The reliable operation of power grid secondary equipment is an important guarantee for the safety and stability of the power system.However,various defects could be produced in the secondary equipment during longtermo...The reliable operation of power grid secondary equipment is an important guarantee for the safety and stability of the power system.However,various defects could be produced in the secondary equipment during longtermoperation.The complex relationship between the defect phenomenon andmulti-layer causes and the probabilistic influence of secondary equipment cannot be described through knowledge extraction and fusion technology by existing methods,which limits the real-time and accuracy of defect identification.Therefore,a defect recognition method based on the Bayesian network and knowledge graph fusion is proposed.The defect data of secondary equipment is transformed into the structured knowledge graph through knowledge extraction and fusion technology.The knowledge graph of power grid secondary equipment is mapped to the Bayesian network framework,combined with historical defect data,and introduced Noisy-OR nodes.The prior and conditional probabilities of the Bayesian network are then reasonably assigned to build a model that reflects the probability dependence between defect phenomena and potential causes in power grid secondary equipment.Defect identification of power grid secondary equipment is achieved by defect subgraph search based on the knowledge graph,and defect inference based on the Bayesian network.Practical application cases prove this method’s effectiveness in identifying secondary equipment defect causes,improving identification accuracy and efficiency.展开更多
Vacancy defects,as fundamental disruptions in metallic lattices,play an important role in shaping the mechanical and electronic properties of aluminum crystals.However,the influence of vacancy position under coupled t...Vacancy defects,as fundamental disruptions in metallic lattices,play an important role in shaping the mechanical and electronic properties of aluminum crystals.However,the influence of vacancy position under coupled thermomechanical fields remains insufficiently understood.In this study,transmission and scanning electron microscopy were employed to observe dislocation structures and grain boundary heterogeneities in processed aluminum alloys,suggesting stress concentrations and microstructural inhomogeneities associated with vacancy accumulation.To complement these observations,first-principles calculations and molecular dynamics simulations were conducted for seven single-vacancy configurations in face-centered cubic aluminum.The stress response,total energy,density of states(DOS),and differential charge density were examined under varying compressive strain(ε=0–0.1)and temperature(0–600 K).The results indicate that face-centered vacancies tend to reduce mechanical strength and perturb electronic states near the Fermi level,whereas corner and edge vacancies appear to have weaker effects.Elevated temperatures may partially restore electronic uniformity through thermal excitation.Overall,these findings suggest that vacancy position exerts a critical but position-dependent influence on coupled structure-property relationships,offering theoretical insights and preliminary experimental support for defect-engineered aluminum alloy design.展开更多
To address the challenges of high-precision optical surface defect detection,we propose a novel design for a wide-field and broadband light field camera in this work.The proposed system can achieve a 50°field of ...To address the challenges of high-precision optical surface defect detection,we propose a novel design for a wide-field and broadband light field camera in this work.The proposed system can achieve a 50°field of view and operates at both visible and near-infrared wavelengths.Using the principles of light field imaging,the proposed design enables 3D reconstruction of optical surfaces,thus enabling vertical surface height measurements with enhanced accuracy.Using Zemax-based simulations,we evaluate the system’s modulation transfer function,its optical aberrations,and its tolerance to shape variations through Zernike coefficient adjustments.The results demonstrate that this camera can achieve the required spatial resolution while also maintaining high imaging quality and thus offers a promising solution for advanced optical surface defect inspection.展开更多
In printed circuit board(PCB)manufacturing,surface defects can significantly affect product quality.To address the performance degradation,high false detection rates,and missed detections caused by complex backgrounds...In printed circuit board(PCB)manufacturing,surface defects can significantly affect product quality.To address the performance degradation,high false detection rates,and missed detections caused by complex backgrounds in current intelligent inspection algorithms,this paper proposes CG-YOLOv8,a lightweight and improved model based on YOLOv8n for PCB surface defect detection.The proposed method optimizes the network architecture and compresses parameters to reduce model complexity while maintaining high detection accuracy,thereby enhancing the capability of identifying diverse defects under complex conditions.Specifically,a cascaded multi-receptive field(CMRF)module is adopted to replace the SPPF module in the backbone to improve feature perception,and an inverted residual mobile block(IRMB)is integrated into the C2f module to further enhance performance.Additionally,conventional convolution layers are replaced with GSConv to reduce computational cost,and a lightweight Convolutional Block Attention Module based Convolution(CBAMConv)module is introduced after Grouped Spatial Convolution(GSConv)to preserve accuracy through attention mechanisms.The detection head is also optimized by removing medium and large-scale detection layers,thereby enhancing the model’s ability to detect small-scale defects and further reducing complexity.Experimental results show that,compared to the original YOLOv8n,the proposed CG-YOLOv8 reduces parameter count by 53.9%,improves mAP@0.5 by 2.2%,and increases precision and recall by 2.0%and 1.8%,respectively.These improvements demonstrate that CG-YOLOv8 offers an efficient and lightweight solution for PCB surface defect detection.展开更多
