In this paper,a comprehensive evaluation on the silicon/silicon carbide(Si/SiC)hybrid switch is performed through experimental tests in terms of both electrical performance and robustness under extreme stresses.Based ...In this paper,a comprehensive evaluation on the silicon/silicon carbide(Si/SiC)hybrid switch is performed through experimental tests in terms of both electrical performance and robustness under extreme stresses.Based on the optional turn-on and turn-off delay times under the efficiency control mode obtained from the double-pulse test(DPT),both nondestructive and destructive single-pulse avalanche tests are conducted on the Si/SiC hybrid switch as well as on the two discrete device branches inside the hybrid switch.In addition,the avalanche voltage,critical avalanche energy,and peak avalanche current,which intrinsically characterize the unclamped-inductive-switching(UIS)avalanche characteristics,are carefully examined.In this way,the physical factors dominating the UIS characteristics of the hybrid switch,thus limiting its single-pulse avalanche withstand capability,are specifically and comprehensively identified;the underlying physical mechanisms are analyzed and revealed in depth,and how the gate control sequence affects the UIS characteristics of the hybrid switch is extensively investigated.We additionally carry out short-circuit(SC)tests under the fault-under-load(FUL)condition and perform a parallel in-depth analysis to experimentally determine which branch dominates the SC withstand capability of the hybrid switch.Our experimental study indicates that,for both SC robustness and single-pulse avalanche capability,the limiting factor is a single device branch among the two parallel discrete devices,and the UIS behavior is sensitive to the variation of the gate turn-off delay time Toff_delay.The study conducted in this paper not only provides deep academic insights into the electrical performance and reliability of the Si/SiC hybrid switch,but also offers fundamental theoretical principles and technical evidence to support its more efficient and long-term reliable applications of the hybrid switch in the industrial fields.展开更多
In this paper,we present a broadband,high-extinction-ratio,nonvolatile 2×2 Mach-Zehnder interfer⁃ometer(MZI)optical switch based on the phase change material Sb_(2)Se_(3).The insertion loss(IL)is 0.84 dB and the ...In this paper,we present a broadband,high-extinction-ratio,nonvolatile 2×2 Mach-Zehnder interfer⁃ometer(MZI)optical switch based on the phase change material Sb_(2)Se_(3).The insertion loss(IL)is 0.84 dB and the extinction ratio(ER)reaches 28.8 dB at the wavelength of 1550 nm.The 3 dB bandwidth is greater than 150 nm.Within the 3 dB bandwidth,the ER is greater than 20.3 dB and 16.3 dB at bar and cross states,respectively.The power consumption for crystallization and amorphization of Sb_(2)Se_(3) is 105.86 nJ and 49 nJ,respectively.The switch holds significant promise for optical interconnects and optical computing applications.展开更多
A stochastic predator-prey system with Markov switching is explored.We have developed a new chasing technique to efficiently solve the Fokker-Planck-Kolmogorov and backward Kolmogorov equations.Dynamic balance and rel...A stochastic predator-prey system with Markov switching is explored.We have developed a new chasing technique to efficiently solve the Fokker-Planck-Kolmogorov and backward Kolmogorov equations.Dynamic balance and reliability of the switching system are evaluated via stationary probability density function and first-passage failure theory,taking into account factors such as switching frequencies,noise intensities,and initial conditions.Results reveal that Markov switching leads to stochastic P-bifurcation,enhancing dynamic balance and reducing white-noise-induced oscillations.But frequent switching can heighten initial value dependence,harming reliability.Further,the influence of the subsystem on the switching system is not proportional to its action probabilities.Monte Carlo simulations validate the findings,offering an in-depth exploration of these dynamics.展开更多
Field-effect nanofluidic transistors(FENTs),biomimicking the structure and functionality of neuron,act as biological transistors with the ability to gate switching responses to external stimuli.The switching ratio has...Field-effect nanofluidic transistors(FENTs),biomimicking the structure and functionality of neuron,act as biological transistors with the ability to gate switching responses to external stimuli.The switching ratio has been verified to evaluate the performance of FENTs,but until recently,the response time,another crucial indicator,has been ignored.Employing finite-element method,we investigated the relationship among gate charge,switching ratio and response time by divisionally manipulating gate charge,including entrance surface and the surface of confinement space,for ion transport to optimize switching capability.The dual-split gate charge on FENTs exhibits synergistic effect on switching response.Based on the two regional gate charge on FENTs,multivalence ions in lower concentration,high aspect ratio and single channel show higher switching ratio but longer response time compared to monovalent ions.The findings highlight the necessity of balancing these two signals in FENTs and offer insights for optimizing their design and expanding applications to dual-signal-detection iontronics.展开更多
