Liver transplantation(LT)remains the optimal life-saving intervention for patients with end-stage liver disease.Despite the recent advances in LT several barriers,including organ allocation,donor-recipient matching,an...Liver transplantation(LT)remains the optimal life-saving intervention for patients with end-stage liver disease.Despite the recent advances in LT several barriers,including organ allocation,donor-recipient matching,and patient education,persist.With the growing progress of artificial intelligence,particularly large language models(LLMs)like ChatGPT,new applications have emerged in the field of LT.Current studies demonstrating usage of ChatGPT in LT include various areas of application,from clinical settings to research and education.ChatGPT usage can benefit both healthcare professionals,by decreasing the time spent on non-clinical work,but also LT recipients by providing accurate information.Future potential applications include the expanding usage of ChatGPT and other LLMs in the field of LT pathology and radiology as well as the automated creation of discharge summaries or other related paperwork.Additionally,the next models of ChatGPT might have the potential to provide more accurate patient education material with increased readability.Although ChatGPT usage presents promising applications,there are certain ethical and practical limitations.Key concerns include patient data privacy,information accuracy,misinformation possibility and lack of legal framework.Healthcare providers and policymakers should collaborate for the establishment of a controlled framework for the safe use of ChatGPT.The aim of this minireview is to summarize current literature on ChatGPT in LT,highlighting both opportunities and limitations,while also providing future possible applications.展开更多
In this paper, the Melnikov function method has been used to analyse the distance between stable manifold and unstable manifold of the soft spring Duffing equation([1]) after its heteroclinic orbits rupture as the res...In this paper, the Melnikov function method has been used to analyse the distance between stable manifold and unstable manifold of the soft spring Duffing equation([1]) after its heteroclinic orbits rupture as the result of a small perturbation. The conditions that limit circles are bifurcated are given, and then their stability and location is determined.展开更多
This paper deals with the monotonicity of limit wave speed c0(h)to a perturbed g KdV equation.We show the decrease of c0(h)by combining the analytic method and the numerical technique.Our results solve a special case ...This paper deals with the monotonicity of limit wave speed c0(h)to a perturbed g KdV equation.We show the decrease of c0(h)by combining the analytic method and the numerical technique.Our results solve a special case of the open question presented by Yan et al.,and the method potentially provides a way to study the monotonicity of c0(h)for general m∈N^(+).展开更多
This article examines the influence of annealing temperature on fracture toughness and forming limit curves of dissimilar aluminum/silver sheets.In the cold roll bonding process,after brushing and acid washing,the pre...This article examines the influence of annealing temperature on fracture toughness and forming limit curves of dissimilar aluminum/silver sheets.In the cold roll bonding process,after brushing and acid washing,the prepared surfaces are placed on top of each other and by rolling with reduction more than 50%,the bonding between layers is established.In this research,the roll bonding process was done at room temperature,without the use of lubricants and with a 70%thickness reduction.Then,the final thickness of the Ag/Al bilayer sheet reached 350μm by several stages of cold rolling.Before cold rolling,it should be noted that to decrease the hardness created due to plastic deformation,the roll-bonded samples were subjected to annealing heat treatment at 400℃for 90 min.Thus,the final samples were annealed at 200,300 and 400℃for 90 min and cooled in a furnace to examine the annealing temperature effects.The uniaxial tensile and microhardness tests measured mechanical properties.Also,to investigate the fracture mechanism,the fractography of the cross-section was examined by scanning electron microscope(SEM).To evaluate the formability of Ag/Al bilayer sheets,forming limit curves were obtained experimentally through the Nakazima test.The resistance of composites to failure due to cracking was also investigated by fracture toughness.The results showed that annealing increases the elongation and formability of the Ag/Al bilayer sheet while reduces the ultimate tensile strength and fracture toughness.However,the changing trend is not the same at different temperatures,and according to the results,the most significant effect is obtained at 300℃and aluminum layers.It was also determined that by increasing annealing temperature,the fracture mechanism from shear ductile with small and shallow dimples becomes ductile with deep cavities.展开更多
In this paper,we study the following pseudo-relativistic Hartree equation i∂_(t)Ψ-(|x|^(-1)*|Ψ|^(2))Ψwith(t,x)∈R×R^(3)We mainly focus on the normalized ground state solitary waves of the formΨ(t,x)=e^(itμ)...In this paper,we study the following pseudo-relativistic Hartree equation i∂_(t)Ψ-(|x|^(-1)*|Ψ|^(2))Ψwith(t,x)∈R×R^(3)We mainly focus on the normalized ground state solitary waves of the formΨ(t,x)=e^(itμ)φm(x)with||φm||_(2)^(2)=N.We investigate limit behaviors of energy and minimizer of the corresponding frinetional of this equationas m→+∞.We prove that m_(k)^(-3/2)φm_(k)→φ∞(x)in H^(-1/2(R^(3)))by energy method and lim_(m→+∞)+m^(-1)e(N)=e(N),whereφ_(m)(β∞)is a minimizer of e(N)(e(N).展开更多