In order to investigate the effect of die wall thickness on morphologies of defect band,a stepped mold with a wall thickness of 5 mm,4 mm,3 mm,2 mm,and 1 mm was designed to carry out high pressure die casting experime...In order to investigate the effect of die wall thickness on morphologies of defect band,a stepped mold with a wall thickness of 5 mm,4 mm,3 mm,2 mm,and 1 mm was designed to carry out high pressure die casting experiments with AlSi10 MgMn alloy.For castings with wall thickness of 2-4 mm,the ratio of the mean defect band width(w)and mean grain size(d)in the defect band(w/d)ranges 7-18,while it increases to 24.47 for the 5 mm-thick casting.This difference is related with the filling speed and the distribution of externally solidified crystals(ESCs).The mold flow analysis indicates that the filling speed decreases from 25.41 m·s^(-1)to 11.07 m·s^(-1)when wall thickness increases from 2 mm to 5 mm.Due to the decreasing filling speed along the wall thickness,ESCs gradually diffuse from the center to the defect band,which keep the shear strength in the defect band at a high-level during filling.Meanwhile,the shear strength generated during the filling also decreases as the shear rate drops.Finally,the defect bands in the 5 mm-thick region become widen and indistinct,and the porosity is as high as 5.25%.展开更多
Photosynthesis is a promising method for H_(2)O_(2)production,but its application in pure water is limited by slow oxidation kinetics and rapid photocarrier recombination of photocatalysts.Herein,a novel defective car...Photosynthesis is a promising method for H_(2)O_(2)production,but its application in pure water is limited by slow oxidation kinetics and rapid photocarrier recombination of photocatalysts.Herein,a novel defective carbon nitride photocatalyst(D-C3-xN4)containing the C vacancies and the frustrated Lewis pairs(B and N of cyano group)is designed for H_(2)O_(2)photosynthesis,and the role of C vacancies on the electron transfer mechanism during photocatalysis is systematically investigated.The D-C_(3-x)N_(4) exhibits a H_(2)O_(2)production rate of 140.1μmol·g^(-1)·h^(-1) in pure water,which is 87.6 times that of C_(3)N_(4).Such superior performance for H_(2)O_(2)photosynthesis is found to arise from the C vacancies and frustrated Lewis pairs(FLPs).The C vacancies have strong electron-trapping ability,which greatly enhances the separation of photocarriers.The C vacancies can also effectively reduce O_(2)to*OOH via a proton-coupled process,which significantly accelerates the O_(2)reduction kinetics.Meanwhile,the FLPs show an outstanding catalytic activity for H_(2)O oxidation.This study not only provides a new structure for highly active photocatalysts,but also deepens the understanding of the electron transfer mechanism of photocatalysts with trapped sites.展开更多
While thermal air exfoliation is widely used to prepare graphitic carbon nitride(g-C_(3)N_(4))nanosheets,the effects of calcination conditions and atmosphere on their electronic structure and photocatalytic CO_(2)redu...While thermal air exfoliation is widely used to prepare graphitic carbon nitride(g-C_(3)N_(4))nanosheets,the effects of calcination conditions and atmosphere on their electronic structure and photocatalytic CO_(2)reduction reaction(CO_(2)RR)performance remain systematically unexplored.We prepared g-C_(3)N_(4)nanosheets with varying thickness and defects by controlling exfoliation parameters.The obtained nanosheets calcined longest in air exhibited highest CO_(2)RR activity,twice that of bulk g-C_(3)N_(4).The comprehensive analysis of structural characterizations indicates the thickness of g-C_(3)N_(4)nanosheets became thinner,and the defects increased as the calcination time increased.The N vacancies(N_(v))and O-doping caused by N_(2) and O_(2)from air,respectively,enable valence band elevation(N_(v))and conduction band depression(O-doping)that collectively redistribute the electronic structure.Nitrogen/oxygen dual-defects generated impurity levels,reduced the work function and band gap of g-C_(3)N_(4)nanosheets,and served as shallow traps for photogenerated e^(-).The results of in-situ spectroscopy indicate these increased effective e^(-)are enriched around of N atoms to react with the adsorbed CO_(2).During the CO_(2)reduction process,the N_(v) promoted the formation of*COOH,and this dual-defect co-promoted the*CO desorption,resulting in the improved CO_(2)RR activity.These results comprehensively analyze the regulatory effect of thermal air calcination on the electronic structure of g-C_(3)N_(4),providing valuable insights for designing g-C_(3)N_(4)nanosheets based photocatalysts for CO_(2)RR.展开更多
