TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing Ti...TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing TiB_(2)coatings have disadvantages such as high equipment costs,complicated processes,and highly toxic gas emissions.This paper proposes an environmentally friendly method,which requires inexpensive equipment and simple processing,for preparing TiB_(2)coating on molybdenum via electrophoretic deposition within Na3AlF6-based molten salts.The produced TiB_(2)layer had an approximate thickness of 60μm and exhibited high density,outstanding hardness(38.2 GPa)and robust adhesion strength(51 N).Additionally,high-temperature oxidation experiments revealed that,at900℃,the TiB_(2)coating provided effective protection to the molybdenum substrate against oxidation for 3 h.This result indicates that the TiB_(2)coating prepared on molybdenum using molten salt electrophoretic deposition possesses good high-temperature oxidation resistance.展开更多
Laser directed energy deposition(LDED)is an emerging branch of metal-based additive manufacturing(AM)processes,offering unprecedented capabilities for high-performance fabrication with complex geometries and near-net ...Laser directed energy deposition(LDED)is an emerging branch of metal-based additive manufacturing(AM)processes,offering unprecedented capabilities for high-performance fabrication with complex geometries and near-net shapes.This technology is gathering increasing attention from industries such as biomedical,automotive,and aerospace.However,achieving consistent part quality and desired material properties is challenging due to intricate processing parameters and potential process defects such as dynamic melt-pool behavior and localized heat accumulation.This paper reviews recent advances in on-line quality control,focusing on in-situ measurement and closed-loop control for efficient assurance of LDED-fabricated parts.The quality principles,encompassing accuracy and material performance,are summarized to lay a foundation for understanding the mechanisms of quality defects and influencing factors.This review explores and thoroughly compares advancements in indirect process measurements,such as optical,thermal,and acoustic monitoring with direct quality measurements,including laser-line scanning and operando synchrotron X-ray imaging.Depending on the sensing techniques,this paper highlights a hierarchical control strategy for adaptive parameter regulation on intra-layer and inter-layer scales.The requirements and performance of various state-of-the-art controllers are critically compared to indicate their suitable applications.The importance of machine learning in detecting process anomalies and predicting build quality based on sensory signals is also outlined.Future directions are proposed towards adaptive,automated,and intelligent quality control,with a focus on multi-modal monitoring,physics-informed neural networks for interpretable analysis,and multi-objective control applications.展开更多
Rechargeable aqueous zinc-ion batteries(AZIBs)are widely studied for energy storage because of their high safety,low cost and high energy/power density.However,the practical application of AZIBs is limited by dendrite...Rechargeable aqueous zinc-ion batteries(AZIBs)are widely studied for energy storage because of their high safety,low cost and high energy/power density.However,the practical application of AZIBs is limited by dendrite formation at the zinc anode under high-depth deposition,which results in reduced cycle life and overall performance.Herein,we propose an effective and scalable stepwise deposition approach that integrates uniform nucleation and dense growth through the construction of ultrathin ZnO nanofiber arrays(ZONAs)on the zinc anode surface,along with the introduction of an anionic surfactant(AS)into the electrolyte.This approach yields a uniform,dense and dendrite-free Zn anode during cycling,maintaining stable cycling for 2100 h under a high deposition depth of 10 mAh cm^(-2)at an extremely high current density of 10 m A cm^(-2).Additionally,full cells using MnO_(2)cathodes exhibit stable cycling for 6000cycles at 5 A g^(-1),with a capacity retention of 75%.Furthermore,the pouch-type cell with an area of90 cm2delivers a capacity of 60 m Ah and maintains stable cycling for 540 cycles at 200 mA,highlighting its strong potential for scalability.展开更多
To study the characteristics of atmospheric dry and wet deposition in the upper reaches of Baiyangdian,two sampling sites in Baoding City were monitored for 1 year from September 2018 to August 2019.The results showed...To study the characteristics of atmospheric dry and wet deposition in the upper reaches of Baiyangdian,two sampling sites in Baoding City were monitored for 1 year from September 2018 to August 2019.The results showed that the dry and wet deposition fluxes of total nitrogen(TN)during the monitoring period were 6.87 and 6.46 kg/(hm^(2)·a),respectively.The ratio of wet to dry deposition of TN was approximately 1∶1,with wet deposition being dominated by ammonium nitrogen deposition.The dry and wet deposition fluxes of total phosphorus(TP)were 0.228 and 0.125 kg/(hm^(2)·a),and it was dominated by dry deposition.The average concentration of TN in wet deposition exceeded the standard threshold for eutrophic waters,and its ecological effects on the Baiyangdian basin should be concerned.Wet deposition fluxes of nitrogen and phosphorus had a significantly positive correlation with rainfall,while their deposition concentrations were negatively correlated with rainfall.The dry deposition of atmospheric nitrogen and phosphorus was influenced by the amount of dustfall and climatic factors such as rainfall,temperature,and humidity,which mainly occurred from April to August.展开更多
There is increasing interest in understanding atmospheric phosphorus(P)deposition and its impacts on plant pro-ductivity and carbon sinks in ecosystems.However,the global pattern of P deposition remains poorly underst...There is increasing interest in understanding atmospheric phosphorus(P)deposition and its impacts on plant pro-ductivity and carbon sinks in ecosystems.However,the global pattern of P deposition remains poorly understood,primarily due to the sparseness of data in Asia.In this study,the authors compiled 396 published observations of atmospheric P deposition from 1959 to 2020 on the global scale.The results gave a geometric mean bulk P deposition value of 0.32 kg ha−1 yr−1,or a global P budget of 4.4 Tg yr−1.Compared with the period 1959-2000,the authors found an elevated P deposition in Europe and Asia during 2001-2020,likely due to the increas-ing agricultural emissions and fossil fuel combustion-related sources in addition to dust emissions.The findings highlight the need to quantify the impacts of elevated P deposition from anthropogenic emissions on long-term ecosystem development in the context of carbon neutrality and clean-air actions.展开更多
Intrapancreatic fat deposition(IPFD)has garnered increasing attention in recent years.The prevalence of IPFD is relatively high and associated with factors such as obesity,age,and sex.However,the pathophysiological me...Intrapancreatic fat deposition(IPFD)has garnered increasing attention in recent years.The prevalence of IPFD is relatively high and associated with factors such as obesity,age,and sex.However,the pathophysiological mechanisms underlying IPFD remain unclear,with several potential contributing factors,including oxida-tive stress,alterations in the gut microbiota,and hormonal imbalances.IPFD was found to be highly correlated with the occurrence and prognosis of exocrine pan-creatic diseases.Although imaging techniques remain the primary diagnostic approach for IPFD,an expanding array of biomarkers and clinical scoring systems have been identified for screening purposes.Currently,effective treatments for IPFD are not available;however,existing medications,such as glucagon-like peptide-1 receptor agonists,and new therapeutic approaches explored in animal models have shown considerable potential for managing this disease.This paper reviews the pathogenesis of IPFD,its association with exocrine pancreatic disea-ses,and recent advancements in its diagnosis and treatment,emphasizing the significant clinical relevance of IPFD.展开更多