The paper considers the methodology for a comprehensive analysis of the stability of an open pit-dump system,using limit equilibrium(LEM)and finite element(FEM)methods in the Russian CAE(computer-aided engineering)sof...The paper considers the methodology for a comprehensive analysis of the stability of an open pit-dump system,using limit equilibrium(LEM)and finite element(FEM)methods in the Russian CAE(computer-aided engineering)software Fidesys.It briefly highlights the issues of comparing limit equilibrium methods using the VNIMI(Research Institute of Geomechanics and Mine Surveying-Intersectoral Scientific Center"VNIMI")methodology and a specialized software product with numerical methods.The main focus of this study is to compare the results of the stability analysis in the volumetric model of the open pit-dump system using limit equilibrium and finite element methods in the CAE software Fidesys.It was found that,when modeling the combined operation of an open pit-dump system in complex terrain,both methods should be used,as each has its own advantages.The finite element method,for instance,has certain features that are not present in the calculations using the limit equilibrium approach.As a key scientific contribution,this paper introduces an automation program for calculating the stability of open-pit walls using the limit equilibrium method in CAE Fidesys,which was not previously integrated in the original software.The calculations performed with the use of this newly developed module were compared to those obtained from other widely used software solutions available on the market.The findings demonstrate a remarkable level of convergence in the calculation results for all relevant parameters,including the safety factor,localization,instability type,and deformation.The proposed approach i mproves the accuracy of calculati ons and ensures consistency between the higher stress design zones and the actual deformation and fracture patterns.It also enhances the ability to predict the behavior of rock mass when calculating stability parameters for facilities,both during operation and desi gn.展开更多
In this paper,a nonlinear control approach for an unstable networked plant in the presence of actuator and sensor limitations using robust right coprime factorization is proposed.The actuator is limited by upper and l...In this paper,a nonlinear control approach for an unstable networked plant in the presence of actuator and sensor limitations using robust right coprime factorization is proposed.The actuator is limited by upper and lower constraints and the sensor in the feedback loop is subjected to network-induced unknown time-varying delay and noise.With this nonlinear control method,we first employ right coprime factorization based on isomorphism and operator theory to factorize the plant,so that bounded input bounded output(BIBO)stability can be guaranteed.Next,continuous-time generalized predictive control(CGPC)is utilized for the unstable operator of the right coprime factorized plant to guarantee inner stability and enables the closed-loop dynamics of the system with predictive characteristics.Meanwhile,a second-Do F(degrees of freedom)switched controller that satisfies a perturbed Bezout identity and a robustness condition is designed.By using the CGPC controller that possesses predictive behavior and the second-Do F switched stabilizer,the overall stability of the plant subjected to actuator limitations is guaranteed.To address sensor limitations that exist in networked plants in the form of delay and noise which often cause system performance degradation,we implement an identity operator definition in the feedback loop to compensate for these adverse effects.Further,a pre-operator is designed to ensure that the plant output tracks the reference input.Finally,the effectiveness of the proposed design scheme is demonstrated by simulations.展开更多
Recently,information acquired at the canopy top,such as spectral and textural data,has been widely used to estimate plant nitrogen(N)accumulation(PNA).The response of crops to N uptake involves not only changes in hor...Recently,information acquired at the canopy top,such as spectral and textural data,has been widely used to estimate plant nitrogen(N)accumulation(PNA).The response of crops to N uptake involves not only changes in horizontal canopy top information but also an increase in vertical plant height(PH).It remains unclear whether the fusion of spectral indices with PH can improve the estimation performance of PNA models based on spectral remote sensing across different growth stages.展开更多
Objective:To evaluate the effectiveness of the internal limiting membrane(ILM)flipping and covering technique in the treatment of patients with high myopic macular hole(HMMH).Methods:One hundred and two patients with ...Objective:To evaluate the effectiveness of the internal limiting membrane(ILM)flipping and covering technique in the treatment of patients with high myopic macular hole(HMMH).Methods:One hundred and two patients with HMMH who were admitted to the hospital from June 2019 to June 2024 were selected.The minimum diameter of the macular hole(MH)in all patients was≤500μm.The patients were randomly divided into two groups.The experimental group received 25G pars plana vitrectomy(PPV)combined with ILM flipping and covering technique,while the reference group received PPV combined with ILM peeling.The efficacy indicators and best corrected visual acuity levels were compared between the two groups.Results:The MH closure rate and retinal reattachment rate were higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).The best corrected visual acuity level was higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).The Chinese version of the Visual Function-Related Quality of Life Questionnaire-25(CVRQOL-25)score was higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).No serious complications were observed in both groups postoperatively,and there was no difference between the two groups(P>0.05).Conclusion:The ILM flipping and covering technique can improve the MH closure rate and retinal reattachment rate in patients with HMMH(diameter≤500μm),enhance the best corrected visual acuity level,and improve the quality of life related to visual function,with fewer postoperative complications.展开更多
