Networks(AANN) and theAANN's application to sensor fault diagnosis and reconstruction of engine control system arestudied. The key feature of AANN is feature extract and noise filtering. Sensor fault detection isaccomplished by integrating the optimal estimation and fault detection logic. Digital simulationshows that the scheme can detect hard and soft failures of sensors at the absence of models forengines which have performance deteriorate in the service life, and can provide good analyticalredundancy.展开更多
Resolvers are normally employed for rotor positioning in motors for electric vehicles, but resolvers are expensive and vulnerable to vibrations. Hall sensors have the advantages of low cost and high reliability, but t...Resolvers are normally employed for rotor positioning in motors for electric vehicles, but resolvers are expensive and vulnerable to vibrations. Hall sensors have the advantages of low cost and high reliability, but the positioning accuracy is low. Motors with Hall sensors are typically controlled by six-step commutation algorithm, which brings high torque ripple. This paper studies the high-performance driving and braking control of the in-wheel permanent magnetic synchronous motor （PMSM） based on low-resolution Hall sensors. Field oriented control （FOC） based on Hall-effect sensors is developed to reduce the torque ripple. The positioning accuracy of the Hall sensors is improved by interpolation between two consecutive Hall signals using the estimated motor speed. The position error from the misalignment of the Hall sensors is compensated by the precise calibration of Hall transition timing. The braking control algorithms based on six-step commutation and FOC are studied. Two variants of the six-step commutation braking control, namely, half-bridge commutation and full-bridge commutation, are discussed and compared, which shows that the full-bridge commutation could better explore the potential of the back electro-motive forces （EMF）, thus can deliver higher efficiency and smaller current ripple. The FOC braking is analyzed with the phasor diagrams. At a given motor speed, the motor turns from the regenerative braking mode into the plug braking mode if the braking torque exceeds a certain limit, which is proportional to the motor speed. Tests in the dynamometer show that a smooth control could be realized by FOC driving control and the highest efficiency and the smallest current ripple could be achieved by FOC braking control, compared to six-step commutation braking control. Therefore, FOC braking is selected as the braking control algorithm for electric vehicles. The proposed research ensures a good motor control performance while maintaining low cost and high reliability.展开更多
Aircraft engine component and sensor fault detection and isolation approach was proposed,which included fault type detection module and component-sensor simultaneous fault isolation module.The approach can not only di...Aircraft engine component and sensor fault detection and isolation approach was proposed,which included fault type detection module and component-sensor simultaneous fault isolation module.The approach can not only distinguish among sensor fault,component fault and component-sensor simultaneous fault,but also isolate and locate sensor fault and the type of engine component fault when the engine component fault and the sensor faults occur simultaneously.The double-threshold mechanism has been proposed,in which the fault diagnostic threshold changed with the sensor type and the engine condition,and it greatly improved the accuracy and robustness of sensor fault diagnosis system.Simulation results show that the approach proposed can diagnose and isolate the sensor and engine component fault with improved accuracy.It effectively improves the fault diagnosis ability of aircraft engine.展开更多
A novel steady-state optimization （SSO） of internal combustion engine （ICE） strategy is proposed to maximize the efficiency of the overall powertrain for hybrid electric vehicles, in which the ICE efficiency, the ...A novel steady-state optimization （SSO） of internal combustion engine （ICE） strategy is proposed to maximize the efficiency of the overall powertrain for hybrid electric vehicles, in which the ICE efficiency, the efficiencies of the electric motor （EM） and the energy storage device are all explicitly taken into account. In addition, a novel idle optimization of ICE strategy is implemented to obtain the optimal idle operating point of the ICE and corresponding optimal parking generation power of the EM using the view of the novel SSO of ICE strategy. Simulations results show that potential fuel economy improvement is achieved relative to the conventional one which only optimized the ICE efficiency by the novel SSO of ICE strategy, and fuel consumption per voltage increment decreases a lot during the parking charge by the novel idle optimization of ICE strategy.展开更多