Aqueous zinc-ion electrochromic(EC)technology,boasting the capability to fulfill both safety and cost-ef⁃fectiveness requirements,is garnering extensive attention in various application areas including smart windows,t...Aqueous zinc-ion electrochromic(EC)technology,boasting the capability to fulfill both safety and cost-ef⁃fectiveness requirements,is garnering extensive attention in various application areas including smart windows,thermal management,displays,and camouflage.However,typical inorganic EC materials,such as tungsten oxides(WO_(3)),of⁃ten suffer from slow ion diffusion kinetics and limited optical contrast within the aqueous Zn^(2+)electrolyte because of the large size and strong Coulombic interactions of the Zn^(2+),which limits their wide applicability.Here,ordered WO_(3)nanowire films,constructed by a one-step grazing angle deposition method,is demonstrated to boost the response speed and optical contrast during EC phenomena.Compared with dense films,the ordered WO_(3)nanowire films with a porosity of 44.6%demonstrate anti-reflective property and excellent comprehensive EC performance,including fast response time(3.6 s and 1.2 s for coloring and bleaching,respectively),large optical contrast(66.6%at 700 nm)and high col⁃oration efficiency(64.3 cm^(2)·C^(-1)).A large-area prototype EC device(17 cm×12 cm)with fast color-switching is also successfully achieved.Mechanistic studies show that the improved performance is mainly due to the ordered porous nanowire structures,which provides direct electron transfer paths and sufficient interfacial contacts,thus simultaneously enhancing the electrochemical activity and fast redox kinetics.This study provides a simple and effective strategy to im⁃prove the performance of tungsten oxide-based aqueous zinc ion EC materials and devices.展开更多
The layer-by-layer deposition strategy of additive manufacturing makes it ideal to fabricate dissimilar alloy components with varying functionality,which has promising application potential in a large number of indust...The layer-by-layer deposition strategy of additive manufacturing makes it ideal to fabricate dissimilar alloy components with varying functionality,which has promising application potential in a large number of industrial areas.In this study,two components composed of ERCuAl-A2 aluminum bronze(CuAl9)and Inconel 718 nickel-based superalloy were fabricated with different deposition orders by wire-arc directed energy deposition.Subject to changes in heat input and thermophysical properties of the substrate,the transition region of the deposited Cu-Ni component with the bottom half of CuAl9 and the top half of Inconel 718 is narrow and serrated.This region features a laminated intermetallic compound layer due to the convection and rapid cooling in the molten pool.In contrast,the Ni-Cu component deposited in the opposite order exhibits a 2 mm gradient transition zone.Within this region,a large number of diverse precipitates were found as well as regional variations in grain size due to the multi-layer partial remelting.Both two components show strong bonds and their tensile specimens tested along the vertical direction always fracture at the softer CuAl9 side.Excellent tensile properties along the horizontal direction were obtained for Cu-Ni(Ultimate tensile strength:573 MPa,yield stress:302 MPa,elongation:22%),while those of Ni-Cu are much lower due to the existence of the solidification cracks in the transition zone.The results from this study provide a reference for the additive manufacturing of Cu/Ni dissimilar alloy components,as well as their microstructure and mechanical properties control.展开更多
The wide application of additive-manufactured Ti alloys is impeded by coarse columnar grains along the building direction and thus the severe anisotropy of mechanical properties.To address this issue,a novel multiallo...The wide application of additive-manufactured Ti alloys is impeded by coarse columnar grains along the building direction and thus the severe anisotropy of mechanical properties.To address this issue,a novel multialloying CoCrMoSi strategy has been developed to produce near-equiaxed grains of a modified Ti6Al4V(TC4)alloy for laser-directed energy deposition(LDED)based on computational thermodynamic and experimental approaches.The results show that the microstructure of the TC4alloy consists of large columnar β grains and α/α'laths with a high aspect ratio of 5.73,exhibiting a strong anisotropy of tensile properties.In contrast,the TC4-1.5%CoCrMoSi alloy is characterized by mixed columnarequiaxed β grains and near-equiaxed β grains with increased CoCrMoSi additions to 4.5%.Additionally,the α/α'laths are successively refined with the increase of CoCrMoSi content,showing an aspect ratio of smaller than4.31.However,an excess addition of CoCrMoSi leads to the formation of micro voids.After multi-alloyingCoCrMoSi,the number density of twins increases remarkably with a substantially reduced width,because of the increased lattice distortion and dislocation density together with the reducedβ→αphase transformation temperature.The anisotropy of the tensile properties can be effectively eliminated by adding 3 wt%CoCrMoSi with an exemplary strength-ductility combination,superior to the LDEDed-modified TC4 alloy in the literature reporting the tensile properties along both horizontal(X)and vertical(Z)directions.The underlaying mechanisms for the evolution of the microstructure and the tensile properties induced by multi-alloying CoCrMoSi were discussed in detail.展开更多
This study investigates the development of novel high-entropy alloys(HEAs)with enhanced mechanical properties through an innovative fabrication method of direct energy deposition(DED).The focus is on the creation of m...This study investigates the development of novel high-entropy alloys(HEAs)with enhanced mechanical properties through an innovative fabrication method of direct energy deposition(DED).The focus is on the creation of metastable core-shell precipitation-strengthened HEAs that exhibit a unique multi-stage terrace-like slip wave toughening mechanism,a novel approach to improving both strength and ductility simultaneously.Mechanical testing reveals that the developed HEAs exhibit superior mechanical proper-ties,including high yield strength,ultimate tensile strength,and exceptional ductility.The improvement in these properties is attributed to the multi-stage terrace-like slip wave toughening mechanism activated by the unique microstructural features.This toughening mechanism involves the sequential activation of slip systems,facilitated by the stress concentration around the core-shell precipitates and the subsequent propagation of slip waves across the material.The terrace-like pattern of these slip waves enhances the material's ability to deform plastically,providing a significant toughening effect while maintaining high strength levels.Furthermore,the study delves into the fundamental interactions between the microstruc-tural elements and the deformation mechanisms.It elucidates how the core-shell precipitates and the matrix cooperate to distribute stress uniformly,delay the onset of necking,and prevent premature failure.This synergistic interaction between the microstructural features and the slip wave toughening mecha-nism is central to the remarkable balance of strength and ductility achieved in the HEAs.The introduction of a multi-stage terrace-like slip wave toughening mechanism offers a new pathway to designing HEAs with an exceptional amalgamation of strength and ductility.展开更多