Silicon limitation negatively affects the growth and metabolism of diatoms.However,its influence on the topography and mechanical properties of diatom frustules,and consequently on predation,remains unclear.We investi...Silicon limitation negatively affects the growth and metabolism of diatoms.However,its influence on the topography and mechanical properties of diatom frustules,and consequently on predation,remains unclear.We investigated how silicon limitation affects the mechanical strength of diatom frustules.Under silicon limitation,the growth rates of diatom Cylindrotheca closterium,Amphora coffeaeformis,Thalassiosira weissflogii,and Cyclotella sp.decreased by 19%,56%,42%,and 73%,respectively.Similarly,the biogenic silica content of silicon-limited C.closterium,T.weissflogii,and Cyclotella sp.decreased by 17%,11%,and 9%,respectively,whereas A.coffeaeformis showed a 63%increase.Atomic force microscopy and X-ray photoelectron spectroscopy revealed that silicon shortage reduced frustule hardness by approximately 60%and decreased condensed silica components on their surface by about 80%,except in A.coffeaeformis.Additionally,copepods consumed 20%to 600%more diatoms grown under silicon deficiency compared to those grown under Si-rich conditions,with the exception of A.coffeaeformis.These findings suggest that silicon limitation diminishes diatom populations and accelerates carbon export from diatoms to the deep sea.展开更多
As a new dynamic reactive power compensator,the grid-forming Static Var Generator(GF-SVG)can not only provide reactive power-voltage support,but also has inertial support capability.It has been experimentally deployed...As a new dynamic reactive power compensator,the grid-forming Static Var Generator(GF-SVG)can not only provide reactive power-voltage support,but also has inertial support capability.It has been experimentally deployed in many wind farms.However,studies have shown that when the three-phase short-circuit fault occurs in the wind farm,the transient overcurrent during the fault occurrence and fault clearance is suppressed,making it difficult for GF-SVG to use traditional fixed virtual impedance.Aiming at the problem,firstly,the influence of virtual reactance on control stability is analyzed using the GF-SVG’s current open-loop transfer function.Secondly,based on the existing current limitation strategies of GF-SVG,an adaptive virtual reactance current limitation strategy suitable for symmetrical faults of the power grid is proposed,which limits GF-SVG’s transient overcurrent during fault occurrence and fault clearance stage to the tolerance range of GF-SVG’s power devices.Based on the GF-SVG’s active power loop and reactive power loop small signal models,the availability of the proposed adaptive virtual reactance in suppressing the DC voltage drop of GF-SVG is analyzed,and shortening the transient overvoltage recovery time of the wind farm after the fault clearance is also discussed.Finally,electromagnetic simulation proves the effectiveness and correctness of the proposed adaptive current limitation method.展开更多
Optical monitoring of object position and alignment with nanoscale precision is critical for ultra-precision measurement applications,such as micro/nano-fabrication,weak force sensing,and micro-scopic imaging.Traditio...Optical monitoring of object position and alignment with nanoscale precision is critical for ultra-precision measurement applications,such as micro/nano-fabrication,weak force sensing,and micro-scopic imaging.Traditional optical nanometry methods often rely on precision nanostructure fabrication,multi-beam interferometry,or complex post-processing algorithms,which can limit their practical use.In this study,we introduced a simplified and robust quantum measurement technique with an achievable resolution of 2.2 pm and an experimental demonstration of 1 nm resolution,distinguishing it from conventional interferometry,which depended on multiple reference beams.We designed a metasurface substrate with a mode-conversion function,in which an incident Gaussian beam is converted into higher-order transverse electromagnetic mode(TEM)modes.A theoretical analysis,including calculations of the Fisher information,demonstrated that the accuracy was maintained for nanoscale displacements.In conclusion,the study findings provide a new approach for precise alignment and metrology of nanofabrication and other advanced applications.展开更多
We investigate the vanishing viscosity limit of a parabolic-elliptic coupled system arising in radiation hydrodynamics.The limit is the solution to a hyperbolic-elliptic coupled system.We study the problem on both the...We investigate the vanishing viscosity limit of a parabolic-elliptic coupled system arising in radiation hydrodynamics.The limit is the solution to a hyperbolic-elliptic coupled system.We study the problem on both the whole line R and the half line R_+.Two types of conditions are considered:(1)the initial data are sufficiently close to a given initial state with small wave strength,and(2)the initial data are monotonically increasing.Under these conditions,we establish uniform convergence rates for both Cauchy problems and initial-boundary value problems.Specifically,we demonstrate that the solutions to the parabolic-elliptic system converge to those of the hyperbolic-elliptic system as the viscosity coefficientεapproaches zero,with convergence rates of O(ε^(3/4))for u and O(ε)for q in L^(∞)-norm.Additionally,we prove the global well-posedness of the parabolic-elliptic coupled system by the maximum principle and energy method.Our results extend previous work by providing explicit convergence rates and addressing both Cauchy problems and initial-boundary value problems under various conditions.展开更多
Predictive control(PC)is an advanced control algorithm,which is widely used in industrial process control.Among them,model-based predictive control(MPC)is an important branch of predictive control.Its basic principle ...Predictive control(PC)is an advanced control algorithm,which is widely used in industrial process control.Among them,model-based predictive control(MPC)is an important branch of predictive control.Its basic principle is to use the system model to predict future behavior and determine the current control action by optimizing the objective function.Based on the algorithm combined with three different sections using deep learning technology to identify vehicles and output the optimal speed limit,to achieve the effect of traffic flow optimization.展开更多
