Quantum dot(QD)-based fluorescent inks offer high potential due to their tunable emission and high quantum yield,but their practical application suffers from poor environmental stability,aggregation,and challenges in ...Quantum dot(QD)-based fluorescent inks offer high potential due to their tunable emission and high quantum yield,but their practical application suffers from poor environmental stability,aggregation,and challenges in scalable flexible fabrication.In this study,a high-stability fluorescent ink was developed by incorporating QDs into a polydimethylsiloxane(PDMS)colloidal matrix.High-performance patterned films were then obtained via systematic optimization of screen-printing parameters,with film quality governed by substrate type(131μm PDMS),QD concentration(1.5 mg/mL),and screen mesh count(420 mesh).The optimized films exhibit outstanding environmental and photostability,retaining 75.6% of their fluorescence intensity after immersion in deionized water and 63.8% in 75%ethanol at 25℃ for 100 minutes.Under UV irradiation(365 nm,9 W,100 min),fluorescence intensity decreases by less than 20%.Utilizing their daylight transparency and UV-excitable luminescence,various patterns including QR codes and Code 93 standard barcodes were fabricated via screen printing with high pattern fidelity and machine readability.This study presents a scalable and reliable strategy for the fabrication of flexible,high-stability fluorescent films,supporting their integration into next-generation optoelectronic devices,advanced displays,and secure anti-counterfeiting.展开更多
This work pioneers a transient electrical explosive flexible igniter based on a polyurethane-copper composite,achieving unprecedented microsecond-scale plasma initiation(0.75μs threshold at 30 V)through key innovatio...This work pioneers a transient electrical explosive flexible igniter based on a polyurethane-copper composite,achieving unprecedented microsecond-scale plasma initiation(0.75μs threshold at 30 V)through key innovations.A dual-V geometric design concentrating current density.Electroless copper plating(ECP)enabling 80μm conductive layers with flexibility.Capacitive discharge optimization for tunable energy delivery(0.058–1.088 mJ).The flexible architecture demonstrates remarkable mechanical-electrical decoupling-maintaining functionality under 140 kg compressive loads(250%improvement over rigid igniters)and 90°torsional deformation while delivering consistent plasma jets(3–5 mm height,180–580μs duration).Based on the analysis of the multi-physics field simulation re-sults,multiphase energy conversion occurs during the electrical explosion process.The initial Joule heating reaches the melting point of copper,and then an electrical explosion plasma is generated.Voltage-dependent studies identify 50 V as the critical threshold for performance leap,where peak current increases 46.56%and plasma duration extends 214.29%versus 30 V operation.These advances establish a new class of high-speed ignition systems combiningμs-response,140 kg shock resistance,and conformal deployment capabilities for next-generation munitions and micro-propulsion applications.This work extends the application of flexible electronics to the field of transient ignition.展开更多
To address efficient operation scheduling of shipboard helicopter groups under multi-mission demands and limited deck space,a novel Flexible Operation Mode(FOM)was proposed.Mission grouping,deck operation processes,an...To address efficient operation scheduling of shipboard helicopter groups under multi-mission demands and limited deck space,a novel Flexible Operation Mode(FOM)was proposed.Mission grouping,deck operation processes,and mission time were flexibilized to construct a mission planning method.From the perspective of the deck operation lifecycle,the scheduling problem was modeled as a six-stage mixed-integer program.A bi-level optimization framework was introduced,prioritizing maximization of mission time window satisfaction and secondarily minimizing mean deck operation time.Spatial evolution during the transportation phase was managed via an offline trajectory library that converted high-dimensional constraints into low-dimensional parameter mappings,significantly reducing real-time solution complexity.A Leader-Follower Particle Swarm Optimization(LFPSO)algorithm was developed,featuring a three-stage stochastic priority encoding and a mission-chain-driven launch-re-covery decoupling strategy to reduce decision coupling.A hierarchical population structure enhanced co-evolution of global search and local refinement.The case simulation results show that the proposed model and algorithm can effectively solve the deck operation scheduling problem in complex mission scenarios,and are significantly superior to the Continuous Operation Mode(COM)and the Fixed-process FOM(FFOM)in key performance indicators such as mission time window satisfaction,average deck operation time,and average mission flight time.Its effectiveness in enhancing system scheduling capability and performance stability has been verified.This research provides systematic support for the flexible construction and intelligent decision-making of ship aviation operation systems.展开更多
Stretchable polymer semiconductor film(SPSF)is the core to fabricate the flexible optoelectronic devices,due to its excellent strain-tolerance capacity.Softness of polymer chain realized via introducing flexible segme...Stretchable polymer semiconductor film(SPSF)is the core to fabricate the flexible optoelectronic devices,due to its excellent strain-tolerance capacity.Softness of polymer chain realized via introducing flexible segment at the backbone and side-substituents is the effective strategy to obtain SPSFs,but easily causing the relatively instable film morphology and weak energy dissipation ability.Herein,we proposed a convenient side-chain cross-linked strategy to prepare the stretchable SPSF with an outstanding morphological stability for flexible polymer light-emitting diodes(PLED).Styrene group is introduced as ended cross-linking unit into the side chain of fluorene to prepare the intrinsically stretchable alter-copolymers semiconductors poly(9,9-diphenyl-4-((6-(4-vinylphenoxy)hexyl)oxy)-9 H-fluorene)-alt(1,8-bis(4-phenoxy)octane)(PCm-alt-C8).Interestingly,PCm-alt-C8 cross-linked film easily obtained via thermal treatment at 180℃,had stable morphology,excellent solvent resistance and deep-blue emission simultaneously.Compared to the controlled PEt-alt-C8,PCm-alt-C8 cross-linked films also present an excellent strain-tolerance capacity with larger crack initiation strain rates and the elongation at break(both enhanced by about 90%).More important,stretchable PCm-alt-C8 cross-linked films showed a stable electroluminescent and electrical property with large stretching degree(>30%)and hundreds of cycles of cycling stretch deformations,suggesting their excellent strain tolerance capacity.Therefore,side-chain cross-linking is a universal strategy for the preparation of high-performance SPSF in flexible optoelectronics.展开更多
