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Hybrid quantum–classical multi-agent decision-making framework based on hierarchical Bayesian networks in the noisy intermediate-scale quantum era
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作者 Hao Shi Chenghao Han +1 位作者 Peng Wang Ming Zhang 《Chinese Physics B》 2025年第12期61-74,共14页
Although quantum Bayesian networks provide a promising paradigm for multi-agent decision-making,their practical application faces two challenges in the noisy intermediate-scale quantum(NISQ)era.Limited qubit resources... Although quantum Bayesian networks provide a promising paradigm for multi-agent decision-making,their practical application faces two challenges in the noisy intermediate-scale quantum(NISQ)era.Limited qubit resources restrict direct application to large-scale inference tasks.Additionally,no quantum methods are currently available for multi-agent collaborative decision-making.To address these,we propose a hybrid quantum–classical multi-agent decision-making framework based on hierarchical Bayesian networks,comprising two novel methods.The first one is a hybrid quantum–classical inference method based on hierarchical Bayesian networks.It decomposes large-scale hierarchical Bayesian networks into modular subnetworks.The inference for each subnetwork can be performed on NISQ devices,and the intermediate results are converted into classical messages for cross-layer transmission.The second one is a multi-agent decision-making method using the variational quantum eigensolver(VQE)in the influence diagram.This method models the collaborative decision-making with the influence diagram and encodes the expected utility of diverse actions into a Hamiltonian and subsequently determines the intra-group optimal action efficiently.Experimental validation on the IonQ quantum simulator demonstrates that the hierarchical method outperforms the non-hierarchical method at the functional inference level,and the VQE method can obtain the optimal strategy exactly at the collaborative decision-making level.Our research not only extends the application of quantum computing to multi-agent decision-making but also provides a practical solution for the NISQ era. 展开更多
关键词 quantum Bayesian networks multi-agent decision-making hybrid quantum–classical algorithms hierarchical Bayesian networks
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A Hierarchical Attention Framework for Business Information Systems:Theoretical Foundation and Proof-of-Concept Implementation
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作者 Sabina-Cristiana Necula Napoleon-Alexandru Sireteanu 《Computers, Materials & Continua》 2026年第2期2055-2088,共34页
Modern business information systems face significant challenges in managing heterogeneous data sources,integrating disparate systems,and providing real-time decision support in complex enterprise environments.Contempo... Modern business information systems face significant challenges in managing heterogeneous data sources,integrating disparate systems,and providing real-time decision support in complex enterprise environments.Contemporary enterprises typically operate 200+interconnected systems,with research indicating that 52% of organizations manage three or more enterprise content management systems,creating information silos that reduce operational efficiency by up to 35%.While attention mechanisms have demonstrated remarkable success in natural language processing and computer vision,their systematic application to business information systems remains largely unexplored.This paper presents the theoretical foundation for a Hierarchical Attention-Based Business Information System(HABIS)framework that applies multi-level attention mechanisms to enterprise environments.We provide a comprehensive mathematical formulation of the framework,analyze its computational complexity,and present a proof-of-concept implementation with simulation-based validation that demonstrates a 42% reduction in crosssystem query latency compared to legacy ERP modules and 70% improvement in prediction accuracy over baseline methods.The theoretical framework introduces four hierarchical attention levels:system-level attention for dynamic weighting of business systems,process-level attention for business process prioritization,data-level attention for critical information selection,and temporal attention for time-sensitive pattern recognition.Our complexity analysis demonstrates that the framework achieves O(n log n)computational complexity for attention computation,making it scalable to large enterprise environments including retail supply chains with 200+system-scale deployments.The proof-of-concept implementation validates the theoretical framework’s feasibility withMSE loss of 0.439 and response times of 0.000120 s per query,demonstrating its potential for addressing key challenges in business information systems.This work establishes a foundation for future empirical research and practical implementation of attention-driven enterprise systems. 展开更多
