In recent years,with the rapid development of unmanned systems technology,unmanned aerial vehicle(UAV)swarm formation flying has gained considerable attention[1,2].Among formation control methods,distributed architect...In recent years,with the rapid development of unmanned systems technology,unmanned aerial vehicle(UAV)swarm formation flying has gained considerable attention[1,2].Among formation control methods,distributed architectures enable the swarm to maintain the shape despite individual UAV failures or communication disruptions,thus demonstrating greater robustness.Moreover,distributed control eliminates reliance on centralized information,yielding a more balanced communication structure across the network[3].展开更多
Vehicle skin is the key component in maintaining the aerodynamic shape of the vehicle.A deformable high-speed vehicle needs to adjust its shape in real time to realize optimum aerodynamic efficiency and to withstand e...Vehicle skin is the key component in maintaining the aerodynamic shape of the vehicle.A deformable high-speed vehicle needs to adjust its shape in real time to realize optimum aerodynamic efficiency and to withstand extreme heat flow induced by high-speed flight,which requires the skin to possess large strain and high-temperature resistance.Traditional vehicle skin cannot satisfy both of the requirements.Biomimetic flexible skin for deformable high-speed vehicles(DHSV-bio-FS)combines flexible material fabrication with transpiration cooling technology,which can simulate human skin sweat cooling,and has the characteristics of large strain and high-temperature resistance.The thermal protection performance of the prepared prototype of DHSV-bio-FS was evaluated by simulation and wind tunnel experiments at 40% tensile strain with liquid water as coolant.Simulation results suggest that the surface temperature of the DHSV-bio-FS at 40% tensile strain is consistent with the temperature of the coolant(350 K)in a 3,000 K high-temperature gas environment.In addition,the prepared prototype DHSV-bio-FS survived for 1,200 s in a high-temperature gas environment of 200 kW/m^(2)in wind tunnel experiments.This paper verifies the reliability of DHSV-bio-FS in a high-temperature gas environment and can be deployed in applications of flexible skin for deformable high-speed vehicles(DHSV-FS).展开更多
Energy resolution is affected by the intrinsic energy resolution of the detector, ballistic deficit, pileup pulses and noise. Pile-up pulses become the dominant factor that degrades energy resolution after the system ...Energy resolution is affected by the intrinsic energy resolution of the detector, ballistic deficit, pileup pulses and noise. Pile-up pulses become the dominant factor that degrades energy resolution after the system is established, so pile-up rejection is often applied to obtain good energy resolution by discarding pulses that are expected to be contaminated by pile-up. However, pile-up rejection can reduce count rates and thus lower the measurement precision. In order to improve count rates and maintain energy resolution, a new method of pile-up pulse identification based on trapezoidal pulse shaping is presented. Combined with pulse width discrimination, this method is implemented by recording pulses that are not seriously piled up. Some experimental tests with a Cu-Pb alloy sample are carried out to verify the performance of this method in X-ray spectrometry. The results show that the method can significantly improve count rates without degrading energy resolution.展开更多
A cross-shaped photonic crystal waveguide formed by a square lattice Al_2O_3 rods array is numerically and experimentally investigated. The band gap of the TE mode for the photonic crystals and transmission characteri...A cross-shaped photonic crystal waveguide formed by a square lattice Al_2O_3 rods array is numerically and experimentally investigated. The band gap of the TE mode for the photonic crystals and transmission characteristics of waveguides are calculated by the plane wave expansion method and the finite element method.We perform the experiments in the microwave regime to validate the numerical results. The measured reflection and transmission characteristics of the photonic crystals show a large band gap between 8.62 and 11.554 GHz（relative bandwidth is 29.34%）. The electromagnetic waves are transmitted stably in the waveguides, and the transmission characteristics maintain a high level in the band gap.展开更多
Small-scale soft robots with high morphological flexibility show significant potential for precise operation and sensing in confined environments.However,due to the coupled driving mechanism and the influence of envir...Small-scale soft robots with high morphological flexibility show significant potential for precise operation and sensing in confined environments.However,due to the coupled driving mechanism and the influence of environmental disturbances,the highly adaptable and stable navigation across diverse terrains through multimodal motion,which involves morphing shape and maintaining the reshaped configuration,still presents a major challenge for soft millirobots.展开更多
基金supported by Guangdong Basic and Applied Basic Research Foundation(Grant No.2023B1515120018)Shenzhen Fundamental Research Program(Grant Nos.JCYJ20241202124010014 and GXWD20231129140908002)。
文摘In recent years,with the rapid development of unmanned systems technology,unmanned aerial vehicle(UAV)swarm formation flying has gained considerable attention[1,2].Among formation control methods,distributed architectures enable the swarm to maintain the shape despite individual UAV failures or communication disruptions,thus demonstrating greater robustness.Moreover,distributed control eliminates reliance on centralized information,yielding a more balanced communication structure across the network[3].
