To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content ...To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.展开更多
Alkali-free SiO_(2)-Al_(2)O_(3)-CaO-MgO with different SiO_(2)/Al_(2)O_(3)mass ratios was prepared by conventional melt quenching method.The glass network structure,thermodynamic properties and elastic modulus changes...Alkali-free SiO_(2)-Al_(2)O_(3)-CaO-MgO with different SiO_(2)/Al_(2)O_(3)mass ratios was prepared by conventional melt quenching method.The glass network structure,thermodynamic properties and elastic modulus changes with SiO_(2)and Al_(2)O_(3)ratios were investigated using various techniques.It is found that when SiO_(2)is replaced by Al_(2)O_(3),the Q^(4) to Q^(3) transition of silicon-oxygen network decreases while the aluminum-oxygen network increases,which result in the transformation of Si-O-Si bonds to Si-O-Al bonds and an increase in glass network connectivity even though the intermolecular bond strength decreases.The glass transition temperature(T_(g))increases continuously,while the thermal expansion coefficient increases and high-temperature viscosity first decreases and then increases.Meanwhile,the elastic modulus values increase from 93 to 102 GPa.This indicates that the elastic modulus is mainly affected by packing factor and dissociation energy,and elements with higher packing factors and dissociation energies supplant those with lower values,resulting in increased rigidity within the glass.展开更多
To investigate the pore structure of graphene oxide modified polymer cement mortar(GOPM)under salt-freeze-thaw(SFT)coupling effects and its impact on deterioration,this study modifies polymer cement mortar(EMCM)with g...To investigate the pore structure of graphene oxide modified polymer cement mortar(GOPM)under salt-freeze-thaw(SFT)coupling effects and its impact on deterioration,this study modifies polymer cement mortar(EMCM)with graphene oxide(GO).The micro-pore structure of GOPM is characterized using LF-NMR and SEM.Fractal theory is applied to calculate the fractal dimension of pore volume,and the deterioration patterns are analyzed based on the evolution characteristics of capillary pores.The experimental results indicate that,after 25 salt-freeze-thaw cycles(SFTc),SO2-4 ions penetrate the matrix,generating corrosion products that fill existing pores and enhance the compactness of the specimen.As the number of cycles increases,the ongoing formation and expansion of corrosion products within the matrix,combined with persistent freezing forces,and result in the degradation of the pore structure.Therefore,the mass loss rate(MLR)of the specimens shows a trend of first decreasing and then increasing,while the relative dynamic elastic modulus(RDEM)initially increases and then decreases.Compared to the PC group specimens,the G3PM group specimens show a 28.71% reduction in MLR and a 31.42% increase in RDEM after 150 SFTc.The fractal dimensions of the transition pores,capillary pores,and macropores in the G3PM specimens first increase and then decrease as the number of SFTc increases.Among them,the capillary pores show the highest correlation with MLR and RDEM,with correlation coefficients of 0.97438 and 0.98555,respectively.展开更多
Tilted metasurface nanostructures,with excellent physical properties and enormous application potential,pose an urgent need for manufacturing methods.Here,electric-field-driven generative-nanoimprinting technique is p...Tilted metasurface nanostructures,with excellent physical properties and enormous application potential,pose an urgent need for manufacturing methods.Here,electric-field-driven generative-nanoimprinting technique is proposed.The electric field applied between the template and the substrate drives the contact,tilting,filling,and holding processes.By accurately controlling the introduced included angle between the flexible template and the substrate,tilted nanostructures with a controllable angle are imprinted onto the substrate,although they are vertical on the template.By flexibly adjusting the electric field intensity and the included angle,large-area uniform-tilted,gradient-tilted,and high-angle-tilted nanostructures are fabricated.In contrast to traditional replication,the morphology of the nanoimprinting structure is extended to customized control.This work provides a cost-effective,efficient,and versatile technology for the fabrication of various large-area tilted metasurface structures.As an illustration,a tilted nanograting with a high coupling efficiency is fabricated and integrated into augmented reality displays,demonstrating superior imaging quality.展开更多
AIM:To investigate the effects of shortening the duration of silicone oil tamponade on retinal structure and function in patients undergoing silicone oil removal(SOR)after surgery for primary rhegmatogenous retinal de...AIM:To investigate the effects of shortening the duration of silicone oil tamponade on retinal structure and function in patients undergoing silicone oil removal(SOR)after surgery for primary rhegmatogenous retinal detachment(RRD).METHODS:A total of 58 eligible patients were enrolled and randomly assigned to two groups based on tamponade duration:the short-term group(30-45d)and the conventional group(≥90d).Comprehensive evaluations were performed before and after SOR,including slitlamp examination,best-corrected visual acuity(BCVA)measurement,intraocular pressure(IOP)testing,optical coherence tomography(OCT),optical coherence tomography angiography(OCTA),microperimetry,electroretinography(ERG),and visual evoked potential(VEP)assessment.RESULTS:A total of 33 patients(23 males and 10 females;33 eyes)were enrolled in the short-term SO tamponade group with mean age of 52.45±9.35y,and 25 patients(15 males and 10 females;25 eyes)were enrolled in the conventional SO tamponade group with mean age of 50.80±12.06y.Compared with the conventional group,the short-term silicone oil tamponade group had a significantly lower incidence of silicone oil emulsification and cataract progression,with no significant difference in retinal reattachment success rate.Structurally,short-term tamponade was associated with increased thickness of the retinal ganglion cell layer(RGCL)in the nasal and superior macular regions and improved recovery of superficial retinal vascular density in these areas.Functionally,the shortterm group showed better BCVA and retinal sensitivity both before and 1mo after SOR;additionally,the P100 amplitude in VEP tests was significantly increased in this group.CONCLUSION:Shortening the duration of silicone oil tamponade effectively reduces damage to retinal structure and function without compromising the success rate of retinal reattachment in patients with primary RRD.展开更多
The infinite-layer nickelates,proposed as analogs to superconducting cuprates,provide a promising platform for exploring the mechanisms of unconventional superconductivity.However,the superconductivity has been exclus...The infinite-layer nickelates,proposed as analogs to superconducting cuprates,provide a promising platform for exploring the mechanisms of unconventional superconductivity.However,the superconductivity has been exclusively observed in thin films under atmospheric pressure,underscoring the critical role of the heterointerface.展开更多
