Analyzing the effects of heat rejection from condensers of split-type air-conditioning units at lower-floors of MLABs （multi-level apartment buildings）, using field measurements to monitor environmental conditions a...Analyzing the effects of heat rejection from condensers of split-type air-conditioning units at lower-floors of MLABs （multi-level apartment buildings）, using field measurements to monitor environmental conditions and condenser operation, revealed increases in the inlet air temperature at the condensers at the upper floors, which in turn increased the power and energy requirements for these units and decreased their cooling capacities. Results indicated that a decrease of up to 16,000 tons in cooling capacity and an increase of up to 67.2 MW in the national peak load demand might be reached for a 4 ℃ temperature differential for Kuwait conditions. It is recommended that the condensers be placed in the wind pathway to minimize the impact of heat rejection and stack effect and to optimize the operation of split-type air-conditioning units, and that other factors regarding installation setup and location are investigated.展开更多
Currently,numerous biomimetic robots inspired by natural biological systems have been developed.However,creating soft robots with versatile locomotion modes remains a significant challenge.Snakes,as invertebrate repti...Currently,numerous biomimetic robots inspired by natural biological systems have been developed.However,creating soft robots with versatile locomotion modes remains a significant challenge.Snakes,as invertebrate reptiles,exhibit diverse and powerful locomotion abilities,including prey constriction,sidewinding,accordion locomotion,and winding climbing,making them a focus of robotics research.In this study,we present a snake-inspired soft robot with an initial coiling structure,fabricated using MXene-cellulose nanofiber ink printed on pre-expanded polyethylene film through direct ink writing technology.The controllable fabrication of initial coiling structure soft robot(ICSBot)has been achieved through theoretical calculations and finite element analysis to predict and analyze the initial structure of ICSBot,and programmable ICSBot has been designed and fabricated.This robot functions as a coiling gripper capable of grasping objects with complex shapes under near infrared light stimulation.Additionally,it demonstrates multi-modal crawling locomotion in various environments,including confined spaces,unstructured terrains,and both inside and outside tubes.These results offer a novel strategy for designing and fabricating coiling-structured soft robots and highlight their potential applications in smart and multifunctional robotics.展开更多
Second-generation high-temperature superconducting(2G-HTS)magnets operating in persistent current mode(PCM)hold great promise for applications such as magnetic resonance imaging.The development of joint-less closed-lo...Second-generation high-temperature superconducting(2G-HTS)magnets operating in persistent current mode(PCM)hold great promise for applications such as magnetic resonance imaging.The development of joint-less closed-loop magnets has effectively tackled the challenges of fabricating joints for REBCO tape.However,certain closed-loop magnets cannot utilize conventional persistent current switches(PCS)and instead require multi-pulse magnetization techniques.This study explores the effects of multi-pulse magnetic field excitation on the flux trapping behavior of a four-pancake coil(FPC).A detailed comparison of the effects of different pulse types and periods on the FPC reveals that the background magnetic field exceeds the critical magnetic field of the coil,thereby creating resistance in the superconducting loop.The critical magnetic field of the FPC is determined experimentally,and a reasonable speculation on the multi-pulse field excitation mechanism is presented.展开更多
Biomedical scaffold fabrication has seen advancements in mimicking the native extracellular matrix through intricate three-dimensional(3D)structures conducive to tissue regeneration.Coiled fibrous scaffolds have emerg...Biomedical scaffold fabrication has seen advancements in mimicking the native extracellular matrix through intricate three-dimensional(3D)structures conducive to tissue regeneration.Coiled fibrous scaffolds have emerged as promising substrates owing to their ability to provide unique topographical cues.In this study,coiled poly(ε-caprolactone)(PCL)fibrous bundles were fabricated using an alginate-based composite system,and processed with 3D printing.The unique structure was obtained through the die-swell phenomenon related to the release of residual stresses from the printed strut,thereby transforming aligned PCL fibers into coiled structures.The effects of printing parameters,such as pneumatic pressure and nozzle moving speed,on fiber morphology were investigated to ensure a consistent formation of coiled PCL fibers.The resulting coiled PCL fibrous scaffold demonstrated higher activation of mechanotransduction signaling as well as upregulation of osteogenic-related genes in human adipose stem cells(hASCs),supporting its potential in bone tissue engineering.展开更多
