This paper proposes a zer o current and zero voltage switching (ZCZVS) PWM Boost full bridge (FB) conve rter. With series inductors, the leading switches can realize zero current swit ching (ZCS) in a wide load ra...This paper proposes a zer o current and zero voltage switching (ZCZVS) PWM Boost full bridge (FB) conve rter. With series inductors, the leading switches can realize zero current swit ching (ZCS) in a wide load range using the energy of the output capacitor. Ma king use of parasitic capacitors of the lagging switches and parallel auxiliary i nductance with the primary winding of the transformer, the lagging switches can realize zero voltage switching (ZVS) under any load. Compared with the ZCS PWM Boost FB converter, the new converter has no current duty cycle loss. Operat ional principle and parameter design are analyzed. Experimental results verify the effectiveness of the proposed converter.展开更多
A soft switching three-transistor push-pull(TTPP)converter is proposed in this paper. The 3rd transistor is inserted in the primary side of a traditional push-pull converter. Two primitive transistors can achieve zero...A soft switching three-transistor push-pull(TTPP)converter is proposed in this paper. The 3rd transistor is inserted in the primary side of a traditional push-pull converter. Two primitive transistors can achieve zero-voltage-switching (ZVS) easily under a wide load range, the 3rd transistor can also realize zero-voltage-switching assisted by leakage inductance. The rated voltage of the 3rd transistor is half of that of the main transistors. The operation theory is explained in detail. The soft-switching realization conditions are derived. An 800 W with 83.3 kHz switching frequency prototype has been built. The experimental result is provided to verify the analysis.展开更多
The zero-voltage quasi-resonant boost switching DC-DC converter has been inves-tigated by using the time averaging equivalent circuit approach of periodically switching linearnetworks.The DC steady state and AC small ...The zero-voltage quasi-resonant boost switching DC-DC converter has been inves-tigated by using the time averaging equivalent circuit approach of periodically switching linearnetworks.The DC steady state and AC small signal characteristics of the converter are also given.展开更多
In comparison with several zero-voltage transition （ZVT） inverter topologies, a double-PWM converter is presented using a simple ZVT topology. The rectifier and inverter of this double-PWM share a set of commutation...In comparison with several zero-voltage transition （ZVT） inverter topologies, a double-PWM converter is presented using a simple ZVT topology. The rectifier and inverter of this double-PWM share a set of commutation circuit which can provide soft-switching for the power devices and the diodes. The commutation circuit consists of 1 auxiliary device, 6 resonant inductors, and 12 diodes. Its topology is simpler than the conventional auxiliary resonant converter, leading to low loss and easy control. The control strategy and resonant working modes are analyzed. Experimental results show good performance of the system.展开更多
This paper presents a new ZVT （zero-voltage transition） single-stage ac-to-dc converter using PWM （pulse width modulation） and HF （high frequency） transformer isolation with capacitive output filter. In this con...This paper presents a new ZVT （zero-voltage transition） single-stage ac-to-dc converter using PWM （pulse width modulation） and HF （high frequency） transformer isolation with capacitive output filter. In this converter a front-end power factor corrected boost stage integrates with a cascaded dc-to-dc bridge HF converter. The front-end boost converter operates in discontinuous current mode and ensures natural power factor correction with very simple control. The auxiliary circuit of this topology deals with very small power and is placed out of the main power path. As a result, the auxiliary circuit components have smaller power rating as opposed to main converter components. Also, output rectifier voltage is clamped to output voltage due to capacitive output filter. Identification and analyses of different operating modes of this converter are presented. Based on these analyses design example of a 50 kHz, 48 V, 1 kW ac-to-dc converter is presented. PSPICE simulation results of the designed converter are presented and explained to verify the performance of this converter.展开更多