For rechargeable aqueous zinc-ion batteries(ZIBs),the design of nanocomposites comprised of electrochemically active materials and carbon materials with novel structures has great prom-ise in addressing the issue of e...For rechargeable aqueous zinc-ion batteries(ZIBs),the design of nanocomposites comprised of electrochemically active materials and carbon materials with novel structures has great prom-ise in addressing the issue of electrical conductivity and structural stability in the electrode materials during electrochemical cycling.We report the production of a novel flexible electrode material,by anchoring MnO_(2) nanosheets on a B,N co-doped carbon nanotube ar-ray(BNCNTs)grown on carbon cloth(BNCNTs@MnO_(2)),which was fabricated by in-situ pyrolysis and hydrothermal growth.The generated BNCNTs were strongly bonded to the surface of the car-bon fibers in the carbon cloth which provides both excellent elec-tron transport and ion diffusion,and improves the stability and dur-ability of the cathode.Importantly,the BNCNTs offer more active sites for the hydrothermal growth of MnO_(2),ensuring a uniform dis-tribution.Electrochemical tests show that BNCNTs@MnO_(2) delivers a high specific capacity of 310.7 mAh g^(−1) at 0.1 A g^(−1),along with excellent rate capability and outstanding cycling stability,with a 79.7% capacity retention after 8000 cycles at 3 A g^(−1).展开更多
Electrospinning technology has emerged as a promising method for fabricating flexible lithium-ion batter-ies(FLIBs)due to its ability to create materials with desir-able properties for energy storage applications.FLIB...Electrospinning technology has emerged as a promising method for fabricating flexible lithium-ion batter-ies(FLIBs)due to its ability to create materials with desir-able properties for energy storage applications.FLIBs,which are foldable and have high energy densities,are be-coming increasingly important as power sources for wear-able devices,flexible electronics,and mobile energy applica-tions.Carbon materials,especially carbon nanofibers,are pivotal in improving the performance of FLIBs by increas-ing electrical conductivity,chemical stability,and surface area,as well as reducing costs.These materials also play a significant role in establishing conducting networks and im-proving structural integrity,which are essential for extend-ing the cycle life and enhancing the safety of the batteries.This review considers the role of electrospinning in the fabrication of critical FLIB components,with a particular emphasis on the integration of carbon materials.It explores strategies to optimize FLIB performance by fine-tuning the electrospinning para-meters,such as electric field strength,spinning rate,solution concentration,and carbonization process.Precise control over fiber properties is crucial for enhancing battery reliability and stability during folding and bending.It also highlights the latest research findings in carbon-based electrode materials,high-performance electrolytes,and separator structures,discussing the practical challenges and opportunities these materials present.It underscores the significant impact of carbon materials on the evolution of FLIBs and their potential to shape future energy storage technologies.展开更多
Reusable and flexible capturing of space debris is highly required in future aerospace technologies.A tendon-actuated flexible robotic arm is therefore proposed for capturing floating targets in this paper.Firstly,an ...Reusable and flexible capturing of space debris is highly required in future aerospace technologies.A tendon-actuated flexible robotic arm is therefore proposed for capturing floating targets in this paper.Firstly,an accurate dynamic model of the flexible robotic arm is established by using the absolute nodal coordinate formulation(ANCF)in the framework of the arbitrary Lagrangian-Eulerian(ALE)description and the natural coordinate formulation(NCF).The contact and self-contact dynamics of the flexible robotic arm when bending and grasping an object are considered via a fast contact detection approach.Then,the dynamic simulations of the flexible robotic arm for capturing floating targets are carried out to study the influence of the position,size,and mass of the target object on the grasping performance.Finally,a principle prototype of the tendon-actuated flexible robotic arm is manufactured to validate the dynamic model.The corresponding grasping experiments for objects of various shapes are also conducted to illustrate the excellent performance of the flexible robotic arm.展开更多
The increase in aerodynamic drag brings high energy consumption,which is a critical issue in the development of high-speed trains.Inspired by the excellent hydrodynamic characteristics of fish movement in nature,a two...The increase in aerodynamic drag brings high energy consumption,which is a critical issue in the development of high-speed trains.Inspired by the excellent hydrodynamic characteristics of fish movement in nature,a two-dimensional numerical simulation method based on spring-smoothing model and adaptive mesh technology was utilized to explore the effects of different fishtail structures and two flexible motion modes(Eel mode and Lunate-tail mode)on the wake of high-speed trains,and to assess their potential for aerodynamic drag reduction.Results indicate that the biomimetic fishtail successfully suppresses the alternating shedding of vortices in the wake,and induces the aerodynamic drag fluctuation period to align with the fishtail oscillation period.The fishtail length,oscillation mode,and frequency have a significant impact on the wake flow and aerodynamic drag of the train.Among these,a 1850 mm Eel fishtail with parameters ofλ=1 and T=8 s achieves the optimal drag reduction effect,with drag reduction rates of 39.12%and 26.00%for the tail car and the entire train,respectively.These findings provide a theoretical basis for the design of new low-resistance railway trains,promoting the sustainable development of rail transit towards goals of high-speed and energy-efficient.展开更多
Urban growth has promoted the use of underground spaces,where explosion accidents can be catastrophic.In this study,we investigated the effect of placing flexible construction in front of rigid obstacles on methane ex...Urban growth has promoted the use of underground spaces,where explosion accidents can be catastrophic.In this study,we investigated the effect of placing flexible construction in front of rigid obstacles on methane explosion protection by using an experimental platform and adjusting the blockage rate and spacing of the obstacles.It aims to reduce the risk of gas explosions in urban underground spaces.The results of the study show that the flame propagation peak speed and peak overpressure are reduced with the decrease in the blocking rate of the flexible obstacle when the blocking rate of the flexible obstacle is less than or equal to the blocking rate of the rigid obstacle,with the decrease in the spacing,the better the protection effect of the methane explosion.When the blockage rate of the flexible obstacle is greater than the blockage rate of the rigid obstacle and spacing is less than the height of the flexible obstacle,rigid and flexible obstacles are connected as a whole,increasing the strength of the explosion.This study can provide a theoretical basis and scientific guidance for optimizing rigid and flexible object hybrid layouts and methane explosion protection technology in urban underground spaces.展开更多
