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Micro defects formation and dynamic response analysis of steel plate of quasi-cracking area subjected to explosive load
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作者 Zheng-qing Zhou Ze-chen Du +5 位作者 Xiao Wang Hui-ling Jiang Qiang Zhou Yu-long Zhang Yu-zhe Liu Pei-ze Zhang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期580-593,共14页
As the protective component,steel plate had attracted extensive attention because of frequently threats of explosive loads.In this paper,the evolution of microstructure and the mechanism of damage in the quasi-crackin... As the protective component,steel plate had attracted extensive attention because of frequently threats of explosive loads.In this paper,the evolution of microstructure and the mechanism of damage in the quasi-cracking area of steel plate subjected to explosive load were discussed and the relationships between micro defects and dynamic mechanical response were revealed.After the explosion experiment,five observation points were selected equidistant from the quasi-cracking area of the section of the steel plate along the thickness direction,and the characteristics of micro defects at the observation points were analyzed by optical microscope(OM),scanning electron microscope(SEM) and electron backscattered diffraction(EBSD).The observation result shows that many slip bands(SBs) appeared,and the grain orientation changed obviously in the steel plate,the two were the main damage types of micro defects.In addition,cracks,peeling pits,grooves and other lager micro defects were appeared in the lower area of the plate.The stress parameters of the observation points were obtained through an effective numerical model.The mechanism of damage generation and crack propagation in the quasicracking area were clarified by comparing the specific impulse of each observation point with the corresponding micro defects.The result shows that the generation and expansion of micro defects are related to the stress area(i.e.the upper compression area,the neutral plane area,and the lower tension area).The micro defects gather and expand at the grain boundary,and will become macroscopic damage under the continuous action of tensile stress.Besides,the micro defects at the midpoint of the section of the steel plate in the direction away from the explosion center(i.e.the horizontal direction) were also studied.It was found that the specific impulse at these positions were much smaller than that in the thickness direction,the micro defects were only SBs and a few micro cracks,and the those decreased with the increase of the distance from the explosion center. 展开更多
关键词 Explosive load Quasi-cracking area Micro defects Steel plate Dynamic response Numerical simulation
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Static Analysis Techniques for Fixing Software Defects in MPI-Based Parallel Programs
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作者 Norah Abdullah Al-Johany Sanaa Abdullah Sharaf +1 位作者 Fathy Elbouraey Eassa Reem Abdulaziz Alnanih 《Computers, Materials & Continua》 SCIE EI 2024年第5期3139-3173,共35页
The Message Passing Interface (MPI) is a widely accepted standard for parallel computing on distributed memorysystems.However, MPI implementations can contain defects that impact the reliability and performance of par... The Message Passing Interface (MPI) is a widely accepted standard for parallel computing on distributed memorysystems.However, MPI implementations can contain defects that impact the reliability and performance of parallelapplications. Detecting and correcting these defects is crucial, yet there is a lack of published models specificallydesigned for correctingMPI defects. To address this, we propose a model for detecting and correcting MPI defects(DC_MPI), which aims to detect and correct defects in various types of MPI communication, including blockingpoint-to-point (BPTP), nonblocking point-to-point (NBPTP), and collective communication (CC). The defectsaddressed by the DC_MPI model include illegal MPI calls, deadlocks (DL), race conditions (RC), and messagemismatches (MM). To assess the effectiveness of the DC_MPI model, we performed experiments on a datasetconsisting of 40 MPI codes. The results indicate that the model achieved a detection rate of 37 out of 40 codes,resulting in an overall detection accuracy of 92.5%. Additionally, the execution duration of the DC_MPI modelranged from 0.81 to 1.36 s. These findings show that the DC_MPI model is useful in detecting and correctingdefects in MPI implementations, thereby enhancing the reliability and performance of parallel applications. TheDC_MPImodel fills an important research gap and provides a valuable tool for improving the quality ofMPI-basedparallel computing systems. 展开更多
