Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully construct...Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully constructed by coordinatively assembling the semi-rigid multidentate ligand 5-(1-carboxyethoxy)isophthalic acid(H₃CIA)with the Nheterocyclic ligands 1,4-di(4H-1,2,4-triazol-4-yl)benzene(1,4-dtb)and 1,4-di(1H-imidazol-1-yl)benzene(1,4-dib),respectively,around Co^(2+)ions.Single-crystal X-ray diffraction analysis revealed that in both complexes HU23 and HU24,the CIA^(3-)anions adopt aκ^(7)-coordination mode,bridging six Co^(2+)ions via their five carboxylate oxygen atoms and one ether oxygen atom.This linkage forms tetranuclear[Co4(μ3-OH)2]^(6+)units.These Co-oxo cluster units were interconnected by CIA^(3-)anions to assemble into 2D kgd-type structures featuring a 3,6-connected topology.The 2D layers were further connected by 1,4-dtb and 1,4-dib,resulting in 3D pillar-layered frameworks for HU23 and HU24.Notably,despite the similar configurations of 1,4-dtb and 1,4-dib,differences in their coordination spatial orientations lead to topological divergence in the 3D frameworks of HU23 and HU24.Topological analysis indicates that the frameworks of HU23 and HU24 can be simplified into a 3,10-connected net(point symbol:(4^(10).6^(3).8^(2))(4^(3))_(2))and a 3,8-connected tfz-d net(point symbol:(4^(3))_(2)((4^(6).6^(18).8^(4)))),respectively.This structural differentiation confirms the precise regulatory role of ligands on the topology of metal-organic frameworks.Moreover,the ultraviolet-visible absorption spectra confirmed that HU23 and HU24 have strong absorption capabilities for ultraviolet and visible light.According to the Kubelka-Munk method,their bandwidths were 2.15 and 2.08 eV,respectively,which are consistent with those of typical semiconductor materials.Variable-temperature magnetic susceptibility measurements(2-300 K)revealed significant antiferromagnetic coupling in both complexes,with their effective magnetic moments decreasing markedly as the temperature lowered.CCDC:2457554,HU23;2457553,HU24.展开更多
The increasing intelligence of power systems is transforming distribution networks into Cyber-Physical Distribution Systems(CPDS).While enabling advanced functionalities,the tight interdependence between cyber and phy...The increasing intelligence of power systems is transforming distribution networks into Cyber-Physical Distribution Systems(CPDS).While enabling advanced functionalities,the tight interdependence between cyber and physical layers introduces significant security challenges and amplifies operational risks.To address these critical issues,this paper proposes a comprehensive risk assessment framework that explicitly incorporates the physical dependence of information systems.A Bayesian attack graph is employed to quantitatively evaluate the likelihood of successful cyber attacks.By analyzing the critical scenario of fault current path misjudgment,we define novel system-level and node-level risk coupling indices to preciselymeasure the cascading impacts across cyber and physical domains.Furthermore,an attack-responsive power recovery optimization model is established,integrating DistFlowbased physical constraints and sophisticated modeling of information-dependent interference.To enhance resilience against varying attack scenarios,a defense resource allocation model is constructed,where the complex Mixed-Integer Nonlinear Programming(MINLP)problem is efficiently linearized into a Mixed-Integer Linear Programming(MILP)formulation.Finally,to mitigate the impact of targeted attacks,the optimal deployment of terminal defense resources is determined using a Stackelberg game-theoretic approach,aiming to minimize overall system risk.The robustness and effectiveness of the proposed integrated framework are rigorously validated through extensive simulations under diverse attack intensities and defense resource constraints.展开更多
The preparation of carbon-based electromagnetic wave(EMW)absorbers possessing thin matching thickness,wide absorption bandwidth,strong absorption intensity,and low filling ratio remains a huge challenge.Metal-organic ...The preparation of carbon-based electromagnetic wave(EMW)absorbers possessing thin matching thickness,wide absorption bandwidth,strong absorption intensity,and low filling ratio remains a huge challenge.Metal-organic frameworks(MOFs)are ideal self-sacrificing templates for the construction of carbon-based EMW absorbers.In this work,bimetallic FeMn-MOF-derived MnFe_(2)O_(4)/C/graphene composites were fabricated via a two-step route of solvothermal reaction and the following pyrolysis treatment.The results re-veal the evolution of the microscopic morphology of carbon skeletons from loofah-like to octahedral and then to polyhedron and pomegran-ate after the adjustment of the Fe^(3+)to Mn^(2+)molar ratio.Furthermore,at the Fe^(3+)to Mn^(2+)molar ratio of 2:1,the obtained MnFe_(2)O_(4)/C/graphene composite exhibited the highest EMW absorption capacity.Specifically,a minimum reflection loss of-72.7 dB and a max-imum effective absorption bandwidth of 5.1 GHz were achieved at a low filling ratio of 10wt%.In addition,the possible EMW absorp-tion mechanism of MnFe_(2)O_(4)/C/graphene composites was proposed.Therefore,the results of this work will contribute to the construction of broadband and efficient carbon-based EMW absorbers derived from MOFs.展开更多