The unique structure and formation mechanism of medium-entropy alloys(MEAs)generally result in bet-ter comprehensive properties than traditional alloys.However,the strength-ductility trade-offremains a bottleneck,whic...The unique structure and formation mechanism of medium-entropy alloys(MEAs)generally result in bet-ter comprehensive properties than traditional alloys.However,the strength-ductility trade-offremains a bottleneck,which limits their applications.In this study,we designed novel high-performance CrNiCu x MEAs with a heterophase composition by incorporating a Cu-rich phase,and they were fabricated using laser-directed energy deposition(LDED).The results show that synergistic strengthening from multiple phases significantly improved the mechanical properties of the alloys,resulting in a tensile strength of 675 MPa and a ductility of 34.4%,demonstrating an excellent combination of high tensile strength and ductility.The improved mechanical properties of the CrNiCu x medium-entropy alloys are primarily due to the heterophase interfacial strengthening mechanism.In the alloy,numerous semi-coherent and coher-ent interfaces formed between the Cr-rich phase,Cu-rich phase,and the matrix,creating extensive lattice distortions at the interfaces.An increase in the Cu-rich phase content promoted the interaction between phases,enhancing the strain energy of the alloy and the barrier strength of the interfaces.The calcu-latedτint values,ranging from approximately 5.92-6.69 GPa,are significantly higher than those found in traditional alloys,providing a benchmark for designing new high-performance medium-entropy alloys.展开更多
Under the laser directed energy deposition(LDED)process,the rapid melting and solidification usually lead to the emergence of pores and coarse columnar dendrites,which in turn compromise the properties of the deposite...Under the laser directed energy deposition(LDED)process,the rapid melting and solidification usually lead to the emergence of pores and coarse columnar dendrites,which in turn compromise the properties of the deposited alloys.This study introduced in-situ ultrasonic rolling(UR)as an innovative method to enhance the corrosion resistance of LDED specimens,and the microstructural characteristics and their correlation with corrosion resistance were deeply investigated.The findings reveal that the LDED-UR specimen exhibits a reduction in both the fraction and size of pores.Under the influence of severe plastic deformation generated by LDED-UR process,fully equiaxed grains appear with a reduced average size of 28.61μm(compared to63.98μm for the LDED specimen with columnar grains).The electrochemical corrosion resistance of the LDED-UR specimen is significantly enhanced compared to the LDED specimen.This enhanced corrosion resistance can be attributed to the low fraction of small-sized pores,the fine and uniformly distributed Cr-enriched ferrite phase,and the formation of a compact and thick passive film due to dense grain boundaries.The insight of the correlation between microstructure and corrosion behavior opens up a new pathway to enhance the corrosion resistance of LDED specimens.展开更多
To enhance the anti-corrosion performance of TC4 alloy across a wide temperature range for modern aircrafts operating in increasingly harsh environments, the (TiB+TiC) hybrid reinforced TC4 composites were prepared by...To enhance the anti-corrosion performance of TC4 alloy across a wide temperature range for modern aircrafts operating in increasingly harsh environments, the (TiB+TiC) hybrid reinforced TC4 composites were prepared by laser melting deposition (LMD) via the in-situ reaction between B_(4)C reinforcement and molten TC4 alloy. The effect of B_(4)C content (0, 0.5, 1.5, wt%) on the microstructure and room/high-temperature corrosion behaviour of the composites was investigated. Microstructural analysis revealed that the microstructure of the composites was significantly influenced by the B_(4)C content. The composite containing 0.5 wt% B_(4)C exhibited an optimal microstructure characterized by refined grains, equiaxed α-Ti transformed from lath-shaped α-Ti, well-distributed (TiB+TiC) phases with a proper amount and reduced pore/dislocation defects. This composite also demonstrated the best corrosion resistance at both room temperature (25 ℃) and high temperature (800 ℃), which was primarily attributed to its comprehensive advantages including a favorable microstructure, a uniform dispersion of thermally stable (TiB+TiC) phases and a stable passivation film.展开更多
Solution and aging treatment were conducted on the laser directed energy deposition(LDED)-prepared carbon nanotubes(CNTs)-reinforced WE43(CNTs/WE43)layers to optimize their microstructure and surface properties in thi...Solution and aging treatment were conducted on the laser directed energy deposition(LDED)-prepared carbon nanotubes(CNTs)-reinforced WE43(CNTs/WE43)layers to optimize their microstructure and surface properties in this study.The microstructure of the WE43 and CNTs/WE43 layers was systematically compared.The dissolution of divorced eutectics at the grain boundaries was retarded by CNTs during solution treatment.The spot segregation composed of Mg_(24)Y_(5),CNTs,and Zr cores in the solution treated CNTs/WE43 layer presented a slight decreasing in Y content.The grain growth of both types of layers underwent three stages:slow,rapid,and steady-state.The significant inhibitory effect of CNTs on the grain growth of the LDED WE43 matrix was more pronounced than the promoting effect of temperature,resulting in a 47%increase at 510℃ and a 35%increase at 540℃ in the grain growth exponent compared to the WE43 layers at 510℃.During the subsequent aging treatment at 225℃,the precipitation sequences from plate-shaped β″to plate-shaped and globular β′ were observed in both types of layers.CNTs can facilitate an increase in the nucleation rate of precipitates,but without accelerating precipitation hardening rate.The long and short diameters of the precipitates in peak-aged state were decreased by 48.5%and 43.1%by addition of CNTs,respectively.The wear resistance of both the WE43 and CNTs/WE43 layers can be significantly enhanced through solution and aging treatment.The enhancement in wear resistance for the CNTs/WE43 layers is considerably greater than that of the WE43 layers.展开更多
Laser-directed energy deposition(L-DED)is an advanced additive manufacturing technology primarily adopted in metal three-dimensional printing systems.The L-DED process is characterized by various defects,thus necessit...Laser-directed energy deposition(L-DED)is an advanced additive manufacturing technology primarily adopted in metal three-dimensional printing systems.The L-DED process is characterized by various defects,thus necessitating the extensive use of in-situ monitoring to enable real-time adjustments of process parameters by detecting molten-pool features.To address the challenge of accurately extracting the molten-pool morphology from an undetached spatter,an innovative monitoring method based on the U-Net(U-shaped network)is proposed herein.A lightweight architecture accelerates the processing speed,whereas an enhanced loss function incorporating weight maps augments the segmentation precision.The model performance is evaluated by comparing its segmentation accuracy and processing speed with those of the conventional U-Net,using the mean intersection over union(MIoU)as the segmentation metric.The improved model demonstrates superior segmentation accuracy at the interface between the molten pool and spatter,with a peak MIoU of 0.9798 achieved on the test set.Furthermore,this model processes each image in an extremely short time of 17.9 ms.Using this segmentation algorithm,the error in extracting the molten-pool width from single-track experiments is within 0.1 mm.The proposed method for monitoring the molten-pool morphology is suitable for deployment in online monitoring systems,thus providing a foundation for subsequent process-parameter regulation.展开更多
