The surface reconstructing of vermicular alpha-alumina exposed under electron-beam irradiation was investigated by a scanning electron microscope with 0.5 keV beam energy and by a transmittance electron microscope at ...The surface reconstructing of vermicular alpha-alumina exposed under electron-beam irradiation was investigated by a scanning electron microscope with 0.5 keV beam energy and by a transmittance electron microscope at room temperature and 90 K, respectively. The in-situ recorded results showed that the present electron-beam-induced surface reconstructing was both electron dose and temperature dependent and accompanied by bulk shape change. The surface reconstruction was explained by an Auger decay process, in which surface composition constancy was proposed by the equilibrium between electron stmulated reduction of Al2O3 and oxidation of aluminum by desorbed oxygen from bulk.展开更多
Runway surface roughness significantly influences aircraft vibrations during takeoff and landing,affecting both flight safety and pavement durability.Aircraft operate at high speeds and wide gear spans,making them sen...Runway surface roughness significantly influences aircraft vibrations during takeoff and landing,affecting both flight safety and pavement durability.Aircraft operate at high speeds and wide gear spans,making them sensitive to long-wavelength(15–120 m)and lateral irregularities,which are often overlooked in traditional roughness models.This study aims to construct a three-dimensional runway roughness modeling framework integrating"precise detection-spectrum analysis-spatial reconstruction"in response to this issue.Combining the elevation data of 37 runways(5 asphalt runways and 32 cement runways)measured by a vehicle-mounted laser profilometer and the BeiDou positioning system,the power spectrum analysis was carried out by the Burg method and the spectrum models of asphalt and cement runways were fitted respectively.Meanwhile,a new exponential lateral coherence function was proposed.Finally,the three-dimensional spatial model was reconstructed by using the transfer function and genetic algorithm.The results show that the error of the measured elevation data is less than 1 cm.The spectral characteristics of different pavement types are significantly different.Among them,the R^(2) of the asphalt runway fitted with the Sussman model is greater than 0.9.The cement runway needs to be characterized by a piecewise function to represent the spectral mutation.The fitting error of the new index's lateral coherence function has been reduced to 0.012.The reconstructed three-dimensional model is in good agreement with the theoretical value and the error does not exceed 0.18 mm^(2) m/c.Finally,a three-dimensional model of 0–20 m in the lateral direction and 3000 m in the longitudinal direction is generated,providing support for aircraft vibration simulation and pavement maintenance.展开更多
The rationally designed ruthenium selenide(RuSe_(1.6)-500)nanocomposite with selenium vacancies was synthesized via a hydrothermal/annealing approach.During the annealing step,calcination under a H_(2)/Ar atmosphere f...The rationally designed ruthenium selenide(RuSe_(1.6)-500)nanocomposite with selenium vacancies was synthesized via a hydrothermal/annealing approach.During the annealing step,calcination under a H_(2)/Ar atmosphere facilitated the evaporation of selenium,thereby generating selenium vacancies.This study confirmed that RuSe_(1.6)-500 prepared by this method functions as an efficient electrocatalyst for the hydrogen evolution reaction(HER)in seawater.Furthermore,experiments and density functional theory calculations demonstrated that the enhanced electrocatalytic performance and resistance to Cl-induced corrosion in seawater can be attributed to the surface reconstruction of RuSe_(1.6)-500 during the HER process.Specifically,the reconstruction involves the adsorption of hydroxyl groups at selenium vacancies,leading to the formation of a hydroxy-rich surface on RuSe_(1.6)-500.The hydroxy-rich surface is responsible for the superior electrocatalytic activity and stability of RuSe_(1.6)-500 as an electrocatalyst for the HER in seawater.展开更多
The construction of complex stratigraphic surfaces is widely employed in many fields, such as petroleum exploration, geological modeling, and geological structure analysis. It also serves as an important foundation fo...The construction of complex stratigraphic surfaces is widely employed in many fields, such as petroleum exploration, geological modeling, and geological structure analysis. It also serves as an important foundation for data visualization and visual analysis in these fields. The existing surface construction methods have several deficiencies and face various difficulties, such as the presence of multitype faults and roughness of resulting surfaces. In this paper, a surface modeling method that uses geometric partial differential equations （PDEs） is introduced for the construction of stratigraphic surfaces. It effectively solves the problem of surface roughness caused by the irregularity of stratigraphic data distribution. To cope with the presence of multitype complex faults, a two-way projection algorithm between three- dimensional space and a two-dimensional plane is proposed. Using this algorithm, a unified method based on geometric PDEs is developed for dealing with multitype faults. Moreover, the corresponding geometric PDE is derived, and an algorithm based on an evolutionary solution is developed. The algorithm proposed for constructing spatial surfaces with real data verifies its computational efficiency and its ability to handle irregular data distribution. In particular, it can reconstruct faulty surfaces, especially those with overthrust faults.展开更多
Amorphous transition metal compounds(a-TMC)become one of the most promising pre-catalysts toward oxygen evolution reaction(OER)due to their high-entropy nature and flexible self-reconstruction to highly active derivat...Amorphous transition metal compounds(a-TMC)become one of the most promising pre-catalysts toward oxygen evolution reaction(OER)due to their high-entropy nature and flexible self-reconstruction to highly active derivatives.However,the loosen bonds inside the amorphous structure make it an electronic insulator with unstable structure.Here,monodispersed Ni^(2+)-phytate nanospheres implanted by Fe^(3+)ions(NS_(FeNiPA))were firstly prepared and subsequently transferred into homogeneous high-entropy type Fe-Ni-P-O-C amorphous nanospheres(CNS_(FeNiPO)).It is shown that the CNS_(FeNiPO) presents robust structure and remarkable Fe ions migration during potential-driven activation process,which benefits efficient surface reconstruction and spherical morphology preservation.The CNS_(FeNiPO) with low mass loading of 0.1mg/cm^(2)could deliver small overpotential of 270mV at 10mAcm^(−2)and almost 100%retention of the initial current density after 10h test.The improved electrocatalytic activity is attributed to the boosted electron transfer from Ni sites to O-containing intermediates by introduction of Fe and P atoms.Moreover,rechargeable Zn-air battery with CNS_(FeNiPO)+Pt/C could achieve lower charge potential platform and better cycling performance than that with commercial RuO_(2)+Pt/C.This work provides new insights into the design and understanding of high-entropy amorphous pre-catalysts toward OER.展开更多