Flexible microporous metal rubber(FMP-MR)is widely used in national defense applications,yet its mechanical behavior under high-speed impact conditions remains insufficiently explored.In this study,dynamic and static ...Flexible microporous metal rubber(FMP-MR)is widely used in national defense applications,yet its mechanical behavior under high-speed impact conditions remains insufficiently explored.In this study,dynamic and static experiments were conducted to systematically investigate the mechanical response of metal-wrapped microporous materials under impact loading that spanned 10~6 orders of magnitude.By combining a high-precision numerical model with a spatial contact point search algorithm,the spatio–temporal contact characteristics of the complex network structure in FMP-MR were systematically analyzed.Furthermore,the mapping mechanism from turn topology and mesoscopic friction behavior to macroscopic mechanical properties was comprehensively explored.The results showed that compared with quasi-static loading,FMP-MR under high-speed impact exhibited higher energy absorption efficiency due to high-strain-rate inertia effect.Therefore,the peak stress increased by 141%,and the maximum energy dissipation increased by 300%.Consequently,the theory of dynamic friction locking effect was innovatively proposed.The theory explains that the close synergistic effect of sliding friction and plastic dissipation promoted by the stable interturn-locked embedded structure is the essential reason for the excellent dynamic mechanical properties of FMP-MR under dynamic loading conditions.Briefly,based on the in-depth investigation of the mechanical response and energy dissipation mechanism of FMP-MR under impact loads,this study provides a solid theoretical basis for further expanding the application range of FMP-MR and optimizing its performance.展开更多
目的探讨Supreme喉罩和Flexible喉罩不同通气罩内压对气道漏气压的影响。方法择期全麻乳腺手术患者,根据插入喉罩种类不同分为Supreme组(35例)和Flexible组(33例)。常规静脉麻醉诱导后由同一麻醉科医师插入Supreme或Flexible喉罩,确认...目的探讨Supreme喉罩和Flexible喉罩不同通气罩内压对气道漏气压的影响。方法择期全麻乳腺手术患者,根据插入喉罩种类不同分为Supreme组(35例)和Flexible组(33例)。常规静脉麻醉诱导后由同一麻醉科医师插入Supreme或Flexible喉罩,确认位置良好,调整通气罩压力。分别记录通气罩压力为10、20、30、40、50 cm H2O(1 cm H2O=0.098 k Pa)时,两种喉罩的气道漏气压值。结果 Supreme组通气罩内压力20、30、40、50 cm H2O时,所对应的气道漏气压差异无统计学意义(P>0.05),但均显著高于10 cm H2O时气道漏气压(P<0.05);Flexible组通气罩内压力为30、40、50 cm H2O时,所对应的气道漏气压差异无统计学意义(P>0.05),但高于10、20 cm H2O时气道漏气压(P<0.05)。Supreme组患者的整体平均气道漏气压(25.40±5.52)cm H2O明显高于Flexible组的(20.67±3.06)cm H2O(P<0.05)。结论 Supreme喉罩的平均气道漏气压高于Flexible喉罩,达到最大平均气道漏气压时,Supreme喉罩所需的通气罩内压(20 cm H2O)低于Flexible喉罩(30 cm H2O)。展开更多
The dynamics of spatial parallel manipulator with rigid and flexible links is explored. Firstly, a spatial beam element model for finite element analysis is established. Then, the differential equation of motion of be...The dynamics of spatial parallel manipulator with rigid and flexible links is explored. Firstly, a spatial beam element model for finite element analysis is established. Then, the differential equation of motion of beam element is derived based on finite element method. The kinematic constraints of parallel manipulator with rigid and flexible links are obtained by analyzing the motive parameters of moving platform and the relationships of movements of kinematic chains, and the overall kinetic equation of the parallel mechanism with rigid and flexible links is derived by assembling the differential equations of motion of components. On the basis of abovementioned analyses, the dynamic mechanical analysis of the spatial parallel manipulator with rigid and flexible links is conducted. After obtaining the method for force analysis and expressions for the calculation of dynamic stress of flexible components, the dynamic analysis and simulation of spatial parallel manipulator with rigid and flexible links is performed. The result shows that because of the elastic deformation of flexible components in the parallel mechanism with rigid and flexible links, the force on each component in the mechanism fluctuates sharply, and the change of normal stress at the root of drive components is also remarkable. This study provides references for further studies on the dynamic characteristics of parallel mechanisms with rigid and flexible links and for the optimization of the design of the mechanism.展开更多
The focus of this paper is on control design and simulation for the longitudinal model of a flexible air-breathing hypersonic vehicle（FAHV）.The model of interest includes flexibility effects and intricate couplings ...The focus of this paper is on control design and simulation for the longitudinal model of a flexible air-breathing hypersonic vehicle（FAHV）.The model of interest includes flexibility effects and intricate couplings between the engine dynamics and flight dynamics.To overcome the analytical intractability of this model,a nominal control-oriented model is constructed for the purpose of feedback control design in the first place.Secondly,the multi-input multi-output（MIMO） quasi-continuous high-order sliding mode（HOSM） controller is proposed to track step changes in velocity and altitude,which is based on full state feedback.The simulation results are presented to verify the effectiveness of the proposed control strategy.展开更多
Planet gear systems(PGSs)are key components of transmission mechanisms.Structural and material characteristics of gearbox and shaft can affect the support stiffness and vibrations of PGSs.The ring gear flexibility sho...Planet gear systems(PGSs)are key components of transmission mechanisms.Structural and material characteristics of gearbox and shaft can affect the support stiffness and vibrations of PGSs.The ring gear flexibility should affect the vibrations of PGSs too.However,most previous work did not completely consider the effects of the ring gear flexibility on the vibrations of PGSs and flexible supports of ring and sun gears.Thus,this paper presents a flexible-rigid coupling multi-body dynamic(FMBD)model for a PGS with the flexible supports and ring gear flexibility.A finite element model of ring gear is established to formulate the ring gear flexibility.The influences of clearance and damping of planet bearings on the vibrations of PGS are considered.The effects of flexible supports and ring gear flexibility on the vibrations of PGS under different moment and speed conditions are studied.The statistical parameters and peak frequencies of PGS from the proposed FMBD and previous rigid multi-body dynamic(RMBD)models are compared.The results denote that the flexible support has a great effect on the vibrations of PGS.This paper can provide some guidance for the support structure design and vibration control for PGSs.展开更多