A thickness-controllable method for preparing metal-organic framework hollow nanofiowers on magnetic cores(Fe_(3)O_(4)@MOFs HFs)was demonstrated for the first time.The petal of magnetic core with hollow nanofiower str...A thickness-controllable method for preparing metal-organic framework hollow nanofiowers on magnetic cores(Fe_(3)O_(4)@MOFs HFs)was demonstrated for the first time.The petal of magnetic core with hollow nanofiower structure served as medium for assembling Ui O-66-NH_(2)shell with different thickness.To further improve its performance,Zr^(4+)was immobilized on the surface of Fe_(3)O_(4)@Ui O-66-NH_(2).Compared with conventional Fe_(3)O_(4)@Ui O-66-NH_(2)-Zr^(4+)nanospheres,the Fe_(3)O_(4)@Ui O-66-NH2-Zr4+HFs showed increased enrichment performance for phosphopeptides.The Fe_(3)O_(4)@Ui O-66-NH2-Zr4+HFs served as an attractive restricted-access adsorption material exhibited good selectivity(m_(β-casein):m_(BSA)=1:1000),high sensitivity(1.0 fmol)and excellent size-exclusion effect(m)((β-casein digests):m_(BSA)=1:200).Furthermore,the Fe_(3)O_(4)@Ui O-66-NH_(2)-Zr^(4+)HFs was successfully applied to the specific capture of ultratrace phosphopeptide from complex biological samples,revealing the great potential for the identification and analysis of trace phosphopeptides in clinical analysis.This work can be easily extended to the fabrication of diverse mag-MOF HFs with multifunctional and easy to post-modify properties,and open up a new avenue for the design and construction of new MOFs material.展开更多
Carbon-based sponge materials have attracted massive attention as electromagnetic wave(EMW)absorber candidates due to their lightweight and excellent electromagnetic(EM)attenuation capability.However,the high cost,com...Carbon-based sponge materials have attracted massive attention as electromagnetic wave(EMW)absorber candidates due to their lightweight and excellent electromagnetic(EM)attenuation capability.However,the high cost,complex fabrication process and limited EMW absorption bandwidth restrict their application.Herein,a hierarchical threedimensional(3D)cotton derived carbon fibers coated with core–shell structure Fe Ni nanoparticle@porous carbon(CCF/Fe Ni@PC)from MOF precursor were successfully constructed by coprecipitation and one-step pyrolysis methods.By regulating carbonization temperature,optimizing the electromagnetic parameters,outstanding electromagnetic absorption(EMA)performance was achieved.The CCF@Fe Ni/PC synthesized at 900℃demonstrates a-64.5 d B minimum reflection loss(RL_(min))at 15.39 GHz,and the effective absorption bandwidth(EAB)is 5.08 GHz when the thickness is only1.9 mm.Notably,the maximum EAB(EAB_(max))was extended8.18 GHz at 2.96 mm for Fe Ni-800.The excellent microwave absorption performance is attributed to the synergistic effect of enhanced dielectric loss and magnetic loss,good impedance matching as well as hierarchical multiple scattering and reflection of EMWs.The obtained CCF@Fe Ni/PC composites provide a novel and promising strategy for constructing lightweight low-cost efficient microwave absorption materials.展开更多
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
While single-ion conducting solid polymer electrolytes(SPE)offer inherent safety advantages for lithium metal batteries,their practical implementation is hindered by inadequate ionic transport and unstable electrode i...While single-ion conducting solid polymer electrolytes(SPE)offer inherent safety advantages for lithium metal batteries,their practical implementation is hindered by inadequate ionic transport and unstable electrode interfaces.We presented a breakthrough single-ion SPE system through molecular engineering of lithium-enriched porous aromatic frameworks(PAF-228-Li)integrated with poly(ethylene oxide),achieving exceptional ion conduction and interfacial stability.The precisely designed PAF-228-Li architecture established continuous 3D Li+transport pathways through its intrinsic porous channels and surface conduction sites,synergistically enhanced by PVDF-HFP nanofiber networks.This unique design enabled record-high ionic conductivities of 5.48×10^(-4)S cm^(-1)at 30℃and 3.4×10^(-4)S cm^(-1)at-20℃—among the best reported for PEO-based SPEs.The electrolyte spontaneously formed a selflimiting SEI rich in LiF/Li3N,effectively suppressing dendritic growth while enabling unprecedented cycling stability:Li||LiFePO4cells maintain 83.7%capacity over 700 cycles(30℃)and deliver 104.4 mA h g^(-1)after 1100 cycles at-20℃.Practical viability is further demonstrated in pouch cell configurations with stable operation at 30℃.This work pioneers a materials paradigm combining porous framework engineering with polymer electrolyte design,establishing new researching direction for low-temperature compatible,dendrite-resistant solid-state batteries.展开更多
Metal–organic frameworks(MOFs)hold great potential for gas separation and storage,and graph neural networks have proven to be a powerful tool for exploring material structure–property relationships and discovering n...Metal–organic frameworks(MOFs)hold great potential for gas separation and storage,and graph neural networks have proven to be a powerful tool for exploring material structure–property relationships and discovering new materials.Unlike traditional molecular graphs,crystal graphs require consideration of periodic invariance and modes.In addition,MOF structures such as covalent bonds,functional groups,and global structures impact adsorption performance in different ways.However,redundant atomic interactions can disrupt training accuracy,potentially leading to overfitting.In this paper,we propose a multi-scale crystal graph for describing periodic crystal structures,modeling interatomic interactions at different scales while preserving periodicity invariance.We also propose a multi-head attention crystal graph network in multi-scale graphs(MHACGN-MS),which learns structural characteristics by focusing on interatomic interactions at different scales,thereby reducing interference from redundant interactions.Using MOF adsorption for gases as an example,we demonstrate that MHACGN-MS outperforms traditional graph neural networks in predicting multi-component gas adsorption.We also visualize attention scores to validate effective learning and demonstrate the model’s interpretability.展开更多
