This paper investigates the problem of cluster synchronization of master-slave complex net-works with time-varying delay via linear and adaptive feedback pinning controls.We need not non-delayed and delayed coupling m...This paper investigates the problem of cluster synchronization of master-slave complex net-works with time-varying delay via linear and adaptive feedback pinning controls.We need not non-delayed and delayed coupling matrices to be symmetric or irreducible.We have the advantages of using adaptive control method to reduce control gain and pinning control technology to reduce cost.By con-structing Lyapunov function,some sufficient synchronization criteria are established.Finally,numerical examples are employed to illustrate the effectiveness of the proposed approach.展开更多
This paper concerns with the master-slave exponential synchronization analysis for a class of general Lur'esystems with time delay.Different from the previous methods based on the differential inequality technique...This paper concerns with the master-slave exponential synchronization analysis for a class of general Lur'esystems with time delay.Different from the previous methods based on the differential inequality technique, a newapproach is proposed to derive some new exponential synchronization criteria.The restriction that the control widthhas to be larger than the time delay is removed.This leads to a larger application scope for our method.Moreover, notranscendental equation is involved in the obtained result, which reduces the computational burden.Two examples aregiven to validate the theoretical results.展开更多
This paper proposes an adaptive synchronization problem for the master and slave structure of linear systems with nonlinear perturbations and mixed time-varying delays comprising different discrete and distributed tim...This paper proposes an adaptive synchronization problem for the master and slave structure of linear systems with nonlinear perturbations and mixed time-varying delays comprising different discrete and distributed time delays. Using an appropriate Lyapunov-Krasovskii functional, some delay-dependent sufficient conditions and an adaptation law including the master-slave parame- ters are established for designing a delayed synchronization law in terms of linear matrix inequalities（LMIs）. The time-varying controller guarantees the H ∞ synchronization of the two coupled master and slave systems regardless of their initial states. Particularly, it is shown that the synchronization speed can be controlled by adjusting the updated gain of the synchronization signal. Two numerical examples are given to demonstrate the effectiveness of the method.展开更多
In this paper,a self-developed master-slave follow-up disc cutter is used to conduct rock-breaking tests on hard sandstone samples.Different working parameters were employed in the tests(e.g.cutting depth,cutting spee...In this paper,a self-developed master-slave follow-up disc cutter is used to conduct rock-breaking tests on hard sandstone samples.Different working parameters were employed in the tests(e.g.cutting depth,cutting speed,cutting angle,and rotational speed)in order to explore their influences on cutting performance.The results indicate that the thrust,torque,vibration velocity,and roughness all increased continuously with increase of the propulsion speed and cutting depth.At the same time,the specific energy consumption was found to decrease continuously.As the rotational speed was increased,the thrust increased at first and then decreased.In contrast,the torque and roughness continuously decreased,and the specific energy consumption and vibration speed continuously increased.When the cutting angle was increased,the thrust remained unchanged.However,the torque,specific energy consumption,and vibration speed all decreased continuously,and the roughness increased continuously.The temperature of the surface of the cutting tool was found to be relatively uniformly distributed during the rock-breaking process;the highest temperatures generated were in the range of 200-300℃.As the propulsion speed,cutting depth,and cutting angle were increased,the proportion of tensile fractures produced appeared to increase and the proportion of shear fractures decreased.As the rotational speed was increased,the proportion of tensile fractures decreased and the proportion of shear fractures increased.The results could provide useful information on the rock-breaking behavior involved and can be used to offer technical support for engineers using master-slave follow-up disc cutters in the field.展开更多
In ecological environments,the survival environment of species is often inhomogeneous,and the reproductive process is affected by time delay.System with nonlocal effects and delay can more accurately simulate changes ...In ecological environments,the survival environment of species is often inhomogeneous,and the reproductive process is affected by time delay.System with nonlocal effects and delay can more accurately simulate changes in population density.In this paper,we consider a reaction-diffusion-advection model with nonlocal delay and Dirichlet boundary conditions.First of all,we investigate the well-posedness of solution of model.Then,the existence of positive steady state is proofed by implicit function theorem.Based on a priori estimate for the eigenvalue,we prove the stability of the positive steady state and conclude the associated distribution of Hopf bifurcation.Our research indicates that the combined effects of nonlocal and time delays have a certain impact on the dynamics of the model.展开更多
Delay Alignment Modulation(DAM)is an innovative broadband modulation technique well-suited for millimeter Wave(mm Wave)and Terahertz(THz)massive Multiple-Input Multiple-Output(MIMO)communication systems.Leveraging the...Delay Alignment Modulation(DAM)is an innovative broadband modulation technique well-suited for millimeter Wave(mm Wave)and Terahertz(THz)massive Multiple-Input Multiple-Output(MIMO)communication systems.Leveraging the high spatial resolution and sparsity of multi-path channels,DAM effectively mitigates Inter-Symbol Interference(ISI)by aligning all multi-path components through a combination of delay pre-compensation(or post-compensation)and path-based beamforming.As such,ISI is eliminated while preserving multi-path power gains.In this paper,we investigate multi-user double-side DAM,which incorporates both delay pre-compensation at the transmitter and post-compensation at the receiver,in contrast to prior works that primarily focus on singleside DAM with only delay pre-compensation.Firstly,we derive the constraint on the number of introduced delays and formulate the corresponding delay pre/post-compensation vectors tailored for multi-user double-side DAM,given a specific number of delay compensations.Furthermore,we demonstrate that when the number of Base Stations(BSs)/User Equipment(UE)antennas is sufficiently large,single-side DAM—where delay compensation is performed only at the BS/UE—is preferable to double-side DAM,since the former results in less ISI to be spatially eliminated.Next,we propose two low-complexity path-based beamforming strategies based on the eigen-beamforming transmission and ISI-Zero Forcing(ZF),respectively.On this basis,we further analyze the achievable sum rates.Simulation results verify that with a sufficiently large number of BS/UE antennas,singleside DAM is adequate for ISI elimination.Moreover,compared to the benchmarking scheme of Orthogonal Frequency Division Multiplexing(OFDM),multi-user BS-side DAM achieves higher spectral efficiency and lower Peak-to-Average Power Ratio(PAPR).展开更多