The issue of attitude maneuver of a flexible spacecraft is investigated with single gimbaled control moment gyroscopes （SGCMGs） as an actuator. To solve the inertia uncertainty of the system, an adaptive attitude co...The issue of attitude maneuver of a flexible spacecraft is investigated with single gimbaled control moment gyroscopes （SGCMGs） as an actuator. To solve the inertia uncertainty of the system, an adaptive attitude control algorithm is designed by applying a radial basis function （RBF） neural network. An improved steering law for SGCMGs is proposed to achieve the optimal out- put torque. It enables the SGCMGs not only to avoid singularity, but also to output more precise torque. In addition, global, uniform, ultimate bounded stability of the attitude control system is proved via the Lyapunov technique. Simulation results demonstrate the effectiveness of the new steering law and the algorithm of attitude maneuver of the flexible spacecraft.展开更多
A new kind of flexible pneumatic wall-climbing robot,named WALKMAN-I,was proposed. WALKMAN-I is basically composed of a flexible pneumatic actuator (FPA),a flexible pneumatic spherical joint and six suction cups. It h...A new kind of flexible pneumatic wall-climbing robot,named WALKMAN-I,was proposed. WALKMAN-I is basically composed of a flexible pneumatic actuator (FPA),a flexible pneumatic spherical joint and six suction cups. It has many characteristics of low-cost,lightweight,simple structure and good flexibility. Its operating principle was introduced. Then three basic locomotion modes,which are linear motion,curvilinear motion and crossing the orthogonal planes,were presented. The safety conditions of WALKMAN-I were discussed and built. Finally,the control system was designed and experiments were carried out. Experimental results show that WALKMAN-I is able to climb on the vertical wall surface along a straight line or a curved path,and has the ability of crossing orthogonal planes and obstacles. The maximum rotation angle reaches 90°,the maximum velocity reaches 5 mm/s,and the rotation angle and the moving velocity of WALKMAN-I can be easily controlled.展开更多
Flexible transfer line(FTL)is now widely used in ma ny manufacturing domains to realize efficiently,high quantity and economic prod uction.These manufacturing domains include automobile,tractor,internal-combu stion en...Flexible transfer line(FTL)is now widely used in ma ny manufacturing domains to realize efficiently,high quantity and economic prod uction.These manufacturing domains include automobile,tractor,internal-combu stion engine,and so on.In today’s competitive business environment,it is vit ally important for machine tool manufacturers to design flexible transfer line m ore effectively and efficiently according to a wider variety of customer demand s.This paper proposes an approach to a bidding-based flexible transfer line sc hematic design system.By analyzing manual FTL design process,the architecture o f flexible transfer line schematic design system(FTLSDS)is established.The syst em consists:of four processes:part feature modeling,process planning,FTL fac i lity layout and FTL evaluation. For FTL schematic design.a five-level proces s planning strategy named hierarchical process planning method is proposed.This method includes selection of manufacturing feature machining operation;part se t-up planning,feature sequencing,operation sequencing and process plan genera ting.The major decision relies on setup planning.According to the proceeding o f the hierarchical process planning,the structure of reasoning is proposed base d on blackboard.Under this paradigm,a cooperative effort between a hybrid coll ection of knowledge sources is possible.Total reasoning task can be divided int o some subtasks,and recursive-reasoning system is formed.It is convenient for process planning with step-by-step solution.Meanwhile,the blackboard is use d as the global data exchange area during all reasoning process.By using modula r technology,special purpose machine tools can be designed more efficiently and rapidly.The framework of machine modular design system to support machine requ irement design for FTL is established.By synthesizing the FTL evaluation criter ia.five evaluation criteria of flexible transfer 1ine schematic design are take n into account.An exampie is supplied to demonstrate and verify the validity an d feasibility of flexible transfer line schematic design approach.展开更多
In supply chain management,an important research direction is to coordinate the supply chain through introducing flexible contracts.A supply chain contract is flexible if it can satisfy two conditions at the same time...In supply chain management,an important research direction is to coordinate the supply chain through introducing flexible contracts.A supply chain contract is flexible if it can satisfy two conditions at the same time:the supply chain is coordinated,and the total profit of the supply chain can be arbitrarily divided between the supply chain members.This paper puts out two contracts,a flexible return contract and a flexible wholesale price discount contract.In contrast to many of literature,the supply chain contracts with an endogenous wholesale price is specifically considered,and a detailed sensitivity analysis of the contract parameters is given.The paper also discusses the application of the contract in vendor-managed inventory(VMI)mode.The results show that the supply chain's performance is improved after introducing above contracts.All the findings are illustrated by numerical examples.展开更多
文摘Quantum dot(QD)-based fluorescent inks offer high potential due to their tunable emission and high quantum yield,but their practical application suffers from poor environmental stability,aggregation,and challenges in scalable flexible fabrication.In this study,a high-stability fluorescent ink was developed by incorporating QDs into a polydimethylsiloxane(PDMS)colloidal matrix.High-performance patterned films were then obtained via systematic optimization of screen-printing parameters,with film quality governed by substrate type(131μm PDMS),QD concentration(1.5 mg/mL),and screen mesh count(420 mesh).The optimized films exhibit outstanding environmental and photostability,retaining 75.6% of their fluorescence intensity after immersion in deionized water and 63.8% in 75%ethanol at 25℃ for 100 minutes.Under UV irradiation(365 nm,9 W,100 min),fluorescence intensity decreases by less than 20%.Utilizing their daylight transparency and UV-excitable luminescence,various patterns including QR codes and Code 93 standard barcodes were fabricated via screen printing with high pattern fidelity and machine readability.This study presents a scalable and reliable strategy for the fabrication of flexible,high-stability fluorescent films,supporting their integration into next-generation optoelectronic devices,advanced displays,and secure anti-counterfeiting.