As an indispensable branch of wearable electronics,flexible pressure sensors are gaining tremendous attention due to their extensive applications in health monitoring,human-machine interaction,artificial intelligence,...As an indispensable branch of wearable electronics,flexible pressure sensors are gaining tremendous attention due to their extensive applications in health monitoring,human-machine interaction,artificial intelligence,the internet of things,and other fields.In recent years,highly flexible and wearable pressure sensors have been developed using various materials/structures and transduction mechanisms.Morphological engineering of sensing materials at the nanometer and micrometer scales is crucial to obtaining superior sensor performance.This review focuses on the rapid development of morphological engineering technologies for flexible pressure sensors.We discuss different architectures and morphological designs of sensing materials to achieve high performance,including high sensitivity,broad working range,stable sensing,low hysteresis,high transparency,and directional or selective sensing.Additionally,the general fabrication techniques are summarized,including self-assembly,patterning,and auxiliary synthesis methods.Furthermore,we present the emerging applications of high-performing microengineered pressure sensors in healthcare,smart homes,digital sports,security monitoring,and machine learning-enabled computational sensing platform.Finally,the potential challenges and prospects for the future developments of pressure sensors are discussed comprehensively.展开更多
This paper presents a high performance electric field micro sensor with combined differential structure.The sensor consists of two backward laid micro-machined chips,each packaged by polymer and metal.The novel combin...This paper presents a high performance electric field micro sensor with combined differential structure.The sensor consists of two backward laid micro-machined chips,each packaged by polymer and metal.The novel combined differential structure effectively reduces various environmental affections,such as thermal drift,humidity drift and electrostatic charge accumulation.The sensor is tested in near-ground place as well as balloon-borne sounding.In different weather conditions,the measurement results showed good agreement with those of the commercial electric field mill.展开更多
The all traditional electrical resistance tomography (ERT) sensors have a static structure, which cannot satisfy the intelligent requirements for adaptive optimization to ERT sensors that is subject to flow pattern ch...The all traditional electrical resistance tomography (ERT) sensors have a static structure, which cannot satisfy the intelligent requirements for adaptive optimization to ERT sensors that is subject to flow pattern changes during the real-time detection of two-phase flow. In view of this problem, an adaptive ERT sensor with a dynamic structure is proposed. The electrodes of the ERT sensor are arranged in an array structure, the flow pattern recognition technique is introduced into the ERT sensor design and accordingly an ERT flow pattern recognition method based on signal sparsity is proposed. This method uses the sparse representation of the signal to express the sampling voltage of the ERT system as a sparse combination and find its sparse solution to achieve the classification of different flow patterns. With the introduction of flow identification information, the sensor has an intelligent function of adaptively and dynamically adapting the sensor structure according to the real-time flow pattern change. The experimental results show that the sensor can automatically identify four typical flow patterns: core flow, bubble flow, laminar flow and circulation flow with recognition rates of 91%, 93%, 90% and 88% respectively. For different flow patterns, the dynamically optimized sensor can significantly improve the quality of ERT image reconstruction.展开更多
The diamond-like compound Cu_(3)PSe_(4)with low lattice thermal conductivity is deemed to be a promising thermoelectric material,which can directly convert waste heat into electricity or vice versa with no moving part...The diamond-like compound Cu_(3)PSe_(4)with low lattice thermal conductivity is deemed to be a promising thermoelectric material,which can directly convert waste heat into electricity or vice versa with no moving parts and greenhouse emissions.However,its performance is limited by its low electrical conductivity.In this study,we report an effective method to enhance thermoelectric performance of Cu_(3)PSe_(4)by defect engineering.It is found that the carrier concentrations of Cu_(3-x)PSe_(4)(x=0,0.03,0.06,0.09,0.12)compounds are increased by two orders of magnitude as x>0.03,from 1×10^(17)to 1×10^(19)cm^(-3).Combined with the intrinsically low lattice thermal conductivities and enhanced electrical transport performance,a maximum zT value of 0.62 is obtained at 727 K for x=0.12 sample,revealing that Cu defect regulation can be an effective method for enhancing thermoelectric performance of Cu_(3)PSe_(4).展开更多