The flight envelope of Air Turbo Rocket(ATR)engines is broader compared to conventional aero-engines,and designing a full-envelope controller using traditional methods poses significant challenges due to a burdensome ...The flight envelope of Air Turbo Rocket(ATR)engines is broader compared to conventional aero-engines,and designing a full-envelope controller using traditional methods poses significant challenges due to a burdensome design process.To address this issue,this paper proposes a self-learning neural network controller design method based on Reinforcement Learning(RL).Additionally,a method for predictive compensation and stability rewards is proposed to reduce the system oscillation caused by actuator delay.This approach simplifies the actuator to a firstorder inertial element exhibiting pure delay.A simulation environment for the ATR engineactuator system is first established.Based on this environment,a self-learning neural network controller using a predictive compensator and the Proximal Policy Optimization(PPO)algorithm is then developed.Furthermore,the temporal difference signals from the controller output are integrated into the reward function to enhance system stability.The proposed method is validated through numerical simulations and semi-physical experiments.The numerical simulation results demonstrate that the proposed method increases the system's tolerance to delays from 20 ms to 400 ms.Under an actuator delay of 400 ms,the average steady-state error remains less than0.1%,the overshoot is limited to 1%,and the settling time does not exceed 3 s.Moreover,compared to the traditional method,the proposed method exhibits higher adaptability to model errors and variations in flight conditions.In the conducted semi-physical simulation experiments,the proposed method achieves stable control of a real electric pump.展开更多
The development of polymeric materials that exhibit blue thermally activated delayed fluorescence(TADF)is of great interest for optoelectronic applications.However,achieving TADF in polymers often requires an elaborat...The development of polymeric materials that exhibit blue thermally activated delayed fluorescence(TADF)is of great interest for optoelectronic applications.However,achieving TADF in polymers often requires an elaborate monomer design.The high-energy local triplet state(^(3)LE)of carbazole complicates its application despite the molecular orbital arrangement being suitable for blue emission.Here,we present an approach to polymer design that makes it possible to solve this problem.We demonstrate the in situ formation of a TADF donor-acceptor system during Suzuki polycondensation,creating an extended carbazole-based donor matrix coupled with a triazine acceptor.The resulting polymer exhibited efficient TADF with a low energy gap(ΔE_(ST))value if a phenyl N-substituent,enabling essential electron delocalization,was present in the carbazole moiety.This work establishes a versatile platform for developing carbazole-based TADF polymers,overcoming the fundamental limitations that hinder their widespread application.展开更多
Delayed wound healing following radical gastrectomy remains an important yet underappreciated complication that prolongs hospitalization,increases costs,and undermines patient recovery.In An et al’s recent study,the ...Delayed wound healing following radical gastrectomy remains an important yet underappreciated complication that prolongs hospitalization,increases costs,and undermines patient recovery.In An et al’s recent study,the authors present a machine learning-based risk prediction approach using routinely available clinical and laboratory parameters.Among the evaluated algorithms,a decision tree model demonstrated excellent discrimination,achieving an area under the curve of 0.951 in the validation set and notably identifying all true cases of delayed wound healing at the Youden index threshold.The inclusion of variables such as drainage duration,preoperative white blood cell and neutrophil counts,alongside age and sex,highlights the pragmatic appeal of the model for early postoperative monitoring.Nevertheless,several aspects warrant critical reflection,including the reliance on a postoperative variable(drainage duration),internal validation only,and certain reporting inconsistencies.This letter underscores both the promise and the limitations of adopting interpretable machine learning models in perioperative care.We advocate for transparent reporting,external validation,and careful consideration of clinically actionable timepoints before integration into practice.Ultimately,this work represents a valuable step toward precision risk stratification in gastric cancer surgery,and sets the stage for multicenter,prospective evaluations.展开更多