Underwater charging stations allow Autonomous Underwater Vehicles(AUVs)to recharge batteries,extending missions and reducing surface support.However,efficient wireless power transfer requires overcoming alignment chal...Underwater charging stations allow Autonomous Underwater Vehicles(AUVs)to recharge batteries,extending missions and reducing surface support.However,efficient wireless power transfer requires overcoming alignment challenges and environmental variations in conductive seawater.This paper employs Particle Swarm Optimization(PSO)to design coupling coils specifically applied for underwater wireless charging station systems.The establishment of underwater charging stations enables Autonomous Underwater Vehicles(AUVs)to recharge batteries underwater,extending mission duration and reducing reliance on surface-based resupply operations.The proposed charging system is designed to address the unique challenges of the underwater environment,such as alignment disruptions and performance degradation caused by seawater conductivity and environmental fluctuations.Given these distinctive underwater conditions,this study explores coupling coil design comprehensively.COMSOL Multiphysics and MATLAB software were integrated to develop an automated coil evaluation platform,effectively assessing coil coupling under varying misalignment conditions.PSO was employed to optimize coil inner diameters,simulating coupling performance across different misalignment scenarios to achieve high misalignment tolerance.The optimized coils were subsequently implemented in a full-bridge series-series resonant converter and compared with control group coils.Results confirmed the PSO-optimized coils enhanced misalignment resistance,exhibiting a variation of coupling coefficient as low as 4.26%,while the control group coils have a variation of 10.34%.In addition,compared to control group coils,PSO-optimized coils achieved an average efficiency of 71%in air and 67%in seawater,outperforming the control group coils at 66%and 60%,respectively.These findings demonstrate the effectiveness of the proposed PSO-based coil design in improving underwater wireless power transfer reliability and efficiency.展开更多
Endoscopic ultrasound(EUS)guided vascular interventions have expanded the reach of therapeutic endoscopy to include vascular pathology previously inaccessible by endoscopists.Gastric variceal bleeding comprises 20%of ...Endoscopic ultrasound(EUS)guided vascular interventions have expanded the reach of therapeutic endoscopy to include vascular pathology previously inaccessible by endoscopists.Gastric variceal bleeding comprises 20%of all variceal bleeding and is associated with high morbidity and mortality.Historically,endoscopic injection of thrombosis-inducing agents such as glue has been used.However,glue injection carries potential risks including systemic embolization,damage to the endoscope,and recurrent bleeding.The introduction of hemostatic coils has revolutionized the endoscopic approach,with EUS-guided coil embolization emerging as an effective and safe modality for the management of gastric varices(GVs).When compared with conventional glue injection,EUSguided embolization is associated with improved visualization,higher efficacy,and better safety profile.Despite its expanding adoption,the standardization of EUS guided embolization remains a challenge.High-quality studies are needed to standardize this promising technique and define its role in clinical practice.In this review,we will discuss the indications,efficacy,techniques,and various approaches for EUS-guided embolization of GVs.展开更多
A two-dimensional rectangular solenoid transmitting coil is proposed to address the problem that the three-dimensional receiving coil occupies excessive space inside the capsule robot.The transmitting coil consists of...A two-dimensional rectangular solenoid transmitting coil is proposed to address the problem that the three-dimensional receiving coil occupies excessive space inside the capsule robot.The transmitting coil consists of two pairs of rectangular solenoid coils distributed radially along the human body.By changing the direction of current flow,it can generate a two-dimensional magnetic field covering the whole central plane.Firstly,the working mechanism of the wireless power transfer system is introduced,and then the spatial electromagnetic field generated by the transmitting coil is analyzed through both mathematical calculations and finite element simulations.Finally,an experimental platform is built to determine the optimal resonant frequency of the system and validate its feasibility based on the power transfer efficiency and the receiving power.The experimental results demonstrate that when the receiving coil is located at the center of the coil pair,the receiving power is 1416 mW and the power transfer efficiency is 3.96%.Additionally,when the receiving coil operates in the central plane,it can receive sufficient energy regardless of the orientation.展开更多
