Brookhart-typeα-diimine nickel and palladium catalysts have been extensively studied over the past several decades;however,the heterogenization of these metal complexes has received much less attention.In this contri...Brookhart-typeα-diimine nickel and palladium catalysts have been extensively studied over the past several decades;however,the heterogenization of these metal complexes has received much less attention.In this contribution,we installed a trifluoroborate potassium substituent on anα-diimine framework.The ionic nature of trifluoroborate potassium endowed theα-diimine nickel complex with a strong affinity for the SiO_(2)support,while its electron-donating nature enhanced the catalyst stability and polyethylene molecular weight.In the presence of only 100 equiv.of Et2AlCl cocatalyst,the SiO_(2)-supported catalyst demonstrated significantly better performance than its homogeneous analog during ethylene polymerization,with extremely high activity(1.42–6.53×10^(7)g mol^(−1)h^(−1))and high thermal stability.The heterogeneous system led to the formation of high-molecular-weight polyethylenes(Mn 142,500–732,800 g/mol),narrow polydispersities(2.18–3.00),tunable branching densities(21–64 per 1000 carbon atoms),and great mechanical properties.Moreover,the efficient copolymerization of ethylene with comonomers such as methyl 10-undecenoate,6-chloro-1-hexene or 5-hexenylacetate was achieved.These superior properties enabled by the trifluoroborate potassium moiety may inspire its applications in other polymerization catalyst systems.展开更多
Metal isolated single atomic sites catalysts have attracted intensive attention in recent years owing to their maximized atom utilization and unique structure.Despite the success of single atom catalyst synthesis,dire...Metal isolated single atomic sites catalysts have attracted intensive attention in recent years owing to their maximized atom utilization and unique structure.Despite the success of single atom catalyst synthesis,directly anchoring metal single atoms on three-dimensional(3D)macro support,which is promising to achieve the heterogenization of homogeneous catalysis,remains a challenge and a blank in this field.Herein,we successfully fabricate metal single atoms(Pd,Pt,Ru,Au)on porous carbon nitride/reduced graphene oxide(C3N4/rGO)foam as highly efficient catalysts with convenient recyclability.C3N4/rGO foam features two-dimensional microstructures with abundant N chelating sites for the stabilization of metal single atoms and vertically-aligned hierarchical mesostructure that benefits the mass diffusion.The obtained Pdi/C3N4/rGO monolith catalyst exhibits much enhanced activity over its nanoparticle counterpart for Suzuki-Miyaura reaction.Moreover,the Pdi/C3N4/rGO monolith catalyst can be readily assembled in a flow reactor to achieve the highly efficient continuous production of 4-nitro-1,1'-biphenyl through Suzuki-Miyaura coupling.展开更多
A facile approach for the heterogenization of transition metal catalysts using non-covalent interactions in hollow click-based porous organic polymers （H-CPPs） is presented. A catalytically active cationic species, ...A facile approach for the heterogenization of transition metal catalysts using non-covalent interactions in hollow click-based porous organic polymers （H-CPPs） is presented. A catalytically active cationic species, [Ru（bpy）3]〉 （bpy = 2,2＇-bipyridyl）, was immobilized in H-CPPs via electrostatic interactions. The intrinsic properties of [Ru（bpy）3]〉 were well retained. The resulting Ru- containing hollow polymers exhibited excellent catalytic activity, enhanced stability, and good recyclability when used for the oxidative hydroxylation of 4-methoxyphenylboronic acid to 4-methoxyphenol under visible-light irradiation. The attractive catalytic performance mainly resulted from efficient mass transfer and the maintenance of the chemical properties of the cationic Ru complex in the H-CPPs.展开更多
Cyclohexene is an important raw material in the production of nylon.Selective hydrogenation of benzene is a key method for preparing cyclohexene.However,the Ru catalysts used in current industrial processes still face...Cyclohexene is an important raw material in the production of nylon.Selective hydrogenation of benzene is a key method for preparing cyclohexene.However,the Ru catalysts used in current industrial processes still face challenges,including high metal usage,high process costs,and low cyclohexene yield.This study utilizes existing literature data combined with machine learning methods to analyze the factors influencing benzene conversion,cyclohexene selectivity,and yield in the benzene hydrogenation to cyclohexene reaction.It constructs predictive models based on XGBoost and Random Forest algorithms.After analysis,it was found that reaction time,Ru content,and space velocity are key factors influencing cyclohexene yield,selectivity,and benzene conversion.Shapley Additive Explanations(SHAP)analysis and feature importance analysis further revealed the contribution of each variable to the reaction outcomes.Additionally,we randomly generated one million variable combinations using the Dirichlet distribution to attempt to predict high-yield catalyst formulations.This paper provides new insights into the application of machine learning in heterogeneous catalysis and offers some reference for further research.展开更多
The Keggin-type heteropolyacids（HPAs）, as the new multifunctional catalysts,show excellent activity for various homogeneous reactions. In recent years, the HPAshave been applied to many industrial processes. Heterog...The Keggin-type heteropolyacids（HPAs）, as the new multifunctional catalysts,show excellent activity for various homogeneous reactions. In recent years, the HPAshave been applied to many industrial processes. Heterogenization of the HPAswould make the homogeneous reactions heterogeneous, which is more easily applicableand has aroused great interest of chemists. This note reports the heterogenization of12-silicotungtic acid (SiW<sub>12</sub>)with the chemically treated bentonite as the support.展开更多
The ubiquitous adoption of mobile devices as essential platforms for sensitive data transmission has heightened the demand for secure client-server communication.Although various authentication and key agreement proto...The ubiquitous adoption of mobile devices as essential platforms for sensitive data transmission has heightened the demand for secure client-server communication.Although various authentication and key agreement protocols have been developed,current approaches are constrained by homogeneous cryptosystem frameworks,namely public key infrastructure(PKI),identity-based cryptography(IBC),or certificateless cryptography(CLC),each presenting limitations in client-server architectures.Specifically,PKI incurs certificate management overhead,IBC introduces key escrow risks,and CLC encounters cross-system interoperability challenges.To overcome these shortcomings,this study introduces a heterogeneous signcryption-based authentication and key agreement protocol that synergistically integrates IBC for client operations(eliminating PKI’s certificate dependency)with CLC for server implementation(mitigating IBC’s key escrow issue while preserving efficiency).Rigorous security analysis under the mBR(modified Bellare-Rogaway)model confirms the protocol’s resistance to adaptive chosen-ciphertext attacks.Quantitative comparisons demonstrate that the proposed protocol achieves 10.08%–71.34%lower communication overhead than existing schemes across multiple security levels(80-,112-,and 128-bit)compared to existing protocols.展开更多
