This paper deals with the delay-dependent stabilization problem for singular systems with Markovian jump parameters and time delays.A delay-dependent condition is established for the considered system to be regular,im...This paper deals with the delay-dependent stabilization problem for singular systems with Markovian jump parameters and time delays.A delay-dependent condition is established for the considered system to be regular,impulse free and stochastically stable.Based on the condition,a design algorithm of the desired state feedback controller which guarantees the resultant closed-loop system to be regular,impulse free and stochastically stable is proposed in terms of a set of strict linear matrix inequalities(LMIs).Numerical examples show the effectiveness of the proposed methods.展开更多
The stabilization problem for a class of linear continuous-time systems with time-varying non differentiable delay is solved while imposing positivity in closed-loop. In particular, the synthesis of state-feedback con...The stabilization problem for a class of linear continuous-time systems with time-varying non differentiable delay is solved while imposing positivity in closed-loop. In particular, the synthesis of state-feedback controllers is studied by giving sufficient conditions in terms of linear matrix inequalities(LMIs). The obtained results are then extended to systems with non positive delay matrix by applying a memory controller. The effectiveness of the proposed method is shown by using numerical examples.展开更多
This paper presents delay-dependent stability analysis and controller synthesis methods for discrete-time Takagi-Sugeno （T-S） fuzzy systems with time delays. The T-S fuzzy system is transformed to an equivalent swit...This paper presents delay-dependent stability analysis and controller synthesis methods for discrete-time Takagi-Sugeno （T-S） fuzzy systems with time delays. The T-S fuzzy system is transformed to an equivalent switching fuzzy system. Consequently, the delay-dependent stabilization criteria are derived for the switching fuzzy system based on the piecewise Lyapunov function. The proposed conditions are given in terms of linear matrix inequalities （LMIs）. The interactions among the fuzzy subsystems are considered in each subregion, and accordingly the proposed conditions are less conservative than the previous results. Since only a set of LMIs is involved, the controller design is quite simple and numerically tractable. Finally, a design example is given to show the validity of the proposed method.展开更多
In this paper, a class of discontinuous neutral-type neural networks (NTNNs) with proportional delays is considered. The targets of the paper are to study the problem of periodic solutions and fixed-time (FXT) stabili...In this paper, a class of discontinuous neutral-type neural networks (NTNNs) with proportional delays is considered. The targets of the paper are to study the problem of periodic solutions and fixed-time (FXT) stabilization of the addressed neural networks. In order to complete the targets, based on set-valued map, differential inclusions theory, coincidence theorem and Hölder inequality technique, some new proportional delay-dependent criteria shown by the inequalities are derived. Based on the fact of the existence of solution, further by applying the FXT stability lemmas and equivalent transformation, the zero solution of closed-loop system achieves FXT stabilization and the corresponding settling-times are estimated. Some previous related works on NTNNs are extended. Finally, one typical example is provided to show the effectiveness of the established results.展开更多
As well-known,prescribed-time stabilizing design faces the need of using time-varying high gains which escape to infinity as time approaches the desired instant.In the presence of measurement noise,the corresponding s...As well-known,prescribed-time stabilizing design faces the need of using time-varying high gains which escape to infinity as time approaches the desired instant.In the presence of measurement noise,the corresponding state response is also significantly amplified that leads to the lack of robustness in the closedloop implementation.In order to eliminate this drawback,the implicit Euler discretization of the closed-loop in question is recently developed in where desired robustness properties are conserved beyond the prescribedtime interval while also bounded state dynamics are ensured in the presence of measurement noise.Along this line,stabilizing prescribed-observer-based output feedback algorithms and their digital implementation are reviewed.For tutorial value,the underlying state feedback and observer designs are recalled side by side in continuous-and discrete-time perspectives,followed by the desired output feedback design.Open problems,calling for future investigation,conclude the review.展开更多
Flexibly interconnected distribution networks(FIDN)offer improved operational efficiency and operational control flexibility of power distribution systems through DC interconnection links,and have gradually become the...Flexibly interconnected distribution networks(FIDN)offer improved operational efficiency and operational control flexibility of power distribution systems through DC interconnection links,and have gradually become the main form of distribution networks.Aiming at the impact of constant power loads and converter transmission power variations in FIDN system stability,this paper presents an impedance reshaping based stability analysis and stabilization control to enhance the stability of the interconnected system and improve the system’s dynamic load response capability.Firstly,a small-single based equivalent impedance model of FIDN system,which consists flexibly interconnected equipment,energy storage,PV units,and constant power loads,is presented,and the total output and input impedance of the DC distribution network are derived.Secondly,the impacts of constant power loads and transmission power variations on the small-signal stability of FIDN system are analyzed through Nyquist stability curves using the impedance ratio criterion.Then,an impedance reshaping-based stability enhancement strategy for the FIDN system is proposed,which can significantly improve the system stability under the operating conditions of constant power loads and transmission power variations.Finally,a MATLAB/Simulink simulation model is built and tested.The results demonstrate that the proposed impedance reshaping strategy effectively mitigates voltage dips,surges,and DC bus fluctuations,shortens transient responses under power variations,and enables rapid stability recovery with reduced voltage drop during severe AC sags.展开更多