Soft machines harness material-level physical intelligence to perform adaptive tasks,enabling advancements in biomedical and human-machine interaction fields.Soft switches are the basic building blocks to achieve inte...Soft machines harness material-level physical intelligence to perform adaptive tasks,enabling advancements in biomedical and human-machine interaction fields.Soft switches are the basic building blocks to achieve intelligent functions like autonomous decisions and mechanical computation.However,current soft switches suffer from complex fabrication processes,limited performance,and a lack of multimodal control,which hinder their practical application and the realization of machine intelligence.Herein,by harnessing the unique self-pinch and self-healing effects of the gallium-based liquid metals(LMs),we describe a soft high-performance electric switch composed of an LM line encapsulated within an elastomer.Applying pressure to deform the LM switch can increase local current density,leading to the electromagnetic self-pinch effect for switching off.After releasing pressure,the LM can spontaneously heal with the elastic recovery of the elastomer for switching on.This LM switch shows comprehensive advantages,including a compact design(0.5 mm×1.5 mm×10 mm),good stretchability(100%),high on/off ratio(~10^(9)),rapid response time(<100 ms),and excellent durability(>12000 cycles).Moreover,the LM switches enable multiple control modes,including magnetic and optical stimulation,through the integration of responsive materials.We demonstrate various LM switch-enabled functional soft machines,such as an interactive flexible gripper,a self-oscillating soft crawler,and wearable logic gates.This work will open new avenues for the application of LM in intelligent soft machines and advanced wearable electronics.展开更多
Coherent perfect absorption(CPA)and coherent perfect transmission(CPT)are two extreme states arising from the manipulation of optical fields.Generally,CPA and CPT occur under different input-field phases.Therefore,we ...Coherent perfect absorption(CPA)and coherent perfect transmission(CPT)are two extreme states arising from the manipulation of optical fields.Generally,CPA and CPT occur under different input-field phases.Therefore,we propose a scheme to realize an all-optical switch based on phase-dependent CPA–CPT conversion.In our proposal,the CPT state and the CPA state are treated as the on state and the off state,respectively.Consequently,the efficiency of this all-optical switch can reach the maximum value of 1.With the introduction of an incoherent pump field,the CPA state can be achieved under a weaker input probe field or can be converted into a CPT state.The results show that the optical switch can operate with weaker fields and can be further optimized by the application of an incoherent field.展开更多
High Speed on/off Valve(HSV)is an essential component in Aerospace Digital Hydraulic Systems(ADHS),which impose stringent requirements on the dynamic performance and reliability of HSV due to the extreme application e...High Speed on/off Valve(HSV)is an essential component in Aerospace Digital Hydraulic Systems(ADHS),which impose stringent requirements on the dynamic performance and reliability of HSV due to the extreme application environments.However,the faster dynamic leads to increased impact between the spool and valve body,causing severe vibration and wear,which creates a conflict between rapid dynamic and high reliability.To address this problem,a Pre-Excitation Soft Switching Control(PESSC)with both pre-excitation and reverse deceleration functionalities is proposed.The initial current is optimized through pre-excitation to accelerate the opening time,while the application of reverse voltage hastens the decline of electromagnetic force,thereby reducing the spool velocity.The PESSC simultaneously achieves both faster dynamic performance and smaller impact velocity.Moreover,the optimal deceleration voltage parameters are obtained through multi-objective optimization.Experimental results demonstrate that the optimized PESSC shortens the opening time from 2.22 ms to 1.65 ms,reduces the impact velocity by 58.3%,and lowers wear by 55.4%.These findings underline the huge potential of PESSC in enhancing the dynamic performance and reliability of HSVs,offering promising applications in aerospace.展开更多
This paper focuses on the leader-following positive consensus problems of heterogeneous switched multi-agent systems.First,a state-feedback controller with dynamic compensation is introduced to achieve positive consen...This paper focuses on the leader-following positive consensus problems of heterogeneous switched multi-agent systems.First,a state-feedback controller with dynamic compensation is introduced to achieve positive consensus under average dwell time switching.Then sufficient conditions are derived to guarantee the positive consensus.The gain matrices of the control protocol are described using a matrix decomposition approach and the corresponding computational complexity is reduced by resorting to linear programming and co-positive Lyapunov functions.Finally,two numerical examples are provided to illustrate the results obtained.展开更多
This paper is concerned with adaptive consensus tracking control of nonlinear multi-agent systems with actuator faults and unknown nonidentical control directions under double semi-Markovian switching topologies.Consi...This paper is concerned with adaptive consensus tracking control of nonlinear multi-agent systems with actuator faults and unknown nonidentical control directions under double semi-Markovian switching topologies.Considering the complex working environment and the stability differences in communication links between leaders and followers,a double semi-Markov process is first introduced to describe the random switching of communication topologies in the leader-follower structure.In order to address challenges from the unknown nonidentical control directions and partial loss of effectiveness actuator faults,a completely independent parameter is introduced into the Nussbaum function to overcome the inherent obstacle of mutual cancellation and avoid the rapid growth rate.Considering only the state information of agents is transmitted among the agents,an adaptive distributed fault-tolerant consensus tracking control is proposed based on the double semi-Markovian switching topologies using the designed Nussbaum function.Furthermore,the stability of the closed-loop nonlinear multi-agent systems is analyzed using contradiction argument and Lyapunov theorem,from which the asymptotic consensus tracking in mean square sense can be obtained.A numerical simulation example is provided to verify the effectiveness of the proposed algorithm.展开更多