Detecting surface defects on unused rails is crucial for evaluating rail quality and durability to ensure the safety of rail transportation.However,existing detection methods often struggle with challenges such as com...Detecting surface defects on unused rails is crucial for evaluating rail quality and durability to ensure the safety of rail transportation.However,existing detection methods often struggle with challenges such as complex defect morphology,texture similarity,and fuzzy edges,leading to poor accuracy and missed detections.In order to resolve these problems,we propose MSCM-Net(Multi-Scale Cross-Modal Network),a multiscale cross-modal framework focused on detecting rail surface defects.MSCM-Net introduces an attention mechanism to dynamically weight the fusion of RGB and depth maps,effectively capturing and enhancing features at different scales for each modality.To further enrich feature representation and improve edge detection in blurred areas,we propose a multi-scale void fusion module that integrates multi-scale feature information.To improve cross-modal feature fusion,we develop a cross-enhanced fusion module that transfers fused features between layers to incorporate interlayer information.We also introduce a multimodal feature integration module,which merges modality-specific features from separate decoders into a shared decoder,enhancing detection by leveraging richer complementary information.Finally,we validate MSCM-Net on the NEU RSDDS-AUG RGB-depth dataset,comparing it against 12 leading methods,and the results show that MSCM-Net achieves superior performance on all metrics.展开更多
The arbitrary discharge of tetracycline(TC)residuals has seriously influenced the ecosystem and human health.Laccase(Lac)-based biodegradation technology is considered a more effective way to remove TC due to its high...The arbitrary discharge of tetracycline(TC)residuals has seriously influenced the ecosystem and human health.Laccase(Lac)-based biodegradation technology is considered a more effective way to remove TC due to its high catalytic efficiency and less by-product.Nevertheless,free Lac suffers from poor stability,easy inactivation and difficult recovery,restricting its application.Immobilization of Lac is considered an efficient strategy for addressing these obstacles.In this study,a magnetic metal-organic framework of Fe_(3)O_(4)@SiO_(2)@UiO-66-NH_(2)(MMOF)was prepared and used as a carrier to immobilize Lac(Lac@MMOF)for TC degradation.Benefiting from the multiple binding sites,adsorption,and protection effect of MMOF,Lac@MMOF displayed a wider pH application range(2–7)and better thermal(15–85℃),repeatability,and storage stability than free Lac.Furthermore,owing to the synergism of MOF adsorption and Lac biocatalysis,the removal rate of Lac@MMOF for TC could be up to 98%at pH=7 within 1 hr,which was 1.29 and 1.24 times that of free Lac and MMOF,respectively.More importantly,Lac@MMOF could easily be separated from aqueous solution under a magnetic field and maintained good removal performance(80%)after five cycles.The degradation products were identified by applying LC-MS/MS,and possible degradation mechanisms and pathways were proposed.Finally,the antibacterial activity of intermediate products was evaluated using Escherichia coli,which revealed that the toxicity of TC was reduced effectively by the degradation of Lac@MMOF.Overall,Lac@MMOF is a green alternative for residual antibiotic removal in water.展开更多
Heterogeneous interface engineering is key to tailoring intrinsic electromagnetic wave(EMW)attenuation.However,fully harnessing the functional benefits of these interfaces requires precise control of their architectur...Heterogeneous interface engineering is key to tailoring intrinsic electromagnetic wave(EMW)attenuation.However,fully harnessing the functional benefits of these interfaces requires precise control of their architecture—a major challenge in hierarchical heterostructure design.Herein,a stepwise confinement strategy is proposed to construct hierarchical heterogeneous interfaces in situ within graphene aerogels,incorporating zeolitic imidazolate framework-67(ZIF-67)nanoparticles and a polysilazane nanolayer embedding ZIF-67.Through synchronous thermal decomposition of magnetic metal and ceramics precursors,Co/CoO nanocrystals and an amorphous SiCN nanolayer are uniformly anchored onto the reduced graphene oxide(rGO)framework,creating hierarchically organized heterogeneous interfaces that comprise both nanoscale zero-dimensional(0D)–two-dimensional(2D)assemblies,such as ZIF-67-derived Co/CoO nanocrystals anchored on SiCN or rGO sheets,and extended 2D–2D contacts between the SiCN and rGO layers.These engineered heterointerfaces may induce an inhomogeneous spatial charge distribution,which in turn enhances interfacial polarization.Benefiting from synergistic magnetic–dielectric loss and improved impedance matching,the optimized magnetic graphene‒SiCN aerogel achieves a minimum reflection loss of-60.63 dB at a low frequency of 5.52 GHz and a broad effective absorption bandwidth of 7.89 GHz at a thickness of 2.4 mm.This work provides valuable insights into hierarchical heterostructure design and the fundamental electromagnetic response mechanisms governed by heterointerface engineering,paving the way for next-generation electromagnetic wave(EMW)-absorbing materials.展开更多
