In this paper, the determinacy of regular lexical selectional restrictions is examined from both the internal structures of the single selectional restrictions (i.e.semantic selectional restrictions) and relationship ...In this paper, the determinacy of regular lexical selectional restrictions is examined from both the internal structures of the single selectional restrictions (i.e.semantic selectional restrictions) and relationship between the structures of several selectional restrictions. Hence, our analysis and description are shifted from casual and indeterminate strings and markers on case basis to determined rules and circumspect dynamic systems, from lexical precepts to knowledge precepts, from the state of memory to rational deduction and rhetorical devices. Further studies indicate that selectional restrictions are intertwined structures, a feature that makes it possible to be one of the bases for lexical selectional restrictions to come into existence. Its related theories are the grarantee for scientific observations of selectional restriction structures.展开更多
In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asy...In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asymptotic stability of the trivial solution and the positive periodic solution.Finally,numerical simulations are presented to validate our results.Our results show that age-selective harvesting is more conducive to sustainable population survival than non-age-selective harvesting.展开更多
Soft magnetic alloys are extensively used in various power electronic devices due to their advantageous properties,including high saturation magnetic induction,low coercivity,and high permeability.In certain applicati...Soft magnetic alloys are extensively used in various power electronic devices due to their advantageous properties,including high saturation magnetic induction,low coercivity,and high permeability.In certain applications,complex-shaped components are increasingly required for performance enhancement.Additive manufacturing technique,particularly selective laser melting(SLM),has emerged as an effective method for fabricating such complex-shaped soft magnetic components.SLM,a laserbased additive manufacturing technique,employs high-power-density lasers to melt and fuse metal powders within a powder bed selectively.This approach enables rapid prototyping,precise geometrical control,and the integration of multi-material designs.This review highlights recent advancements in the application of SLM technique for the production of soft magnetic alloys,focusing on Fe-Si,Fe-Ni,Fe-Co,and amorphous alloy systems.Moreover,it explores the implementation of SLM in manufacturing processes and evaluates both the opportunities and challenges associated with SLM-based production of soft magnetic alloys.展开更多
To explore the formation mechanism of anisotropy in Ti-6Al-4V alloy fabricated by selective laser melting(SLM),the compressive mechanical properties,microhardness,microstructure,and crystallographic orientation of the...To explore the formation mechanism of anisotropy in Ti-6Al-4V alloy fabricated by selective laser melting(SLM),the compressive mechanical properties,microhardness,microstructure,and crystallographic orientation of the alloy across different planes were investigated.The anisotropy of SLM-fabricated Ti-6Al-4V alloys was analyzed,and the electron backscatter diffraction technique was used to investigate the influence of different grain types and orientations on the stress-strain distribution at various scales.Results reveal that in room-temperature compression tests at a strain rate of 10^(-3) s^(-1),both the compressive yield strength and microhardness vary along the deposition direction,indicating a certain degree of mechanical property anisotropy.The alloy exhibits a columnar microstructure;along the deposition direction,the grains appear equiaxed,and they have internal hexagonal close-packed(hcp)α/α'martensitic structure.α'phase has a preferential orientation approximately along the<0001>direction.Anisotropy arises from the high aspect ratio of columnar grains,along with the weak texture of the microstructure and low symmetry of the hcp crystal structure.展开更多
A multi-physics approach was used to quantify the effect of process parameters (laser power, scanning speed, hatch spacing, and scanning strategy) on the thermal history and corresponding microstructure evolution of T...A multi-physics approach was used to quantify the effect of process parameters (laser power, scanning speed, hatch spacing, and scanning strategy) on the thermal history and corresponding microstructure evolution of Ti-25Nb (at%) alloy during the dual-track selective laser melting (SLM) process. Simulation results reveal that during the dual-track SLM process, increasing laser power results in greater thermal accumulation, leading to a molten pool of larger volume and coarser grains. Reducing scanning speed enhances remelting and promotes cellular growth at the top of molten pool, whereas faster scanning speed leads to rougher melt tracks and finer grains. Notably, hatch spacing significantly influences the molten pool dimensions and microstructures, and smaller hatch spacing promotes remelting. Furthermore, the orientations of grains in the second track during zigzag scanning differ markedly from those in the first track. More importantly, compared with those after the first track, both the temperature gradient and cooling rate at the boundaries of remelting molten pool are reduced after the second track scanning, resulting in slower interface velocity and significant change in solidification microstructure. This research provides a theoretical foundation for controlling non-equilibrium microstructure and offering novel insights into the optimization of SLM process parameters of titanium alloys.展开更多
Herein,antibacterial silver‑doped fluorescent carbon dots(Ag‑CDs)were synthesized through a stepwise hydrothermal method,with polyethyleneimine(PEI),citric acid(CA),and silver nitrate(AgNO3)serving as precursors.The a...Herein,antibacterial silver‑doped fluorescent carbon dots(Ag‑CDs)were synthesized through a stepwise hydrothermal method,with polyethyleneimine(PEI),citric acid(CA),and silver nitrate(AgNO3)serving as precursors.The applicability and antimicrobial efficacy of these nanomaterials were systematically investigated for metal ion sensing.Experimental evidence demonstrated that the Ag‑CDs exhibited a pronounced fluorescence quenching response toward ferric ions(Fe^(3+)),enabling their quantitative determination via a linear concentration‑dependent relationship.These Ag‑CDs exhibited significant inhibitory effects on biofilm growth and disruption for both Escherichia coli and Staphylococcus aureus.Mechanism investigations indicate that Ag‑CDs induced the death of Escherichia coli and Pseudomonas aeruginosa by disrupting their bacterial morphology and structure,triggering the generation of intracellular reactive oxygen species(ROS),and impairing their antioxidant defense system.展开更多