To enhance the stabilization performance of red-bedded mudstone subgrade soil,a novel synergistic technique combining microorganisms and quicklime was developed and evaluated through comprehensive physical,mechanical,...To enhance the stabilization performance of red-bedded mudstone subgrade soil,a novel synergistic technique combining microorganisms and quicklime was developed and evaluated through comprehensive physical,mechanical,and microstructural analyses.The results demonstrated that quicklime significantly improved the pore structure by increasing the proportion of pores with diameters in the range of 0.5-50μm,thereby facilitating microbial migration and calcium carbonate precipitation.The proposed technique effectively enhanced cementitious material production(cementation rate:6.83%),unconfined compressive strength(1.63 MPa),and resistance to swelling and deformation(swelling rate:0.26%).The observed synergistic effect can be attributed to two primary mechanisms.First,quicklime promotes soil particle agglomeration,resulting in larger pores that enable bacterial mobility and provide optimal microenvironments for microbial activity.Second,during curing,quicklime undergoes hydration and ionization,releasing Ca^(2+)and OH^(−)ions.The Ca^(2+)ions serve as calcium sources for microbial-induced carbonate precipitation,while the OH−ions react with SiO_(2)and Al_(2)O_(3) to form hydrated gels that develop a skeletal soil structure.Meanwhile,the exothermic reaction further accelerates calcium carbonate deposition within the agglomerated pores.展开更多
Rapid industrialization in China has caused significant environmental challenges,particularly heavy metal pollution from mine tailings.Toxic heavy metals such as lead(Pb),cadmium(Cd),and mercury(Hg)are released during...Rapid industrialization in China has caused significant environmental challenges,particularly heavy metal pollution from mine tailings.Toxic heavy metals such as lead(Pb),cadmium(Cd),and mercury(Hg)are released during the processing of mining wastewater and leaching of mine tailings.Owing to their excellent physicochemical properties,cementitious materials are widely used for the solidification/stabilization of heavy metals,immobilizing heavy metals via two distinct mechanisms.Physically,their favorable characteristics,including high mechanical strength,low porosity,and durable matrix,create effective barriers.Chemically,the alkaline environment facilitates the precipitation of metal hydroxides/carbonates.Conversely,hydration products(calcium silicate hydrate gels and ettringite)contribute to immobilization through adsorption and physical encapsulation.This study systematically investigated the migration mechanisms of heavy metal contaminants in mine tailings;further,it elucidated the multifaceted immobilization pathways of cementitious materials,which involve synergistic adsorption,precipitation,and encapsulation by hydration products combined with homocrystalline substitution.A comprehensive analysis indicated that cementitious materials significantly reduced the mobility and bioavailability of heavy metals.Nonetheless,their long-term stability and potential environmental impact require further investigation.This study aims to provide theoretical support for environmental management and sustainable resource utilization,and to explore the broader application potential of cementitious technology for heavy metal stabilization,thereby establishing a theoretical foundation for future research on heavy metals in low-cement solidified/stabilized tailings.展开更多
Lithium-rich layered oxides(LRLOs)are promising cathode materials due to their high specific capacity,energy density,and operating voltage.However,their performance is hindered by the limited redox activity of transit...Lithium-rich layered oxides(LRLOs)are promising cathode materials due to their high specific capacity,energy density,and operating voltage.However,their performance is hindered by the limited redox activity of transition metals,leading to oxygen redox instability,oxygen release,and capacity degradation.To address these issues,we propose an innovative lattice-oxygen modulation(LOM)strategy that incorporates Mn^(3+)and Ti^(4+)into the Li_(1.2)Cr_(0.3)Mn_(0.4)Ti_(0.1)O_(2) system,effectively mitigating Cr migration,stabilizing oxygen redox reactions,and reinforcing structural integrity.This results in improved electrochemical performance,as demonstrated by a 56.5 mAh g^(−1) increase in initial discharge capacity to 364.2 mAh g^(−1),with 71.3%capacity retention after 30 cycles,reflecting a 20.2%improvement in cycling stability.Density functional theory(DFT)calculations confirm enhanced Cr redox reversibility and reduced oxygen evolution,further strengthening structural stability.These synergistic effects highlight the pivotal role of the LOM strategy in optimizing both electrochemical performance and structural integrity,offering a scalable pathway to improve capacity and cycling stability in lithium-rich cathodes.展开更多
This paper explores the adaptive exponentially designated-time stabilization issue via event-triggered feedback for a kind of uncertain high-order nonlinear systems.The motivation mainly comes from the following two c...This paper explores the adaptive exponentially designated-time stabilization issue via event-triggered feedback for a kind of uncertain high-order nonlinear systems.The motivation mainly comes from the following two challenges:the undesired singularity problem arising from infinite control gains at the prescribed-time instant,the effective trade-off between the control amplitude and the triggering duration.The goal is to build an event-triggered mechanism comprising a skillful triggered rule alongside a time-dependent threshold.Utilizing the designed control strategy,the solutions'existence and the prevention of Zeno phenomenon are successfully guaranteed by using a new transformation equipped with a time-varying function and redesigning the continuous state-feedback dominance approach with an array of integral functions involving embedded sign functions.Better than existing prescribed-time methods,our approach not only ensures that state variables converge to a small compact set before a designated time and stay there henceforth,and converge to the origin exponentially,but also ensures that the controller continuously works on the whole-time horizon.Two illustrative examples are given to show the effectiveness of the devised scheme.展开更多