The volume defects in pure pyrite and quartz from a classical Cu-Pb-Zn-Fe sulfide deposit were investigated.The results indicate that a large number of volume defects exist in natural pyrite and quartz.The volume defe...The volume defects in pure pyrite and quartz from a classical Cu-Pb-Zn-Fe sulfide deposit were investigated.The results indicate that a large number of volume defects exist in natural pyrite and quartz.The volume defects assume a variety of shapes,including long strips,oval shapes and irregular shapes,with sizes ranging from a few microns to dozens of microns.These volume defects are rich in metallogenic elements as a result of the capture of metallogenic and mineralizing fluid during the defect-forming process.The volume defects are fractured during the grinding process,and their chemical components are released into the solution,as confirmed by the abundant presence of various metal and non-metal components in the cleaning water and EDS results.Under the experimental conditions of 10 g pyrite or quartz with grinding fineness of d90=37 μm,which was cleaned in 40 m L of pure deionised water under an inert atmosphere,the total average concentrations of Cu,Pb,Zn,Fe,Ca,Mg and Cl-in the aqueous solution are 32.09×10^-7,16.51×10^-7,19.45×10^-7,516.52×10^-7,129.50×10^-7,35.30×10^-7 and 433.80×10^-7 mol/L,respectively,for pyrite and 19.20×10^-7,8.88×10^-7,8.31×10^-7,82.71×10^-7,16.21×10^-7,4.28×10^-7 and 731.26×10^-7 mol/L,respectively,for quartz.These values are significantly greater than those from the experimental non-oxidative dissolution of the pyrite or quartz,respectively.Therefore,the metallogenic fluid in volume defects of mineral crystal is concluded to represent the dominant contribution to the solution chemistry of sulfide flotation pulp.The present investigation will help to deeply understand the flotation theory of sulfide minerals.展开更多
A newly developed pure rolling fatigue test rig with three contact points is used to test the rolling contact fatigue properties of silicon nitride ceramic balls. Ball surfaces are examined after failure with optical ...A newly developed pure rolling fatigue test rig with three contact points is used to test the rolling contact fatigue properties of silicon nitride ceramic balls. Ball surfaces are examined after failure with optical microscopy and scanning electron microscopy. The failure cause, fatigue phenomenon and mechanics are analyzed. The research shows that subsurface cracks play a dominant role in the formation of spalling failure. These cracks originated from volume defects of the material and propagate, to form elliptical fatigue spalls under the action of principal tensile stresses. The principal tensile stress increases with increasing contact load, causing spall formation and reduction of rolling contact life. The greater the principal tensile stress is, the more severe the peeling of near surface is. Under the same condition, the closer volume defects are to the surface, the more likely failure occurs, the shorter the rolling contact life is.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
Background: Real-time three-dimensional echocardiography (RT-3DE) could obtain ventricular volume andejection fraction rapidly and non-invasively without relying on ventricular morphology. This study aims to useRT-3DE...Background: Real-time three-dimensional echocardiography (RT-3DE) could obtain ventricular volume andejection fraction rapidly and non-invasively without relying on ventricular morphology. This study aims to useRT-3DE to evaluate the changes in biventricular volume and systolic function in children with ventricular septaldefect (VSD) and moderate to severe pulmonary hypertension (PH) before surgery. Methods: In this study18 children with VSD and moderate to severe PH (VSD + PH Group) and 18 healthy children of the sameage (Control Group) were recruited. Biventricular volume and systolic function were evaluated by RT-3DE.The measurements included: left and right ventricular volume indexed to body surface area (BSA), stroke volume(SV) indexed to BSA, and ejection fraction (EF). Results: The results showed left and right ventricular volumeindexed to BSA and SV indexed to BSA were significantly increased in VSD + PH Group (VSD + PH Groupvs. Control Group), LVEDV/BSA (ml/m2): 48.67 ± 21.46 vs. 25.59 ± 6.96, RVEDV/BSA (ml/m2): 55.98 ±15.35 vs. 27.69 ± 4.37, LVSV/BSA (ml/m2): 24.08 ± 9.30 vs. 15.14 ± 4.29, RVSV/BSA (ml/m2): 26.02 ± 8.87 vs.14.11 ± 2.89, (P < 0.05). While for EF in VSD + PH Group decreased (VSD + PH Group vs. Control Group),LVEF: 50.93 ± 7.50% vs. 59.38 ± 7.24%, RVEF: 45.84 ± 7.71% vs. 51.05 ± 6.90% (P < 0.05). Conclusion: Inchildren with VSD and moderate to severe PH, increased biventricular volume and decreased systolic functionwere observed with RT-3DE, but biventricular systolic function remained within acceptable limits. The childrenin this study recovered well after surgery without serious perioperative complications, suggesting that biventricularsystolic function may help facilitate the surgical decision-making process in children with VSD and moderate-toseverePH.展开更多