Under the context of global energy transition and carbon neutrality,controlling nitrogen oxide(NO_(x))emissions from biomass combustion is of great significance,and the development of high-efficiency low-temperature c...Under the context of global energy transition and carbon neutrality,controlling nitrogen oxide(NO_(x))emissions from biomass combustion is of great significance,and the development of high-efficiency low-temperature catalysts has become a current research focus.In this study,Nb was used to dope and modify the Mn_(7)-Cu_(3)/BCN catalyst to construct the Mn_(7)-Cu_(3)-Nb_(x)/BCN system.The doping amount was optimized through selective catalytic reduction(SCR)activity tests.The reaction mechanism was explored by combining in situ DRIFTS and density functional theory(DFT)simulations.Experimental findings revealed that the catalyst doped with 0.05%Nb achieved the optimal performance,sustaining a NO conversion efficiency of≥94%within the temperature window of 150−275℃while demonstrating improved resistance to alkali metal K poisoning.Mechanistic analyses showed that at low temperatures,the catalyst facilitated the SCR reaction via both the Eley-Rideal(E-R)and Langmuir-Hinshelwood(L-H)pathways,with the synergistic interaction between multiple active sites driving the efficient conversion of NH3 and NO.DFT calculations further confirmed that both pathways had the characteristics of low reaction energy barriers and significant exothermicity,ensuring the high activity and feasibility of the low-temperature reaction.The findings provided foundational theoretical support for the design of Nb-doped Mn-Cu-supported catalysts and the exploration of the underlying working mechanisms.展开更多
Dear Editors,This letter,reflecting on my research career,is dedi-cated to Professor Qingshi Zhu for his 80th Birthday.Part of this letter is based on my comment“A 20-year journey on the invention of vibrational phot...Dear Editors,This letter,reflecting on my research career,is dedi-cated to Professor Qingshi Zhu for his 80th Birthday.Part of this letter is based on my comment“A 20-year journey on the invention of vibrational photothermal microscopy”published in the May 2025 Nature Meth-ods Focus Issue on Bond-Selective Imaging[1].展开更多
The Financial Technology(FinTech)sector has witnessed rapid growth,resulting in increasingly complex and high-volume digital transactions.Although this expansion improves efficiency and accessibility,it also introduce...The Financial Technology(FinTech)sector has witnessed rapid growth,resulting in increasingly complex and high-volume digital transactions.Although this expansion improves efficiency and accessibility,it also introduces significant vulnerabilities,including fraud,money laundering,and market manipulation.Traditional anomaly detection techniques often fail to capture the relational and dynamic characteristics of financial data.Graph Neural Networks(GNNs),capable of modeling intricate interdependencies among entities,have emerged as a powerful framework for detecting subtle and sophisticated anomalies.However,the high-dimensionality and inherent noise of FinTech datasets demand robust feature selection strategies to improve model scalability,performance,and interpretability.This paper presents a comprehensive survey of GNN-based approaches for anomaly detection in FinTech,with an emphasis on the synergistic role of feature selection.We examine the theoretical foundations of GNNs,review state-of-the-art feature selection techniques,analyze their integration with GNNs,and categorize prevalent anomaly types in FinTech applications.In addition,we discuss practical implementation challenges,highlight representative case studies,and propose future research directions to advance the field of graph-based anomaly detection in financial systems.展开更多
Directly burning methane for energy production wastes chemical potential and exacerbates CO_(2) emissions,while catalytic conversion into high-value fuel/chemicals provides economic and environmental sustainability.Ph...Directly burning methane for energy production wastes chemical potential and exacerbates CO_(2) emissions,while catalytic conversion into high-value fuel/chemicals provides economic and environmental sustainability.Photocatalytic CH_(4) conversion has emerged as a transformative technology,enabling selective oxidation under ambient conditions to directly synthesize value-added organic compounds.This addresses the dual challenges of climate mitigation and sustainable energy conversion.This review systematically examines the development of photocata lytic CH_(4) conversion,with three key dimensions.Firstly,we elucidate fundamental reaction mechanisms governing CH_(4) activation,emphasizing critical steps such as C-H bond scission via charge transfer,intermediate stabilization,and product desorption kinetics.Subsequently,we classify emerging photocata lytic pathways(partial oxidation,coupling,and reforming)and analyze material innovations.Finally,the challenges of the current photocata lytic CH_(4)conversion system and catalyst development were discussed,and perspectives were presented.The overarching objective of this work is to provide a comprehensive roadmap for the development of solardriven CH_(4) conversion systems that are aligned with global carbon neutrality goals.展开更多
By means the in situ halogenation of the vinyl C-H bond in o-hydroxyphenyl enaminones,the step efficient synthesis of 3-diphenylphosphinyl chromones has been realized through the challenging construction of C-P(Ⅲ) bo...By means the in situ halogenation of the vinyl C-H bond in o-hydroxyphenyl enaminones,the step efficient synthesis of 3-diphenylphosphinyl chromones has been realized through the challenging construction of C-P(Ⅲ) bond by using diphenyl phosphine as reaction partner.In addition,the tunable synthesis of 2-phosphoryl chromanones has been achieved via hydrophosphorylation by simply modifying reaction conditions without using metal reagent.展开更多