A rapidly growing field is piezoresistive sensor for accurate respiration rate monitoring to suppress the worldwide respiratory illness.However,a large neglected issue is the sensing durability and accuracy without in...A rapidly growing field is piezoresistive sensor for accurate respiration rate monitoring to suppress the worldwide respiratory illness.However,a large neglected issue is the sensing durability and accuracy without interference since the expiratory pressure always coupled with external humidity and temperature variations,as well as mechanical motion artifacts.Herein,a robust and biodegradable piezoresistive sensor is reported that consists of heterogeneous MXene/cellulose-gelation sensing layer and Ag-based interdigital electrode,featuring customizable cylindrical interface arrangement and compact hierarchical laminated architecture for collectively regulating the piezoresistive response and mechanical robustness,thereby realizing the long-term breath-induced pressure detection.Notably,molecular dynamics simulations reveal the frequent angle inversion and reorientation of MXene/cellulose in vacuum filtration,driven by shear forces and interfacial interactions,which facilitate the establishment of hydrogen bonds and optimize the architecture design in sensing layer.The resultant sensor delivers unprecedented collection features of superior stability for off-axis deformation(0-120°,~2.8×10^(-3) A)and sensing accuracy without crosstalk(humidity 50%-100%and temperature 30-80).Besides,the sensor-embedded mask together with machine learning models is achieved to train and classify the respiration status for volunteers with different ages(average prediction accuracy~90%).It is envisioned that the customizable architecture design and sensor paradigm will shed light on the advanced stability of sustainable electronics and pave the way for the commercial application in respiratory monitory.展开更多
Industrial Cyber-Physical Systems(ICPSs)play a vital role in modern industries by providing an intellectual foundation for automated operations.With the increasing integration of information-driven processes,ensuring ...Industrial Cyber-Physical Systems(ICPSs)play a vital role in modern industries by providing an intellectual foundation for automated operations.With the increasing integration of information-driven processes,ensuring the security of Industrial Control Production Systems(ICPSs)has become a critical challenge.These systems are highly vulnerable to attacks such as denial-of-service(DoS),eclipse,and Sybil attacks,which can significantly disrupt industrial operations.This work proposes an effective protection strategy using an Artificial Intelligence(AI)-enabled Smart Contract(SC)framework combined with the Heterogeneous Barzilai-Borwein Support Vector(HBBSV)method for industrial-based CPS environments.The approach reduces run time and minimizes the probability of attacks.Initially,secured ICPSs are achieved through a comprehensive exchange of views on production plant strategies for condition monitoring using SC and blockchain(BC)integrated within a BC network.The SC executes the HBBSV strategy to verify the security consensus.The Barzilai-Borwein Support Vectorized algorithm computes abnormal attack occurrence probabilities to ensure that components operate within acceptable production line conditions.When a component remains within these conditions,no security breach occurs.Conversely,if a component does not satisfy the condition boundaries,a security lapse is detected,and those components are isolated.The HBBSV method thus strengthens protection against DoS,eclipse,and Sybil attacks.Experimental results demonstrate that the proposed HBBSV approach significantly improves security by enhancing authentication accuracy while reducing run time and authentication time compared to existing techniques.展开更多
To obtain protease-and lipase-producing halotolerant/halophilic strains suitable for shrimp paste(SP)fermentation,the microbial community structure and enzyme-producing microbial species were analyzed and predicted us...To obtain protease-and lipase-producing halotolerant/halophilic strains suitable for shrimp paste(SP)fermentation,the microbial community structure and enzyme-producing microbial species were analyzed and predicted using metagenomics in 3 high-salt samples.Based on the linear salt gradient method,128 strains were screened.Eight halotolerant/halophilic strains highly producing 2 types of enzymes were identified and inoculated into lowsalt SP to assess the heterogeneity of SP.Physicochemical properties of SP indicated that Bacillus subtilis XJ-11,Virgibacillus halodenitrificans XJ-229,Piscibacillus halophilus XY-193,and Bacillus vallismortis HT-73 were more suitable for rapid fermentation of SP.Nutritional analysis showed that SP inoculated with V.halodenitrificans XJ-229 had the highest free amino acid content and SP inoculated with P.halophilus XY-193 had the highest unsaturated fatty acid content.The former had prominent umami,sweetness,and meaty aroma,weak bitterness and fishy flavor,and the closest flavor to the control(CP)based on sensory evaluation and E-nose analysis.A total of 61 volatile compounds were detected in all samples by SPME-GC-MS,of which 32,23,40,24,and 28 were detected in the CP and SP inoculated with B.subtilis XJ-11,V.halodenitrificans XJ-229,P.halophilus XY-193,and B.vallismortis HT-73,respectively,with 12,11,12,9,and 9 key flavor compounds.Among several samples,the highest levels of pyrazines,aldehydes,alcohols,and ketones were found in SP inoculated with B.subtilis XJ-11,V.halodenitrificans XJ-229,P.halophilus XY-193,and B.vallismortis HT-73,respectively.These results suggested that inoculation of different enzyme-producing halotolerant/halophilic strains resulted in differences in SP quality and main flavors.This study provides some references for process control and interpretation of heterogeneous mechanisms in low-salt SP fermented by inoculated strains.展开更多
In recent years,three-dimensional reconstruction technologies that employ multiple cameras have continued to evolve significantly,enabling remote collaboration among users in extended Reality(XR)environments.In additi...In recent years,three-dimensional reconstruction technologies that employ multiple cameras have continued to evolve significantly,enabling remote collaboration among users in extended Reality(XR)environments.In addition,methods for deploying multiple cameras for motion capture of users(e.g.,performers)are widely used in computer graphics.As the need to minimize and optimize the number of cameras grows to reduce costs,various technologies and research approaches focused on Optimal Camera Placement(OCP)are continually being proposed.However,as most existing studies assume homogeneous camera setups,there is a growing demand for studies on heterogeneous camera setups.For instance,technical demands keep emerging in scenarios with minimal camera configurations,especially regarding cost factors,the physical placement of cameras given the spatial structure,and image capture strategies for heterogeneous cameras,such as high-resolution RGB cameras and depth cameras.In this study,we propose a pre-visualization and simulation method for the optimal placement of heterogeneous cameras in XR environments,accounting for both the specifications of heterogeneous cameras(e.g.,field of view)and the physical configuration(e.g.,wall configuration)in real-world spaces.The proposed method performs a visibility analysis of cameras by considering each camera’s field-of-view volume,resolution,and unique characteristics,along with physicalspace constraints.This approach enables the optimal position and rotation of each camera to be recommended,along with the minimum number of cameras required.In the results of our study conducted in heterogeneous camera combinations,the proposed method achieved 81.7%~82.7%coverage of the target visual information using only 2~3 cameras.In contrast,single(or homogeneous)-typed cameras were required to use 11 cameras for 81.6%coverage.Accordingly,we found that camera deployment resources can be reduced with the proposed approaches.展开更多