Unconfined Compressive Strength(UCS)is a key parameter for the assessment of the stability and performance of stabilized soils,yet traditional laboratory testing is both time and resource intensive.In this study,an in...Unconfined Compressive Strength(UCS)is a key parameter for the assessment of the stability and performance of stabilized soils,yet traditional laboratory testing is both time and resource intensive.In this study,an interpretable machine learning approach to UCS prediction is presented,pairing five models(Random Forest(RF),Gradient Boosting(GB),Extreme Gradient Boosting(XGB),CatBoost,and K-Nearest Neighbors(KNN))with SHapley Additive exPlanations(SHAP)for enhanced interpretability and to guide feature removal.A complete dataset of 12 geotechnical and chemical parameters,i.e.,Atterberg limits,compaction properties,stabilizer chemistry,dosage,curing time,was used to train and test the models.R2,RMSE,MSE,and MAE were used to assess performance.Initial results with all 12 features indicated that boosting-based models(GB,XGB,CatBoost)exhibited the highest predictive accuracy(R^(2)=0.93)with satisfactory generalization on test data,followed by RF and KNN.SHAP analysis consistently picked CaO content,curing time,stabilizer dosage,and compaction parameters as the most important features,aligning with established soil stabilization mechanisms.Models were then re-trained on the top 8 and top 5 SHAP-ranked features.Interestingly,GB,XGB,and CatBoost maintained comparable accuracy with reduced input sets,while RF was moderately sensitive and KNN was somewhat better owing to reduced dimensionality.The findings confirm that feature reduction through SHAP enables cost-effective UCS prediction through the reduction of laboratory test requirements without significant accuracy loss.The suggested hybrid approach offers an explainable,interpretable,and cost-effective tool for geotechnical engineering practice.展开更多
The application of poly(butylene adipate-co-terephthalate)(PBAT)biodegradable plastics has long been constrained by insufficient light aging resistance.Hindered amine light stabilizers(HALSs),known as eco-friendly add...The application of poly(butylene adipate-co-terephthalate)(PBAT)biodegradable plastics has long been constrained by insufficient light aging resistance.Hindered amine light stabilizers(HALSs),known as eco-friendly additives,can scavenge free radicals to enhance polymer durability.However,rough choices have resulted in wastage of resources and environmental pressure.Based on the application of plastic films as the background for use,this study systematically evaluates application effects of five HALSs.The films underwent accelerated aging for various durations and were further investigated by a combination of experiments and molecular simulation.Results showed that all HALSs mitigated PBAT light aging,with Chimassorb-944(UV-944)and Tinuvin-770(UV-770)performing the best for real applications.Quantum chemical calculation results showed that UV-944 had stronger anti migration ability.After 300 h of aging,films with UV-944 and UV-770 retained superior tensile strength and elongation at break in the transverse direction compared to neat PBAT films.Polymeric HALSs provided better long-term stability than small-molecule ones.Further spectra analysis indicated that stronger C―O bonds in HALS/PBAT composites correlated with improved photostability.This study offers valuable insights into improving weather resistance of PBAT biodegradable films and optimizing the real application of HALSs.展开更多
The stability and stabilization of a class of linear switched time-varying delay systems are investigated. A piecewise quadratic Lyapunov function （PWQLF） is constructed and is used to obtain the stability condition...The stability and stabilization of a class of linear switched time-varying delay systems are investigated. A piecewise quadratic Lyapunov function （PWQLF） is constructed and is used to obtain the stability conditions based on the linear matrix inequalities （LMIs）. The stabilizing controller for this class of system is then designed and the solution of the desired controller can be obtained by a cone complementary linearization algorithm. Numerical examples are provided to illustrate the less conservativeness of the new stability and the validity of the controller design procedures.展开更多
Rechargeable lithium–sulfur(Li–S)batteries are considered promising next-generation energy storage systems owing to their high theoretical energy density,but their application is hindered by the shuttle effect arisi...Rechargeable lithium–sulfur(Li–S)batteries are considered promising next-generation energy storage systems owing to their high theoretical energy density,but their application is hindered by the shuttle effect arising from dissolved lithium polysulfides(LiPSs).Herein,we design an optimized electrolyte to achieve long-term stability by employing an appropriate low-polarity solvent.A combination of diethyl ether(DEE)and 1,2-dimethoxyethane(DME)was selected to improve Li metal stability even in the presence of LiPSs.The DEE/DME electrolyte not only suppresses parasitic reactions between Li and LiPSs but also promotes uniform Li deposition.Moreover,operando optical microscopy was employed to directly visualize electrolyte stability and dendrite evolution in real time,while quantitative analysis was conducted via normalized hue index and contour image mapping.The enhanced anode stability of the DEE/DME electrolyte enabled excellent cycling performance,retaining 80.14%of its initial capacity after300 cycles at 3 C,while maintaining superior performance under practical conditions with high sulfur loading and a low E/S ratio.These findings highlight that solvent properties critically influence Li metal stabilization in Li–S batteries and underscore the significance of solvent engineering in electrolyte design.展开更多
This paper deals with the problem of delay-dependent stability and stabilization for networked control systems(NCSs)with multiple time-delays.In view of multi-input and multi-output(MIMO)NCSs with many independent sen...This paper deals with the problem of delay-dependent stability and stabilization for networked control systems(NCSs)with multiple time-delays.In view of multi-input and multi-output(MIMO)NCSs with many independent sensors and actuators,a continuous time model with distributed time-delays is proposed.Utilizing the Lyapunov stability theory combined with linear matrix inequalities(LMIs)techniques,some new delay-dependent stability criteria for NCSs in terms of generalized Lyapunov matrix equation and LMIs are derived.Stabilizing controller via state feedback is formulated by solving a set of LMIs.Compared with the reported methods,the proposed methods give a less conservative delay bound and more general results.Numerical example and simulation show that the methods are less conservative and more effective.展开更多