The enhancement of perpendicular magnetic anisotropy(PMA)is critical for the continuous growth of magnetic memory density.Material systems that possess high interfacial PMA typically involve strong spin-orbit coupling...The enhancement of perpendicular magnetic anisotropy(PMA)is critical for the continuous growth of magnetic memory density.Material systems that possess high interfacial PMA typically involve strong spin-orbit coupling(SOC)or transition metal/oxide interfaces.In contrast,the role of 3d light metals in enhancing the interfacial PMA has been less investigated.This study demonstrated that the insertion of a few atomic Cr layers into Pt/Co/Pt/Ta heterostructures with Cr between the 1 atomic Pt layer and the 3 nm Ta overlayer enhanced the effective PMA energy(K_(eff))by a factor of 4.First-principles calculations revealed that the underlying mechanism originated from Cr-Pt d-orbital hybridization,leading to a corresponding orbital redistribution and significantly increasing the magnetic anisotropy energy.The progressive reduction in the spin-orbit torque(SOT)efficiency with increasing Cr thickness might stem from the enhanced orbital Rashba–Edelstein effect at the Pt/Cr interface.Furthermore,the wedging of a few atomic Cr layers caused the robust field-free SOT switching of perpendicular magnetization,which was due to the lateral PMA gradients enabled by the strong dependence of the PMA on the Cr thickness.The results provide a method for interfacial PMA enhancement by d-orbital hybridization of 3d–5d electrons and an alternative to field-free SOT switching towards low-power and high-density memory applications.展开更多
Dear Editor,In this letter,several novel controllability results for a class of linear switched and impulsive systems are established.Different from the developed controllability conditions in most existing literature...Dear Editor,In this letter,several novel controllability results for a class of linear switched and impulsive systems are established.Different from the developed controllability conditions in most existing literature,the important role of switched and impulsive time sequence is considered.Applying the relevant geometric theory of matrix,a necessary and sufficient criterion for the controllability is firstly developed to judge when the controllability of such systems is affected by switched and impulsive time sequence.Furthermore,we further obtain a sufficient controllability condition that can be used to verify the controllability of such systems regardless of the switched and impulsive time sequence.Finally,a numerical example is given to verify the obtained theoretical results.展开更多
Dear Editor,This letter studies finite-time stability (FTS) of impulsive and switched hybrid systems with delay-dependent impulses. Some conditions, based on Lyapunov method, are proposed for ensuring FTS and estimati...Dear Editor,This letter studies finite-time stability (FTS) of impulsive and switched hybrid systems with delay-dependent impulses. Some conditions, based on Lyapunov method, are proposed for ensuring FTS and estimating settling-time function (STF) of the hybrid systems.When switching dynamics are FTS and impulsive dynamics involve destabilizing delay-dependent impulses, the FTS is retained if the impulses occur infrequently.展开更多
Stimuli-responsive materials offer significant potential for high-security encryption,smart sensors,and optoelectronic switching due to their reversible state transitions triggered by external stimuli(temperature,ligh...Stimuli-responsive materials offer significant potential for high-security encryption,smart sensors,and optoelectronic switching due to their reversible state transitions triggered by external stimuli(temperature,light,or electric fields).Combining quasi-spherical molecular design with chiral engineering,we designed enantiomeric organic amine-borane adduct crystals exhibiting multi-channel switching behavior at room temperature.The strategic introduction of intramolecular hydrogen bonding and chirality in engineered R/S-HQNB crystals successfully enables room-temperature structural phase transitions.This transition is coupled with pronounced onoff switching in dielectric,SHG,and SHG-CD responses,demonstrating practical application potential through ambient-temperature operation,which is rarely documented in pure small molecule organic crystals.This advance establishes a pathway for functional organic materials design and enables chiral optical applications with integrated stimuli-responsive capabilities.展开更多
Dear Editor,This letter is concerned with the problem of time-varying formation tracking for heterogeneous multi-agent systems(MASs) under directed switching networks. For this purpose, our first step is to present so...Dear Editor,This letter is concerned with the problem of time-varying formation tracking for heterogeneous multi-agent systems(MASs) under directed switching networks. For this purpose, our first step is to present some sufficient conditions for the exponential stability of a particular category of switched systems.展开更多
Switched linear parameter varying(LPV)systems have,in recent years,inspired a great number of research endeavors owing to their excellent ability to approximate nonlinear systems and handle complex hybrid dynamics in ...Switched linear parameter varying(LPV)systems have,in recent years,inspired a great number of research endeavors owing to their excellent ability to approximate nonlinear systems and handle complex hybrid dynamics in system analysis and synthesis.Nevertheless,numerous difficulties and challenges are also encountered due to the reciprocal effects of switching signals and scheduling parameters in the analysis and synthesis of switched LPV systems.In this paper,the standard description and specific characteristics of switched LPV systems are first introduced.Then,the main methodologies are proposed in the literature to cope with stability and performance analysis,control synthesis,as well as fault diagnosis and fault-tolerant control issues,and the typical applications in various fields are surveyed.Finally,several key open problems and current research activities are also discussed to elucidate the potential research directions in the future.展开更多