Assessing the behaviour and concentration of waste pollutants deposited between two parallel plates is essential for effective environmental management.Determining the effectiveness of treatment methods in reducing po...Assessing the behaviour and concentration of waste pollutants deposited between two parallel plates is essential for effective environmental management.Determining the effectiveness of treatment methods in reducing pollution scales is made easier by analysing waste discharge concentrations.The waste discharge concentration analysis is useful for assessing how effectively wastewater treatment techniques reduce pollution levels.This study aims to explore the Casson micropolar fluid flow through two parallel plates with the influence of pollutant concentration and thermophoretic particle deposition.To explore the mass and heat transport features,thermophoretic particle deposition and thermal radiation are considered.The governing equations are transformed into ordinary differential equations with the help of suitable similarity transformations.The Runge-Kutta-Fehlberg’s fourthfifth order technique and shooting procedure are used to solve the reduced set of equations and boundary conditions.The integration of a neural network model based on the Levenberg-Marquardt algorithm serves to improve the accuracy of predictions and optimize the analysis of parameters.Graphical outcomes are displayed to analyze the characteristics of the relevant dimensionless parameters in the current problem.Results reveal that concentration upsurges as the micropolar parameter increases.The concentration reduces with an upsurge in the thermophoretic parameter.An upsurge in the external pollutant source variation and the local pollutant external source parameters enhances mass transport.The surface drag force declines for improved values of porosity and micropolar parameters.展开更多
To improve the mechanical properties of 2024 aluminum alloy,a kind of diamond-like carbon(DLC)film was deposited on the surface of 2024 aluminum alloy by plasma-enhanced chemical vapor deposition technique.The effects...To improve the mechanical properties of 2024 aluminum alloy,a kind of diamond-like carbon(DLC)film was deposited on the surface of 2024 aluminum alloy by plasma-enhanced chemical vapor deposition technique.The effects of acetylene gas on the microstructure,hardness,wear resistance,and adhesion of DLC film were investigated by field emission scanning electron microscope,nano-indentation tester,and friction-wear tester.The results indicate that the thickness of the DLC film increases gradually with increasing the proportion of acetylene.There is an obvious transition layer between the DLC film and matrix.When the ratio of argon to acetylene is 1:3,the hardness of DLC film is enhanced significantly because of the content changes of sp^(3) and sp^(2) bonds within the film.At the same time,the friction coefficient of DLC film is reduced.展开更多
Broadband transparent films play a pivotal role in various applications such as lenses and solar cells,particularly porous structured transparent films exhibit significant potential.This study investigates a porous Si...Broadband transparent films play a pivotal role in various applications such as lenses and solar cells,particularly porous structured transparent films exhibit significant potential.This study investigates a porous SiO_(2) refractive index gradient anti-reflective film prepared by atomic layer deposition(ALD).A porous SiO_(2) film with gradual porosity was obtained by phosphoric acid etching of Al_(2)O_(3)/SiO_(2) multilayers with gradient Al2O3 ratios,achieving a gradual decrease in refractive index from the substrate to the surface.The film exhibited an average transmittance as high as 97.8%within the wavelength range from 320 nm to 1200 nm.The environmental adaptability was further enhanced by surface modification using rare earth oxide(REO)La_(2)O_(3),resulting in formation of a lotus leaf-like structure and achieving a water contact angle of 100.0°.These data proved that the modification significantly improved hydrophobic self-cleaning capability while maintaining exceptional transparency of the film.The surface structure of the modified film remained undamaged even after undergoing wipe testing,demonstrating its excellent surface durability.展开更多
Aqueous zinc metal batteries(ZMBs)which are environmentally benign and cheap can be used for grid-scale energy storage,but have a short cycling life mainly due to the poor reversibility of zinc metal anodes in mild aq...Aqueous zinc metal batteries(ZMBs)which are environmentally benign and cheap can be used for grid-scale energy storage,but have a short cycling life mainly due to the poor reversibility of zinc metal anodes in mild aqueous electrolytes.A zincophilic carbon(ZC)layer was deposited on a Zn metal foil at 450°C by the up-stream pyrolysis of a hydrogen-bonded supramolecular substance framework,as-sembled from melamine(ME)and cyanuric acid(CA).The zincophilic groups(C=O and C=N)in the ZC layer guide uniform zinc plating/stripping and eliminate dendrites and side reactions.so that assembled symmetrical batteries(ZC@Zn//ZC@Zn)have a long-term service life of 2500 h at 1 mA cm^(−2) and 1 mAh cm^(−2),which is much longer than that of bare Zn anodes(180 h).In addition,ZC@Zn//V2O5 full batteries have a higher capacity of 174 mAh g^(−1) after 1200 cycles at 2 A g^(−1) than a Zn//V_(2)O_(5) counterpart(100 mAh g^(−1)).The strategy developed for the low-temperat-ure deposition of the ZC layer is a new way to construct advanced zinc metal anodes for ZMBs.展开更多
To address the issues of low accuracy,long time consumption,and high cost of the traditional temperature prediction methods for laser directed energy deposition(LDED),a machine learning model combined with numerical s...To address the issues of low accuracy,long time consumption,and high cost of the traditional temperature prediction methods for laser directed energy deposition(LDED),a machine learning model combined with numerical simulation was proposed to predict the temperature during LDED.A finite element(FE)thermal analysis model was established.The model's accuracy was verified through in-situ monitoring experiments,and a basic database for the predictive model was obtained based on FE simulations.Temperature prediction was performed using a generalized regression neural network(GRNN).To reduce dependence on human experience during GRNN parameter tuning and to enhance model prediction performance,an improved adaptive step-size fruit fly optimization algorithm(ASSFOA)was introduced.Finally,the prediction performance of ASSFOA-GRNN model was compared with that of back-propagation neural network model,GRNN model,and fruit fly optimization algorithm(FOA)-GRNN model.The evaluation metrics included the root mean square error(RMSE),mean absolute error(MAE),coefficient of determination(R^(2)),training time,and prediction time.Results show that the ASSFOA-GRNN model exhibits optimal performance regarding RMSE,MAE,and R^(2) indexes.Although its prediction efficiency is slightly lower than that of the FOA-GRNN model,its prediction accuracy is significantly better than that of the other models.This proposed method can be used for temperature prediction in LDED process and also provide a reference for similar methods.展开更多
基金supported by the Original Exploratory Program of the National Natural Science Foundation of China(No.52450012)。
文摘TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing TiB_(2)coatings have disadvantages such as high equipment costs,complicated processes,and highly toxic gas emissions.This paper proposes an environmentally friendly method,which requires inexpensive equipment and simple processing,for preparing TiB_(2)coating on molybdenum via electrophoretic deposition within Na3AlF6-based molten salts.The produced TiB_(2)layer had an approximate thickness of 60μm and exhibited high density,outstanding hardness(38.2 GPa)and robust adhesion strength(51 N).Additionally,high-temperature oxidation experiments revealed that,at900℃,the TiB_(2)coating provided effective protection to the molybdenum substrate against oxidation for 3 h.This result indicates that the TiB_(2)coating prepared on molybdenum using molten salt electrophoretic deposition possesses good high-temperature oxidation resistance.