Recommendation systems(RSs)are crucial in personalizing user experiences in digital environments by suggesting relevant content or items.Collaborative filtering(CF)is a widely used personalization technique that lever...Recommendation systems(RSs)are crucial in personalizing user experiences in digital environments by suggesting relevant content or items.Collaborative filtering(CF)is a widely used personalization technique that leverages user-item interactions to generate recommendations.However,it struggles with challenges like the cold-start problem,scalability issues,and data sparsity.To address these limitations,we develop a Graph Convolutional Networks(GCNs)model that captures the complex network of interactions between users and items,identifying subtle patterns that traditional methods may overlook.We integrate this GCNs model into a federated learning(FL)framework,enabling themodel to learn fromdecentralized datasets.This not only significantly enhances user privacy—a significant improvement over conventionalmodels but also reassures users about the safety of their data.Additionally,by securely incorporating demographic information,our approach further personalizes recommendations and mitigates the coldstart issue without compromising user data.We validate our RSs model using the openMovieLens dataset and evaluate its performance across six key metrics:Precision,Recall,Area Under the Receiver Operating Characteristic Curve(ROC-AUC),F1 Score,Normalized Discounted Cumulative Gain(NDCG),and Mean Reciprocal Rank(MRR).The experimental results demonstrate significant enhancements in recommendation quality,underscoring that combining GCNs with CF in a federated setting provides a transformative solution for advanced recommendation systems.展开更多
As electromagnetic(EM)pollution intensifies,EM protection materials have garnered significant attention.However,the development of lightweight and efficient EM protection materials still faces numerous challenges.In t...As electromagnetic(EM)pollution intensifies,EM protection materials have garnered significant attention.However,the development of lightweight and efficient EM protection materials still faces numerous challenges.In this work,a bilayered metal-organic framework(MOF),specifically zeolitic imidazolate framework-8@zeolitic imidazolate framework-67(ZIF-8@ZIF-67),is initially prepared.Subsequently,through a combination of electrospinning and high-temperature carbonization processes,a heterodimensional structure featuring carbon-based dodecahedrons tandemly arranged on carbon nanofibers was obtained.The carbonization at various temperatures modulated the nanofibers'conductive network and graphitization of dodecahedrons,thereby regulating the dielectric response,which is crucial for tuning the EM properties of the material.Furthermore,dielectric-magnetic synergy also plays a certain role in optimizing microwave absorption performance.The Co-CHD@CNF800 with 60 wt%loading content demonstrates a minimum reflection loss(RL)of-53.6 dB at 1.83 mm,while 40 wt%loading content exhibits a maximum effective absorption bandwidth(EAB)of 6 GHz at 2.67 mm.Additionally,Co-CHD@CNF1000 with 80 wt%exhibits remarkable electromagnetic interference(EMI)shielding performance.Importantly,an EM energy conversion device has been constructed that can effectively recover and utilize harmful EM energy.This research presents an innovative approach to the development of lightweight and efficient EM protection materials and devices.展开更多
Wireless Sensor Networks(WSNs)are one of the best technologies of the 21st century and have seen tremendous growth over the past decade.Much work has been put into its development in various aspects such as architectu...Wireless Sensor Networks(WSNs)are one of the best technologies of the 21st century and have seen tremendous growth over the past decade.Much work has been put into its development in various aspects such as architectural attention,routing protocols,location exploration,time exploration,etc.This research aims to optimize routing protocols and address the challenges arising from conflicting objectives in WSN environments,such as balancing energy consumption,ensuring routing reliability,distributing network load,and selecting the shortest path.Many optimization techniques have shown success in achieving one or two objectives but struggle to achieve the right balance between multiple conflicting objectives.To address this gap,this paper proposes an innovative approach that integrates Particle Swarm Optimization(PSO)with a fuzzy multi-objective framework.The proposed method uses fuzzy logic to effectively control multiple competing objectives to represent its major development beyond existing methods that only deal with one or two objectives.The search efficiency is improved by particle swarm optimization(PSO)which overcomes the large computational requirements that serve as a major drawback of existing methods.The PSO algorithm is adapted for WSNs to optimize routing paths based on fuzzy multi-objective fitness.The fuzzy logic framework uses predefined membership functions and rule-based reasoning to adjust routing decisions.These adjustments influence PSO’s velocity updates,ensuring continuous adaptation under varying network conditions.The proposed multi-objective PSO-fuzzy model is evaluated using NS-3 simulation.The results show that the proposed model is capable of improving the network lifetime by 15.2%–22.4%,increasing the stabilization time by 18.7%–25.5%,and increasing the residual energy by 8.9%–16.2% compared to the state-of-the-art techniques.The proposed model also achieves a 15%–24% reduction in load variance,demonstrating balanced routing and extended network lifetime.Furthermore,analysis using p-values obtained from multiple performance measures(p-values<0.05)showed that the proposed approach outperforms with a high level of confidence.The proposed multi-objective PSO-fuzzy model provides a robust and scalable solution to improve the performance of WSNs.It allows stable performance in networks with 100 to 300 nodes,under varying node densities,and across different base station placements.Computational complexity analysis has shown that the method fits well into large-scale WSNs and that the addition of fuzzy logic controls the power usage to make the system practical for real-world use.展开更多