Background:The use of antidepressants in the treatment of bipolar depression remains controversial due to concerns about their potential to induce mood polarity switches.This multinational observational study aims to ...Background:The use of antidepressants in the treatment of bipolar depression remains controversial due to concerns about their potential to induce mood polarity switches.This multinational observational study aims to examine the association between the use of antidepressants and the risk of hypomanic/manic switch among bipolar depressive patients.Methods:Four electronic health record databases(IQVIA Disease Analyzer Germany,IQVIA Disease Analyzer France,IQVIA US Hospital Charge Data Master,and Beijing Anding Hospital)and one administrative claims database(IQVIA US Open Claims)were analyzed,and the study period covered from January 2013 until December 2017.Treatment patterns of patients with bipolar depression were collected.The hazard ratio(HR)was calculated by comparing the incidence of hypomanic/manic switch in patients who received antidepressants(AD group)with that in those who did not receive any antidepressant(non-AD group)in 730 days after the date of the first diagnosis of bipolar depression.Results:The analysis included a total of 122,843 patients from the 5 databases;60.6% of them received antidepressants for bipolar depression.Across the 5 data sources,the mean age at index date ranged from 37.50(15.72)to 52.10(16.22)years.After controlling potential confounders by propensity score matching,the AD group’s manic switch risk was not significantly higher than the non-AD group’s(HR 1.04[95%CI,0.96 to 1.13];P=0.989).Additionally,no statistically significant difference was observed between patients prescribed antimanic drugs and those who were not(HR 0.69[95%CI,0.38 to 1.25];P=0.535).Conclusions:This study indicated that antidepressants were widely used in clinical settings for managing bipolar depression.The use of antidepressants was not associated with the risk of mania/hypomania switch when compared to non-antidepressants treatment.Therefore,antidepressants could be considered a treatment option for bipolar depression.展开更多
This study presents the design of an erbium-doped fiber laser(EDFL) featuring switchable wavelength intervals achieved through the implementation of cascaded and parallel Lyot filters. The proposed laser system utiliz...This study presents the design of an erbium-doped fiber laser(EDFL) featuring switchable wavelength intervals achieved through the implementation of cascaded and parallel Lyot filters. The proposed laser system utilizes a cascaded and parallel configuration of three Lyot filters, facilitated by a polarization beam splitter(PBS) for branch switching. The transmission properties of the filter are analyzed through theoretical modeling and experimental validation using the transmission matrix method. The experimental results are found to be consistent with the theoretical predictions, demonstrating the effectiveness of the proposed design. By adjusting the polarization controllers(PCs), the proposed laser can switch between wavelength spacings of 0.46 nm, 0.27 nm, and 0.76 nm, with a maximum optical signal-to-noise ratio(OSNR) of 38 d B. However, the stability of the laser with a 0.27 nm spacing is not high due to wavelength competition. Power fluctuation for 0.46 nm and 0.76 nm intervals is less than 0.93 d B and 0.78 d B in 1 h, with wavelength fluctuation less than 0.068 nm and 0.19 nm, respectively. This EDFL has the advantages of simple structure, great flexibility, and switchability, which can be applied to fiber optic sensing, wavelength division multiplexing(WDM) networks, and other fields that require a very flexible light source.展开更多
The problem of admissibility analysis and control synthesis of discrete-time switched linear singular （SLS） systems for arbitrary switching laws is solved. By using the switched Lyapunov function approach, some new ...The problem of admissibility analysis and control synthesis of discrete-time switched linear singular （SLS） systems for arbitrary switching laws is solved. By using the switched Lyapunov function approach, some new sufficient conditions under which the SLS system is admissible for arbitrary switching laws are derived in terms of linear matrix inequalities （LMIs）. Based on the admissibility results, control synthesis is then to design switched state feedback and static output feedback controllers, guaranteeing that the resulting closed-loop system is admissible. The presented results can be viewed as the extensions of previous works on switched Lyapunov function approach from the regular switched systems to singular switched cases. Examples are provided to demonstrate the reduced conservatism and effectiveness of the proposed conditions.展开更多
Maintaining mitochondrial homeostasis is critical for preserving chondrocyte physiological conditions and increasing resistance against osteoarthritis(OA).However,the underlying mechanisms governing mitochondrial self...Maintaining mitochondrial homeostasis is critical for preserving chondrocyte physiological conditions and increasing resistance against osteoarthritis(OA).However,the underlying mechanisms governing mitochondrial self-renewal and energy production remain elusive.In this study,we demonstrated mitochondrial damage and aberrant mitophagy in OA chondrocytes.Genetically overexpressing PTEN-induced putative kinase 1(PINK1)protects against cartilage degeneration by removing defective mitochondria.PINK1 knockout aggravated cartilage damage due to impaired mitophagy.SIRT3 directly deacetylated PINK1 to promote mitophagy and cartilage anabolism.Specifically,PINK1 phosphorylated PKM2 at the Ser127 site,preserving its active tetrameric form.This inhibited nuclear translocation and the interaction withβ-catenin,resulting in a metabolic shift and increased energy production.Finally,a double-knockout mouse model demonstrated the role of the SIRT3-PINK1-PKM2 axis in safeguarding the structural integrity of articular joints and improving motor functions.Overall,this study provides a novel insight into the regulation of mitochondrial renewal and metabolic switches in OA.展开更多
基金supported in part by the Anhui Provincial Natural Science Foundation Youth Project(Category C)under Grant No.2508085QE184the Opening Project of Key Laboratory of Power Electronics and Motion Control of Anhui Higher Education Institutions under Grant No.PEMC24004+1 种基金the Anhui University of Technology Young Teachers Research Fund under Grant No.QZ202412the Scientific Research Startup Fund for Introduced Talents of Anhui University of Technology under Grant No.QD202340.