Memristors have a synapse-like two-terminal structure and electrical properties,which are widely used in the construc-tion of artificial synapses.However,compared to inorganic materials,organic materials are rarely us...Memristors have a synapse-like two-terminal structure and electrical properties,which are widely used in the construc-tion of artificial synapses.However,compared to inorganic materials,organic materials are rarely used for artificial spiking synapses due to their relatively poor memrisitve performance.Here,for the first time,we present an organic memristor based on an electropolymerized dopamine-based memristive layer.This polydopamine-based memristor demonstrates the improve-ments in key performance,including a low threshold voltage of 0.3 V,a thin thickness of 16 nm,and a high parasitic capaci-tance of about 1μF·mm^(-2).By leveraging these properties in combination with its stable threshold switching behavior,we con-struct a capacitor-free and low-power artificial spiking neuron capable of outputting the oscillation voltage,whose spiking fre-quency increases with the increase of current stimulation analogous to a biological neuron.The experimental results indicate that our artificial spiking neuron holds potential for applications in neuromorphic computing and systems.展开更多
Switched Reluctance Motors(SRMs),outfitted with rugged construction,good speed range,high torque density,and rare earth-free nature that outweigh induction motors(IM)and permanent magnet synchronous motor(PMSM),afford...Switched Reluctance Motors(SRMs),outfitted with rugged construction,good speed range,high torque density,and rare earth-free nature that outweigh induction motors(IM)and permanent magnet synchronous motor(PMSM),afford a broad range of applications in the domain of electric vehicles(EVs).Standard copper magnetic wire and low-carbon steel laminations are used to construct SRMs,which give them high efficiency in the range of 85-95%.Despite SRM's desirable features over traditional motor-speed drives,high torque ripples and radial distortions constrain their deployment in EVs.Precise rotor position is imperative for effective management of the speed and torque of SRMs.This paper provides an illustrative compendium on review of the torque-speed control and ripple mitigation techniques using design enhancements and control methods for SRM drives for EV applications.The various schemes were evaluated on their performance metricsoperational speed range,control complexity,practical realization,need for pre-stored parameters(look-up tables of current,inductance and torque profiles)and motor controller memory requirements.The findings provide valuable insights into balancing the gains and trade-offs associated with EV applications.Furthermore,they pinpoint opportunities for enhancement by analyzing the cost and technical aspects of different SRM controllers.展开更多
Uneven power distribution,transient voltage,and frequency deviations are observed in the photovoltaic storage hybrid inverter during the switching between grid-connected and island modes.In response to these issues,th...Uneven power distribution,transient voltage,and frequency deviations are observed in the photovoltaic storage hybrid inverter during the switching between grid-connected and island modes.In response to these issues,this paper proposes a grid-connected/island switching control strategy for photovoltaic storage hybrid inverters based on the modified chimpanzee optimization algorithm.The proposed strategy incorporates coupling compensation and power differentiation elements based on the traditional droop control.Then,it combines the angular frequency and voltage amplitude adjustments provided by the phase-locked loop-free pre-synchronization control strategy.Precise pre-synchronization is achieved by regulating the virtual current to zero and aligning the photovoltaic storage hybrid inverter with the grid voltage.Additionally,two novel operators,learning and emotional behaviors are introduced to enhance the optimization precision of the chimpanzee algorithm.These operators ensure high-precision and high-reliability optimization of the droop control parameters for photovoltaic storage hybrid inverters.A Simulink model was constructed for simulation analysis,which validated the optimized control strategy’s ability to evenly distribute power under load transients.This strategy effectively mitigated transient voltage and current surges during mode transitions.Consequently,seamless and efficient switching between gridconnected and island modes was achieved for the photovoltaic storage hybrid inverter.The enhanced energy utilization efficiency,in turn,offers robust technical support for grid stability.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