关键词 Attention mechanisms business information systems theoretical framework enterprise architecture complex systems hierarchical attention
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DECISION-MAKING OF SLICING SCHEME IN FUSED DEPOSITION MODELING PROCESS BASED ON ANALYTICAL HIERARCHICAL PROCESS 被引量:6
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作者 张剑峰 彭安华 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2010年第2期125-130,共6页
Based on analyzing the influences of a slicing scheme on stair-stepping effect, supporting structure, efficiency and deformation, etc. , analytical hierarchical process (AHP) combining with fuzzy synthetic evaluatio... Based on analyzing the influences of a slicing scheme on stair-stepping effect, supporting structure, efficiency and deformation, etc. , analytical hierarchical process (AHP) combining with fuzzy synthetic evaluation is introduced to make decision in slicing schemes for a processing part. The application in determining the slicing scheme for a computer mouse during prototyping shows that the method increases the rationality during decision- making and improves quality and efficiency for the prototyping part. 展开更多
关键词 decision-making fused deposition modeling (FDM) analytical hierarchical process (AHP) slicing scheme
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A hierarchical and role-driven digital twin system with applications to complex chemical process operation
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作者 Xinyu Tao Runjie Yao +3 位作者 Lingyu Zhu Changrui Xie Muqian Zhang Xi Chen 《Chinese Journal of Chemical Engineering》 2026年第1期302-313,共12页
Digital twin technology brings more opportunities and challenges to chemical engineering in both academic and industry.A complex process could have multiple digitalization needs,including simulation,monitoring,operato... Digital twin technology brings more opportunities and challenges to chemical engineering in both academic and industry.A complex process could have multiple digitalization needs,including simulation,monitoring,operator training,etc.;thus,a hierarchical digital twin would be a comprehensive solution to that.In this study,a novel and general framework of the digital twin is proposed for operations in process industry.With the hierarchical structure,the framework can handle various tasks driven by different roles in process industry,including managers,engineers,and operators.To complete these tasks,the framework consists of three modules:OAS(Operation Analysis System),OMS(Operation Monitoring System),and OTS(Operator Training System).Each module focuses on one unique type of demand from the staff,as well as interactions among them enabling efficient data sharing.Based on the hierarchical framework,a digital twin system is applied for one complex industrial nitration process,which successfully enhances the operation efficiency and safety in several industrial scenarios with different demands. 展开更多
关键词 Digital twin hierarchical framework Role-driven Process operation Process modeling&optimization Operator training system
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An integrated decision-making approach to resilience-LCC Bridge network retrofitting using a genetic algorithm-based framework
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作者 Pedram Omidian Naser Khaji Ali Akbar Aghakouchak 《Resilient Cities and Structures》 2025年第1期16-40,共25页
Bridge networks are essential components of civil infrastructure,supporting communities by delivering vital services and facilitating economic activities.However,bridges are vulnerable to natural disasters,particularl... Bridge networks are essential components of civil infrastructure,supporting communities by delivering vital services and facilitating economic activities.However,bridges are vulnerable to natural disasters,particularly earthquakes.To develop an effective disaster management strategy,it is critical to identify reliable,robust,and efficient indicators.In this regard,Life-Cycle Cost(LCC)and Resilience(R)serve as key indicators to assist decision-makers in selecting the most effective disaster risk reduction plans.This study proposes an innova-tive LCC-R optimization framework to identify the most optimal retrofit strategies for bridge networks facing hazardous events during their lifespan.The proposed framework employs both single-and multi-objective opti-mization techniques to identify retrofit strategies that maximize the R index while minimizing the LCC for the under-study bridge networks.The considered retrofit strategies include various options such as different mate-rials(steel,CFRP,and GFRP),thicknesses,arrangements,and timing of retrofitting actions.The first step in the proposed framework involves constructing fragility curves by performing a series of nonlinear time-history incre-mental dynamic analyses for each case.In the subsequent step,the seismic resilience surfaces are calculated using the obtained fragility curves and assuming a recovery function.Next,the LCC is