Single carbon products(C1 compounds) are simple but important chemicals in the road towards energy transition.Catalytic conversion of CO_(2) with H_(2)(desirably renewable) can be performed over reducible oxides suppo...Single carbon products(C1 compounds) are simple but important chemicals in the road towards energy transition.Catalytic conversion of CO_(2) with H_(2)(desirably renewable) can be performed over reducible oxides supporting transition metals to obtain products such as CH_(4),CO and MeOH.Oxygen vacancies(O-vacancies),which are inherent defects of reducible metal oxides,play an enormous role in driving the catalytic performance(activity,selectivity,stability) for the desired reactions.Yet,the assessment of O-defects at realistic conditions is often complex.Only few techniques can provide direct evidence for their existence and influence in CO_(2) activation.Among them,electron paramagnetic spectroscopy(EPR),Raman spectroscopy,scanning probe microscopies(SPM) and environmental transmission electron microscopy(ETEM) are nowadays the most informative.In most cases,however,the measurements require reaction conditions far away from CO_(2) valorization applications.Although great efforts have been fruitful in explaining and demonstrating the huge importance of O-vacancies in CO_(2) catalysis,still ambiguous or erroneous interpretations about structure-function correlations involving O-vacancies are found in literature,especially,when information is not properly gathered,e.g.,by O 1s ex-situ X-ray photon spectroscopy(XPS).Moreover,despite the recognized importance of O-vacancies for CO_(2) valorization,critical literature compilations about their effects in thermal processes are scarce.Herein,we attempt to contribute in closing this gap by integrally encompassing representative investigations on the thermo-catalytic production of CH_(4),CO and MeOH.Particularly,we emphasize on the proper selection of assessment tools(direct/indirect) to unambiguously establish structure-function relationships to design optimized O-defective catalysts for the targeted compounds.展开更多
Herein,we established a Zn_(3)(OH)_(2)(V_(2)O_(7))(H_(2)O)_(2)/V-Zn(O,S)Z-scheme heterojunction labeled ZnVO/V-Zn(O,S)with a heterovalent V^(4+)/V^(5+)states and oxygen vacancies in both phases via a one-step in-situ ...Herein,we established a Zn_(3)(OH)_(2)(V_(2)O_(7))(H_(2)O)_(2)/V-Zn(O,S)Z-scheme heterojunction labeled ZnVO/V-Zn(O,S)with a heterovalent V^(4+)/V^(5+)states and oxygen vacancies in both phases via a one-step in-situ hydrolysis method.The NaBH_(4) regulated the ZnVO/V-Zn(O,S)-3 with rich Vo and suitable n(V^(4+))/n(V^(5+))ratio achieved an excellent photocatalytic nitrogen fixation activity of 301.7μmol/(g×h)and apparent quantum efficiency of 1.148%at 420 nm without any sacrificial agent,which is 11 times than that of V-Zn(O,S).The Vo acts as the active site to trap and activate N_(2) molecules and to trap and activate H_(2)O to produce the H for N_(2) molecules photocatalytic reduction.The rich Vo defects can also reduce the competitive adsorption of H_(2)O and N_(2) molecules on the surface active site of the catalyst.The heterovalent vanadium states act as the photogenerated electrons,quickly hopping between V^(4+)and V^(5+)to transfer for the photocatalytic N_(2) reduction reaction.Additionally,the Z-scheme heterojunction effectively minimizes photogenerated carrier recombination.These synergistic effects collectively boost the photocatalytic nitrogen fixation activity.This study provides a practical method for designing Z-scheme heterojunctions for efficient photocatalytic N_(2) fixation under mild conditions.展开更多
Based on inspection data,the authors analyze and summarize the main types and distribution characteristics of tunnel structural defects.These defects are classified into three types:surface defects,internal defects,an...Based on inspection data,the authors analyze and summarize the main types and distribution characteristics of tunnel structural defects.These defects are classified into three types:surface defects,internal defects,and defects behind the structure.To address the need for rapid detection of different defect types,the current state of rapid detection technologies and equipment,both domestically and internationally,is systematically reviewed.The research reveals that surface defect detection technologies and equipment have developed rapidly in recent years.Notably,the integration of machine vision and laser scanning technologies have significantly improved detection efficiency and accuracy,achieving crack detection precision of up to 0.1 mm.However,the non-contact rapid detection of internal and behind-the-structure defects remains constrained by hardware limitations,with traditional detection remaining dominant.Nevertheless,phased array radar,ultrasonic,and acoustic vibration detection technologies have become research hotspots in recent years,offering promising directions for detecting these challenging defect types.Additionally,the application of multisensor fusion technology in rapid detection equipment has further enhanced detection capabilities.Devices such as cameras,3D laser scanners,infrared thermal imagers,and radar demonstrate significant advantages in rapid detection.Future research in tunnel inspection should prioritize breakthroughs in rapid detection technologies for internal and behind-the-structure defects.Efforts should also focus on developing multifunctional integrated detection vehicles that can simultaneously inspect both surface and internal structures.Furthermore,progress in fully automated,intelligent systems with precise defect identification and real-time reporting will be essential to significantly improve the efficiency and accuracy of tunnel inspection.展开更多
Selective catalytic reduction of NO_(x) with CO(CO-SCR)is a process that purifies both NO and CO pollutants through a catalytic reaction.Specifically,the cleavage of NO on the catalyst surface is crucial for promoting...Selective catalytic reduction of NO_(x) with CO(CO-SCR)is a process that purifies both NO and CO pollutants through a catalytic reaction.Specifically,the cleavage of NO on the catalyst surface is crucial for promoting the reaction.During the reaction,the presence of oxygen vacancies can extract oxygen from NO,thereby facilitating the cleavage of NO on the catalyst surface.Thus,the formation of oxygen vacancies is key to accelerating the CO-SCR reaction,with different types of oxygen vacancies being more conducive to their generation.In this study,Rh/CeCuO_(x) catalysts were synthesized using the co-crystallization and impregnation methods,and asymmetric oxygen vacancies were induced through hydrogen thermal treatment.This structuralmodification was aimed at regulating the behavior of NO on the catalyst surface.The Rh/Ce0.95Cu0.05O_(x)-H_(2) catalyst exhibited the best performance in CO-SCR,achieving above 90%NO conversion at 162℃.Various characterization techniques showed that the H_(2) treatment effectively reduced some of the CuO and Rh_(2)O_(3),creating asymmetric oxygen vacancies that accelerated the cleavage of NO on the catalyst surface,rather than forming difficult-to-decompose nitrates.This study offers a novel approach to constructing oxygen vacancies in new CO-SCR catalysts.展开更多
In integrated circuit(IC)manufacturing,fast,nondestructive,and precise detection of defects in patterned wafers,realized by bright-field microscopy,is one of the critical factors for ensuring the final performance and...In integrated circuit(IC)manufacturing,fast,nondestructive,and precise detection of defects in patterned wafers,realized by bright-field microscopy,is one of the critical factors for ensuring the final performance and yields of chips.With the critical dimensions of IC nanostructures continuing to shrink,directly imaging or classifying deep-subwavelength defects by bright-field microscopy is challenging due to the well-known diffraction barrier,the weak scattering effect,and the faint correlation between the scattering cross-section and the defect morphology.Herein,we propose an optical far-field inspection method based on the form-birefringence scattering imaging of the defective nanostructure,which can identify and classify various defects without requiring optical super-resolution.The technique is built upon the principle of breaking the optical form birefringence of the original periodic nanostructures by the defect perturbation under the anisotropic illumination modes,such as the orthogonally polarized plane waves,then combined with the high-order difference of far-field images.We validated the feasibility and effectiveness of the proposed method in detecting deep subwavelength defects through rigid vector imaging modeling and optical detection experiments of various defective nanostructures based on polarization microscopy.On this basis,an intelligent classification algorithm for typical patterned defects based on a dual-channel AlexNet neural network has been proposed,stabilizing the classification accuracy ofλ/16-sized defects with highly similar features at more than 90%.The strong classification capability of the two-channel network on typical patterned defects can be attributed to the high-order difference image and its transverse gradient being used as the network’s input,which highlights the polarization modulation difference between different patterned defects more significantly than conventional bright-field microscopy results.This work will provide a new but easy-to-operate method for detecting and classifying deep-subwavelength defects in patterned wafers or photomasks,which thus endows current online inspection equipment with more missions in advanced IC manufacturing.展开更多