基金supported by the National Natural Science Foundation of China (Grant Nos. 22275092, 52102107)supported by the Postgraduate Research & Practice Innovation Program of Jiangsu Province (Grant No. KYCX24_0709)+2 种基金supported by the China Scholarship Council program (Grant No. 202406840160),which provided the opportunity for international collaborationsupported by the Fundamental Research Funds for the Central Universities (Grant No. 30923010920)the State Key Laboratory of Transient Chemical Effects and Control (Grant No. 6142602230201)
文摘This work pioneers a transient electrical explosive flexible igniter based on a polyurethane-copper composite,achieving unprecedented microsecond-scale plasma initiation(0.75μs threshold at 30 V)through key innovations.A dual-V geometric design concentrating current density.Electroless copper plating(ECP)enabling 80μm conductive layers with flexibility.Capacitive discharge optimization for tunable energy delivery(0.058–1.088 mJ).The flexible architecture demonstrates remarkable mechanical-electrical decoupling-maintaining functionality under 140 kg compressive loads(250%improvement over rigid igniters)and 90°torsional deformation while delivering consistent plasma jets(3–5 mm height,180–580μs duration).Based on the analysis of the multi-physics field simulation re-sults,multiphase energy conversion occurs during the electrical explosion process.The initial Joule heating reaches the melting point of copper,and then an electrical explosion plasma is generated.Voltage-dependent studies identify 50 V as the critical threshold for performance leap,where peak current increases 46.56%and plasma duration extends 214.29%versus 30 V operation.These advances establish a new class of high-speed ignition systems combiningμs-response,140 kg shock resistance,and conformal deployment capabilities for next-generation munitions and micro-propulsion applications.This work extends the application of flexible electronics to the field of transient ignition.
基金supported in part by the National Natural Sci-ence Foundation of China(No.62403486)in part by the Young Elite Scientists Sponsorship Program by CAST.
文摘To address efficient operation scheduling of shipboard helicopter groups under multi-mission demands and limited deck space,a novel Flexible Operation Mode(FOM)was proposed.Mission grouping,deck operation processes,and mission time were flexibilized to construct a mission planning method.From the perspective of the deck operation lifecycle,the scheduling problem was modeled as a six-stage mixed-integer program.A bi-level optimization framework was introduced,prioritizing maximization of mission time window satisfaction and secondarily minimizing mean deck operation time.Spatial evolution during the transportation phase was managed via an offline trajectory library that converted high-dimensional constraints into low-dimensional parameter mappings,significantly reducing real-time solution complexity.A Leader-Follower Particle Swarm Optimization(LFPSO)algorithm was developed,featuring a three-stage stochastic priority encoding and a mission-chain-driven launch-re-covery decoupling strategy to reduce decision coupling.A hierarchical population structure enhanced co-evolution of global search and local refinement.The case simulation results show that the proposed model and algorithm can effectively solve the deck operation scheduling problem in complex mission scenarios,and are significantly superior to the Continuous Operation Mode(COM)and the Fixed-process FOM(FFOM)in key performance indicators such as mission time window satisfaction,average deck operation time,and average mission flight time.Its effectiveness in enhancing system scheduling capability and performance stability has been verified.This research provides systematic support for the flexible construction and intelligent decision-making of ship aviation operation systems.
基金Projects(62105262,62205141,62405134)supported by the National Natural Science Foundation of ChinaProject(23KJA430010)supported by the Natural Science Funds of the Education Committee of Jiangsu Province,China+5 种基金Project(BK20230342)supported by the Natural Science Foundation of Jiangsu Province for Youth,ChinaProject(2024M753737)supported by the Postdoctoral Science Foundation,ChinaProject(RCBS20231211090610014)supported by the Shenzhen Science and Technology Program,ChinaProject(K2025-08)supported by the Open Research Fund from the State Key Laboratory of Molecular Engineering of Polymers,ChinaProject(KYCX24_1649)supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province,ChinaProject(23KJB150014)supported by the Natural Science Foundation of Jiangsu Higher Education Institutions,China。
文摘Stretchable polymer semiconductor film(SPSF)is the core to fabricate the flexible optoelectronic devices,due to its excellent strain-tolerance capacity.Softness of polymer chain realized via introducing flexible segment at the backbone and side-substituents is the effective strategy to obtain SPSFs,but easily causing the relatively instable film morphology and weak energy dissipation ability.Herein,we proposed a convenient side-chain cross-linked strategy to prepare the stretchable SPSF with an outstanding morphological stability for flexible polymer light-emitting diodes(PLED).Styrene group is introduced as ended cross-linking unit into the side chain of fluorene to prepare the intrinsically stretchable alter-copolymers semiconductors poly(9,9-diphenyl-4-((6-(4-vinylphenoxy)hexyl)oxy)-9 H-fluorene)-alt(1,8-bis(4-phenoxy)octane)(PCm-alt-C8).Interestingly,PCm-alt-C8 cross-linked film easily obtained via thermal treatment at 180℃,had stable morphology,excellent solvent resistance and deep-blue emission simultaneously.Compared to the controlled PEt-alt-C8,PCm-alt-C8 cross-linked films also present an excellent strain-tolerance capacity with larger crack initiation strain rates and the elongation at break(both enhanced by about 90%).More important,stretchable PCm-alt-C8 cross-linked films showed a stable electroluminescent and electrical property with large stretching degree(>30%)and hundreds of cycles of cycling stretch deformations,suggesting their excellent strain tolerance capacity.Therefore,side-chain cross-linking is a universal strategy for the preparation of high-performance SPSF in flexible optoelectronics.