With the increasing complexity of vehicular networks and the proliferation of connected vehicles,Federated Learning(FL)has emerged as a critical framework for decentralized model training while preserving data privacy...With the increasing complexity of vehicular networks and the proliferation of connected vehicles,Federated Learning(FL)has emerged as a critical framework for decentralized model training while preserving data privacy.However,efficient client selection and adaptive weight allocation in heterogeneous and non-IID environments remain challenging.To address these issues,we propose Federated Learning with Client Selection and Adaptive Weighting(FedCW),a novel algorithm that leverages adaptive client selection and dynamic weight allocation for optimizing model convergence in real-time vehicular networks.FedCW selects clients based on their Euclidean distance from the global model and dynamically adjusts aggregation weights to optimize both data diversity and model convergence.Experimental results show that FedCW significantly outperforms existing FL algorithms such as FedAvg,FedProx,and SCAFFOLD,particularly in non-IID settings,achieving faster convergence,higher accuracy,and reduced communication overhead.These findings demonstrate that FedCW provides an effective solution for enhancing the performance of FL in heterogeneous,edge-based computing environments.展开更多
Nanoporous polymers are extensively coated on various substrates to deliver optical,permselective,or other functions.However,it remains desired to fast produce uniform nanoporous polymer coatings on substrates with co...Nanoporous polymers are extensively coated on various substrates to deliver optical,permselective,or other functions.However,it remains desired to fast produce uniform nanoporous polymer coatings on substrates with complex surfaces.Herein,by manipulating the interactions between block copolymers and selective solvents,we prepare repairable nanoporous polymers on arbitrary substrates.This is realized by an extremely simple sequential coating process:sequential coating of block copolymers and their swelling agents on substrate surfaces.The swelling agents are comprised of two solvents that swell the constituent blocks of the copolymers to different degrees,rapidly producing polymer coatings with uniform,interconnected,sub-50 nm pores.This sequential coating process is able to conformally build nanoporous polymers on nonplanar substrates with large lateral sizes and complex surface features,and also to in situ repair defects arising during usages.We further demonstrate that the nanoporous coatings show excellent antireflective and membrane separation performances.This sequential coating process is dictated by polymer–solvent interactions,and is expected to find applications in diverse fields for its simplicity,adaptability,and the capability to produce well-defined nanoporosities.展开更多
Selective depression of pyrite remains a major bottleneck in copper flotation,particularly when high-pyrite ores are processed and saline water is used.In such environments,conventional approaches using lime and inert...Selective depression of pyrite remains a major bottleneck in copper flotation,particularly when high-pyrite ores are processed and saline water is used.In such environments,conventional approaches using lime and inert grinding media often fail to discriminate ef-fectively between pyrite and valuable copper minerals due to strong copper activation on pyrite surfaces.This study introduced a novel approach using inorganic radicals generated from peroxymonosulfate(PMS)to selectively oxidize and depress pyrite.Flotation tests with synthetic high-pyrite ore blends showed that PMS significantly reduced pyrite recovery while maintaining or improving chalcopyrite flot-ation.Ethylenediaminetetraacetic acid(EDTA)extraction confirmed selective oxidation of pyrite,and electron paramagnetic resonance(EPR)spectroscopy identified hydroxyl(·OH)and sulfate(SO_(4)^(·-))radicals as the dominant reactive species.Iron ions from grinding me-dia and mineral surfaces were identified as key activators of PMS.A major insight was pyrite’s dual role,acting both as a radical scav-enger and an activator,which made it highly reactive and susceptible to radical-induced oxidation.This process converted surface copper-sulfur species into copper hydroxides,effectively suppressing pyrite flotation.While previous studies have applied EPR to detect radicals in simplified activator/precursor systems,this study provides the first direct mechanistic evidence of radical-driven selectivity in flotation by detecting inorganic radicals in a complex flotation slurry,thereby demonstrating their persistence under industrially relevant conditions and establishing a foundation for more effective and targeted flotation strategies.展开更多
Coordinate transformation models often fail to account for nonlinear and spatially dependent distortions,leading to significant residual errors in geospatial applications.Here,we propose a residual-based neural correc...Coordinate transformation models often fail to account for nonlinear and spatially dependent distortions,leading to significant residual errors in geospatial applications.Here,we propose a residual-based neural correction(RBNC)strategy,in which a neural network learns to model only the systematic distortions left by an initial geometric transformation.By focusing solely on residual patterns,RBNC reduces model complexity and improves performance,particularly in scenarios with sparse or structured control point configurations.We evaluate the method using both simulated datasets(with varying distortion intensities and sampling strategies)and real-world image georeferencing tasks.Compared with direct neural network coordinate converters and classical transformation models,RBNC delivers more accurate and stable results under challenging conditions,while maintaining comparable performance in ideal cases.These findings demonstrate the effectiveness of residual modelling as a light-weight and robust alternative for improving coordinate transformation accuracy.展开更多
The effective and environmentally friendly management of oily wastewater,alongside the beneficial conversion of waste biomass,holds paramount importance for environmental conservation,public health,and sustainable soc...The effective and environmentally friendly management of oily wastewater,alongside the beneficial conversion of waste biomass,holds paramount importance for environmental conservation,public health,and sustainable societal progress.In this research,an innovative biomass core-shell bioreactor(CGC@SiO_(2) aerogel) with selective adsorption and degradation properties was developed.The reactor's core is composed of coffee cellulose aerogel,offering a porous framework conducive to microbial colonization while safeguarding microorganisms from adverse external factors.The shell integrates hydrophobic silica enriched with polydimethylsiloxane,which alters the material's hydrophilic properties,enabling it to remain afloat on water for up to 100 days.This superhydrophobic layer maintained a contact angle of 150° even after ten consecutive rubbings.Experimental results indicate that the material performs exceptionally well in oil-water separation,as demonstrated by its success in 9 consecutive oil-water separations.It achieved 99 % selective adsorption,91 % removal,and 46.2 % degradation of a 3 wt.% diesel solution under conditions of 37℃,120 r/min,and pH=7.Additionally,tests assessing environmental tolerance revealed the material's robust adaptability and stability across varying pH levels and temperatures.Compared to traditional hydrophobic and lipophilic materials or free-floating microorganisms,CGC@SiO2 aerogel not only efficiently captures oil pollutants but also degrades them into non-hazardous substances.Combining biodegradation with selective adsorption has shown to be an effective approach for treating oily wastewater,offering significant practical application potential.The low-carbon production of CGC@SiO2aerogel aligns with circular economy principles,underscoring its role in sustainable development.展开更多