Iron-based superconductors(FeSCs)feature a complex phase diagram,and their diverse cleavage terminations offer a versatile platform for modulating surface electronic states and investigating the underlying superconduc...Iron-based superconductors(FeSCs)feature a complex phase diagram,and their diverse cleavage terminations offer a versatile platform for modulating surface electronic states and investigating the underlying superconducting mechanisms.In this study,we explore the surface modulation of KCa_(2)Fe_(4)As_(4)F_(2)using scanning tunneling microscopy/spectroscopy.Cryogenically cleaved surfaces reveal multiple configurations,including√2×√2 reconstruction,1×2 and 1×3 stripes,as well as nanoscale vacancies.Reducing potassium coverage induces hole doping,which shifts the density of states peak toward the Fermi level and suppresses the superconducting gap from 4.8 meV to 3.2 meV.This behavior is reminiscent of the Van Hove singularity observed in hole-doped 122-type FeSCs.The band structure does not undergo a simple rigid shift,and the evolution of superconductivity can be attributed to the interplay between surface carriers and electronic correlations.Additionally,a V-shaped gap is observed at a unique location preserving the FeAs bilayer structure,where interlayer coupling effects are likely involved.The diversity of surface structures and electronic states in K12442 enhances our understanding of FeSCs and facilitates the modulation and application of FeAs superconducting layers.展开更多
The surface reconstruction behavior of transition metal phosphides precursors is considered as an important method to prepare efficient oxygen evolution catalysts,but there are still significant challenges in guiding ...The surface reconstruction behavior of transition metal phosphides precursors is considered as an important method to prepare efficient oxygen evolution catalysts,but there are still significant challenges in guiding catalyst design at the atomic scale.Here,the CoP nanowire with excellent water splitting performance and stability is used as a catalytic model to study the reconstruction process.Obvious double redox signals and valence evolution behavior of the Co site are observed,corresponding to Co^(2+)/Co^(3+)and Co^(3+)/Co4+caused by auto-oxidation process.Importantly,the in situ Raman spectrum exhibits the vibration signal of Co-OH in the non-Faradaic potential interval for oxygen evolution reaction,which is considered the initial step in reconstruction process.Density functional theory and ab initio molecular dynamics are used to elucidate this process at the atomic scale:First,OH^(-)exhibits a lower adsorption energy barrier and proton desorption energy barrier at the configuration surface,which proposes the formation of a single oxygen(-O)group.Under a higher-O group coverage,the Co-P bond is destroyed along with the POx groups.Subsequently,lower P vacancy formation energy confirm that the Ni-CoP configuration can fast transform into a highly active phase.Based on the optimized reconstruction behavior and rate-limiting barrier,the Ni-CoP nanowire exhibit an excellent overpotential of 1.59 V at 10 mA cm^(-2) for overall water splitting,which demonstrates low degradation(2.62%)during the 100 mA cm^(-2) for 100 h.This work provide systematic insights into the atomic-level reconstruction mechanism of transition metal phosphides,which benefit further design of water splitting catalysts.展开更多
Constructing heterostructures and facilitating surface reconstruction are effective ways to obtain excellent catalysts for the oxygen evolution reaction(OER).Surface reconstruction is a dynamic process that is affecte...Constructing heterostructures and facilitating surface reconstruction are effective ways to obtain excellent catalysts for the oxygen evolution reaction(OER).Surface reconstruction is a dynamic process that is affected by the built-in electric field of the heterostructure.In this study,P/N co-doped carbon-coated NiCo/Ni-CoO heterostructure was prepared by in situ acid etching,aniline polymerization,and pyrolysis.This method can form a tightly connected heterogeneous interface.It was found that introducing P-O bonds in the carbon shell can increase its work function,thereby enhancing the built-in electric field between the carbon shell and the core catalyst.Detailed characterizations confirm that the P-O bridge at the heterogeneous interface can provide an electron flow highway from the core to the shell.The generated carbon defects generated by P leaching during surface reconstruction also have strong electronabsorbing capacity.These effects promote the conversion of Co^(2+)to Co^(3+),thereby providing more highly active sites.The resulting catalyst shows significantly enhanced activity and stability.This study demonstrates the promoting effect of the built-in electric field on the surface reconstruction of the catalyst and emphasizes the importance of the construction of tightly connected heterogeneous interface,which is instructive for the design of excellent OER catalysts.展开更多
Transition metal selenides(TMSs)are effective pre-electrocatalysts and are commonly used in electrochemical processes.During the electrocatalytic oxygen evolution reaction(OER),metal cations in TMSs are in-situ recons...Transition metal selenides(TMSs)are effective pre-electrocatalysts and are commonly used in electrochemical processes.During the electrocatalytic oxygen evolution reaction(OER),metal cations in TMSs are in-situ reconstructed and converted into high-valence metal oxyhydroxides.However,a limited understanding of the effects of electro-oxidation and anion leaching has resulted in insufficient theoretical guidance for the rational design of efficient catalysts.Herein,FeSe@NiSe nanorods were fabricated for the OER using a facile hydrothermal selenization method supported on FeNi foam.In-situ Raman spectroscopy and multiple characterization techniques were employed to elucidate the mechanism of FeSe@NiSe surface evolution.Metal cations on the catalyst surface were reconstructed and converted into OER-active species Fe/NiOOH at low potential.As the applied potential increased,electro-oxidation and leaching of Se occurred,resulting in SeO_(4)^(2−)adsorption on the catalyst surface,which further enhanced catalytic activity.As a result,the reconstructed FeSe@NiSe/iron-nickel foam(INF)exhibited exceptional catalytic activity for OER,achieving an ultralow overpotential of 283 mV at a current density of 100 mA·cm^(−2).Notably,the bifunctional FeSe@NiSe/INF electrode facilitated overall water splitting,affording a current density of 10 mA·cm^(−2) only at 1.53 V,even superior to the noble RuO_(2)(+)||Pt/C(−).This work offers valuable insights into the surface evolution and electrocatalytic mechanisms of TMSs.展开更多