关键词 High-performance computing parallel computing software engineering software defect message passing interface DEADLOCK
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Microscopic defects formation and dynamic mechanical response analysis of Q345 steel plate subjected to explosive load
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作者 Zhengqing Zhou Zechen Du +6 位作者 Yulong Zhang Guili Yang Ruixiang Wang Yuzhe Liu Peize Zhang Yaxin Zhang Xiao Wang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期430-442,共13页
As the basic protective element, steel plate had attracted world-wide attention because of frequent threats of explosive loads. This paper reports the relationships between microscopic defects of Q345 steel plate unde... As the basic protective element, steel plate had attracted world-wide attention because of frequent threats of explosive loads. This paper reports the relationships between microscopic defects of Q345 steel plate under the explosive load and its macroscopic dynamics simulation. Firstly, the defect characteristics of the steel plate were investigated by stereoscopic microscope(SM) and scanning electron microscope(SEM). At the macroscopic level, the defect was the formation of cave which was concentrated in the range of 0-3.0 cm from the explosion center, while at the microscopic level, the cavity and void formation were the typical damage characteristics. It also explains that the difference in defect morphology at different positions was the combining results of high temperature and high pressure. Secondly, the variation rules of mechanical properties of steel plate under explosive load were studied. The Arbitrary Lagrange-Euler(ALE) algorithm and multi-material fluid-structure coupling method were used to simulate the explosion process of steel plate. The accuracy of the method was verified by comparing the deformation of the simulation results with the experimental results, the pressure and stress at different positions on the surface of the steel plate were obtained. The simulation results indicated that the critical pressure causing the plate defects may be approximately 2.01 GPa. On this basis, it was found that the variation rules of surface pressure and microscopic defect area of the Q345 steel plate were strikingly similar, and the corresponding mathematical relationship between them was established. Compared with Monomolecular growth fitting models(MGFM) and Logistic fitting models(LFM), the relationship can be better expressed by cubic polynomial fitting model(CPFM). This paper illustrated that the explosive defect characteristics of metal plate at the microscopic level can be explored by analyzing its macroscopic dynamic mechanical response. 展开更多
关键词 Explosive load Q345 steel Micro defect Finite element simulation Dynamic response Data fitting
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Molecular Dynamics Simulation of Shock Response of CL-20 Co-crystals Containing Void Defects
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作者 Changlin Li Wei Yang +5 位作者 Qiang Gan Yajun Wang Lin Liang Wenbo Zhang Shuangfei Zhu Changgen Feng 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期364-374,共11页
To investigate the effect of void defects on the shock response of hexanitrohexaazaisowurtzitane(CL-20)co-crystals,shock responses of CL-20 co-crystals with energetic materials ligands trinitrotoluene(TNT),1,3-dinitro... To investigate the effect of void defects on the shock response of hexanitrohexaazaisowurtzitane(CL-20)co-crystals,shock responses of CL-20 co-crystals with energetic materials ligands trinitrotoluene(TNT),1,3-dinitrobenzene(DNB),solvents ligands dimethyl carbonate(DMC) and gamma-butyrolactone(GBL)with void were simulated,using molecular dynamics method and reactive force field.It is found that the CL-20 co-crystals with void defects will form hot spots when impacted,significantly affecting the decomposition of molecules around the void.The degree of molecular fragmentation is relatively low under the reflection velocity of 2 km/s,and the main reactions are the formation of dimer and the shedding of nitro groups.The existence of voids reduces the safety of CL-20 co-crystals,which induced the sensitivity of energetic co-crystals CL-20/TNT and CL-20/DNB to increase more significantly.Detonation has occurred under the reflection velocity of 4 km/s,energetic co-crystals are easier to polymerize than solvent co-crystals,and are not obviously affected by voids.The results show that the energy of the wave decreases after sweeping over the void,which reduces the chemical reaction frequency downstream of the void and affects the detonation performance,especially the solvent co-crystals. 展开更多