Phenanthrene(Phe)is one of the common polycyclic aromatic hydrocarbons in the environment,and recent studies show that it can cause cardiac developmental toxicity and immunotoxicity.However,it is still unknown whether...Phenanthrene(Phe)is one of the common polycyclic aromatic hydrocarbons in the environment,and recent studies show that it can cause cardiac developmental toxicity and immunotoxicity.However,it is still unknown whether it can affect the hematopoietic development in aquatic organisms.To address this question,zebrafish(Danio rerio)were chronically exposed to Phe at different concentrations.We found that Phe caused structural damage to the renal tubules in the kidney,induced malformed erythrocytes in peripheral blood,and decreased the proportion of myeloid cells in adult zebrafish,suggesting possible negative impacts that Phe posed to hematopoietic development.Then,using in situ hybridization technology,we found that Phe decreased the expression of primitive hematopoietic marker genes,specifically gata1 and pu.1,accompanied by an obstruction of primitive erythrocyte circulation.Furthermore,Phe impaired definitive hematopoiesis,increased aberrations of the transient hematopoietic site(PBI),and reduced the generation of hematopoietic stem cells,ultimately influencing the number of erythrocytes and myeloid cells.The findings suggested that Phe could induce hematopoietic toxicity in zebrafish embryos and pose unknown ecological risks.展开更多
With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,off...With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,offers a promising avenue for researchers.However,the question of how to significantly enhance the performance of catalysts has gradually drawn the attention of scholars.Defect engineering,a commonly employed and effective approach to improve catalyst activity,has become a significant research focus in the catalysis field in recent years.Nonmetal vacancies have received extensive attention due to their simple form.Consequently,exploration of metal vacancies has remained stagnant for a considerable period,resulting in a scarcity of comprehensive reviews on this topic.Therefore,based on the latest research findings,this paper summarizes and consolidates the construction strategies for metal vacancies,characterization techniques,and their roles in typical energy and environmental catalytic reactions.Additionally,it outlines potential challenges in the future,aiming to provide valuable references for researchers interested in investigating metal vacancies.展开更多
Lithium-sulfur (Li-S) batteries have gained great attention due to the high theoretical energy density and low cost,yet their further commercialization has been obstructed by the notorious shuttle effect and sluggish ...Lithium-sulfur (Li-S) batteries have gained great attention due to the high theoretical energy density and low cost,yet their further commercialization has been obstructed by the notorious shuttle effect and sluggish redox dynamics.Herein,we supply a strategy to optimize the electron structure of Ni_(2)P by concurrently introducing B-doped atoms and P vacancies in Ni_(2)P (Vp-B-Ni_(2)P),thereby enhancing the bidirectional sulfur conversion.The study indicates that the simultaneous introduction of B-doped atoms and P vacancies in Ni_(2)P causes the redistribution of electron around Ni atoms,bringing about the upward shift of d-band center of Ni atoms and effective d-p orbital hybridization between Ni atoms and sulfur species,thus strengthening the chemical anchoring for lithium polysulfides (LiPSs) as well as expediting the bidirectional conversion kinetics of sulfur species.Meanwhile,theoretical calculations reveal that the incorporation of B-doped atoms and P vacancies in Ni_(2)P selectively promotes Li2S dissolution and nucleation processes.Thus,the Li-S batteries with Vp-B-Ni_(2)P-separators present outstanding rate ability of 777 m A h g^(-1)at 5 C and high areal capacity of 8.03 mA h cm^(-2)under E/S of 5μL mg^(-1)and sulfur loading of 7.20 mg cm^(-2).This work elucidates that introducing heteroatom and vacancy in metal phosphide collaboratively regulates the electron structure to accelerate bidirectional sulfur conversion.展开更多
As the global population ages,osteoporotic bone fractures leading to bone defects are increasingly becoming a significant challenge in the field of public health.Treating this disease faces many challenges,especially ...As the global population ages,osteoporotic bone fractures leading to bone defects are increasingly becoming a significant challenge in the field of public health.Treating this disease faces many challenges,especially in the context of an imbalance between osteoblast and osteoclast activities.Therefore,the development of new biomaterials has become the key.This article reviews various design strategies and their advantages and disadvantages for biomaterials aimed at osteoporotic bone defects.Overall,current research progress indicates that innovative design,functionalization,and targeting of materials can significantly enhance bone regeneration under osteoporotic conditions.By comprehensively considering biocompatibility,mechanical properties,and bioactivity,these biomaterials can be further optimized,offering a range of choices and strategies for the repair of osteoporotic bone defects.展开更多
To solve the problem of low detection accuracy for complex weld defects,the paper proposes a weld defects detection method based on improved YOLOv5s.To enhance the ability to focus on key information in feature maps,t...To solve the problem of low detection accuracy for complex weld defects,the paper proposes a weld defects detection method based on improved YOLOv5s.To enhance the ability to focus on key information in feature maps,the scSE attention mechanism is intro-duced into the backbone network of YOLOv5s.A Fusion-Block module and additional layers are added to the neck network of YOLOv5s to improve the effect of feature fusion,which is to meet the needs of complex object detection.To reduce the computation-al complexity of the model,the C3Ghost module is used to replace the CSP2_1 module in the neck network of YOLOv5s.The scSE-ASFF module is constructed and inserted between the neck network and the prediction end,which is to realize the fusion of features between the different layers.To address the issue of imbalanced sample quality in the dataset and improve the regression speed and accuracy of the loss function,the CIoU loss function in the YOLOv5s model is replaced with the Focal-EIoU loss function.Finally,ex-periments are conducted based on the collected weld defect dataset to verify the feasibility of the improved YOLOv5s for weld defects detection.The experimental results show that the precision and mAP of the improved YOLOv5s in detecting complex weld defects are as high as 83.4%and 76.1%,respectively,which are 2.5%and 7.6%higher than the traditional YOLOv5s model.The proposed weld defects detection method based on the improved YOLOv5s in this paper can effectively solve the problem of low weld defects detection accuracy.展开更多