Gradient coil is an essential component of a magnetic resonance imaging(MRI)scanner.To achieve high spatial resolution and imaging speed,a high-efficiency gradient coil with high slew rate is required.In consideration...Gradient coil is an essential component of a magnetic resonance imaging(MRI)scanner.To achieve high spatial resolution and imaging speed,a high-efficiency gradient coil with high slew rate is required.In consideration of the safety and comfort of the patient,the mechanical stability,acoustic noise and peripheral nerve stimulation(PNS)are also need to be concerned for practical use.In our previous work,a high-efficiency whole-body gradient coil set with a hybrid cylindrical-planar structure has been presented,which offers significantly improved coil performances.In this work,we propose to design this transverse gradient coil system with transformed magnetic gradient fields.By shifting up the zero point of gradient fields,the designed new Y-gradient coil could provide enhanced electromagnetic performances.With more uniform coil winding arrangement,the net torque of the new coil is significantly reduced and the generated sound pressure level(SPL)is lower at most tested frequency bands.On the other hand,the new transverse gradient coil designed with rotated magnetic gradient fields produces considerably reduced electric field in the human body,which is important for the use of rapid MR sequences.It's demonstrated that a safer and patient-friendly design could be obtained by using transformed magnetic gradient fields,which is critical for practical use.展开更多
To address the current issues with the conventional slide gate system utilized in the steel teeming process,a unique electromagnetic induction controlled automated steel teeming(EICAST)technology has been developed.Co...To address the current issues with the conventional slide gate system utilized in the steel teeming process,a unique electromagnetic induction controlled automated steel teeming(EICAST)technology has been developed.Cooling means of spiral coil in this technology is directly related to its service life.Firstly,heat transfer processes of air cooling and spray cooling were compared and analyzed.Secondly,the impacts of water temperature,water flow rate and air flow rate were examined in order to maximize the spray cooling effect.To maintain coil temperature at a low value consistently throughout the entire thermal cycle process of the ladle,a combined cooling mode was finally employed.Numerical simulation was applied to examine the coil temperature variation with different cooling systems and characteristics.Before coil operation,spray cooling is said to be more effective.By controlling the water flow rate and air flow rate,the spray cooling effect is enhanced.However,water temperature has little or no impact when using spray cooling.Air cooling during the secondary refining process and spray cooling prior to coil operation are combined to further lower coil temperature.When the direction of the spray cooling is from bottom to top,the coil temperature is lowered below 165℃.A practical induction coil cooling plan was provided for the EICAST technology’s production process.展开更多
An optimizing method for designing the wireless power receiving coil(RC)is proposed in this paper to address issues such as insufficient and fluctuating power supply in the near-infrared capsule robot.An elec-tromagne...An optimizing method for designing the wireless power receiving coil(RC)is proposed in this paper to address issues such as insufficient and fluctuating power supply in the near-infrared capsule robot.An elec-tromagnetic and circuit analysis is conducted to establish the magnetic induction intensity and equivalent circuit models for the wireless power transmission system.Combining these models involves using the number of layers in each dimension as the optimization variable.Constraints are imposed based on the normalized standard deviation of the receiving-end load power and spatial dimensions.At the same time,the optimization objective aims to maximize the average power of the receiving-end load.This process leads to formulating an optimization model for the RC.Finally,three-dimensional RCs with three different sets of parameters are wound,and the receiving-end load power of these coils is experimentally tested under various drive currents.The experimental values of the receiving-end load power exhibit a consistent trend with theoretical values,with experimental values consistently lower than theoretical values.The optimized coil parameters are determined by conducting comparative exper-iments,with a theoretical value of 4.6%for the normalized standard deviation of the receiving-end load power and an average experimental value of 9.6%.The study addressed the power supply issue of near-infrared capsule robots,which is important for early diagnosing and treating gastrointestinal diseases.展开更多