Increasing energy consumption in the transportation sector results in challenging greenhouse gas(GHG)emissions and environmental problems.This paper involved integrated assessments on GHG emissions and emergy of the l...Increasing energy consumption in the transportation sector results in challenging greenhouse gas(GHG)emissions and environmental problems.This paper involved integrated assessments on GHG emissions and emergy of the life cycle for the internal combustion engine(ICE)and electric automobiles in the USA over the entire assumed fifteen-year lifetime.The hotspots of GHG emissions as well as emergy indices for the major processes of automobile life cycle within the defined system boundaries have been investigated.The potential strategies for reducing GHG emissions and emergy in the life cycle of both ICE and electric automobiles were further proposed.Based on the current results,the total GHG emissions from the life cycle of ICE automobiles are 4.48 E+07 kg CO2-e which is320 times higher than that of the electric automobiles.The hotspot area of the GHG emissions from ICE and electric automobiles are operation phase and manufacturing process,respectively.Interesting results were observed that comparable total emergy of the ICE automobiles and electric automobiles have been calculated which were 1.54 E+17 and 2.20 E+17 sej,respectively.Analysis on emergy index evidenced a better environmental sustainability of electric automobiles than ICE automobiles over the life cycle due to its higher ESI.To the authors’knowledge,it is the first time to integrate the analysis of GHG emissions together with emergy in industrial area of automobile engineering.It is expected that the integration of emergy and GHG emissions analysis may provide a comprehensive perspective on eco-industrial sustainability of automobile engineering.展开更多
基金funded by the Israeli Ministry of Innovation,Science and Technology(Grant No.3-11873)the Israel Science Foundation(Grant No.1563/10)+1 种基金the Randy L.and Melvin R.Berlin Family Research Center for Regenerative Medicinethe Gurwin Family Foundation.
文摘Cardiac tissue engineering aims to efficiently replace or repair injured heart tissue using scaffolds,relevant cells,or their combination.While the combination of scaffolds and relevant cells holds the potential to rapidly remuscularize the heart,thereby avoiding the slow process of cell recruitment,the proper ex vivo cellularization of a scaffold poses a substantial challenge.First,proper diffusion of nutrients and oxygen should be provided to the cell-seeded scaffold.Second,to generate a functional tissue construct,cells can benefit from physiological-like conditions.To meet these challenges,we developed a modular bioreactor for the dynamic cellularization of full-thickness cardiac scaffolds under synchronized mechanical and electrical stimuli.In this unique bioreactor system,we designed a cyclic mechanical load that mimics the left ventricle volume inflation,thus achieving a steady stimulus,as well as an electrical stimulus with an action potential profile to mirror the cells’microenvironment and electrical stimuli in the heart.These mechanical and electrical stimuli were synchronized according to cardiac physiology and regulated by constant feedback.When applied to a seeded thick porcine cardiac extracellular matrix(pcECM)scaffold,these stimuli improved the proliferation of mesenchymal stem/stromal cells(MSCs)and induced the formation of a dense tissue-like structure near the scaffold’s surface.Most importantly,after 35 d of cultivation,the MSCs presented the early cardiac progenitor markers Connexin-43 andα-actinin,which were absent in the control cells.Overall,this research developed a new bioreactor system for cellularizing cardiac scaffolds under cardiac-like conditions,aiming to restore a sustainable dynamic living tissue that can bear the essential cardiac excitation–contraction coupling.
文摘This article focuses on electric power engineering and expounds the development characteristics and applications of new electric power engineering technologies,including technologies such as smart grids and digital design platforms.It explores the identification and classification of risk elements in electric power engineering and analyzes the deficiencies of traditional risk assessment methods.It introduces the applications of new technologies such as intelligent sensor networks in risk management,proposes a dual-driven model of technology and management,and looks forward to the application prospects of artificial intelligence and blockchain technologies.
文摘In the field of electric power engineering,due to technological innovation,the evolution of smart grid technology and the access to new energy have changed the system structure,and the characteristics of risks have also evolved.Traditional risk assessment methods and organizational structures are facing challenges.Emerging technologies such as big data and digital twins are applied to risk management.The new paradigm requires the reconstruction of organizational structures and collaborative governance,and involves the construction of a standardized system and ethical norms.