The conversion of urea-containing wastewater into clean hydrogen energy has gained increasing attention.However,challenges remain,particularly with sluggish catalytic kinetics and limited long-term stability of urea o...The conversion of urea-containing wastewater into clean hydrogen energy has gained increasing attention.However,challenges remain,particularly with sluggish catalytic kinetics and limited long-term stability of urea oxidation reaction(UOR).Herein,we report the loosely porous CoOOH nano-architecture(CoOOH LPNAs)with hydrophilic surface and abundant oxygen vacancies(Ov)on carbon fiber paper(CFP)by electrochemical reconstruction of the CoP nanoneedles precursor.The resulting three-dimensional electrode exhibited an impressively low potential of 1.38 V at 1000 mA·cm^(−2) and excellent durability for UOR.Furthermore,when tested in an anion exchange membrane(AEM)electrolyzer,it required only 1.53 V at 1000 mA·cm^(−2) for industrial urea-assisted water splitting and operated stably for 100 h without degrada-tion.Experimental and theoretical investigations revealed that rich oxygen vacancies effectively modulate the electronic structure of the CoOOH while creating unique Co3-triangle sites with Co atoms close together.As a result,the adsorption and desorption processes of reactants and intermediates in UOR could be finely tuned,thereby significantly reducing ther-modynamic barriers.Additionally,the superhydrophilic self-supported nanoarray structure facilitated rapid gas bubble release,improving the overall efficiency of the reaction and preventing potential catalyst detachment caused by bubble accumulation,thereby improving both catalytic activity and stability at high current densities.展开更多
The impact of casting defects on the weldability of K4951 superalloy was investigated using tungsten inert gas(TIG)welding.The as-cast K4951 superalloy samples with prefabricated U-shaped grooves of varying depths and...The impact of casting defects on the weldability of K4951 superalloy was investigated using tungsten inert gas(TIG)welding.The as-cast K4951 superalloy samples with prefabricated U-shaped grooves of varying depths and widths were TIG welded,and the microstructures,cracks morphology,and precipitated phases were analyzed using optical microscope,scanning electron microscope,transmission electron microscope,and energy dispersive X-ray spectrometer.The results reveal that the dimensions of casting defects significantly affect the weldability of K4951.Deep defects(greater than 2 mm)lead to rapid crack propagation,while wider defects can moderate the propagation process of cracks.Elemental segregation and the formation of precipitated phases,such as MC carbides,are observed in the fusion zone,contributing to welding cracks.An optimal groove aspect ratio(depth-to-width)between 0.2 and 0.5 minimizes crack formation tendency and enhances tensile strength,resulting in a mixed brittle-ductile fracture mode of joint after high-temperature tensile testing.展开更多
Achieving high-quality perovskite films without surface defects is regarded as a crucial target for the development of durable high-performance perovskite solar cells.Additive engineering is commonly employed to simul...Achieving high-quality perovskite films without surface defects is regarded as a crucial target for the development of durable high-performance perovskite solar cells.Additive engineering is commonly employed to simultaneously control the growth of perovskite crystals and passivate defects.Here,4-(trifluoromethyl)benzoic anhydride(4-TBA)composed of benzene rings functionalized with carbonyl and trifluoromethyl groups was used as an example additive to study the characteristics of additives used for producing high-quality perovskites and controlling their surface properties.The interaction between4-TBA and perovskite precursor materials was investigated using density functional theory(DFT)simulations.The electron-rich carbonyl group efficiently passivated the under-coordinated lead-ion defects.Additionally,hydrogen bonding between trifluoromethyl and organic cations prevents the generation of cation vacancies.Because of its intrinsic hydrophobicity,the trifluoromethyl group simultaneously improves the moisture and heat stability of the film.4-TBA serves as a universal modifier for various perovskite compositions.The power conversion efficiency(PCE)of inverted perovskite solar cells(PSCs)based on methylammonium(MA)with 4-TBA was improved from 16.15%to 19.28%.Similarly,the PCE of inverted PSCs based on a cesium formamidinium MA(CsFAMA)perovskite film increased from20.72%to 23.58%,upon addition of 4-TBA.Furthermore,the moisture and thermal stability of 4-TBAtreated films and devices was significantly enhanced,along with prolonged device performance.Our work provides guidance on selecting the structure and functional groups that are essential for surface defect passivation and the production of high-quality perovskites.展开更多
Directional design of efficient catalysts for volatile organic compounds degradation remains a complex,yet effective and challenging process.Herein,oxygen-rich vacancy Co_(3)O_(4)-anchored Pt catalysts were prepared t...Directional design of efficient catalysts for volatile organic compounds degradation remains a complex,yet effective and challenging process.Herein,oxygen-rich vacancy Co_(3)O_(4)-anchored Pt catalysts were prepared through atom-trapping strategy and relevant vacancy defect inductive effect was proposed.The 0.6Pt/VO-Co_(3)O_(4)catalyst presented a reaction rate value of 32.2×10^(-5)mol·g_(cat)^(-1)·s^(-1)at 160℃for catalytic propane total oxidation,which was nearly 5 times the reaction rate of Co_(3)O_(4)(6.7×10^(-5)mol·g_(cat)^(-1)·s^(-1)).Also,it exhibited excellent water-resistance and catalytic stability.The Pt atoms were stabilized on the Co_(3)O_(4)surface by vacancy defects to improve dispersion.Meanwhile,the vacancy defect inductive effect induced stronger electron interaction between Pt and Co_(3)O_(4)on the surface,thus promote the redox ability at low-temperature.The mobility and oxygen-activating ability of surface lattice oxygen were also strengthened by the vacancy defect inductive effect.This facilitated the generation of more surface-active oxygen species for the cleavage of C-H bond and the deep oxidation of intermediate species.Overall,this study proposed a novel concept the fabrication of highly efficient catalysts for the purpose of catalytic oxidation.展开更多
Electrocatalyst activity and stability demonstrate a“seesaw”relationship.Introducing vacancies(Vo)enhances the activity by improving reactant affinity and increasing accessible active sites.However,deficient or exce...Electrocatalyst activity and stability demonstrate a“seesaw”relationship.Introducing vacancies(Vo)enhances the activity by improving reactant affinity and increasing accessible active sites.However,deficient or excessive Vo reduces polysulfide adsorption and lowers catalytic stability.Herein,a novel“heteroatoms synergistic anchoring vacancies”strategy is proposed to address the trade-off between high activity and stability.Phosphorus-doped CoSe_(2)with remained rich selenium vacancies(P-CS-Vo-0.5)was synthesized by producing abundant selenium Vo followed by controlled P atom doping.Atomic-scale microstructure analysis elucidated a dynamic process of surface vacancy generation and the subsequent partial occupation of these vacancies by P atoms.Density functional theory simulations and in situ Raman tests revealed that the Se vacancies provide highly active catalytic sites,accelerating polysulfide conversion,while P incorporation effectively reduces the surface energy of Se vacancies and suppresses their inward migration,enhancing structural robustness.The battery with the optimal P-CS-Vo-0.5 separator delivers an initial discharge capacity of 1306.7 mAh g^(-1)at 0.2C,and maintain 5.04 mAh cm^(-2)at a high sulfur loading(5.7 mg cm^(-2),5.0μL mg^(-1)),achieving 95.1%capacity retention after 80 cycles.This strategy of modifying local atomic environments offers a new route to designing highly active and stable catalysts.展开更多
Rail defects can pose significant safety risks in railway operations, raising the need for effective detection methods. Acoustic Emission (AE) technology has shown promise for identifying and monitoring these defects,...Rail defects can pose significant safety risks in railway operations, raising the need for effective detection methods. Acoustic Emission (AE) technology has shown promise for identifying and monitoring these defects, and this study evaluates an advanced on-vehicle AE detection approach using bone-conduct sensors—a solution to improve upon previous AE methods of using on-rail sensor installations, which required extensive, costly on-rail sensor networks with limited effectiveness. In response to these challenges, the study specifically explored bone-conduct sensors mounted directly on the vehicle rather than rails by evaluating AE signals generated by the interaction between rails and the train’s wheels while in motion. In this research, a prototype detection system was developed and tested through initial trials at the Nevada Railroad Museum using a track with pre-damaged welding defects. Further testing was conducted at the Transportation Technology Center Inc. (rebranded as MxV Rail) in Colorado, where the system’s performance was evaluated across various defect types and train speeds. The results indicated that bone-conduct sensors were insufficient for detecting AE signals when mounted on moving vehicles. These findings highlight the limitations of contact-based methods in real-world applications and indicate the need for exploring improved, non-contact approaches.展开更多