In traditional meander line coil electromagnetic acoustic transducer(MLC-EMAT)structures,the bias magnetic field is usually set to be along the normal direction of plate surface.However,since the particle vibration of...In traditional meander line coil electromagnetic acoustic transducer(MLC-EMAT)structures,the bias magnetic field is usually set to be along the normal direction of plate surface.However,since the particle vibration of the antisymmetric Lamb wave is always dominated by out-of-plane components,using bias magnetic field perpendicular to plate surface is kind of inefficient.In this paper,the performance of both the normal bias magnetic field EMAT(NB-EMAT)and the parallel bias magnetic field EMAT(PB-EMAT)for transmitting and receiving A0 mode Lamb waves are thoroughly studied.The mechanisms of these two structures are elaborated.First,the finite element models of both structures are established.The magnetic fields of these two EMATs are numerically calculated and the results are compared with experiments.Then,the Lorentz force distributions excited by the two EMATs are compared to prove the feasibility of improving the excitation efficiency of MLC-EMAT by selecting the direction of bias magnetic field.Furthermore,the excitation efficiencies of NB-EMAT and PB-EMAT are quantitatively analyzed and compared in simulation software.Results show that the excitation efficiency of PB-EMAT is 108%higher than NB-EMAT.Finally,several groups of comparative experiments are conducted to verify the conclusion obtained through numerical calculation.Experimental results show that by simply replacing the tradition NB-EMAT with PB-EMAT,the excitation efficiency can be greatly increased by more than 50%.If PB-EMATs are used as both the receiver and transmitter,the excitation efficiency can be further increased by 113%.展开更多
We present a compact cold atom platform where an optical grating chip and planar coil chip are placed inside a compact vacuum chamber to create a magneto-optical trap.This approach significantly reduces the system vol...We present a compact cold atom platform where an optical grating chip and planar coil chip are placed inside a compact vacuum chamber to create a magneto-optical trap.This approach significantly reduces the system volume to about 20×20×20 cm^(3) compared to conventional vacuum systems and offers greater flexibility in accessing the trapped atoms.We demonstrate the trapping of 3×10^(5) cold rubidium atoms at a temperature of 100μK in a vacuum pressure below 10^(−7) mbar.The simplified optical geometry,low power consumption,and high degree of integration make this a promising platform for portable and versatile cold-atom devices in quantum sensing,timing,and information processing.展开更多
Laser-driven ion acceleration,as produced by interaction of a high-intensity laser with a target,is a growing field of interest.One of the current challenges is to enhance the acceleration process,i.e.,to increase the...Laser-driven ion acceleration,as produced by interaction of a high-intensity laser with a target,is a growing field of interest.One of the current challenges is to enhance the acceleration process,i.e.,to increase the produced ion energy and the ion number and to shape the energy distribution for future applications.In this paper,we investigate the effect of helical coil(HC)targets on the laser-matter interaction process using a 150 TW laser.We demonstrate that HC targets significantly enhance proton acceleration,improving energy bunching and beam focusing and increasing the cutoff energy.For the first time,we extend this analysis to carbon ions,revealing a marked reduction in the number of low-energy carbon ions and the potential for energy bunching and post-acceleration through an optimized HC design.Simulations using the particle-in-cell code SOPHIE confirm the experimental results,providing insights into the current propagation and ion synchronization mechanisms in HCs.Our findings suggest that HC targets can be optimized for multispecies ion acceleration.展开更多
文摘Analyzing the effects of heat rejection from condensers of split-type air-conditioning units at lower-floors of MLABs （multi-level apartment buildings）, using field measurements to monitor environmental conditions and condenser operation, revealed increases in the inlet air temperature at the condensers at the upper floors, which in turn increased the power and energy requirements for these units and decreased their cooling capacities. Results indicated that a decrease of up to 16,000 tons in cooling capacity and an increase of up to 67.2 MW in the national peak load demand might be reached for a 4 ℃ temperature differential for Kuwait conditions. It is recommended that the condensers be placed in the wind pathway to minimize the impact of heat rejection and stack effect and to optimize the operation of split-type air-conditioning units, and that other factors regarding installation setup and location are investigated.