基金supported by the National Natural Science Foundation of China(No.61904130)the Key Research and Development Program of Hubei Province(Nos.2023BAB122,2021BAA063,and 2020BAB084)the Key Laboratory of Coal Conversion and New Carbon Materials in Hubei Province(No.WKDM201907)for their invaluable support.
文摘Silicon(Si)anodes,with a theoretical specific capacity of 4200 mAh g^(-1),hold significant promise for the development of high-energy-density lithium-ion batteries(LIBs).However,practical applications are hindered by sluggish charge transfer kinetics,substantial volume expansion,and an unstable solid elec-trolyte interphase during cycling.To address these challenges,we propose a centimeter-scale Si anode design featuring a three-dimensional continuous network structure of Si nanowires(SiNWs)decorated with high-density Ag nanoparticles(Ag-SiNWs-Net)on both the surface and internally.This architecture effectively mitigates mechanical stress from Si volume changes through the high-aspect-ratio wire network.Additionally,the distribution of Ag nanoparticles on the Si induces electronic structure redistribution,generating built-in electric fields that accelerate charge transfer within the Si,significantly enhancing rate performance and cycling stability.The Ag-SiNWs-Net anode achieves a high reversible capacity of 3780.9 mAh g^(-1)at 0.1 A g^(-1),with an initial coulombic efficiency of 85.1%.Moreover,the energy density of full cells assembled with Ag-SiNWs-Net anodes and LiFePO4 cathodes can be pushed further up to 395.8 Wh kg^(-1).This study offers valuable insights and methodologies for the development of high-capacity and practical Si anodes-.
基金financially supported by the National Natural Science Foundation of China(No.21908085)the Natural Science Foundation of Jiangsu province(No.BK20241950)+3 种基金China Postdoctoral Science Foundation(No.2023M731422)the Open Project of State Key Laboratory of Materials Chemical Engineering(No.SKL-MCE-23B)Hubei Key Laboratory of Processing and Application of Catalytic materials(No.202441204)the Science and Technology Plan School-Enterprise Cooperation Industry-University-Research Forward-looking Project of Zhangjiagang(No.ZKYY2341)
文摘The advanced oxidation process presents a perfect solution for eliminating organic pollutants in water resources,and the local microenvironment and surface state of metal reactive sites are crucial for the selective activation of peroxomonosulfate(PMS),which possibly determines the degradation pathways of organic contaminants.In this study,by virtue of the precursor alternation,we constructed the state-switched dual metal species with the porous carbon fibers through the electrospinning strategy.Impressively,the optimal catalyst,featuring the electron-deficient cobalt surface oxidative state and most abundant oxygen vacancies(Ov)with MnO_(2)within porous carbon fibers,provides abundant mesoporosity,facilitating the diffusion and accommodation of big carbamazepine molecules during the reaction process.Benefiting from the tandem configuration of carbon fiber-encapsulated nanocrystalline species,a p-n heterojunction configuration evidenced by Mott-Schottky analysis induced local built-in electric field(BIEF)between electron-deficient cobalt and Ov-rich MnO_(2)within carbon matrix-mediated interfacial interactions,which optimizes the adsorption and activation of PMS and intermediates,increases the concentration of reactive radicals around the active site,and significantly enhances the degradation performance.As a result,the optimal catalyst could achieve 100%degradation of 20 ppm carbamazepine(CBZ)within only 4 min with a rate constant of 1.099 min^(-1),showcasing a low activation energy(50 kJ mol^(-1)),obviously outperforming the other counterparts.We further demonstrated the generation pathways of active species by activation of PMS mainly including sulfate radical(·SO_(4)^(-)),hydroxyl radical(·OH),superoxide radicals(·O_(2)^(-)),and singlet oxygen(^(1)O_(2)),unveiling their contribution to CBZ degradation.The degradation route of CBZ and toxicity analysis of various intermediates were further evaluated.By anchoring the optimal catalyst onto polyester fiber sponge,the photothermal conversion synergistic monolith floatable catalyst and its easy recovery can be achieved,showing good reproducibility and generalizability in the practical application.