Substituting the sluggish oxygen evolution reaction with a more thermodynamically favorable ethanol oxidation reaction(EOR)offers an opportunity to circumvent the efficiency loss in water splitting and metal-air batte...Substituting the sluggish oxygen evolution reaction with a more thermodynamically favorable ethanol oxidation reaction(EOR)offers an opportunity to circumvent the efficiency loss in water splitting and metal-air batteries.However,the effect of the dynamic surface evolution of the catalyst in operating conditions on the activity of EOR lacks comprehensive understanding.Herein,we demonstrate a tunable operational catalyst activity through the modulated redox property of nickel oxalate(NCO)by establishing a relation between the oxidation behavior of Ni,surface reconstruction,and catalyst activity.We propose a repeated chemical-electrochemical reaction mechanism of EOR on NCO,which is rigorously investigated through a combination of operando Raman and nuclear magnetic resonance.The modulation of the oxidation trend of Ni by doping heteroatoms stimulates the electrochemical oxidation of the catalyst surface to NiOOH,which alters the catalyst activity for EOR.Assembled ethanol-assisted water electrolysis cell exhibits a reduced operating voltage for hydrogen production by 200 mV with a~100% Faradaic efficiency,and zinc-ethanol-air battery showed a 287 mV decreased charge-discharge voltage window and enhanced stability for over 500 h.展开更多
The rapid expansion of the automotive sector has significantly increased the demand for highperformance lithium-ion batteries,positioning Ni-rich layered cathodes as a promising solution due to their high energy densi...The rapid expansion of the automotive sector has significantly increased the demand for highperformance lithium-ion batteries,positioning Ni-rich layered cathodes as a promising solution due to their high energy density and cost-efficiency.However,these cathodes face critical challenges,including thermal instability and structural degradation at an elevated temperature,which hinder their practical application.This study introduces an advanced surface reconstruction strategy combining a LiScF_(4)coating,Sc/F surface co-doping,and a cation-mixing layer to address these issues.The LiScF_(4)coating serves as a durable protective barrier,reducing electrolyte decomposition,minimizing transition metal dissolution,and enhancing lithium-ion transport.Sc/F surface co-doping stabilizes lattice oxygen by increasing the energy barrier for oxygen vacancy formation and minimizing oxygen release,thereby suppressing phase transitions and interfacial side reactions.Additionally,the cation-mixing layer improves interfacial stability by alleviating lattice strain and supporting reversible cation migration,ensuring prolonged durability during cycling and under high-temperature conditions.These integrated modifications work synergistically to mitigate various degradation mechanisms,significantly improving the thermal stability,structural integrity,and electrochemical performance of Ni-rich cathodes.This approach offers a viable pathway for incorporating Ni-rich cathodes into advanced lithium-ion batteries,making them well-suited for applications requiring high thermal stability.Moreover,this research provides valuable guidance for the development of a multi-component modification strategy,paving the way for future innovations in energy storage materials and advancing high-performance battery technology.展开更多
Rationally regulating the inevitable dynamic evolution of the catalyst surface structure towards high efficiency for water electrolysis remains a significant challenge.Here,the ternary cobalt-iron-chromium double hydr...Rationally regulating the inevitable dynamic evolution of the catalyst surface structure towards high efficiency for water electrolysis remains a significant challenge.Here,the ternary cobalt-iron-chromium double hydroxide(DH)was synthesized on nickel foam as a monolithic catalytic electrode(CoFeCr-DH/NF)for the oxygen evolution reaction(OER)via a simple electrodeposition technique.The optimized Co_(0.7)Fe_(0.3)Cr-DH/NF electrode exhibited remarkable catalytic activity and stability.The overpotential at the current density of 100 mA cm^(-2) is only 281 mV,far exceeding those of other monolithic catalytic electrodes.Furthermore,we elucidated the variations in the valence states of metals during the OER process and found the electrochemical oxidation of Co^(2+)to Co^(3+)and leaching of Cr.Importantly,Cr-leaching can induce surface reconstruction,which not only optimizes the surface electronic structure to enhance the intrinsic activity but also increases the surface irregularity to enlarge the electrochemically active surface area,thereby significantly improving the OER performance.Theoretical calculations revealed that OER preferentially occurred at the adjacent Cr-leached Co sites and confirmed that the Cr-leached trimetallic CoFeCr-DH performs an outstanding OER performance.展开更多
Ni-based materials,widely recognized for their exceptional catalytic properties,experience structural transformations that profoundly influence their performance characteristics and operational stability.To deeply und...Ni-based materials,widely recognized for their exceptional catalytic properties,experience structural transformations that profoundly influence their performance characteristics and operational stability.To deeply understand the reconstruction mechanism of Ni-based catalysts,this review systematically summarizes the advanced strategies tailoring the dynamic reconstruction process,including electrochemical activation,defect engineering,partial etching,ionic doping,and heterostructure construction.Furthermore,we discuss the implications of these surface transformations on catalytic activity,highlighting their role in optimizing reaction pathways and enhancing overall efficiency in various electrooxidation reactions,such as oxygen evolution reaction(OER),urea oxidation reaction(UOR),glycerol oxidation reaction(GOR),hydroxymethylfurfural oxidation reaction(HMFOR),and ammonia oxidation reaction(AOR).By summarizing recent research findings,this review aims to provide a systematical summary of how surface dynamics can be harnessed to improve the design of Ni-based catalysts for a variety of electrooxidation applications,paving the way for advancements in energy conversion and storage technologies.展开更多
A new method for solving the tiling problem of surface reconstruction is proposed. The proposed method uses a snake algorithm to segment the original images, the contours are then transformed into strings by Freeman＇...A new method for solving the tiling problem of surface reconstruction is proposed. The proposed method uses a snake algorithm to segment the original images, the contours are then transformed into strings by Freeman＇ s code. Symbolic string matching technique is applied to establish a correspondence between the two consecutive contours. The surface is composed of the pieces reconstructed from the correspondence points. Experimental results show that the proposed method exhibits a good behavior for the quality of surface reconstruction and its time complexity is proportional to mn where m and n are the numbers of vertices of the two consecutive slices, respectively.展开更多
The large-scale application of water electrolysis for H_(2) production is hindered by the sluggish kinetics of the anodic oxygen evolution reaction(OER).To improve the efficiency of water electrolyzers,numerous effort...The large-scale application of water electrolysis for H_(2) production is hindered by the sluggish kinetics of the anodic oxygen evolution reaction(OER).To improve the efficiency of water electrolyzers,numerous efforts have been devoted to developing robust OER catalysts.Among them,Ni-based materials have been identified as state-of-the-art catalysts in alkaline conditions due to their high catalytic activity[1,2].During OER,these catalysts can undergo surface reconstruction and form(oxy)hydroxide species on the surface,which is the real active phase and its chemistry determines the OER performance[3].展开更多