In order to explore the effect of vacancy defects on the structural,electronic,magnetic and optical properties of CoS_(2) and FeS_(2),first-principles calculation method was used to investigate the alloys.The calculat...In order to explore the effect of vacancy defects on the structural,electronic,magnetic and optical properties of CoS_(2) and FeS_(2),first-principles calculation method was used to investigate the alloys.The calculated results of materials without vacancy are consistent with those reported in the literatures,while the results of materials with vacancy defect were different from those of literatures due to the difference vacancy concentration.The Co vacancy defect hardly changes the half-metallic characteristic of CoS_(2).The Fe vacancy defect changes FeS_(2) from semiconductor to half-metal,and the bottom of the spin-down conduction band changes from the p orbital state of S to the d(t_(2g))orbital state of Fe,while the top of the valence band remains the d orbital d(eg)state of Fe.The half-metallic Co vacancy defects of CoS_(2) and Fe vacancy defects of FeS_(2) are expected to be used in spintronic devices.S vacancy defects make both CoS_(2) and FeS_(2) metallic.Both the Co and S vacancy defects lead to the decrease of the magnetic moment of CoS_(2),while both the Fe and S vacancy defects lead to the obvious magnetic property of FeS_(2).Vacancy defects enhance the absorption coefficient of infrared band and long band of visible light obviously,and produce obvious red shift phenomenon,which is expected to be used in photoelectric devices.展开更多
The accuracy and reliability of non-destructive testing(NDT)approaches in detecting interior corrosion problems are critical,yet research in this field is limited.This work describes a novel way to monitor the structu...The accuracy and reliability of non-destructive testing(NDT)approaches in detecting interior corrosion problems are critical,yet research in this field is limited.This work describes a novel way to monitor the structural integrity of steel gas pipelines that uses advanced numerical modeling techniques to anticipate fracture development and corrosion effects.The objective is to increase pipeline dependability and safety through more precise,real-time health evaluations.Compared to previous approaches,our solution provides higher accuracy in fault detection and quantification,making it ideal for pipeline integritymonitoring in real-world applications.To solve this issue,statistical analysis was conducted on the size and directional distribution features of about 380,000 sets of internal corrosion faults,as well as simulations of erosion and wear patterns on bent pipes.Using real defectmorphologies,we developed a modeling framework for typical interior corrosion flaws.We evaluated and validated the applicability and effectiveness of in-service inspection processes,as well as conducted on-site comparison tests.The results show that(1)the length and width of corrosion defects follow a log-normal distribution,the clock orientation follows a normal distribution,and the peak depth follows a Freundlich EX function distribution pattern;(2)pipeline corrosion defect data can be classified into three classes using the K-means clustering algorithm,allowing rapid and convenient acquisition of typical size and orientation characteristics of internal corrosion defects;(3)the applicability range and boundary conditions of various NDT techniques were verified,establishing comprehensive selection principles for internal corrosion defect detection technology;(4)on-site inspection results showed a 31%The simulation and validation platform for typical interior corrosion issues greatly enhances the accuracy and reliability of detection data.展开更多
Bisphenol A(BPA)has threatened ecological safety and human health due to its endocrine disrupting effect and widely diffused in the environment.Peroxymonosulfate(PMS)based on oxidation technology exhibits good potenti...Bisphenol A(BPA)has threatened ecological safety and human health due to its endocrine disrupting effect and widely diffused in the environment.Peroxymonosulfate(PMS)based on oxidation technology exhibits good potential for environmental remediation whereas the highly efficient activator needs to be developed.Herein,the Bi OBr(BOB)was synthesized to efficiently activate PMS to remove 95.6%of BPA within 60 min.The observed rate constant of BPA removal in BOB/PMS system is 0.049 min^(-1),which is 60 and 148 times to that of the BOB and PMS processes separately and 129 times to the compared Bi OCl(BOC)/PMS system,respectively.Comparison experiments and analytic methods demonstrate that BOB with a larger content of oxygen vacancies(Ov)can act as the bridge of electron transfer between Bi^(3+)/Bi^(4+)with PMS to enhance the activation ability for PMS,resulting in the production of abundant reactive oxygen species(O_(2)^(·-)and ^(1)O_(2)).Additionally,the breakdown processes of BPA and the toxicity of its byproducts were uncovered,and the potential for actual water treatment was evaluated to confirm the detoxification,efficiency,stability and practical use of the BOB/PMS system for eliminating BPA.This study may widen the application of traditional semiconductors and develop the cost-effective PMS activation methods for environmental remediation.展开更多
Correction to:Nano-Micro Lett.(2025)17:24 https://doi.org/10.1007/s40820-024-01515-0 Following publication of the original article[1],the authors reported the author list needed to be updated because the last three au...Correction to:Nano-Micro Lett.(2025)17:24 https://doi.org/10.1007/s40820-024-01515-0 Following publication of the original article[1],the authors reported the author list needed to be updated because the last three author names were duplicated.The correct author list has been provided in this Correction.The original article[1]has been corrected.展开更多
基金the financial support from the European Commission through the H2020-MSCA-RISE-2020 BIOALL project(Grant Agreement: 101008058)。
文摘Single carbon products(C1 compounds) are simple but important chemicals in the road towards energy transition.Catalytic conversion of CO_(2) with H_(2)(desirably renewable) can be performed over reducible oxides supporting transition metals to obtain products such as CH_(4),CO and MeOH.Oxygen vacancies(O-vacancies),which are inherent defects of reducible metal oxides,play an enormous role in driving the catalytic performance(activity,selectivity,stability) for the desired reactions.Yet,the assessment of O-defects at realistic conditions is often complex.Only few techniques can provide direct evidence for their existence and influence in CO_(2) activation.Among them,electron paramagnetic spectroscopy(EPR),Raman spectroscopy,scanning probe microscopies(SPM) and environmental transmission electron microscopy(ETEM) are nowadays the most informative.In most cases,however,the measurements require reaction conditions far away from CO_(2) valorization applications.Although great efforts have been fruitful in explaining and demonstrating the huge importance of O-vacancies in CO_(2) catalysis,still ambiguous or erroneous interpretations about structure-function correlations involving O-vacancies are found in literature,especially,when information is not properly gathered,e.g.,by O 1s ex-situ X-ray photon spectroscopy(XPS).Moreover,despite the recognized importance of O-vacancies for CO_(2) valorization,critical literature compilations about their effects in thermal processes are scarce.Herein,we attempt to contribute in closing this gap by integrally encompassing representative investigations on the thermo-catalytic production of CH_(4),CO and MeOH.Particularly,we emphasize on the proper selection of assessment tools(direct/indirect) to unambiguously establish structure-function relationships to design optimized O-defective catalysts for the targeted compounds.