文摘Driven by both the“new engineering”initiative and the energy revolution,the traditional engineering education model can hardly meet the demand of the energy and electric power industry for diversified and interdisciplinary outstanding engineers.Based on the“industry-university-research-application”four-in-one collaborative education concept,this paper constructs a new training system centered on classified cultivation and classified evaluation.The system aims to solve core problems such as homogeneous training,disconnection between industry and academia,single evaluation method,and insufficient faculty.Through measures including modular courses,the dual-tutor system,and diversified practical platforms,it realizes differentiated and precise talent training,so as to deliver outstanding engineers with the ability to“define problems,break through technologies,and create value”for the energy and electric power industry.
基金supported by the National Natural Science Foundation of China(No.52175269)the Innovative Research Groups of the National Natural Science Foundation of China(No.52021003)+2 种基金Natural Science Foundation of Jilin Province of China(No.20210101052JC)Science and Technology Research Project of Education Department of Jilin Province(JJKH20231146KJ,JJKH20241262KJ)China Postdoctoral Science Foundation(2024M751086).
文摘Flexible pressure sensors have excellent prospects in applications of human-machine interfaces,artificial intelligence and human health monitoring due to their bendable and lightweight characteristics compared to rigid pressure sensors.However,arising from the limited compressibility of soft materials and the hardening of microstructures at the device interface,there is always a trade-off between high sensitivity and broad sensing range for most flexible pressure sensors,which results in a gradual saturation response and limits their practical applications.Herein,inspired by the distinct pressure perception function of crocodile receptors,a highly sensitive and wide-range flexible pressure sensor with multiscale microdomes and interlocked architecture is developed via a facile PS-decorated molding method.Combined with interlocked architecture,the multiscale dome-shaped structured interface enhances the compressibility of the material through structural complementarity,increases the contact area between functional materials,which compensates for the stiffness induced by the deformation of dense microscale columns.This effectively mitigates structural hardening across a wide pressure range,leading to the overall high performance of the sensor.As a result,the obtained sensor exhibits a low detection limit of 5 Pa,a high sensitivity of 6.14 kPa^(-1),a wide measurement range up to 231 kPa,short response/recovery time of 56 ms/69 ms,outstanding stability over 10,000 cycles.Considering these excellent properties,the sensor shows promising potential in health monitoring,human-computer interaction,wearable electronics.This study presents a strategy for the fabrication of flexible pressure sensors exhibiting high sensitivity and a wide pressure response range.
文摘This paper focuses on electrical fault diagnosis and operation and maintenance technology in property service electromechanical engineering.It details core diagnostic methods,application-oriented tools,predictive maintenance frameworks,and enhanced maintenance planning.It also explores wireless sensor networks,big data analytics,and design-phase applications.Case studies in construction and operation phases are presented.Challenges like legacy system retrofitting are noted,and future potential in quantum sensing and edge AI is discussed.
基金funded by the National Research Foundation(NRF)of Korea(2020M3H4A3081816,RS-2023-00304936,and RS-2024-00398065).
文摘Various novel conjugated polymers(CPs)have been developed for organic photodetectors(OPDs),but their application to practical image sensors such as X-ray,R/G/B,and fingerprint sensors is rare.In this article,we report the entire process from the synthesis and molecular engineering of novel CPs to the development of OPDs and fingerprint image sensors.We synthesized six benzo[1,2-d:4,5-d’]bis(oxazole)(BBO)-based CPs by modifying the alkyl side chains of the CPs.Several relationships between the molecular structure and the OPD performance were revealed,and increasing the number of linear octyl side chains on the conjugated backbone was the best way to improve Jph and reduce Jd in the OPDs.The optimized CP demonstrated promising OPD performance with a responsivity(R)of 0.22 A/W,specific detectivity(D^(*))of 1.05×10^(13)Jones at a bias of-1 V,rising/falling response time of 2.9/6.9μs,and cut-off frequency(f_(-3dB))of 134 kHz under collimated 530 nm LED irradiation.Finally,a fingerprint image sensor was fabricated by stacking the POTB1-based OPD layer on the organic thin-film transistors(318 ppi).The image contrast caused by the valleys and ridges in the fingerprints was obtained as a digital signal.