Fast,precise structure determination of unknown compounds has been the foundation but with a persistent challenge in the field of chemical research.Among various chemical characterization techniques,single-crystal X-r...Fast,precise structure determination of unknown compounds has been the foundation but with a persistent challenge in the field of chemical research.Among various chemical characterization techniques,single-crystal X-ray diffraction(SCXRD)stands out as the most straightforward and accurate method in modern structural chemistry.By precisely determining the three-dimensional arrangement of atoms within a crystal,it provides direct atomic-level evidence for understanding the relationship between material structure and properties[1].展开更多
For deep prospects in the foreland thrust belt,southern Junggar Basin,NW China,there are uncertainties in factors controlling the structural deformation,distribution of paleo-structures and detachment layers,and distr...For deep prospects in the foreland thrust belt,southern Junggar Basin,NW China,there are uncertainties in factors controlling the structural deformation,distribution of paleo-structures and detachment layers,and distribution of major hydrocarbon source rocks.Based on the latest 3D seismic,gravity-magnetic,and drilling data,together with the results of previous structural physical simulation and discrete element numerical simulation experiments,the spatial distribution of pre-existing paleo-structures and detachment layers in deep strata of southern Junggar Basin were systematically characterized,the structural deformation characteristics and formation mechanisms were analyzed,the distribution patterns of multiple hydrocarbon source rock suites were clarified,and hydrocarbon accumulation features in key zones were reassessed.The exploration targets in deep lower assemblages with possibility of breakthrough were expected.Key results are obtained in three aspects.First,structural deformation is controlled by two-stage paleo-structures and three detachment layers with distinct lateral variations:the Jurassic layer(moderate thickness,wide distribution),the Cretaceous layer(thickest but weak detachment),and the Paleogene layer(thin but long-distance lateral thrusting).Accordingly,a four-layer composite deformation sequence was identified,and the structural genetic model with paleo-bulge controlling zonation by segments laterally and multiple detachment layers controlling sequence vertically.Second,the Permian source rocks show a distribution pattern with narrow trough(west),multiple sags(central),and broad basin(east),which is depicted by combining high-precision gravity-magnetic data and time-frequency electromagnetic data for the first time,and the Jurassic source rocks feature thicker mudstones in the west and rich coals in the east according to the reassessment.Third,two petroleum systems and a four-layer composite hydrocarbon accumulation model are established depending on the structural deformation strength,trap effectiveness and source-trap configuration.The southern Junggar Basin is divided into three segments with ten zones,and a hierarchical exploration strategy is proposed for deep lower assemblages in this region,that is,focusing on five priority zones,expanding to three potential areas,and challenging two high-risk targets.展开更多
Triggering structural asymmetry can induce charge redistribution and modify electronic structures,which is of great significance for the design of high-performance hydrogen oxidation reaction(HOR)electrocatalysts.Here...Triggering structural asymmetry can induce charge redistribution and modify electronic structures,which is of great significance for the design of high-performance hydrogen oxidation reaction(HOR)electrocatalysts.Herein,we propose a dual anion-induced strategy to create an innovative RuS_(2)-RuO_(2)heterostructure featuring abundant S-Ru-O interfaces(RuS_(2)-RuO_(2)@C).This RuS_(2)-RuO_(2)@C demonstrates an impressive mass activity of 2.61 mAμg_(RU)^(-1)and an exchange current density of 2.96 mA cm^(-2),surpassing Pt/C and other comparative samples by over 20 times.Durability assessments confirm the superior stability of RuS_(2)-RuO_(2)@C,with only minimal performance loss during operation.Density functional theory(DFT)calculations indicate that the asymmetric S-Ru-O configuration optimizes the interfacial electronic structure and shifts the d-band center closer to the Fermi level,effectively reducing the energy barrier of the rate-determining step(RDS)in the alkaline HOR process.Moreover,in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS)characteristics disclose the formation of a substantial hydrogen bond network at the S-Ru-o interface,which aids in the desorption of H_(2)O_(ad)and facilitates the vital Volmer step in the HOR pathway.展开更多
Over the past few years,major investments have been directed toward building new railway lines and upgrading existing ones.Many of these lines include critical infrastructure where operational and safety conditions mu...Over the past few years,major investments have been directed toward building new railway lines and upgrading existing ones.Many of these lines include critical infrastructure where operational and safety conditions must be carefully considered throughout their life cycle.Recent advancements in science and technology have enabled more effective structural monitoring of railway systems,largely driven by the adoption of intelligent strategies for inspection,maintenance,monitoring,and risk management.Research continues to expand and deepen the knowledge in this area;however,it remains a challenging field due to factors such as the complexity of railway systems,the high cost of implementation,and the need for reliable long-term data.展开更多
As the proportion of composite materials used in aircraft continues to increase, the electromagnetic Shielding Effectiveness (SE) of these materials becomes a critical factor in the electromagnetic safety design of ai...As the proportion of composite materials used in aircraft continues to increase, the electromagnetic Shielding Effectiveness (SE) of these materials becomes a critical factor in the electromagnetic safety design of aircraft structures. The assessment of electromagnetic SE for Slotted Composite Structures(SCSs) is particularly challenging due to their complex geometries and there remains a lack of suitable models for accurately predicting the SE performance of these intricate configurations. To address this issue, this paper introduces SCS-Net, a Deep Neural Network (DNN) method designed to accurately predict the SE of SCS. This method considers the impacts of various structural parameters, material properties and incident wave parameters on the SE of SCSs. In order to better model the SCS, an improved Nicolson-Ross-Weir (NRW) method is introduced in this paper to provide an equivalent flat structure for the SCS and to calculate the electromagnetic parameters of the equivalent structure. Additionally, the prediction of SE via DNNs is limited by insufficient test data, which hinders support for large-sample training. To address the issue of limited measured data, this paper develops a Measurement-Computation Fusion (MCF) dataset construction method. The predictions based on the simulation results show that the proposed method maintains an error of less than 0.07 dB within the 8–10 GHz frequency range. Furthermore, a new loss function based on the weighted L1-norm is established to improve the prediction accuracy for these parameters. Compared with traditional loss functions, the new loss function reduces the maximum prediction error for equivalent electromagnetic parameters by 47%. This method significantly improves the prediction accuracy of SCS-Net for measured data, with a maximum improvement of 23.88%. These findings demonstrate that the proposed method enables precise SE prediction and design for composite structures while reducing the number of test samples needed.展开更多