We demonstrated a new type of MAX phase material,chromium titanium aluminum carbide(Cr_(2)TiAlC_(2)) polymer film,to generate a passively Q-switched erbium-doped fiber laser(EDFL).The film thickness was measured to be...We demonstrated a new type of MAX phase material,chromium titanium aluminum carbide(Cr_(2)TiAlC_(2)) polymer film,to generate a passively Q-switched erbium-doped fiber laser(EDFL).The film thickness was measured to be around 45 μm,which was fabricated using the embedding method with polyvinyl alcohol(PVA) polymer as hoster.The saturable absorber(SA) film demonstrates a dual-wavelength passively Q-switched EDFL which operates at 1 531 nm and 1 560.19 nm,respectively.The Q-switching pulse duration could be varied from 2.46 μs to 770 ns,while the repetition rate varied from 92.76 kHz to 106.6 kHz with an increasing input pumping range from 154 mW to 300 mW.The maximum output power and pulse energy of 15.05 mW and 141.18 nJ were obtained at the maximum input power of 300 mW,respectively.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
The phenomena of thermal runaway and accidental deformation due to external stresses in lithium batteries or film capacitors consti-tute their primary failure mechanisms.Therefore,monitoring and early warning of overh...The phenomena of thermal runaway and accidental deformation due to external stresses in lithium batteries or film capacitors consti-tute their primary failure mechanisms.Therefore,monitoring and early warning of overheating or localized strain are of great value for the safe use of lithium batteries or film capacitors;however,this function usually requires a system of multiple complex sensors.The realization of the above multiple hazards using a single sensor for monitoring and alarm functions has not been reported.Here,we exploit the thermally induced conductivity and modulus change during solid-liquid conversion of low melting point polyalloys to modulate the electronic relaxation polariza-tion and interfacial polarization in the composites for dielectric switching,and the reduction of alloy particle spacing during bending/compres-sive strain can be used to generate switchable tunneling effects for insulator-conductor transition.By synergizing dielectric switching and insula-tor-conductor transition,the final flexible thermoplastic polyurethane elastomer/low-melting-point polyalloy composite film achieves the func-tional integration of multi-level overheating warning and small deformation monitoring.展开更多
Background : SOX6 has been shown to play a crucial role in the development of the cardiovascular system. However, its potential role in hypertension and vascular function remains unclear. Methods : In vascular smooth ...Background : SOX6 has been shown to play a crucial role in the development of the cardiovascular system. However, its potential role in hypertension and vascular function remains unclear. Methods : In vascular smooth muscle cells(VSMCs), we employed gain-and loss-offunction approaches combined with RNA sequencing, autophagy flux assessment, and phenotype characterization. Additionally, we established a mouse model with Sox6 overexpression via adeno-associated virus 2(AAV2) to validate the findings in vivo. Results : We validated the increased expression of SOX6 in hypertension both in vitro and in vivo. Genetic silencing of Sox6 in VSMCs attenuated the phenotypic switching induced by angiotensin Ⅱ. Conversely, in vivo overexpression of Sox6 led to a significant elevation in blood pressure and promoted vascular remodeling. Mechanistically, SOX6 was shown to regulate phenotypic switching via an autophagydependent pathway. Specifically, Sox6 overexpression augmented VSMC autophagy and facilitated phenotypic switching, whereas Sox6 knockdown yielded opposite outcomes. Modulation of autophagy using 3-MA or RAPA could effectively counteract the effect mediated by SOX6. Conclusions : Our findings revealed that SOX6 regulates VSMC plasticity and elevates blood pressure by activating autophagy. Therefore, SOX6 inhibition potentially represents a novel strategy for treating hypertension and vascular remodeling.展开更多
To enable distributed PV to adapt to variations in power grid strength and achieve stable grid connection while enhancing operational flexibility,it is essential to configure grid-connected inverters with an integrate...To enable distributed PV to adapt to variations in power grid strength and achieve stable grid connection while enhancing operational flexibility,it is essential to configure grid-connected inverters with an integrated grid-following control mode,allowing smooth switching between GFL and GFM modes.First,impedance models of GFL and GFM PV energy storage VSG systems were established,and grid stability was analyzed.Second,an online impedance identification method based on voltage fluctuation data screening was proposed to enhance the accuracy of impedance identification.Additionally,a PV energy storage GFM/GFL VSG smooth switching method based on current inner loop compensation was introduced to achieve stable grid-connected operation of distributed photovoltaics under changes in strong and weak power grids.Finally,a grid stability analysis was conducted on the multi-machine parallel PV ESS,and a simulation model of a multi-machine parallel PV ESS based on current inner loop compensation was established for testing.Results showed that,compared to using a single GFM or single GFL control for the PV VSG system,the smooth switching method of multi-machine parallel PV ESS effectively suppresses system resonance under variations in power grid strength,enabling adaptive and stable grid-connected operations of distributed PV.展开更多