基金supported by the Major Research Plan of the National Natural Science Foundation of China(Grant No.92271201)the Natural Science Basic Research Program of Shaanxi(Program No.2024JC-JCQN-61).
文摘Vehicle skin is the key component in maintaining the aerodynamic shape of the vehicle.A deformable high-speed vehicle needs to adjust its shape in real time to realize optimum aerodynamic efficiency and to withstand extreme heat flow induced by high-speed flight,which requires the skin to possess large strain and high-temperature resistance.Traditional vehicle skin cannot satisfy both of the requirements.Biomimetic flexible skin for deformable high-speed vehicles(DHSV-bio-FS)combines flexible material fabrication with transpiration cooling technology,which can simulate human skin sweat cooling,and has the characteristics of large strain and high-temperature resistance.The thermal protection performance of the prepared prototype of DHSV-bio-FS was evaluated by simulation and wind tunnel experiments at 40% tensile strain with liquid water as coolant.Simulation results suggest that the surface temperature of the DHSV-bio-FS at 40% tensile strain is consistent with the temperature of the coolant(350 K)in a 3,000 K high-temperature gas environment.In addition,the prepared prototype DHSV-bio-FS survived for 1,200 s in a high-temperature gas environment of 200 kW/m^(2)in wind tunnel experiments.This paper verifies the reliability of DHSV-bio-FS in a high-temperature gas environment and can be deployed in applications of flexible skin for deformable high-speed vehicles(DHSV-FS).
基金Supported by National Natural Science Foundation of China(11475036,41404108)
文摘Energy resolution is affected by the intrinsic energy resolution of the detector, ballistic deficit, pileup pulses and noise. Pile-up pulses become the dominant factor that degrades energy resolution after the system is established, so pile-up rejection is often applied to obtain good energy resolution by discarding pulses that are expected to be contaminated by pile-up. However, pile-up rejection can reduce count rates and thus lower the measurement precision. In order to improve count rates and maintain energy resolution, a new method of pile-up pulse identification based on trapezoidal pulse shaping is presented. Combined with pulse width discrimination, this method is implemented by recording pulses that are not seriously piled up. Some experimental tests with a Cu-Pb alloy sample are carried out to verify the performance of this method in X-ray spectrometry. The results show that the method can significantly improve count rates without degrading energy resolution.
基金supported by the National Natural Science Foundation of China under Grant No.61171006
文摘A cross-shaped photonic crystal waveguide formed by a square lattice Al_2O_3 rods array is numerically and experimentally investigated. The band gap of the TE mode for the photonic crystals and transmission characteristics of waveguides are calculated by the plane wave expansion method and the finite element method.We perform the experiments in the microwave regime to validate the numerical results. The measured reflection and transmission characteristics of the photonic crystals show a large band gap between 8.62 and 11.554 GHz（relative bandwidth is 29.34%）. The electromagnetic waves are transmitted stably in the waveguides, and the transmission characteristics maintain a high level in the band gap.
基金supported by the National Natural Science Foundation of China under grant numbers 62222305,62088101,and U22A2064the Beijing Natural Science Foundation under grant L242023the Fundamental Research Funds for the Central Universities under grants 2025CX01003 and 2024CX06008.
文摘Small-scale soft robots with high morphological flexibility show significant potential for precise operation and sensing in confined environments.However,due to the coupled driving mechanism and the influence of environmental disturbances,the highly adaptable and stable navigation across diverse terrains through multimodal motion,which involves morphing shape and maintaining the reshaped configuration,still presents a major challenge for soft millirobots.