To ensure the structural integrity of life-limiting component of aeroengines,Probabilistic Damage Tolerance(PDT)assessment is applied to evaluate the failure risk as required by airworthiness regulations and military ...To ensure the structural integrity of life-limiting component of aeroengines,Probabilistic Damage Tolerance(PDT)assessment is applied to evaluate the failure risk as required by airworthiness regulations and military standards.The PDT method holds the view that there exist defects such as machining scratches and service cracks in the tenon-groove structures of aeroengine disks.However,it is challenging to conduct PDT assessment due to the scarcity of effective Probability of Detection(POD)model and anomaly distribution model.Through a series of Nondestructive Testing(NDT)experiments,the POD model of real cracks in tenon-groove structures is constructed for the first time by employing the Transfer Function Method(TFM).A novel anomaly distribution model is derived through the utilization of the POD model,instead of using the infeasible field data accumulation method.Subsequently,a framework for calculating the Probability of Failure(POF)of the tenon-groove structures is established,and the aforementioned two models exert a significant influence on the results of POF.展开更多
The stability and electrocatalytic efficiency of transition metal oxides for water splitting is determined by geometric and electronic structure,especially under high current densities.Herein,a newly designed lamella-...The stability and electrocatalytic efficiency of transition metal oxides for water splitting is determined by geometric and electronic structure,especially under high current densities.Herein,a newly designed lamella-heterostructured nanoporous CoFe/CoFe_(2)O_(4) and CeO_(2−x),in situ grown on nickel foam(NF),holds great promise as a high-efficient bifunctional electrocatalyst(named R-CoFe/Ce/NF)for water splitting.Experimental characterization verifies surface reconstruction from CoFe alloy/oxide to highly active CoFeOOH during in situ electrochemical polarization.By virtues of three-dimensional nanoporous architecture and abundant electroactive CoFeOOH/CeO_(2−x) heterostructure interfaces,the R-CoFe/Ce/NF electrode achieves low overpotentials for oxygen evolution(η_(10)=227 mV;η_(500)=450 mV)and hydrogen evolution(η_(10)=35 mV;η_(408)=560 mV)reactions with high normalized electrochemical active surface areas,respectively.Additionally,the alkaline full water splitting electrolyzer of R-CoFe/Ce/NF||R-CoFe/Ce/NF achieves a current density of 50 mA·cm^(−2) only at 1.75 V;the decline of activity is satisfactory after 100-h durability test at 300 mA·cm^(−2).Density functional theory also demonstrates that the electron can transfer from CeO_(2−x) by virtue of O atom to CoFeOOH at CoFeOOH/CeO_(2−x) heterointerfaces and enhancing the adsorption of reactant,thus optimizing electronic structure and Gibbs free energies for the improvement of the activity for water splitting.展开更多
Ferroelastic rare earth tantalates(RETaO_(4))are widely researched as the next-generation thermal barrier coatings(TBCs),and RETaO_(4)powders are hugely significant for synthesizing their coatings.The current research...Ferroelastic rare earth tantalates(RETaO_(4))are widely researched as the next-generation thermal barrier coatings(TBCs),and RETaO_(4)powders are hugely significant for synthesizing their coatings.The current research used chemical co-precipitation within an automated experimental device to synthesize RETaO_(4)(RE=Nd,Sm,Gd,Ho,Er)powders.The device automatically monitored and controlled the solutions'pH,improving the chemical co-precipitation efficiency.The crystal structure and microstructure of the RETaO_(4)powders can be controlled by changing the annealing temperature,and the materials undergo an m'-m phase transition.The m'-RETaO_(4)powders exhibit nano-size grains,while m-RETaO_(4)powders evince micron-size grains,altered by the annealing temperatures.A simultaneous thermal analysis es-timates the reversive ferroelastic tetragonal-monoclinic phase transition temperatures.Overall,this research focuses on the synthesis,crystal structures,microstructures,and phase transition of the fabricated RETaO_(4)powders.展开更多
Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storag...Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storage systems.Among the numerous types of SSEs,inorganic oxide garnet-structured superionic conductors Li7La3Zr2O12(LLZO)crystallized with the cubic Iaˉ3d space group have received considerable attention owing to their highly advantageous intrinsic properties encompassing reasonable lithium-ion conductivity,wide electrochemical voltage window,high shear modulus,and excellent chemical stability with electrodes.However,no SSEs possess all the properties necessary for SSLBs,thus both the ionic conductivity at room temperature and stability in ambient air regarding cubic garnet-based electrolytes are still subject to further improvement.Hence,this review comprehensively covers the nine key structural factors affecting the ion conductivity of garnet-based electrolytes comprising Li concentration,Li vacancy concentration,Li carrier concentration and mobility,Li occupancy at available sites,lattice constant,triangle bottleneck size,oxygen vacancy defects,and Li-O bonding interactions.Furthermore,the general illustration of structures and fundamental features being crucial to chemical stability is examined,including Li concentration,Li-site occupation behavior,and Li-O bonding interactions.Insights into the composition-structure-property relations among cubic garnet-based oxide ionic conductors from the perspective of their crystal structures,revealing the potential compatibility conflicts between ionic transportation and chemical stability resulting from Li-O bonding interactions.We believe that this review will lay the foundation for future reasonable structural design of oxide-based or even other types of superionic conductors,thus assisting in promoting the rapid development of alternative green and sustainable technologies.展开更多