evaluated according to the pro-posed formulation for multiple seismic occurrences,which incorporates the effects of complete and incomplete repair actions resulting from previous multiple seismic events.For optimization purposes,the Non-Dominated Sorting Genetic Algorithm II(NSGA-II)evolutionary algorithm efficiently identifies the Pareto front to represent the optimal set of solutions.The study presents the most effective retrofit strategies for an illustrative bridge network,providing a comprehensive discussion and insights into the resulting tactical approaches.The findings underscore that the methodologies employed lead to logical and actionable retrofit strategies,paving the way for enhanced resilience and cost-effectiveness in bridge network management against seismic hazards. 展开更多
关键词 Bridge network Infrastructures management decision-making framework RESILIENCE Life-cycle cost
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Upcycling FePO_(4) residues from spent lithium-ion batteries toward high-rate LiFePO_(4) cathode by constructing hierarchical conductive frameworks
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作者 Da Guo Chunxian Xing +7 位作者 Long Chen Zhuoli Yang Jiawei Huang Guangren Wang Tao Liu Mengdan Jiang Peng Wang Linfeng Fei 《Journal of Energy Chemistry》 2025年第11期571-580,I0014,共11页
A notable retiring wave for lithium iron phosphate(LiFePO_(4),LFP)-based lithium-ion batteries(LIBs)is expected in the coming years,which urges the establishment of complete and eco-friendly recycling chains.Currently... A notable retiring wave for lithium iron phosphate(LiFePO_(4),LFP)-based lithium-ion batteries(LIBs)is expected in the coming years,which urges the establishment of complete and eco-friendly recycling chains.Currently,the industrial practice for these degraded LFP materials heavily relies on the hydrometallurgical strategies,which aim for the selective leaching of valuable Li element;this,however,leads to the accumulation of FePO_(4)by-product as a waste,which is neither economical nor sustainable.Considering the increasing demand on performance for next-generation LFP cathode materials,herein,we demonstrate a facile,green,and economic method to upcycle FePO_(4)residues from spent LIBs into high-performance LFP materials for direct reusages.The upcycling protocol involves simultaneous structural restoration of LFP lattices and hierarchical assembly of graphene-based conductive frameworks.As a result,the upcycled LFP cathode material delivers exceptional rate performance(discharge capacity of 125.6 mA h g^(-1)at 5 C or 93.6 mA h g^(-1)at 15 C)and cycling stability under high-rate conditions(capacity retention of 99.5%after 300 cycles at 1 C or 96.7%after 1000 cycles at 5 C).Moreover,the electrochemical performance is largely maintained at low temperatures.The upcycling strategy sheds light on the closed-loop development of LIB industry. 展开更多
关键词 Spent lithium-ion batteries Degraded cathode materials Lithium iron phosphate hierarchical conductive frameworks Direct upcycling
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Study on group air to ground attack-defends hierarchical dynamic decision-making 被引量:1
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作者 Zhang Li Zhang An Zhang Yongfang Shi Zhifu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2007年第3期540-544,共5页
As to oppositional, multi-objective and hierarchical characteristic of air formation to ground attackdefends campaign, and using dynamic space state model of military campaign, this article establishes a principal and... As to oppositional, multi-objective and hierarchical characteristic of air formation to ground attackdefends campaign, and using dynamic space state model of military campaign, this article establishes a principal and subordinate hierarchical interactive decision-making way, the Nash-Stackelberg-Nash model, to solve the problems in military operation, and find out the associated best strategy in hierarchical dynamic decision-making. The simulating result indicate that when applying the model to air formation to ground attack-defends decision-making system, it can solve the problems of two hierarchies, dynamic oppositional decision-making favorably, and reach preferable effect in battle. It proves that the model can provide an effective way for analyzing a battle, 展开更多
关键词 dynamic game theory Nash-Stackelberg-Nash strategy hierarchical decision-making attack-defends antagonize.
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Hierarchical Metal-Organic Frameworks with Macroporosity:Synthesis, Achievements,and Challenges 被引量:11
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作者 Huan VDoan Harina Amer Hamzah +2 位作者 Prasanth Karikkethu Prabhakaran Chiara Petrillo Valeska PTing 《Nano-Micro Letters》 SCIE EI CAS CSCD 2019年第3期281-313,共33页