This paper presents an entire fixed-time disturbance observer-based global terminal switching sliding mode control of robot manipulators,which has inner and external uncertainties.The entire fixed-time disturbance obs...This paper presents an entire fixed-time disturbance observer-based global terminal switching sliding mode control of robot manipulators,which has inner and external uncertainties.The entire fixed-time disturbance observer-based global terminal switching sliding mode control has the global finite-time reaching characteristic,the property that system convergence time can be prescribed,and the global robustness to uncertainties,with the entire fixed-time disturbance observer that accurately estimates uncertainties after a fixed time,despite the initial state.The joints of the control system can arrive at the prescribed joint angular position at the predefined joint angular speed at the prescribed time.展开更多
A CMOS compatible RRAM device with TaN/Ta/TaOx/Ta N structure was proposed for nonvolatile memory applications.Excellent resistive switching characteristics,including low operation voltages(<1 V),low operation curr...A CMOS compatible RRAM device with TaN/Ta/TaOx/Ta N structure was proposed for nonvolatile memory applications.Excellent resistive switching characteristics,including low operation voltages(<1 V),low operation current(<100μA),good programming/erasing endurance(>10^(6) cycles),satisfactory uniformity,and reliable data retention,have been demonstrated.Furthermore,all of the elements in the fabricated Ta N/Ta/Ta Ox/Ta N devices are highly compatible with modern CMOS manufacturing process,showing promising application in the next generation of nonvolatile memory.展开更多
This article investigates the time-varying output group formation tracking control(GFTC)problem for heterogeneous multi-agent systems(HMASs)under switching topologies.The objective is to design a distributed control s...This article investigates the time-varying output group formation tracking control(GFTC)problem for heterogeneous multi-agent systems(HMASs)under switching topologies.The objective is to design a distributed control strategy that enables the outputs of the followers to form the desired sub-formations and track the outputs of the leader in each subgroup.Firstly,novel distributed observers are developed to estimate the states of the leaders under switching topologies.Then,GFTC protocols are designed based on the proposed observers.It is shown that with the distributed protocol,the GFTC problem for HMASs under switching topologies is solved if the average dwell time associated with the switching topologies is larger than a fixed threshold.Finally,an example is provided to illustrate the effectiveness of the proposed control strategy.展开更多
文摘This paper proposes a zer o current and zero voltage switching (ZCZVS) PWM Boost full bridge (FB) conve rter. With series inductors, the leading switches can realize zero current swit ching (ZCS) in a wide load range using the energy of the output capacitor. Ma king use of parasitic capacitors of the lagging switches and parallel auxiliary i nductance with the primary winding of the transformer, the lagging switches can realize zero voltage switching (ZVS) under any load. Compared with the ZCS PWM Boost FB converter, the new converter has no current duty cycle loss. Operat ional principle and parameter design are analyzed. Experimental results verify the effectiveness of the proposed converter.
文摘A soft switching three-transistor push-pull(TTPP)converter is proposed in this paper. The 3rd transistor is inserted in the primary side of a traditional push-pull converter. Two primitive transistors can achieve zero-voltage-switching (ZVS) easily under a wide load range, the 3rd transistor can also realize zero-voltage-switching assisted by leakage inductance. The rated voltage of the 3rd transistor is half of that of the main transistors. The operation theory is explained in detail. The soft-switching realization conditions are derived. An 800 W with 83.3 kHz switching frequency prototype has been built. The experimental result is provided to verify the analysis.
文摘The zero-voltage quasi-resonant boost switching DC-DC converter has been inves-tigated by using the time averaging equivalent circuit approach of periodically switching linearnetworks.The DC steady state and AC small signal characteristics of the converter are also given.