Polymeric perylene diimide(PDI)has been evidenced as a good candidate for photocatalytic water oxidation,yet the origin of the photocatalytic oxygen evolution activity remains unclear and needs further exploration.Her...Polymeric perylene diimide(PDI)has been evidenced as a good candidate for photocatalytic water oxidation,yet the origin of the photocatalytic oxygen evolution activity remains unclear and needs further exploration.Herein,with crystal and atomic structures of the self-assembled PDI revealed from the X-ray diffraction pattern,the electronic structure is theoretically illustrated by the first-principles density functional theory calculations,suggesting the suitable band structure and the direct electronic transition for efficient photocatalytic oxygen evolution over PDI.It is confirmed that the carbonyl O atoms on the conjugation structure serve as the active sites for oxygen evolution reaction by the crystal orbital Hamiltonian group analysis.The calculations of reaction free energy changes indicate that the oxygen evolution reaction should follow the reaction pathway of H_(2)O→^(*)OH→^(*)O→^(*)OOH→^(*)O_(2)with an overpotential of 0.81 V.Through an in-depth theoretical computational analysis in the atomic and electronic structures,the origin of photocatalytic oxygen evolution activity for PDI is well illustrated,which would help the rational design and modification of polymeric photocatalysts for efficient oxygen evolution.展开更多
The development of high-performance structural and functional materials is vital in many industrial fields.High-and medium-entropy alloys(H/MEAs)with superior comprehensive properties owing to their specific microstru...The development of high-performance structural and functional materials is vital in many industrial fields.High-and medium-entropy alloys(H/MEAs)with superior comprehensive properties owing to their specific microstructures are promising candidates for structural materials.More importantly,multitudinous efforts have been made to regulate the microstructures and the properties of H/MEAs to further expand their industrial applications.The various heterostructures have enormous potential for the development of H/MEAs with outstanding performance.Herein,multiple heterogeneous structures with single and hierarchical heterogeneities were discussed in detail.Moreover,preparation methods for compositional inhomogeneity,bimodal structures,dualphase structures,lamella/layered structures,harmonic structures(core-shell),multiscale precipitates and heterostructures coupled with specific microstructures in H/MEAs were also systematically reviewed.The deformation mechanisms induced by the different heterostructures were thoroughly discussed to explore the relationship between the heterostructures and the optimized properties of H/MEAs.The contributions of the heterostructures and advanced microstructures to the H/MEAs were comprehensively elucidated to further improve the properties of the alloys.Finally,this review discussed the future challenges of high-performance H/MEAs for industrial applications and provides feasible methods for optimizing heterostructures to enhance the comprehensive properties of H/MEAs.展开更多
The microstructure of the 18R-type long period stacking ordered （LPSO） phase in Mg 97 Y 2 Zn 1 alloy was investigated by the first principles calculation. The arrangement rule of Zn and Y atoms in the LPSO structure...The microstructure of the 18R-type long period stacking ordered （LPSO） phase in Mg 97 Y 2 Zn 1 alloy was investigated by the first principles calculation. The arrangement rule of Zn and Y atoms in the LPSO structure is determined theoretically. The calculation results reveal that the additive atoms are firstly located in the fault layers at the two ends of the 18R-type LPSO structure, and then extend to fault layers in the interior, which is in good agreement with the experimental observations. This feature also implies the microstructural relationship between 18R and other LPSO structures. The cohesive energy and the formation heat indicate the dependence of the stability of 18R LPSO structure on contents of Y and Zn atoms. The calculated electronic structures reveal the underlying mechanism of microstructure and the stability of 18R LPSO structure.展开更多
Wenhao Wang and colleagues summarized the latest advancements in structural color research in Opto-Electronic Science. Their review explored the fundamental principles and fabrication methods of structural colors for ...Wenhao Wang and colleagues summarized the latest advancements in structural color research in Opto-Electronic Science. Their review explored the fundamental principles and fabrication methods of structural colors for photonic applications, including anti-counterfeiting, displays, sensors, and printing, along with their practical limitations. Recently, structural colors have received growing interest due to their advantages, including physical and chemical robustness, ecofriendliness, tunability, and high-resolution color.展开更多
The Longmenshan structural belt on the eastern edge of the Tibetan Plateau experienced the impactful Mw7.92008 Wenchuan Earthquake,causing a 350 km surface rupture.Traditional models attribute this to the Beichuan and...The Longmenshan structural belt on the eastern edge of the Tibetan Plateau experienced the impactful Mw7.92008 Wenchuan Earthquake,causing a 350 km surface rupture.Traditional models attribute this to the Beichuan and Pengguan faults,but our research reveals a complex fault system at the northern end,with inconsistencies in surface rupture,aftershock distribution,and focal mechanisms.We integrate shallow geology,active source seismic reflection,and magnetotelluric profiling to establish a deep structural model for the northern end of the Longmenshan structural belt.This area exhibits dominant reverse thrust nappe tectonics,and analyzing the tectonic evolution history provides insights into deformation propagation from the orogenic belt toward the Sichuan Basin.Focal mechanism analysis and relocated aftershock data reveals two distinct types of seismogenic structures in the northern end of the Longmenshan structural belt.In the middle to northern segments,the reverse fault type is attributed to reactivated pre-existing faults.Conversely,at the northern end,the strike-slip fault type originates from high-angle co-seismic rupture cutting through pre-existing reverse faults.This study enhances our understanding of fault complexity and seismic mechanisms in the northeastern Longmenshan structural belt,providing new insights into regional tectonics.展开更多
基金Supported by the Science and Technology Cooperation and Exchange special project of Cooperation of Shanxi Province(202404041101014)the Fundamental Research Program of Shanxi Province(202403021212333)+3 种基金the Joint Funds of the National Natural Science Foundation of China(U24A20555)the Lvliang Key R&D of University-Local Cooperation(2023XDHZ10)the Initiation Fund for Doctoral Research of Taiyuan University of Science and Technology(20242026)the Outstanding Doctor Funding Award of Shanxi Province(20242080).
文摘To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.