Time-delayed blasting is widely utilized in engineering to mitigate induced vibration hazards and enhance fragmentation.The underlying vibration reduction principle is the decrease of the charge weight per delay,while...Time-delayed blasting is widely utilized in engineering to mitigate induced vibration hazards and enhance fragmentation.The underlying vibration reduction principle is the decrease of the charge weight per delay,while the potential for further vibration reduction remains debated,largely due to unclear underlying mechanisms.In light of the popularization of electronic detonators and the representativeness of double-hole configurationsfor multiple blastholes,it is essential to investigate the vibration characteristics induced by time-delayed double blastholes.Therefore,a series of doubleborehole experimental blasts was conducted in an underground roadway to clarify the variation in vibration from single-hole to dual-hole conditions.Based on the experimental data and inherent limitations,an exact full-fieldtheoretical model was further employed to systematically analyze the effects of delay time,charge length,and borehole inclination angle on vibrations induced by various doublehole configurations.The experimental data and theoretical analysis reveal that the general scaled distance effectively predicts vibrations in delayed blasting but does not reflectvibration reduction.Increasing delay time causes fluctuatingPPVs,which stabilize slightly above single-hole PPVs as delay times exceed a certain value.The delayed blasting primarily reduces near-fieldfrequencies.Longer charge lengths in double boreholes increase PPV levels and attenuation rates within a certain length,and the vibration behavior of combined long and short charge lengths is governed by the long blasthole.Larger blasthole inclination angles enhance vibration amplitude and reduce PPV attenuation rates.Optimizing inclination angles is more critical than adjusting delay times,and parallel boreholes offer the best vibration control.展开更多
A series of blue and blue‑green Ir(Ⅲ)complexes has been investigated theoretically to explore their electronic structures,photophysical properties,efficiency roll‑off effect,and thermal activation delayed fluorescenc...A series of blue and blue‑green Ir(Ⅲ)complexes has been investigated theoretically to explore their electronic structures,photophysical properties,efficiency roll‑off effect,and thermal activation delayed fluorescence(TADF)properties.All calculations were performed using density functional theory(DFT)and time‑dependent density functional theory(TDDFT).Calculations for electronic structures,frontier molecular orbital characteristics(which determine the efficiency roll‑off effect of the complexes),and photophysical properties were conducted using the Gaussian 09 software package.The calculation of spin‑orbit coupling matrix elements<T|HSOC|S>,which determine the TADF properties of the complexes,was performed using the ORCA software package.The calculation results show that the auxiliary ligand tetraphenylimidodiphosphinate(tpip),a strong electron‑withdrawing group,can mitigate the efficiency roll‑off effect of the complex.Furthermore,TADF is observed in one of the designed complexes,(F_(3)Phppy)_(2)Ir(tpip),where F_(3)Phppy=2‑[4‑(2,4,6‑trifluorophenyl)phenyl]pyridine.展开更多
Tropospheric zenith wet delay(ZWD)plays a vital role in the analysis of space geodetic observations.In recent years,machine learning methods have been increasingly applied to improve the accuracy of ZWD calculations.H...Tropospheric zenith wet delay(ZWD)plays a vital role in the analysis of space geodetic observations.In recent years,machine learning methods have been increasingly applied to improve the accuracy of ZWD calculations.However,a single machine learning model has limited generalization capabilities.To address these limitations,this study introduces a novel machine learning fusion(MLF)algorithm with stronger generalization capabilities to enhance ZWD modeling and prediction accuracy.The MLF algorithm utilizes a two-layer structure integrating extra trees(ET),backpropagation neural network(BPNN),and linear regression models.By comparing the root mean square error(RMSE)of these models,we found that both ET-based and MLF-based models outperform RF-based and BPNN-based models in terms of internal and external accuracy,across both surface meteorological data-based and blind models.The improvement in exte rnal accuracy is particularly significant in the blind models.Our re sults show that the MLF(with an RMSE of 3.93 cm)and ET(3.99 cm)models outperform the traditional GPT3model(4.07 cm),while the RF(4.21 cm)and BPNN(4.14 cm)have worse external accuracies than the GPT3 model.It is worth noting that the BPNN suffered from overfitting during external accuracy tests,which was avoided by the MLF.In summary,regardless of the availability of surface meteorological data,the MLF-based empirical models demonstrate superior internal and external accuracy compared to the other tested models in this study.展开更多
The increasing demand for flexible displays and wearable electronics has driven extensive efforts to develop stretchable organic lightemitting diodes(OLEDs).A critical challenge in this field is the creation of emissi...The increasing demand for flexible displays and wearable electronics has driven extensive efforts to develop stretchable organic lightemitting diodes(OLEDs).A critical challenge in this field is the creation of emissive layers that combine high efficiency with mechanical robustness.Thermally activated delayed fluorescence(TADF)materials have attracted significant attention as third-generation emitters capable of achieving 100%internal quantum efficiency;however,their application in stretchable OLEDs has been limited.In this study,we propose an elastomer doping strategy.Polyurethane(PU)is incorporated into TADF polymers to improve their mechanical flexibility while maintaining a high luminescent efficiency.The resulting composite films exhibited excellent TADF characteristics and remarkable stretchability(75%).OLEDs fabricated from these materials achieved a maximum external quantum efficiency(EQE)of 14.26%and a peak luminance of 73570 cd·m^(-2),with the PUdoped devices showing a significantly suppressed efficiency roll-off.Additionally,a fully stretchable OLED architecture was designed and operated under tensile strain to maintain stable electroluminescent performance.These results demonstrate that elastomer doping is an effective strategy for balancing the mechanical compliance with optoelectronic performance,offering a promising pathway for the development of high-performance stretchable OLEDs for flexible electronics.展开更多
Delayed neurocognitive recovery following anesthesia and surgery is a common complication in older adult patients.Synapses are fundamental to cognitive function.The activity of synapses heavily depends on the energy s...Delayed neurocognitive recovery following anesthesia and surgery is a common complication in older adult patients.Synapses are fundamental to cognitive function.The activity of synapses heavily depends on the energy supplied by synaptic mitochondria,which are significantly influenced by oxidative stress.Sirtuin 3 is a histone deacetylase located in the mitochondrial matrix that plays a pivotal role in regulating mitochondrial function.However,it remains unclear whether and how sirtuin 3 is involved in the development of delayed cognitive recovery.Therefore,in this study,we investigated the potential role of sirtuin 3 in synapses during delayed neurocognitive recovery.Our results showed that anesthesia and surgery induced cognitive impairment in mice and reduced sirtuin 3 protein expression.Overexpression of sirtuin 3 inhibited opening of the mitochondrial permeability transition pore by reducing acetylation of K166 on cyclophilin D and also rescued cognitive impairment.Aged mice carrying the cyclophilin D-K166R mutation exhibited significantly reduced cognitive impairment.Similarly,administering the mitochondrial permeability transition pore blocker,cyclosporine A,effectively alleviated the decline in synaptic mitochondrial function and cognitive impairment caused by anesthesia and surgery in aged mice.These results indicate that the sirtuin 3/cyclophilin D-K166/mPTP signaling pathway in hippocampal synaptic mitochondria is involved in delayed neurocognitive recovery of aged mice,suggesting this pathway could serve as a potential target for treatment.展开更多