Background:Closure of an atrial septal defect(ASD)reduces right-side heart volumes by abolishing shunting with simultaneous improvement of the left ventricle(LV)filling and functions due to ventricular interdependence,...Background:Closure of an atrial septal defect(ASD)reduces right-side heart volumes by abolishing shunting with simultaneous improvement of the left ventricle(LV)filling and functions due to ventricular interdependence,thereby improving symptoms.Furthermore,studies conducted on atrial volume changes after ASD closure are limited.Cardiac magnetic resonance(CMR)is considered as the gold standard method for measuring cardiac volume and mass.Objective:We aimed to study the effect of transcatheter and surgical closure of secundum ASD on cardiac volumes and systolic functions as well as the fate of tricuspid regurgitation(TR),using CMR analysis.Methods:We prospectively enrolled 30 adult patients with isolated secundum ASD who were referred to ASD closure.CMR evaluation of cardiac chambers indexed volumes,systolic function,myocardial mass index,and tricuspid regurgitant fraction were done at before and 6 months after closure.Results:RV volumes decreased in both groups when compared to baseline(p-value 0.001),the device group had more reduction in volumes and more improvement in RV function after closure(p-value 0.001)when compared to the surgical arm.The changes in the RV mass index were insignificant between both groups(p-value 0.31).Functional TR improved to the same extent in both groups.Left ventricular end diastolic volume index(LVEDVI)and LV mass index increased sig-nificantly in both groups when compared to baseline in both groups but with no difference between groups p-value 0.01),left ventricular end systolic volume index(LVESVI)changes were insignificant.LV systolic function improved in patients who underwent device closure only(63.53±3.85 vs.67.13±4.34,p-value 0.01).There was a significant reduction in right atrial(RA)volumes and an insignificant decrease in left atrial(LA)volumes,with no difference between groups.Conclusion:Transcatheter and surgical secundum ASD closure resulted in volumetric changes in some cardiac chambers with better improvement in bi-ventricular systolic function in the transcatheter arm and no difference in the TR reduction between the two groups at 6 months follow-up by CMR.展开更多
Micro-sieves have been widely used in medical treatment,quarantine,environment,agriculture,pharmacy and food processing.However,the manufacturing and yield improvement have been difficult due to multiple challenges,su...Micro-sieves have been widely used in medical treatment,quarantine,environment,agriculture,pharmacy and food processing.However,the manufacturing and yield improvement have been difficult due to multiple challenges,such as the sieve unit release defect,cracking,and KOH corrosion.In this paper,we report process details and discuss technical difficulties which are usually the root-causes for process failures,and demonstrate a reliable and high yield production of SiNx micro-sieves processed with our novel method,which is also compatible with high volume manufacturing.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
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
Infectious bone defects represent a substantial challenge in clinical practice,necessitating the deployment of advanced therapeutic strategies.This study presents a treatment modality that merges a mild photothermal t...Infectious bone defects represent a substantial challenge in clinical practice,necessitating the deployment of advanced therapeutic strategies.This study presents a treatment modality that merges a mild photothermal therapy hydrogel with a pulsed drug delivery mechanism.The system is predicated on a hydrogel matrix that is thermally responsive,characteristic of bone defect sites,facilitating controlled and site-specific drug release.The cornerstone of this system is the incorporation of mild photothermal nanoparticles,which are activated within the temperature range of 40–43°C,thereby enhancing the precision and efficacy of drug delivery.Our findings demonstrate that the photothermal response significantly augments the localized delivery of therapeutic agents,mitigating systemic side effects and bolstering efficacy at the defect site.The synchronized pulsed release,cooperated with mild photothermal therapy,effectively addresses infection control,and promotes bone regeneration.This approach signifies a considerable advancement in the management of infectious bone defects,offering an effective and patient-centric alternative to traditional methods.Our research endeavors to extend its applicability to a wider spectrum of tissue regeneration scenarios,underscoring its transformative potential in the realm of regenerative medicine.展开更多
The rapid progress in the construction of heavy-haul and high-speed railways has led to a surge in rail defects and unforeseen failures.Addressing this issue necessitates the implementation of more sophisticated rail ...The rapid progress in the construction of heavy-haul and high-speed railways has led to a surge in rail defects and unforeseen failures.Addressing this issue necessitates the implementation of more sophisticated rail inspection methods,specifically involving real-time,precise detection,and assessment of rail defects.Current applications fail to address the evolving requirements,prompting the need for advancements.This paper provides a summary of various types of rail defects and outlines both traditional and innovative non-destructive inspection techniques,examining their fundamental features,benefits,drawbacks,and practical suitability for railway track inspection.It also explores potential enhancements to equipment and software.The comprehensive review draws upon pertinent international research and review papers.Furthermore,the paper introduces a fusion of inspection methods aimed at enhancing the overall reliability of defect detection.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
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
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
基金supported by the State Grid Southwest Branch Project“Research on Defect Diagnosis and Early Warning Technology of Relay Protection and Safety Automation Devices Based on Multi-Source Heterogeneous Defect Data”.