基金Supported by the National Key Research Program(No.2024-1129-954-112)National Natural Science Foundation of China(No.52372033)Guangxi Science and Technology Major Program(No.AA24263054)。
文摘Alkali-free SiO_(2)-Al_(2)O_(3)-CaO-MgO with different SiO_(2)/Al_(2)O_(3)mass ratios was prepared by conventional melt quenching method.The glass network structure,thermodynamic properties and elastic modulus changes with SiO_(2)and Al_(2)O_(3)ratios were investigated using various techniques.It is found that when SiO_(2)is replaced by Al_(2)O_(3),the Q^(4) to Q^(3) transition of silicon-oxygen network decreases while the aluminum-oxygen network increases,which result in the transformation of Si-O-Si bonds to Si-O-Al bonds and an increase in glass network connectivity even though the intermolecular bond strength decreases.The glass transition temperature(T_(g))increases continuously,while the thermal expansion coefficient increases and high-temperature viscosity first decreases and then increases.Meanwhile,the elastic modulus values increase from 93 to 102 GPa.This indicates that the elastic modulus is mainly affected by packing factor and dissociation energy,and elements with higher packing factors and dissociation energies supplant those with lower values,resulting in increased rigidity within the glass.
基金Funded by the National Natural Science Foundation of China(Nos.5226804252468035)。
文摘To investigate the pore structure of graphene oxide modified polymer cement mortar(GOPM)under salt-freeze-thaw(SFT)coupling effects and its impact on deterioration,this study modifies polymer cement mortar(EMCM)with graphene oxide(GO).The micro-pore structure of GOPM is characterized using LF-NMR and SEM.Fractal theory is applied to calculate the fractal dimension of pore volume,and the deterioration patterns are analyzed based on the evolution characteristics of capillary pores.The experimental results indicate that,after 25 salt-freeze-thaw cycles(SFTc),SO2-4 ions penetrate the matrix,generating corrosion products that fill existing pores and enhance the compactness of the specimen.As the number of cycles increases,the ongoing formation and expansion of corrosion products within the matrix,combined with persistent freezing forces,and result in the degradation of the pore structure.Therefore,the mass loss rate(MLR)of the specimens shows a trend of first decreasing and then increasing,while the relative dynamic elastic modulus(RDEM)initially increases and then decreases.Compared to the PC group specimens,the G3PM group specimens show a 28.71% reduction in MLR and a 31.42% increase in RDEM after 150 SFTc.The fractal dimensions of the transition pores,capillary pores,and macropores in the G3PM specimens first increase and then decrease as the number of SFTc increases.Among them,the capillary pores show the highest correlation with MLR and RDEM,with correlation coefficients of 0.97438 and 0.98555,respectively.
基金supported by National Natural Science Foundation of China(No.52025055 and 52275571)Basic Research Operation Fund of China(No.xzy012024024).
文摘Tilted metasurface nanostructures,with excellent physical properties and enormous application potential,pose an urgent need for manufacturing methods.Here,electric-field-driven generative-nanoimprinting technique is proposed.The electric field applied between the template and the substrate drives the contact,tilting,filling,and holding processes.By accurately controlling the introduced included angle between the flexible template and the substrate,tilted nanostructures with a controllable angle are imprinted onto the substrate,although they are vertical on the template.By flexibly adjusting the electric field intensity and the included angle,large-area uniform-tilted,gradient-tilted,and high-angle-tilted nanostructures are fabricated.In contrast to traditional replication,the morphology of the nanoimprinting structure is extended to customized control.This work provides a cost-effective,efficient,and versatile technology for the fabrication of various large-area tilted metasurface structures.As an illustration,a tilted nanograting with a high coupling efficiency is fabricated and integrated into augmented reality displays,demonstrating superior imaging quality.
基金Supported by the Key Science&Technology Project of Guangzhou(No.202103000045)the National Natural Science Foundation of China(No.82070972,No.82271093).
文摘AIM:To investigate the effects of shortening the duration of silicone oil tamponade on retinal structure and function in patients undergoing silicone oil removal(SOR)after surgery for primary rhegmatogenous retinal detachment(RRD).METHODS:A total of 58 eligible patients were enrolled and randomly assigned to two groups based on tamponade duration:the short-term group(30-45d)and the conventional group(≥90d).Comprehensive evaluations were performed before and after SOR,including slitlamp examination,best-corrected visual acuity(BCVA)measurement,intraocular pressure(IOP)testing,optical coherence tomography(OCT),optical coherence tomography angiography(OCTA),microperimetry,electroretinography(ERG),and visual evoked potential(VEP)assessment.RESULTS:A total of 33 patients(23 males and 10 females;33 eyes)were enrolled in the short-term SO tamponade group with mean age of 52.45±9.35y,and 25 patients(15 males and 10 females;25 eyes)were enrolled in the conventional SO tamponade group with mean age of 50.80±12.06y.Compared with the conventional group,the short-term silicone oil tamponade group had a significantly lower incidence of silicone oil emulsification and cataract progression,with no significant difference in retinal reattachment success rate.Structurally,short-term tamponade was associated with increased thickness of the retinal ganglion cell layer(RGCL)in the nasal and superior macular regions and improved recovery of superficial retinal vascular density in these areas.Functionally,the shortterm group showed better BCVA and retinal sensitivity both before and 1mo after SOR;additionally,the P100 amplitude in VEP tests was significantly increased in this group.CONCLUSION:Shortening the duration of silicone oil tamponade effectively reduces damage to retinal structure and function without compromising the success rate of retinal reattachment in patients with primary RRD.
基金supported by the National Natural Science Foundation of China[52125307(to P.G.),12404192(to R.C.S),12274061(to L.Q.)]Key Research and Development Program from the Ministry of Science and Technology(2023YFA1406301)the support from the New Cornerstone Science Foundation through the XPLORER PRIZE。
文摘The infinite-layer nickelates,proposed as analogs to superconducting cuprates,provide a promising platform for exploring the mechanisms of unconventional superconductivity.However,the superconductivity has been exclusively observed in thin films under atmospheric pressure,underscoring the critical role of the heterointerface.