基金supported by the National Key R&D Program of China(NO.2024YFB3409900)the China Postdoctoral Science Foundation(NO.2023M730845)the Heilongjiang Postdoctoral Fund(NO.LBH-Z23182)。
文摘Currently,numerous biomimetic robots inspired by natural biological systems have been developed.However,creating soft robots with versatile locomotion modes remains a significant challenge.Snakes,as invertebrate reptiles,exhibit diverse and powerful locomotion abilities,including prey constriction,sidewinding,accordion locomotion,and winding climbing,making them a focus of robotics research.In this study,we present a snake-inspired soft robot with an initial coiling structure,fabricated using MXene-cellulose nanofiber ink printed on pre-expanded polyethylene film through direct ink writing technology.The controllable fabrication of initial coiling structure soft robot(ICSBot)has been achieved through theoretical calculations and finite element analysis to predict and analyze the initial structure of ICSBot,and programmable ICSBot has been designed and fabricated.This robot functions as a coiling gripper capable of grasping objects with complex shapes under near infrared light stimulation.Additionally,it demonstrates multi-modal crawling locomotion in various environments,including confined spaces,unstructured terrains,and both inside and outside tubes.These results offer a novel strategy for designing and fabricating coiling-structured soft robots and highlight their potential applications in smart and multifunctional robotics.
基金Project supported by the National Key Research and Development Program of China(Grant No.2022YFE03150203)the National Natural Science Foundation of China(Grant Nos.U2032217,52072366,and 52477031)Shandong Provincial Natural Science Foundation(Grant No.ZR2024ME217)。
文摘Second-generation high-temperature superconducting(2G-HTS)magnets operating in persistent current mode(PCM)hold great promise for applications such as magnetic resonance imaging.The development of joint-less closed-loop magnets has effectively tackled the challenges of fabricating joints for REBCO tape.However,certain closed-loop magnets cannot utilize conventional persistent current switches(PCS)and instead require multi-pulse magnetization techniques.This study explores the effects of multi-pulse magnetic field excitation on the flux trapping behavior of a four-pancake coil(FPC).A detailed comparison of the effects of different pulse types and periods on the FPC reveals that the background magnetic field exceeds the critical magnetic field of the coil,thereby creating resistance in the superconducting loop.The critical magnetic field of the FPC is determined experimentally,and a reasonable speculation on the multi-pulse field excitation mechanism is presented.
基金supported by the‘Korea National Institute of Health’research project(2022ER130502)a grant from by SMC-SKKU Future Convergence Academic Research Program,2024supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(RS-2024-00336758)。
文摘Biomedical scaffold fabrication has seen advancements in mimicking the native extracellular matrix through intricate three-dimensional(3D)structures conducive to tissue regeneration.Coiled fibrous scaffolds have emerged as promising substrates owing to their ability to provide unique topographical cues.In this study,coiled poly(ε-caprolactone)(PCL)fibrous bundles were fabricated using an alginate-based composite system,and processed with 3D printing.The unique structure was obtained through the die-swell phenomenon related to the release of residual stresses from the printed strut,thereby transforming aligned PCL fibers into coiled structures.The effects of printing parameters,such as pneumatic pressure and nozzle moving speed,on fiber morphology were investigated to ensure a consistent formation of coiled PCL fibers.The resulting coiled PCL fibrous scaffold demonstrated higher activation of mechanotransduction signaling as well as upregulation of osteogenic-related genes in human adipose stem cells(hASCs),supporting its potential in bone tissue engineering.