Introduction of multiple pore size regimes into metalorganic frameworks(MOFs)to form hierarchical porous structures can lead to improved performance of the material in various applications.In many cases,where interact... Introduction of multiple pore size regimes into metalorganic frameworks(MOFs)to form hierarchical porous structures can lead to improved performance of the material in various applications.In many cases,where interactions with bulky molecules are involved,enlarging the pore size of typically microporous MOF adsorbents or MOF catalysts is crucial for enhancing both mass transfer and molecular accessibility.In this review,we examine the range of synthetic strategies which have been reported thus far to prepare hierarchical MOFs or MOF composites with added macroporosity.These fabrication techniques can be either pre-or post-synthetic and include using hard or soft structural template agents,defect formation,routes involving supercritical CO2,and 3D printing.We also discuss potential applications and some of the challenges involved with current techniques,which must be addressed if any of these approaches are to be taken forward for industrial applications. 展开更多
关键词 METAL-ORGANIC frameworks hierarchical MACROPOROUS Composites
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Mission decision-making method of multi-aircraft cooperatively attacking multi-target based on game theoretic framework 被引量:23
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作者 Yao Zongxin Li Ming +1 位作者 Chen Zongji Zhou Rui 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2016年第6期1685-1694,共10页
Coordinated mission decision-making is one of the core steps to effectively exploit the capabilities of cooperative attack of multiple aircrafts. However, the situational assessment is an essential base to realize the... Coordinated mission decision-making is one of the core steps to effectively exploit the capabilities of cooperative attack of multiple aircrafts. However, the situational assessment is an essential base to realize the mission decision-making. Therefore, in this paper, we develop a mission decision-making method of multi-aircraft cooperatively attacking multi-target based on situational assessment. We have studied the situational assessment mathematical model based on the Dempster-Shafer(D-S) evidence theory and the mission decision-making mathematical model based on the game theory. The proposed mission decision-making method of antagonized airfight is validated by some simulation examples of a swarm of unmanned combat aerial vehicles(UCAVs)that carry out the mission of the suppressing of enemy air defenses(SEAD). 展开更多
关键词 Antagonized airfight D-S evidence theory Fuzzy mapping function Game theoretic framework Mission decision-making Multi-aircraft coordination Situational assessment
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Recent advances in the synthesis of nanoscale hierarchically porous metal–organic frameworks 被引量:10
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作者 Chongxiong Duan Kuan Liang +8 位作者 Zena Zhang Jingjing Li Ting Chen Daofei Lv Libo Li Le Kang Kai Wang Han Hu Hongxia Xi 《Nano Materials Science》 EI CAS CSCD 2022年第4期351-365,共15页
Nanoscale hierarchically porous metal–organic frameworks(NHP-MOFs)have received unprecedented attention in many fields owing to their integration of the strengths of nanoscale size(<1μm)and hierarchical porous st... Nanoscale hierarchically porous metal–organic frameworks(NHP-MOFs)have received unprecedented attention in many fields owing to their integration of the strengths of nanoscale size(<1μm)and hierarchical porous structure(micro-,meso-and/or macro-pores)of MOFs.This review focuses on recent advances in the main synthetic strategies for NHP-MOFs based on different metal ions(e.g.,Cu,Fe,Co,Zn,Al,Zr,and Cr),including the template method,composite technology,post-synthetic modification,in situ growth and the grind method.In addition,the mechanisms of synthesis,regulation techniques and the advantages and disadvantages of various methods are discussed.Finally,the challenges and prospects of the commercialisation of promising NHP-MOFs are also presented.The purpose of this review is to provide a road map for future design and development of NHP-MOFs for practical application. 展开更多
关键词 Metal–organic frameworks NANOSCALE hierarchically porous structure Synthesis strategies
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Metal–organic framework derived hierarchical porous TiO_2 nanopills as a super stable anode for Na-ion batteries 被引量:1
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作者 Huan Li Zhiguo Zhang +3 位作者 Xiao Huang Tongbin Lan Mingdeng Wei Tingli Ma 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2017年第4期667-672,共6页
Hierarchical porous TiOnanopills were synthesized using a titanium metal-organic framework MIL-125(Ti) as precursor. The as-synthesized TiOnanopills owned a large specific surface area of 102 m/g and unique porous s... Hierarchical porous TiOnanopills were synthesized using a titanium metal-organic framework MIL-125(Ti) as precursor. The as-synthesized TiOnanopills owned a large specific surface area of 102 m/g and unique porous structure. Furthermore, the obtained TiOnanopills were applied as anode materials for Na-ion batteries for the first time. The as-synthesized TiOnanopills achieved a high discharge capacity of 196.4 m Ah/g at a current density of 0.1 A/g. A discharge capacity of 115.9 m Ah/g was obtained at a high current density of 0.5 A/g and the capacity retention was remained as high as 90% even after 3000 cycles. The excellent electrochemical performance can be attributed to its unique hierarchical porous feature. 展开更多