关键词 CL-20 co-crystals Molecular dynamics simulation Reactive forcefield Impact response Hot spot Void defect
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An Analysis of Specific Categories of Birth Defects and Developmental Disabilities for Children of Participants of the Air Force Health Study
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作者 George J. Knafl 《Open Journal of Epidemiology》 2024年第2期312-330,共19页
Background: The Air Force Health Study collected reproductive outcomes for live-born children of male Air Force veterans of the Vietnam War. Methods: Dioxin values for participants were obtained from blood samples. An... Background: The Air Force Health Study collected reproductive outcomes for live-born children of male Air Force veterans of the Vietnam War. Methods: Dioxin values for participants were obtained from blood samples. Analyses were conducted of occurrence of 16 specific categories of birth defects and developmental disabilities. Children were categorized as conceived before and after the start of participants’ Vietnam War service. Children conceived before the start of Vietnam War service were treated as being conceived when their fathers had unquantifiable dioxin values. Children conceived after the start of Vietnam War service for participants with missing dioxin values were excluded from primary analyses, but were used to assess the impact of their exclusion on conclusions. Correlation between values for specific categories for multiple children fathered by the same participant was accounted for. The dose-response relationship was treated as a step function increasing for dioxin values larger than adaptively identified individual thresholds changing with the specific category. Results: For 15 of 16 specific categories, the probability of occurrence increased substantially for a sufficiently high dioxin level above identified thresholds. Exclusion of children due to missing dioxin likely did not affect these results. Conclusions: Results supported the conclusion of substantial adverse effects on a wide variety of specific categories of birth defects and developmental disabilities due to sufficiently high exposures to dioxin, a toxic contaminant of Agent Orange used for herbicide spraying in the Vietnam War. Results may hold more generally, but might also have been affected by a variety of limitations. 展开更多
关键词 Agent Orange Air Force Health Study Birth defects Developmental Disabilities DIOXIN Dose-Response Relationship Vietnam War
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Association of Congenital Heart Defects (CHD) with Factors Related to Maternal Health and Pregnancy in Newborns in Puerto Rico
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作者 Yamixa Delgado Caliani Gaytan +3 位作者 Naydi Perez Eric Miranda Bryan Colón Morales Mónica Santos 《Congenital Heart Disease》 SCIE 2024年第1期19-31,共13页
Background:Given the pervasive issues of obesity and diabetes both in Puerto Rico and the broader United States,there is a compelling need to investigate the intricate interplay among body mass index(BMI),pregesta-tio... Background:Given the pervasive issues of obesity and diabetes both in Puerto Rico and the broader United States,there is a compelling need to investigate the intricate interplay among body mass index(BMI),pregesta-tional,and gestational maternal diabetes,and their potential impact on the occurrence of congenital heart defects(CHD)during neonatal development.Methods:Using the comprehensive System of Vigilance and Surveillance of Congenital Defects in Puerto Rico,we conducted a focused analysis on neonates diagnosed with CHD between 2016 and 2020.Our assessment encompassed a range of variables,including maternal age,gestational age,BMI,pregestational diabetes,gestational diabetes,hypertension,history of abortion,and presence of preeclampsia.Results:A cohort of 673 patients was included in our study.The average maternal age was 26 years,within a range of 22 to 32 years.The mean gestational age measured 39 weeks,with a median span of 38 to 39 weeks.Of the 673 patients,274(41%)mothers gave birth to neonates diagnosed with CHD.Within this group,22 cases were linked to pre-gestational diabetes,while 202 were not;20 instances were associated with gestational diabetes,compared to 200 without;and 148 cases exhibited an overweight or obese BMI,whereas 126 displayed a normal BMI.Conclusion:We identified a statistically significant correlation between pre-gestational diabetes mellitus and the occurrence of CHD.However,our analysis did not show a statistically significant association between maternal BMI and the likelihood of CHD.These results may aid in developing effective strategies to prevent and manage CHD in neonates. 展开更多