基金Project supported by the Shanghai Post Doctoral Scientific Research Project (Grant No.05R214122)the Shanghai Leading Academic Discipline Project (Grant No.T0103)
文摘In comparison with several zero-voltage transition （ZVT） inverter topologies, a double-PWM converter is presented using a simple ZVT topology. The rectifier and inverter of this double-PWM share a set of commutation circuit which can provide soft-switching for the power devices and the diodes. The commutation circuit consists of 1 auxiliary device, 6 resonant inductors, and 12 diodes. Its topology is simpler than the conventional auxiliary resonant converter, leading to low loss and easy control. The control strategy and resonant working modes are analyzed. Experimental results show good performance of the system.
文摘This paper presents a new ZVT （zero-voltage transition） single-stage ac-to-dc converter using PWM （pulse width modulation） and HF （high frequency） transformer isolation with capacitive output filter. In this converter a front-end power factor corrected boost stage integrates with a cascaded dc-to-dc bridge HF converter. The front-end boost converter operates in discontinuous current mode and ensures natural power factor correction with very simple control. The auxiliary circuit of this topology deals with very small power and is placed out of the main power path. As a result, the auxiliary circuit components have smaller power rating as opposed to main converter components. Also, output rectifier voltage is clamped to output voltage due to capacitive output filter. Identification and analyses of different operating modes of this converter are presented. Based on these analyses design example of a 50 kHz, 48 V, 1 kW ac-to-dc converter is presented. PSPICE simulation results of the designed converter are presented and explained to verify the performance of this converter.
基金support from the Beijing Natural Science Foundation-Xiaomi Innovation Joint Fund(No.L233009)National Natural Science Foundation of China(NSFC Nos.62422409,62174152,and 62374159)from the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2020115).
文摘Memristors have a synapse-like two-terminal structure and electrical properties,which are widely used in the construc-tion of artificial synapses.However,compared to inorganic materials,organic materials are rarely used for artificial spiking synapses due to their relatively poor memrisitve performance.Here,for the first time,we present an organic memristor based on an electropolymerized dopamine-based memristive layer.This polydopamine-based memristor demonstrates the improve-ments in key performance,including a low threshold voltage of 0.3 V,a thin thickness of 16 nm,and a high parasitic capaci-tance of about 1μF·mm^(-2).By leveraging these properties in combination with its stable threshold switching behavior,we con-struct a capacitor-free and low-power artificial spiking neuron capable of outputting the oscillation voltage,whose spiking fre-quency increases with the increase of current stimulation analogous to a biological neuron.The experimental results indicate that our artificial spiking neuron holds potential for applications in neuromorphic computing and systems.
基金supported in part by the Universitat Politècnica de València under grant PAID-10-21supported through AMRITA Seed Grant(Proposal ID:ASG2022188)。
文摘Switched Reluctance Motors(SRMs),outfitted with rugged construction,good speed range,high torque density,and rare earth-free nature that outweigh induction motors(IM)and permanent magnet synchronous motor(PMSM),afford a broad range of applications in the domain of electric vehicles(EVs).Standard copper magnetic wire and low-carbon steel laminations are used to construct SRMs,which give them high efficiency in the range of 85-95%.Despite SRM's desirable features over traditional motor-speed drives,high torque ripples and radial distortions constrain their deployment in EVs.Precise rotor position is imperative for effective management of the speed and torque of SRMs.This paper provides an illustrative compendium on review of the torque-speed control and ripple mitigation techniques using design enhancements and control methods for SRM drives for EV applications.The various schemes were evaluated on their performance metricsoperational speed range,control complexity,practical realization,need for pre-stored parameters(look-up tables of current,inductance and torque profiles)and motor controller memory requirements.The findings provide valuable insights into balancing the gains and trade-offs associated with EV applications.Furthermore,they pinpoint opportunities for enhancement by analyzing the cost and technical aspects of different SRM controllers.