文摘In this paper,a comprehensive evaluation on the silicon/silicon carbide(Si/SiC)hybrid switch is performed through experimental tests in terms of both electrical performance and robustness under extreme stresses.Based on the optional turn-on and turn-off delay times under the efficiency control mode obtained from the double-pulse test(DPT),both nondestructive and destructive single-pulse avalanche tests are conducted on the Si/SiC hybrid switch as well as on the two discrete device branches inside the hybrid switch.In addition,the avalanche voltage,critical avalanche energy,and peak avalanche current,which intrinsically characterize the unclamped-inductive-switching(UIS)avalanche characteristics,are carefully examined.In this way,the physical factors dominating the UIS characteristics of the hybrid switch,thus limiting its single-pulse avalanche withstand capability,are specifically and comprehensively identified;the underlying physical mechanisms are analyzed and revealed in depth,and how the gate control sequence affects the UIS characteristics of the hybrid switch is extensively investigated.We additionally carry out short-circuit(SC)tests under the fault-under-load(FUL)condition and perform a parallel in-depth analysis to experimentally determine which branch dominates the SC withstand capability of the hybrid switch.Our experimental study indicates that,for both SC robustness and single-pulse avalanche capability,the limiting factor is a single device branch among the two parallel discrete devices,and the UIS behavior is sensitive to the variation of the gate turn-off delay time Toff_delay.The study conducted in this paper not only provides deep academic insights into the electrical performance and reliability of the Si/SiC hybrid switch,but also offers fundamental theoretical principles and technical evidence to support its more efficient and long-term reliable applications of the hybrid switch in the industrial fields.
基金Supported by the National Natural Science Foundation of China(62204250)Autonomous deployment project of State Key Laboratory of Materials for Integrated Circuits(SKLJC-Z2024-A05).
文摘In this paper,we present a broadband,high-extinction-ratio,nonvolatile 2×2 Mach-Zehnder interfer⁃ometer(MZI)optical switch based on the phase change material Sb_(2)Se_(3).The insertion loss(IL)is 0.84 dB and the extinction ratio(ER)reaches 28.8 dB at the wavelength of 1550 nm.The 3 dB bandwidth is greater than 150 nm.Within the 3 dB bandwidth,the ER is greater than 20.3 dB and 16.3 dB at bar and cross states,respectively.The power consumption for crystallization and amorphization of Sb_(2)Se_(3) is 105.86 nJ and 49 nJ,respectively.The switch holds significant promise for optical interconnects and optical computing applications.
基金Project supported by the National Natural Science Foundation of China(Grant No.12472033)。
文摘A stochastic predator-prey system with Markov switching is explored.We have developed a new chasing technique to efficiently solve the Fokker-Planck-Kolmogorov and backward Kolmogorov equations.Dynamic balance and reliability of the switching system are evaluated via stationary probability density function and first-passage failure theory,taking into account factors such as switching frequencies,noise intensities,and initial conditions.Results reveal that Markov switching leads to stochastic P-bifurcation,enhancing dynamic balance and reducing white-noise-induced oscillations.But frequent switching can heighten initial value dependence,harming reliability.Further,the influence of the subsystem on the switching system is not proportional to its action probabilities.Monte Carlo simulations validate the findings,offering an in-depth exploration of these dynamics.
基金supported by the Natural Science Foundation of Guangdong Province,China (No.2025A1515011654)the National Natural Science Foundation of China (No.22090053)+3 种基金the Fundamental Research Funds for National Universities,China University of Geosciences (Wuhan)support from the program of China Scholarships Council (No.202406410155)Young Elite Scientists Sponsorship Program by CAST-Doctoral Student Special Plansupport from the S&T Special Program of Huzhou (No.2024GZ07)。
文摘Field-effect nanofluidic transistors(FENTs),biomimicking the structure and functionality of neuron,act as biological transistors with the ability to gate switching responses to external stimuli.The switching ratio has been verified to evaluate the performance of FENTs,but until recently,the response time,another crucial indicator,has been ignored.Employing finite-element method,we investigated the relationship among gate charge,switching ratio and response time by divisionally manipulating gate charge,including entrance surface and the surface of confinement space,for ion transport to optimize switching capability.The dual-split gate charge on FENTs exhibits synergistic effect on switching response.Based on the two regional gate charge on FENTs,multivalence ions in lower concentration,high aspect ratio and single channel show higher switching ratio but longer response time compared to monovalent ions.The findings highlight the necessity of balancing these two signals in FENTs and offer insights for optimizing their design and expanding applications to dual-signal-detection iontronics.
基金financial support from the Natural Science Foundation of Jiangsu Province(BK20220859)the Jiangsu Provincial Scientific Research Center of Applied Mathematics(BK20233002)+2 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX24_0473)the SEU Innovation Capability Enhancement Plan for Doctoral Students(CXJH_SEU 24144)supported by Open Research Fund of State Key Laboratory of Analytical Chemistry for Life Science,School of Chemistry and Chemical Engineering,Nanjing University。
文摘Soft machines harness material-level physical intelligence to perform adaptive tasks,enabling advancements in biomedical and human-machine interaction fields.Soft switches are the basic building blocks to achieve intelligent functions like autonomous decisions and mechanical computation.However,current soft switches suffer from complex fabrication processes,limited performance,and a lack of multimodal control,which hinder their practical application and the realization of machine intelligence.Herein,by harnessing the unique self-pinch and self-healing effects of the gallium-based liquid metals(LMs),we describe a soft high-performance electric switch composed of an LM line encapsulated within an elastomer.Applying pressure to deform the LM switch can increase local current density,leading to the electromagnetic self-pinch effect for switching off.After releasing pressure,the LM can spontaneously heal with the elastic recovery of the elastomer for switching on.This LM switch shows comprehensive advantages,including a compact design(0.5 mm×1.5 mm×10 mm),good stretchability(100%),high on/off ratio(~10^(9)),rapid response time(<100 ms),and excellent durability(>12000 cycles).Moreover,the LM switches enable multiple control modes,including magnetic and optical stimulation,through the integration of responsive materials.We demonstrate various LM switch-enabled functional soft machines,such as an interactive flexible gripper,a self-oscillating soft crawler,and wearable logic gates.This work will open new avenues for the application of LM in intelligent soft machines and advanced wearable electronics.