Upon flaws of current blockchain platforms of heavyweight, large capacity of ledger, and time-consuming of synchronization of data, in this paper, we proposed a new paradigm of master-slave blockchain scheme(MSB) for ...Upon flaws of current blockchain platforms of heavyweight, large capacity of ledger, and time-consuming of synchronization of data, in this paper, we proposed a new paradigm of master-slave blockchain scheme(MSB) for pervasive computing that suitable for general PC, mobile device such as smart phones or PADs to participants in the working of mining and verification, in which we separated traditional blockchain model in 2 layer defined as master node layer and a series of slavery agents layer, then we proposed 2 approaches for partially computing model(PCM) and non-computing of model(NCM) in the MSB blockchain, Finally large amounts of simulations manifest the proposed master-slave blockchain scheme is feasible, extendible and suitable for pervasive computing especially in the 5 G generation environment, and can apply in the DRM-related applications.展开更多
This paper addresses a master-slave synchro- nization strategy for complex dynamic systems based on feedback control. This strategy is applied to 3-DOF pla- nar manipulators in order to obtain synchronization in such ...This paper addresses a master-slave synchro- nization strategy for complex dynamic systems based on feedback control. This strategy is applied to 3-DOF pla- nar manipulators in order to obtain synchronization in such complicated as chaotic motions of end-effectors. A chaotic curve is selected from Duffing equation as the trajectory of master end-effector and a piecewise approximation method is proposed to accurately represent this chaotic trajectory of end-effectors. The dynamical equations of master-slave manipulators with synchronization controller are derived, and the Lyapunov stability theory is used to determine the stability of this controlled synchronization system. In numer- ical experiments, the synchronous motions of end-effectors as well as three joint angles and torques of master-slave manipulators are studied under the control of the proposed synchronization strategy. It is found that the positive gain matrix affects the implementation of synchronization con- trol strategy. This synchronization control strategy proves the synchronization＇s feasibility and controllability for com- plicated motions generated by master-slave manipulators.展开更多
The networked synchronization problem of a class of master-slave chaotic systems with time-varying communication topologies is investigated in this paper. Based on algebraic graph theory and matrix theory, a simple li...The networked synchronization problem of a class of master-slave chaotic systems with time-varying communication topologies is investigated in this paper. Based on algebraic graph theory and matrix theory, a simple linear state feedback controller is designed to synchronize the master chaotic system and the slave chaotic systems with a time- varying communication topology connection. The exponential stability of the closed-loop networked synchronization error system is guaranteed by applying Lyapunov stability theory. The derived novel criteria are in the form of linear matrix inequalities （LMIs）, which are easy to examine and tremendously reduce the computation burden from the feedback matrices. This paper provides an alternative networked secure communication scheme which can be extended conveniently. An illustrative example is given to demonstrate the effectiveness of the proposed networked synchronization method.展开更多
As a key component of injection molding,multi-cavity hot runner(MCHR)system faces the crucial problem of polymer melt filling imbalance among the cavities.The thermal imbalance in the system has been considered as the...As a key component of injection molding,multi-cavity hot runner(MCHR)system faces the crucial problem of polymer melt filling imbalance among the cavities.The thermal imbalance in the system has been considered as the leading cause.Hence,the solution may rest with the synchronization of those heating processes in MCHR system.This paper proposes a’Master-Slave’generalized predictive synchronization control(MS-GPSC)method with’Mr.Slowest’strategy for preheating stage of MCHR system.The core of the proposed method is choosing the heating process with slowest dynamics as the’Master’to track the setpoint,while the other heating processes are treated as‘Slaves’tracking the output of’Master’.This proposed method is shown to have the good ability of temperature synchronization.The corresponding analysis is conducted on parameters tuning and stability,simulations and experiments show the strategy is effective.展开更多
A 3 DOF master-slave telerobot system is established for study on force telepresence technology. A force feedback and position control scheme is adopted in the bilateral force response control system,and force fidelit...A 3 DOF master-slave telerobot system is established for study on force telepresence technology. A force feedback and position control scheme is adopted in the bilateral force response control system,and force fidelity and controllability experiments demonstrate feasibility of the con-trol system.展开更多
文摘This paper investigates the problem of cluster synchronization of master-slave complex net-works with time-varying delay via linear and adaptive feedback pinning controls.We need not non-delayed and delayed coupling matrices to be symmetric or irreducible.We have the advantages of using adaptive control method to reduce control gain and pinning control technology to reduce cost.By con-structing Lyapunov function,some sufficient synchronization criteria are established.Finally,numerical examples are employed to illustrate the effectiveness of the proposed approach.