文摘Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully constructed by coordinatively assembling the semi-rigid multidentate ligand 5-(1-carboxyethoxy)isophthalic acid(H₃CIA)with the Nheterocyclic ligands 1,4-di(4H-1,2,4-triazol-4-yl)benzene(1,4-dtb)and 1,4-di(1H-imidazol-1-yl)benzene(1,4-dib),respectively,around Co^(2+)ions.Single-crystal X-ray diffraction analysis revealed that in both complexes HU23 and HU24,the CIA^(3-)anions adopt aκ^(7)-coordination mode,bridging six Co^(2+)ions via their five carboxylate oxygen atoms and one ether oxygen atom.This linkage forms tetranuclear[Co4(μ3-OH)2]^(6+)units.These Co-oxo cluster units were interconnected by CIA^(3-)anions to assemble into 2D kgd-type structures featuring a 3,6-connected topology.The 2D layers were further connected by 1,4-dtb and 1,4-dib,resulting in 3D pillar-layered frameworks for HU23 and HU24.Notably,despite the similar configurations of 1,4-dtb and 1,4-dib,differences in their coordination spatial orientations lead to topological divergence in the 3D frameworks of HU23 and HU24.Topological analysis indicates that the frameworks of HU23 and HU24 can be simplified into a 3,10-connected net(point symbol:(4^(10).6^(3).8^(2))(4^(3))_(2))and a 3,8-connected tfz-d net(point symbol:(4^(3))_(2)((4^(6).6^(18).8^(4)))),respectively.This structural differentiation confirms the precise regulatory role of ligands on the topology of metal-organic frameworks.Moreover,the ultraviolet-visible absorption spectra confirmed that HU23 and HU24 have strong absorption capabilities for ultraviolet and visible light.According to the Kubelka-Munk method,their bandwidths were 2.15 and 2.08 eV,respectively,which are consistent with those of typical semiconductor materials.Variable-temperature magnetic susceptibility measurements(2-300 K)revealed significant antiferromagnetic coupling in both complexes,with their effective magnetic moments decreasing markedly as the temperature lowered.CCDC:2457554,HU23;2457553,HU24.
基金supported by China Southern Power Grid Company Limited(066500KK52222006).
文摘The increasing intelligence of power systems is transforming distribution networks into Cyber-Physical Distribution Systems(CPDS).While enabling advanced functionalities,the tight interdependence between cyber and physical layers introduces significant security challenges and amplifies operational risks.To address these critical issues,this paper proposes a comprehensive risk assessment framework that explicitly incorporates the physical dependence of information systems.A Bayesian attack graph is employed to quantitatively evaluate the likelihood of successful cyber attacks.By analyzing the critical scenario of fault current path misjudgment,we define novel system-level and node-level risk coupling indices to preciselymeasure the cascading impacts across cyber and physical domains.Furthermore,an attack-responsive power recovery optimization model is established,integrating DistFlowbased physical constraints and sophisticated modeling of information-dependent interference.To enhance resilience against varying attack scenarios,a defense resource allocation model is constructed,where the complex Mixed-Integer Nonlinear Programming(MINLP)problem is efficiently linearized into a Mixed-Integer Linear Programming(MILP)formulation.Finally,to mitigate the impact of targeted attacks,the optimal deployment of terminal defense resources is determined using a Stackelberg game-theoretic approach,aiming to minimize overall system risk.The robustness and effectiveness of the proposed integrated framework are rigorously validated through extensive simulations under diverse attack intensities and defense resource constraints.
基金supported by the Natural Science Research Project of the Anhui Educational Committee,China(No.2022AH050827)the Open Research Fund Program of Anhui Province Key Laboratory of Specialty Polymers,Anhui University of Science and Technology,China(No.AHKLSP23-12)the Joint National-Local Engineering Research Center for Safe and Precise Coal Mining Fund,China(No.EC2022020)。
文摘The preparation of carbon-based electromagnetic wave(EMW)absorbers possessing thin matching thickness,wide absorption bandwidth,strong absorption intensity,and low filling ratio remains a huge challenge.Metal-organic frameworks(MOFs)are ideal self-sacrificing templates for the construction of carbon-based EMW absorbers.In this work,bimetallic FeMn-MOF-derived MnFe_(2)O_(4)/C/graphene composites were fabricated via a two-step route of solvothermal reaction and the following pyrolysis treatment.The results re-veal the evolution of the microscopic morphology of carbon skeletons from loofah-like to octahedral and then to polyhedron and pomegran-ate after the adjustment of the Fe^(3+)to Mn^(2+)molar ratio.Furthermore,at the Fe^(3+)to Mn^(2+)molar ratio of 2:1,the obtained MnFe_(2)O_(4)/C/graphene composite exhibited the highest EMW absorption capacity.Specifically,a minimum reflection loss of-72.7 dB and a max-imum effective absorption bandwidth of 5.1 GHz were achieved at a low filling ratio of 10wt%.In addition,the possible EMW absorp-tion mechanism of MnFe_(2)O_(4)/C/graphene composites was proposed.Therefore,the results of this work will contribute to the construction of broadband and efficient carbon-based EMW absorbers derived from MOFs.