Commonly,the standards for the geometric design of roads refer to a given set of values for the friction coefficient(longitudinal and transverse friction).These"reference"values imply corresponding visibilit...Commonly,the standards for the geometric design of roads refer to a given set of values for the friction coefficient(longitudinal and transverse friction).These"reference"values imply corresponding visibility sights,curvature radii,and speed limits.Unfortunately,not only do these reference values not correspond to a given standard to measure them,but nothing is said about the decrease of the posted speed limit(variable speed limits)when roads become slippery and lanes for autonomous vehicle(AV)are concerned.Furthermore,the same assessment of the friction coefficient has plenty of uncertainties due to measurement device,temperature,location,time passed from the construction,alignment-related variables(e.g.,curve,tangent,transition curve,convexity/crests or concavity/sags,longitudinal slope,superelevation,and ruling gradient),and supplementary singularities such as joints and bridge approaches.All the issues above may harm road safety and the complexity of forensic investigations of pavements.Consequently,this study's objectives were confined to(1)carrying out friction measurements and analyzing the problem of friction decay over time;(2)setting up a method to lower the speed limits where friction decays are detected;(3)setting up a method to handle friction decays for autonomous vehicles.Results demonstrate that:(1)a power law describes how the speed limits are affected by friction;(2)for speeds up to 170 km/h,due to the lower reaction time,AV reaction distance is lower,which benefits AV traffic(lower stopping distance);(3)on the contrary,for higher values of friction and higher speeds,under the hypothesis of having the same reaction time law for non-AV(NAV)(i.e.,decreasing with the initial speed),AV speed limits become lower than NAV speed limits;(4)not only do comfort-based speed profiles for AVs bring higher braking distances,but also,in the median part(of the deceleration process),this could pose safety issues and reduce the distance between the available and the needed friction.展开更多
The reignition of aero-engine combustors at high altitudes poses significant challenges due to the low-temperature and low-pressure environment.A novel Long Pulse-Width Plasma Ignition(LPWPI)system has been developed ...The reignition of aero-engine combustors at high altitudes poses significant challenges due to the low-temperature and low-pressure environment.A novel Long Pulse-Width Plasma Ignition(LPWPI)system has been developed to enhance ignition performance.The LPWPI system can effectively prolong the discharge duration time,improve ignition efficacy,and increase the plasma penetration depth.Experimental comparisons with the traditional Spark Ignition(SI)system demonstrate that the LPWPI increased discharge duration to 2.03 ms,which is 45 times longer than that of the SI system,while also doubling the spark penetration depth to 24.1 mm.The LPWPI system achieved a discharge efficiency of 61.1%,significantly surpassing the SI system's efficiency of23.3%.These advancements facilitated an extension of the lean ignition boundary by approximately 22.7%to 39.3%.High-speed camera recordings reveal that the spark duration of the LPWPI system was extended to 2.1 ms,compared to 0.6 ms in the SI system.Ignition progress with LPWPI shows a sustained spark kernel without the flame residence stage observed in the SI system.The impressive performance of the LPWPI system suggests that it is a promising alternative for aero-engine ignition systems.展开更多
Channel state information(CSI)is essen-tial to unlock the potential of reconfigurable intelli-gent surfaces(RISs)in wireless communication sys-tems.Since massive RIS elements are typically imple-mented without baseban...Channel state information(CSI)is essen-tial to unlock the potential of reconfigurable intelli-gent surfaces(RISs)in wireless communication sys-tems.Since massive RIS elements are typically imple-mented without baseband signal processing capabili-ties,limited CSI feedback is necessary when design-ing the reflection/refraction coefficients of the RIS.In this article,the unique RIS-assisted channel features,such as the RIS position-dependent channel fluctua-tion,the ultra-high dimensional sub-channel matrix,and the structured sparsity,are distilled from recent advances in limited feedback and used as guidelines for designing feedback schemes.We begin by il-lustrating the use cases and the corresponding chal-lenges associated with RIS feedback.We then discuss how to leverage techniques such as channel customiza-tion,structured-sparsity,autoencoders,and others to reduce feedback overhead and complexity when de-vising feedback schemes.Finally,we identify poten-tial research directions by considering the unresolved challenges,the new RIS architecture,and the integra-tion with multi-modal information and artificial intel-ligence.展开更多
Application of variable speed limits(VSL)is gradually increasingly implemented especially on highways.As a result of conducted studies and implementations,it is observed that the variable speed limits have reduced the...Application of variable speed limits(VSL)is gradually increasingly implemented especially on highways.As a result of conducted studies and implementations,it is observed that the variable speed limits have reduced the number of car accidents as well as proved positive results in terms of delays and environmental factors.Purpose of this study is to develop an algorithm for VSL application that is considered to be applied on Istanbul D100 highway and to assess the effects of application.Algorithm that is developed for VSL is a different VSL algorithm and compared with the constant speed system.According to obtained results,when the proposed system is compared to current system,it is observed that the number of delays and average stops are reduced%30 and%40 respectively and also emissions reduced at the rate of%12.展开更多
On July 24th, Lectra's Board of Directors, chaired by Daniel Harari, reviewed the consolidated financial statements for the first half of 2025, which have been subject to a limited review by the Statutory Auditors.