基金supported by Royal Academy of Engineering(IF2223B-125)Royal Society(IECR3213107)。
文摘Laser directed energy deposition(LDED)is an emerging branch of metal-based additive manufacturing(AM)processes,offering unprecedented capabilities for high-performance fabrication with complex geometries and near-net shapes.This technology is gathering increasing attention from industries such as biomedical,automotive,and aerospace.However,achieving consistent part quality and desired material properties is challenging due to intricate processing parameters and potential process defects such as dynamic melt-pool behavior and localized heat accumulation.This paper reviews recent advances in on-line quality control,focusing on in-situ measurement and closed-loop control for efficient assurance of LDED-fabricated parts.The quality principles,encompassing accuracy and material performance,are summarized to lay a foundation for understanding the mechanisms of quality defects and influencing factors.This review explores and thoroughly compares advancements in indirect process measurements,such as optical,thermal,and acoustic monitoring with direct quality measurements,including laser-line scanning and operando synchrotron X-ray imaging.Depending on the sensing techniques,this paper highlights a hierarchical control strategy for adaptive parameter regulation on intra-layer and inter-layer scales.The requirements and performance of various state-of-the-art controllers are critically compared to indicate their suitable applications.The importance of machine learning in detecting process anomalies and predicting build quality based on sensory signals is also outlined.Future directions are proposed towards adaptive,automated,and intelligent quality control,with a focus on multi-modal monitoring,physics-informed neural networks for interpretable analysis,and multi-objective control applications.
基金financial support from the National Natural Science Foundation of China(grant 22090060/22090063)Liaoning Province(2023-MS-014)。
文摘Rechargeable aqueous zinc-ion batteries(AZIBs)are widely studied for energy storage because of their high safety,low cost and high energy/power density.However,the practical application of AZIBs is limited by dendrite formation at the zinc anode under high-depth deposition,which results in reduced cycle life and overall performance.Herein,we propose an effective and scalable stepwise deposition approach that integrates uniform nucleation and dense growth through the construction of ultrathin ZnO nanofiber arrays(ZONAs)on the zinc anode surface,along with the introduction of an anionic surfactant(AS)into the electrolyte.This approach yields a uniform,dense and dendrite-free Zn anode during cycling,maintaining stable cycling for 2100 h under a high deposition depth of 10 mAh cm^(-2)at an extremely high current density of 10 m A cm^(-2).Additionally,full cells using MnO_(2)cathodes exhibit stable cycling for 6000cycles at 5 A g^(-1),with a capacity retention of 75%.Furthermore,the pouch-type cell with an area of90 cm2delivers a capacity of 60 m Ah and maintains stable cycling for 540 cycles at 200 mA,highlighting its strong potential for scalability.
文摘To study the characteristics of atmospheric dry and wet deposition in the upper reaches of Baiyangdian,two sampling sites in Baoding City were monitored for 1 year from September 2018 to August 2019.The results showed that the dry and wet deposition fluxes of total nitrogen(TN)during the monitoring period were 6.87 and 6.46 kg/(hm^(2)·a),respectively.The ratio of wet to dry deposition of TN was approximately 1∶1,with wet deposition being dominated by ammonium nitrogen deposition.The dry and wet deposition fluxes of total phosphorus(TP)were 0.228 and 0.125 kg/(hm^(2)·a),and it was dominated by dry deposition.The average concentration of TN in wet deposition exceeded the standard threshold for eutrophic waters,and its ecological effects on the Baiyangdian basin should be concerned.Wet deposition fluxes of nitrogen and phosphorus had a significantly positive correlation with rainfall,while their deposition concentrations were negatively correlated with rainfall.The dry deposition of atmospheric nitrogen and phosphorus was influenced by the amount of dustfall and climatic factors such as rainfall,temperature,and humidity,which mainly occurred from April to August.
基金supported by the National Key Research and Development Project[grant numbers 2016YFD0800302 and 2017YFC0210103]。
文摘There is increasing interest in understanding atmospheric phosphorus(P)deposition and its impacts on plant pro-ductivity and carbon sinks in ecosystems.However,the global pattern of P deposition remains poorly understood,primarily due to the sparseness of data in Asia.In this study,the authors compiled 396 published observations of atmospheric P deposition from 1959 to 2020 on the global scale.The results gave a geometric mean bulk P deposition value of 0.32 kg ha−1 yr−1,or a global P budget of 4.4 Tg yr−1.Compared with the period 1959-2000,the authors found an elevated P deposition in Europe and Asia during 2001-2020,likely due to the increas-ing agricultural emissions and fossil fuel combustion-related sources in addition to dust emissions.The findings highlight the need to quantify the impacts of elevated P deposition from anthropogenic emissions on long-term ecosystem development in the context of carbon neutrality and clean-air actions.
基金Supported by National Natural Science Foundation of China,No.82170651and the Research Support Fund of Hubei Microcirculation Society,No.HBWXH2024(1)-1.
文摘Intrapancreatic fat deposition(IPFD)has garnered increasing attention in recent years.The prevalence of IPFD is relatively high and associated with factors such as obesity,age,and sex.However,the pathophysiological mechanisms underlying IPFD remain unclear,with several potential contributing factors,including oxida-tive stress,alterations in the gut microbiota,and hormonal imbalances.IPFD was found to be highly correlated with the occurrence and prognosis of exocrine pan-creatic diseases.Although imaging techniques remain the primary diagnostic approach for IPFD,an expanding array of biomarkers and clinical scoring systems have been identified for screening purposes.Currently,effective treatments for IPFD are not available;however,existing medications,such as glucagon-like peptide-1 receptor agonists,and new therapeutic approaches explored in animal models have shown considerable potential for managing this disease.This paper reviews the pathogenesis of IPFD,its association with exocrine pancreatic disea-ses,and recent advancements in its diagnosis and treatment,emphasizing the significant clinical relevance of IPFD.