Current research of binocular vision systems mainly need to resolve the camera’s intrinsic parameters before the reconstruction of three-dimensional(3D)objects.The classical Zhang’calibration is hardly to calculate ...Current research of binocular vision systems mainly need to resolve the camera’s intrinsic parameters before the reconstruction of three-dimensional(3D)objects.The classical Zhang’calibration is hardly to calculate all errors caused by perspective distortion and lens distortion.Also,the image-matching algorithm of the binocular vision system still needs to be improved to accelerate the reconstruction speed of welding pool surfaces.In this paper,a preset coordinate system was utilized for camera calibration instead of Zhang’calibration.The binocular vision system was modified to capture images of welding pool surfaces by suppressing the strong arc interference during gas metal arc welding.Combining and improving the algorithms of speeded up robust features,binary robust invariant scalable keypoints,and KAZE,the feature information of points(i.e.,RGB values,pixel coordinates)was extracted as the feature vector of the welding pool surface.Based on the characteristics of the welding images,a mismatch-elimination algorithm was developed to increase the accuracy of image-matching algorithms.The world coordinates of matching feature points were calculated to reconstruct the 3D shape of the welding pool surface.The effectiveness and accuracy of the reconstruction of welding pool surfaces were verified by experimental results.This research proposes the development of binocular vision algorithms that can reconstruct the surface of welding pools accurately to realize intelligent welding control systems in the future.展开更多
The fatigue performance of a workpiece depends on its surface quality.In traditional fatigue life prediction,the effect of surface quality is commonly accounted for by using empirical correction factors,which is impre...The fatigue performance of a workpiece depends on its surface quality.In traditional fatigue life prediction,the effect of surface quality is commonly accounted for by using empirical correction factors,which is imprecise when safety is of great concern.For surface quality,the surface topography is an important parameter,which introduces stress concentration that reduces the fatigue life.It is not feasible to test the stress concentration of different surface topographies.On the one hand,it is time-consuming and high-cost,and on the other hand,it cannot reflect the general statistical characteristics.With the help of surface reconstruction technology and interpolation method,a more efficient and economic approach is proposed,where FE simulation of workpiece with the reconstructed surface topography is used as a foundation for fatigue life prediction.The relationship between surface roughness(Sa)and fatigue life of the workpiece is studied with the proposed approach.展开更多
Rational reconstruction of oxygen evolution reaction(OER)precatalysts and performance index of OER catalysts are crucial but still challenging for universal water electrolysis.Herein,we develop a double-cation etching...Rational reconstruction of oxygen evolution reaction(OER)precatalysts and performance index of OER catalysts are crucial but still challenging for universal water electrolysis.Herein,we develop a double-cation etching strategy to tailor the electronic structure of NiMoO_(4),where the prepared NiMoO_(4) nanorods etched by H_(2)O_(2) reconstruct their surface with abundant cation deficiencies and lattice distortion.Calculation results reveal that the double cation deficiencies can make the upshift of d-band center for Ni atoms and the active sites with better oxygen adsorption capacity.As a result,the optimized sample(NMO-30M)possesses an overpotential of 260 mV at 10 mA cm−2 and excellent long-term durability of 162 h.Importantly,in situ Raman test reveals the rapid formation of high-oxidation-state transition metal hydroxide species,which can further help to improve the catalytic activity of NiMoO_(4) in OER.This work highlights the influence of surface remodification and shed some light on activating catalysts.展开更多
Taking AutoCAD2000 as platform, an algorithm for the reconstruction ofsurface from scattered data points based on VBA is presented. With this core technology customerscan be free from traditional AutoCAD as an electro...Taking AutoCAD2000 as platform, an algorithm for the reconstruction ofsurface from scattered data points based on VBA is presented. With this core technology customerscan be free from traditional AutoCAD as an electronic board and begin to create actual presentationof real-world objects. VBA is not only a very powerful tool of development, but with very simplesyntax. Associating with those solids, objects and commands of AutoCAD 2000, VBA notably simplifiesprevious complex algorithms, graphical presentations and processing, etc. Meanwhile, it can avoidappearance of complex data structure and data format in reverse design with other modeling software.Applying VBA to reverse engineering can greatly improve modeling efficiency and facilitate surfacereconstruction.展开更多
In order to determine the structures of Si（111）-√7 √3-In surfaces and to understand their electronic properties, we construct six models of both hexagonal and rectangular types and perform first-principles calcula...In order to determine the structures of Si（111）-√7 √3-In surfaces and to understand their electronic properties, we construct six models of both hexagonal and rectangular types and perform first-principles calculations. Their scanning tunneling microscopic images and work functions are simulated and compared with experimental results. In this way, the hex-H3＇ and rect-T1 models are identified as the experimental configurations for the hexagonal and rectangular types, respectively. The structural evolution mechanism of the In/Si（lll） surface with indium coverage around 1.0 monolayer is discussed. The 4×1 and -√7× √3 phases are suggested to have two different types of evolution mechanisms, consistent with experimental results.展开更多
基金Funded by the National Natural Science Foundation of China(No.51402097)the National Science Foundation of Hubei Province(No.2014CFB597)the State Key Laboratory of Advanced Technology for Material Synthesis and Processing(Wuhan University of Technology)(No.2017-KF-11)
文摘The surface reconstructing of vermicular alpha-alumina exposed under electron-beam irradiation was investigated by a scanning electron microscope with 0.5 keV beam energy and by a transmittance electron microscope at room temperature and 90 K, respectively. The in-situ recorded results showed that the present electron-beam-induced surface reconstructing was both electron dose and temperature dependent and accompanied by bulk shape change. The surface reconstruction was explained by an Auger decay process, in which surface composition constancy was proposed by the equilibrium between electron stmulated reduction of Al2O3 and oxidation of aluminum by desorbed oxygen from bulk.