In this paper,we investigate the propagation of chaos for solutions to the Liouville equation derived from the Linear-Formation particle model.By imposing certain conditions,we derive the rate of convergence between t...In this paper,we investigate the propagation of chaos for solutions to the Liouville equation derived from the Linear-Formation particle model.By imposing certain conditions,we derive the rate of convergence between the k-tensor product f_(t)^(■k)of the solution to be Linear-Formation kinetic equation and the k-marginal f_(N,k)^(t)of the solution to the Liouville equation corresponding to the Linear-Formation particle model.Specifically,the following estimate holds in terms of p-Wasserstein(1≤p<∞)distance W_(p)^(p)(f_(t)^(■k),f_(N,k)^(t))≤C_(1)k/N^(min(p/2,1))(1+t^(p))e^(C_(2)^(t)),1≤k≤N.展开更多
文摘Liver transplantation(LT)remains the optimal life-saving intervention for patients with end-stage liver disease.Despite the recent advances in LT several barriers,including organ allocation,donor-recipient matching,and patient education,persist.With the growing progress of artificial intelligence,particularly large language models(LLMs)like ChatGPT,new applications have emerged in the field of LT.Current studies demonstrating usage of ChatGPT in LT include various areas of application,from clinical settings to research and education.ChatGPT usage can benefit both healthcare professionals,by decreasing the time spent on non-clinical work,but also LT recipients by providing accurate information.Future potential applications include the expanding usage of ChatGPT and other LLMs in the field of LT pathology and radiology as well as the automated creation of discharge summaries or other related paperwork.Additionally,the next models of ChatGPT might have the potential to provide more accurate patient education material with increased readability.Although ChatGPT usage presents promising applications,there are certain ethical and practical limitations.Key concerns include patient data privacy,information accuracy,misinformation possibility and lack of legal framework.Healthcare providers and policymakers should collaborate for the establishment of a controlled framework for the safe use of ChatGPT.The aim of this minireview is to summarize current literature on ChatGPT in LT,highlighting both opportunities and limitations,while also providing future possible applications.
文摘In this paper, the Melnikov function method has been used to analyse the distance between stable manifold and unstable manifold of the soft spring Duffing equation([1]) after its heteroclinic orbits rupture as the result of a small perturbation. The conditions that limit circles are bifurcated are given, and then their stability and location is determined.
基金Supported by the National Natural Science Foundation of China(12071162)the Natural Science Foundation of Fujian Province(2021J01302)the Fundamental Research Funds for the Central Universities(ZQN-802)。
文摘This paper deals with the monotonicity of limit wave speed c0(h)to a perturbed g KdV equation.We show the decrease of c0(h)by combining the analytic method and the numerical technique.Our results solve a special case of the open question presented by Yan et al.,and the method potentially provides a way to study the monotonicity of c0(h)for general m∈N^(+).
基金Project(4013311)supported by the National Science Foundation of Iran(INSF)。
文摘This article examines the influence of annealing temperature on fracture toughness and forming limit curves of dissimilar aluminum/silver sheets.In the cold roll bonding process,after brushing and acid washing,the prepared surfaces are placed on top of each other and by rolling with reduction more than 50%,the bonding between layers is established.In this research,the roll bonding process was done at room temperature,without the use of lubricants and with a 70%thickness reduction.Then,the final thickness of the Ag/Al bilayer sheet reached 350μm by several stages of cold rolling.Before cold rolling,it should be noted that to decrease the hardness created due to plastic deformation,the roll-bonded samples were subjected to annealing heat treatment at 400℃for 90 min.Thus,the final samples were annealed at 200,300 and 400℃for 90 min and cooled in a furnace to examine the annealing temperature effects.The uniaxial tensile and microhardness tests measured mechanical properties.Also,to investigate the fracture mechanism,the fractography of the cross-section was examined by scanning electron microscope(SEM).To evaluate the formability of Ag/Al bilayer sheets,forming limit curves were obtained experimentally through the Nakazima test.The resistance of composites to failure due to cracking was also investigated by fracture toughness.The results showed that annealing increases the elongation and formability of the Ag/Al bilayer sheet while reduces the ultimate tensile strength and fracture toughness.However,the changing trend is not the same at different temperatures,and according to the results,the most significant effect is obtained at 300℃and aluminum layers.It was also determined that by increasing annealing temperature,the fracture mechanism from shear ductile with small and shallow dimples becomes ductile with deep cavities.
文摘In this paper,we study the following pseudo-relativistic Hartree equation i∂_(t)Ψ-(|x|^(-1)*|Ψ|^(2))Ψwith(t,x)∈R×R^(3)We mainly focus on the normalized ground state solitary waves of the formΨ(t,x)=e^(itμ)φm(x)with||φm||_(2)^(2)=N.We investigate limit behaviors of energy and minimizer of the corresponding frinetional of this equationas m→+∞.We prove that m_(k)^(-3/2)φm_(k)→φ∞(x)in H^(-1/2(R^(3)))by energy method and lim_(m→+∞)+m^(-1)e(N)=e(N),whereφ_(m)(β∞)is a minimizer of e(N)(e(N).