基金supported by the National Science and Technology Council(NSTC),Taiwan[Project code MOST 110-2222-E-019-005-MY3].
文摘Underwater charging stations allow Autonomous Underwater Vehicles(AUVs)to recharge batteries,extending missions and reducing surface support.However,efficient wireless power transfer requires overcoming alignment challenges and environmental variations in conductive seawater.This paper employs Particle Swarm Optimization(PSO)to design coupling coils specifically applied for underwater wireless charging station systems.The establishment of underwater charging stations enables Autonomous Underwater Vehicles(AUVs)to recharge batteries underwater,extending mission duration and reducing reliance on surface-based resupply operations.The proposed charging system is designed to address the unique challenges of the underwater environment,such as alignment disruptions and performance degradation caused by seawater conductivity and environmental fluctuations.Given these distinctive underwater conditions,this study explores coupling coil design comprehensively.COMSOL Multiphysics and MATLAB software were integrated to develop an automated coil evaluation platform,effectively assessing coil coupling under varying misalignment conditions.PSO was employed to optimize coil inner diameters,simulating coupling performance across different misalignment scenarios to achieve high misalignment tolerance.The optimized coils were subsequently implemented in a full-bridge series-series resonant converter and compared with control group coils.Results confirmed the PSO-optimized coils enhanced misalignment resistance,exhibiting a variation of coupling coefficient as low as 4.26%,while the control group coils have a variation of 10.34%.In addition,compared to control group coils,PSO-optimized coils achieved an average efficiency of 71%in air and 67%in seawater,outperforming the control group coils at 66%and 60%,respectively.These findings demonstrate the effectiveness of the proposed PSO-based coil design in improving underwater wireless power transfer reliability and efficiency.
文摘Endoscopic ultrasound(EUS)guided vascular interventions have expanded the reach of therapeutic endoscopy to include vascular pathology previously inaccessible by endoscopists.Gastric variceal bleeding comprises 20%of all variceal bleeding and is associated with high morbidity and mortality.Historically,endoscopic injection of thrombosis-inducing agents such as glue has been used.However,glue injection carries potential risks including systemic embolization,damage to the endoscope,and recurrent bleeding.The introduction of hemostatic coils has revolutionized the endoscopic approach,with EUS-guided coil embolization emerging as an effective and safe modality for the management of gastric varices(GVs).When compared with conventional glue injection,EUSguided embolization is associated with improved visualization,higher efficacy,and better safety profile.Despite its expanding adoption,the standardization of EUS guided embolization remains a challenge.High-quality studies are needed to standardize this promising technique and define its role in clinical practice.In this review,we will discuss the indications,efficacy,techniques,and various approaches for EUS-guided embolization of GVs.
基金the National Natural Science Foundation of China(Nos.62273225,81971767,62103267 and 62103263)。
文摘A two-dimensional rectangular solenoid transmitting coil is proposed to address the problem that the three-dimensional receiving coil occupies excessive space inside the capsule robot.The transmitting coil consists of two pairs of rectangular solenoid coils distributed radially along the human body.By changing the direction of current flow,it can generate a two-dimensional magnetic field covering the whole central plane.Firstly,the working mechanism of the wireless power transfer system is introduced,and then the spatial electromagnetic field generated by the transmitting coil is analyzed through both mathematical calculations and finite element simulations.Finally,an experimental platform is built to determine the optimal resonant frequency of the system and validate its feasibility based on the power transfer efficiency and the receiving power.The experimental results demonstrate that when the receiving coil is located at the center of the coil pair,the receiving power is 1416 mW and the power transfer efficiency is 3.96%.Additionally,when the receiving coil operates in the central plane,it can receive sufficient energy regardless of the orientation.
基金supported by the Instrument Developing Project of Magnetic Resonance Union of Chinese Academy of Sciences,Grant No.2022GZL002.