基金supported by the National Natural Science Foundation of China(Grant No.52402430,52572380)the Natural Science Foundation of Shanghai(Grant No.23ZR1466300).
文摘Runway surface roughness significantly influences aircraft vibrations during takeoff and landing,affecting both flight safety and pavement durability.Aircraft operate at high speeds and wide gear spans,making them sensitive to long-wavelength(15–120 m)and lateral irregularities,which are often overlooked in traditional roughness models.This study aims to construct a three-dimensional runway roughness modeling framework integrating"precise detection-spectrum analysis-spatial reconstruction"in response to this issue.Combining the elevation data of 37 runways(5 asphalt runways and 32 cement runways)measured by a vehicle-mounted laser profilometer and the BeiDou positioning system,the power spectrum analysis was carried out by the Burg method and the spectrum models of asphalt and cement runways were fitted respectively.Meanwhile,a new exponential lateral coherence function was proposed.Finally,the three-dimensional spatial model was reconstructed by using the transfer function and genetic algorithm.The results show that the error of the measured elevation data is less than 1 cm.The spectral characteristics of different pavement types are significantly different.Among them,the R^(2) of the asphalt runway fitted with the Sussman model is greater than 0.9.The cement runway needs to be characterized by a piecewise function to represent the spectral mutation.The fitting error of the new index's lateral coherence function has been reduced to 0.012.The reconstructed three-dimensional model is in good agreement with the theoretical value and the error does not exceed 0.18 mm^(2) m/c.Finally,a three-dimensional model of 0–20 m in the lateral direction and 3000 m in the longitudinal direction is generated,providing support for aircraft vibration simulation and pavement maintenance.
基金supported by the National Key Research and Development Program of China(2022YFB3805600,2022YFB3805604)the National Natural Science Foundation of China(52201286)+3 种基金the National 111 Project(B20002)the Key R&D Program of Shandong Province,China(2023CXGC010314)the Hubei Provincial Natural Science Foundation of China(2024AFB195)the Fundamental Research Funds for the Central Universities(104972025KFYzxk0014,104972024KFYjlb0008)。
文摘The rationally designed ruthenium selenide(RuSe_(1.6)-500)nanocomposite with selenium vacancies was synthesized via a hydrothermal/annealing approach.During the annealing step,calcination under a H_(2)/Ar atmosphere facilitated the evaporation of selenium,thereby generating selenium vacancies.This study confirmed that RuSe_(1.6)-500 prepared by this method functions as an efficient electrocatalyst for the hydrogen evolution reaction(HER)in seawater.Furthermore,experiments and density functional theory calculations demonstrated that the enhanced electrocatalytic performance and resistance to Cl-induced corrosion in seawater can be attributed to the surface reconstruction of RuSe_(1.6)-500 during the HER process.Specifically,the reconstruction involves the adsorption of hydroxyl groups at selenium vacancies,leading to the formation of a hydroxy-rich surface on RuSe_(1.6)-500.The hydroxy-rich surface is responsible for the superior electrocatalytic activity and stability of RuSe_(1.6)-500 as an electrocatalyst for the HER in seawater.
基金financially supported by the National Natural Science foundation of China(No.U1562218)
文摘The construction of complex stratigraphic surfaces is widely employed in many fields, such as petroleum exploration, geological modeling, and geological structure analysis. It also serves as an important foundation for data visualization and visual analysis in these fields. The existing surface construction methods have several deficiencies and face various difficulties, such as the presence of multitype faults and roughness of resulting surfaces. In this paper, a surface modeling method that uses geometric partial differential equations （PDEs） is introduced for the construction of stratigraphic surfaces. It effectively solves the problem of surface roughness caused by the irregularity of stratigraphic data distribution. To cope with the presence of multitype complex faults, a two-way projection algorithm between three- dimensional space and a two-dimensional plane is proposed. Using this algorithm, a unified method based on geometric PDEs is developed for dealing with multitype faults. Moreover, the corresponding geometric PDE is derived, and an algorithm based on an evolutionary solution is developed. The algorithm proposed for constructing spatial surfaces with real data verifies its computational efficiency and its ability to handle irregular data distribution. In particular, it can reconstruct faulty surfaces, especially those with overthrust faults.
基金financially supported by National Natural Science Foundation of China(22278170,52172058)Natural Science Foundation of Anhui Province(2408085QB037)+3 种基金Natural Science Foundation of Anhui Provincial Department of Education(2023AH020042,2024AH051721)financial support from High-Level Talents Introduction and Cultivation Plan of Anhui Province-Young Top Talent,Huainan Innovation and Entrepreneurship Star Team(HNSTD-2024),Huainan Research Center of New Carbon Energy Materials(HNSPT02)New Energy Materials and Technology Research Center of Huainan Normal University.Business Finland,BATCircle2.0 project(Grant No.44612/31/2020)is acknowledged for financial supportU.L.acknowledges Finnish Research Impact Foundation for Tandem Industry Academy Professorship funding in 2023-2025.
文摘Amorphous transition metal compounds(a-TMC)become one of the most promising pre-catalysts toward oxygen evolution reaction(OER)due to their high-entropy nature and flexible self-reconstruction to highly active derivatives.However,the loosen bonds inside the amorphous structure make it an electronic insulator with unstable structure.Here,monodispersed Ni^(2+)-phytate nanospheres implanted by Fe^(3+)ions(NS_(FeNiPA))were firstly prepared and subsequently transferred into homogeneous high-entropy type Fe-Ni-P-O-C amorphous nanospheres(CNS_(FeNiPO)).It is shown that the CNS_(FeNiPO) presents robust structure and remarkable Fe ions migration during potential-driven activation process,which benefits efficient surface reconstruction and spherical morphology preservation.The CNS_(FeNiPO) with low mass loading of 0.1mg/cm^(2)could deliver small overpotential of 270mV at 10mAcm^(−2)and almost 100%retention of the initial current density after 10h test.The improved electrocatalytic activity is attributed to the boosted electron transfer from Ni sites to O-containing intermediates by introduction of Fe and P atoms.Moreover,rechargeable Zn-air battery with CNS_(FeNiPO)+Pt/C could achieve lower charge potential platform and better cycling performance than that with commercial RuO_(2)+Pt/C.This work provides new insights into the design and understanding of high-entropy amorphous pre-catalysts toward OER.