文摘Herein,we established a Zn_(3)(OH)_(2)(V_(2)O_(7))(H_(2)O)_(2)/V-Zn(O,S)Z-scheme heterojunction labeled ZnVO/V-Zn(O,S)with a heterovalent V^(4+)/V^(5+)states and oxygen vacancies in both phases via a one-step in-situ hydrolysis method.The NaBH_(4) regulated the ZnVO/V-Zn(O,S)-3 with rich Vo and suitable n(V^(4+))/n(V^(5+))ratio achieved an excellent photocatalytic nitrogen fixation activity of 301.7μmol/(g×h)and apparent quantum efficiency of 1.148%at 420 nm without any sacrificial agent,which is 11 times than that of V-Zn(O,S).The Vo acts as the active site to trap and activate N_(2) molecules and to trap and activate H_(2)O to produce the H for N_(2) molecules photocatalytic reduction.The rich Vo defects can also reduce the competitive adsorption of H_(2)O and N_(2) molecules on the surface active site of the catalyst.The heterovalent vanadium states act as the photogenerated electrons,quickly hopping between V^(4+)and V^(5+)to transfer for the photocatalytic N_(2) reduction reaction.Additionally,the Z-scheme heterojunction effectively minimizes photogenerated carrier recombination.These synergistic effects collectively boost the photocatalytic nitrogen fixation activity.This study provides a practical method for designing Z-scheme heterojunctions for efficient photocatalytic N_(2) fixation under mild conditions.
文摘Based on inspection data,the authors analyze and summarize the main types and distribution characteristics of tunnel structural defects.These defects are classified into three types:surface defects,internal defects,and defects behind the structure.To address the need for rapid detection of different defect types,the current state of rapid detection technologies and equipment,both domestically and internationally,is systematically reviewed.The research reveals that surface defect detection technologies and equipment have developed rapidly in recent years.Notably,the integration of machine vision and laser scanning technologies have significantly improved detection efficiency and accuracy,achieving crack detection precision of up to 0.1 mm.However,the non-contact rapid detection of internal and behind-the-structure defects remains constrained by hardware limitations,with traditional detection remaining dominant.Nevertheless,phased array radar,ultrasonic,and acoustic vibration detection technologies have become research hotspots in recent years,offering promising directions for detecting these challenging defect types.Additionally,the application of multisensor fusion technology in rapid detection equipment has further enhanced detection capabilities.Devices such as cameras,3D laser scanners,infrared thermal imagers,and radar demonstrate significant advantages in rapid detection.Future research in tunnel inspection should prioritize breakthroughs in rapid detection technologies for internal and behind-the-structure defects.Efforts should also focus on developing multifunctional integrated detection vehicles that can simultaneously inspect both surface and internal structures.Furthermore,progress in fully automated,intelligent systems with precise defect identification and real-time reporting will be essential to significantly improve the efficiency and accuracy of tunnel inspection.
基金supported by the support of the National Natural Science Foundation of China(Nos.22072141,22176185 and 52304429)the National Key Research and Development Program of China(Nos.2022YFB3504200,2021YFB3501900)+4 种基金the Natural Science Foundation of Jiangxi Province for Distinguished Young Scholars(No.20232ACB213004)Jiangxi Provincial Key Research and Development Program(No.20232BBG70012)Jiangxi Provincial Natural Science Foundation(No.20212BAB213032)the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2018263)the Research Projects of Ganjiang Innovation Academy,Chinese Academy of Sciences(No.E355C001).
文摘Selective catalytic reduction of NO_(x) with CO(CO-SCR)is a process that purifies both NO and CO pollutants through a catalytic reaction.Specifically,the cleavage of NO on the catalyst surface is crucial for promoting the reaction.During the reaction,the presence of oxygen vacancies can extract oxygen from NO,thereby facilitating the cleavage of NO on the catalyst surface.Thus,the formation of oxygen vacancies is key to accelerating the CO-SCR reaction,with different types of oxygen vacancies being more conducive to their generation.In this study,Rh/CeCuO_(x) catalysts were synthesized using the co-crystallization and impregnation methods,and asymmetric oxygen vacancies were induced through hydrogen thermal treatment.This structuralmodification was aimed at regulating the behavior of NO on the catalyst surface.The Rh/Ce0.95Cu0.05O_(x)-H_(2) catalyst exhibited the best performance in CO-SCR,achieving above 90%NO conversion at 162℃.Various characterization techniques showed that the H_(2) treatment effectively reduced some of the CuO and Rh_(2)O_(3),creating asymmetric oxygen vacancies that accelerated the cleavage of NO on the catalyst surface,rather than forming difficult-to-decompose nitrates.This study offers a novel approach to constructing oxygen vacancies in new CO-SCR catalysts.