基金Supported by the National Natural Science Foundation of China under Grant Nos.60774039,60974024,and 61074089CityU Research Enhancement Fund 9360127,CityU SRG 7002355
文摘This paper concerns with the master-slave exponential synchronization analysis for a class of general Lur'esystems with time delay.Different from the previous methods based on the differential inequality technique, a newapproach is proposed to derive some new exponential synchronization criteria.The restriction that the control widthhas to be larger than the time delay is removed.This leads to a larger application scope for our method.Moreover, notranscendental equation is involved in the obtained result, which reduces the computational burden.Two examples aregiven to validate the theoretical results.
文摘This paper proposes an adaptive synchronization problem for the master and slave structure of linear systems with nonlinear perturbations and mixed time-varying delays comprising different discrete and distributed time delays. Using an appropriate Lyapunov-Krasovskii functional, some delay-dependent sufficient conditions and an adaptation law including the master-slave parame- ters are established for designing a delayed synchronization law in terms of linear matrix inequalities（LMIs）. The time-varying controller guarantees the H ∞ synchronization of the two coupled master and slave systems regardless of their initial states. Particularly, it is shown that the synchronization speed can be controlled by adjusting the updated gain of the synchronization signal. Two numerical examples are given to demonstrate the effectiveness of the method.
基金study was supported by the National Key Research and Development Program of China(Grant No.2023YFC2907202)the National Natural Science Foundation of China(Grant No.52404116)the Postdoctoral Fellowship Program of CPSF(Grant No.GZB20240129).
文摘In this paper,a self-developed master-slave follow-up disc cutter is used to conduct rock-breaking tests on hard sandstone samples.Different working parameters were employed in the tests(e.g.cutting depth,cutting speed,cutting angle,and rotational speed)in order to explore their influences on cutting performance.The results indicate that the thrust,torque,vibration velocity,and roughness all increased continuously with increase of the propulsion speed and cutting depth.At the same time,the specific energy consumption was found to decrease continuously.As the rotational speed was increased,the thrust increased at first and then decreased.In contrast,the torque and roughness continuously decreased,and the specific energy consumption and vibration speed continuously increased.When the cutting angle was increased,the thrust remained unchanged.However,the torque,specific energy consumption,and vibration speed all decreased continuously,and the roughness increased continuously.The temperature of the surface of the cutting tool was found to be relatively uniformly distributed during the rock-breaking process;the highest temperatures generated were in the range of 200-300℃.As the propulsion speed,cutting depth,and cutting angle were increased,the proportion of tensile fractures produced appeared to increase and the proportion of shear fractures decreased.As the rotational speed was increased,the proportion of tensile fractures decreased and the proportion of shear fractures increased.The results could provide useful information on the rock-breaking behavior involved and can be used to offer technical support for engineers using master-slave follow-up disc cutters in the field.
基金Supported by the Natural Science Foundation of Shanghai(23ZR1401700)National Natural Science Foundation of China(12471157)。
文摘In ecological environments,the survival environment of species is often inhomogeneous,and the reproductive process is affected by time delay.System with nonlocal effects and delay can more accurately simulate changes in population density.In this paper,we consider a reaction-diffusion-advection model with nonlocal delay and Dirichlet boundary conditions.First of all,we investigate the well-posedness of solution of model.Then,the existence of positive steady state is proofed by implicit function theorem.Based on a priori estimate for the eigenvalue,we prove the stability of the positive steady state and conclude the associated distribution of Hopf bifurcation.Our research indicates that the combined effects of nonlocal and time delays have a certain impact on the dynamics of the model.
基金supported in part by the Natural Science Foundation for Distinguished Young Scholars of Jiangsu Province under Grant BK20240070in part by the National Natural Science Foundation of China under Grant 62071114n part by the Fundamental Research Funds for the Central Universities under Grant 2242022k60004。
文摘Delay Alignment Modulation(DAM)is an innovative broadband modulation technique well-suited for millimeter Wave(mm Wave)and Terahertz(THz)massive Multiple-Input Multiple-Output(MIMO)communication systems.Leveraging the high spatial resolution and sparsity of multi-path channels,DAM effectively mitigates Inter-Symbol Interference(ISI)by aligning all multi-path components through a combination of delay pre-compensation(or post-compensation)and path-based beamforming.As such,ISI is eliminated while preserving multi-path power gains.In this paper,we investigate multi-user double-side DAM,which incorporates both delay pre-compensation at the transmitter and post-compensation at the receiver,in contrast to prior works that primarily focus on singleside DAM with only delay pre-compensation.Firstly,we derive the constraint on the number of introduced delays and formulate the corresponding delay pre/post-compensation vectors tailored for multi-user double-side DAM,given a specific number of delay compensations.Furthermore,we demonstrate that when the number of Base Stations(BSs)/User Equipment(UE)antennas is sufficiently large,single-side DAM—where delay compensation is performed only at the BS/UE—is preferable to double-side DAM,since the former results in less ISI to be spatially eliminated.Next,we propose two low-complexity path-based beamforming strategies based on the eigen-beamforming transmission and ISI-Zero Forcing(ZF),respectively.On this basis,we further analyze the achievable sum rates.Simulation results verify that with a sufficiently large number of BS/UE antennas,singleside DAM is adequate for ISI elimination.Moreover,compared to the benchmarking scheme of Orthogonal Frequency Division Multiplexing(OFDM),multi-user BS-side DAM achieves higher spectral efficiency and lower Peak-to-Average Power Ratio(PAPR).