The intractable trade-off between proton conductivity and vanadium ion selectivity,known as the‘transmission paradox’is a critical bottleneck hindering the commercialization of vanadium flow batteries(VFBs).Inspired...The intractable trade-off between proton conductivity and vanadium ion selectivity,known as the‘transmission paradox’is a critical bottleneck hindering the commercialization of vanadium flow batteries(VFBs).Inspired by the multi-stage,synergistic filtration mechanism of the mammalian glomerular filtration barrier,a novel,biomimetic hierarchical composite membrane has been fabricated via a precise layer-by-layer strategy on a polyethylene(PE)substrate.This membrane integrates a polydopamine(PDA)adhesion layer,a sulfonated Zr-MOF ion-sieving layer,and a synergistic polybenzimidazole(PBI)matrix.Spectroscopic analysis confirmed the formation of a critical bifunctional acid-base interface(-SO_(3)^(−)…H^(+)N-)between the MOF and PBI,which densifies the structure and optimizes ion pathways.The resulting composite membrane exhibits excellent mechanical robustness,superior chemical stability,and exceptional dimensional stability.Most significantly,this architecture successfully decouples the performance trade-off,demonstrating both high proton conductivity(11.11 mS·cm^(-1))and remarkably suppressed vanadium ion permeability(2.4×10^(−8) cm^(2)·min^(-1)).This combination yields an outstanding ion selectivity of 46.29×10^(4) S·min·cm^(-3).When tested in a VFB single cell,the membrane enabled a high energy efficiency of 81.6%at 200 mA·cm^(-2),an ultra-long self-discharge time of 2700 min,and excellent long-term cycling stability.This biomimetic design strategy effectively resolves the core‘transmission paradox’offering a promising pathway for next-generation high-performance flow batteries.展开更多
Recovery of palladium from spent catalysts is of great practical significance for the construction of ecological civilization and resource recycling.However,for environmentally friendly adsorption methods,designing sp...Recovery of palladium from spent catalysts is of great practical significance for the construction of ecological civilization and resource recycling.However,for environmentally friendly adsorption methods,designing specialized capture vacancies with high capacity and precise selectivity for Pd(Ⅱ) ions remains a challenge.Herein,a salicylic acid-modified nanofiber(SANF),exhibiting specific spatial configuration and constructing a capture vacancy by "O-O" of hard bases,was designed and employed for recovering and separating palladium.The adsorption results indicated that the SANF exhibited a fast capture rate(reaching adsorption equilibrium within60 min) and a large capture capacity(about 170 mg/g) for Pd(Ⅱ) ions,and the capture process was exothermic and spontaneous.Additionally,the Lewis basicity of the capture vacancy after tuning better matches the Lewis acidity of Pd(Ⅱ) ions,which achieves a high-selectivity separation of Pd(Ⅱ) ions(selectivity coefficient for K(Ⅰ),Na(Ⅰ) Ca(Ⅱ),Mg(Ⅱ) and Al(Ⅲ) ions are 1505.2,10,536.7,1128.9,2634.2 and 2873.6,respectively).Practical applications showed that SANF was enabled to recover Pd(Ⅱ) ions from spent catalyst leachate and achieved four time adsorption-desorption cycles,possessing some industrial promise.Furthermore,the matching mechanism between the Lewis basicity of the capture vacancy and the Lewis acidity of the Pd(Ⅱ) ions was revealed through series characterization and theoretical calculations.Finally,it is proposed a Lewis basicity tuning strategy founded on a specific spatial structure,provides a new insight for the design and construction of a capture vacancy for Pd(Ⅱ) ions in the future.展开更多
This paper aims to develop a unified Bayesian approach for clustered data analysis when observations are subject to missingness at random.The authors consider a general framework in which the parameters of interest ar...This paper aims to develop a unified Bayesian approach for clustered data analysis when observations are subject to missingness at random.The authors consider a general framework in which the parameters of interest are defined through estimating equations,and the probability of missingness follows a general parametric form.The generalized method of moments framework is employed to derive an optimal combination of inverse-probability-weighted estimating equations for the parameters of interest and score equations for propensity score.Using this framework,the authors develop a quasi-Bayesian analysis for clustered samples with missing values.A unified model selection approach is also proposed to compare models characterized by different moment conditions.The authors systematically evaluate the large-sample properties of the proposed quasi-posterior density with both fixed and shrinking priors and establish the selection consistency of the proposed model selection criterion.The proposed results are valid under very mild conditions and offer significant advantages for parameters defined through non-smooth estimating functions.Extensive numerical studies demonstrate that the proposed method performs exceptionally well in finite samples.展开更多
文摘In this paper, the determinacy of regular lexical selectional restrictions is examined from both the internal structures of the single selectional restrictions (i.e.semantic selectional restrictions) and relationship between the structures of several selectional restrictions. Hence, our analysis and description are shifted from casual and indeterminate strings and markers on case basis to determined rules and circumspect dynamic systems, from lexical precepts to knowledge precepts, from the state of memory to rational deduction and rhetorical devices. Further studies indicate that selectional restrictions are intertwined structures, a feature that makes it possible to be one of the bases for lexical selectional restrictions to come into existence. Its related theories are the grarantee for scientific observations of selectional restriction structures.