Superoxide dismutase 1(SOD1)is a thermodynamically stable,zinc and copper binding homodimeric enzyme responsible for breaking down superoxide radicals.More than 200,mostly missense,mutations spread throughout the SOD1...Superoxide dismutase 1(SOD1)is a thermodynamically stable,zinc and copper binding homodimeric enzyme responsible for breaking down superoxide radicals.More than 200,mostly missense,mutations spread throughout the SOD1 gene are associated with the fatal neurodegenerative disease,amyotrophic lateral sclerosis(ALS).A unifying feature of ALS-associated SOD1 mutations is the destabilization of the SOD1 protein structure,increasing the propensity for misfolding and subsequent pathological aggregation.Post-mortem analysis of SOD1-associated ALS tissue shows the accumulation of misfolded SOD1 protein and ubiquitinated SOD1 inclusions within motor neurons.Misfolded SOD1 accumulation and aggregates are implicated in cellular dysfunction via a number of disparate but critical processes,including endoplasmic reticulum stress,oxidative damage,proteasome dysfunction,axonal transport abnormalities and synaptic dysfunction;culminating in motor neuron degeneration associated with ALS.展开更多
In this paper, delay-dependent stability analysis and robust stabilization for uncertain singular time-delay systems are addressed. By using Jensen integral inequality, an improved delay-dependent criterion of admissi...In this paper, delay-dependent stability analysis and robust stabilization for uncertain singular time-delay systems are addressed. By using Jensen integral inequality, an improved delay-dependent criterion of admissibility for singular time-delay systems is proposed in terms of linear matrix inequality （LMI）. Our new proposed criterion is less conservative and the numerical complexity is smaller than the existing ones. Based on this criterion, a state feedback controller is designed to ensure that the uncertain singular time-delay system is admissible. Finally, three numerical examples are employed to illustrate the effectiveness of the proposed method.展开更多
This paper investigates the problem of delay-dependent robust stabilization for uncertain singular systems with discrete and distributed delays in terms of linear matrix inequality （LMI） approach. Based on a delay-d...This paper investigates the problem of delay-dependent robust stabilization for uncertain singular systems with discrete and distributed delays in terms of linear matrix inequality （LMI） approach. Based on a delay-dependent stability condition for the nominal system, a state feedback controller is designed, which guarantees the resultant closed- loop system to be robustly stable. An explicit expression for the desired controller is also given by solving a set of matrix inequalities. Some numerical examples are provided to illustrate the less conservativeness of the proposed methods.展开更多
This note deals with the problem of stabilization/stability for neutral systems with nonlinear perturbations. A new stabilization/stability scheme is presented. Using improved Lyapunov functionals, less conservative s...This note deals with the problem of stabilization/stability for neutral systems with nonlinear perturbations. A new stabilization/stability scheme is presented. Using improved Lyapunov functionals, less conservative stabilization/stability conditions are derived for such systems based on linear matrix inequalities （LMI）. Numerical examples are provided to show that the proposed results significantly improve the allowed upper bounds of the delay size over some existing ones in the literature.展开更多
To alleviate the conservativeness of the stability criterion for Takagi-Sugeno （T-S） fuzzy time-delay systems, a new delay-dependent stability criterion was proposed by introducing a new augmented Lyapunov function ...To alleviate the conservativeness of the stability criterion for Takagi-Sugeno （T-S） fuzzy time-delay systems, a new delay-dependent stability criterion was proposed by introducing a new augmented Lyapunov function with an additional triple-integral term, which was firstly u3ed to derive the stability criterion for T-S fuzzy time-delay systems. By the same approach, the robust stability issue for fuzzy time-delay systems with uncertain parameters was also considered. On the other hand, in order to enhance the design flexibility, a new design approach for uncertain fuzzy time-delay systems under imperfect premise matching was also proposed, which allows the fuzzy controller to employ different membership functions from the fuzzy time-delay model. By the numerical examples, the proposed stability conditions are less conservative in the sense of getting larger allowable time-delay and obtaining smaller feedback control gains. For instance, when the allowable time-delay increases from 7.3 s to 12 s for an uncertain T-S fuzzy control system with time-delay, the norm of the feedback gains decreases from （34.299 2, 38.560 3） to （10.073 3, 11.349 0）, respectively. Meanwhile, the effectiveness of the proposed design method was illustrated by the last example with the robustly stable curves of system state under the initial condition of x（0） = [3 -1].展开更多
基金supported by the National Creative Research Groups Science Foundation of China(No.60721062)the National High Technology Research and Development Program of China(863 Program)(2006AA04 Z182)the National Natural Science Foundation of China(No.60736021)
文摘This paper deals with the delay-dependent stabilization problem for singular systems with Markovian jump parameters and time delays.A delay-dependent condition is established for the considered system to be regular,impulse free and stochastically stable.Based on the condition,a design algorithm of the desired state feedback controller which guarantees the resultant closed-loop system to be regular,impulse free and stochastically stable is proposed in terms of a set of strict linear matrix inequalities(LMIs).Numerical examples show the effectiveness of the proposed methods.