基金financial support from projects funded by the National Natural Science Foundation of China(52172038,22179017)the National Key Research and Development Program of China(2022YFB4101600,2022YFB4101601)。
文摘For rechargeable aqueous zinc-ion batteries(ZIBs),the design of nanocomposites comprised of electrochemically active materials and carbon materials with novel structures has great prom-ise in addressing the issue of electrical conductivity and structural stability in the electrode materials during electrochemical cycling.We report the production of a novel flexible electrode material,by anchoring MnO_(2) nanosheets on a B,N co-doped carbon nanotube ar-ray(BNCNTs)grown on carbon cloth(BNCNTs@MnO_(2)),which was fabricated by in-situ pyrolysis and hydrothermal growth.The generated BNCNTs were strongly bonded to the surface of the car-bon fibers in the carbon cloth which provides both excellent elec-tron transport and ion diffusion,and improves the stability and dur-ability of the cathode.Importantly,the BNCNTs offer more active sites for the hydrothermal growth of MnO_(2),ensuring a uniform dis-tribution.Electrochemical tests show that BNCNTs@MnO_(2) delivers a high specific capacity of 310.7 mAh g^(−1) at 0.1 A g^(−1),along with excellent rate capability and outstanding cycling stability,with a 79.7% capacity retention after 8000 cycles at 3 A g^(−1).
文摘Electrospinning technology has emerged as a promising method for fabricating flexible lithium-ion batter-ies(FLIBs)due to its ability to create materials with desir-able properties for energy storage applications.FLIBs,which are foldable and have high energy densities,are be-coming increasingly important as power sources for wear-able devices,flexible electronics,and mobile energy applica-tions.Carbon materials,especially carbon nanofibers,are pivotal in improving the performance of FLIBs by increas-ing electrical conductivity,chemical stability,and surface area,as well as reducing costs.These materials also play a significant role in establishing conducting networks and im-proving structural integrity,which are essential for extend-ing the cycle life and enhancing the safety of the batteries.This review considers the role of electrospinning in the fabrication of critical FLIB components,with a particular emphasis on the integration of carbon materials.It explores strategies to optimize FLIB performance by fine-tuning the electrospinning para-meters,such as electric field strength,spinning rate,solution concentration,and carbonization process.Precise control over fiber properties is crucial for enhancing battery reliability and stability during folding and bending.It also highlights the latest research findings in carbon-based electrode materials,high-performance electrolytes,and separator structures,discussing the practical challenges and opportunities these materials present.It underscores the significant impact of carbon materials on the evolution of FLIBs and their potential to shape future energy storage technologies.
基金funded by the"14th Five-Year Plan"Civil Aerospace Pre-research Project of China(Grant No.D010301).
文摘Reusable and flexible capturing of space debris is highly required in future aerospace technologies.A tendon-actuated flexible robotic arm is therefore proposed for capturing floating targets in this paper.Firstly,an accurate dynamic model of the flexible robotic arm is established by using the absolute nodal coordinate formulation(ANCF)in the framework of the arbitrary Lagrangian-Eulerian(ALE)description and the natural coordinate formulation(NCF).The contact and self-contact dynamics of the flexible robotic arm when bending and grasping an object are considered via a fast contact detection approach.Then,the dynamic simulations of the flexible robotic arm for capturing floating targets are carried out to study the influence of the position,size,and mass of the target object on the grasping performance.Finally,a principle prototype of the tendon-actuated flexible robotic arm is manufactured to validate the dynamic model.The corresponding grasping experiments for objects of various shapes are also conducted to illustrate the excellent performance of the flexible robotic arm.
基金Project(2025A1515011803)supported by the Guangdong Basic and Applied Basic Research Foundation,ChinaProject(2023JC01020)supported by the Jiangmen Basic and Theoretical Science Research Plan,China。
文摘The increase in aerodynamic drag brings high energy consumption,which is a critical issue in the development of high-speed trains.Inspired by the excellent hydrodynamic characteristics of fish movement in nature,a two-dimensional numerical simulation method based on spring-smoothing model and adaptive mesh technology was utilized to explore the effects of different fishtail structures and two flexible motion modes(Eel mode and Lunate-tail mode)on the wake of high-speed trains,and to assess their potential for aerodynamic drag reduction.Results indicate that the biomimetic fishtail successfully suppresses the alternating shedding of vortices in the wake,and induces the aerodynamic drag fluctuation period to align with the fishtail oscillation period.The fishtail length,oscillation mode,and frequency have a significant impact on the wake flow and aerodynamic drag of the train.Among these,a 1850 mm Eel fishtail with parameters ofλ=1 and T=8 s achieves the optimal drag reduction effect,with drag reduction rates of 39.12%and 26.00%for the tail car and the entire train,respectively.These findings provide a theoretical basis for the design of new low-resistance railway trains,promoting the sustainable development of rail transit towards goals of high-speed and energy-efficient.
基金supported by the National Natural Science Foundation of China(Grant No.52274177)Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJZD-K202401501)+1 种基金Chongqing Graduate Student Research Innovation Program(Grant No.CYS240800)The Science and Technology Innovation Project for Graduate Students of Chongqing University of Science and Technology(Grant No.YKJCX2420702).