基金supported by the National Natural Science Foundation of China(Nos.U23B20158,91958210,42004055)。
文摘A new Ag/AgCl sensor for measuring marine electric fields was prepared and characterized through electrochemical methods and scanning electron microscopy.Its performance was evaluated in both laboratory and deep-water settings.The study indicates that the double-pulse electrodeposition method is advantageous for producing Ag/AgCl sensors that maintain excellent stability over time.During a 20-day continuous stability test,the potential difference of the sensor consistently remained between -24.76μV and 62.07μV,with a minimum potential difference drift of 2.77μV per 24 h.All sensors accurately detected artificial signals in both the time and frequency domains,and their responses were consistent with one another.The minimum noise level of the sensor was 0.59 nV(√Hz)^(-1)@1 Hz.The sensor performed well in high-precision electric field measurements at a depth of approximately 2800 m in the South China Sea.The high stability and low noise level of the sensor make it an effective tool for detecting electrical conductivity structures beneath the seafloor.
基金co-supported by the National Natural Science Foundation of China(No.51201182)
文摘Abstract Advanced crack monitoring technique is the cornerstone of aircraft structural health monitoring. To achieve realtime crack monitoring of aircraft metal structures in the course of ser vice, a new crack monitoring method is proposed based on Cu coating sensor and electrical poten tial difference principle. Firstly, insulation treatment process was used to prepare a dielectric layer on structural substrate, such as an anodizing layer on 2AI2T4 aluminum alloy substrate, and then a Cu coating crack monitoring sensor was deposited on the structure fatigue critical parts by pulsed bias arc ion plating technology. Secondly, the damage consistency of the Cu coating sensor and 2A12T4 aluminum alloy substrate was investigated by static tensile experiment and fatigue test. The results show that strain values of the coating sensor and the 2A 12T4 aluminum alloy substrate measured by strain gauges are highly coincident in static tensile experiment and the sensor has excel lent fatigue damage consistency with the substrate. Thirdly, the fatigue performance discrepancy between samples with the coating sensor and original samples was investigated. The result shows that there is no obvious negative influence on the fatigue performance of the 2A12T4 aluminum alloy after preparing the Cu coating sensor on its surface. Finally, crack monitoring experiment was carried out with the Cu coating sensor. The experimental results indicate that the sensor is sensitive to crack, and crack origination and propagation can be monitored effectively through analyzing the change of electrical potential values of the coating sensor.
文摘The topology and property of Autoassociative Neural Networks(AANN) and theAANN's application to sensor fault diagnosis and reconstruction of engine control system arestudied. The key feature of AANN is feature extract and noise filtering. Sensor fault detection isaccomplished by integrating the optimal estimation and fault detection logic. Digital simulationshows that the scheme can detect hard and soft failures of sensors at the absence of models forengines which have performance deteriorate in the service life, and can provide good analyticalredundancy.
基金supported by National Hi-tech Research and Development Program of China (863 Program,Grant No.2008AA11A126)Program for New Century Excellent Talents in University of China (Grant No. NCET-10-0498)
文摘Resolvers are normally employed for rotor positioning in motors for electric vehicles, but resolvers are expensive and vulnerable to vibrations. Hall sensors have the advantages of low cost and high reliability, but the positioning accuracy is low. Motors with Hall sensors are typically controlled by six-step commutation algorithm, which brings high torque ripple. This paper studies the high-performance driving and braking control of the in-wheel permanent magnetic synchronous motor （PMSM） based on low-resolution Hall sensors. Field oriented control （FOC） based on Hall-effect sensors is developed to reduce the torque ripple. The positioning accuracy of the Hall sensors is improved by interpolation between two consecutive Hall signals using the estimated motor speed. The position error from the misalignment of the Hall sensors is compensated by the precise calibration of Hall transition timing. The braking control algorithms based on six-step commutation and FOC are studied. Two variants of the six-step commutation braking control, namely, half-bridge commutation and full-bridge commutation, are discussed and compared, which shows that the full-bridge commutation could better explore the potential of the back electro-motive forces （EMF）, thus can deliver higher efficiency and smaller current ripple. The FOC braking is analyzed with the phasor diagrams. At a given motor speed, the motor turns from the regenerative braking mode into the plug braking mode if the braking torque exceeds a certain limit, which is proportional to the motor speed. Tests in the dynamometer show that a smooth control could be realized by FOC driving control and the highest efficiency and the smallest current ripple could be achieved by FOC braking control, compared to six-step commutation braking control. Therefore, FOC braking is selected as the braking control algorithm for electric vehicles. The proposed research ensures a good motor control performance while maintaining low cost and high reliability.