基金Supported by the National Natural Science Foundation of China(12261018)Universities Key Laboratory of Mathematical Modeling and Data Mining in Guizhou Province(2023013)。
文摘In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asymptotic stability of the trivial solution and the positive periodic solution.Finally,numerical simulations are presented to validate our results.Our results show that age-selective harvesting is more conducive to sustainable population survival than non-age-selective harvesting.
基金National Natural Science Foundation of China(52171191,52371198)Project of Constructing National Independent Innovation Demonstration Zones(XM2024XTGXQ05)。
文摘Soft magnetic alloys are extensively used in various power electronic devices due to their advantageous properties,including high saturation magnetic induction,low coercivity,and high permeability.In certain applications,complex-shaped components are increasingly required for performance enhancement.Additive manufacturing technique,particularly selective laser melting(SLM),has emerged as an effective method for fabricating such complex-shaped soft magnetic components.SLM,a laserbased additive manufacturing technique,employs high-power-density lasers to melt and fuse metal powders within a powder bed selectively.This approach enables rapid prototyping,precise geometrical control,and the integration of multi-material designs.This review highlights recent advancements in the application of SLM technique for the production of soft magnetic alloys,focusing on Fe-Si,Fe-Ni,Fe-Co,and amorphous alloy systems.Moreover,it explores the implementation of SLM in manufacturing processes and evaluates both the opportunities and challenges associated with SLM-based production of soft magnetic alloys.
基金National Natural Science Foundation of China(51504138,51674118,52271177)Hunan Provincial Natural Science Foundation of China(2023JJ50181)Supported by State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology(P2024-022)。
文摘To explore the formation mechanism of anisotropy in Ti-6Al-4V alloy fabricated by selective laser melting(SLM),the compressive mechanical properties,microhardness,microstructure,and crystallographic orientation of the alloy across different planes were investigated.The anisotropy of SLM-fabricated Ti-6Al-4V alloys was analyzed,and the electron backscatter diffraction technique was used to investigate the influence of different grain types and orientations on the stress-strain distribution at various scales.Results reveal that in room-temperature compression tests at a strain rate of 10^(-3) s^(-1),both the compressive yield strength and microhardness vary along the deposition direction,indicating a certain degree of mechanical property anisotropy.The alloy exhibits a columnar microstructure;along the deposition direction,the grains appear equiaxed,and they have internal hexagonal close-packed(hcp)α/α'martensitic structure.α'phase has a preferential orientation approximately along the<0001>direction.Anisotropy arises from the high aspect ratio of columnar grains,along with the weak texture of the microstructure and low symmetry of the hcp crystal structure.
基金Guangdong Basic and Applied Basic Research Foundation (2024A1515011873)Shenzhen Basic Research Project (JCYJ20241202123504007)Shenzhen Science and Technology Innovation Commission (KJZD20240903101400001, KJZD20240903102006009)。
文摘A multi-physics approach was used to quantify the effect of process parameters (laser power, scanning speed, hatch spacing, and scanning strategy) on the thermal history and corresponding microstructure evolution of Ti-25Nb (at%) alloy during the dual-track selective laser melting (SLM) process. Simulation results reveal that during the dual-track SLM process, increasing laser power results in greater thermal accumulation, leading to a molten pool of larger volume and coarser grains. Reducing scanning speed enhances remelting and promotes cellular growth at the top of molten pool, whereas faster scanning speed leads to rougher melt tracks and finer grains. Notably, hatch spacing significantly influences the molten pool dimensions and microstructures, and smaller hatch spacing promotes remelting. Furthermore, the orientations of grains in the second track during zigzag scanning differ markedly from those in the first track. More importantly, compared with those after the first track, both the temperature gradient and cooling rate at the boundaries of remelting molten pool are reduced after the second track scanning, resulting in slower interface velocity and significant change in solidification microstructure. This research provides a theoretical foundation for controlling non-equilibrium microstructure and offering novel insights into the optimization of SLM process parameters of titanium alloys.
文摘Herein,antibacterial silver‑doped fluorescent carbon dots(Ag‑CDs)were synthesized through a stepwise hydrothermal method,with polyethyleneimine(PEI),citric acid(CA),and silver nitrate(AgNO3)serving as precursors.The applicability and antimicrobial efficacy of these nanomaterials were systematically investigated for metal ion sensing.Experimental evidence demonstrated that the Ag‑CDs exhibited a pronounced fluorescence quenching response toward ferric ions(Fe^(3+)),enabling their quantitative determination via a linear concentration‑dependent relationship.These Ag‑CDs exhibited significant inhibitory effects on biofilm growth and disruption for both Escherichia coli and Staphylococcus aureus.Mechanism investigations indicate that Ag‑CDs induced the death of Escherichia coli and Pseudomonas aeruginosa by disrupting their bacterial morphology and structure,triggering the generation of intracellular reactive oxygen species(ROS),and impairing their antioxidant defense system.