基金the National Natural Science Foundation of China(Nos.22471014 and 22271013)the Beijing Natural Science Foundation(No.2232024)for financial support.
文摘Fast,precise structure determination of unknown compounds has been the foundation but with a persistent challenge in the field of chemical research.Among various chemical characterization techniques,single-crystal X-ray diffraction(SCXRD)stands out as the most straightforward and accurate method in modern structural chemistry.By precisely determining the three-dimensional arrangement of atoms within a crystal,it provides direct atomic-level evidence for understanding the relationship between material structure and properties[1].
基金Supported by the Science and Technology Special Project of CNPC(2023YQX10111)Key Research and Development Special Project of Xinjiang Uygur Autonomous Region(2024B01015-3)。
文摘For deep prospects in the foreland thrust belt,southern Junggar Basin,NW China,there are uncertainties in factors controlling the structural deformation,distribution of paleo-structures and detachment layers,and distribution of major hydrocarbon source rocks.Based on the latest 3D seismic,gravity-magnetic,and drilling data,together with the results of previous structural physical simulation and discrete element numerical simulation experiments,the spatial distribution of pre-existing paleo-structures and detachment layers in deep strata of southern Junggar Basin were systematically characterized,the structural deformation characteristics and formation mechanisms were analyzed,the distribution patterns of multiple hydrocarbon source rock suites were clarified,and hydrocarbon accumulation features in key zones were reassessed.The exploration targets in deep lower assemblages with possibility of breakthrough were expected.Key results are obtained in three aspects.First,structural deformation is controlled by two-stage paleo-structures and three detachment layers with distinct lateral variations:the Jurassic layer(moderate thickness,wide distribution),the Cretaceous layer(thickest but weak detachment),and the Paleogene layer(thin but long-distance lateral thrusting).Accordingly,a four-layer composite deformation sequence was identified,and the structural genetic model with paleo-bulge controlling zonation by segments laterally and multiple detachment layers controlling sequence vertically.Second,the Permian source rocks show a distribution pattern with narrow trough(west),multiple sags(central),and broad basin(east),which is depicted by combining high-precision gravity-magnetic data and time-frequency electromagnetic data for the first time,and the Jurassic source rocks feature thicker mudstones in the west and rich coals in the east according to the reassessment.Third,two petroleum systems and a four-layer composite hydrocarbon accumulation model are established depending on the structural deformation strength,trap effectiveness and source-trap configuration.The southern Junggar Basin is divided into three segments with ten zones,and a hierarchical exploration strategy is proposed for deep lower assemblages in this region,that is,focusing on five priority zones,expanding to three potential areas,and challenging two high-risk targets.
基金supported by the National Natural Science Foundation of China(no.52363028,21965005)the Natural Science Foundation of Guangxi Province(2021GXNSFAA076001,2018GXNSFAA294077)the Guangxi Technology Base and Talent Subject(GUIKE AD23023004,GUIKE AD20297039).
文摘Triggering structural asymmetry can induce charge redistribution and modify electronic structures,which is of great significance for the design of high-performance hydrogen oxidation reaction(HOR)electrocatalysts.Herein,we propose a dual anion-induced strategy to create an innovative RuS_(2)-RuO_(2)heterostructure featuring abundant S-Ru-O interfaces(RuS_(2)-RuO_(2)@C).This RuS_(2)-RuO_(2)@C demonstrates an impressive mass activity of 2.61 mAμg_(RU)^(-1)and an exchange current density of 2.96 mA cm^(-2),surpassing Pt/C and other comparative samples by over 20 times.Durability assessments confirm the superior stability of RuS_(2)-RuO_(2)@C,with only minimal performance loss during operation.Density functional theory(DFT)calculations indicate that the asymmetric S-Ru-O configuration optimizes the interfacial electronic structure and shifts the d-band center closer to the Fermi level,effectively reducing the energy barrier of the rate-determining step(RDS)in the alkaline HOR process.Moreover,in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy(ATR-SEIRAS)characteristics disclose the formation of a substantial hydrogen bond network at the S-Ru-o interface,which aids in the desorption of H_(2)O_(ad)and facilitates the vital Volmer step in the HOR pathway.
文摘Over the past few years,major investments have been directed toward building new railway lines and upgrading existing ones.Many of these lines include critical infrastructure where operational and safety conditions must be carefully considered throughout their life cycle.Recent advancements in science and technology have enabled more effective structural monitoring of railway systems,largely driven by the adoption of intelligent strategies for inspection,maintenance,monitoring,and risk management.Research continues to expand and deepen the knowledge in this area;however,it remains a challenging field due to factors such as the complexity of railway systems,the high cost of implementation,and the need for reliable long-term data.
基金supported by the National Natural Science Foundation of China(Nos.62101020 and 62141405)the Special Scientific Research Project of Civil Aircraft,China(No.MJZ5-2N22).
文摘As the proportion of composite materials used in aircraft continues to increase, the electromagnetic Shielding Effectiveness (SE) of these materials becomes a critical factor in the electromagnetic safety design of aircraft structures. The assessment of electromagnetic SE for Slotted Composite Structures(SCSs) is particularly challenging due to their complex geometries and there remains a lack of suitable models for accurately predicting the SE performance of these intricate configurations. To address this issue, this paper introduces SCS-Net, a Deep Neural Network (DNN) method designed to accurately predict the SE of SCS. This method considers the impacts of various structural parameters, material properties and incident wave parameters on the SE of SCSs. In order to better model the SCS, an improved Nicolson-Ross-Weir (NRW) method is introduced in this paper to provide an equivalent flat structure for the SCS and to calculate the electromagnetic parameters of the equivalent structure. Additionally, the prediction of SE via DNNs is limited by insufficient test data, which hinders support for large-sample training. To address the issue of limited measured data, this paper develops a Measurement-Computation Fusion (MCF) dataset construction method. The predictions based on the simulation results show that the proposed method maintains an error of less than 0.07 dB within the 8–10 GHz frequency range. Furthermore, a new loss function based on the weighted L1-norm is established to improve the prediction accuracy for these parameters. Compared with traditional loss functions, the new loss function reduces the maximum prediction error for equivalent electromagnetic parameters by 47%. This method significantly improves the prediction accuracy of SCS-Net for measured data, with a maximum improvement of 23.88%. These findings demonstrate that the proposed method enables precise SE prediction and design for composite structures while reducing the number of test samples needed.