基金supported by the National Natural Science Foundation of China(Grants Nos.12304405,12275203,and 12075176)the Natural Science Foundation of Shaanxi Provincial Department of Education(Grant No.23JK0483)+2 种基金the Natural Science Basic Research Program of Shaanxi(Grant Nos.2024JC-YBMS-521 and 2024JC-YBMS-039)the 2022 Shaanxi University Youth Innovation Team Project(Grant No.K20220186)the College Students’Innovative Entrepreneurial Training Plan Program of Shaanxi(Grant No.S202410702178)。
文摘Coherent perfect absorption(CPA)and coherent perfect transmission(CPT)are two extreme states arising from the manipulation of optical fields.Generally,CPA and CPT occur under different input-field phases.Therefore,we propose a scheme to realize an all-optical switch based on phase-dependent CPA–CPT conversion.In our proposal,the CPT state and the CPA state are treated as the on state and the off state,respectively.Consequently,the efficiency of this all-optical switch can reach the maximum value of 1.With the introduction of an incoherent pump field,the CPA state can be achieved under a weaker input probe field or can be converted into a CPT state.The results show that the optical switch can operate with weaker fields and can be further optimized by the application of an incoherent field.
基金supported in part by the “Pioneer”and “Leading Goose”R&D Program of Zhejiang Province(Nos.2022C01132 and 2022C01122)the National Natural Science Foundation of China(No.52005441)+3 种基金the Young Elite Scientist Sponsorship Program by CAST(No.20222024QNRC001)the State Key Laboratory of Mechanical System and Vibration,China(No.MSV202316)the Fundamental Research Funds for the Provincial Universities of Zhejiang,China(RF-A2023007)the Research Project of ZJUT,China(No.GYY-ZH-2023075)。
文摘High Speed on/off Valve(HSV)is an essential component in Aerospace Digital Hydraulic Systems(ADHS),which impose stringent requirements on the dynamic performance and reliability of HSV due to the extreme application environments.However,the faster dynamic leads to increased impact between the spool and valve body,causing severe vibration and wear,which creates a conflict between rapid dynamic and high reliability.To address this problem,a Pre-Excitation Soft Switching Control(PESSC)with both pre-excitation and reverse deceleration functionalities is proposed.The initial current is optimized through pre-excitation to accelerate the opening time,while the application of reverse voltage hastens the decline of electromagnetic force,thereby reducing the spool velocity.The PESSC simultaneously achieves both faster dynamic performance and smaller impact velocity.Moreover,the optimal deceleration voltage parameters are obtained through multi-objective optimization.Experimental results demonstrate that the optimized PESSC shortens the opening time from 2.22 ms to 1.65 ms,reduces the impact velocity by 58.3%,and lowers wear by 55.4%.These findings underline the huge potential of PESSC in enhancing the dynamic performance and reliability of HSVs,offering promising applications in aerospace.
基金supported by the National Natural Science Foundation of China(62463007,62463005)the Natural Science Foundation of Hainan Province(625RC710,625MS047)+1 种基金the System Control and Information Processing Education Ministry Key Laboratory Open Funding,China(Scip20240119)the Science Research Funding of Hainan University,China(KYQD(ZR)22180,KYQD(ZR)23180).
文摘This paper focuses on the leader-following positive consensus problems of heterogeneous switched multi-agent systems.First,a state-feedback controller with dynamic compensation is introduced to achieve positive consensus under average dwell time switching.Then sufficient conditions are derived to guarantee the positive consensus.The gain matrices of the control protocol are described using a matrix decomposition approach and the corresponding computational complexity is reduced by resorting to linear programming and co-positive Lyapunov functions.Finally,two numerical examples are provided to illustrate the results obtained.
基金supported by the National Natural Science Foundation of China(62333011,62020106003)the Natural Science Foundation of Jiangsu Province of China(BK20222012)+1 种基金the Fundamental Research Funds for the Central Universities(NE2024005)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX24_0594)。
文摘This paper is concerned with adaptive consensus tracking control of nonlinear multi-agent systems with actuator faults and unknown nonidentical control directions under double semi-Markovian switching topologies.Considering the complex working environment and the stability differences in communication links between leaders and followers,a double semi-Markov process is first introduced to describe the random switching of communication topologies in the leader-follower structure.In order to address challenges from the unknown nonidentical control directions and partial loss of effectiveness actuator faults,a completely independent parameter is introduced into the Nussbaum function to overcome the inherent obstacle of mutual cancellation and avoid the rapid growth rate.Considering only the state information of agents is transmitted among the agents,an adaptive distributed fault-tolerant consensus tracking control is proposed based on the double semi-Markovian switching topologies using the designed Nussbaum function.Furthermore,the stability of the closed-loop nonlinear multi-agent systems is analyzed using contradiction argument and Lyapunov theorem,from which the asymptotic consensus tracking in mean square sense can be obtained.A numerical simulation example is provided to verify the effectiveness of the proposed algorithm.