基金sponsored by the National Natural Science Foundation of China (Nos. 22106038, 22204171 and 22076038)the Henan Provincial Science and Technology Research Project (No. 232102310112)+2 种基金the China Postdoctoral Science Foundation (No. 2022M713299)Natural Science Foundation of Henan Province, China (No. 202300410044)Henan key scientific research programs to Universities and Colleges (No. 22ZX003)。
文摘A thickness-controllable method for preparing metal-organic framework hollow nanofiowers on magnetic cores(Fe_(3)O_(4)@MOFs HFs)was demonstrated for the first time.The petal of magnetic core with hollow nanofiower structure served as medium for assembling Ui O-66-NH_(2)shell with different thickness.To further improve its performance,Zr^(4+)was immobilized on the surface of Fe_(3)O_(4)@Ui O-66-NH_(2).Compared with conventional Fe_(3)O_(4)@Ui O-66-NH_(2)-Zr^(4+)nanospheres,the Fe_(3)O_(4)@Ui O-66-NH2-Zr4+HFs showed increased enrichment performance for phosphopeptides.The Fe_(3)O_(4)@Ui O-66-NH2-Zr4+HFs served as an attractive restricted-access adsorption material exhibited good selectivity(m_(β-casein):m_(BSA)=1:1000),high sensitivity(1.0 fmol)and excellent size-exclusion effect(m)((β-casein digests):m_(BSA)=1:200).Furthermore,the Fe_(3)O_(4)@Ui O-66-NH_(2)-Zr^(4+)HFs was successfully applied to the specific capture of ultratrace phosphopeptide from complex biological samples,revealing the great potential for the identification and analysis of trace phosphopeptides in clinical analysis.This work can be easily extended to the fabrication of diverse mag-MOF HFs with multifunctional and easy to post-modify properties,and open up a new avenue for the design and construction of new MOFs material.
基金financially supported by Joint Funds of the National Natural Science Foundation of China(Nos.U23A20673,U22A20244,and 52478261)Qingchuang Technology Project(No.2021KJ045)+1 种基金the China Postdoctoral Science Foundation(No.2024M750580)the Key Laboratory of Functional Inorganic Material Chemistry(Heilongjiang University),Ministry of Education
文摘Carbon-based sponge materials have attracted massive attention as electromagnetic wave(EMW)absorber candidates due to their lightweight and excellent electromagnetic(EM)attenuation capability.However,the high cost,complex fabrication process and limited EMW absorption bandwidth restrict their application.Herein,a hierarchical threedimensional(3D)cotton derived carbon fibers coated with core–shell structure Fe Ni nanoparticle@porous carbon(CCF/Fe Ni@PC)from MOF precursor were successfully constructed by coprecipitation and one-step pyrolysis methods.By regulating carbonization temperature,optimizing the electromagnetic parameters,outstanding electromagnetic absorption(EMA)performance was achieved.The CCF@Fe Ni/PC synthesized at 900℃demonstrates a-64.5 d B minimum reflection loss(RL_(min))at 15.39 GHz,and the effective absorption bandwidth(EAB)is 5.08 GHz when the thickness is only1.9 mm.Notably,the maximum EAB(EAB_(max))was extended8.18 GHz at 2.96 mm for Fe Ni-800.The excellent microwave absorption performance is attributed to the synergistic effect of enhanced dielectric loss and magnetic loss,good impedance matching as well as hierarchical multiple scattering and reflection of EMWs.The obtained CCF@Fe Ni/PC composites provide a novel and promising strategy for constructing lightweight low-cost efficient microwave absorption materials.
文摘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.
基金supported by the National Natural Science Foundation of China(52473206,U21A20330,52073118)the“111”Project(B18012l)+1 种基金the Shenzhen Science and Technology Plan Funding(JCYJ20230807112800001)the Open Research Funding of State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences(PPCL2024-016)。
文摘While single-ion conducting solid polymer electrolytes(SPE)offer inherent safety advantages for lithium metal batteries,their practical implementation is hindered by inadequate ionic transport and unstable electrode interfaces.We presented a breakthrough single-ion SPE system through molecular engineering of lithium-enriched porous aromatic frameworks(PAF-228-Li)integrated with poly(ethylene oxide),achieving exceptional ion conduction and interfacial stability.The precisely designed PAF-228-Li architecture established continuous 3D Li+transport pathways through its intrinsic porous channels and surface conduction sites,synergistically enhanced by PVDF-HFP nanofiber networks.This unique design enabled record-high ionic conductivities of 5.48×10^(-4)S cm^(-1)at 30℃and 3.4×10^(-4)S cm^(-1)at-20℃—among the best reported for PEO-based SPEs.The electrolyte spontaneously formed a selflimiting SEI rich in LiF/Li3N,effectively suppressing dendritic growth while enabling unprecedented cycling stability:Li||LiFePO4cells maintain 83.7%capacity over 700 cycles(30℃)and deliver 104.4 mA h g^(-1)after 1100 cycles at-20℃.Practical viability is further demonstrated in pouch cell configurations with stable operation at 30℃.This work pioneers a materials paradigm combining porous framework engineering with polymer electrolyte design,establishing new researching direction for low-temperature compatible,dendrite-resistant solid-state batteries.
基金supported by the National Natural Science Foundation of China(NSFC)(61821005).
文摘Metal–organic frameworks(MOFs)hold great potential for gas separation and storage,and graph neural networks have proven to be a powerful tool for exploring material structure–property relationships and discovering new materials.Unlike traditional molecular graphs,crystal graphs require consideration of periodic invariance and modes.In addition,MOF structures such as covalent bonds,functional groups,and global structures impact adsorption performance in different ways.However,redundant atomic interactions can disrupt training accuracy,potentially leading to overfitting.In this paper,we propose a multi-scale crystal graph for describing periodic crystal structures,modeling interatomic interactions at different scales while preserving periodicity invariance.We also propose a multi-head attention crystal graph network in multi-scale graphs(MHACGN-MS),which learns structural characteristics by focusing on interatomic interactions at different scales,thereby reducing interference from redundant interactions.Using MOF adsorption for gases as an example,we demonstrate that MHACGN-MS outperforms traditional graph neural networks in predicting multi-component gas adsorption.We also visualize attention scores to validate effective learning and demonstrate the model’s interpretability.