基金Supported by National Key Research and Development Program of China(2020YFD1100302)。
文摘Under the context of global energy transition and carbon neutrality,controlling nitrogen oxide(NO_(x))emissions from biomass combustion is of great significance,and the development of high-efficiency low-temperature catalysts has become a current research focus.In this study,Nb was used to dope and modify the Mn_(7)-Cu_(3)/BCN catalyst to construct the Mn_(7)-Cu_(3)-Nb_(x)/BCN system.The doping amount was optimized through selective catalytic reduction(SCR)activity tests.The reaction mechanism was explored by combining in situ DRIFTS and density functional theory(DFT)simulations.Experimental findings revealed that the catalyst doped with 0.05%Nb achieved the optimal performance,sustaining a NO conversion efficiency of≥94%within the temperature window of 150−275℃while demonstrating improved resistance to alkali metal K poisoning.Mechanistic analyses showed that at low temperatures,the catalyst facilitated the SCR reaction via both the Eley-Rideal(E-R)and Langmuir-Hinshelwood(L-H)pathways,with the synergistic interaction between multiple active sites driving the efficient conversion of NH3 and NO.DFT calculations further confirmed that both pathways had the characteristics of low reaction energy barriers and significant exothermicity,ensuring the high activity and feasibility of the low-temperature reaction.The findings provided foundational theoretical support for the design of Nb-doped Mn-Cu-supported catalysts and the exploration of the underlying working mechanisms.
文摘Dear Editors,This letter,reflecting on my research career,is dedi-cated to Professor Qingshi Zhu for his 80th Birthday.Part of this letter is based on my comment“A 20-year journey on the invention of vibrational photothermal microscopy”published in the May 2025 Nature Meth-ods Focus Issue on Bond-Selective Imaging[1].
基金supported by Ho Chi Minh City Open University,Vietnam under grant number E2024.02.1CD and Suan Sunandha Rajabhat University,Thailand.
文摘The Financial Technology(FinTech)sector has witnessed rapid growth,resulting in increasingly complex and high-volume digital transactions.Although this expansion improves efficiency and accessibility,it also introduces significant vulnerabilities,including fraud,money laundering,and market manipulation.Traditional anomaly detection techniques often fail to capture the relational and dynamic characteristics of financial data.Graph Neural Networks(GNNs),capable of modeling intricate interdependencies among entities,have emerged as a powerful framework for detecting subtle and sophisticated anomalies.However,the high-dimensionality and inherent noise of FinTech datasets demand robust feature selection strategies to improve model scalability,performance,and interpretability.This paper presents a comprehensive survey of GNN-based approaches for anomaly detection in FinTech,with an emphasis on the synergistic role of feature selection.We examine the theoretical foundations of GNNs,review state-of-the-art feature selection techniques,analyze their integration with GNNs,and categorize prevalent anomaly types in FinTech applications.In addition,we discuss practical implementation challenges,highlight representative case studies,and propose future research directions to advance the field of graph-based anomaly detection in financial systems.
基金supported by the National Natural Science Foundation of China(No.52500142)the National Postdoctoral Program for Innovative Talents under Grant Number BX20250334the China Postdoctoral Science Foundation(Certificate Number:2025M771285)。
文摘Directly burning methane for energy production wastes chemical potential and exacerbates CO_(2) emissions,while catalytic conversion into high-value fuel/chemicals provides economic and environmental sustainability.Photocatalytic CH_(4) conversion has emerged as a transformative technology,enabling selective oxidation under ambient conditions to directly synthesize value-added organic compounds.This addresses the dual challenges of climate mitigation and sustainable energy conversion.This review systematically examines the development of photocata lytic CH_(4) conversion,with three key dimensions.Firstly,we elucidate fundamental reaction mechanisms governing CH_(4) activation,emphasizing critical steps such as C-H bond scission via charge transfer,intermediate stabilization,and product desorption kinetics.Subsequently,we classify emerging photocata lytic pathways(partial oxidation,coupling,and reforming)and analyze material innovations.Finally,the challenges of the current photocata lytic CH_(4)conversion system and catalyst development were discussed,and perspectives were presented.The overarching objective of this work is to provide a comprehensive roadmap for the development of solardriven CH_(4) conversion systems that are aligned with global carbon neutrality goals.
基金financially supported by the National Natural Science Foundation of China (No.22261026)。
文摘By means the in situ halogenation of the vinyl C-H bond in o-hydroxyphenyl enaminones,the step efficient synthesis of 3-diphenylphosphinyl chromones has been realized through the challenging construction of C-P(Ⅲ) bond by using diphenyl phosphine as reaction partner.In addition,the tunable synthesis of 2-phosphoryl chromanones has been achieved via hydrophosphorylation by simply modifying reaction conditions without using metal reagent.
文摘With the increasing complexity of vehicular networks and the proliferation of connected vehicles,Federated Learning(FL)has emerged as a critical framework for decentralized model training while preserving data privacy.However,efficient client selection and adaptive weight allocation in heterogeneous and non-IID environments remain challenging.To address these issues,we propose Federated Learning with Client Selection and Adaptive Weighting(FedCW),a novel algorithm that leverages adaptive client selection and dynamic weight allocation for optimizing model convergence in real-time vehicular networks.FedCW selects clients based on their Euclidean distance from the global model and dynamically adjusts aggregation weights to optimize both data diversity and model convergence.Experimental results show that FedCW significantly outperforms existing FL algorithms such as FedAvg,FedProx,and SCAFFOLD,particularly in non-IID settings,achieving faster convergence,higher accuracy,and reduced communication overhead.These findings demonstrate that FedCW provides an effective solution for enhancing the performance of FL in heterogeneous,edge-based computing environments.