基金supported by the National Major Science and Technology Project,China(No.J2019-Ⅳ-0007-0075)the Fundamental Research Funds for the Central Universities,China(No.JKF-20240036)。
文摘To ensure the structural integrity of life-limiting component of aeroengines,Probabilistic Damage Tolerance(PDT)assessment is applied to evaluate the failure risk as required by airworthiness regulations and military standards.The PDT method holds the view that there exist defects such as machining scratches and service cracks in the tenon-groove structures of aeroengine disks.However,it is challenging to conduct PDT assessment due to the scarcity of effective Probability of Detection(POD)model and anomaly distribution model.Through a series of Nondestructive Testing(NDT)experiments,the POD model of real cracks in tenon-groove structures is constructed for the first time by employing the Transfer Function Method(TFM).A novel anomaly distribution model is derived through the utilization of the POD model,instead of using the infeasible field data accumulation method.Subsequently,a framework for calculating the Probability of Failure(POF)of the tenon-groove structures is established,and the aforementioned two models exert a significant influence on the results of POF.
基金sponsored by the National Natural Science Foundation of China(Nos.5210125 and 52375422)the Science Research Project of Hebei Education Department(No.BJK2023058)the Natural Science Foundation of Hebei Province(Nos.E2020208069,B2020208083 and E202320801).
文摘The stability and electrocatalytic efficiency of transition metal oxides for water splitting is determined by geometric and electronic structure,especially under high current densities.Herein,a newly designed lamella-heterostructured nanoporous CoFe/CoFe_(2)O_(4) and CeO_(2−x),in situ grown on nickel foam(NF),holds great promise as a high-efficient bifunctional electrocatalyst(named R-CoFe/Ce/NF)for water splitting.Experimental characterization verifies surface reconstruction from CoFe alloy/oxide to highly active CoFeOOH during in situ electrochemical polarization.By virtues of three-dimensional nanoporous architecture and abundant electroactive CoFeOOH/CeO_(2−x) heterostructure interfaces,the R-CoFe/Ce/NF electrode achieves low overpotentials for oxygen evolution(η_(10)=227 mV;η_(500)=450 mV)and hydrogen evolution(η_(10)=35 mV;η_(408)=560 mV)reactions with high normalized electrochemical active surface areas,respectively.Additionally,the alkaline full water splitting electrolyzer of R-CoFe/Ce/NF||R-CoFe/Ce/NF achieves a current density of 50 mA·cm^(−2) only at 1.75 V;the decline of activity is satisfactory after 100-h durability test at 300 mA·cm^(−2).Density functional theory also demonstrates that the electron can transfer from CeO_(2−x) by virtue of O atom to CoFeOOH at CoFeOOH/CeO_(2−x) heterointerfaces and enhancing the adsorption of reactant,thus optimizing electronic structure and Gibbs free energies for the improvement of the activity for water splitting.
基金the Rare and Precious Metals Material Genetic Engineering Project of Yunnan Province(202102AB080019-1)National Key Research and Development Program of China(2022YFB3708600)the National Natural Science Foundation of China(91960103).
文摘Ferroelastic rare earth tantalates(RETaO_(4))are widely researched as the next-generation thermal barrier coatings(TBCs),and RETaO_(4)powders are hugely significant for synthesizing their coatings.The current research used chemical co-precipitation within an automated experimental device to synthesize RETaO_(4)(RE=Nd,Sm,Gd,Ho,Er)powders.The device automatically monitored and controlled the solutions'pH,improving the chemical co-precipitation efficiency.The crystal structure and microstructure of the RETaO_(4)powders can be controlled by changing the annealing temperature,and the materials undergo an m'-m phase transition.The m'-RETaO_(4)powders exhibit nano-size grains,while m-RETaO_(4)powders evince micron-size grains,altered by the annealing temperatures.A simultaneous thermal analysis es-timates the reversive ferroelastic tetragonal-monoclinic phase transition temperatures.Overall,this research focuses on the synthesis,crystal structures,microstructures,and phase transition of the fabricated RETaO_(4)powders.
基金supported by the National Natural Science Foundation of China(Nos.22171102 and 22090044)the National Key R&D Program of China(Nos.2021YFF0500502 and 2023YFA1506304)+2 种基金the Jilin Province Science and Technology Development Plan(No.20230101024JC)the"Medicine+X"crossinnovation team of Bethune Medical Department of Jilin University"Leading the Charge with Open Competition"construction project(No.2022JBGS04)the Jilin University Graduate Training Office(Nos.2021JGZ08 and 2022YJSJIP20).
文摘Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storage systems.Among the numerous types of SSEs,inorganic oxide garnet-structured superionic conductors Li7La3Zr2O12(LLZO)crystallized with the cubic Iaˉ3d space group have received considerable attention owing to their highly advantageous intrinsic properties encompassing reasonable lithium-ion conductivity,wide electrochemical voltage window,high shear modulus,and excellent chemical stability with electrodes.However,no SSEs possess all the properties necessary for SSLBs,thus both the ionic conductivity at room temperature and stability in ambient air regarding cubic garnet-based electrolytes are still subject to further improvement.Hence,this review comprehensively covers the nine key structural factors affecting the ion conductivity of garnet-based electrolytes comprising Li concentration,Li vacancy concentration,Li carrier concentration and mobility,Li occupancy at available sites,lattice constant,triangle bottleneck size,oxygen vacancy defects,and Li-O bonding interactions.Furthermore,the general illustration of structures and fundamental features being crucial to chemical stability is examined,including Li concentration,Li-site occupation behavior,and Li-O bonding interactions.Insights into the composition-structure-property relations among cubic garnet-based oxide ionic conductors from the perspective of their crystal structures,revealing the potential compatibility conflicts between ionic transportation and chemical stability resulting from Li-O bonding interactions.We believe that this review will lay the foundation for future reasonable structural design of oxide-based or even other types of superionic conductors,thus assisting in promoting the rapid development of alternative green and sustainable technologies.