基金co-supported by the National Science and Technology Major Project(No.J2019-Ⅲ-0010-0054)the National Natural Science Foundation of China(No.52336002)。
文摘The flight envelope of Air Turbo Rocket(ATR)engines is broader compared to conventional aero-engines,and designing a full-envelope controller using traditional methods poses significant challenges due to a burdensome design process.To address this issue,this paper proposes a self-learning neural network controller design method based on Reinforcement Learning(RL).Additionally,a method for predictive compensation and stability rewards is proposed to reduce the system oscillation caused by actuator delay.This approach simplifies the actuator to a firstorder inertial element exhibiting pure delay.A simulation environment for the ATR engineactuator system is first established.Based on this environment,a self-learning neural network controller using a predictive compensator and the Proximal Policy Optimization(PPO)algorithm is then developed.Furthermore,the temporal difference signals from the controller output are integrated into the reward function to enhance system stability.The proposed method is validated through numerical simulations and semi-physical experiments.The numerical simulation results demonstrate that the proposed method increases the system's tolerance to delays from 20 ms to 400 ms.Under an actuator delay of 400 ms,the average steady-state error remains less than0.1%,the overshoot is limited to 1%,and the settling time does not exceed 3 s.Moreover,compared to the traditional method,the proposed method exhibits higher adaptability to model errors and variations in flight conditions.In the conducted semi-physical simulation experiments,the proposed method achieves stable control of a real electric pump.
基金supported by the Russian Science Foundation (No. 25-13-00300)the Centre for Optical and Laser Materials Research (SPbSU) and Saint Petersburg State University for measuring the quantum yields of luminescence within the framework of research project(No.125021902439-8)。
文摘The development of polymeric materials that exhibit blue thermally activated delayed fluorescence(TADF)is of great interest for optoelectronic applications.However,achieving TADF in polymers often requires an elaborate monomer design.The high-energy local triplet state(^(3)LE)of carbazole complicates its application despite the molecular orbital arrangement being suitable for blue emission.Here,we present an approach to polymer design that makes it possible to solve this problem.We demonstrate the in situ formation of a TADF donor-acceptor system during Suzuki polycondensation,creating an extended carbazole-based donor matrix coupled with a triazine acceptor.The resulting polymer exhibited efficient TADF with a low energy gap(ΔE_(ST))value if a phenyl N-substituent,enabling essential electron delocalization,was present in the carbazole moiety.This work establishes a versatile platform for developing carbazole-based TADF polymers,overcoming the fundamental limitations that hinder their widespread application.
文摘Delayed wound healing following radical gastrectomy remains an important yet underappreciated complication that prolongs hospitalization,increases costs,and undermines patient recovery.In An et al’s recent study,the authors present a machine learning-based risk prediction approach using routinely available clinical and laboratory parameters.Among the evaluated algorithms,a decision tree model demonstrated excellent discrimination,achieving an area under the curve of 0.951 in the validation set and notably identifying all true cases of delayed wound healing at the Youden index threshold.The inclusion of variables such as drainage duration,preoperative white blood cell and neutrophil counts,alongside age and sex,highlights the pragmatic appeal of the model for early postoperative monitoring.Nevertheless,several aspects warrant critical reflection,including the reliance on a postoperative variable(drainage duration),internal validation only,and certain reporting inconsistencies.This letter underscores both the promise and the limitations of adopting interpretable machine learning models in perioperative care.We advocate for transparent reporting,external validation,and careful consideration of clinically actionable timepoints before integration into practice.Ultimately,this work represents a valuable step toward precision risk stratification in gastric cancer surgery,and sets the stage for multicenter,prospective evaluations.
基金supported by the National Natural Science Foundation of China(Grant Nos.42407267 and 52374152)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20220975).
文摘Time-delayed blasting is widely utilized in engineering to mitigate induced vibration hazards and enhance fragmentation.The underlying vibration reduction principle is the decrease of the charge weight per delay,while the potential for further vibration reduction remains debated,largely due to unclear underlying mechanisms.In light of the popularization of electronic detonators and the representativeness of double-hole configurationsfor multiple blastholes,it is essential to investigate the vibration characteristics induced by time-delayed double blastholes.Therefore,a series of doubleborehole experimental blasts was conducted in an underground roadway to clarify the variation in vibration from single-hole to dual-hole conditions.Based on the experimental data and inherent limitations,an exact full-fieldtheoretical model was further employed to systematically analyze the effects of delay time,charge length,and borehole inclination angle on vibrations induced by various doublehole configurations.The experimental data and theoretical analysis reveal that the general scaled distance effectively predicts vibrations in delayed blasting but does not reflectvibration reduction.Increasing delay time causes fluctuatingPPVs,which stabilize slightly above single-hole PPVs as delay times exceed a certain value.The delayed blasting primarily reduces near-fieldfrequencies.Longer charge lengths in double boreholes increase PPV levels and attenuation rates within a certain length,and the vibration behavior of combined long and short charge lengths is governed by the long blasthole.Larger blasthole inclination angles enhance vibration amplitude and reduce PPV attenuation rates.Optimizing inclination angles is more critical than adjusting delay times,and parallel boreholes offer the best vibration control.