基金support from National Science Foundation of China(22438005)the Natural Science Foundation of Jiangsu Province(BE2022056-3)is gratefully acknowledged.
文摘Nanoporous polymers are extensively coated on various substrates to deliver optical,permselective,or other functions.However,it remains desired to fast produce uniform nanoporous polymer coatings on substrates with complex surfaces.Herein,by manipulating the interactions between block copolymers and selective solvents,we prepare repairable nanoporous polymers on arbitrary substrates.This is realized by an extremely simple sequential coating process:sequential coating of block copolymers and their swelling agents on substrate surfaces.The swelling agents are comprised of two solvents that swell the constituent blocks of the copolymers to different degrees,rapidly producing polymer coatings with uniform,interconnected,sub-50 nm pores.This sequential coating process is able to conformally build nanoporous polymers on nonplanar substrates with large lateral sizes and complex surface features,and also to in situ repair defects arising during usages.We further demonstrate that the nanoporous coatings show excellent antireflective and membrane separation performances.This sequential coating process is dictated by polymer–solvent interactions,and is expected to find applications in diverse fields for its simplicity,adaptability,and the capability to produce well-defined nanoporosities.
基金support from the Australian Research Council(ARC)Linkage Project(No.LP230100166).
文摘Selective depression of pyrite remains a major bottleneck in copper flotation,particularly when high-pyrite ores are processed and saline water is used.In such environments,conventional approaches using lime and inert grinding media often fail to discriminate ef-fectively between pyrite and valuable copper minerals due to strong copper activation on pyrite surfaces.This study introduced a novel approach using inorganic radicals generated from peroxymonosulfate(PMS)to selectively oxidize and depress pyrite.Flotation tests with synthetic high-pyrite ore blends showed that PMS significantly reduced pyrite recovery while maintaining or improving chalcopyrite flot-ation.Ethylenediaminetetraacetic acid(EDTA)extraction confirmed selective oxidation of pyrite,and electron paramagnetic resonance(EPR)spectroscopy identified hydroxyl(·OH)and sulfate(SO_(4)^(·-))radicals as the dominant reactive species.Iron ions from grinding me-dia and mineral surfaces were identified as key activators of PMS.A major insight was pyrite’s dual role,acting both as a radical scav-enger and an activator,which made it highly reactive and susceptible to radical-induced oxidation.This process converted surface copper-sulfur species into copper hydroxides,effectively suppressing pyrite flotation.While previous studies have applied EPR to detect radicals in simplified activator/precursor systems,this study provides the first direct mechanistic evidence of radical-driven selectivity in flotation by detecting inorganic radicals in a complex flotation slurry,thereby demonstrating their persistence under industrially relevant conditions and establishing a foundation for more effective and targeted flotation strategies.
基金National Council for Scientific and Technological Development,Grant No.421278/2023-4,No.309248/2025-6。
文摘Coordinate transformation models often fail to account for nonlinear and spatially dependent distortions,leading to significant residual errors in geospatial applications.Here,we propose a residual-based neural correction(RBNC)strategy,in which a neural network learns to model only the systematic distortions left by an initial geometric transformation.By focusing solely on residual patterns,RBNC reduces model complexity and improves performance,particularly in scenarios with sparse or structured control point configurations.We evaluate the method using both simulated datasets(with varying distortion intensities and sampling strategies)and real-world image georeferencing tasks.Compared with direct neural network coordinate converters and classical transformation models,RBNC delivers more accurate and stable results under challenging conditions,while maintaining comparable performance in ideal cases.These findings demonstrate the effectiveness of residual modelling as a light-weight and robust alternative for improving coordinate transformation accuracy.
基金supported by the National Natural Science Foundation of China(Nos.22365026 and 21966028)the Science and Technology Project of Gansu(No.21YF5GA062)+3 种基金the Fundamental Research Funds for the Central Universities(Nos.31920220043,31920240094,and 31920230142)the Education Department of Gansu Province:Excellent Graduate student“Innovation Star”project(No.2023CXZX-202)Gansu Province Science Foundation for Youths(No.24JRRA160)the Funds for Special Projects of the Central Government in Guidance of Local Science and Technology Development(No.24ZY1QA026).
文摘The effective and environmentally friendly management of oily wastewater,alongside the beneficial conversion of waste biomass,holds paramount importance for environmental conservation,public health,and sustainable societal progress.In this research,an innovative biomass core-shell bioreactor(CGC@SiO_(2) aerogel) with selective adsorption and degradation properties was developed.The reactor's core is composed of coffee cellulose aerogel,offering a porous framework conducive to microbial colonization while safeguarding microorganisms from adverse external factors.The shell integrates hydrophobic silica enriched with polydimethylsiloxane,which alters the material's hydrophilic properties,enabling it to remain afloat on water for up to 100 days.This superhydrophobic layer maintained a contact angle of 150° even after ten consecutive rubbings.Experimental results indicate that the material performs exceptionally well in oil-water separation,as demonstrated by its success in 9 consecutive oil-water separations.It achieved 99 % selective adsorption,91 % removal,and 46.2 % degradation of a 3 wt.% diesel solution under conditions of 37℃,120 r/min,and pH=7.Additionally,tests assessing environmental tolerance revealed the material's robust adaptability and stability across varying pH levels and temperatures.Compared to traditional hydrophobic and lipophilic materials or free-floating microorganisms,CGC@SiO2 aerogel not only efficiently captures oil pollutants but also degrades them into non-hazardous substances.Combining biodegradation with selective adsorption has shown to be an effective approach for treating oily wastewater,offering significant practical application potential.The low-carbon production of CGC@SiO2aerogel aligns with circular economy principles,underscoring its role in sustainable development.