With the increasing complexity of malware attack techniques,traditional detection methods face significant challenges,such as privacy preservation,data heterogeneity,and lacking category information.To address these i...With the increasing complexity of malware attack techniques,traditional detection methods face significant challenges,such as privacy preservation,data heterogeneity,and lacking category information.To address these issues,we propose Federated Dynamic Prototype Learning(FedDPL)for malware classification by integrating Federated Learning with a specifically designed K-means.Under the Federated Learning framework,model training occurs locally without data sharing,effectively protecting user data privacy and preventing the leakage of sensitive information.Furthermore,to tackle the challenges of data heterogeneity and the lack of category information,FedDPL introduces a dynamic prototype learning mechanism,which adaptively adjusts the clustering prototypes in terms of position and number.Thus,the dependency on predefined category numbers in typical K-means and its variants can be significantly reduced,resulting in improved clustering performance.Theoretically,it provides a more accurate detection of malicious behavior.Experimental results confirm that FedDPL excels in handling malware classification tasks,demonstrating superior accuracy,robustness,and privacy protection.展开更多
Heterogeneous polymerization represents a widely employed method in the polyolefin industry.In recent years,various heterogenization strategies for late transition metal catalysts have been developed,enabling effectiv...Heterogeneous polymerization represents a widely employed method in the polyolefin industry.In recent years,various heterogenization strategies for late transition metal catalysts have been developed,enabling effective control of polymer morphology and optimization of catalytic performance.However,while most studies have focused on designing anchoring groups and advancing support approaches,systematic investigations into how the support influences the catalytic behavior of the late transition metal catalysts.In this work,we fabricated supported α-diimine nickel catalysts by functionalizing the ligand with alkyl alcohol chains of varying lengths and supporting them onto MgCl_(2)supports.The ethylene polymerization behavior of these catalysts was then investigated.By precisely adjusting the alkyl alcohol chain length,the distance between the catalytically active metal center and the support surface was modulated.This approach demonstrates that support-induced steric hindrance effect can be effectively regulated by controlling the separation distance between the metal center and the support surface.展开更多
Due to the advantages of green and sustainable chemistry,electrochemistry has attracted considerable interest from researchers in both academia and industry.Organic electrosynthesis has become a revolutionary strategy...Due to the advantages of green and sustainable chemistry,electrochemistry has attracted considerable interest from researchers in both academia and industry.Organic electrosynthesis has become a revolutionary strategy,which offers a greener and more energy-efficient option for traditional organic synthesis.This mini review summarizes examples of organic electrosynthesis that highlight the unique potential of organic electrosynthesis in asymmetric electrocatalysis,photoelectrocatalysis,heterogeneous electrocatalysis,and alternating current electrolysis,aiming to stimulate future progress in this rapidly evolving area.展开更多
Computational phantoms play an essential role in radiation dosimetry and health physics.Although mesh-type phantoms offer a high resolution and adjustability,their use in dose calculations is limited by their slow com...Computational phantoms play an essential role in radiation dosimetry and health physics.Although mesh-type phantoms offer a high resolution and adjustability,their use in dose calculations is limited by their slow computational speed.Progress in heterogeneous computing has allowed for substantial acceleration in the computation of mesh-type phantoms by utilizing hardware accelerators.In this study,a GPU-accelerated Monte Carlo method was developed to expedite the dose calculation for mesh-type computational phantoms.This involved designing and implementing the entire procedural flow of a GPUaccelerated Monte Carlo program.We employed acceleration structures to process the mesh-type phantom,optimized the traversal methodology,and achieved a flattened structure to overcome the limitations of GPU stack depths.Particle transport methods were realized within the mesh-type phantom,encompassing particle location and intersection techniques.In response to typical external irradiation scenarios,we utilized Geant4 along with the GPU program and its CPU serial code for dose calculations,assessing both computational accuracy and efficiency.In comparison with the benchmark simulated using Geant4 on the CPU using one thread,the relative differences in the organ dose calculated by the GPU program predominantly lay within a margin of 5%,whereas the computational time was reduced by a factor ranging from 120 to 2700.To the best of our knowledge,this study achieved a GPU-accelerated dose calculation method for mesh-type phantoms for the first time,reducing the computational time from hours to seconds per simulation of ten million particles and offering a swift and precise Monte Carlo method for dose calculation in mesh-type computational phantoms.展开更多
The vertical heterogeneity of the pore structure in deep coal seams with varying ash yields is a key control for coalbed methane storage and producibility;however,its specific impact on gas adsorption is not clearly d...The vertical heterogeneity of the pore structure in deep coal seams with varying ash yields is a key control for coalbed methane storage and producibility;however,its specific impact on gas adsorption is not clearly defined.The focus of this study is the No.8 coal seam of the Carboniferous Benxi Formation in the Central-Eastern Ordos Basin.By integrating microscopic identification,proximate analysis,gas adsorption(CO_(2),N_(2),and CH_(4)),and the multifractal theory,we quantitatively characterized the nanopore structure(micropores<2 nm and mesopores 2 nm-100 nm)of coal reservoirs with varying ash yields.The results indicate that(1)ash yield is the primary factor that controls the vertical evolution of pore structures in coal seams.In low-ash yield coal seams,the extent of thermal evolution and ash yield jointly constrain the heterogeneity of pore size distribution.In mediumto high-ash yield coal seams,the heterogeneity of pore structure and pore size distribution are predominantly constrained by ash yield.(2)As the ash yield vertically increases,the mesoporous pore volume and specific surface area initially decrease and subsequently increase,while the contribution of micropores to both pore volume and specific surface area continuously diminishes.Consequently,the total pore volume and specific surface area of the coal samples exhibit a two-stage reduction close to an ash yield threshold of approximately 20%.(3)Further,the Langmuir volume for CH_(4)adsorption sharply declines below the 20%threshold,followed by a gradual decrease;in contrast,the Langmuir pressure initially decreases and subsequently increases.Hence,the vertical increase in ash yield constrains the development of pore systems and diminishes pore connectivity,thereby reducing methane adsorption capacity and adversely affecting coalbed methane productivity.(4)Low-ash yield coal reservoirs are characterized by a rapid gas breakthrough and high productivity,whereas medium-ash yield coal reservoirs generally require prolonged depressurization to achieve peak gas production.These findings reveal that in medium-high rank coal,ash yield―and not thermal evolution―is the main factor that controls vertical pore evolution and methane adsorption efficiency.The quantitative ash yield threshold(20%)established in this study provides a practical criterion for evaluating reservoir quality and predicting vertical variations in gas storage potential in the Ordos Basin.展开更多