基金supported by the National Key Research and Development Program of China(Grant Nos.2024YFA1611103 and 2022YFA1403203)the Innovation Program for Quantum Science and Technology(Grant Nos.2024ZD0301300 and 2021ZD0302802)the National Natural Science Foundation of China(Grant Nos.12474128,12374133,12204008,and 12104004)。
文摘Iron-based superconductors(FeSCs)feature a complex phase diagram,and their diverse cleavage terminations offer a versatile platform for modulating surface electronic states and investigating the underlying superconducting mechanisms.In this study,we explore the surface modulation of KCa_(2)Fe_(4)As_(4)F_(2)using scanning tunneling microscopy/spectroscopy.Cryogenically cleaved surfaces reveal multiple configurations,including√2×√2 reconstruction,1×2 and 1×3 stripes,as well as nanoscale vacancies.Reducing potassium coverage induces hole doping,which shifts the density of states peak toward the Fermi level and suppresses the superconducting gap from 4.8 meV to 3.2 meV.This behavior is reminiscent of the Van Hove singularity observed in hole-doped 122-type FeSCs.The band structure does not undergo a simple rigid shift,and the evolution of superconductivity can be attributed to the interplay between surface carriers and electronic correlations.Additionally,a V-shaped gap is observed at a unique location preserving the FeAs bilayer structure,where interlayer coupling effects are likely involved.The diversity of surface structures and electronic states in K12442 enhances our understanding of FeSCs and facilitates the modulation and application of FeAs superconducting layers.
基金the National Natural Science Foundation of China(12025503,U23B2072,12105208)the Fundamental Research Funds for the Center Universities(2042024kf0001)。
文摘The surface reconstruction behavior of transition metal phosphides precursors is considered as an important method to prepare efficient oxygen evolution catalysts,but there are still significant challenges in guiding catalyst design at the atomic scale.Here,the CoP nanowire with excellent water splitting performance and stability is used as a catalytic model to study the reconstruction process.Obvious double redox signals and valence evolution behavior of the Co site are observed,corresponding to Co^(2+)/Co^(3+)and Co^(3+)/Co4+caused by auto-oxidation process.Importantly,the in situ Raman spectrum exhibits the vibration signal of Co-OH in the non-Faradaic potential interval for oxygen evolution reaction,which is considered the initial step in reconstruction process.Density functional theory and ab initio molecular dynamics are used to elucidate this process at the atomic scale:First,OH^(-)exhibits a lower adsorption energy barrier and proton desorption energy barrier at the configuration surface,which proposes the formation of a single oxygen(-O)group.Under a higher-O group coverage,the Co-P bond is destroyed along with the POx groups.Subsequently,lower P vacancy formation energy confirm that the Ni-CoP configuration can fast transform into a highly active phase.Based on the optimized reconstruction behavior and rate-limiting barrier,the Ni-CoP nanowire exhibit an excellent overpotential of 1.59 V at 10 mA cm^(-2) for overall water splitting,which demonstrates low degradation(2.62%)during the 100 mA cm^(-2) for 100 h.This work provide systematic insights into the atomic-level reconstruction mechanism of transition metal phosphides,which benefit further design of water splitting catalysts.
基金financially supported by the National Natural Science Foundation of China(Grant No.52073106)。
文摘Constructing heterostructures and facilitating surface reconstruction are effective ways to obtain excellent catalysts for the oxygen evolution reaction(OER).Surface reconstruction is a dynamic process that is affected by the built-in electric field of the heterostructure.In this study,P/N co-doped carbon-coated NiCo/Ni-CoO heterostructure was prepared by in situ acid etching,aniline polymerization,and pyrolysis.This method can form a tightly connected heterogeneous interface.It was found that introducing P-O bonds in the carbon shell can increase its work function,thereby enhancing the built-in electric field between the carbon shell and the core catalyst.Detailed characterizations confirm that the P-O bridge at the heterogeneous interface can provide an electron flow highway from the core to the shell.The generated carbon defects generated by P leaching during surface reconstruction also have strong electronabsorbing capacity.These effects promote the conversion of Co^(2+)to Co^(3+),thereby providing more highly active sites.The resulting catalyst shows significantly enhanced activity and stability.This study demonstrates the promoting effect of the built-in electric field on the surface reconstruction of the catalyst and emphasizes the importance of the construction of tightly connected heterogeneous interface,which is instructive for the design of excellent OER catalysts.
基金supported by the National Natural Science Foundation of China(No.22469018)the Natural Science Basic Research Program of Department of Science and Technology of Shaanxi Province(Nos.2023-JC-ZD-22 and 2023-JC-YB-404)the Scientific Research Startup Program for Introduced Talents of Shaanxi University of Technology(Nos.SLGRCQD2303 and SLGRCQD2306).
文摘Transition metal selenides(TMSs)are effective pre-electrocatalysts and are commonly used in electrochemical processes.During the electrocatalytic oxygen evolution reaction(OER),metal cations in TMSs are in-situ reconstructed and converted into high-valence metal oxyhydroxides.However,a limited understanding of the effects of electro-oxidation and anion leaching has resulted in insufficient theoretical guidance for the rational design of efficient catalysts.Herein,FeSe@NiSe nanorods were fabricated for the OER using a facile hydrothermal selenization method supported on FeNi foam.In-situ Raman spectroscopy and multiple characterization techniques were employed to elucidate the mechanism of FeSe@NiSe surface evolution.Metal cations on the catalyst surface were reconstructed and converted into OER-active species Fe/NiOOH at low potential.As the applied potential increased,electro-oxidation and leaching of Se occurred,resulting in SeO_(4)^(2−)adsorption on the catalyst surface,which further enhanced catalytic activity.As a result,the reconstructed FeSe@NiSe/iron-nickel foam(INF)exhibited exceptional catalytic activity for OER,achieving an ultralow overpotential of 283 mV at a current density of 100 mA·cm^(−2).Notably,the bifunctional FeSe@NiSe/INF electrode facilitated overall water splitting,affording a current density of 10 mA·cm^(−2) only at 1.53 V,even superior to the noble RuO_(2)(+)||Pt/C(−).This work offers valuable insights into the surface evolution and electrocatalytic mechanisms of TMSs.