文摘The reliable operation of power grid secondary equipment is an important guarantee for the safety and stability of the power system.However,various defects could be produced in the secondary equipment during longtermoperation.The complex relationship between the defect phenomenon andmulti-layer causes and the probabilistic influence of secondary equipment cannot be described through knowledge extraction and fusion technology by existing methods,which limits the real-time and accuracy of defect identification.Therefore,a defect recognition method based on the Bayesian network and knowledge graph fusion is proposed.The defect data of secondary equipment is transformed into the structured knowledge graph through knowledge extraction and fusion technology.The knowledge graph of power grid secondary equipment is mapped to the Bayesian network framework,combined with historical defect data,and introduced Noisy-OR nodes.The prior and conditional probabilities of the Bayesian network are then reasonably assigned to build a model that reflects the probability dependence between defect phenomena and potential causes in power grid secondary equipment.Defect identification of power grid secondary equipment is achieved by defect subgraph search based on the knowledge graph,and defect inference based on the Bayesian network.Practical application cases prove this method’s effectiveness in identifying secondary equipment defect causes,improving identification accuracy and efficiency.
基金supported by the Research Project on Strengthening the Construction of an Important Ecological Security Barrier in Northern China by Higher Education Institutions in the Inner Mongolia Autonomous Region(STAQZX202313)the Inner Mongolia Autonomous Region Education Science‘14th Five-Year Plan’2024 Annual Research Project(NGJGH2024635).
文摘Vacancy defects,as fundamental disruptions in metallic lattices,play an important role in shaping the mechanical and electronic properties of aluminum crystals.However,the influence of vacancy position under coupled thermomechanical fields remains insufficiently understood.In this study,transmission and scanning electron microscopy were employed to observe dislocation structures and grain boundary heterogeneities in processed aluminum alloys,suggesting stress concentrations and microstructural inhomogeneities associated with vacancy accumulation.To complement these observations,first-principles calculations and molecular dynamics simulations were conducted for seven single-vacancy configurations in face-centered cubic aluminum.The stress response,total energy,density of states(DOS),and differential charge density were examined under varying compressive strain(ε=0–0.1)and temperature(0–600 K).The results indicate that face-centered vacancies tend to reduce mechanical strength and perturb electronic states near the Fermi level,whereas corner and edge vacancies appear to have weaker effects.Elevated temperatures may partially restore electronic uniformity through thermal excitation.Overall,these findings suggest that vacancy position exerts a critical but position-dependent influence on coupled structure-property relationships,offering theoretical insights and preliminary experimental support for defect-engineered aluminum alloy design.
基金supported by the Jilin Science and Technology Development Plan(20240101029JJ)the following study:synchronized high-speed detection of surface shape and defects in the grinding stage of complex surfaces(KLMSZZ202305)+3 种基金for the high-precision wide dynamic large aperture optical inspection system for fine astronomical observation by the National Major Research Instrument Development Project(62127901)for ultrasmooth manufacturing technology of large diameter complex curved surface by the National Key R&D Program(2022YFB3403405)for research on the key technology of rapid synchronous detection of surface shape and subsurface defects in the grinding stage of large diameter complex surfaces by the International Cooperation Project(2025010157)The Key Laboratory of Optical System Advanced Manufacturing Technology,Chinese Academy of Sciences(2022KLOMT02-04)also supported this study.
文摘To address the challenges of high-precision optical surface defect detection,we propose a novel design for a wide-field and broadband light field camera in this work.The proposed system can achieve a 50°field of view and operates at both visible and near-infrared wavelengths.Using the principles of light field imaging,the proposed design enables 3D reconstruction of optical surfaces,thus enabling vertical surface height measurements with enhanced accuracy.Using Zemax-based simulations,we evaluate the system’s modulation transfer function,its optical aberrations,and its tolerance to shape variations through Zernike coefficient adjustments.The results demonstrate that this camera can achieve the required spatial resolution while also maintaining high imaging quality and thus offers a promising solution for advanced optical surface defect inspection.
基金funded by the Joint Funds of the National Natural Science Foundation of China(U2341223)the Beijing Municipal Natural Science Foundation(No.4232067).
文摘In printed circuit board(PCB)manufacturing,surface defects can significantly affect product quality.To address the performance degradation,high false detection rates,and missed detections caused by complex backgrounds in current intelligent inspection algorithms,this paper proposes CG-YOLOv8,a lightweight and improved model based on YOLOv8n for PCB surface defect detection.The proposed method optimizes the network architecture and compresses parameters to reduce model complexity while maintaining high detection accuracy,thereby enhancing the capability of identifying diverse defects under complex conditions.Specifically,a cascaded multi-receptive field(CMRF)module is adopted to replace the SPPF module in the backbone to improve feature perception,and an inverted residual mobile block(IRMB)is integrated into the C2f module to further enhance performance.Additionally,conventional convolution layers are replaced with GSConv to reduce computational cost,and a lightweight Convolutional Block Attention Module based Convolution(CBAMConv)module is introduced after Grouped Spatial Convolution(GSConv)to preserve accuracy through attention mechanisms.The detection head is also optimized by removing medium and large-scale detection layers,thereby enhancing the model’s ability to detect small-scale defects and further reducing complexity.Experimental results show that,compared to the original YOLOv8n,the proposed CG-YOLOv8 reduces parameter count by 53.9%,improves mAP@0.5 by 2.2%,and increases precision and recall by 2.0%and 1.8%,respectively.These improvements demonstrate that CG-YOLOv8 offers an efficient and lightweight solution for PCB surface defect detection.