Mantle geochemistry,a field that emerged in the mid-1970s,utilizes geochemical approaches to investigate the chemical composition and structure as well as the evolution and dynamics of Earth’s mantle.Since its establ...Mantle geochemistry,a field that emerged in the mid-1970s,utilizes geochemical approaches to investigate the chemical composition and structure as well as the evolution and dynamics of Earth’s mantle.Since its establishment,this field has become a key part of solid Earth Science and Planetary Science,demonstrating great vitality.The development of its theoretical framework began with the observation of mantle heterogeneity revealed by the radiogenic isotopic compositions of ocean island basalts(OIBs)and mid-ocean ridge basalts(MORBs),which in turn gave rise to the classic“crustal recycling”model.Based on this,a suite of globally representative mantle end-member components,namely DMM(Depleted MORB Mantle),EMI(Enriched Mantle I),EMII(Enriched Mantle II),HIMU(Highμ,μ=^(238)U/^(204)Pb)and PREMA(prevalent mantle),was identified,thereby establishing a comprehensive framework to characterize the geochemical structure and geodynamic system of the mantle.Over the past five decades,mantle geochemistry has advanced with new analytical techniques and theoretical development,greatly broadening its scope.It is now a key field within the Earth System Sciences,crucial for developing models of deep material cycling and surface environmental responses.Aiming to review the development of mantle geochemistry,this paper analyzes eight seminal studies focused on radiogenic isotopes,revisiting the establishment and evolution of mantle geochemistry,exploring the scientific vision of pioneers and highlighting the key topics that define this discipline.展开更多
Fault-tolerant systems are crucial for ensuring the reliability and availability of missioncritical applications in modern computing environments.The dynamic heterogeneous redundancy(DHR)architecture is a key componen...Fault-tolerant systems are crucial for ensuring the reliability and availability of missioncritical applications in modern computing environments.The dynamic heterogeneous redundancy(DHR)architecture is a key component in constructing fault-tolerant systems,particularly in areas such as national security,power networks,and banking private networks.DHR is transforming the cyberspace security industry chain by accommodating a broader range of applications and increasingly capturing the market.However,the development of applications for DHR architecture encounters challenges due to the complexities of handling heterogeneity,managing dynamism,and maintaining usability.To address these issues,we introduce MimicStudio,a comprehensive development framework with a standardized workflow.To our knowledge,MimicStudio is the first effective solution for DHR software development.We present a detailed implementation of MimicStudio with a heterogeneous microcontroller unit project,encompassing three CPUs with different instruction set architectures.The paper evaluates MimicStudio’s support for essential features,including zero-copy synchronization,parallelized build,multi-core collaborative debugging,and dynamic adjustment of the software system’s structure.Our results show that MimicStudio provides a flexible and efficient solution for supporting the dynamic,heterogeneous,and redundant features of fault-tolerant systems.展开更多
Rock damage significantly affects coupled thermo-hydro-mechanical(THM)behavior in deep geothermal exploitation through changing thermal and hydrological properties of rocks.For this,a thermo-hydro-mechanical-damage(TH...Rock damage significantly affects coupled thermo-hydro-mechanical(THM)behavior in deep geothermal exploitation through changing thermal and hydrological properties of rocks.For this,a thermo-hydro-mechanical-damage(THMD)coupled model was developed to describe the coupling between rock damage and mechanical,fluid flow and heat transfer fields.The model considers rock heterogeneity,and incorporates the Mohr-Coulomb failure criterion and the maximum tensile stress criterion to evaluate shear and tensile damage.This numerical modeling methodology was first verified against analytical solutions and experimental results,and was then used to simulate the THMD coupling behavior in deep geothermal exploitation.A coupled numerical model was set up to simulate the geothermal fluids extraction and re-injection process in a reservoir at 1 km depth over a 7-year period.Rock damage was found to accelerate the propagation of cold fronts away from the injection well,and have a distinct effect on the performance of geothermal exploitation.When the rock damage was considered,the field injectivity increases by 8.4 times,the range of cooled regions increases by 18.6 times,and the vertical deformation changes by 1.2 times after 7 years of geothermal operations,compared to the scenario where it was not considered.Parametric studies have suggested that thermal contraction dominates the rock damage evolution,and that thermal-induced rock damage only occurs at a sufficiently large temperature difference between fluids injected and the reservoir.This work underscores the importance of accurately accounting for the damage effect on reservoir response during fluid injection activities that cause significant cooling of reservoir rocks.展开更多
In this paper,a hierarchical reinforcement learning(HRL)based real-time formation control approach is proposed for heterogeneous aerial-ground agents(HAGAs).Initially,to address the issue of imprecise modeling of HAGA...In this paper,a hierarchical reinforcement learning(HRL)based real-time formation control approach is proposed for heterogeneous aerial-ground agents(HAGAs).Initially,to address the issue of imprecise modeling of HAGAs,a unified heterogeneous chained system model is constructed using the hand-position method.Subsequently,a hierarchical framework is designed:(1)To decouple multi-agent collaborative interactions and individual dynamic rules through hierarchical resolution,which enables controller design to be independent of direct reliance on neighborhood collaborative errors.(2)By adopting a dual-layer framework that separates collaborative topology management from individual control strategies,seamless switching between multiple task scenarios can be achieved simply by reconstructing the collaborative topology of the first layer.Moreover,to overcome the issue of non-asymptotic stability of tracking errors caused by the discount factor in traditional optimal control,a cost function based on the derivative of the tracking error is introduced.This not only addresses the error issue caused by the discount factor but also effectively resolves the problem of the unboundedness of the quadratic cost function.Finally,the efficacy of the proposed algorithm is substantiated through simulation experiments.展开更多
基金supported by National Key R&D Program of China(No.2021YFA1501700)National Natural Science Foundation of China(Nos.52025031,U19B6001 and U1904212)K.C.Wong Education Foundation.