文摘The stabilization problem for a class of linear continuous-time systems with time-varying non differentiable delay is solved while imposing positivity in closed-loop. In particular, the synthesis of state-feedback controllers is studied by giving sufficient conditions in terms of linear matrix inequalities(LMIs). The obtained results are then extended to systems with non positive delay matrix by applying a memory controller. The effectiveness of the proposed method is shown by using numerical examples.
基金supported by the National Natural Science Foundation of China (No.60804021)
文摘This paper presents delay-dependent stability analysis and controller synthesis methods for discrete-time Takagi-Sugeno （T-S） fuzzy systems with time delays. The T-S fuzzy system is transformed to an equivalent switching fuzzy system. Consequently, the delay-dependent stabilization criteria are derived for the switching fuzzy system based on the piecewise Lyapunov function. The proposed conditions are given in terms of linear matrix inequalities （LMIs）. The interactions among the fuzzy subsystems are considered in each subregion, and accordingly the proposed conditions are less conservative than the previous results. Since only a set of LMIs is involved, the controller design is quite simple and numerically tractable. Finally, a design example is given to show the validity of the proposed method.
基金supported by Social Science Fund of Hunan province(Grant No.22JD074)the Research Foundation of Education Bureau of Hunan province(Grant No.22B0912).
文摘In this paper, a class of discontinuous neutral-type neural networks (NTNNs) with proportional delays is considered. The targets of the paper are to study the problem of periodic solutions and fixed-time (FXT) stabilization of the addressed neural networks. In order to complete the targets, based on set-valued map, differential inclusions theory, coincidence theorem and Hölder inequality technique, some new proportional delay-dependent criteria shown by the inequalities are derived. Based on the fact of the existence of solution, further by applying the FXT stability lemmas and equivalent transformation, the zero solution of closed-loop system achieves FXT stabilization and the corresponding settling-times are estimated. Some previous related works on NTNNs are extended. Finally, one typical example is provided to show the effectiveness of the established results.
文摘As well-known,prescribed-time stabilizing design faces the need of using time-varying high gains which escape to infinity as time approaches the desired instant.In the presence of measurement noise,the corresponding state response is also significantly amplified that leads to the lack of robustness in the closedloop implementation.In order to eliminate this drawback,the implicit Euler discretization of the closed-loop in question is recently developed in where desired robustness properties are conserved beyond the prescribedtime interval while also bounded state dynamics are ensured in the presence of measurement noise.Along this line,stabilizing prescribed-observer-based output feedback algorithms and their digital implementation are reviewed.For tutorial value,the underlying state feedback and observer designs are recalled side by side in continuous-and discrete-time perspectives,followed by the desired output feedback design.Open problems,calling for future investigation,conclude the review.
基金supported by the key technology project of China Southern Power Grid Corporation(GZKJXM20220041)partly by theNational Key Research andDevelopment Plan(2022YFE0205300).
文摘Flexibly interconnected distribution networks(FIDN)offer improved operational efficiency and operational control flexibility of power distribution systems through DC interconnection links,and have gradually become the main form of distribution networks.Aiming at the impact of constant power loads and converter transmission power variations in FIDN system stability,this paper presents an impedance reshaping based stability analysis and stabilization control to enhance the stability of the interconnected system and improve the system’s dynamic load response capability.Firstly,a small-single based equivalent impedance model of FIDN system,which consists flexibly interconnected equipment,energy storage,PV units,and constant power loads,is presented,and the total output and input impedance of the DC distribution network are derived.Secondly,the impacts of constant power loads and transmission power variations on the small-signal stability of FIDN system are analyzed through Nyquist stability curves using the impedance ratio criterion.Then,an impedance reshaping-based stability enhancement strategy for the FIDN system is proposed,which can significantly improve the system stability under the operating conditions of constant power loads and transmission power variations.Finally,a MATLAB/Simulink simulation model is built and tested.The results demonstrate that the proposed impedance reshaping strategy effectively mitigates voltage dips,surges,and DC bus fluctuations,shortens transient responses under power variations,and enables rapid stability recovery with reduced voltage drop during severe AC sags.