基金funded by National Natural Science Foundation of China(Grant Nos.52130504,52305577,and 52175509)the Key Research and Development Plan of Hubei Province(Grant No.2022BAA013)+4 种基金the Major Program(JD)of Hubei Province(Grant No.2023BAA008-2)the Interdisciplinary Research Program of Huazhong University of Science and Technology(2023JCYJ047)the Innovation Project of Optics Valley Laboratory(Grant No.OVL2023PY003)the Postdoctoral Fellowship Program(Grade B)of China Postdoctoral Science Foundation(Grant No.GZB20230244)the fellowship from the China Postdoctoral Science Foundation(2024M750995)。
文摘In integrated circuit(IC)manufacturing,fast,nondestructive,and precise detection of defects in patterned wafers,realized by bright-field microscopy,is one of the critical factors for ensuring the final performance and yields of chips.With the critical dimensions of IC nanostructures continuing to shrink,directly imaging or classifying deep-subwavelength defects by bright-field microscopy is challenging due to the well-known diffraction barrier,the weak scattering effect,and the faint correlation between the scattering cross-section and the defect morphology.Herein,we propose an optical far-field inspection method based on the form-birefringence scattering imaging of the defective nanostructure,which can identify and classify various defects without requiring optical super-resolution.The technique is built upon the principle of breaking the optical form birefringence of the original periodic nanostructures by the defect perturbation under the anisotropic illumination modes,such as the orthogonally polarized plane waves,then combined with the high-order difference of far-field images.We validated the feasibility and effectiveness of the proposed method in detecting deep subwavelength defects through rigid vector imaging modeling and optical detection experiments of various defective nanostructures based on polarization microscopy.On this basis,an intelligent classification algorithm for typical patterned defects based on a dual-channel AlexNet neural network has been proposed,stabilizing the classification accuracy ofλ/16-sized defects with highly similar features at more than 90%.The strong classification capability of the two-channel network on typical patterned defects can be attributed to the high-order difference image and its transverse gradient being used as the network’s input,which highlights the polarization modulation difference between different patterned defects more significantly than conventional bright-field microscopy results.This work will provide a new but easy-to-operate method for detecting and classifying deep-subwavelength defects in patterned wafers or photomasks,which thus endows current online inspection equipment with more missions in advanced IC manufacturing.
基金supported by the National Natural Science Foundation of China(Nos.22276117 and 22076108)the Science and Technology Innovation Talent Team Project of Shanxi Province(No.202204051002024).
文摘Phenanthrene(Phe)is one of the common polycyclic aromatic hydrocarbons in the environment,and recent studies show that it can cause cardiac developmental toxicity and immunotoxicity.However,it is still unknown whether it can affect the hematopoietic development in aquatic organisms.To address this question,zebrafish(Danio rerio)were chronically exposed to Phe at different concentrations.We found that Phe caused structural damage to the renal tubules in the kidney,induced malformed erythrocytes in peripheral blood,and decreased the proportion of myeloid cells in adult zebrafish,suggesting possible negative impacts that Phe posed to hematopoietic development.Then,using in situ hybridization technology,we found that Phe decreased the expression of primitive hematopoietic marker genes,specifically gata1 and pu.1,accompanied by an obstruction of primitive erythrocyte circulation.Furthermore,Phe impaired definitive hematopoiesis,increased aberrations of the transient hematopoietic site(PBI),and reduced the generation of hematopoietic stem cells,ultimately influencing the number of erythrocytes and myeloid cells.The findings suggested that Phe could induce hematopoietic toxicity in zebrafish embryos and pose unknown ecological risks.
基金financially supported by National Key R&D Program of China(2021YFB3500702)National Natural Science Foundation of China(Nos.21677010 and 51808037)Special fund of Beijing Key Laboratory of Indoor Air Quality Evaluation and Control(No.BZ0344KF21-04).
文摘With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective solutions.Catalysis,being one of the hallmarks of modern industry,offers a promising avenue for researchers.However,the question of how to significantly enhance the performance of catalysts has gradually drawn the attention of scholars.Defect engineering,a commonly employed and effective approach to improve catalyst activity,has become a significant research focus in the catalysis field in recent years.Nonmetal vacancies have received extensive attention due to their simple form.Consequently,exploration of metal vacancies has remained stagnant for a considerable period,resulting in a scarcity of comprehensive reviews on this topic.Therefore,based on the latest research findings,this paper summarizes and consolidates the construction strategies for metal vacancies,characterization techniques,and their roles in typical energy and environmental catalytic reactions.Additionally,it outlines potential challenges in the future,aiming to provide valuable references for researchers interested in investigating metal vacancies.
基金Institute of Technology Research Fund Program for Young Scholars21C Innovation Laboratory Contemporary Amperex Technology Co.,Limited,Ninde, 352100, China (21C–OP-202314)。
文摘Lithium-sulfur (Li-S) batteries have gained great attention due to the high theoretical energy density and low cost,yet their further commercialization has been obstructed by the notorious shuttle effect and sluggish redox dynamics.Herein,we supply a strategy to optimize the electron structure of Ni_(2)P by concurrently introducing B-doped atoms and P vacancies in Ni_(2)P (Vp-B-Ni_(2)P),thereby enhancing the bidirectional sulfur conversion.The study indicates that the simultaneous introduction of B-doped atoms and P vacancies in Ni_(2)P causes the redistribution of electron around Ni atoms,bringing about the upward shift of d-band center of Ni atoms and effective d-p orbital hybridization between Ni atoms and sulfur species,thus strengthening the chemical anchoring for lithium polysulfides (LiPSs) as well as expediting the bidirectional conversion kinetics of sulfur species.Meanwhile,theoretical calculations reveal that the incorporation of B-doped atoms and P vacancies in Ni_(2)P selectively promotes Li2S dissolution and nucleation processes.Thus,the Li-S batteries with Vp-B-Ni_(2)P-separators present outstanding rate ability of 777 m A h g^(-1)at 5 C and high areal capacity of 8.03 mA h cm^(-2)under E/S of 5μL mg^(-1)and sulfur loading of 7.20 mg cm^(-2).This work elucidates that introducing heteroatom and vacancy in metal phosphide collaboratively regulates the electron structure to accelerate bidirectional sulfur conversion.
基金supported by the National Natural Science Foundation of China(Nos.82160419 and 82302772)Guizhou Basic Research Project(No.ZK[2023]General 201)。
文摘As the global population ages,osteoporotic bone fractures leading to bone defects are increasingly becoming a significant challenge in the field of public health.Treating this disease faces many challenges,especially in the context of an imbalance between osteoblast and osteoclast activities.Therefore,the development of new biomaterials has become the key.This article reviews various design strategies and their advantages and disadvantages for biomaterials aimed at osteoporotic bone defects.Overall,current research progress indicates that innovative design,functionalization,and targeting of materials can significantly enhance bone regeneration under osteoporotic conditions.By comprehensively considering biocompatibility,mechanical properties,and bioactivity,these biomaterials can be further optimized,offering a range of choices and strategies for the repair of osteoporotic bone defects.
基金supported by Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX24_4084).
文摘To solve the problem of low detection accuracy for complex weld defects,the paper proposes a weld defects detection method based on improved YOLOv5s.To enhance the ability to focus on key information in feature maps,the scSE attention mechanism is intro-duced into the backbone network of YOLOv5s.A Fusion-Block module and additional layers are added to the neck network of YOLOv5s to improve the effect of feature fusion,which is to meet the needs of complex object detection.To reduce the computation-al complexity of the model,the C3Ghost module is used to replace the CSP2_1 module in the neck network of YOLOv5s.The scSE-ASFF module is constructed and inserted between the neck network and the prediction end,which is to realize the fusion of features between the different layers.To address the issue of imbalanced sample quality in the dataset and improve the regression speed and accuracy of the loss function,the CIoU loss function in the YOLOv5s model is replaced with the Focal-EIoU loss function.Finally,ex-periments are conducted based on the collected weld defect dataset to verify the feasibility of the improved YOLOv5s for weld defects detection.The experimental results show that the precision and mAP of the improved YOLOv5s in detecting complex weld defects are as high as 83.4%and 76.1%,respectively,which are 2.5%and 7.6%higher than the traditional YOLOv5s model.The proposed weld defects detection method based on the improved YOLOv5s in this paper can effectively solve the problem of low weld defects detection accuracy.