关键词 Congenital heart defects(CHD) obesisty maternal health DIABETES body mass index(BMI)
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Interface optimization and defects suppression via Na F introduction enable efficient flexible Sb_(2)Se_(3) thin-film solar cells
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作者 Mingdong Chen Muhammad Ishaq +7 位作者 Donglou Ren Hongli Ma Zhenghua Su Ping Fan David Le Coq Xianghua Zhang Guangxing Liang Shuo Chen 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第3期165-175,I0006,共12页
Sb_(2)Se_(3) with unique one-dimensional(1D) crystal structure exhibits exceptional deformation tolerance,demonstrating great application potential in flexible devices.However,the power conversion efficiency(PCE) of f... Sb_(2)Se_(3) with unique one-dimensional(1D) crystal structure exhibits exceptional deformation tolerance,demonstrating great application potential in flexible devices.However,the power conversion efficiency(PCE) of flexible Sb_(2)Se_(3) photovoltaic devices is temporarily limited by the complicated intrinsic defects and the undesirable contact interfaces.Herein,a high-quality Sb_(2)Se_(3) absorber layer with large crystal grains and benign [hkl] growth orientation can be first prepared on a Mo foil substrate.Then NaF intermediate layer is introduced between Mo and Sb_(2)Se_(3),which can further optimize the growth of Sb_(2)Se_(3)thin film.Moreover,positive Na ion diffusion enables it to dramatically lower barrier height at the back contact interface and passivate harmful defects at both bulk and heterojunction.As a result,the champion substrate structured Mo-foil/Mo/NaF/Sb_(2)Se_(3)/CdS/ITO/Ag flexible thin-film solar cell delivers an obviously higher efficiency of 8.03% and a record open-circuit voltage(V_(OC)) of 0.492 V.This flexible Sb_(2)Se_(3) device also exhibits excellent stability and flexibility to stand large bending radius and multiple bending times,as well as superior weak light photo-response with derived efficiency of 12.60%.This work presents an effective strategy to enhance the flexible Sb_(2)Se_(3) device performance and expand its potential photovoltaic applications. 展开更多
关键词 Sb_(2)Se_(3) Flexible solar cells naF intermediate layer Interface optimization defects suppression
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Impact Analysis of Microscopic Defect Types on the Macroscopic Crack Propagation in Sintered Silver Nanoparticles
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作者 Zhongqing Zhang Bo Wan +4 位作者 Guicui Fu Yutai Su Zhaoxi Wu Xiangfen Wang Xu Long 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第4期441-458,共18页
Sintered silver nanoparticles(AgNPs)arewidely used in high-power electronics due to their exceptional properties.However,the material reliability is significantly affected by various microscopic defects.In this work,t... Sintered silver nanoparticles(AgNPs)arewidely used in high-power electronics due to their exceptional properties.However,the material reliability is significantly affected by various microscopic defects.In this work,the three primary micro-defect types at potential stress concentrations in sintered AgNPs are identified,categorized,and quantified.Molecular dynamics(MD)simulations are employed to observe the failure evolution of different microscopic defects.The dominant mechanisms responsible for this evolution are dislocation nucleation and dislocation motion.At the same time,this paper clarifies the quantitative relationship between the tensile strain amount and the failure mechanism transitions of the three defect types by defining key strain points.The impact of defect types on the failure process is also discussed.Furthermore,traction-separation curves extracted from microscopic defect evolutions serve as a bridge to connect the macro-scale model.The validity of the crack propagation model is confirmed through tensile tests.Finally,we thoroughly analyze how micro-defect types influence macro-crack propagation and attempt to find supporting evidence from the MD model.Our findings provide a multi-perspective reference for the reliability analysis of sintered AgNPs. 展开更多
关键词 Sintered silver nanoparticles defect types microscopic defect evolution macroscopic crack propagation molecular dynamics simulation cohesive zone model
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Built defects of homogeneous junction to enhance the lithium storage capacity of niobium pentoxide materials