基金supported by the National Natural Science Foundation of China(Grant No.U22A20600)by the Natural Science Foundation of Hubei Province(Grant No.2025AFA015).
文摘To enhance the stabilization performance of red-bedded mudstone subgrade soil,a novel synergistic technique combining microorganisms and quicklime was developed and evaluated through comprehensive physical,mechanical,and microstructural analyses.The results demonstrated that quicklime significantly improved the pore structure by increasing the proportion of pores with diameters in the range of 0.5-50μm,thereby facilitating microbial migration and calcium carbonate precipitation.The proposed technique effectively enhanced cementitious material production(cementation rate:6.83%),unconfined compressive strength(1.63 MPa),and resistance to swelling and deformation(swelling rate:0.26%).The observed synergistic effect can be attributed to two primary mechanisms.First,quicklime promotes soil particle agglomeration,resulting in larger pores that enable bacterial mobility and provide optimal microenvironments for microbial activity.Second,during curing,quicklime undergoes hydration and ionization,releasing Ca^(2+)and OH^(−)ions.The Ca^(2+)ions serve as calcium sources for microbial-induced carbonate precipitation,while the OH−ions react with SiO_(2)and Al_(2)O_(3) to form hydrated gels that develop a skeletal soil structure.Meanwhile,the exothermic reaction further accelerates calcium carbonate deposition within the agglomerated pores.
基金supported by the National Natural Science Foundation of China(No.52374121)the Henan Province Science and Technology Research and Development Joint Fund,China(No.235200810016)the National Key Research and Development Program,China(No.2023YFC2907203).
文摘Rapid industrialization in China has caused significant environmental challenges,particularly heavy metal pollution from mine tailings.Toxic heavy metals such as lead(Pb),cadmium(Cd),and mercury(Hg)are released during the processing of mining wastewater and leaching of mine tailings.Owing to their excellent physicochemical properties,cementitious materials are widely used for the solidification/stabilization of heavy metals,immobilizing heavy metals via two distinct mechanisms.Physically,their favorable characteristics,including high mechanical strength,low porosity,and durable matrix,create effective barriers.Chemically,the alkaline environment facilitates the precipitation of metal hydroxides/carbonates.Conversely,hydration products(calcium silicate hydrate gels and ettringite)contribute to immobilization through adsorption and physical encapsulation.This study systematically investigated the migration mechanisms of heavy metal contaminants in mine tailings;further,it elucidated the multifaceted immobilization pathways of cementitious materials,which involve synergistic adsorption,precipitation,and encapsulation by hydration products combined with homocrystalline substitution.A comprehensive analysis indicated that cementitious materials significantly reduced the mobility and bioavailability of heavy metals.Nonetheless,their long-term stability and potential environmental impact require further investigation.This study aims to provide theoretical support for environmental management and sustainable resource utilization,and to explore the broader application potential of cementitious technology for heavy metal stabilization,thereby establishing a theoretical foundation for future research on heavy metals in low-cement solidified/stabilized tailings.
基金support from National Key R&D Program of China(2022YFB3807200)Science and Technology Commission of Shanghai Municipality(25CL2902100).
文摘Lithium-rich layered oxides(LRLOs)are promising cathode materials due to their high specific capacity,energy density,and operating voltage.However,their performance is hindered by the limited redox activity of transition metals,leading to oxygen redox instability,oxygen release,and capacity degradation.To address these issues,we propose an innovative lattice-oxygen modulation(LOM)strategy that incorporates Mn^(3+)and Ti^(4+)into the Li_(1.2)Cr_(0.3)Mn_(0.4)Ti_(0.1)O_(2) system,effectively mitigating Cr migration,stabilizing oxygen redox reactions,and reinforcing structural integrity.This results in improved electrochemical performance,as demonstrated by a 56.5 mAh g^(−1) increase in initial discharge capacity to 364.2 mAh g^(−1),with 71.3%capacity retention after 30 cycles,reflecting a 20.2%improvement in cycling stability.Density functional theory(DFT)calculations confirm enhanced Cr redox reversibility and reduced oxygen evolution,further strengthening structural stability.These synergistic effects highlight the pivotal role of the LOM strategy in optimizing both electrochemical performance and structural integrity,offering a scalable pathway to improve capacity and cycling stability in lithium-rich cathodes.
基金supported in part by the National Natural Science Foundation of China(62173208)Taishan Scholar Project of Shandong Province of China(tsqn202103061)the National Science and Technology Council(NSTC),Taiwan,China(NSTC 113-2221-E-006-145-MY2)。
文摘This paper explores the adaptive exponentially designated-time stabilization issue via event-triggered feedback for a kind of uncertain high-order nonlinear systems.The motivation mainly comes from the following two challenges:the undesired singularity problem arising from infinite control gains at the prescribed-time instant,the effective trade-off between the control amplitude and the triggering duration.The goal is to build an event-triggered mechanism comprising a skillful triggered rule alongside a time-dependent threshold.Utilizing the designed control strategy,the solutions'existence and the prevention of Zeno phenomenon are successfully guaranteed by using a new transformation equipped with a time-varying function and redesigning the continuous state-feedback dominance approach with an array of integral functions involving embedded sign functions.Better than existing prescribed-time methods,our approach not only ensures that state variables converge to a small compact set before a designated time and stay there henceforth,and converge to the origin exponentially,but also ensures that the controller continuously works on the whole-time horizon.Two illustrative examples are given to show the effectiveness of the devised scheme.