基金supported by the Applied Basic Research Program of Yunnan Province(202101BE070001-032)Yunnan Major Scientific and Technological Projects(No.202202AG050001).
文摘The conversion of urea-containing wastewater into clean hydrogen energy has gained increasing attention.However,challenges remain,particularly with sluggish catalytic kinetics and limited long-term stability of urea oxidation reaction(UOR).Herein,we report the loosely porous CoOOH nano-architecture(CoOOH LPNAs)with hydrophilic surface and abundant oxygen vacancies(Ov)on carbon fiber paper(CFP)by electrochemical reconstruction of the CoP nanoneedles precursor.The resulting three-dimensional electrode exhibited an impressively low potential of 1.38 V at 1000 mA·cm^(−2) and excellent durability for UOR.Furthermore,when tested in an anion exchange membrane(AEM)electrolyzer,it required only 1.53 V at 1000 mA·cm^(−2) for industrial urea-assisted water splitting and operated stably for 100 h without degrada-tion.Experimental and theoretical investigations revealed that rich oxygen vacancies effectively modulate the electronic structure of the CoOOH while creating unique Co3-triangle sites with Co atoms close together.As a result,the adsorption and desorption processes of reactants and intermediates in UOR could be finely tuned,thereby significantly reducing ther-modynamic barriers.Additionally,the superhydrophilic self-supported nanoarray structure facilitated rapid gas bubble release,improving the overall efficiency of the reaction and preventing potential catalyst detachment caused by bubble accumulation,thereby improving both catalytic activity and stability at high current densities.
基金National Natural Science Foundation of China(52201054,52175368)National Science and Technology Major Projects(J2019-VI-0018-0133)+2 种基金Liaoning Provincial Science and Technology Program(2023-BS-019,2023-MS-020)National Key R&D Program of China(2021YFB3700401)Key Specialized Research and Development Break-Through-Unveiling and Commanding the Special Project Program in Liaoning Province(2021JH15)。
文摘The impact of casting defects on the weldability of K4951 superalloy was investigated using tungsten inert gas(TIG)welding.The as-cast K4951 superalloy samples with prefabricated U-shaped grooves of varying depths and widths were TIG welded,and the microstructures,cracks morphology,and precipitated phases were analyzed using optical microscope,scanning electron microscope,transmission electron microscope,and energy dispersive X-ray spectrometer.The results reveal that the dimensions of casting defects significantly affect the weldability of K4951.Deep defects(greater than 2 mm)lead to rapid crack propagation,while wider defects can moderate the propagation process of cracks.Elemental segregation and the formation of precipitated phases,such as MC carbides,are observed in the fusion zone,contributing to welding cracks.An optimal groove aspect ratio(depth-to-width)between 0.2 and 0.5 minimizes crack formation tendency and enhances tensile strength,resulting in a mixed brittle-ductile fracture mode of joint after high-temperature tensile testing.
基金supported by a Research Grant of Pukyong National University(2023)。
文摘Achieving high-quality perovskite films without surface defects is regarded as a crucial target for the development of durable high-performance perovskite solar cells.Additive engineering is commonly employed to simultaneously control the growth of perovskite crystals and passivate defects.Here,4-(trifluoromethyl)benzoic anhydride(4-TBA)composed of benzene rings functionalized with carbonyl and trifluoromethyl groups was used as an example additive to study the characteristics of additives used for producing high-quality perovskites and controlling their surface properties.The interaction between4-TBA and perovskite precursor materials was investigated using density functional theory(DFT)simulations.The electron-rich carbonyl group efficiently passivated the under-coordinated lead-ion defects.Additionally,hydrogen bonding between trifluoromethyl and organic cations prevents the generation of cation vacancies.Because of its intrinsic hydrophobicity,the trifluoromethyl group simultaneously improves the moisture and heat stability of the film.4-TBA serves as a universal modifier for various perovskite compositions.The power conversion efficiency(PCE)of inverted perovskite solar cells(PSCs)based on methylammonium(MA)with 4-TBA was improved from 16.15%to 19.28%.Similarly,the PCE of inverted PSCs based on a cesium formamidinium MA(CsFAMA)perovskite film increased from20.72%to 23.58%,upon addition of 4-TBA.Furthermore,the moisture and thermal stability of 4-TBAtreated films and devices was significantly enhanced,along with prolonged device performance.Our work provides guidance on selecting the structure and functional groups that are essential for surface defect passivation and the production of high-quality perovskites.
文摘Directional design of efficient catalysts for volatile organic compounds degradation remains a complex,yet effective and challenging process.Herein,oxygen-rich vacancy Co_(3)O_(4)-anchored Pt catalysts were prepared through atom-trapping strategy and relevant vacancy defect inductive effect was proposed.The 0.6Pt/VO-Co_(3)O_(4)catalyst presented a reaction rate value of 32.2×10^(-5)mol·g_(cat)^(-1)·s^(-1)at 160℃for catalytic propane total oxidation,which was nearly 5 times the reaction rate of Co_(3)O_(4)(6.7×10^(-5)mol·g_(cat)^(-1)·s^(-1)).Also,it exhibited excellent water-resistance and catalytic stability.The Pt atoms were stabilized on the Co_(3)O_(4)surface by vacancy defects to improve dispersion.Meanwhile,the vacancy defect inductive effect induced stronger electron interaction between Pt and Co_(3)O_(4)on the surface,thus promote the redox ability at low-temperature.The mobility and oxygen-activating ability of surface lattice oxygen were also strengthened by the vacancy defect inductive effect.This facilitated the generation of more surface-active oxygen species for the cleavage of C-H bond and the deep oxidation of intermediate species.Overall,this study proposed a novel concept the fabrication of highly efficient catalysts for the purpose of catalytic oxidation.
基金supported by the National Key Research and Development Program of China(No.2022YFA1602700 and 2022YFB2502104)the National Natural Science Foundation of China(22375089)the Key Research and Development Program of Jiangsu Provincial Department of Science and Technology of China(BE2022332).