基金funded by the National Natural Science Foundation of China(grant number 62306186)the Technology Plan Joint Foundation of Liaoning Province(grant number 2023-MSLH-246)the Technology Plan Joint Foundation of Liaoning Province(grant number 2023-BSBA-238).
文摘Detecting surface defects on unused rails is crucial for evaluating rail quality and durability to ensure the safety of rail transportation.However,existing detection methods often struggle with challenges such as complex defect morphology,texture similarity,and fuzzy edges,leading to poor accuracy and missed detections.In order to resolve these problems,we propose MSCM-Net(Multi-Scale Cross-Modal Network),a multiscale cross-modal framework focused on detecting rail surface defects.MSCM-Net introduces an attention mechanism to dynamically weight the fusion of RGB and depth maps,effectively capturing and enhancing features at different scales for each modality.To further enrich feature representation and improve edge detection in blurred areas,we propose a multi-scale void fusion module that integrates multi-scale feature information.To improve cross-modal feature fusion,we develop a cross-enhanced fusion module that transfers fused features between layers to incorporate interlayer information.We also introduce a multimodal feature integration module,which merges modality-specific features from separate decoders into a shared decoder,enhancing detection by leveraging richer complementary information.Finally,we validate MSCM-Net on the NEU RSDDS-AUG RGB-depth dataset,comparing it against 12 leading methods,and the results show that MSCM-Net achieves superior performance on all metrics.
基金supported by the National Natural Science Foundation of China(No.U20A20133)the National Key Research and Development Program of China(No.2022YFF0606703).
文摘The arbitrary discharge of tetracycline(TC)residuals has seriously influenced the ecosystem and human health.Laccase(Lac)-based biodegradation technology is considered a more effective way to remove TC due to its high catalytic efficiency and less by-product.Nevertheless,free Lac suffers from poor stability,easy inactivation and difficult recovery,restricting its application.Immobilization of Lac is considered an efficient strategy for addressing these obstacles.In this study,a magnetic metal-organic framework of Fe_(3)O_(4)@SiO_(2)@UiO-66-NH_(2)(MMOF)was prepared and used as a carrier to immobilize Lac(Lac@MMOF)for TC degradation.Benefiting from the multiple binding sites,adsorption,and protection effect of MMOF,Lac@MMOF displayed a wider pH application range(2–7)and better thermal(15–85℃),repeatability,and storage stability than free Lac.Furthermore,owing to the synergism of MOF adsorption and Lac biocatalysis,the removal rate of Lac@MMOF for TC could be up to 98%at pH=7 within 1 hr,which was 1.29 and 1.24 times that of free Lac and MMOF,respectively.More importantly,Lac@MMOF could easily be separated from aqueous solution under a magnetic field and maintained good removal performance(80%)after five cycles.The degradation products were identified by applying LC-MS/MS,and possible degradation mechanisms and pathways were proposed.Finally,the antibacterial activity of intermediate products was evaluated using Escherichia coli,which revealed that the toxicity of TC was reduced effectively by the degradation of Lac@MMOF.Overall,Lac@MMOF is a green alternative for residual antibiotic removal in water.
基金National Natural Science Foundation of China(Nos.52573327,62071239,and 52102361)the 333 High-Level Talents Cultivation Project of Jiangsu Province(No.BRA2022094)+1 种基金the Young Elite Scientists Sponsorship Program by Jiangsu Association for Science and Technology(No.JSTJ2023XH047)China Postdoctoral Science Foundation(Nos.2022M721669 and 2025T180037).
文摘Heterogeneous interface engineering is key to tailoring intrinsic electromagnetic wave(EMW)attenuation.However,fully harnessing the functional benefits of these interfaces requires precise control of their architecture—a major challenge in hierarchical heterostructure design.Herein,a stepwise confinement strategy is proposed to construct hierarchical heterogeneous interfaces in situ within graphene aerogels,incorporating zeolitic imidazolate framework-67(ZIF-67)nanoparticles and a polysilazane nanolayer embedding ZIF-67.Through synchronous thermal decomposition of magnetic metal and ceramics precursors,Co/CoO nanocrystals and an amorphous SiCN nanolayer are uniformly anchored onto the reduced graphene oxide(rGO)framework,creating hierarchically organized heterogeneous interfaces that comprise both nanoscale zero-dimensional(0D)–two-dimensional(2D)assemblies,such as ZIF-67-derived Co/CoO nanocrystals anchored on SiCN or rGO sheets,and extended 2D–2D contacts between the SiCN and rGO layers.These engineered heterointerfaces may induce an inhomogeneous spatial charge distribution,which in turn enhances interfacial polarization.Benefiting from synergistic magnetic–dielectric loss and improved impedance matching,the optimized magnetic graphene‒SiCN aerogel achieves a minimum reflection loss of-60.63 dB at a low frequency of 5.52 GHz and a broad effective absorption bandwidth of 7.89 GHz at a thickness of 2.4 mm.This work provides valuable insights into hierarchical heterostructure design and the fundamental electromagnetic response mechanisms governed by heterointerface engineering,paving the way for next-generation electromagnetic wave(EMW)-absorbing materials.