文摘A series of blue and blue‑green Ir(Ⅲ)complexes has been investigated theoretically to explore their electronic structures,photophysical properties,efficiency roll‑off effect,and thermal activation delayed fluorescence(TADF)properties.All calculations were performed using density functional theory(DFT)and time‑dependent density functional theory(TDDFT).Calculations for electronic structures,frontier molecular orbital characteristics(which determine the efficiency roll‑off effect of the complexes),and photophysical properties were conducted using the Gaussian 09 software package.The calculation of spin‑orbit coupling matrix elements<T|HSOC|S>,which determine the TADF properties of the complexes,was performed using the ORCA software package.The calculation results show that the auxiliary ligand tetraphenylimidodiphosphinate(tpip),a strong electron‑withdrawing group,can mitigate the efficiency roll‑off effect of the complex.Furthermore,TADF is observed in one of the designed complexes,(F_(3)Phppy)_(2)Ir(tpip),where F_(3)Phppy=2‑[4‑(2,4,6‑trifluorophenyl)phenyl]pyridine.
基金funded by National Natural Science Foundation of China Key Program(12431014)Key Project of Hunan Education Department(22A0126)+1 种基金Natural Science Foundation of Hunan Province(2022JJ30555)Postgraduate Scientific Research Innovation Project of Xiangtan University(XDCX2024Y172)。
文摘Tropospheric zenith wet delay(ZWD)plays a vital role in the analysis of space geodetic observations.In recent years,machine learning methods have been increasingly applied to improve the accuracy of ZWD calculations.However,a single machine learning model has limited generalization capabilities.To address these limitations,this study introduces a novel machine learning fusion(MLF)algorithm with stronger generalization capabilities to enhance ZWD modeling and prediction accuracy.The MLF algorithm utilizes a two-layer structure integrating extra trees(ET),backpropagation neural network(BPNN),and linear regression models.By comparing the root mean square error(RMSE)of these models,we found that both ET-based and MLF-based models outperform RF-based and BPNN-based models in terms of internal and external accuracy,across both surface meteorological data-based and blind models.The improvement in exte rnal accuracy is particularly significant in the blind models.Our re sults show that the MLF(with an RMSE of 3.93 cm)and ET(3.99 cm)models outperform the traditional GPT3model(4.07 cm),while the RF(4.21 cm)and BPNN(4.14 cm)have worse external accuracies than the GPT3 model.It is worth noting that the BPNN suffered from overfitting during external accuracy tests,which was avoided by the MLF.In summary,regardless of the availability of surface meteorological data,the MLF-based empirical models demonstrate superior internal and external accuracy compared to the other tested models in this study.
基金supported by the National Natural Science Foundation of China(Nos.T2441002,22525506,U24A20137,and U22A6002)Strategic Priority Research Program of CAS(No.XDB0520101)+1 种基金National Key R&D Program of China(No.2023YFB3609000)CAS Project for Young Scientists in Basic Research(No.YSBR-053)。
文摘The increasing demand for flexible displays and wearable electronics has driven extensive efforts to develop stretchable organic lightemitting diodes(OLEDs).A critical challenge in this field is the creation of emissive layers that combine high efficiency with mechanical robustness.Thermally activated delayed fluorescence(TADF)materials have attracted significant attention as third-generation emitters capable of achieving 100%internal quantum efficiency;however,their application in stretchable OLEDs has been limited.In this study,we propose an elastomer doping strategy.Polyurethane(PU)is incorporated into TADF polymers to improve their mechanical flexibility while maintaining a high luminescent efficiency.The resulting composite films exhibited excellent TADF characteristics and remarkable stretchability(75%).OLEDs fabricated from these materials achieved a maximum external quantum efficiency(EQE)of 14.26%and a peak luminance of 73570 cd·m^(-2),with the PUdoped devices showing a significantly suppressed efficiency roll-off.Additionally,a fully stretchable OLED architecture was designed and operated under tensile strain to maintain stable electroluminescent performance.These results demonstrate that elastomer doping is an effective strategy for balancing the mechanical compliance with optoelectronic performance,offering a promising pathway for the development of high-performance stretchable OLEDs for flexible electronics.
基金supported by the National Natural Science Foundation of China,Nos.81701040(to HM),82071180(to HM),82271206(to TL),82171191(to YW),82371211(to YW)the Natural Science Foundation of Beijing,No.7212023(to HM)Key Subject of the Natural Science Foundation ofJiangsu Province for Colleges and Universities,No.23KJA320009(to YW).