文摘Urban growth has promoted the use of underground spaces,where explosion accidents can be catastrophic.In this study,we investigated the effect of placing flexible construction in front of rigid obstacles on methane explosion protection by using an experimental platform and adjusting the blockage rate and spacing of the obstacles.It aims to reduce the risk of gas explosions in urban underground spaces.The results of the study show that the flame propagation peak speed and peak overpressure are reduced with the decrease in the blocking rate of the flexible obstacle when the blocking rate of the flexible obstacle is less than or equal to the blocking rate of the rigid obstacle,with the decrease in the spacing,the better the protection effect of the methane explosion.When the blockage rate of the flexible obstacle is greater than the blockage rate of the rigid obstacle and spacing is less than the height of the flexible obstacle,rigid and flexible obstacles are connected as a whole,increasing the strength of the explosion.This study can provide a theoretical basis and scientific guidance for optimizing rigid and flexible object hybrid layouts and methane explosion protection technology in urban underground spaces.
基金National Natural Science Foundation of China-NSAF(Grant No.U2330202)the National Natural Science Foundation of China(Grant Nos.52175162 and 51805086)+1 种基金Fujian Provincial Technological Innovation Key Research and Industrialization Projects(Grant Nos.2023XQ005 and 2024XQ010)The National Independent Innovation Demonstration Platform Project of Fujian Province(2024QZFX07)。
文摘Flexible microporous metal rubber(FMP-MR)is widely used in national defense applications,yet its mechanical behavior under high-speed impact conditions remains insufficiently explored.In this study,dynamic and static experiments were conducted to systematically investigate the mechanical response of metal-wrapped microporous materials under impact loading that spanned 10~6 orders of magnitude.By combining a high-precision numerical model with a spatial contact point search algorithm,the spatio–temporal contact characteristics of the complex network structure in FMP-MR were systematically analyzed.Furthermore,the mapping mechanism from turn topology and mesoscopic friction behavior to macroscopic mechanical properties was comprehensively explored.The results showed that compared with quasi-static loading,FMP-MR under high-speed impact exhibited higher energy absorption efficiency due to high-strain-rate inertia effect.Therefore,the peak stress increased by 141%,and the maximum energy dissipation increased by 300%.Consequently,the theory of dynamic friction locking effect was innovatively proposed.The theory explains that the close synergistic effect of sliding friction and plastic dissipation promoted by the stable interturn-locked embedded structure is the essential reason for the excellent dynamic mechanical properties of FMP-MR under dynamic loading conditions.Briefly,based on the in-depth investigation of the mechanical response and energy dissipation mechanism of FMP-MR under impact loads,this study provides a solid theoretical basis for further expanding the application range of FMP-MR and optimizing its performance.
文摘目的探讨Supreme喉罩和Flexible喉罩不同通气罩内压对气道漏气压的影响。方法择期全麻乳腺手术患者,根据插入喉罩种类不同分为Supreme组(35例)和Flexible组(33例)。常规静脉麻醉诱导后由同一麻醉科医师插入Supreme或Flexible喉罩,确认位置良好,调整通气罩压力。分别记录通气罩压力为10、20、30、40、50 cm H2O(1 cm H2O=0.098 k Pa)时,两种喉罩的气道漏气压值。结果 Supreme组通气罩内压力20、30、40、50 cm H2O时,所对应的气道漏气压差异无统计学意义(P>0.05),但均显著高于10 cm H2O时气道漏气压(P<0.05);Flexible组通气罩内压力为30、40、50 cm H2O时,所对应的气道漏气压差异无统计学意义(P>0.05),但高于10、20 cm H2O时气道漏气压(P<0.05)。Supreme组患者的整体平均气道漏气压(25.40±5.52)cm H2O明显高于Flexible组的(20.67±3.06)cm H2O(P<0.05)。结论 Supreme喉罩的平均气道漏气压高于Flexible喉罩,达到最大平均气道漏气压时,Supreme喉罩所需的通气罩内压(20 cm H2O)低于Flexible喉罩(30 cm H2O)。
基金Projects(2014QNB18,2015XKMS022)supported by the Fundamental Research Funds for the Central Universities of ChinaProjects(51475456,51575511)supported by the National Natural Science Foundation of China+1 种基金Project supported by the Priority Academic Programme Development of Jiangsu Higher Education InstitutionsProject supported by the Visiting Scholar Foundation of China Scholarship Council
文摘The dynamics of spatial parallel manipulator with rigid and flexible links is explored. Firstly, a spatial beam element model for finite element analysis is established. Then, the differential equation of motion of beam element is derived based on finite element method. The kinematic constraints of parallel manipulator with rigid and flexible links are obtained by analyzing the motive parameters of moving platform and the relationships of movements of kinematic chains, and the overall kinetic equation of the parallel mechanism with rigid and flexible links is derived by assembling the differential equations of motion of components. On the basis of abovementioned analyses, the dynamic mechanical analysis of the spatial parallel manipulator with rigid and flexible links is conducted. After obtaining the method for force analysis and expressions for the calculation of dynamic stress of flexible components, the dynamic analysis and simulation of spatial parallel manipulator with rigid and flexible links is performed. The result shows that because of the elastic deformation of flexible components in the parallel mechanism with rigid and flexible links, the force on each component in the mechanism fluctuates sharply, and the change of normal stress at the root of drive components is also remarkable. This study provides references for further studies on the dynamic characteristics of parallel mechanisms with rigid and flexible links and for the optimization of the design of the mechanism.