基金funded by Soonchunhyang University,Grant Numbers 20241422BK21 FOUR(Fostering Outstanding Universities for Research,Grant Number 5199990914048).
文摘Recommendation systems(RSs)are crucial in personalizing user experiences in digital environments by suggesting relevant content or items.Collaborative filtering(CF)is a widely used personalization technique that leverages user-item interactions to generate recommendations.However,it struggles with challenges like the cold-start problem,scalability issues,and data sparsity.To address these limitations,we develop a Graph Convolutional Networks(GCNs)model that captures the complex network of interactions between users and items,identifying subtle patterns that traditional methods may overlook.We integrate this GCNs model into a federated learning(FL)framework,enabling themodel to learn fromdecentralized datasets.This not only significantly enhances user privacy—a significant improvement over conventionalmodels but also reassures users about the safety of their data.Additionally,by securely incorporating demographic information,our approach further personalizes recommendations and mitigates the coldstart issue without compromising user data.We validate our RSs model using the openMovieLens dataset and evaluate its performance across six key metrics:Precision,Recall,Area Under the Receiver Operating Characteristic Curve(ROC-AUC),F1 Score,Normalized Discounted Cumulative Gain(NDCG),and Mean Reciprocal Rank(MRR).The experimental results demonstrate significant enhancements in recommendation quality,underscoring that combining GCNs with CF in a federated setting provides a transformative solution for advanced recommendation systems.
基金supported by the National Natural Science Foundation of China(Nos.52373280,52177014,51977009,and 52273257).
文摘As electromagnetic(EM)pollution intensifies,EM protection materials have garnered significant attention.However,the development of lightweight and efficient EM protection materials still faces numerous challenges.In this work,a bilayered metal-organic framework(MOF),specifically zeolitic imidazolate framework-8@zeolitic imidazolate framework-67(ZIF-8@ZIF-67),is initially prepared.Subsequently,through a combination of electrospinning and high-temperature carbonization processes,a heterodimensional structure featuring carbon-based dodecahedrons tandemly arranged on carbon nanofibers was obtained.The carbonization at various temperatures modulated the nanofibers'conductive network and graphitization of dodecahedrons,thereby regulating the dielectric response,which is crucial for tuning the EM properties of the material.Furthermore,dielectric-magnetic synergy also plays a certain role in optimizing microwave absorption performance.The Co-CHD@CNF800 with 60 wt%loading content demonstrates a minimum reflection loss(RL)of-53.6 dB at 1.83 mm,while 40 wt%loading content exhibits a maximum effective absorption bandwidth(EAB)of 6 GHz at 2.67 mm.Additionally,Co-CHD@CNF1000 with 80 wt%exhibits remarkable electromagnetic interference(EMI)shielding performance.Importantly,an EM energy conversion device has been constructed that can effectively recover and utilize harmful EM energy.This research presents an innovative approach to the development of lightweight and efficient EM protection materials and devices.
基金funded by Deanship of Graduate studies and Scientific Research at Jouf University under grant No.(DGSSR-2023-2-02038).
文摘Wireless Sensor Networks(WSNs)are one of the best technologies of the 21st century and have seen tremendous growth over the past decade.Much work has been put into its development in various aspects such as architectural attention,routing protocols,location exploration,time exploration,etc.This research aims to optimize routing protocols and address the challenges arising from conflicting objectives in WSN environments,such as balancing energy consumption,ensuring routing reliability,distributing network load,and selecting the shortest path.Many optimization techniques have shown success in achieving one or two objectives but struggle to achieve the right balance between multiple conflicting objectives.To address this gap,this paper proposes an innovative approach that integrates Particle Swarm Optimization(PSO)with a fuzzy multi-objective framework.The proposed method uses fuzzy logic to effectively control multiple competing objectives to represent its major development beyond existing methods that only deal with one or two objectives.The search efficiency is improved by particle swarm optimization(PSO)which overcomes the large computational requirements that serve as a major drawback of existing methods.The PSO algorithm is adapted for WSNs to optimize routing paths based on fuzzy multi-objective fitness.The fuzzy logic framework uses predefined membership functions and rule-based reasoning to adjust routing decisions.These adjustments influence PSO’s velocity updates,ensuring continuous adaptation under varying network conditions.The proposed multi-objective PSO-fuzzy model is evaluated using NS-3 simulation.The results show that the proposed model is capable of improving the network lifetime by 15.2%–22.4%,increasing the stabilization time by 18.7%–25.5%,and increasing the residual energy by 8.9%–16.2% compared to the state-of-the-art techniques.The proposed model also achieves a 15%–24% reduction in load variance,demonstrating balanced routing and extended network lifetime.Furthermore,analysis using p-values obtained from multiple performance measures(p-values<0.05)showed that the proposed approach outperforms with a high level of confidence.The proposed multi-objective PSO-fuzzy model provides a robust and scalable solution to improve the performance of WSNs.It allows stable performance in networks with 100 to 300 nodes,under varying node densities,and across different base station placements.Computational complexity analysis has shown that the method fits well into large-scale WSNs and that the addition of fuzzy logic controls the power usage to make the system practical for real-world use.