基金Program Sponsored for Scientific Innovation Research of College Graduate in Jiangsu Province(CX10B_108Z)
文摘Aircraft engine component and sensor fault detection and isolation approach was proposed,which included fault type detection module and component-sensor simultaneous fault isolation module.The approach can not only distinguish among sensor fault,component fault and component-sensor simultaneous fault,but also isolate and locate sensor fault and the type of engine component fault when the engine component fault and the sensor faults occur simultaneously.The double-threshold mechanism has been proposed,in which the fault diagnostic threshold changed with the sensor type and the engine condition,and it greatly improved the accuracy and robustness of sensor fault diagnosis system.Simulation results show that the approach proposed can diagnose and isolate the sensor and engine component fault with improved accuracy.It effectively improves the fault diagnosis ability of aircraft engine.
基金National Hi-tech Research end Development Program of China (863 Program,No.2002AA501700,No.2003AA501012)
文摘A novel steady-state optimization （SSO） of internal combustion engine （ICE） strategy is proposed to maximize the efficiency of the overall powertrain for hybrid electric vehicles, in which the ICE efficiency, the efficiencies of the electric motor （EM） and the energy storage device are all explicitly taken into account. In addition, a novel idle optimization of ICE strategy is implemented to obtain the optimal idle operating point of the ICE and corresponding optimal parking generation power of the EM using the view of the novel SSO of ICE strategy. Simulations results show that potential fuel economy improvement is achieved relative to the conventional one which only optimized the ICE efficiency by the novel SSO of ICE strategy, and fuel consumption per voltage increment decreases a lot during the parking charge by the novel idle optimization of ICE strategy.
基金supported by the National Natural Science Foundation of China(52003253 and 52103308)the China Postdoctoral Science Foundation(2020M672283).
文摘As an indispensable branch of wearable electronics,flexible pressure sensors are gaining tremendous attention due to their extensive applications in health monitoring,human-machine interaction,artificial intelligence,the internet of things,and other fields.In recent years,highly flexible and wearable pressure sensors have been developed using various materials/structures and transduction mechanisms.Morphological engineering of sensing materials at the nanometer and micrometer scales is crucial to obtaining superior sensor performance.This review focuses on the rapid development of morphological engineering technologies for flexible pressure sensors.We discuss different architectures and morphological designs of sensing materials to achieve high performance,including high sensitivity,broad working range,stable sensing,low hysteresis,high transparency,and directional or selective sensing.Additionally,the general fabrication techniques are summarized,including self-assembly,patterning,and auxiliary synthesis methods.Furthermore,we present the emerging applications of high-performing microengineered pressure sensors in healthcare,smart homes,digital sports,security monitoring,and machine learning-enabled computational sensing platform.Finally,the potential challenges and prospects for the future developments of pressure sensors are discussed comprehensively.
基金Supported by the National High Technology Research and Development Program of China(863 Program,2011AA-040405)the National Natural Science Foundation of China(Nos.61101049,61201078,61302032,61327810)
文摘This paper presents a high performance electric field micro sensor with combined differential structure.The sensor consists of two backward laid micro-machined chips,each packaged by polymer and metal.The novel combined differential structure effectively reduces various environmental affections,such as thermal drift,humidity drift and electrostatic charge accumulation.The sensor is tested in near-ground place as well as balloon-borne sounding.In different weather conditions,the measurement results showed good agreement with those of the commercial electric field mill.