基金received funding from the Postgraduate Research&Practice Innovation Program of Jiangsu Province(SJCX23_1633)2023 University Student Innovation and Entrepreneurship Training Program(202311463009Z)+1 种基金Changzhou Science and Technology Support Project(CE20235045)Open Project of Jiangsu Key Laboratory of Power Transmission&Distribution Equipment Technology(2021JSSPD12).
文摘Uneven power distribution,transient voltage,and frequency deviations are observed in the photovoltaic storage hybrid inverter during the switching between grid-connected and island modes.In response to these issues,this paper proposes a grid-connected/island switching control strategy for photovoltaic storage hybrid inverters based on the modified chimpanzee optimization algorithm.The proposed strategy incorporates coupling compensation and power differentiation elements based on the traditional droop control.Then,it combines the angular frequency and voltage amplitude adjustments provided by the phase-locked loop-free pre-synchronization control strategy.Precise pre-synchronization is achieved by regulating the virtual current to zero and aligning the photovoltaic storage hybrid inverter with the grid voltage.Additionally,two novel operators,learning and emotional behaviors are introduced to enhance the optimization precision of the chimpanzee algorithm.These operators ensure high-precision and high-reliability optimization of the droop control parameters for photovoltaic storage hybrid inverters.A Simulink model was constructed for simulation analysis,which validated the optimized control strategy’s ability to evenly distribute power under load transients.This strategy effectively mitigated transient voltage and current surges during mode transitions.Consequently,seamless and efficient switching between gridconnected and island modes was achieved for the photovoltaic storage hybrid inverter.The enhanced energy utilization efficiency,in turn,offers robust technical support for grid stability.
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.
文摘We demonstrated a new type of MAX phase material,chromium titanium aluminum carbide(Cr_(2)TiAlC_(2)) polymer film,to generate a passively Q-switched erbium-doped fiber laser(EDFL).The film thickness was measured to be around 45 μm,which was fabricated using the embedding method with polyvinyl alcohol(PVA) polymer as hoster.The saturable absorber(SA) film demonstrates a dual-wavelength passively Q-switched EDFL which operates at 1 531 nm and 1 560.19 nm,respectively.The Q-switching pulse duration could be varied from 2.46 μs to 770 ns,while the repetition rate varied from 92.76 kHz to 106.6 kHz with an increasing input pumping range from 154 mW to 300 mW.The maximum output power and pulse energy of 15.05 mW and 141.18 nJ were obtained at the maximum input power of 300 mW,respectively.
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financially supported by the National Natural Science Foundation of China (No.51503158)Key R&D Program of Hubei Province (No.2023BAB104)Open Project Program of High-Tech Organic Fibers Key Laboratory of Sichuan Province(No.PLN2024-08)
文摘The phenomena of thermal runaway and accidental deformation due to external stresses in lithium batteries or film capacitors consti-tute their primary failure mechanisms.Therefore,monitoring and early warning of overheating or localized strain are of great value for the safe use of lithium batteries or film capacitors;however,this function usually requires a system of multiple complex sensors.The realization of the above multiple hazards using a single sensor for monitoring and alarm functions has not been reported.Here,we exploit the thermally induced conductivity and modulus change during solid-liquid conversion of low melting point polyalloys to modulate the electronic relaxation polariza-tion and interfacial polarization in the composites for dielectric switching,and the reduction of alloy particle spacing during bending/compres-sive strain can be used to generate switchable tunneling effects for insulator-conductor transition.By synergizing dielectric switching and insula-tor-conductor transition,the final flexible thermoplastic polyurethane elastomer/low-melting-point polyalloy composite film achieves the func-tional integration of multi-level overheating warning and small deformation monitoring.