基金Supported by Jilin Provincial Scientific and Technological Development Program(20230508109RC,20230201051GX,20220201091GX)National Natural Science Foundation of China(62035013,61275235)。
文摘Aqueous zinc-ion electrochromic(EC)technology,boasting the capability to fulfill both safety and cost-ef⁃fectiveness requirements,is garnering extensive attention in various application areas including smart windows,thermal management,displays,and camouflage.However,typical inorganic EC materials,such as tungsten oxides(WO_(3)),of⁃ten suffer from slow ion diffusion kinetics and limited optical contrast within the aqueous Zn^(2+)electrolyte because of the large size and strong Coulombic interactions of the Zn^(2+),which limits their wide applicability.Here,ordered WO_(3)nanowire films,constructed by a one-step grazing angle deposition method,is demonstrated to boost the response speed and optical contrast during EC phenomena.Compared with dense films,the ordered WO_(3)nanowire films with a porosity of 44.6%demonstrate anti-reflective property and excellent comprehensive EC performance,including fast response time(3.6 s and 1.2 s for coloring and bleaching,respectively),large optical contrast(66.6%at 700 nm)and high col⁃oration efficiency(64.3 cm^(2)·C^(-1)).A large-area prototype EC device(17 cm×12 cm)with fast color-switching is also successfully achieved.Mechanistic studies show that the improved performance is mainly due to the ordered porous nanowire structures,which provides direct electron transfer paths and sufficient interfacial contacts,thus simultaneously enhancing the electrochemical activity and fast redox kinetics.This study provides a simple and effective strategy to im⁃prove the performance of tungsten oxide-based aqueous zinc ion EC materials and devices.
基金supported by the Key Research and Development Program of Shaanxi Province(2023-YBGY361)the National Natural Science Foundation of China(52275374 and 52205414)+1 种基金the Postdoctoral Fellowship Program of CPSF(GZC20232098)as well as the Xiaomi Foundation through Xiaomi Young Scholar Program。
文摘The layer-by-layer deposition strategy of additive manufacturing makes it ideal to fabricate dissimilar alloy components with varying functionality,which has promising application potential in a large number of industrial areas.In this study,two components composed of ERCuAl-A2 aluminum bronze(CuAl9)and Inconel 718 nickel-based superalloy were fabricated with different deposition orders by wire-arc directed energy deposition.Subject to changes in heat input and thermophysical properties of the substrate,the transition region of the deposited Cu-Ni component with the bottom half of CuAl9 and the top half of Inconel 718 is narrow and serrated.This region features a laminated intermetallic compound layer due to the convection and rapid cooling in the molten pool.In contrast,the Ni-Cu component deposited in the opposite order exhibits a 2 mm gradient transition zone.Within this region,a large number of diverse precipitates were found as well as regional variations in grain size due to the multi-layer partial remelting.Both two components show strong bonds and their tensile specimens tested along the vertical direction always fracture at the softer CuAl9 side.Excellent tensile properties along the horizontal direction were obtained for Cu-Ni(Ultimate tensile strength:573 MPa,yield stress:302 MPa,elongation:22%),while those of Ni-Cu are much lower due to the existence of the solidification cracks in the transition zone.The results from this study provide a reference for the additive manufacturing of Cu/Ni dissimilar alloy components,as well as their microstructure and mechanical properties control.
基金financially supported by the National Natural Science Foundation of China(No.52375341)Hunan Provincial Natural Science Foundation(No.2022JJ30494)
文摘The wide application of additive-manufactured Ti alloys is impeded by coarse columnar grains along the building direction and thus the severe anisotropy of mechanical properties.To address this issue,a novel multialloying CoCrMoSi strategy has been developed to produce near-equiaxed grains of a modified Ti6Al4V(TC4)alloy for laser-directed energy deposition(LDED)based on computational thermodynamic and experimental approaches.The results show that the microstructure of the TC4alloy consists of large columnar β grains and α/α'laths with a high aspect ratio of 5.73,exhibiting a strong anisotropy of tensile properties.In contrast,the TC4-1.5%CoCrMoSi alloy is characterized by mixed columnarequiaxed β grains and near-equiaxed β grains with increased CoCrMoSi additions to 4.5%.Additionally,the α/α'laths are successively refined with the increase of CoCrMoSi content,showing an aspect ratio of smaller than4.31.However,an excess addition of CoCrMoSi leads to the formation of micro voids.After multi-alloyingCoCrMoSi,the number density of twins increases remarkably with a substantially reduced width,because of the increased lattice distortion and dislocation density together with the reducedβ→αphase transformation temperature.The anisotropy of the tensile properties can be effectively eliminated by adding 3 wt%CoCrMoSi with an exemplary strength-ductility combination,superior to the LDEDed-modified TC4 alloy in the literature reporting the tensile properties along both horizontal(X)and vertical(Z)directions.The underlaying mechanisms for the evolution of the microstructure and the tensile properties induced by multi-alloying CoCrMoSi were discussed in detail.
文摘This study investigates the development of novel high-entropy alloys(HEAs)with enhanced mechanical properties through an innovative fabrication method of direct energy deposition(DED).The focus is on the creation of metastable core-shell precipitation-strengthened HEAs that exhibit a unique multi-stage terrace-like slip wave toughening mechanism,a novel approach to improving both strength and ductility simultaneously.Mechanical testing reveals that the developed HEAs exhibit superior mechanical proper-ties,including high yield strength,ultimate tensile strength,and exceptional ductility.The improvement in these properties is attributed to the multi-stage terrace-like slip wave toughening mechanism activated by the unique microstructural features.This toughening mechanism involves the sequential activation of slip systems,facilitated by the stress concentration around the core-shell precipitates and the subsequent propagation of slip waves across the material.The terrace-like pattern of these slip waves enhances the material's ability to deform plastically,providing a significant toughening effect while maintaining high strength levels.Furthermore,the study delves into the fundamental interactions between the microstruc-tural elements and the deformation mechanisms.It elucidates how the core-shell precipitates and the matrix cooperate to distribute stress uniformly,delay the onset of necking,and prevent premature failure.This synergistic interaction between the microstructural features and the slip wave toughening mecha-nism is central to the remarkable balance of strength and ductility achieved in the HEAs.The introduction of a multi-stage terrace-like slip wave toughening mechanism offers a new pathway to designing HEAs with an exceptional amalgamation of strength and ductility.