关键词 hierarchical porous structure TiO2 nanopills Metal–organic framework Na-ion batteries
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Water-based synthesis of nanoscale hierarchical metal-organic frameworks:Boosting adsorption and catalytic performance 被引量:1
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作者 Yi Yu Zewei Liu +3 位作者 Xiaofei Chen Shujun Liu Chongxiong Duan Hongxia Xi 《Nano Materials Science》 EI CAS CSCD 2023年第4期361-368,共8页
The combination of nano sizes,large pore sizes and green synthesis is recognized as one of the most crucial and challenging problems in constructing metal-organic frameworks(MOFs).Herein,a water-based strategy is prop... The combination of nano sizes,large pore sizes and green synthesis is recognized as one of the most crucial and challenging problems in constructing metal-organic frameworks(MOFs).Herein,a water-based strategy is proposed for the synthesis of nanoscale hierarchical MOFs(NH-MOFs)with high crystallinity and excellent stability.This approach allows the morphology and porosity of MOFs to be fine tuned,thereby enabling the nanoscale crystal generation and a well-defined hierarchical system.The aqueous solution facilitates rapid nucleation kinetics,and the introduced modulator acts as a deprotonation agent to accelerate the deprotonation of the organic ligand as well as a structure-directing agent(SDA)to guide the formation of hierarchical networks.The assynthesized NH-MOFs(NH-ZIF-67)were assessed as efficient adsorbents and heterogeneous catalysts to facilitate the diffusion of vip molecules,outperforming the parent microZIF-67.This study focuses on understanding the NH-MOF growth rules,which could allow tailor-designing NH-MOFs for various functions. 展开更多
关键词 Nanoscale hierarchical metal-organic framework Water-based synthesis Volatile organic compounds Olefins oxidation
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Ultra-stable and High-rate Lithium Ion Batteries Based on Metal-organic Framework-derived ln2O3 Nanocrystals/Hierarchically Porous Nitrogen-doped Carbon Anode 被引量:5
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作者 Hanjiao Xu Lei Wang +7 位作者 Jiang Zhong Tao Wang Jinhui Cao Yaya Wang Xiuqi Li Huilong Fei Jian Zhu Xidong Duan 《Energy & Environmental Materials》 2020年第2期177-185,共9页
Exploring electrode materials with attractive specific capacity and prominent cyclic durability is of the essence for promoting lithium ion batteries(LIBs).In2O3 has shown an extraordinary promise for LIBs with advant... Exploring electrode materials with attractive specific capacity and prominent cyclic durability is of the essence for promoting lithium ion batteries(LIBs).In2O3 has shown an extraordinary promise for LIBs with advantageous gravimetric capacity(theoretically 965 mA h g-1) and low working voltage.However,In2O3 still suffers from the inherent weaknesses of metal oxides in practical application,especially low conductivity and incorrigible volume expansion upon the cycling process.Here,we demonstrate the architecture of metal-organic framework(MOF)-derived In2O3 nanocrystals/hierarchically porous nitrogen-doped carbon composite(In2O3/HPNC) for ultra-stable LIBs anode.This hierarchically porous structure(micro/meso/macro-pores) with nitrogen doping not only ensures exceptional mechanical strength and accommodates the volume expansion of In2O3 nanocrystals,but also offers electrons and lithium ions efficient interpenetrating pathways to migrate rapidly during charge/discharge processes.Thus,In2O3/HPNC exhibits excellent cyclic stability with a high specific capacity of 623 mA h g-1 over2000 cycles at 1000 mA g-1,corresponding to an ultra-low specific capacity decay of 0.017% per cycle(the best among the ln203-based anode for LIBs),and outstanding rate performance,suggesting a critical step toward achieving long-life and high-rate LIBs in practical devices. 展开更多
关键词 hierarchically porous structure In203 nanocrystals metal-organic frameworks nitrogen-doping carbon ultra-stable lithium ion batteries
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Surface carbon layer controllable Ni_(3)Fe particles confined in hierarchical N-doped carbon framework boosting oxygen evolution reaction 被引量:14
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作者 Zhijuan Li Xiaodong Wu +5 位作者 Xian Jiang Binbin Shen Zhishun Teng Dongmei Sun Gengtao Fu Yawen Tang 《Advanced Powder Materials》 2022年第2期73-83,共11页