文摘Electrocatalyst activity and stability demonstrate a“seesaw”relationship.Introducing vacancies(Vo)enhances the activity by improving reactant affinity and increasing accessible active sites.However,deficient or excessive Vo reduces polysulfide adsorption and lowers catalytic stability.Herein,a novel“heteroatoms synergistic anchoring vacancies”strategy is proposed to address the trade-off between high activity and stability.Phosphorus-doped CoSe_(2)with remained rich selenium vacancies(P-CS-Vo-0.5)was synthesized by producing abundant selenium Vo followed by controlled P atom doping.Atomic-scale microstructure analysis elucidated a dynamic process of surface vacancy generation and the subsequent partial occupation of these vacancies by P atoms.Density functional theory simulations and in situ Raman tests revealed that the Se vacancies provide highly active catalytic sites,accelerating polysulfide conversion,while P incorporation effectively reduces the surface energy of Se vacancies and suppresses their inward migration,enhancing structural robustness.The battery with the optimal P-CS-Vo-0.5 separator delivers an initial discharge capacity of 1306.7 mAh g^(-1)at 0.2C,and maintain 5.04 mAh cm^(-2)at a high sulfur loading(5.7 mg cm^(-2),5.0μL mg^(-1)),achieving 95.1%capacity retention after 80 cycles.This strategy of modifying local atomic environments offers a new route to designing highly active and stable catalysts.
文摘Rail defects can pose significant safety risks in railway operations, raising the need for effective detection methods. Acoustic Emission (AE) technology has shown promise for identifying and monitoring these defects, and this study evaluates an advanced on-vehicle AE detection approach using bone-conduct sensors—a solution to improve upon previous AE methods of using on-rail sensor installations, which required extensive, costly on-rail sensor networks with limited effectiveness. In response to these challenges, the study specifically explored bone-conduct sensors mounted directly on the vehicle rather than rails by evaluating AE signals generated by the interaction between rails and the train’s wheels while in motion. In this research, a prototype detection system was developed and tested through initial trials at the Nevada Railroad Museum using a track with pre-damaged welding defects. Further testing was conducted at the Transportation Technology Center Inc. (rebranded as MxV Rail) in Colorado, where the system’s performance was evaluated across various defect types and train speeds. The results indicated that bone-conduct sensors were insufficient for detecting AE signals when mounted on moving vehicles. These findings highlight the limitations of contact-based methods in real-world applications and indicate the need for exploring improved, non-contact approaches.
基金Funded by the Scientific and Technologial Innovation Programs of Higher Education Institutions in Shanxi (No. 2020L0628)the Taiyuan Institute of Technology Scientific Research Initial Funding (No. 2022KJ072)+2 种基金the Program for the (Reserved) Discipline Leaders of Taiyuan Institute of Technologythe Fundamental Research Funds for the Central Universities (Nos. 2017TS004, 2017TS006, and GK201704005)Supported by HZWTECH for providing computational facilities
文摘In order to explore the effect of vacancy defects on the structural,electronic,magnetic and optical properties of CoS_(2) and FeS_(2),first-principles calculation method was used to investigate the alloys.The calculated results of materials without vacancy are consistent with those reported in the literatures,while the results of materials with vacancy defect were different from those of literatures due to the difference vacancy concentration.The Co vacancy defect hardly changes the half-metallic characteristic of CoS_(2).The Fe vacancy defect changes FeS_(2) from semiconductor to half-metal,and the bottom of the spin-down conduction band changes from the p orbital state of S to the d(t_(2g))orbital state of Fe,while the top of the valence band remains the d orbital d(eg)state of Fe.The half-metallic Co vacancy defects of CoS_(2) and Fe vacancy defects of FeS_(2) are expected to be used in spintronic devices.S vacancy defects make both CoS_(2) and FeS_(2) metallic.Both the Co and S vacancy defects lead to the decrease of the magnetic moment of CoS_(2),while both the Fe and S vacancy defects lead to the obvious magnetic property of FeS_(2).Vacancy defects enhance the absorption coefficient of infrared band and long band of visible light obviously,and produce obvious red shift phenomenon,which is expected to be used in photoelectric devices.
基金The“13th Five-Year Plan”National Science and Technology Major Project,2016ZX05052,Changchao QiThe China National Petroleum Corporation Science and Technology Project,2021DJ6505,Changchao Qi.
文摘The accuracy and reliability of non-destructive testing(NDT)approaches in detecting interior corrosion problems are critical,yet research in this field is limited.This work describes a novel way to monitor the structural integrity of steel gas pipelines that uses advanced numerical modeling techniques to anticipate fracture development and corrosion effects.The objective is to increase pipeline dependability and safety through more precise,real-time health evaluations.Compared to previous approaches,our solution provides higher accuracy in fault detection and quantification,making it ideal for pipeline integritymonitoring in real-world applications.To solve this issue,statistical analysis was conducted on the size and directional distribution features of about 380,000 sets of internal corrosion faults,as well as simulations of erosion and wear patterns on bent pipes.Using real defectmorphologies,we developed a modeling framework for typical interior corrosion flaws.We evaluated and validated the applicability and effectiveness of in-service inspection processes,as well as conducted on-site comparison tests.The results show that(1)the length and width of corrosion defects follow a log-normal distribution,the clock orientation follows a normal distribution,and the peak depth follows a Freundlich EX function distribution pattern;(2)pipeline corrosion defect data can be classified into three classes using the K-means clustering algorithm,allowing rapid and convenient acquisition of typical size and orientation characteristics of internal corrosion defects;(3)the applicability range and boundary conditions of various NDT techniques were verified,establishing comprehensive selection principles for internal corrosion defect detection technology;(4)on-site inspection results showed a 31%The simulation and validation platform for typical interior corrosion issues greatly enhances the accuracy and reliability of detection data.
基金financially supported by the National Key Research and Development Program of China(No.2022YFC3703103)National Natural Science Foundation of China(Nos.22206053,42277427)the Guangzhou Science and Technology Plan Project(No.2024A04J4058)。
文摘Bisphenol A(BPA)has threatened ecological safety and human health due to its endocrine disrupting effect and widely diffused in the environment.Peroxymonosulfate(PMS)based on oxidation technology exhibits good potential for environmental remediation whereas the highly efficient activator needs to be developed.Herein,the Bi OBr(BOB)was synthesized to efficiently activate PMS to remove 95.6%of BPA within 60 min.The observed rate constant of BPA removal in BOB/PMS system is 0.049 min^(-1),which is 60 and 148 times to that of the BOB and PMS processes separately and 129 times to the compared Bi OCl(BOC)/PMS system,respectively.Comparison experiments and analytic methods demonstrate that BOB with a larger content of oxygen vacancies(Ov)can act as the bridge of electron transfer between Bi^(3+)/Bi^(4+)with PMS to enhance the activation ability for PMS,resulting in the production of abundant reactive oxygen species(O_(2)^(·-)and ^(1)O_(2)).Additionally,the breakdown processes of BPA and the toxicity of its byproducts were uncovered,and the potential for actual water treatment was evaluated to confirm the detoxification,efficiency,stability and practical use of the BOB/PMS system for eliminating BPA.This study may widen the application of traditional semiconductors and develop the cost-effective PMS activation methods for environmental remediation.
文摘Correction to:Nano-Micro Lett.(2025)17:24 https://doi.org/10.1007/s40820-024-01515-0 Following publication of the original article[1],the authors reported the author list needed to be updated because the last three author names were duplicated.The correct author list has been provided in this Correction.The original article[1]has been corrected.