基金supported by the National Natural Science Foundation of China(Grant No.U2341254)the National Natural Science Foundation of China(Grant No.52071124),the Natural Science Foundation of Jiangsu Province(No.BK20230502)the Jiangsu Funding Program for Excellent Postdoctoral Talent(No.2022ZB547).
文摘The unique structure and formation mechanism of medium-entropy alloys(MEAs)generally result in bet-ter comprehensive properties than traditional alloys.However,the strength-ductility trade-offremains a bottleneck,which limits their applications.In this study,we designed novel high-performance CrNiCu x MEAs with a heterophase composition by incorporating a Cu-rich phase,and they were fabricated using laser-directed energy deposition(LDED).The results show that synergistic strengthening from multiple phases significantly improved the mechanical properties of the alloys,resulting in a tensile strength of 675 MPa and a ductility of 34.4%,demonstrating an excellent combination of high tensile strength and ductility.The improved mechanical properties of the CrNiCu x medium-entropy alloys are primarily due to the heterophase interfacial strengthening mechanism.In the alloy,numerous semi-coherent and coher-ent interfaces formed between the Cr-rich phase,Cu-rich phase,and the matrix,creating extensive lattice distortions at the interfaces.An increase in the Cu-rich phase content promoted the interaction between phases,enhancing the strain energy of the alloy and the barrier strength of the interfaces.The calcu-latedτint values,ranging from approximately 5.92-6.69 GPa,are significantly higher than those found in traditional alloys,providing a benchmark for designing new high-performance medium-entropy alloys.
基金financial supports from the National Natural Science Foundation of China (No.52305440)the Natural Science Foundation of Changsha City (Nos.kq2208272,kq2208274)+1 种基金the Tribology Science Fund of the State Key Laboratory of Tribology in Advanced Equipment (SKLTKF22B09)the National Key Research and Development Program of China (2022YFB3706902)。
文摘Under the laser directed energy deposition(LDED)process,the rapid melting and solidification usually lead to the emergence of pores and coarse columnar dendrites,which in turn compromise the properties of the deposited alloys.This study introduced in-situ ultrasonic rolling(UR)as an innovative method to enhance the corrosion resistance of LDED specimens,and the microstructural characteristics and their correlation with corrosion resistance were deeply investigated.The findings reveal that the LDED-UR specimen exhibits a reduction in both the fraction and size of pores.Under the influence of severe plastic deformation generated by LDED-UR process,fully equiaxed grains appear with a reduced average size of 28.61μm(compared to63.98μm for the LDED specimen with columnar grains).The electrochemical corrosion resistance of the LDED-UR specimen is significantly enhanced compared to the LDED specimen.This enhanced corrosion resistance can be attributed to the low fraction of small-sized pores,the fine and uniformly distributed Cr-enriched ferrite phase,and the formation of a compact and thick passive film due to dense grain boundaries.The insight of the correlation between microstructure and corrosion behavior opens up a new pathway to enhance the corrosion resistance of LDED specimens.
基金supported by the Tianjin Municipal Natural Science Foundation(No.23JCYBJC00040)the National Nat-ural Science Foundation of China(No.52175369)the Tian-jin Research Innovation Project for Postgraduate Students(No.2022SKY134).
文摘To enhance the anti-corrosion performance of TC4 alloy across a wide temperature range for modern aircrafts operating in increasingly harsh environments, the (TiB+TiC) hybrid reinforced TC4 composites were prepared by laser melting deposition (LMD) via the in-situ reaction between B_(4)C reinforcement and molten TC4 alloy. The effect of B_(4)C content (0, 0.5, 1.5, wt%) on the microstructure and room/high-temperature corrosion behaviour of the composites was investigated. Microstructural analysis revealed that the microstructure of the composites was significantly influenced by the B_(4)C content. The composite containing 0.5 wt% B_(4)C exhibited an optimal microstructure characterized by refined grains, equiaxed α-Ti transformed from lath-shaped α-Ti, well-distributed (TiB+TiC) phases with a proper amount and reduced pore/dislocation defects. This composite also demonstrated the best corrosion resistance at both room temperature (25 ℃) and high temperature (800 ℃), which was primarily attributed to its comprehensive advantages including a favorable microstructure, a uniform dispersion of thermally stable (TiB+TiC) phases and a stable passivation film.
基金supported by the National Natural Science Foundation of China(52005264).
文摘Solution and aging treatment were conducted on the laser directed energy deposition(LDED)-prepared carbon nanotubes(CNTs)-reinforced WE43(CNTs/WE43)layers to optimize their microstructure and surface properties in this study.The microstructure of the WE43 and CNTs/WE43 layers was systematically compared.The dissolution of divorced eutectics at the grain boundaries was retarded by CNTs during solution treatment.The spot segregation composed of Mg_(24)Y_(5),CNTs,and Zr cores in the solution treated CNTs/WE43 layer presented a slight decreasing in Y content.The grain growth of both types of layers underwent three stages:slow,rapid,and steady-state.The significant inhibitory effect of CNTs on the grain growth of the LDED WE43 matrix was more pronounced than the promoting effect of temperature,resulting in a 47%increase at 510℃ and a 35%increase at 540℃ in the grain growth exponent compared to the WE43 layers at 510℃.During the subsequent aging treatment at 225℃,the precipitation sequences from plate-shaped β″to plate-shaped and globular β′ were observed in both types of layers.CNTs can facilitate an increase in the nucleation rate of precipitates,but without accelerating precipitation hardening rate.The long and short diameters of the precipitates in peak-aged state were decreased by 48.5%and 43.1%by addition of CNTs,respectively.The wear resistance of both the WE43 and CNTs/WE43 layers can be significantly enhanced through solution and aging treatment.The enhancement in wear resistance for the CNTs/WE43 layers is considerably greater than that of the WE43 layers.
基金supported by National Natural Science Foundation of China(Grant Nos.52305440,52204263)Natural Science Foundation of Changsha City(Grant Nos.kq2208272,kq2208274)+1 种基金Tribology Science Fund of the State Key Laboratory of Tribology in Advanced Equipment(Grant SKLTKF22B09)National Key Research and Development Program of China(2022YFB3706902).