基金supported by the “Pioneer” and “Leading Goose” R&D Program of Zhejiang Province (Grant No.2022C01053)the National Natural Science Foundation of China (Grant No.62293493)the Natural Science Foundation of Zhejiang Province,China (Grant No.LQ21A050001)。
文摘The enhancement of perpendicular magnetic anisotropy(PMA)is critical for the continuous growth of magnetic memory density.Material systems that possess high interfacial PMA typically involve strong spin-orbit coupling(SOC)or transition metal/oxide interfaces.In contrast,the role of 3d light metals in enhancing the interfacial PMA has been less investigated.This study demonstrated that the insertion of a few atomic Cr layers into Pt/Co/Pt/Ta heterostructures with Cr between the 1 atomic Pt layer and the 3 nm Ta overlayer enhanced the effective PMA energy(K_(eff))by a factor of 4.First-principles calculations revealed that the underlying mechanism originated from Cr-Pt d-orbital hybridization,leading to a corresponding orbital redistribution and significantly increasing the magnetic anisotropy energy.The progressive reduction in the spin-orbit torque(SOT)efficiency with increasing Cr thickness might stem from the enhanced orbital Rashba–Edelstein effect at the Pt/Cr interface.Furthermore,the wedging of a few atomic Cr layers caused the robust field-free SOT switching of perpendicular magnetization,which was due to the lateral PMA gradients enabled by the strong dependence of the PMA on the Cr thickness.The results provide a method for interfacial PMA enhancement by d-orbital hybridization of 3d–5d electrons and an alternative to field-free SOT switching towards low-power and high-density memory applications.
基金supported in part by the National Natural Science Foundation of China(62322311,62303162,62233007,62203157)the Technology Development Program of Henan Province(242102211052).
文摘Dear Editor,In this letter,several novel controllability results for a class of linear switched and impulsive systems are established.Different from the developed controllability conditions in most existing literature,the important role of switched and impulsive time sequence is considered.Applying the relevant geometric theory of matrix,a necessary and sufficient criterion for the controllability is firstly developed to judge when the controllability of such systems is affected by switched and impulsive time sequence.Furthermore,we further obtain a sufficient controllability condition that can be used to verify the controllability of such systems regardless of the switched and impulsive time sequence.Finally,a numerical example is given to verify the obtained theoretical results.
基金supported by the National Natural Science Foundation of China(61833005)
文摘Dear Editor,This letter studies finite-time stability (FTS) of impulsive and switched hybrid systems with delay-dependent impulses. Some conditions, based on Lyapunov method, are proposed for ensuring FTS and estimating settling-time function (STF) of the hybrid systems.When switching dynamics are FTS and impulsive dynamics involve destabilizing delay-dependent impulses, the FTS is retained if the impulses occur infrequently.
基金supported by the National Natural Science Foundation of China(22222502,22405114)the Research Team Program of Gannan Normal University.
文摘Stimuli-responsive materials offer significant potential for high-security encryption,smart sensors,and optoelectronic switching due to their reversible state transitions triggered by external stimuli(temperature,light,or electric fields).Combining quasi-spherical molecular design with chiral engineering,we designed enantiomeric organic amine-borane adduct crystals exhibiting multi-channel switching behavior at room temperature.The strategic introduction of intramolecular hydrogen bonding and chirality in engineered R/S-HQNB crystals successfully enables room-temperature structural phase transitions.This transition is coupled with pronounced onoff switching in dielectric,SHG,and SHG-CD responses,demonstrating practical application potential through ambient-temperature operation,which is rarely documented in pure small molecule organic crystals.This advance establishes a pathway for functional organic materials design and enables chiral optical applications with integrated stimuli-responsive capabilities.
基金supported in part by the National Natural Science Foundation of China(62273255,62350003,62088101)the Shanghai Science and Technology Cooperation Project(22510712000,21550760900)+1 种基金the Shanghai Municipal Science and Technology Major Project(2021SHZDZX0100)the Fundamental Research Funds for the Central Universities
文摘Dear Editor,This letter is concerned with the problem of time-varying formation tracking for heterogeneous multi-agent systems(MASs) under directed switching networks. For this purpose, our first step is to present some sufficient conditions for the exponential stability of a particular category of switched systems.
基金supported in part by the National Natural Science Foundation of China(62222310,61973131,62473379)the National Key Research and Develepment Program of China(2024YFB3310701)+1 种基金the Research Fund for the Taishan Scholar Project of Shandong Province of China,the Major Basic Research of Natural Science Foundation of Shandong Province(ZR2024ZD38,ZR2022ZD34)the Japan Society for the Promotion of Science(21K04129).
文摘Switched linear parameter varying(LPV)systems have,in recent years,inspired a great number of research endeavors owing to their excellent ability to approximate nonlinear systems and handle complex hybrid dynamics in system analysis and synthesis.Nevertheless,numerous difficulties and challenges are also encountered due to the reciprocal effects of switching signals and scheduling parameters in the analysis and synthesis of switched LPV systems.In this paper,the standard description and specific characteristics of switched LPV systems are first introduced.Then,the main methodologies are proposed in the literature to cope with stability and performance analysis,control synthesis,as well as fault diagnosis and fault-tolerant control issues,and the typical applications in various fields are surveyed.Finally,several key open problems and current research activities are also discussed to elucidate the potential research directions in the future.
基金partially supported by the Beijing Municipal Administration of Hospitals Incubating Program(PX20211903 and PX2019071)Capital’s Funds for Health Improvement and Research(2024-4-2129)+1 种基金the Beijing Municipal Science&Technology Commission(Z221100007422010)the Beijing High Level Public Health Professionals Training Plan(xuekegugan-01-12).