基金Beijing Nova Program,Grant/Award Number:20230484842National Natural Science Foundation of China,Grant/Award Number:82470461。
文摘Background : SOX6 has been shown to play a crucial role in the development of the cardiovascular system. However, its potential role in hypertension and vascular function remains unclear. Methods : In vascular smooth muscle cells(VSMCs), we employed gain-and loss-offunction approaches combined with RNA sequencing, autophagy flux assessment, and phenotype characterization. Additionally, we established a mouse model with Sox6 overexpression via adeno-associated virus 2(AAV2) to validate the findings in vivo. Results : We validated the increased expression of SOX6 in hypertension both in vitro and in vivo. Genetic silencing of Sox6 in VSMCs attenuated the phenotypic switching induced by angiotensin Ⅱ. Conversely, in vivo overexpression of Sox6 led to a significant elevation in blood pressure and promoted vascular remodeling. Mechanistically, SOX6 was shown to regulate phenotypic switching via an autophagydependent pathway. Specifically, Sox6 overexpression augmented VSMC autophagy and facilitated phenotypic switching, whereas Sox6 knockdown yielded opposite outcomes. Modulation of autophagy using 3-MA or RAPA could effectively counteract the effect mediated by SOX6. Conclusions : Our findings revealed that SOX6 regulates VSMC plasticity and elevates blood pressure by activating autophagy. Therefore, SOX6 inhibition potentially represents a novel strategy for treating hypertension and vascular remodeling.
基金supported by National Key Research and Development Technology Project program(SQ2022YFB2400136).
文摘To enable distributed PV to adapt to variations in power grid strength and achieve stable grid connection while enhancing operational flexibility,it is essential to configure grid-connected inverters with an integrated grid-following control mode,allowing smooth switching between GFL and GFM modes.First,impedance models of GFL and GFM PV energy storage VSG systems were established,and grid stability was analyzed.Second,an online impedance identification method based on voltage fluctuation data screening was proposed to enhance the accuracy of impedance identification.Additionally,a PV energy storage GFM/GFL VSG smooth switching method based on current inner loop compensation was introduced to achieve stable grid-connected operation of distributed photovoltaics under changes in strong and weak power grids.Finally,a grid stability analysis was conducted on the multi-machine parallel PV ESS,and a simulation model of a multi-machine parallel PV ESS based on current inner loop compensation was established for testing.Results showed that,compared to using a single GFM or single GFL control for the PV VSG system,the smooth switching method of multi-machine parallel PV ESS effectively suppresses system resonance under variations in power grid strength,enabling adaptive and stable grid-connected operations of distributed PV.
文摘This paper presents an entire fixed-time disturbance observer-based global terminal switching sliding mode control of robot manipulators,which has inner and external uncertainties.The entire fixed-time disturbance observer-based global terminal switching sliding mode control has the global finite-time reaching characteristic,the property that system convergence time can be prescribed,and the global robustness to uncertainties,with the entire fixed-time disturbance observer that accurately estimates uncertainties after a fixed time,despite the initial state.The joints of the control system can arrive at the prescribed joint angular position at the predefined joint angular speed at the prescribed time.
基金Project supported by the Key Research and Development Program of Gansu Province-Industrial Project(Grant No.25YFGA005)。
文摘A CMOS compatible RRAM device with TaN/Ta/TaOx/Ta N structure was proposed for nonvolatile memory applications.Excellent resistive switching characteristics,including low operation voltages(<1 V),low operation current(<100μA),good programming/erasing endurance(>10^(6) cycles),satisfactory uniformity,and reliable data retention,have been demonstrated.Furthermore,all of the elements in the fabricated Ta N/Ta/Ta Ox/Ta N devices are highly compatible with modern CMOS manufacturing process,showing promising application in the next generation of nonvolatile memory.
文摘This article investigates the time-varying output group formation tracking control(GFTC)problem for heterogeneous multi-agent systems(HMASs)under switching topologies.The objective is to design a distributed control strategy that enables the outputs of the followers to form the desired sub-formations and track the outputs of the leader in each subgroup.Firstly,novel distributed observers are developed to estimate the states of the leaders under switching topologies.Then,GFTC protocols are designed based on the proposed observers.It is shown that with the distributed protocol,the GFTC problem for HMASs under switching topologies is solved if the average dwell time associated with the switching topologies is larger than a fixed threshold.Finally,an example is provided to illustrate the effectiveness of the proposed control strategy.