基金supported by the Natural Science Foundation of Liaoning Province(Grant Nos:2025-BSLH-247,2025-BSLH-246)Liaoning Provincial Department of Education Foundation(Grant Nos:LJ212410148012,LJ242510148002)+1 种基金Inner Mongolia’s Key R&D and Achievement Industrialization Program(Grant No:2025YFHH0017)China Postdoctoral Science Foundation(Grant Nos:2025MD774148,2025M770082).
文摘The intractable trade-off between proton conductivity and vanadium ion selectivity,known as the‘transmission paradox’is a critical bottleneck hindering the commercialization of vanadium flow batteries(VFBs).Inspired by the multi-stage,synergistic filtration mechanism of the mammalian glomerular filtration barrier,a novel,biomimetic hierarchical composite membrane has been fabricated via a precise layer-by-layer strategy on a polyethylene(PE)substrate.This membrane integrates a polydopamine(PDA)adhesion layer,a sulfonated Zr-MOF ion-sieving layer,and a synergistic polybenzimidazole(PBI)matrix.Spectroscopic analysis confirmed the formation of a critical bifunctional acid-base interface(-SO_(3)^(−)…H^(+)N-)between the MOF and PBI,which densifies the structure and optimizes ion pathways.The resulting composite membrane exhibits excellent mechanical robustness,superior chemical stability,and exceptional dimensional stability.Most significantly,this architecture successfully decouples the performance trade-off,demonstrating both high proton conductivity(11.11 mS·cm^(-1))and remarkably suppressed vanadium ion permeability(2.4×10^(−8) cm^(2)·min^(-1)).This combination yields an outstanding ion selectivity of 46.29×10^(4) S·min·cm^(-3).When tested in a VFB single cell,the membrane enabled a high energy efficiency of 81.6%at 200 mA·cm^(-2),an ultra-long self-discharge time of 2700 min,and excellent long-term cycling stability.This biomimetic design strategy effectively resolves the core‘transmission paradox’offering a promising pathway for next-generation high-performance flow batteries.
基金supported by Sichuan Science and Technology Program(No.2024YFHZ0103)Anhui Province Applied Peak Cultivation Discipline(No.XK-XJGF005)+1 种基金Anhui Province Quartz Sand Purification and Photovoltaic Glass Engineering Research Center(No.[2022]547-49)the Key research and development projects of Shandong Province(No.2023CXGC010903).
文摘Recovery of palladium from spent catalysts is of great practical significance for the construction of ecological civilization and resource recycling.However,for environmentally friendly adsorption methods,designing specialized capture vacancies with high capacity and precise selectivity for Pd(Ⅱ) ions remains a challenge.Herein,a salicylic acid-modified nanofiber(SANF),exhibiting specific spatial configuration and constructing a capture vacancy by "O-O" of hard bases,was designed and employed for recovering and separating palladium.The adsorption results indicated that the SANF exhibited a fast capture rate(reaching adsorption equilibrium within60 min) and a large capture capacity(about 170 mg/g) for Pd(Ⅱ) ions,and the capture process was exothermic and spontaneous.Additionally,the Lewis basicity of the capture vacancy after tuning better matches the Lewis acidity of Pd(Ⅱ) ions,which achieves a high-selectivity separation of Pd(Ⅱ) ions(selectivity coefficient for K(Ⅰ),Na(Ⅰ) Ca(Ⅱ),Mg(Ⅱ) and Al(Ⅲ) ions are 1505.2,10,536.7,1128.9,2634.2 and 2873.6,respectively).Practical applications showed that SANF was enabled to recover Pd(Ⅱ) ions from spent catalyst leachate and achieved four time adsorption-desorption cycles,possessing some industrial promise.Furthermore,the matching mechanism between the Lewis basicity of the capture vacancy and the Lewis acidity of the Pd(Ⅱ) ions was revealed through series characterization and theoretical calculations.Finally,it is proposed a Lewis basicity tuning strategy founded on a specific spatial structure,provides a new insight for the design and construction of a capture vacancy for Pd(Ⅱ) ions in the future.
基金supported by the National Key R&D Program of China under Grant No.2022YFA1003701the National Natural Science Foundation of China under Grant Nos.12331009 and 12071416the Yunnan Fundamental Research Projects under Grant No.202201AV070006。
文摘This paper aims to develop a unified Bayesian approach for clustered data analysis when observations are subject to missingness at random.The authors consider a general framework in which the parameters of interest are defined through estimating equations,and the probability of missingness follows a general parametric form.The generalized method of moments framework is employed to derive an optimal combination of inverse-probability-weighted estimating equations for the parameters of interest and score equations for propensity score.Using this framework,the authors develop a quasi-Bayesian analysis for clustered samples with missing values.A unified model selection approach is also proposed to compare models characterized by different moment conditions.The authors systematically evaluate the large-sample properties of the proposed quasi-posterior density with both fixed and shrinking priors and establish the selection consistency of the proposed model selection criterion.The proposed results are valid under very mild conditions and offer significant advantages for parameters defined through non-smooth estimating functions.Extensive numerical studies demonstrate that the proposed method performs exceptionally well in finite samples.