文摘Delayed neurocognitive recovery following anesthesia and surgery is a common complication in older adult patients.Synapses are fundamental to cognitive function.The activity of synapses heavily depends on the energy supplied by synaptic mitochondria,which are significantly influenced by oxidative stress.Sirtuin 3 is a histone deacetylase located in the mitochondrial matrix that plays a pivotal role in regulating mitochondrial function.However,it remains unclear whether and how sirtuin 3 is involved in the development of delayed cognitive recovery.Therefore,in this study,we investigated the potential role of sirtuin 3 in synapses during delayed neurocognitive recovery.Our results showed that anesthesia and surgery induced cognitive impairment in mice and reduced sirtuin 3 protein expression.Overexpression of sirtuin 3 inhibited opening of the mitochondrial permeability transition pore by reducing acetylation of K166 on cyclophilin D and also rescued cognitive impairment.Aged mice carrying the cyclophilin D-K166R mutation exhibited significantly reduced cognitive impairment.Similarly,administering the mitochondrial permeability transition pore blocker,cyclosporine A,effectively alleviated the decline in synaptic mitochondrial function and cognitive impairment caused by anesthesia and surgery in aged mice.These results indicate that the sirtuin 3/cyclophilin D-K166/mPTP signaling pathway in hippocampal synaptic mitochondria is involved in delayed neurocognitive recovery of aged mice,suggesting this pathway could serve as a potential target for treatment.
基金supported by the National Natural Science Foundation of China under Grant 61272519the Research Funds of Blockchain Joint Lab between BUPT and BCTthe joint Blockchain and Security Lab between BUPT and CAPSTONE
文摘Upon flaws of current blockchain platforms of heavyweight, large capacity of ledger, and time-consuming of synchronization of data, in this paper, we proposed a new paradigm of master-slave blockchain scheme(MSB) for pervasive computing that suitable for general PC, mobile device such as smart phones or PADs to participants in the working of mining and verification, in which we separated traditional blockchain model in 2 layer defined as master node layer and a series of slavery agents layer, then we proposed 2 approaches for partially computing model(PCM) and non-computing of model(NCM) in the MSB blockchain, Finally large amounts of simulations manifest the proposed master-slave blockchain scheme is feasible, extendible and suitable for pervasive computing especially in the 5 G generation environment, and can apply in the DRM-related applications.
基金supported by the Key Project of Chinese Ministry of Education(108037)the National Natural Science Foundation of China(10402008 and 50535010)
文摘This paper addresses a master-slave synchro- nization strategy for complex dynamic systems based on feedback control. This strategy is applied to 3-DOF pla- nar manipulators in order to obtain synchronization in such complicated as chaotic motions of end-effectors. A chaotic curve is selected from Duffing equation as the trajectory of master end-effector and a piecewise approximation method is proposed to accurately represent this chaotic trajectory of end-effectors. The dynamical equations of master-slave manipulators with synchronization controller are derived, and the Lyapunov stability theory is used to determine the stability of this controlled synchronization system. In numer- ical experiments, the synchronous motions of end-effectors as well as three joint angles and torques of master-slave manipulators are studied under the control of the proposed synchronization strategy. It is found that the positive gain matrix affects the implementation of synchronization con- trol strategy. This synchronization control strategy proves the synchronization＇s feasibility and controllability for com- plicated motions generated by master-slave manipulators.
基金supported by the National Natural Science Foundation of China (Grant Nos. 60904046, 60972164, 60974071, and 60804006)the Special Fund for Basic Scientific Research of Central Colleges, Northeastern University, China (Grant No. 090604005)+2 种基金the Science and Technology Program of Shenyang (Grant No. F11-264-1-70)the Program for Liaoning Excellent Talents in University (Grant No. LJQ2011137)the Program for Liaoning Innovative Research Team in University (Grant No. LT2011019)
文摘The networked synchronization problem of a class of master-slave chaotic systems with time-varying communication topologies is investigated in this paper. Based on algebraic graph theory and matrix theory, a simple linear state feedback controller is designed to synchronize the master chaotic system and the slave chaotic systems with a time- varying communication topology connection. The exponential stability of the closed-loop networked synchronization error system is guaranteed by applying Lyapunov stability theory. The derived novel criteria are in the form of linear matrix inequalities （LMIs）, which are easy to examine and tremendously reduce the computation burden from the feedback matrices. This paper provides an alternative networked secure communication scheme which can be extended conveniently. An illustrative example is given to demonstrate the effectiveness of the proposed networked synchronization method.
基金supported in part by National Natural Science Foundation of China(62203127)Basic and Applied Basic Research Project of Guangzhou City(2023A04J1712)+1 种基金The Foshan-HKUST Projects Program(FSUST19-FYTRI01)GDAS’Project of Science and Technology Development(2020GDASYL-20200202001).
文摘As a key component of injection molding,multi-cavity hot runner(MCHR)system faces the crucial problem of polymer melt filling imbalance among the cavities.The thermal imbalance in the system has been considered as the leading cause.Hence,the solution may rest with the synchronization of those heating processes in MCHR system.This paper proposes a’Master-Slave’generalized predictive synchronization control(MS-GPSC)method with’Mr.Slowest’strategy for preheating stage of MCHR system.The core of the proposed method is choosing the heating process with slowest dynamics as the’Master’to track the setpoint,while the other heating processes are treated as‘Slaves’tracking the output of’Master’.This proposed method is shown to have the good ability of temperature synchronization.The corresponding analysis is conducted on parameters tuning and stability,simulations and experiments show the strategy is effective.
文摘A 3 DOF master-slave telerobot system is established for study on force telepresence technology. A force feedback and position control scheme is adopted in the bilateral force response control system,and force fidelity and controllability experiments demonstrate feasibility of the con-trol system.