Developing high-efficiency and low-cost catalysts towards oxygen evolution reaction(OER)is extremely important for overall water splitting and rechargeable metal-air batteries.Herein we propose a promising organometal... Developing high-efficiency and low-cost catalysts towards oxygen evolution reaction(OER)is extremely important for overall water splitting and rechargeable metal-air batteries.Herein we propose a promising organometallic coordination polymer(OCP)induced strategy to construct hierarchical N-doped carbon framework with NiFe nanoparticles encapsulated inside(NxFe@N-C)as a highly active and stable OER catalyst.The synthesis of OCP precursor depends on the unique molecular structure of iminodiacetonitrile(IDAN),which can coordinate with metal ions to form Ni2Fe(CN)6 with prussian blue analogs(PBA)structure.Unlike previous PBA-induced methods,the thickness of the carbon layer covering the surface of the metal core can be well controlled during the pyrolysis through adjusting the amount of IDAN,which builds a wonderful bridge for investigating the relationship between carbon layer thickness and catalytic performance.Both the experimental characterizations and theoretical studies validate that a suitable carbon layers thickness leads to optimal OER activity and stability.By optimizing the structure and composition,the optimized Ni_(3)Fe@N-C with hierarchical framework exhibits the low overpotentials(260 mV at 10 mA cm^(-2);320 mV at 50 mA cm^(-2)),improved kinetics(79 mV dec^(-1)),and robust long-term stability,which exceeds those of benchmark RuO_(2). 展开更多
关键词 Iminodiacetonitrile Organometallic coordination polymer Ni_(3)Fe@N-carbon hierarchical framework Oxygen evolution reaction
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A Unified Parametric Divergence Operator for Fermatean Fuzzy Environment and Its Applications in Machine Learning and Intelligent Decision-Making
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作者 Zhe Liu Sijia Zhu +5 位作者 Yulong Huang Tapan Senapati Xiangyu Li Wulfran Fendzi Mbasso Himanshu Dhumras Mehdi Hosseinzadeh 《Computer Modeling in Engineering & Sciences》 2025年第11期2157-2188,共32页
Uncertainty and ambiguity are pervasive in real-world intelligent systems,necessitating advanced mathematical frameworks for effective modeling and analysis.Fermatean fuzzy sets(FFSs),as a recent extension of classica... Uncertainty and ambiguity are pervasive in real-world intelligent systems,necessitating advanced mathematical frameworks for effective modeling and analysis.Fermatean fuzzy sets(FFSs),as a recent extension of classical fuzzy theory,provide enhanced flexibility for representing complex uncertainty.In this paper,we propose a unified parametric divergence operator for FFSs,which comprehensively captures the interplay among membership,nonmembership,and hesitation degrees.The proposed operator is rigorously analyzed with respect to key mathematical properties,including non-negativity,non-degeneracy,and symmetry.Notably,several well-known divergence operators,such as Jensen-Shannon divergence,Hellinger distance,andχ2-divergence,are shown to be special cases within our unified framework.Extensive experiments on pattern classification,hierarchical clustering,and multiattribute decision-making tasks demonstrate the competitive performance and stability of the proposed operator.These results confirm both the theoretical significance and practical value of our method for advanced fuzzy information processing in machine learning and intelligent decision-making. 展开更多
关键词 Fermatean fuzzy sets divergence operator pattern classification hierarchical clustering multiattribute decision-making
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MOFs-derived flower-like cobalt@carbon multiscale hierarchical composites with effective microwave absorption in the low frequency range
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作者 Jiali Guan Hongmei Li +7 位作者 Jiannan Ren Wenhui Qiu Qi Li Zhufeng He Mingwei Zhu Wei Li Nan Jia Shaowei Lu 《International Journal of Minerals,Metallurgy and Materials》 2025年第4期954-963,共10页
The wave-absorbing materials are kinds of special electromagnetic functional materials and have been widely used in electromagnetic pollution control and military fields.In-situ integrated hierarchical structure const... The wave-absorbing materials are kinds of special electromagnetic functional materials and have been widely used in electromagnetic pollution control and military fields.In-situ integrated hierarchical structure construction is thought as a promising route to improve the microwave absorption performance of the materials.In the present work,layer-structured Co-metal-organic frameworks(Co-MOFs)precursors were grown in-situ on the surface of carbon fibers with the hydrothermal method.After annealed at 500℃ under Ar atmosphere,a novel multiscale hierarchical composite(Co@C/CF)was obtained with the support of carbon fibers,keeping the flower-like structure.Scanning electron microscope,transmission electron microscope,X-ray diffraction,Raman,and X-ray photoelectron spectroscopy were performed to analyze the microstructure and composition of the hierarchical structure,and the microwave absorption