基金supported by National Natural Science Foundation of China(No.523B2070,No.52225606).
文摘Polymeric perylene diimide(PDI)has been evidenced as a good candidate for photocatalytic water oxidation,yet the origin of the photocatalytic oxygen evolution activity remains unclear and needs further exploration.Herein,with crystal and atomic structures of the self-assembled PDI revealed from the X-ray diffraction pattern,the electronic structure is theoretically illustrated by the first-principles density functional theory calculations,suggesting the suitable band structure and the direct electronic transition for efficient photocatalytic oxygen evolution over PDI.It is confirmed that the carbonyl O atoms on the conjugation structure serve as the active sites for oxygen evolution reaction by the crystal orbital Hamiltonian group analysis.The calculations of reaction free energy changes indicate that the oxygen evolution reaction should follow the reaction pathway of H_(2)O→^(*)OH→^(*)O→^(*)OOH→^(*)O_(2)with an overpotential of 0.81 V.Through an in-depth theoretical computational analysis in the atomic and electronic structures,the origin of photocatalytic oxygen evolution activity for PDI is well illustrated,which would help the rational design and modification of polymeric photocatalysts for efficient oxygen evolution.
基金National Natural Science Foundation of China(52261032,51861021,51661016)Science and Technology Plan of Gansu Province(21YF5GA074)+2 种基金Public Welfare Project of Zhejiang Natural Science Foundation(LGG22E010008)Wenzhou Basic Public Welfare Scientific Research Project(G2023020)Incubation Program of Excellent Doctoral Dissertation-Lanzhou University of Technology。
文摘The development of high-performance structural and functional materials is vital in many industrial fields.High-and medium-entropy alloys(H/MEAs)with superior comprehensive properties owing to their specific microstructures are promising candidates for structural materials.More importantly,multitudinous efforts have been made to regulate the microstructures and the properties of H/MEAs to further expand their industrial applications.The various heterostructures have enormous potential for the development of H/MEAs with outstanding performance.Herein,multiple heterogeneous structures with single and hierarchical heterogeneities were discussed in detail.Moreover,preparation methods for compositional inhomogeneity,bimodal structures,dualphase structures,lamella/layered structures,harmonic structures(core-shell),multiscale precipitates and heterostructures coupled with specific microstructures in H/MEAs were also systematically reviewed.The deformation mechanisms induced by the different heterostructures were thoroughly discussed to explore the relationship between the heterostructures and the optimized properties of H/MEAs.The contributions of the heterostructures and advanced microstructures to the H/MEAs were comprehensively elucidated to further improve the properties of the alloys.Finally,this review discussed the future challenges of high-performance H/MEAs for industrial applications and provides feasible methods for optimizing heterostructures to enhance the comprehensive properties of H/MEAs.
基金Projects(50861002,51071053)supported by the National Natural Science Foundation of ChinaProject(0991051)supported by NaturalScience Foundation of Guangxi Province,China+1 种基金Project(KF0803)supported by Open Project of Key Laboratory of Materials Design and Preparation Technology of Hunan Province,ChinaProject(X071117)supported by Scientific Research Foundation of Guangxi University,China
文摘The microstructure of the 18R-type long period stacking ordered （LPSO） phase in Mg 97 Y 2 Zn 1 alloy was investigated by the first principles calculation. The arrangement rule of Zn and Y atoms in the LPSO structure is determined theoretically. The calculation results reveal that the additive atoms are firstly located in the fault layers at the two ends of the 18R-type LPSO structure, and then extend to fault layers in the interior, which is in good agreement with the experimental observations. This feature also implies the microstructural relationship between 18R and other LPSO structures. The cohesive energy and the formation heat indicate the dependence of the stability of 18R LPSO structure on contents of Y and Zn atoms. The calculated electronic structures reveal the underlying mechanism of microstructure and the stability of 18R LPSO structure.
基金supported by the POSCO-POSTECH-RIST Convergence Research Center program funded by POSCOthe National Research Foundation(NRF)grants(RS-2022-NR067559,RS-2023-00302586)funded by the Ministry of Science and ICT(MSIT)of the Korean government.
文摘Wenhao Wang and colleagues summarized the latest advancements in structural color research in Opto-Electronic Science. Their review explored the fundamental principles and fabrication methods of structural colors for photonic applications, including anti-counterfeiting, displays, sensors, and printing, along with their practical limitations. Recently, structural colors have received growing interest due to their advantages, including physical and chemical robustness, ecofriendliness, tunability, and high-resolution color.
基金supported by the National Key Research and Development Project of China(No.2021YFC3000600)。
文摘The Longmenshan structural belt on the eastern edge of the Tibetan Plateau experienced the impactful Mw7.92008 Wenchuan Earthquake,causing a 350 km surface rupture.Traditional models attribute this to the Beichuan and Pengguan faults,but our research reveals a complex fault system at the northern end,with inconsistencies in surface rupture,aftershock distribution,and focal mechanisms.We integrate shallow geology,active source seismic reflection,and magnetotelluric profiling to establish a deep structural model for the northern end of the Longmenshan structural belt.This area exhibits dominant reverse thrust nappe tectonics,and analyzing the tectonic evolution history provides insights into deformation propagation from the orogenic belt toward the Sichuan Basin.Focal mechanism analysis and relocated aftershock data reveals two distinct types of seismogenic structures in the northern end of the Longmenshan structural belt.In the middle to northern segments,the reverse fault type is attributed to reactivated pre-existing faults.Conversely,at the northern end,the strike-slip fault type originates from high-angle co-seismic rupture cutting through pre-existing reverse faults.This study enhances our understanding of fault complexity and seismic mechanisms in the northeastern Longmenshan structural belt,providing new insights into regional tectonics.