文摘The paper considers the methodology for a comprehensive analysis of the stability of an open pit-dump system,using limit equilibrium(LEM)and finite element(FEM)methods in the Russian CAE(computer-aided engineering)software Fidesys.It briefly highlights the issues of comparing limit equilibrium methods using the VNIMI(Research Institute of Geomechanics and Mine Surveying-Intersectoral Scientific Center"VNIMI")methodology and a specialized software product with numerical methods.The main focus of this study is to compare the results of the stability analysis in the volumetric model of the open pit-dump system using limit equilibrium and finite element methods in the CAE software Fidesys.It was found that,when modeling the combined operation of an open pit-dump system in complex terrain,both methods should be used,as each has its own advantages.The finite element method,for instance,has certain features that are not present in the calculations using the limit equilibrium approach.As a key scientific contribution,this paper introduces an automation program for calculating the stability of open-pit walls using the limit equilibrium method in CAE Fidesys,which was not previously integrated in the original software.The calculations performed with the use of this newly developed module were compared to those obtained from other widely used software solutions available on the market.The findings demonstrate a remarkable level of convergence in the calculation results for all relevant parameters,including the safety factor,localization,instability type,and deformation.The proposed approach i mproves the accuracy of calculati ons and ensures consistency between the higher stress design zones and the actual deformation and fracture patterns.It also enhances the ability to predict the behavior of rock mass when calculating stability parameters for facilities,both during operation and desi gn.
文摘In this paper,a nonlinear control approach for an unstable networked plant in the presence of actuator and sensor limitations using robust right coprime factorization is proposed.The actuator is limited by upper and lower constraints and the sensor in the feedback loop is subjected to network-induced unknown time-varying delay and noise.With this nonlinear control method,we first employ right coprime factorization based on isomorphism and operator theory to factorize the plant,so that bounded input bounded output(BIBO)stability can be guaranteed.Next,continuous-time generalized predictive control(CGPC)is utilized for the unstable operator of the right coprime factorized plant to guarantee inner stability and enables the closed-loop dynamics of the system with predictive characteristics.Meanwhile,a second-Do F(degrees of freedom)switched controller that satisfies a perturbed Bezout identity and a robustness condition is designed.By using the CGPC controller that possesses predictive behavior and the second-Do F switched stabilizer,the overall stability of the plant subjected to actuator limitations is guaranteed.To address sensor limitations that exist in networked plants in the form of delay and noise which often cause system performance degradation,we implement an identity operator definition in the feedback loop to compensate for these adverse effects.Further,a pre-operator is designed to ensure that the plant output tracks the reference input.Finally,the effectiveness of the proposed design scheme is demonstrated by simulations.
基金supported by the National Key Research and Development Plan Project Sub-Topic of China(Grant Nos.2022YFD1901500 and 2022YFD1901505-07)the National Natural Science Foundation of China(Grant No.32260531)+1 种基金the Key Laboratory of Molecular Breeding for Grain and Oil Crops in Guizhou Province,China(Grant No.Qiankehezhongyindi[2023]8)the Key Laboratory of Functional Agriculture of Guizhou Provincial Higher Education Institutions,China(Grant No.Qianjiaoji[2023]007).
文摘Recently,information acquired at the canopy top,such as spectral and textural data,has been widely used to estimate plant nitrogen(N)accumulation(PNA).The response of crops to N uptake involves not only changes in horizontal canopy top information but also an increase in vertical plant height(PH).It remains unclear whether the fusion of spectral indices with PH can improve the estimation performance of PNA models based on spectral remote sensing across different growth stages.
文摘Objective:To evaluate the effectiveness of the internal limiting membrane(ILM)flipping and covering technique in the treatment of patients with high myopic macular hole(HMMH).Methods:One hundred and two patients with HMMH who were admitted to the hospital from June 2019 to June 2024 were selected.The minimum diameter of the macular hole(MH)in all patients was≤500μm.The patients were randomly divided into two groups.The experimental group received 25G pars plana vitrectomy(PPV)combined with ILM flipping and covering technique,while the reference group received PPV combined with ILM peeling.The efficacy indicators and best corrected visual acuity levels were compared between the two groups.Results:The MH closure rate and retinal reattachment rate were higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).The best corrected visual acuity level was higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).The Chinese version of the Visual Function-Related Quality of Life Questionnaire-25(CVRQOL-25)score was higher in the experimental group than in the reference group at 3 and 6 months postoperatively(P<0.05).No serious complications were observed in both groups postoperatively,and there was no difference between the two groups(P>0.05).Conclusion:The ILM flipping and covering technique can improve the MH closure rate and retinal reattachment rate in patients with HMMH(diameter≤500μm),enhance the best corrected visual acuity level,and improve the quality of life related to visual function,with fewer postoperative complications.
基金Supported by the National Natural Science Foundation of China(Nos.U 23 A 2048,42376152,42076148)the Special Program of Key Sectors in Guangdong Universities(Nos.2022 ZDZX 4040,2023 KCXTD 028)。
文摘Silicon limitation negatively affects the growth and metabolism of diatoms.However,its influence on the topography and mechanical properties of diatom frustules,and consequently on predation,remains unclear.We investigated how silicon limitation affects the mechanical strength of diatom frustules.Under silicon limitation,the growth rates of diatom Cylindrotheca closterium,Amphora coffeaeformis,Thalassiosira weissflogii,and Cyclotella sp.decreased by 19%,56%,42%,and 73%,respectively.Similarly,the biogenic silica content of silicon-limited C.closterium,T.weissflogii,and Cyclotella sp.decreased by 17%,11%,and 9%,respectively,whereas A.coffeaeformis showed a 63%increase.Atomic force microscopy and X-ray photoelectron spectroscopy revealed that silicon shortage reduced frustule hardness by approximately 60%and decreased condensed silica components on their surface by about 80%,except in A.coffeaeformis.Additionally,copepods consumed 20%to 600%more diatoms grown under silicon deficiency compared to those grown under Si-rich conditions,with the exception of A.coffeaeformis.These findings suggest that silicon limitation diminishes diatom populations and accelerates carbon export from diatoms to the deep sea.