performance of the Co@C/CF composites were investigated.The results showed that the growth of the flower-like structure on the surface of carbon fiber was closely related to the metal-to-ligand ratio.The optimized Co@C/CF flower-like composites achieved the best reflection loss of−55.7 dB in the low frequency band of 6–8 GHz at the thickness of 2.8 mm,with the corresponding effective absorption bandwidth(EAB)of 2.1 GHz.The EAB of 3.24 GHz was achieved in the high frequency range of 12–16 GHz when the thickness was 1.5 mm.The excellent microwave absorption performance was ascribed to the introduction of magnetic components and the construction of the unique structure.The flower-like structure not only balanced the impedance of the fibers themselves,but also extended the propagation path of the microwave and then increased the multiple reflection losses.This work provides a convenient method for the design and development of wave-absorbing composites with in-situ integrated structure. 展开更多
关键词 carbon fiber metal-organic framework hierarchical structure flower-like composite microwave absorption
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Analytical solution for the stress field of hierarchical defects:multiscale framework and applications
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作者 Baijian WU Sheng ZHOU Zhaoxia LI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2021年第2期183-208,共26页
Hierarchical defects are defined as adjacent defects at different length scales.Involved are the two scales where the stress field distribution is interrelated.Based on the complex variable method and conformal mappin... Hierarchical defects are defined as adjacent defects at different length scales.Involved are the two scales where the stress field distribution is interrelated.Based on the complex variable method and conformal mapping,a multiscale framework for solving the problems of hierarchical defects is formulated.The separated representations of mapping function,the governing equations of potentials,and the stress field are subsequently obtained.The proposed multiscale framework can be used to solve a variety of simplified engineering problems.The case in point is the analytical solution of a macroscopic elliptic hole with a microscopic circular edge defect.The results indicate that the microscopic defect aggregates the stress concentration on the macroscopic defect and likely leads to global propagation and rupture.Multiple micro-defects have interactive effects on the distribution of the stress field.The level of stress concentration may be reduced by the coalescence of micro-defects.This work provides a unified method to analytically investigate the influence of edge micro-defects within the scope of multiscale hierarchy.The formulated multiscale approach can also be potentially applied to materials with hierarchical defects,such as additive manufacturing and bio-inspired materials. 展开更多
关键词 hierarchical defect stress field multiscale framework scale separation complex variable method elliptic crack edge defect
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Enhanced stability of highly-dispersed copper catalyst supported by hierarchically porous carbon for long term selective hydrogenation 被引量:4
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作者 Nian Hu Xiao-Yun Li +7 位作者 Si-Ming Liu Zhao Wang Xiao-Ke He Yue-Xin Hou Yu-Xiang Wang Zhao Deng Li-Hua Chen Bao-Lian Su 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第7期1081-1090,共10页
Copper based catalysts have high potential for the substituent of noble-metal based catalysts as their high selectivity and moderate activity for selective hydrogenation reaction;however,achieving further high catalyt... Copper based catalysts have high potential for the substituent of noble-metal based catalysts as their high selectivity and moderate activity for selective hydrogenation reaction;however,achieving further high catalytic stability is very difficult.In this work,the carbonization process of Cu-based organic frameworks was explored for the synthesis of highly-dispersed Cu supported by hierarchically porous carbon with high catalytic performance for selective hydrogenation of 1,3-butadiene.The porous hierarchy of carbon support and the dispersion of copper nanoparticles can be precisely tuned by controlling the carbonization process.The resultant catalyst carbonized at 600°C exhibits a rather low reaction temperature at 75°C for 100%butadiene conversion with 100%selectivity to butenes,due to its reasonable porous hierarchy and highly-dispersed copper sites.More importantly,unprecedentedly stability of the corresponding Cu catalyst was firstly observed for selective 1,3-butadiene hydrogenation,with both 100%butadiene conversion and 100%butenes selectivity over 120 h of reaction at 75°C.This study verifies that a simply control the carbonization process of metal organic frameworks can be an effective way to obtain Cu-based catalysts with superior catalytic performance for selective hydrogenation reaction. 展开更多