基金supported by the National Natural Science Foundation of China(No.52474396 and 52175284)the National Key Research and Development Program of China(Grant No.2022YFB3404201)。
文摘In order to investigate the effect of die wall thickness on morphologies of defect band,a stepped mold with a wall thickness of 5 mm,4 mm,3 mm,2 mm,and 1 mm was designed to carry out high pressure die casting experiments with AlSi10 MgMn alloy.For castings with wall thickness of 2-4 mm,the ratio of the mean defect band width(w)and mean grain size(d)in the defect band(w/d)ranges 7-18,while it increases to 24.47 for the 5 mm-thick casting.This difference is related with the filling speed and the distribution of externally solidified crystals(ESCs).The mold flow analysis indicates that the filling speed decreases from 25.41 m·s^(-1)to 11.07 m·s^(-1)when wall thickness increases from 2 mm to 5 mm.Due to the decreasing filling speed along the wall thickness,ESCs gradually diffuse from the center to the defect band,which keep the shear strength in the defect band at a high-level during filling.Meanwhile,the shear strength generated during the filling also decreases as the shear rate drops.Finally,the defect bands in the 5 mm-thick region become widen and indistinct,and the porosity is as high as 5.25%.
基金supported by the Shaanxi Sanqin Scholars Innovation Team,the Science and Technology Project of Yan’an City(No.2023-CYL-193)the Key Science Research Plan of Department of Education in Shaanxi Province(No.23JS070)the Science Research Training Project(No.CLXZ2207).
文摘Photosynthesis is a promising method for H_(2)O_(2)production,but its application in pure water is limited by slow oxidation kinetics and rapid photocarrier recombination of photocatalysts.Herein,a novel defective carbon nitride photocatalyst(D-C3-xN4)containing the C vacancies and the frustrated Lewis pairs(B and N of cyano group)is designed for H_(2)O_(2)photosynthesis,and the role of C vacancies on the electron transfer mechanism during photocatalysis is systematically investigated.The D-C_(3-x)N_(4) exhibits a H_(2)O_(2)production rate of 140.1μmol·g^(-1)·h^(-1) in pure water,which is 87.6 times that of C_(3)N_(4).Such superior performance for H_(2)O_(2)photosynthesis is found to arise from the C vacancies and frustrated Lewis pairs(FLPs).The C vacancies have strong electron-trapping ability,which greatly enhances the separation of photocarriers.The C vacancies can also effectively reduce O_(2)to*OOH via a proton-coupled process,which significantly accelerates the O_(2)reduction kinetics.Meanwhile,the FLPs show an outstanding catalytic activity for H_(2)O oxidation.This study not only provides a new structure for highly active photocatalysts,but also deepens the understanding of the electron transfer mechanism of photocatalysts with trapped sites.
基金supported by the National Natural Science Foundation of China(Nos.62004143 and 22502150)the Key Project of Scientific Research Plan of Hubei Provincial Department of Education(No.D20241501)+5 种基金the China Postdoctoral Science Foundation(No.2024M762505)the Postdoctoral Fellowship Program(Grade C)(No.GZC20250787)the China Postdoctoral Science Foundation-Hubei Joint Support Program(No.2025T032HB)the Scientific Research Fund Project of Wuhan Institute of Technology(Nos.K2024053,K2025102,and 25QD010)the Open Fund of the Guangdong Provincial Key Laboratory of Electronic Functional Materials and Devices(No.EFMD2024006Z)the Innovation Project of Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of Education(No.LCX202404).
文摘While thermal air exfoliation is widely used to prepare graphitic carbon nitride(g-C_(3)N_(4))nanosheets,the effects of calcination conditions and atmosphere on their electronic structure and photocatalytic CO_(2)reduction reaction(CO_(2)RR)performance remain systematically unexplored.We prepared g-C_(3)N_(4)nanosheets with varying thickness and defects by controlling exfoliation parameters.The obtained nanosheets calcined longest in air exhibited highest CO_(2)RR activity,twice that of bulk g-C_(3)N_(4).The comprehensive analysis of structural characterizations indicates the thickness of g-C_(3)N_(4)nanosheets became thinner,and the defects increased as the calcination time increased.The N vacancies(N_(v))and O-doping caused by N_(2) and O_(2)from air,respectively,enable valence band elevation(N_(v))and conduction band depression(O-doping)that collectively redistribute the electronic structure.Nitrogen/oxygen dual-defects generated impurity levels,reduced the work function and band gap of g-C_(3)N_(4)nanosheets,and served as shallow traps for photogenerated e^(-).The results of in-situ spectroscopy indicate these increased effective e^(-)are enriched around of N atoms to react with the adsorbed CO_(2).During the CO_(2)reduction process,the N_(v) promoted the formation of*COOH,and this dual-defect co-promoted the*CO desorption,resulting in the improved CO_(2)RR activity.These results comprehensively analyze the regulatory effect of thermal air calcination on the electronic structure of g-C_(3)N_(4),providing valuable insights for designing g-C_(3)N_(4)nanosheets based photocatalysts for CO_(2)RR.