基金supported by the National Natural Science Foundation of China under Grant 52077030.
文摘As a new dynamic reactive power compensator,the grid-forming Static Var Generator(GF-SVG)can not only provide reactive power-voltage support,but also has inertial support capability.It has been experimentally deployed in many wind farms.However,studies have shown that when the three-phase short-circuit fault occurs in the wind farm,the transient overcurrent during the fault occurrence and fault clearance is suppressed,making it difficult for GF-SVG to use traditional fixed virtual impedance.Aiming at the problem,firstly,the influence of virtual reactance on control stability is analyzed using the GF-SVG’s current open-loop transfer function.Secondly,based on the existing current limitation strategies of GF-SVG,an adaptive virtual reactance current limitation strategy suitable for symmetrical faults of the power grid is proposed,which limits GF-SVG’s transient overcurrent during fault occurrence and fault clearance stage to the tolerance range of GF-SVG’s power devices.Based on the GF-SVG’s active power loop and reactive power loop small signal models,the availability of the proposed adaptive virtual reactance in suppressing the DC voltage drop of GF-SVG is analyzed,and shortening the transient overvoltage recovery time of the wind farm after the fault clearance is also discussed.Finally,electromagnetic simulation proves the effectiveness and correctness of the proposed adaptive current limitation method.
基金supported by the West Light Project,CAS(xbzg-zdsys-202206)the National Key Research and Development Program of China(2021YFA1401003)+1 种基金the National Natural Science Foundation of China(NSFC)(62222513,U24A6010,and U24A20317)the Sichuan Engineering Research Center of Digital Materials.
文摘Optical monitoring of object position and alignment with nanoscale precision is critical for ultra-precision measurement applications,such as micro/nano-fabrication,weak force sensing,and micro-scopic imaging.Traditional optical nanometry methods often rely on precision nanostructure fabrication,multi-beam interferometry,or complex post-processing algorithms,which can limit their practical use.In this study,we introduced a simplified and robust quantum measurement technique with an achievable resolution of 2.2 pm and an experimental demonstration of 1 nm resolution,distinguishing it from conventional interferometry,which depended on multiple reference beams.We designed a metasurface substrate with a mode-conversion function,in which an incident Gaussian beam is converted into higher-order transverse electromagnetic mode(TEM)modes.A theoretical analysis,including calculations of the Fisher information,demonstrated that the accuracy was maintained for nanoscale displacements.In conclusion,the study findings provide a new approach for precise alignment and metrology of nanofabrication and other advanced applications.
基金supported by the Guangdong Basic and Applied Basic Research Foundation(2024A1515012340)the NSFC(12571233,12171160)。
文摘We investigate the vanishing viscosity limit of a parabolic-elliptic coupled system arising in radiation hydrodynamics.The limit is the solution to a hyperbolic-elliptic coupled system.We study the problem on both the whole line R and the half line R_+.Two types of conditions are considered:(1)the initial data are sufficiently close to a given initial state with small wave strength,and(2)the initial data are monotonically increasing.Under these conditions,we establish uniform convergence rates for both Cauchy problems and initial-boundary value problems.Specifically,we demonstrate that the solutions to the parabolic-elliptic system converge to those of the hyperbolic-elliptic system as the viscosity coefficientεapproaches zero,with convergence rates of O(ε^(3/4))for u and O(ε)for q in L^(∞)-norm.Additionally,we prove the global well-posedness of the parabolic-elliptic coupled system by the maximum principle and energy method.Our results extend previous work by providing explicit convergence rates and addressing both Cauchy problems and initial-boundary value problems under various conditions.
文摘Predictive control(PC)is an advanced control algorithm,which is widely used in industrial process control.Among them,model-based predictive control(MPC)is an important branch of predictive control.Its basic principle is to use the system model to predict future behavior and determine the current control action by optimizing the objective function.Based on the algorithm combined with three different sections using deep learning technology to identify vehicles and output the optimal speed limit,to achieve the effect of traffic flow optimization.
文摘Commonly,the standards for the geometric design of roads refer to a given set of values for the friction coefficient(longitudinal and transverse friction).These"reference"values imply corresponding visibility sights,curvature radii,and speed limits.Unfortunately,not only do these reference values not correspond to a given standard to measure them,but nothing is said about the decrease of the posted speed limit(variable speed limits)when roads become slippery and lanes for autonomous vehicle(AV)are concerned.Furthermore,the same assessment of the friction coefficient has plenty of uncertainties due to measurement device,temperature,location,time passed from the construction,alignment-related variables(e.g.,curve,tangent,transition curve,convexity/crests or concavity/sags,longitudinal slope,superelevation,and ruling gradient),and supplementary singularities such as joints and bridge approaches.All the issues above may harm road safety and the complexity of forensic investigations of pavements.Consequently,this study's objectives were confined to(1)carrying out friction measurements and analyzing the problem of friction decay over time;(2)setting up a method to lower the speed limits where friction decays are detected;(3)setting up a method to handle friction decays for autonomous vehicles.Results demonstrate that:(1)a power law describes how the speed limits are affected by friction;(2)for speeds up to 170 km/h,due to the lower reaction time,AV reaction distance is lower,which benefits AV traffic(lower stopping distance);(3)on the contrary,for higher values of friction and higher speeds,under the hypothesis of having the same reaction time law for non-AV(NAV)(i.e.,decreasing with the initial speed),AV speed limits become lower than NAV speed limits;(4)not only do comfort-based speed profiles for AVs bring higher braking distances,but also,in the median part(of the deceleration process),this could pose safety issues and reduce the distance between the available and the needed friction.