文摘Brookhart-typeα-diimine nickel and palladium catalysts have been extensively studied over the past several decades;however,the heterogenization of these metal complexes has received much less attention.In this contribution,we installed a trifluoroborate potassium substituent on anα-diimine framework.The ionic nature of trifluoroborate potassium endowed theα-diimine nickel complex with a strong affinity for the SiO_(2)support,while its electron-donating nature enhanced the catalyst stability and polyethylene molecular weight.In the presence of only 100 equiv.of Et2AlCl cocatalyst,the SiO_(2)-supported catalyst demonstrated significantly better performance than its homogeneous analog during ethylene polymerization,with extremely high activity(1.42–6.53×10^(7)g mol^(−1)h^(−1))and high thermal stability.The heterogeneous system led to the formation of high-molecular-weight polyethylenes(Mn 142,500–732,800 g/mol),narrow polydispersities(2.18–3.00),tunable branching densities(21–64 per 1000 carbon atoms),and great mechanical properties.Moreover,the efficient copolymerization of ethylene with comonomers such as methyl 10-undecenoate,6-chloro-1-hexene or 5-hexenylacetate was achieved.These superior properties enabled by the trifluoroborate potassium moiety may inspire its applications in other polymerization catalyst systems.
基金This work was supported by the National Key R&D Program of China(No.2018YFA0702003)the National Natural Science Foundation of China(No.21890383,21971137)Beijing Municipal Science&Technology Commission(No.Z191100007219003)。
文摘Metal isolated single atomic sites catalysts have attracted intensive attention in recent years owing to their maximized atom utilization and unique structure.Despite the success of single atom catalyst synthesis,directly anchoring metal single atoms on three-dimensional(3D)macro support,which is promising to achieve the heterogenization of homogeneous catalysis,remains a challenge and a blank in this field.Herein,we successfully fabricate metal single atoms(Pd,Pt,Ru,Au)on porous carbon nitride/reduced graphene oxide(C3N4/rGO)foam as highly efficient catalysts with convenient recyclability.C3N4/rGO foam features two-dimensional microstructures with abundant N chelating sites for the stabilization of metal single atoms and vertically-aligned hierarchical mesostructure that benefits the mass diffusion.The obtained Pdi/C3N4/rGO monolith catalyst exhibits much enhanced activity over its nanoparticle counterpart for Suzuki-Miyaura reaction.Moreover,the Pdi/C3N4/rGO monolith catalyst can be readily assembled in a flow reactor to achieve the highly efficient continuous production of 4-nitro-1,1'-biphenyl through Suzuki-Miyaura coupling.
基金The authors are grateful to the financial support of the National Basic Research Program of China （Nos. 2011CBA00502 and 2014CB260410）, National Natural Science Foundation of China （Nos. 21403238, 21373050, U1305242, and 21471151） and Major Project of Fujian Province （No. 2014H0053）.
文摘A facile approach for the heterogenization of transition metal catalysts using non-covalent interactions in hollow click-based porous organic polymers （H-CPPs） is presented. A catalytically active cationic species, [Ru（bpy）3]〉 （bpy = 2,2＇-bipyridyl）, was immobilized in H-CPPs via electrostatic interactions. The intrinsic properties of [Ru（bpy）3]〉 were well retained. The resulting Ru- containing hollow polymers exhibited excellent catalytic activity, enhanced stability, and good recyclability when used for the oxidative hydroxylation of 4-methoxyphenylboronic acid to 4-methoxyphenol under visible-light irradiation. The attractive catalytic performance mainly resulted from efficient mass transfer and the maintenance of the chemical properties of the cationic Ru complex in the H-CPPs.
基金Supported by CAS Basic and Interdisciplinary Frontier Scientific Research Pilot Project(XDB1190300,XDB1190302)Youth Innovation Promotion Association CAS(Y2021056)+1 种基金Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(YLU-DNL Fund 2022007)The special fund for Science and Technology Innovation Teams of Shanxi Province(202304051001007)。
文摘Cyclohexene is an important raw material in the production of nylon.Selective hydrogenation of benzene is a key method for preparing cyclohexene.However,the Ru catalysts used in current industrial processes still face challenges,including high metal usage,high process costs,and low cyclohexene yield.This study utilizes existing literature data combined with machine learning methods to analyze the factors influencing benzene conversion,cyclohexene selectivity,and yield in the benzene hydrogenation to cyclohexene reaction.It constructs predictive models based on XGBoost and Random Forest algorithms.After analysis,it was found that reaction time,Ru content,and space velocity are key factors influencing cyclohexene yield,selectivity,and benzene conversion.Shapley Additive Explanations(SHAP)analysis and feature importance analysis further revealed the contribution of each variable to the reaction outcomes.Additionally,we randomly generated one million variable combinations using the Dirichlet distribution to attempt to predict high-yield catalyst formulations.This paper provides new insights into the application of machine learning in heterogeneous catalysis and offers some reference for further research.
文摘The Keggin-type heteropolyacids（HPAs）, as the new multifunctional catalysts,show excellent activity for various homogeneous reactions. In recent years, the HPAshave been applied to many industrial processes. Heterogenization of the HPAswould make the homogeneous reactions heterogeneous, which is more easily applicableand has aroused great interest of chemists. This note reports the heterogenization of12-silicotungtic acid (SiW<sub>12</sub>)with the chemically treated bentonite as the support.
基金supported by the Key Project of Science and Technology Research by Chongqing Education Commission under Grant KJZD-K202400610the Chongqing Natural Science Foundation General Project Grant CSTB2025NSCQ-GPX1263.
文摘The ubiquitous adoption of mobile devices as essential platforms for sensitive data transmission has heightened the demand for secure client-server communication.Although various authentication and key agreement protocols have been developed,current approaches are constrained by homogeneous cryptosystem frameworks,namely public key infrastructure(PKI),identity-based cryptography(IBC),or certificateless cryptography(CLC),each presenting limitations in client-server architectures.Specifically,PKI incurs certificate management overhead,IBC introduces key escrow risks,and CLC encounters cross-system interoperability challenges.To overcome these shortcomings,this study introduces a heterogeneous signcryption-based authentication and key agreement protocol that synergistically integrates IBC for client operations(eliminating PKI’s certificate dependency)with CLC for server implementation(mitigating IBC’s key escrow issue while preserving efficiency).Rigorous security analysis under the mBR(modified Bellare-Rogaway)model confirms the protocol’s resistance to adaptive chosen-ciphertext attacks.Quantitative comparisons demonstrate that the proposed protocol achieves 10.08%–71.34%lower communication overhead than existing schemes across multiple security levels(80-,112-,and 128-bit)compared to existing protocols.