文摘Gradient coil is an essential component of a magnetic resonance imaging(MRI)scanner.To achieve high spatial resolution and imaging speed,a high-efficiency gradient coil with high slew rate is required.In consideration of the safety and comfort of the patient,the mechanical stability,acoustic noise and peripheral nerve stimulation(PNS)are also need to be concerned for practical use.In our previous work,a high-efficiency whole-body gradient coil set with a hybrid cylindrical-planar structure has been presented,which offers significantly improved coil performances.In this work,we propose to design this transverse gradient coil system with transformed magnetic gradient fields.By shifting up the zero point of gradient fields,the designed new Y-gradient coil could provide enhanced electromagnetic performances.With more uniform coil winding arrangement,the net torque of the new coil is significantly reduced and the generated sound pressure level(SPL)is lower at most tested frequency bands.On the other hand,the new transverse gradient coil designed with rotated magnetic gradient fields produces considerably reduced electric field in the human body,which is important for the use of rapid MR sequences.It's demonstrated that a safer and patient-friendly design could be obtained by using transformed magnetic gradient fields,which is critical for practical use.
基金supported by the Startup Foundation of Shenyang Agriculture University(No.X2023050)the Fundamental Research Funds for the Central Universities(No.N2209006)the National Natural Science Foundation of China(No.U22A20173).
文摘To address the current issues with the conventional slide gate system utilized in the steel teeming process,a unique electromagnetic induction controlled automated steel teeming(EICAST)technology has been developed.Cooling means of spiral coil in this technology is directly related to its service life.Firstly,heat transfer processes of air cooling and spray cooling were compared and analyzed.Secondly,the impacts of water temperature,water flow rate and air flow rate were examined in order to maximize the spray cooling effect.To maintain coil temperature at a low value consistently throughout the entire thermal cycle process of the ladle,a combined cooling mode was finally employed.Numerical simulation was applied to examine the coil temperature variation with different cooling systems and characteristics.Before coil operation,spray cooling is said to be more effective.By controlling the water flow rate and air flow rate,the spray cooling effect is enhanced.However,water temperature has little or no impact when using spray cooling.Air cooling during the secondary refining process and spray cooling prior to coil operation are combined to further lower coil temperature.When the direction of the spray cooling is from bottom to top,the coil temperature is lowered below 165℃.A practical induction coil cooling plan was provided for the EICAST technology’s production process.
基金the Project of the Science and Technology Commission of Shanghai Municipality(No.20142201300)the National Facility for Translational Medicine(Shanghai)Open Project Foundation(No.TMSK-2021-302)the China Postdoctoral Science Foundation(No.2023M732267)。
文摘An optimizing method for designing the wireless power receiving coil(RC)is proposed in this paper to address issues such as insufficient and fluctuating power supply in the near-infrared capsule robot.An elec-tromagnetic and circuit analysis is conducted to establish the magnetic induction intensity and equivalent circuit models for the wireless power transmission system.Combining these models involves using the number of layers in each dimension as the optimization variable.Constraints are imposed based on the normalized standard deviation of the receiving-end load power and spatial dimensions.At the same time,the optimization objective aims to maximize the average power of the receiving-end load.This process leads to formulating an optimization model for the RC.Finally,three-dimensional RCs with three different sets of parameters are wound,and the receiving-end load power of these coils is experimentally tested under various drive currents.The experimental values of the receiving-end load power exhibit a consistent trend with theoretical values,with experimental values consistently lower than theoretical values.The optimized coil parameters are determined by conducting comparative exper-iments,with a theoretical value of 4.6%for the normalized standard deviation of the receiving-end load power and an average experimental value of 9.6%.The study addressed the power supply issue of near-infrared capsule robots,which is important for early diagnosing and treating gastrointestinal diseases.