基金Project(51464029)supported by the National Natural Science Foundation of ChinaProject(2014M562343)supported by the China Postdoctoral Science FoundationProject(KKSY201421110)supported the Scholar Development Project of Yunnan Province,China
文摘The volume defects in pure pyrite and quartz from a classical Cu-Pb-Zn-Fe sulfide deposit were investigated.The results indicate that a large number of volume defects exist in natural pyrite and quartz.The volume defects assume a variety of shapes,including long strips,oval shapes and irregular shapes,with sizes ranging from a few microns to dozens of microns.These volume defects are rich in metallogenic elements as a result of the capture of metallogenic and mineralizing fluid during the defect-forming process.The volume defects are fractured during the grinding process,and their chemical components are released into the solution,as confirmed by the abundant presence of various metal and non-metal components in the cleaning water and EDS results.Under the experimental conditions of 10 g pyrite or quartz with grinding fineness of d90=37 μm,which was cleaned in 40 m L of pure deionised water under an inert atmosphere,the total average concentrations of Cu,Pb,Zn,Fe,Ca,Mg and Cl-in the aqueous solution are 32.09×10^-7,16.51×10^-7,19.45×10^-7,516.52×10^-7,129.50×10^-7,35.30×10^-7 and 433.80×10^-7 mol/L,respectively,for pyrite and 19.20×10^-7,8.88×10^-7,8.31×10^-7,82.71×10^-7,16.21×10^-7,4.28×10^-7 and 731.26×10^-7 mol/L,respectively,for quartz.These values are significantly greater than those from the experimental non-oxidative dissolution of the pyrite or quartz,respectively.Therefore,the metallogenic fluid in volume defects of mineral crystal is concluded to represent the dominant contribution to the solution chemistry of sulfide flotation pulp.The present investigation will help to deeply understand the flotation theory of sulfide minerals.
基金This project is supported by Provincial University Natural Science Fund of Jiangsu, China (No. 05KJB460106)Municipal Science and Technology Development Fund of Shanghai, China (No. 0152nm031)Municipal Natural Science Fund of Nantong, China (No. Z5005).
文摘A newly developed pure rolling fatigue test rig with three contact points is used to test the rolling contact fatigue properties of silicon nitride ceramic balls. Ball surfaces are examined after failure with optical microscopy and scanning electron microscopy. The failure cause, fatigue phenomenon and mechanics are analyzed. The research shows that subsurface cracks play a dominant role in the formation of spalling failure. These cracks originated from volume defects of the material and propagate, to form elliptical fatigue spalls under the action of principal tensile stresses. The principal tensile stress increases with increasing contact load, causing spall formation and reduction of rolling contact life. The greater the principal tensile stress is, the more severe the peeling of near surface is. Under the same condition, the closer volume defects are to the surface, the more likely failure occurs, the shorter the rolling contact life is.
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Wuhan Health and Family Planning Commission Grant/Award(WX16D18).
文摘Background: Real-time three-dimensional echocardiography (RT-3DE) could obtain ventricular volume andejection fraction rapidly and non-invasively without relying on ventricular morphology. This study aims to useRT-3DE to evaluate the changes in biventricular volume and systolic function in children with ventricular septaldefect (VSD) and moderate to severe pulmonary hypertension (PH) before surgery. Methods: In this study18 children with VSD and moderate to severe PH (VSD + PH Group) and 18 healthy children of the sameage (Control Group) were recruited. Biventricular volume and systolic function were evaluated by RT-3DE.The measurements included: left and right ventricular volume indexed to body surface area (BSA), stroke volume(SV) indexed to BSA, and ejection fraction (EF). Results: The results showed left and right ventricular volumeindexed to BSA and SV indexed to BSA were significantly increased in VSD + PH Group (VSD + PH Groupvs. Control Group), LVEDV/BSA (ml/m2): 48.67 ± 21.46 vs. 25.59 ± 6.96, RVEDV/BSA (ml/m2): 55.98 ±15.35 vs. 27.69 ± 4.37, LVSV/BSA (ml/m2): 24.08 ± 9.30 vs. 15.14 ± 4.29, RVSV/BSA (ml/m2): 26.02 ± 8.87 vs.14.11 ± 2.89, (P < 0.05). While for EF in VSD + PH Group decreased (VSD + PH Group vs. Control Group),LVEF: 50.93 ± 7.50% vs. 59.38 ± 7.24%, RVEF: 45.84 ± 7.71% vs. 51.05 ± 6.90% (P < 0.05). Conclusion: Inchildren with VSD and moderate to severe PH, increased biventricular volume and decreased systolic functionwere observed with RT-3DE, but biventricular systolic function remained within acceptable limits. The childrenin this study recovered well after surgery without serious perioperative complications, suggesting that biventricularsystolic function may help facilitate the surgical decision-making process in children with VSD and moderate-toseverePH.