关键词 hierarchically porous structure CATALYST Cu/C Selective hydrogenation Metal organic frameworks
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Hierarchically porous Co@N-doped carbon fiber assembled by MOF-derived hollow polyhedrons enables effective electronic/mass transport:An advanced 1D oxygen reduction catalyst for Zn-air battery 被引量:4
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作者 Yifei Zhang Quanfeng He +4 位作者 Zihao Chen Yuqing Chi Junwei Sun Ding Yuan Lixue Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第1期117-126,I0004,共11页
Developing advanced oxygen reduction reaction(ORR)electrocatalysts with rapid mass/electron transport as well as conducting relevant kinetics investigations is essential for energy technologies,but both still face ong... Developing advanced oxygen reduction reaction(ORR)electrocatalysts with rapid mass/electron transport as well as conducting relevant kinetics investigations is essential for energy technologies,but both still face ongoing challenges.Herein,a facile approach was reported for achieving the highly dispersed Co nanoparticles anchored hierarchically porous N-doped carbon fibers(Co@N-HPCFs),which were assembled by core-shell MOFs-derived hollow polyhedrons.Notably,the unique one-dimensional(1D)carbon fibers with hierarchical porosity can effectively improve the exposure of active sites and facilitate the electron transfer and mass transfer,resulting in the enhanced reaction kinetics.As a result,the ORR performance of the optimal Co@N-HPCF catalysts remarkably outperforms that of commercial Pt/C in alkaline solution,reaching a limited diffusion current density(J)of 5.85 m A cm^(-2)and a half-wave potential(E_(1/2))of 0.831 V.Particularly,the prepared Co@N-HPCF catalysts can be used as an excellent air-cathode for liquid/solid-state Zn-air batteries,exhibiting great potentiality in portable/wearable energy devices.Furthermore,the reaction kinetic during ORR process is deeply explored by finite element simulation,so as to intuitively grasp the kinetic control region,diffusion control region,and mixing control region of the ORR process,and accurately obtain the relevant kinetic parameters.This work offers an effective strategy and a reliable theoretical basis for the engineering of first-class ORR electrocatalysts with fast electronic/mass transport. 展开更多
关键词 Oxygen reduction catalyst Metal-organic frameworks Carbon nanofiber hierarchically porous structure Diffusion kinetics Zn-air battery
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Weaving 3D highly conductive hierarchically interconnected nanoporous web by threading MOF crystals onto multi walled carbon nanotubes for high performance Li-Se battery 被引量:4
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作者 Chao Li Yingying Wang +7 位作者 Hongyan Li Jing Liu Jianping Song Luca Fusaro Zhi-Yi Hu Yanxin Chen Yu Li Bao-Lian Su 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第8期396-404,I0009,共10页
Lithium-selenium(Li-Se)battery has attracted growing attention.Nevertheless,its practical application is still impeded by the shuttle effect of the formed polyselenides.Herein,we report in-situ hydrothermal weaving th... Lithium-selenium(Li-Se)battery has attracted growing attention.Nevertheless,its practical application is still impeded by the shuttle effect of the formed polyselenides.Herein,we report in-situ hydrothermal weaving the three-dimensional(3 D)highly conductive hierarchically interconnected nanoporous web by threading microporous metal organic framework MIL-68(Al)crystals onto multi-walled carbon nanotubes(MWCNTs).Such 3 D hierarchically nanoporous web(3 D MIL-68(Al)@MWCNTs web)with a very high surface area,a large amount of micropores,electrical conductivity and elasticity strongly traps the soluble polyselenides during the electrochemical reaction and significantly facilitates lithium ion diffusion and electron transportation.Molecular dynamic calculation confirmed the strong affinity of MIL-68(Al)for the adsorption of polyselenides,quite suitable for Li-Se battery.Their hexahedral channels(1.56 nm)are more efficient for the confinement of polyselenides and for the diffusion of electrolytes compared to their smaller triangular channels(0.63 nm).All these excellent characteristics of 3 D MIL-68(Al)@MWCNTs web with suitable confinement of a large amount of selenium and the conductive linkage between MIL-68(Al)host by MWCNTs result in a high capacity of 453 m Ah/g at 0.2 C with 99.5%coulombic efficiency after 200 cycles with significantly improved cycle stability and rate performance.The 3 D MIL-68(Al)@MWCNTs web presents a good performance in Li-Se battery in term of the specific capacity and cycling stability and also in terms of rate performance compared with all the metal-organic framework(MOF)based or MOF derived porous carbons used in Li-Se battery. 展开更多
关键词 Lithium selenium battery Selenium confinement 3D hierarchically nanoporous web Metal-organic framework(MOF) Multi walled carbon nanotubes
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