基金supported by the National Natural Science Foundation of China(22074072,22274083,52376199)the Shandong Provincial Natural Science Foundation(ZR2023LZY005)+1 种基金the Exploration Project of the State Key Laboratory of BioFibers and EcoTextiles of Qingdao University(TSKT202101)the Fundamental Research Funds for the Central Universities(2022BLRD13,2023BLRD01).
文摘A rapidly growing field is piezoresistive sensor for accurate respiration rate monitoring to suppress the worldwide respiratory illness.However,a large neglected issue is the sensing durability and accuracy without interference since the expiratory pressure always coupled with external humidity and temperature variations,as well as mechanical motion artifacts.Herein,a robust and biodegradable piezoresistive sensor is reported that consists of heterogeneous MXene/cellulose-gelation sensing layer and Ag-based interdigital electrode,featuring customizable cylindrical interface arrangement and compact hierarchical laminated architecture for collectively regulating the piezoresistive response and mechanical robustness,thereby realizing the long-term breath-induced pressure detection.Notably,molecular dynamics simulations reveal the frequent angle inversion and reorientation of MXene/cellulose in vacuum filtration,driven by shear forces and interfacial interactions,which facilitate the establishment of hydrogen bonds and optimize the architecture design in sensing layer.The resultant sensor delivers unprecedented collection features of superior stability for off-axis deformation(0-120°,~2.8×10^(-3) A)and sensing accuracy without crosstalk(humidity 50%-100%and temperature 30-80).Besides,the sensor-embedded mask together with machine learning models is achieved to train and classify the respiration status for volunteers with different ages(average prediction accuracy~90%).It is envisioned that the customizable architecture design and sensor paradigm will shed light on the advanced stability of sustainable electronics and pave the way for the commercial application in respiratory monitory.
文摘Industrial Cyber-Physical Systems(ICPSs)play a vital role in modern industries by providing an intellectual foundation for automated operations.With the increasing integration of information-driven processes,ensuring the security of Industrial Control Production Systems(ICPSs)has become a critical challenge.These systems are highly vulnerable to attacks such as denial-of-service(DoS),eclipse,and Sybil attacks,which can significantly disrupt industrial operations.This work proposes an effective protection strategy using an Artificial Intelligence(AI)-enabled Smart Contract(SC)framework combined with the Heterogeneous Barzilai-Borwein Support Vector(HBBSV)method for industrial-based CPS environments.The approach reduces run time and minimizes the probability of attacks.Initially,secured ICPSs are achieved through a comprehensive exchange of views on production plant strategies for condition monitoring using SC and blockchain(BC)integrated within a BC network.The SC executes the HBBSV strategy to verify the security consensus.The Barzilai-Borwein Support Vectorized algorithm computes abnormal attack occurrence probabilities to ensure that components operate within acceptable production line conditions.When a component remains within these conditions,no security breach occurs.Conversely,if a component does not satisfy the condition boundaries,a security lapse is detected,and those components are isolated.The HBBSV method thus strengthens protection against DoS,eclipse,and Sybil attacks.Experimental results demonstrate that the proposed HBBSV approach significantly improves security by enhancing authentication accuracy while reducing run time and authentication time compared to existing techniques.
基金supported by the National Natural Science Foundation of China(22138004)Shaoxing Science and Technology Plan Project(2022B43001,2023B43001).
文摘To obtain protease-and lipase-producing halotolerant/halophilic strains suitable for shrimp paste(SP)fermentation,the microbial community structure and enzyme-producing microbial species were analyzed and predicted using metagenomics in 3 high-salt samples.Based on the linear salt gradient method,128 strains were screened.Eight halotolerant/halophilic strains highly producing 2 types of enzymes were identified and inoculated into lowsalt SP to assess the heterogeneity of SP.Physicochemical properties of SP indicated that Bacillus subtilis XJ-11,Virgibacillus halodenitrificans XJ-229,Piscibacillus halophilus XY-193,and Bacillus vallismortis HT-73 were more suitable for rapid fermentation of SP.Nutritional analysis showed that SP inoculated with V.halodenitrificans XJ-229 had the highest free amino acid content and SP inoculated with P.halophilus XY-193 had the highest unsaturated fatty acid content.The former had prominent umami,sweetness,and meaty aroma,weak bitterness and fishy flavor,and the closest flavor to the control(CP)based on sensory evaluation and E-nose analysis.A total of 61 volatile compounds were detected in all samples by SPME-GC-MS,of which 32,23,40,24,and 28 were detected in the CP and SP inoculated with B.subtilis XJ-11,V.halodenitrificans XJ-229,P.halophilus XY-193,and B.vallismortis HT-73,respectively,with 12,11,12,9,and 9 key flavor compounds.Among several samples,the highest levels of pyrazines,aldehydes,alcohols,and ketones were found in SP inoculated with B.subtilis XJ-11,V.halodenitrificans XJ-229,P.halophilus XY-193,and B.vallismortis HT-73,respectively.These results suggested that inoculation of different enzyme-producing halotolerant/halophilic strains resulted in differences in SP quality and main flavors.This study provides some references for process control and interpretation of heterogeneous mechanisms in low-salt SP fermented by inoculated strains.
基金supported by the 2024 Research Fund of University of Ulsan.
文摘In recent years,three-dimensional reconstruction technologies that employ multiple cameras have continued to evolve significantly,enabling remote collaboration among users in extended Reality(XR)environments.In addition,methods for deploying multiple cameras for motion capture of users(e.g.,performers)are widely used in computer graphics.As the need to minimize and optimize the number of cameras grows to reduce costs,various technologies and research approaches focused on Optimal Camera Placement(OCP)are continually being proposed.However,as most existing studies assume homogeneous camera setups,there is a growing demand for studies on heterogeneous camera setups.For instance,technical demands keep emerging in scenarios with minimal camera configurations,especially regarding cost factors,the physical placement of cameras given the spatial structure,and image capture strategies for heterogeneous cameras,such as high-resolution RGB cameras and depth cameras.In this study,we propose a pre-visualization and simulation method for the optimal placement of heterogeneous cameras in XR environments,accounting for both the specifications of heterogeneous cameras(e.g.,field of view)and the physical configuration(e.g.,wall configuration)in real-world spaces.The proposed method performs a visibility analysis of cameras by considering each camera’s field-of-view volume,resolution,and unique characteristics,along with physicalspace constraints.This approach enables the optimal position and rotation of each camera to be recommended,along with the minimum number of cameras required.In the results of our study conducted in heterogeneous camera combinations,the proposed method achieved 81.7%~82.7%coverage of the target visual information using only 2~3 cameras.In contrast,single(or homogeneous)-typed cameras were required to use 11 cameras for 81.6%coverage.Accordingly,we found that camera deployment resources can be reduced with the proposed approaches.