文摘Background:The use of antidepressants in the treatment of bipolar depression remains controversial due to concerns about their potential to induce mood polarity switches.This multinational observational study aims to examine the association between the use of antidepressants and the risk of hypomanic/manic switch among bipolar depressive patients.Methods:Four electronic health record databases(IQVIA Disease Analyzer Germany,IQVIA Disease Analyzer France,IQVIA US Hospital Charge Data Master,and Beijing Anding Hospital)and one administrative claims database(IQVIA US Open Claims)were analyzed,and the study period covered from January 2013 until December 2017.Treatment patterns of patients with bipolar depression were collected.The hazard ratio(HR)was calculated by comparing the incidence of hypomanic/manic switch in patients who received antidepressants(AD group)with that in those who did not receive any antidepressant(non-AD group)in 730 days after the date of the first diagnosis of bipolar depression.Results:The analysis included a total of 122,843 patients from the 5 databases;60.6% of them received antidepressants for bipolar depression.Across the 5 data sources,the mean age at index date ranged from 37.50(15.72)to 52.10(16.22)years.After controlling potential confounders by propensity score matching,the AD group’s manic switch risk was not significantly higher than the non-AD group’s(HR 1.04[95%CI,0.96 to 1.13];P=0.989).Additionally,no statistically significant difference was observed between patients prescribed antimanic drugs and those who were not(HR 0.69[95%CI,0.38 to 1.25];P=0.535).Conclusions:This study indicated that antidepressants were widely used in clinical settings for managing bipolar depression.The use of antidepressants was not associated with the risk of mania/hypomania switch when compared to non-antidepressants treatment.Therefore,antidepressants could be considered a treatment option for bipolar depression.
基金supported by the Primary Research and Development Plan of Zhejiang Province (No.2023C03014)the Key Research and Development Program of Zhejiang Province (No.2022C03037)。
文摘This study presents the design of an erbium-doped fiber laser(EDFL) featuring switchable wavelength intervals achieved through the implementation of cascaded and parallel Lyot filters. The proposed laser system utilizes a cascaded and parallel configuration of three Lyot filters, facilitated by a polarization beam splitter(PBS) for branch switching. The transmission properties of the filter are analyzed through theoretical modeling and experimental validation using the transmission matrix method. The experimental results are found to be consistent with the theoretical predictions, demonstrating the effectiveness of the proposed design. By adjusting the polarization controllers(PCs), the proposed laser can switch between wavelength spacings of 0.46 nm, 0.27 nm, and 0.76 nm, with a maximum optical signal-to-noise ratio(OSNR) of 38 d B. However, the stability of the laser with a 0.27 nm spacing is not high due to wavelength competition. Power fluctuation for 0.46 nm and 0.76 nm intervals is less than 0.93 d B and 0.78 d B in 1 h, with wavelength fluctuation less than 0.068 nm and 0.19 nm, respectively. This EDFL has the advantages of simple structure, great flexibility, and switchability, which can be applied to fiber optic sensing, wavelength division multiplexing(WDM) networks, and other fields that require a very flexible light source.
基金supported partly by the National Natural Science Foundation of China(6057400660835001)+1 种基金the Key Project of Chinese Ministry of Education(108060)the Jiangsu Planned Projects for Postdoctoral Research Funds(0802010c).
文摘The problem of admissibility analysis and control synthesis of discrete-time switched linear singular （SLS） systems for arbitrary switching laws is solved. By using the switched Lyapunov function approach, some new sufficient conditions under which the SLS system is admissible for arbitrary switching laws are derived in terms of linear matrix inequalities （LMIs）. Based on the admissibility results, control synthesis is then to design switched state feedback and static output feedback controllers, guaranteeing that the resulting closed-loop system is admissible. The presented results can be viewed as the extensions of previous works on switched Lyapunov function approach from the regular switched systems to singular switched cases. Examples are provided to demonstrate the reduced conservatism and effectiveness of the proposed conditions.
基金supported by grants from National Nature Science Foundation of China(82272494,82472452,82402864)National Key R&D Program of China(2022YFC2502902)+4 种基金Key Project of Jiangsu Health Commission(K2023079)Natural Science Foundation of Jiangsu Province(BK20240368)Basic Research Pilot Project Suzhou(SSD2024062),China Postdoctoral Science Foundation(2024M762313)Boxi Youth Natural Science Foundation(BXQN2023014)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Maintaining mitochondrial homeostasis is critical for preserving chondrocyte physiological conditions and increasing resistance against osteoarthritis(OA).However,the underlying mechanisms governing mitochondrial self-renewal and energy production remain elusive.In this study,we demonstrated mitochondrial damage and aberrant mitophagy in OA chondrocytes.Genetically overexpressing PTEN-induced putative kinase 1(PINK1)protects against cartilage degeneration by removing defective mitochondria.PINK1 knockout aggravated cartilage damage due to impaired mitophagy.SIRT3 directly deacetylated PINK1 to promote mitophagy and cartilage anabolism.Specifically,PINK1 phosphorylated PKM2 at the Ser127 site,preserving its active tetrameric form.This inhibited nuclear translocation and the interaction withβ-catenin,resulting in a metabolic shift and increased energy production.Finally,a double-knockout mouse model demonstrated the role of the SIRT3-PINK1-PKM2 axis in safeguarding the structural integrity of articular joints and improving motor functions.Overall,this study provides a novel insight into the regulation of mitochondrial renewal and metabolic switches in OA.