基金supported by the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT(NRF-2022M3H4A1A04076616 and NRF-2022M3H4A1A01008918)a cooperation project of“Basic project(referring to projects performed with the budget directly contributed by the Government to achieve the purposes of establishment of Government–funded research Institutes)”supported by the Korea Research Institute of Chemical Technology(KRICT).
文摘Substituting the sluggish oxygen evolution reaction with a more thermodynamically favorable ethanol oxidation reaction(EOR)offers an opportunity to circumvent the efficiency loss in water splitting and metal-air batteries.However,the effect of the dynamic surface evolution of the catalyst in operating conditions on the activity of EOR lacks comprehensive understanding.Herein,we demonstrate a tunable operational catalyst activity through the modulated redox property of nickel oxalate(NCO)by establishing a relation between the oxidation behavior of Ni,surface reconstruction,and catalyst activity.We propose a repeated chemical-electrochemical reaction mechanism of EOR on NCO,which is rigorously investigated through a combination of operando Raman and nuclear magnetic resonance.The modulation of the oxidation trend of Ni by doping heteroatoms stimulates the electrochemical oxidation of the catalyst surface to NiOOH,which alters the catalyst activity for EOR.Assembled ethanol-assisted water electrolysis cell exhibits a reduced operating voltage for hydrogen production by 200 mV with a~100% Faradaic efficiency,and zinc-ethanol-air battery showed a 287 mV decreased charge-discharge voltage window and enhanced stability for over 500 h.
基金supported by the National Natural Science Foundation of China(22179008)support from the Beijing Nova Program(20230484241)+1 种基金support from the China Postdoctoral Science Foundation(2024M754084)the Postdoctoral Fellowship Program of CPSF(GZB20230931)。
文摘The rapid expansion of the automotive sector has significantly increased the demand for highperformance lithium-ion batteries,positioning Ni-rich layered cathodes as a promising solution due to their high energy density and cost-efficiency.However,these cathodes face critical challenges,including thermal instability and structural degradation at an elevated temperature,which hinder their practical application.This study introduces an advanced surface reconstruction strategy combining a LiScF_(4)coating,Sc/F surface co-doping,and a cation-mixing layer to address these issues.The LiScF_(4)coating serves as a durable protective barrier,reducing electrolyte decomposition,minimizing transition metal dissolution,and enhancing lithium-ion transport.Sc/F surface co-doping stabilizes lattice oxygen by increasing the energy barrier for oxygen vacancy formation and minimizing oxygen release,thereby suppressing phase transitions and interfacial side reactions.Additionally,the cation-mixing layer improves interfacial stability by alleviating lattice strain and supporting reversible cation migration,ensuring prolonged durability during cycling and under high-temperature conditions.These integrated modifications work synergistically to mitigate various degradation mechanisms,significantly improving the thermal stability,structural integrity,and electrochemical performance of Ni-rich cathodes.This approach offers a viable pathway for incorporating Ni-rich cathodes into advanced lithium-ion batteries,making them well-suited for applications requiring high thermal stability.Moreover,this research provides valuable guidance for the development of a multi-component modification strategy,paving the way for future innovations in energy storage materials and advancing high-performance battery technology.
基金financially supported by the National Natural Science Foundation of China(Nos.22162026 and 22263011)the Shaanxi Provincial Science and Technology Plan Project(No.2020JQ-792)+2 种基金the Youth Science and Technology Star Project of Shaanxi Province(No.2023KJXX-053)the Science and Technology Plan Project of Yulin Government(Nos.CXY-2022-82,CXY-2022-186,and 2023-CXY-213)the Training Program of Innovation and Entrepreneurship for Undergraduates(No.S202310719113).
文摘Rationally regulating the inevitable dynamic evolution of the catalyst surface structure towards high efficiency for water electrolysis remains a significant challenge.Here,the ternary cobalt-iron-chromium double hydroxide(DH)was synthesized on nickel foam as a monolithic catalytic electrode(CoFeCr-DH/NF)for the oxygen evolution reaction(OER)via a simple electrodeposition technique.The optimized Co_(0.7)Fe_(0.3)Cr-DH/NF electrode exhibited remarkable catalytic activity and stability.The overpotential at the current density of 100 mA cm^(-2) is only 281 mV,far exceeding those of other monolithic catalytic electrodes.Furthermore,we elucidated the variations in the valence states of metals during the OER process and found the electrochemical oxidation of Co^(2+)to Co^(3+)and leaching of Cr.Importantly,Cr-leaching can induce surface reconstruction,which not only optimizes the surface electronic structure to enhance the intrinsic activity but also increases the surface irregularity to enlarge the electrochemically active surface area,thereby significantly improving the OER performance.Theoretical calculations revealed that OER preferentially occurred at the adjacent Cr-leached Co sites and confirmed that the Cr-leached trimetallic CoFeCr-DH performs an outstanding OER performance.
基金supported by National Natural Science Foundation of China(Nos.52073199 and 52274304)。
文摘Ni-based materials,widely recognized for their exceptional catalytic properties,experience structural transformations that profoundly influence their performance characteristics and operational stability.To deeply understand the reconstruction mechanism of Ni-based catalysts,this review systematically summarizes the advanced strategies tailoring the dynamic reconstruction process,including electrochemical activation,defect engineering,partial etching,ionic doping,and heterostructure construction.Furthermore,we discuss the implications of these surface transformations on catalytic activity,highlighting their role in optimizing reaction pathways and enhancing overall efficiency in various electrooxidation reactions,such as oxygen evolution reaction(OER),urea oxidation reaction(UOR),glycerol oxidation reaction(GOR),hydroxymethylfurfural oxidation reaction(HMFOR),and ammonia oxidation reaction(AOR).By summarizing recent research findings,this review aims to provide a systematical summary of how surface dynamics can be harnessed to improve the design of Ni-based catalysts for a variety of electrooxidation applications,paving the way for advancements in energy conversion and storage technologies.