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作者 Huibin Ding Yang Luo +5 位作者 Zihan Song Cong Chen Kai Feng Xiaofei Yang Hongzhang Zhang Xianfeng Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第5期730-737,共8页
Niobium pentoxide(Nb_(2)O_(5))is deemed one of the promising anode materials for lithium-ion batteries(LIBs)for its outstanding intrinsic fast Li-(de)intercalation kinetics.The specific capacity,however,is still limit... Niobium pentoxide(Nb_(2)O_(5))is deemed one of the promising anode materials for lithium-ion batteries(LIBs)for its outstanding intrinsic fast Li-(de)intercalation kinetics.The specific capacity,however,is still limited,because the(de)intercalation of excessive Li-ions brings the undesired stress to damage Nb_(2)O_(5) crystals.To increase the capacity of Nb_(2)O_(5) and alleviate the lattice distortion caused by stress,numerous homogeneous H-and M-phases junction interfaces were proposed to produce coercive stress within theNb_(2)O_(5)crystals.Such interfaces bring about rich oxygen vacancies with structural shrinkage tendency,which pre-generate coercive stress to resist the expansion stress caused by excessive Li-ions intercalation.Therefore,the synthesized Nb_(2)O_(5) achieves the highest lithium storage capacity of 315 mA h g−1 to date,and exhibits high-rate performance(118 mA h g^(-1) at 20 C)as well as excellent cycling stability(138 mA h g^(-1) at 10 C after 600 cycles). 展开更多
关键词 Niobiumpent oxide Homojunction polycrystalline defects Oxygen vacancy
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Effect of Vacancy Defects on the Properties of CoS_(2) and FeS_(2)
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作者 冯中营 ZHANG Jianmin +3 位作者 WANG Xiaowei YANG Wenjin JING Yinlan YANG Yan 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第3期627-638,共12页
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
关键词 cobalt disulfide iron disulfide vacancy defect fist principles
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SAM Era:Can It Segment Any Industrial Surface Defects?
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作者 Kechen Song Wenqi Cui +2 位作者 Han Yu Xingjie Li Yunhui Yan 《Computers, Materials & Continua》 SCIE EI 2024年第3期3953-3969,共17页
Segment Anything Model(SAM)is a cutting-edge model that has shown impressive performance in general object segmentation.The birth of the segment anything is a groundbreaking step towards creating a universal intellige... Segment Anything Model(SAM)is a cutting-edge model that has shown impressive performance in general object segmentation.The birth of the segment anything is a groundbreaking step towards creating a universal intelligent model.Due to its superior performance in general object segmentation,it quickly gained attention and interest.This makes SAM particularly attractive in industrial surface defect segmentation,especially for complex industrial scenes with limited training data.However,its segmentation ability for specific industrial scenes remains unknown.Therefore,in this work,we select three representative and complex industrial surface defect detection scenarios,namely strip steel surface defects,tile surface defects,and rail surface defects,to evaluate the segmentation performance of SAM.Our results show that although SAM has great potential in general object segmentation,it cannot achieve satisfactory performance in complex industrial scenes.Our test results are available at:https://github.com/VDT-2048/SAM-IS. 展开更多
关键词 Segment anything SAM surface defect detection salient object detection
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Method for Detecting Industrial Defects in Intelligent Manufacturing Using Deep Learning
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作者 Bowen Yu Chunli Xie 《Computers, Materials & Continua》 SCIE EI 2024年第1期1329-1343,共15页
With the advent of Industry 4.0,marked by a surge in intelligent manufacturing,advanced sensors embedded in smart factories now enable extensive data collection on equipment operation.The analysis of such data is pivo... With the advent of Industry 4.0,marked by a surge in intelligent manufacturing,advanced sensors embedded in smart factories now enable extensive data collection on equipment operation.The analysis of such data is pivotal for ensuring production safety,a critical factor in monitoring the health status of manufacturing apparatus.Conventional defect detection techniques,typically limited to specific scenarios,often require manual feature extraction,leading to inefficiencies and limited versatility in the overall process.Our research presents an intelligent defect detection methodology that leverages deep learning techniques to automate feature extraction and defect