文摘Background:Closure of an atrial septal defect(ASD)reduces right-side heart volumes by abolishing shunting with simultaneous improvement of the left ventricle(LV)filling and functions due to ventricular interdependence,thereby improving symptoms.Furthermore,studies conducted on atrial volume changes after ASD closure are limited.Cardiac magnetic resonance(CMR)is considered as the gold standard method for measuring cardiac volume and mass.Objective:We aimed to study the effect of transcatheter and surgical closure of secundum ASD on cardiac volumes and systolic functions as well as the fate of tricuspid regurgitation(TR),using CMR analysis.Methods:We prospectively enrolled 30 adult patients with isolated secundum ASD who were referred to ASD closure.CMR evaluation of cardiac chambers indexed volumes,systolic function,myocardial mass index,and tricuspid regurgitant fraction were done at before and 6 months after closure.Results:RV volumes decreased in both groups when compared to baseline(p-value 0.001),the device group had more reduction in volumes and more improvement in RV function after closure(p-value 0.001)when compared to the surgical arm.The changes in the RV mass index were insignificant between both groups(p-value 0.31).Functional TR improved to the same extent in both groups.Left ventricular end diastolic volume index(LVEDVI)and LV mass index increased sig-nificantly in both groups when compared to baseline in both groups but with no difference between groups p-value 0.01),left ventricular end systolic volume index(LVESVI)changes were insignificant.LV systolic function improved in patients who underwent device closure only(63.53±3.85 vs.67.13±4.34,p-value 0.01).There was a significant reduction in right atrial(RA)volumes and an insignificant decrease in left atrial(LA)volumes,with no difference between groups.Conclusion:Transcatheter and surgical secundum ASD closure resulted in volumetric changes in some cardiac chambers with better improvement in bi-ventricular systolic function in the transcatheter arm and no difference in the TR reduction between the two groups at 6 months follow-up by CMR.
文摘Micro-sieves have been widely used in medical treatment,quarantine,environment,agriculture,pharmacy and food processing.However,the manufacturing and yield improvement have been difficult due to multiple challenges,such as the sieve unit release defect,cracking,and KOH corrosion.In this paper,we report process details and discuss technical difficulties which are usually the root-causes for process failures,and demonstrate a reliable and high yield production of SiNx micro-sieves processed with our novel method,which is also compatible with high volume manufacturing.
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 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.
基金supported by the National Natural Science Foundation of China(32171354,82222015,82171001)The National Key Research and Development Program of China2023YFC2413600Research Funding from West China School/Hospital of Stomatology,Sichuan University(No.RCDWIS2023-1).
文摘Infectious bone defects represent a substantial challenge in clinical practice,necessitating the deployment of advanced therapeutic strategies.This study presents a treatment modality that merges a mild photothermal therapy hydrogel with a pulsed drug delivery mechanism.The system is predicated on a hydrogel matrix that is thermally responsive,characteristic of bone defect sites,facilitating controlled and site-specific drug release.The cornerstone of this system is the incorporation of mild photothermal nanoparticles,which are activated within the temperature range of 40–43°C,thereby enhancing the precision and efficacy of drug delivery.Our findings demonstrate that the photothermal response significantly augments the localized delivery of therapeutic agents,mitigating systemic side effects and bolstering efficacy at the defect site.The synchronized pulsed release,cooperated with mild photothermal therapy,effectively addresses infection control,and promotes bone regeneration.This approach signifies a considerable advancement in the management of infectious bone defects,offering an effective and patient-centric alternative to traditional methods.Our research endeavors to extend its applicability to a wider spectrum of tissue regeneration scenarios,underscoring its transformative potential in the realm of regenerative medicine.
文摘The rapid progress in the construction of heavy-haul and high-speed railways has led to a surge in rail defects and unforeseen failures.Addressing this issue necessitates the implementation of more sophisticated rail inspection methods,specifically involving real-time,precise detection,and assessment of rail defects.Current applications fail to address the evolving requirements,prompting the need for advancements.This paper provides a summary of various types of rail defects and outlines both traditional and innovative non-destructive inspection techniques,examining their fundamental features,benefits,drawbacks,and practical suitability for railway track inspection.It also explores potential enhancements to equipment and software.The comprehensive review draws upon pertinent international research and review papers.Furthermore,the paper introduces a fusion of inspection methods aimed at enhancing the overall reliability of defect detection.
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.