基金Projects(51405381,51674188)supported by the National Natural Science Foundation of China
文摘The all traditional electrical resistance tomography (ERT) sensors have a static structure, which cannot satisfy the intelligent requirements for adaptive optimization to ERT sensors that is subject to flow pattern changes during the real-time detection of two-phase flow. In view of this problem, an adaptive ERT sensor with a dynamic structure is proposed. The electrodes of the ERT sensor are arranged in an array structure, the flow pattern recognition technique is introduced into the ERT sensor design and accordingly an ERT flow pattern recognition method based on signal sparsity is proposed. This method uses the sparse representation of the signal to express the sampling voltage of the ERT system as a sparse combination and find its sparse solution to achieve the classification of different flow patterns. With the introduction of flow identification information, the sensor has an intelligent function of adaptively and dynamically adapting the sensor structure according to the real-time flow pattern change. The experimental results show that the sensor can automatically identify four typical flow patterns: core flow, bubble flow, laminar flow and circulation flow with recognition rates of 91%, 93%, 90% and 88% respectively. For different flow patterns, the dynamically optimized sensor can significantly improve the quality of ERT image reconstruction.
基金the Graduate Scientific Research and Innovation Foundation of Chongqing,China(No.CYB 19064)the Project for Fundamental and Frontier Research in Chongqing(No.CSTC2017JCYJAX0388)+2 种基金Shenzhen Science and Technology Innovation Committee(No.JCYJ20170818155752559)the National Natural Science Foundation of China(Nos.51772035,11674040 and 51472036)the Fundamental Research Funds for the Central Universities(No.106112017CDJQJ308821)。
文摘The diamond-like compound Cu_(3)PSe_(4)with low lattice thermal conductivity is deemed to be a promising thermoelectric material,which can directly convert waste heat into electricity or vice versa with no moving parts and greenhouse emissions.However,its performance is limited by its low electrical conductivity.In this study,we report an effective method to enhance thermoelectric performance of Cu_(3)PSe_(4)by defect engineering.It is found that the carrier concentrations of Cu_(3-x)PSe_(4)(x=0,0.03,0.06,0.09,0.12)compounds are increased by two orders of magnitude as x>0.03,from 1×10^(17)to 1×10^(19)cm^(-3).Combined with the intrinsically low lattice thermal conductivities and enhanced electrical transport performance,a maximum zT value of 0.62 is obtained at 727 K for x=0.12 sample,revealing that Cu defect regulation can be an effective method for enhancing thermoelectric performance of Cu_(3)PSe_(4).
基金financially supported by National Natural Science Foundation for Young Scientists of China(Grant No.51608531)
文摘Increasing energy consumption in the transportation sector results in challenging greenhouse gas(GHG)emissions and environmental problems.This paper involved integrated assessments on GHG emissions and emergy of the life cycle for the internal combustion engine(ICE)and electric automobiles in the USA over the entire assumed fifteen-year lifetime.The hotspots of GHG emissions as well as emergy indices for the major processes of automobile life cycle within the defined system boundaries have been investigated.The potential strategies for reducing GHG emissions and emergy in the life cycle of both ICE and electric automobiles were further proposed.Based on the current results,the total GHG emissions from the life cycle of ICE automobiles are 4.48 E+07 kg CO2-e which is320 times higher than that of the electric automobiles.The hotspot area of the GHG emissions from ICE and electric automobiles are operation phase and manufacturing process,respectively.Interesting results were observed that comparable total emergy of the ICE automobiles and electric automobiles have been calculated which were 1.54 E+17 and 2.20 E+17 sej,respectively.Analysis on emergy index evidenced a better environmental sustainability of electric automobiles than ICE automobiles over the life cycle due to its higher ESI.To the authors’knowledge,it is the first time to integrate the analysis of GHG emissions together with emergy in industrial area of automobile engineering.It is expected that the integration of emergy and GHG emissions analysis may provide a comprehensive perspective on eco-industrial sustainability of automobile engineering.