localization processes.Our proposed approach encompasses a suite of components:the high-level feature learning block(HLFLB),the multi-scale feature learning block(MSFLB),and a dynamic adaptive fusion block(DAFB),working in tandem to extract meticulously and synergistically aggregate defect-related characteristics across various scales and hierarchical levels.We have conducted validation of the proposed method using datasets derived from gearbox and bearing assessments.The empirical outcomes underscore the superior defect detection capability of our approach.It demonstrates consistently high performance across diverse datasets and possesses the accuracy required to categorize defects,taking into account their specific locations and the extent of damage,proving the method’s effectiveness and reliability in identifying defects in industrial components. 展开更多
关键词 Industrial defect detection deep learning intelligent manufacturing
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Surgical Repair of Ventricular Septal Defect in Neonates: Indications and Outcomes
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作者 Jae Hong Lee Sungkyu Cho +6 位作者 Jae Gun Kwak Hye Won Kwon Woong-Han Kim Mi Kyoung Song Sang-Yun Lee Gi Beom Kim Eun Jung Bae 《Congenital Heart Disease》 SCIE 2024年第1期69-83,共15页
Background:The optimal surgical timing and clinical outcomes of ventricular septal defect(VSD)closure in neo-nates remain unclear.We aimed to evaluate the clinical outcomes of VSD closure in neonates(age≤30 days).Met... Background:The optimal surgical timing and clinical outcomes of ventricular septal defect(VSD)closure in neo-nates remain unclear.We aimed to evaluate the clinical outcomes of VSD closure in neonates(age≤30 days).Methods:We retrospectively reviewed 50 consecutive neonates who underwent VSD closure for isolated VSDs between August 2003 and June 2021.Indications for the procedure included congestive heart failure/failure to thrive and pulmonary hypertension.Major adverse events(MAEs)were defined as the composite of all-cause mortality,reoperation,persistent atrioventricular block,and significant(≥grade 2)valvular dysfunction.Results:The median age and body weight at operation were 26.0 days(interquartile range[IQR],18.8–28.3)and 3.7 kg(IQR,3.3–4.2),respectively.The median follow-up duration was 110.4 months(IQR,56.8–165.0).Seven patients required preoperative respiratory support,andfive had significant(≥grade 2)preoperative valvular dysfunction.One early mortality occurred due to irreversible cardiogenic shock;no late mortality was observed.One reopera-tion was due to hemodynamically significant residual VSD at 103.8 months postoperatively.The overall survival,freedom from reoperation,and freedom from MAE at 15-years were 98.0%,96.3%,and 94.4%,respectively.Pre-operative mechanical ventilation was associated with a longer duration of postoperative mechanical ventilation(p<0.001)and a longer length of intensive care unit stay(p<0.001).Conclusions:VSD closure with favorable outcomes without morbidities is feasible even in neonates.However,neonates requiring preoperative respiratory support may require careful postoperative management considering the long-term postoperative risks.Overall,surgical VSD closure might be indicated earlier in neonates with respiratory compromise. 展开更多
关键词 Ventricular septal defect NEOnaTE early surgery neonatal surgery
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Customized scaffolds for large bone defects using 3D‑printed modular blocks from 2D‑medical images
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作者 Anil AAcar Evangelos Daskalakis +4 位作者 Paulo Bartolo Andrew Weightman Glen Cooper Gordon Blunn Bahattin Koc 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第1期74-87,共14页
Additive manufacturing(AM)has revolutionized the design and manufacturing of patient-specific,three-dimensional(3D),complex porous structures known as scaffolds for tissue engineering applications.The use of advanced ... Additive manufacturing(AM)has revolutionized the design and manufacturing of patient-specific,three-dimensional(3D),complex porous structures known as scaffolds for tissue engineering applications.The use of advanced image acquisition techniques,image processing,and computer-aided design methods has enabled the precise design and additive manufacturing of anatomically correct and patient-specific implants and scaffolds.However,these sophisticated techniques can be timeconsuming,labor-intensive,and expensive.Moreover,the necessary imaging and manufacturing equipment may not be readily available when urgent treatment is needed for trauma patients.In this study,a novel design and AM methods are proposed