基金supported by the Foundation of Guangxi Key Laboratory of Manufacturing System and Advanced Manufacturing Technology(No.17-259-05-005Z)Innovation Project of GUET Graduate Education(No.2025YCXS016)。
文摘In traditional meander line coil electromagnetic acoustic transducer(MLC-EMAT)structures,the bias magnetic field is usually set to be along the normal direction of plate surface.However,since the particle vibration of the antisymmetric Lamb wave is always dominated by out-of-plane components,using bias magnetic field perpendicular to plate surface is kind of inefficient.In this paper,the performance of both the normal bias magnetic field EMAT(NB-EMAT)and the parallel bias magnetic field EMAT(PB-EMAT)for transmitting and receiving A0 mode Lamb waves are thoroughly studied.The mechanisms of these two structures are elaborated.First,the finite element models of both structures are established.The magnetic fields of these two EMATs are numerically calculated and the results are compared with experiments.Then,the Lorentz force distributions excited by the two EMATs are compared to prove the feasibility of improving the excitation efficiency of MLC-EMAT by selecting the direction of bias magnetic field.Furthermore,the excitation efficiencies of NB-EMAT and PB-EMAT are quantitatively analyzed and compared in simulation software.Results show that the excitation efficiency of PB-EMAT is 108%higher than NB-EMAT.Finally,several groups of comparative experiments are conducted to verify the conclusion obtained through numerical calculation.Experimental results show that by simply replacing the tradition NB-EMAT with PB-EMAT,the excitation efficiency can be greatly increased by more than 50%.If PB-EMATs are used as both the receiver and transmitter,the excitation efficiency can be further increased by 113%.
基金supported by the National Key R&D Program(Grant Nos.2021YFA1402004 and 2021YFF0603701)the National Natural Science Foundation of China(Grant Nos.12134014,U21A20433,U21A6006,and 92265108)+1 种基金the Fundamental Research Funds for the Central Universitiesthe University of Science and Technology of China(USTC)Research Funds of the Double First-Class Initiative。
文摘We present a compact cold atom platform where an optical grating chip and planar coil chip are placed inside a compact vacuum chamber to create a magneto-optical trap.This approach significantly reduces the system volume to about 20×20×20 cm^(3) compared to conventional vacuum systems and offers greater flexibility in accessing the trapped atoms.We demonstrate the trapping of 3×10^(5) cold rubidium atoms at a temperature of 100μK in a vacuum pressure below 10^(−7) mbar.The simplified optical geometry,low power consumption,and high degree of integration make this a promising platform for portable and versatile cold-atom devices in quantum sensing,timing,and information processing.
基金supported by the CEA/DAM Laser Plasma Experiments Validation Project and the CEA/DAM Basic Technical and Scientific Studies Projectsupported by the National Sciences and Engineering Research Council of Canada(NSERC)(Grant Nos.RGPIN-2023-05459 and ALLRP 556340-20)+3 种基金the Digital Research Alliance of Canada(Job pve-323-ac)the Canada Foundation for Innovation(CFI)the Ministère de l’Économie,de l’Innovation et de l’Énergie(MEIE)from QuébecThis study was granted access to the HPC resources of IRENE under allocation Grant No.A0170512899 made by GENCI.We acknowledge the financial support of the IdEx University of Bordeaux/Grand Research Program“GPR LIGHT”and of the Graduate Program on Light Sciences and Technologies of the University of Bordeaux.
文摘Laser-driven ion acceleration,as produced by interaction of a high-intensity laser with a target,is a growing field of interest.One of the current challenges is to enhance the acceleration process,i.e.,to increase the produced ion energy and the ion number and to shape the energy distribution for future applications.In this paper,we investigate the effect of helical coil(HC)targets on the laser-matter interaction process using a 150 TW laser.We demonstrate that HC targets significantly enhance proton acceleration,improving energy bunching and beam focusing and increasing the cutoff energy.For the first time,we extend this analysis to carbon ions,revealing a marked reduction in the number of low-energy carbon ions and the potential for energy bunching and post-acceleration through an optimized HC design.Simulations using the particle-in-cell code SOPHIE confirm the experimental results,providing insights into the current propagation and ion synchronization mechanisms in HCs.Our findings suggest that HC targets can be optimized for multispecies ion acceleration.