基金supported by the National Natural Science Foundation of China under Grant No.62162009the Key Technologies R&D Program of He’nan Province under Grant No.242102211065+2 种基金the Postgraduate Education Reform and Quality Improvement Project of Henan Province under Grant Nos.YJS2025GZZ36,YJS2024AL112,and YJS2024JD38the Innovation Scientists and Technicians Troop Construction Projects of Henan Province under Grant No.CXTD2017099the Scientific Research Innovation Team of Xuchang University under Grant No.2022CXTD003.
文摘With the increasing complexity of malware attack techniques,traditional detection methods face significant challenges,such as privacy preservation,data heterogeneity,and lacking category information.To address these issues,we propose Federated Dynamic Prototype Learning(FedDPL)for malware classification by integrating Federated Learning with a specifically designed K-means.Under the Federated Learning framework,model training occurs locally without data sharing,effectively protecting user data privacy and preventing the leakage of sensitive information.Furthermore,to tackle the challenges of data heterogeneity and the lack of category information,FedDPL introduces a dynamic prototype learning mechanism,which adaptively adjusts the clustering prototypes in terms of position and number.Thus,the dependency on predefined category numbers in typical K-means and its variants can be significantly reduced,resulting in improved clustering performance.Theoretically,it provides a more accurate detection of malicious behavior.Experimental results confirm that FedDPL excels in handling malware classification tasks,demonstrating superior accuracy,robustness,and privacy protection.
基金financially supported by the National Natural Science Foundation of China(No.52473338)the National Natural Science Foundation of China(Nos.52173004 and 51873055)+3 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA0540000)Advanced Materials-National Science and Technology Major Project(No.2025ZD0614000)Hebei Natural Science Foundation(No.E2022202015)Anhui Province Science and Technology Innovation Tackling Key Project(No.202423i08050025)。
文摘Heterogeneous polymerization represents a widely employed method in the polyolefin industry.In recent years,various heterogenization strategies for late transition metal catalysts have been developed,enabling effective control of polymer morphology and optimization of catalytic performance.However,while most studies have focused on designing anchoring groups and advancing support approaches,systematic investigations into how the support influences the catalytic behavior of the late transition metal catalysts.In this work,we fabricated supported α-diimine nickel catalysts by functionalizing the ligand with alkyl alcohol chains of varying lengths and supporting them onto MgCl_(2)supports.The ethylene polymerization behavior of these catalysts was then investigated.By precisely adjusting the alkyl alcohol chain length,the distance between the catalytically active metal center and the support surface was modulated.This approach demonstrates that support-induced steric hindrance effect can be effectively regulated by controlling the separation distance between the metal center and the support surface.
基金supported by the National Key R&D Program of China(2021YFA1500104,2022YFA1505100)the National Natural Science Foundation of China(22031008,22401221)+3 种基金the Hubei Technological Innovation Program Funding(2025BAB025)the Science Foundation of Wuhan(2020010601012192)the Fundamental Research Funds for the Central Universities(2042025kf0016)the XIAOMI Foundation for its support。
文摘Due to the advantages of green and sustainable chemistry,electrochemistry has attracted considerable interest from researchers in both academia and industry.Organic electrosynthesis has become a revolutionary strategy,which offers a greener and more energy-efficient option for traditional organic synthesis.This mini review summarizes examples of organic electrosynthesis that highlight the unique potential of organic electrosynthesis in asymmetric electrocatalysis,photoelectrocatalysis,heterogeneous electrocatalysis,and alternating current electrolysis,aiming to stimulate future progress in this rapidly evolving area.
基金supported by the National Natural Science Foundation of China(Nos.U2167209 and 12375312)Open-end Fund Projects of China Institute for Radiation Protection Scientific Research Platform(CIRP-HYYFZH-2023ZD001).
文摘Computational phantoms play an essential role in radiation dosimetry and health physics.Although mesh-type phantoms offer a high resolution and adjustability,their use in dose calculations is limited by their slow computational speed.Progress in heterogeneous computing has allowed for substantial acceleration in the computation of mesh-type phantoms by utilizing hardware accelerators.In this study,a GPU-accelerated Monte Carlo method was developed to expedite the dose calculation for mesh-type computational phantoms.This involved designing and implementing the entire procedural flow of a GPUaccelerated Monte Carlo program.We employed acceleration structures to process the mesh-type phantom,optimized the traversal methodology,and achieved a flattened structure to overcome the limitations of GPU stack depths.Particle transport methods were realized within the mesh-type phantom,encompassing particle location and intersection techniques.In response to typical external irradiation scenarios,we utilized Geant4 along with the GPU program and its CPU serial code for dose calculations,assessing both computational accuracy and efficiency.In comparison with the benchmark simulated using Geant4 on the CPU using one thread,the relative differences in the organ dose calculated by the GPU program predominantly lay within a margin of 5%,whereas the computational time was reduced by a factor ranging from 120 to 2700.To the best of our knowledge,this study achieved a GPU-accelerated dose calculation method for mesh-type phantoms for the first time,reducing the computational time from hours to seconds per simulation of ten million particles and offering a swift and precise Monte Carlo method for dose calculation in mesh-type computational phantoms.
基金sponsored by the National Natural Science Foundation of China(Grant No.42202205)Natural Science Foundation of Shandong Province,China(Grant No.ZR2021QD072).-。
文摘The vertical heterogeneity of the pore structure in deep coal seams with varying ash yields is a key control for coalbed methane storage and producibility;however,its specific impact on gas adsorption is not clearly defined.The focus of this study is the No.8 coal seam of the Carboniferous Benxi Formation in the Central-Eastern Ordos Basin.By integrating microscopic identification,proximate analysis,gas adsorption(CO_(2),N_(2),and CH_(4)),and the multifractal theory,we quantitatively characterized the nanopore structure(micropores<2 nm and mesopores 2 nm-100 nm)of coal reservoirs with varying ash yields.The results indicate that(1)ash yield is the primary factor that controls the vertical evolution of pore structures in coal seams.In low-ash yield coal seams,the extent of thermal evolution and ash yield jointly constrain the heterogeneity of pore size distribution.In mediumto high-ash yield coal seams,the heterogeneity of pore structure and pore size distribution are predominantly constrained by ash yield.(2)As the ash yield vertically increases,the mesoporous pore volume and specific surface area initially decrease and subsequently increase,while the contribution of micropores to both pore volume and specific surface area continuously diminishes.Consequently,the total pore volume and specific surface area of the coal samples exhibit a two-stage reduction close to an ash yield threshold of approximately 20%.(3)Further,the Langmuir volume for CH_(4)adsorption sharply declines below the 20%threshold,followed by a gradual decrease;in contrast,the Langmuir pressure initially decreases and subsequently increases.Hence,the vertical increase in ash yield constrains the development of pore systems and diminishes pore connectivity,thereby reducing methane adsorption capacity and adversely affecting coalbed methane productivity.(4)Low-ash yield coal reservoirs are characterized by a rapid gas breakthrough and high productivity,whereas medium-ash yield coal reservoirs generally require prolonged depressurization to achieve peak gas production.These findings reveal that in medium-high rank coal,ash yield―and not thermal evolution―is the main factor that controls vertical pore evolution and methane adsorption efficiency.The quantitative ash yield threshold(20%)established in this study provides a practical criterion for evaluating reservoir quality and predicting vertical variations in gas storage potential in the Ordos Basin.