基金supported by the National Natural Science Foundation of China(9101601861273092+3 种基金61203012)the Foundation for Key Program of Ministry of Education of China(311012)the Key Program for Basic Research of Tianjin(11JCZDJC25100)the Key Program of Tianjin Natural Science(12JCZDJC30300)
文摘The focus of this paper is on control design and simulation for the longitudinal model of a flexible air-breathing hypersonic vehicle（FAHV）.The model of interest includes flexibility effects and intricate couplings between the engine dynamics and flight dynamics.To overcome the analytical intractability of this model,a nominal control-oriented model is constructed for the purpose of feedback control design in the first place.Secondly,the multi-input multi-output（MIMO） quasi-continuous high-order sliding mode（HOSM） controller is proposed to track step changes in velocity and altitude,which is based on full state feedback.The simulation results are presented to verify the effectiveness of the proposed control strategy.
基金Projects(51605051,51975068)supported by the National Natural Science Foundation of China。
文摘Planet gear systems(PGSs)are key components of transmission mechanisms.Structural and material characteristics of gearbox and shaft can affect the support stiffness and vibrations of PGSs.The ring gear flexibility should affect the vibrations of PGSs too.However,most previous work did not completely consider the effects of the ring gear flexibility on the vibrations of PGSs and flexible supports of ring and sun gears.Thus,this paper presents a flexible-rigid coupling multi-body dynamic(FMBD)model for a PGS with the flexible supports and ring gear flexibility.A finite element model of ring gear is established to formulate the ring gear flexibility.The influences of clearance and damping of planet bearings on the vibrations of PGS are considered.The effects of flexible supports and ring gear flexibility on the vibrations of PGS under different moment and speed conditions are studied.The statistical parameters and peak frequencies of PGS from the proposed FMBD and previous rigid multi-body dynamic(RMBD)models are compared.The results denote that the flexible support has a great effect on the vibrations of PGS.This paper can provide some guidance for the support structure design and vibration control for PGSs.
基金supported by the National Natural Science Foundation of China(61473152)the China Scholarship Council and the Educational Innovation Project for Graduate Students of Jiangsu Province(KYLX15 0399)
文摘The issue of attitude maneuver of a flexible spacecraft is investigated with single gimbaled control moment gyroscopes （SGCMGs） as an actuator. To solve the inertia uncertainty of the system, an adaptive attitude control algorithm is designed by applying a radial basis function （RBF） neural network. An improved steering law for SGCMGs is proposed to achieve the optimal out- put torque. It enables the SGCMGs not only to avoid singularity, but also to output more precise torque. In addition, global, uniform, ultimate bounded stability of the attitude control system is proved via the Lyapunov technique. Simulation results demonstrate the effectiveness of the new steering law and the algorithm of attitude maneuver of the flexible spacecraft.
基金Project (50575206) supported by the National Natural Science Foundation of ChinaProject (BX102716) supported by Xinmiao Program of Zhejiang Province, China
文摘A new kind of flexible pneumatic wall-climbing robot,named WALKMAN-I,was proposed. WALKMAN-I is basically composed of a flexible pneumatic actuator (FPA),a flexible pneumatic spherical joint and six suction cups. It has many characteristics of low-cost,lightweight,simple structure and good flexibility. Its operating principle was introduced. Then three basic locomotion modes,which are linear motion,curvilinear motion and crossing the orthogonal planes,were presented. The safety conditions of WALKMAN-I were discussed and built. Finally,the control system was designed and experiments were carried out. Experimental results show that WALKMAN-I is able to climb on the vertical wall surface along a straight line or a curved path,and has the ability of crossing orthogonal planes and obstacles. The maximum rotation angle reaches 90°,the maximum velocity reaches 5 mm/s,and the rotation angle and the moving velocity of WALKMAN-I can be easily controlled.
文摘Flexible transfer line(FTL)is now widely used in ma ny manufacturing domains to realize efficiently,high quantity and economic prod uction.These manufacturing domains include automobile,tractor,internal-combu stion engine,and so on.In today’s competitive business environment,it is vit ally important for machine tool manufacturers to design flexible transfer line m ore effectively and efficiently according to a wider variety of customer demand s.This paper proposes an approach to a bidding-based flexible transfer line sc hematic design system.By analyzing manual FTL design process,the architecture o f flexible transfer line schematic design system(FTLSDS)is established.The syst em consists:of four processes:part feature modeling,process planning,FTL fac i lity layout and FTL evaluation. For FTL schematic design.a five-level proces s planning strategy named hierarchical process planning method is proposed.This method includes selection of manufacturing feature machining operation;part se t-up planning,feature sequencing,operation sequencing and process plan genera ting.The major decision relies on setup planning.According to the proceeding o f the hierarchical process planning,the structure of reasoning is proposed base d on blackboard.Under this paradigm,a cooperative effort between a hybrid coll ection of knowledge sources is possible.Total reasoning task can be divided int o some subtasks,and recursive-reasoning system is formed.It is convenient for process planning with step-by-step solution.Meanwhile,the blackboard is use d as the global data exchange area during all reasoning process.By using modula r technology,special purpose machine tools can be designed more efficiently and rapidly.The framework of machine modular design system to support machine requ irement design for FTL is established.By synthesizing the FTL evaluation criter ia.five evaluation criteria of flexible transfer 1ine schematic design are take n into account.An exampie is supplied to demonstrate and verify the validity an d feasibility of flexible transfer line schematic design approach.
基金supported by the Science and Technology Project of Zhejiang Province(2009C11026,2009C35007)
文摘In supply chain management,an important research direction is to coordinate the supply chain through introducing flexible contracts.A supply chain contract is flexible if it can satisfy two conditions at the same time:the supply chain is coordinated,and the total profit of the supply chain can be arbitrarily divided between the supply chain members.This paper puts out two contracts,a flexible return contract and a flexible wholesale price discount contract.In contrast to many of literature,the supply chain contracts with an endogenous wholesale price is specifically considered,and a detailed sensitivity analysis of the contract parameters is given.The paper also discusses the application of the contract in vendor-managed inventory(VMI)mode.The results show that the supply chain's performance is improved after introducing above contracts.All the findings are illustrated by numerical examples.