基金co-supported by the National Natural Science Foundation of China(Nos.52376138 and 52025064)the Science Center for Gas Turbine Project,China(No.P2022B-Ⅱ-018-001)the Foundation Research Project,China(No.1002TJA22010)。
文摘The reignition of aero-engine combustors at high altitudes poses significant challenges due to the low-temperature and low-pressure environment.A novel Long Pulse-Width Plasma Ignition(LPWPI)system has been developed to enhance ignition performance.The LPWPI system can effectively prolong the discharge duration time,improve ignition efficacy,and increase the plasma penetration depth.Experimental comparisons with the traditional Spark Ignition(SI)system demonstrate that the LPWPI increased discharge duration to 2.03 ms,which is 45 times longer than that of the SI system,while also doubling the spark penetration depth to 24.1 mm.The LPWPI system achieved a discharge efficiency of 61.1%,significantly surpassing the SI system's efficiency of23.3%.These advancements facilitated an extension of the lean ignition boundary by approximately 22.7%to 39.3%.High-speed camera recordings reveal that the spark duration of the LPWPI system was extended to 2.1 ms,compared to 0.6 ms in the SI system.Ignition progress with LPWPI shows a sustained spark kernel without the flame residence stage observed in the SI system.The impressive performance of the LPWPI system suggests that it is a promising alternative for aero-engine ignition systems.
基金supported in part by the Key Technologies Research and Development Program of Jiangsu(Prospective and Key Technologies for Industry)under Grant BE2023022 and BE2023022-1in part by National Natural Science Foundation of China(NSFC)under Grant 62401137,62401640,and 62231009+3 种基金in part by the Natural Science Foundation of Jiangsu Province under Grant BK20241281in part by the China National Postdoctoral Program for Innovative Talents under Grant BX20230065 and 2024M750421in part by the Jiangsu Excellent Postdoctoral Program under Grant 2023ZB476in part by the Guangdong Basic and Applied Basic Research Foundation under Grant 2023A1515110732.
文摘Channel state information(CSI)is essen-tial to unlock the potential of reconfigurable intelli-gent surfaces(RISs)in wireless communication sys-tems.Since massive RIS elements are typically imple-mented without baseband signal processing capabili-ties,limited CSI feedback is necessary when design-ing the reflection/refraction coefficients of the RIS.In this article,the unique RIS-assisted channel features,such as the RIS position-dependent channel fluctua-tion,the ultra-high dimensional sub-channel matrix,and the structured sparsity,are distilled from recent advances in limited feedback and used as guidelines for designing feedback schemes.We begin by il-lustrating the use cases and the corresponding chal-lenges associated with RIS feedback.We then discuss how to leverage techniques such as channel customiza-tion,structured-sparsity,autoencoders,and others to reduce feedback overhead and complexity when de-vising feedback schemes.Finally,we identify poten-tial research directions by considering the unresolved challenges,the new RIS architecture,and the integra-tion with multi-modal information and artificial intel-ligence.
文摘Application of variable speed limits(VSL)is gradually increasingly implemented especially on highways.As a result of conducted studies and implementations,it is observed that the variable speed limits have reduced the number of car accidents as well as proved positive results in terms of delays and environmental factors.Purpose of this study is to develop an algorithm for VSL application that is considered to be applied on Istanbul D100 highway and to assess the effects of application.Algorithm that is developed for VSL is a different VSL algorithm and compared with the constant speed system.According to obtained results,when the proposed system is compared to current system,it is observed that the number of delays and average stops are reduced%30 and%40 respectively and also emissions reduced at the rate of%12.
文摘On July 24th, Lectra's Board of Directors, chaired by Daniel Harari, reviewed the consolidated financial statements for the first half of 2025, which have been subject to a limited review by the Statutory Auditors.
基金supported by the Natural Science Foundation of Hunan Province(2022JJ30655)the National Natural Science Foundation of China(12371180)the Training Program for Excellent Young Innovators of Changsha(kq2305046)。
文摘In this paper,we investigate the propagation of chaos for solutions to the Liouville equation derived from the Linear-Formation particle model.By imposing certain conditions,we derive the rate of convergence between the k-tensor product f_(t)^(■k)of the solution to be Linear-Formation kinetic equation and the k-marginal f_(N,k)^(t)of the solution to the Liouville equation corresponding to the Linear-Formation particle model.Specifically,the following estimate holds in terms of p-Wasserstein(1≤p<∞)distance W_(p)^(p)(f_(t)^(■k),f_(N,k)^(t))≤C_(1)k/N^(min(p/2,1))(1+t^(p))e^(C_(2)^(t)),1≤k≤N.