文摘Laser-directed energy deposition(L-DED)is an advanced additive manufacturing technology primarily adopted in metal three-dimensional printing systems.The L-DED process is characterized by various defects,thus necessitating the extensive use of in-situ monitoring to enable real-time adjustments of process parameters by detecting molten-pool features.To address the challenge of accurately extracting the molten-pool morphology from an undetached spatter,an innovative monitoring method based on the U-Net(U-shaped network)is proposed herein.A lightweight architecture accelerates the processing speed,whereas an enhanced loss function incorporating weight maps augments the segmentation precision.The model performance is evaluated by comparing its segmentation accuracy and processing speed with those of the conventional U-Net,using the mean intersection over union(MIoU)as the segmentation metric.The improved model demonstrates superior segmentation accuracy at the interface between the molten pool and spatter,with a peak MIoU of 0.9798 achieved on the test set.Furthermore,this model processes each image in an extremely short time of 17.9 ms.Using this segmentation algorithm,the error in extracting the molten-pool width from single-track experiments is within 0.1 mm.The proposed method for monitoring the molten-pool morphology is suitable for deployment in online monitoring systems,thus providing a foundation for subsequent process-parameter regulation.
文摘Assessing the behaviour and concentration of waste pollutants deposited between two parallel plates is essential for effective environmental management.Determining the effectiveness of treatment methods in reducing pollution scales is made easier by analysing waste discharge concentrations.The waste discharge concentration analysis is useful for assessing how effectively wastewater treatment techniques reduce pollution levels.This study aims to explore the Casson micropolar fluid flow through two parallel plates with the influence of pollutant concentration and thermophoretic particle deposition.To explore the mass and heat transport features,thermophoretic particle deposition and thermal radiation are considered.The governing equations are transformed into ordinary differential equations with the help of suitable similarity transformations.The Runge-Kutta-Fehlberg’s fourthfifth order technique and shooting procedure are used to solve the reduced set of equations and boundary conditions.The integration of a neural network model based on the Levenberg-Marquardt algorithm serves to improve the accuracy of predictions and optimize the analysis of parameters.Graphical outcomes are displayed to analyze the characteristics of the relevant dimensionless parameters in the current problem.Results reveal that concentration upsurges as the micropolar parameter increases.The concentration reduces with an upsurge in the thermophoretic parameter.An upsurge in the external pollutant source variation and the local pollutant external source parameters enhances mass transport.The surface drag force declines for improved values of porosity and micropolar parameters.
基金National Natural Science Foundation of China(52274296,52071091,52001081)College Student Innovation and Entrepreneurship Training Program Project from Guangdong Province in 2023(S20230125)。
文摘To improve the mechanical properties of 2024 aluminum alloy,a kind of diamond-like carbon(DLC)film was deposited on the surface of 2024 aluminum alloy by plasma-enhanced chemical vapor deposition technique.The effects of acetylene gas on the microstructure,hardness,wear resistance,and adhesion of DLC film were investigated by field emission scanning electron microscope,nano-indentation tester,and friction-wear tester.The results indicate that the thickness of the DLC film increases gradually with increasing the proportion of acetylene.There is an obvious transition layer between the DLC film and matrix.When the ratio of argon to acetylene is 1:3,the hardness of DLC film is enhanced significantly because of the content changes of sp^(3) and sp^(2) bonds within the film.At the same time,the friction coefficient of DLC film is reduced.
文摘Broadband transparent films play a pivotal role in various applications such as lenses and solar cells,particularly porous structured transparent films exhibit significant potential.This study investigates a porous SiO_(2) refractive index gradient anti-reflective film prepared by atomic layer deposition(ALD).A porous SiO_(2) film with gradual porosity was obtained by phosphoric acid etching of Al_(2)O_(3)/SiO_(2) multilayers with gradient Al2O3 ratios,achieving a gradual decrease in refractive index from the substrate to the surface.The film exhibited an average transmittance as high as 97.8%within the wavelength range from 320 nm to 1200 nm.The environmental adaptability was further enhanced by surface modification using rare earth oxide(REO)La_(2)O_(3),resulting in formation of a lotus leaf-like structure and achieving a water contact angle of 100.0°.These data proved that the modification significantly improved hydrophobic self-cleaning capability while maintaining exceptional transparency of the film.The surface structure of the modified film remained undamaged even after undergoing wipe testing,demonstrating its excellent surface durability.
基金partially supported by the National Natural Science Foundation of China(22479022)Liaoning Revitalization Talents Program(XLYC2007129)。
文摘Aqueous zinc metal batteries(ZMBs)which are environmentally benign and cheap can be used for grid-scale energy storage,but have a short cycling life mainly due to the poor reversibility of zinc metal anodes in mild aqueous electrolytes.A zincophilic carbon(ZC)layer was deposited on a Zn metal foil at 450°C by the up-stream pyrolysis of a hydrogen-bonded supramolecular substance framework,as-sembled from melamine(ME)and cyanuric acid(CA).The zincophilic groups(C=O and C=N)in the ZC layer guide uniform zinc plating/stripping and eliminate dendrites and side reactions.so that assembled symmetrical batteries(ZC@Zn//ZC@Zn)have a long-term service life of 2500 h at 1 mA cm^(−2) and 1 mAh cm^(−2),which is much longer than that of bare Zn anodes(180 h).In addition,ZC@Zn//V2O5 full batteries have a higher capacity of 174 mAh g^(−1) after 1200 cycles at 2 A g^(−1) than a Zn//V_(2)O_(5) counterpart(100 mAh g^(−1)).The strategy developed for the low-temperat-ure deposition of the ZC layer is a new way to construct advanced zinc metal anodes for ZMBs.
基金National Key Research and Development Program of China(2022YFB4602200)。
文摘To address the issues of low accuracy,long time consumption,and high cost of the traditional temperature prediction methods for laser directed energy deposition(LDED),a machine learning model combined with numerical simulation was proposed to predict the temperature during LDED.A finite element(FE)thermal analysis model was established.The model's accuracy was verified through in-situ monitoring experiments,and a basic database for the predictive model was obtained based on FE simulations.Temperature prediction was performed using a generalized regression neural network(GRNN).To reduce dependence on human experience during GRNN parameter tuning and to enhance model prediction performance,an improved adaptive step-size fruit fly optimization algorithm(ASSFOA)was introduced.Finally,the prediction performance of ASSFOA-GRNN model was compared with that of back-propagation neural network model,GRNN model,and fruit fly optimization algorithm(FOA)-GRNN model.The evaluation metrics included the root mean square error(RMSE),mean absolute error(MAE),coefficient of determination(R^(2)),training time,and prediction time.Results show that the ASSFOA-GRNN model exhibits optimal performance regarding RMSE,MAE,and R^(2) indexes.Although its prediction efficiency is slightly lower than that of the FOA-GRNN model,its prediction accuracy is significantly better than that of the other models.This proposed method can be used for temperature prediction in LDED process and also provide a reference for similar methods.