基金supported by the National Natural Science Foundation of China(Grant No.42130310).
文摘Mantle geochemistry,a field that emerged in the mid-1970s,utilizes geochemical approaches to investigate the chemical composition and structure as well as the evolution and dynamics of Earth’s mantle.Since its establishment,this field has become a key part of solid Earth Science and Planetary Science,demonstrating great vitality.The development of its theoretical framework began with the observation of mantle heterogeneity revealed by the radiogenic isotopic compositions of ocean island basalts(OIBs)and mid-ocean ridge basalts(MORBs),which in turn gave rise to the classic“crustal recycling”model.Based on this,a suite of globally representative mantle end-member components,namely DMM(Depleted MORB Mantle),EMI(Enriched Mantle I),EMII(Enriched Mantle II),HIMU(Highμ,μ=^(238)U/^(204)Pb)and PREMA(prevalent mantle),was identified,thereby establishing a comprehensive framework to characterize the geochemical structure and geodynamic system of the mantle.Over the past five decades,mantle geochemistry has advanced with new analytical techniques and theoretical development,greatly broadening its scope.It is now a key field within the Earth System Sciences,crucial for developing models of deep material cycling and surface environmental responses.Aiming to review the development of mantle geochemistry,this paper analyzes eight seminal studies focused on radiogenic isotopes,revisiting the establishment and evolution of mantle geochemistry,exploring the scientific vision of pioneers and highlighting the key topics that define this discipline.
基金supported by National Key Research and Development Program of China(No.2023YFB 4404200).
文摘Fault-tolerant systems are crucial for ensuring the reliability and availability of missioncritical applications in modern computing environments.The dynamic heterogeneous redundancy(DHR)architecture is a key component in constructing fault-tolerant systems,particularly in areas such as national security,power networks,and banking private networks.DHR is transforming the cyberspace security industry chain by accommodating a broader range of applications and increasingly capturing the market.However,the development of applications for DHR architecture encounters challenges due to the complexities of handling heterogeneity,managing dynamism,and maintaining usability.To address these issues,we introduce MimicStudio,a comprehensive development framework with a standardized workflow.To our knowledge,MimicStudio is the first effective solution for DHR software development.We present a detailed implementation of MimicStudio with a heterogeneous microcontroller unit project,encompassing three CPUs with different instruction set architectures.The paper evaluates MimicStudio’s support for essential features,including zero-copy synchronization,parallelized build,multi-core collaborative debugging,and dynamic adjustment of the software system’s structure.Our results show that MimicStudio provides a flexible and efficient solution for supporting the dynamic,heterogeneous,and redundant features of fault-tolerant systems.
基金funded by the Major National Science and Technology Project for Deep Earth of China(Grant No.2024ZD1003805)the National Natural Science Foundation of China(Grant Nos.52311530070 and 52004015).
文摘Rock damage significantly affects coupled thermo-hydro-mechanical(THM)behavior in deep geothermal exploitation through changing thermal and hydrological properties of rocks.For this,a thermo-hydro-mechanical-damage(THMD)coupled model was developed to describe the coupling between rock damage and mechanical,fluid flow and heat transfer fields.The model considers rock heterogeneity,and incorporates the Mohr-Coulomb failure criterion and the maximum tensile stress criterion to evaluate shear and tensile damage.This numerical modeling methodology was first verified against analytical solutions and experimental results,and was then used to simulate the THMD coupling behavior in deep geothermal exploitation.A coupled numerical model was set up to simulate the geothermal fluids extraction and re-injection process in a reservoir at 1 km depth over a 7-year period.Rock damage was found to accelerate the propagation of cold fronts away from the injection well,and have a distinct effect on the performance of geothermal exploitation.When the rock damage was considered,the field injectivity increases by 8.4 times,the range of cooled regions increases by 18.6 times,and the vertical deformation changes by 1.2 times after 7 years of geothermal operations,compared to the scenario where it was not considered.Parametric studies have suggested that thermal contraction dominates the rock damage evolution,and that thermal-induced rock damage only occurs at a sufficiently large temperature difference between fluids injected and the reservoir.This work underscores the importance of accurately accounting for the damage effect on reservoir response during fluid injection activities that cause significant cooling of reservoir rocks.
基金supported by the National Natural Science Foundation of China(Grant Nos.T2421001,61922053,62403298)the Natural Science Foundation of Shanghai(Grant No.25ZR1401119)+1 种基金the China Postdoctoral Science Foundation(Grant No.2024M751933)the Shanghai Post-doctoral Excellence Program(Grant No.2023316)。
文摘In this paper,a hierarchical reinforcement learning(HRL)based real-time formation control approach is proposed for heterogeneous aerial-ground agents(HAGAs).Initially,to address the issue of imprecise modeling of HAGAs,a unified heterogeneous chained system model is constructed using the hand-position method.Subsequently,a hierarchical framework is designed:(1)To decouple multi-agent collaborative interactions and individual dynamic rules through hierarchical resolution,which enables controller design to be independent of direct reliance on neighborhood collaborative errors.(2)By adopting a dual-layer framework that separates collaborative topology management from individual control strategies,seamless switching between multiple task scenarios can be achieved simply by reconstructing the collaborative topology of the first layer.Moreover,to overcome the issue of non-asymptotic stability of tracking errors caused by the discount factor in traditional optimal control,a cost function based on the derivative of the tracking error is introduced.This not only addresses the error issue caused by the discount factor but also effectively resolves the problem of the unboundedness of the quadratic cost function.Finally,the efficacy of the proposed algorithm is substantiated through simulation experiments.