文摘Unconfined Compressive Strength(UCS)is a key parameter for the assessment of the stability and performance of stabilized soils,yet traditional laboratory testing is both time and resource intensive.In this study,an interpretable machine learning approach to UCS prediction is presented,pairing five models(Random Forest(RF),Gradient Boosting(GB),Extreme Gradient Boosting(XGB),CatBoost,and K-Nearest Neighbors(KNN))with SHapley Additive exPlanations(SHAP)for enhanced interpretability and to guide feature removal.A complete dataset of 12 geotechnical and chemical parameters,i.e.,Atterberg limits,compaction properties,stabilizer chemistry,dosage,curing time,was used to train and test the models.R2,RMSE,MSE,and MAE were used to assess performance.Initial results with all 12 features indicated that boosting-based models(GB,XGB,CatBoost)exhibited the highest predictive accuracy(R^(2)=0.93)with satisfactory generalization on test data,followed by RF and KNN.SHAP analysis consistently picked CaO content,curing time,stabilizer dosage,and compaction parameters as the most important features,aligning with established soil stabilization mechanisms.Models were then re-trained on the top 8 and top 5 SHAP-ranked features.Interestingly,GB,XGB,and CatBoost maintained comparable accuracy with reduced input sets,while RF was moderately sensitive and KNN was somewhat better owing to reduced dimensionality.The findings confirm that feature reduction through SHAP enables cost-effective UCS prediction through the reduction of laboratory test requirements without significant accuracy loss.The suggested hybrid approach offers an explainable,interpretable,and cost-effective tool for geotechnical engineering practice.
基金supported by the Key Research and Development Task Project of Xinjiang Uygur Autonomous Region(No.2022B02033)the National Natural Science Foundation of China(Nos.42211530566 and 42311530066)+2 种基金the NSFC-FNRS Joint Program BIOAGRIFILM(No.FNRS PINT-BILATM 2022)the Science and Technology Project of Bijie Tobacco Company of Guizhou Province(No.2022520500240192)the Agricultural Science and Technology Innovation Program(ASTIP)。
文摘The application of poly(butylene adipate-co-terephthalate)(PBAT)biodegradable plastics has long been constrained by insufficient light aging resistance.Hindered amine light stabilizers(HALSs),known as eco-friendly additives,can scavenge free radicals to enhance polymer durability.However,rough choices have resulted in wastage of resources and environmental pressure.Based on the application of plastic films as the background for use,this study systematically evaluates application effects of five HALSs.The films underwent accelerated aging for various durations and were further investigated by a combination of experiments and molecular simulation.Results showed that all HALSs mitigated PBAT light aging,with Chimassorb-944(UV-944)and Tinuvin-770(UV-770)performing the best for real applications.Quantum chemical calculation results showed that UV-944 had stronger anti migration ability.After 300 h of aging,films with UV-944 and UV-770 retained superior tensile strength and elongation at break in the transverse direction compared to neat PBAT films.Polymeric HALSs provided better long-term stability than small-molecule ones.Further spectra analysis indicated that stronger C―O bonds in HALS/PBAT composites correlated with improved photostability.This study offers valuable insights into improving weather resistance of PBAT biodegradable films and optimizing the real application of HALSs.
基金the National Natural Science Foundation of China (69874008).
文摘The stability and stabilization of a class of linear switched time-varying delay systems are investigated. A piecewise quadratic Lyapunov function （PWQLF） is constructed and is used to obtain the stability conditions based on the linear matrix inequalities （LMIs）. The stabilizing controller for this class of system is then designed and the solution of the desired controller can be obtained by a cone complementary linearization algorithm. Numerical examples are provided to illustrate the less conservativeness of the new stability and the validity of the controller design procedures.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(RS-2024-00455177)the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(RS-2025-00518953)+2 种基金the National Research Council of Science&Technology(NST)grant by the Korea government(MSIT)(GTL24012-000)the support by the National Natural Science Foundation of China(T2322015)the support by The Ministry of Science and ICT in Korea via KBSI(C524100)。
文摘Rechargeable lithium–sulfur(Li–S)batteries are considered promising next-generation energy storage systems owing to their high theoretical energy density,but their application is hindered by the shuttle effect arising from dissolved lithium polysulfides(LiPSs).Herein,we design an optimized electrolyte to achieve long-term stability by employing an appropriate low-polarity solvent.A combination of diethyl ether(DEE)and 1,2-dimethoxyethane(DME)was selected to improve Li metal stability even in the presence of LiPSs.The DEE/DME electrolyte not only suppresses parasitic reactions between Li and LiPSs but also promotes uniform Li deposition.Moreover,operando optical microscopy was employed to directly visualize electrolyte stability and dendrite evolution in real time,while quantitative analysis was conducted via normalized hue index and contour image mapping.The enhanced anode stability of the DEE/DME electrolyte enabled excellent cycling performance,retaining 80.14%of its initial capacity after300 cycles at 3 C,while maintaining superior performance under practical conditions with high sulfur loading and a low E/S ratio.These findings highlight that solvent properties critically influence Li metal stabilization in Li–S batteries and underscore the significance of solvent engineering in electrolyte design.