文摘A new method for solving the tiling problem of surface reconstruction is proposed. The proposed method uses a snake algorithm to segment the original images, the contours are then transformed into strings by Freeman＇ s code. Symbolic string matching technique is applied to establish a correspondence between the two consecutive contours. The surface is composed of the pieces reconstructed from the correspondence points. Experimental results show that the proposed method exhibits a good behavior for the quality of surface reconstruction and its time complexity is proportional to mn where m and n are the numbers of vertices of the two consecutive slices, respectively.
文摘The large-scale application of water electrolysis for H_(2) production is hindered by the sluggish kinetics of the anodic oxygen evolution reaction(OER).To improve the efficiency of water electrolyzers,numerous efforts have been devoted to developing robust OER catalysts.Among them,Ni-based materials have been identified as state-of-the-art catalysts in alkaline conditions due to their high catalytic activity[1,2].During OER,these catalysts can undergo surface reconstruction and form(oxy)hydroxide species on the surface,which is the real active phase and its chemistry determines the OER performance[3].
基金Supported by National Natural Science Foundation of China(Grant No.51775313)Major Program of Shandong Province Natural Science Foundation(Grant No.ZR2018ZC1760)Young Scholars Program of Shandong University(Grant No.2017WLJH24).
文摘Current research of binocular vision systems mainly need to resolve the camera’s intrinsic parameters before the reconstruction of three-dimensional(3D)objects.The classical Zhang’calibration is hardly to calculate all errors caused by perspective distortion and lens distortion.Also,the image-matching algorithm of the binocular vision system still needs to be improved to accelerate the reconstruction speed of welding pool surfaces.In this paper,a preset coordinate system was utilized for camera calibration instead of Zhang’calibration.The binocular vision system was modified to capture images of welding pool surfaces by suppressing the strong arc interference during gas metal arc welding.Combining and improving the algorithms of speeded up robust features,binary robust invariant scalable keypoints,and KAZE,the feature information of points(i.e.,RGB values,pixel coordinates)was extracted as the feature vector of the welding pool surface.Based on the characteristics of the welding images,a mismatch-elimination algorithm was developed to increase the accuracy of image-matching algorithms.The world coordinates of matching feature points were calculated to reconstruct the 3D shape of the welding pool surface.The effectiveness and accuracy of the reconstruction of welding pool surfaces were verified by experimental results.This research proposes the development of binocular vision algorithms that can reconstruct the surface of welding pools accurately to realize intelligent welding control systems in the future.
基金Projects(51535012,U1604255)supported by the National Natural Science Foundation of ChinaProject(2016JC2001)supported by the Key Research and Development Project of Hunan Province,China
文摘The fatigue performance of a workpiece depends on its surface quality.In traditional fatigue life prediction,the effect of surface quality is commonly accounted for by using empirical correction factors,which is imprecise when safety is of great concern.For surface quality,the surface topography is an important parameter,which introduces stress concentration that reduces the fatigue life.It is not feasible to test the stress concentration of different surface topographies.On the one hand,it is time-consuming and high-cost,and on the other hand,it cannot reflect the general statistical characteristics.With the help of surface reconstruction technology and interpolation method,a more efficient and economic approach is proposed,where FE simulation of workpiece with the reconstructed surface topography is used as a foundation for fatigue life prediction.The relationship between surface roughness(Sa)and fatigue life of the workpiece is studied with the proposed approach.
基金supported by the National Natural Science Foundation of China(No.12004146)Natural Science Foundation of Gansu Province,China(Nos.20JR5RA303 and 20JR10RA648)the Fundamental Research Funds for the Central Universities(No.LZUMMM2022007).
文摘Rational reconstruction of oxygen evolution reaction(OER)precatalysts and performance index of OER catalysts are crucial but still challenging for universal water electrolysis.Herein,we develop a double-cation etching strategy to tailor the electronic structure of NiMoO_(4),where the prepared NiMoO_(4) nanorods etched by H_(2)O_(2) reconstruct their surface with abundant cation deficiencies and lattice distortion.Calculation results reveal that the double cation deficiencies can make the upshift of d-band center for Ni atoms and the active sites with better oxygen adsorption capacity.As a result,the optimized sample(NMO-30M)possesses an overpotential of 260 mV at 10 mA cm−2 and excellent long-term durability of 162 h.Importantly,in situ Raman test reveals the rapid formation of high-oxidation-state transition metal hydroxide species,which can further help to improve the catalytic activity of NiMoO_(4) in OER.This work highlights the influence of surface remodification and shed some light on activating catalysts.
文摘Taking AutoCAD2000 as platform, an algorithm for the reconstruction ofsurface from scattered data points based on VBA is presented. With this core technology customerscan be free from traditional AutoCAD as an electronic board and begin to create actual presentationof real-world objects. VBA is not only a very powerful tool of development, but with very simplesyntax. Associating with those solids, objects and commands of AutoCAD 2000, VBA notably simplifiesprevious complex algorithms, graphical presentations and processing, etc. Meanwhile, it can avoidappearance of complex data structure and data format in reverse design with other modeling software.Applying VBA to reverse engineering can greatly improve modeling efficiency and facilitate surfacereconstruction.
基金V. ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.20603032, No.20733004, No.21121003, No.91021004, No.20933006）, the National Key Basic Research Program （No.2011CB921400）, the Foundation of National Excellent Doctoral Dissertation of China （No.200736）, the Fundamental Research Funds for the Central Universities （No.WK2340000006 and No.WK2060140005）, and the Shanghai Supercompurer Center, the USTC-HP HPC Project, and the SCCAS.
文摘In order to determine the structures of Si（111）-√7 √3-In surfaces and to understand their electronic properties, we construct six models of both hexagonal and rectangular types and perform first-principles calculations. Their scanning tunneling microscopic images and work functions are simulated and compared with experimental results. In this way, the hex-H3＇ and rect-T1 models are identified as the experimental configurations for the hexagonal and rectangular types, respectively. The structural evolution mechanism of the In/Si（lll） surface with indium coverage around 1.0 monolayer is discussed. The 4×1 and -√7× √3 phases are suggested to have two different types of evolution mechanisms, consistent with experimental results.