基金This work was supported by the National Natural Science Foundation of China(No.60275013).
文摘This paper deals with the problem of delay-dependent stability and stabilization for networked control systems(NCSs)with multiple time-delays.In view of multi-input and multi-output(MIMO)NCSs with many independent sensors and actuators,a continuous time model with distributed time-delays is proposed.Utilizing the Lyapunov stability theory combined with linear matrix inequalities(LMIs)techniques,some new delay-dependent stability criteria for NCSs in terms of generalized Lyapunov matrix equation and LMIs are derived.Stabilizing controller via state feedback is formulated by solving a set of LMIs.Compared with the reported methods,the proposed methods give a less conservative delay bound and more general results.Numerical example and simulation show that the methods are less conservative and more effective.
基金Motor Neuron Disease Research Australia in the form of a Bill Gole Postdoctoral Fellowship(PDF2307)FightMND in the form of Drug Development Grants(DDG-159 and DDG137 to JSL)。
文摘Superoxide dismutase 1(SOD1)is a thermodynamically stable,zinc and copper binding homodimeric enzyme responsible for breaking down superoxide radicals.More than 200,mostly missense,mutations spread throughout the SOD1 gene are associated with the fatal neurodegenerative disease,amyotrophic lateral sclerosis(ALS).A unifying feature of ALS-associated SOD1 mutations is the destabilization of the SOD1 protein structure,increasing the propensity for misfolding and subsequent pathological aggregation.Post-mortem analysis of SOD1-associated ALS tissue shows the accumulation of misfolded SOD1 protein and ubiquitinated SOD1 inclusions within motor neurons.Misfolded SOD1 accumulation and aggregates are implicated in cellular dysfunction via a number of disparate but critical processes,including endoplasmic reticulum stress,oxidative damage,proteasome dysfunction,axonal transport abnormalities and synaptic dysfunction;culminating in motor neuron degeneration associated with ALS.
基金supported by National Natural Science Foundation of China (No.60904009,No.60974004)
文摘In this paper, delay-dependent stability analysis and robust stabilization for uncertain singular time-delay systems are addressed. By using Jensen integral inequality, an improved delay-dependent criterion of admissibility for singular time-delay systems is proposed in terms of linear matrix inequality （LMI）. Our new proposed criterion is less conservative and the numerical complexity is smaller than the existing ones. Based on this criterion, a state feedback controller is designed to ensure that the uncertain singular time-delay system is admissible. Finally, three numerical examples are employed to illustrate the effectiveness of the proposed method.
基金the National Natural Science Foundation of China (No.60503027)
文摘This paper investigates the problem of delay-dependent robust stabilization for uncertain singular systems with discrete and distributed delays in terms of linear matrix inequality （LMI） approach. Based on a delay-dependent stability condition for the nominal system, a state feedback controller is designed, which guarantees the resultant closed- loop system to be robustly stable. An explicit expression for the desired controller is also given by solving a set of matrix inequalities. Some numerical examples are provided to illustrate the less conservativeness of the proposed methods.
基金This work was supported by the National Natural Science Foundation of China(No.10571036).
文摘This note deals with the problem of stabilization/stability for neutral systems with nonlinear perturbations. A new stabilization/stability scheme is presented. Using improved Lyapunov functionals, less conservative stabilization/stability conditions are derived for such systems based on linear matrix inequalities （LMI）. Numerical examples are provided to show that the proposed results significantly improve the allowed upper bounds of the delay size over some existing ones in the literature.
基金Project(61273095)supported by the National Natural Science Foundation of ChinaProject(135225)supported by the Academy of Finland
文摘To alleviate the conservativeness of the stability criterion for Takagi-Sugeno （T-S） fuzzy time-delay systems, a new delay-dependent stability criterion was proposed by introducing a new augmented Lyapunov function with an additional triple-integral term, which was firstly u3ed to derive the stability criterion for T-S fuzzy time-delay systems. By the same approach, the robust stability issue for fuzzy time-delay systems with uncertain parameters was also considered. On the other hand, in order to enhance the design flexibility, a new design approach for uncertain fuzzy time-delay systems under imperfect premise matching was also proposed, which allows the fuzzy controller to employ different membership functions from the fuzzy time-delay model. By the numerical examples, the proposed stability conditions are less conservative in the sense of getting larger allowable time-delay and obtaining smaller feedback control gains. For instance, when the allowable time-delay increases from 7.3 s to 12 s for an uncertain T-S fuzzy control system with time-delay, the norm of the feedback gains decreases from （34.299 2, 38.560 3） to （10.073 3, 11.349 0）, respectively. Meanwhile, the effectiveness of the proposed design method was illustrated by the last example with the robustly stable curves of system state under the initial condition of x（0） = [3 -1].