for the development of modular and customizable scaffold blocks that can be adapted to fit the bone defect area of a patient.These modular scaffold blocks can be combined to quickly form any patient-specific scaffold directly from two-dimensional(2D)medical images when the surgeon lacks access to a 3D printer or cannot wait for lengthy 3D imaging,modeling,and 3D printing during surgery.The proposed method begins with developing a bone surface-modeling algorithm that reconstructs a model of the patient’s bone from 2D medical image measurements without the need for expensive 3D medical imaging or segmentation.This algorithm can generate both patient-specific and average bone models.Additionally,a biomimetic continuous path planning method is developed for the additive manufacturing of scaffolds,allowing porous scaffold blocks with the desired biomechanical properties to be manufactured directly from 2D data or images.The algorithms are implemented,and the designed scaffold blocks are 3D printed using an extrusion-based AM process.Guidelines and instructions are also provided to assist surgeons in assembling scaffold blocks for the self-repair of patient-specific large bone defects. 展开更多
关键词 Additive manufacturing Modular scaffolds Large bone defect Customized scaffold design Patient-specific scaffolds
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Cross-Project Software Defect Prediction Based on SMOTE and Deep Canonical Correlation Analysis
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作者 Xin Fan Shuqing Zhang +2 位作者 Kaisheng Wu Wei Zheng Yu Ge 《Computers, Materials & Continua》 SCIE EI 2024年第2期1687-1711,共25页
Cross-Project Defect Prediction(CPDP)is a method that utilizes historical data from other source projects to train predictive models for defect prediction in the target project.However,existing CPDP methods only consi... Cross-Project Defect Prediction(CPDP)is a method that utilizes historical data from other source projects to train predictive models for defect prediction in the target project.However,existing CPDP methods only consider linear correlations between features(indicators)of the source and target projects.These models are not capable of evaluating non-linear correlations between features when they exist,for example,when there are differences in data distributions between the source and target projects.As a result,the performance of such CPDP models is compromised.In this paper,this paper proposes a novel CPDP method based on Synthetic Minority Oversampling Technique(SMOTE)and Deep Canonical Correlation Analysis(DCCA),referred to as S-DCCA.Canonical Correlation Analysis(CCA)is employed to address the issue of non-linear correlations between features of the source and target projects.S-DCCA extends CCA by incorporating the MlpNet model for feature extraction from the dataset.The redundant features are then eliminated by maximizing the correlated feature subset using the CCA loss function.Finally,cross-project defect prediction is achieved through the application of the SMOTE data sampling technique.Area Under Curve(AUC)and F1 scores(F1)are used as evaluation metrics.This paper conducted experiments on 27 projects from four public datasets to validate the proposed method.The results demonstrate that,on average,our method outperforms all baseline approaches by at least 1.2%in AUC and 5.5%in F1 score.This indicates that the proposed method exhibits favorable performance characteristics. 展开更多
关键词 Cross-project defect prediction deep canonical correlation analysis feature similarity
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Clinical management of dural defects:A review 被引量:1
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作者 Rong-Peng Dong Qi Zhang +2 位作者 Li-Li Yang Xue-Liang Cheng Jian-Wu Zhao 《World Journal of Clinical Cases》 SCIE 2023年第13期2903-2915,共13页
Dural defects are common in spinal and cranial neurosurgery.A series of complications,such as cerebrospinal fluid leakage,occur after rupture of the dura.Therefore,treatment strategies are necessary to reduce or avoid... Dural defects are common in spinal and cranial neurosurgery.A series of complications,such as cerebrospinal fluid leakage,occur after rupture of the dura.Therefore,treatment strategies are necessary to reduce or avoid complications.This review comprehensively summarizes the common causes,risk factors,clinical complications,and repair methods of dural defects.The latest research progress on dural repair methods and materials is summarized,including direct sutures,grafts,biomaterials,non-biomaterial materials,and composites formed by different materials.The characteristics and efficacy of these dural substitutes are reviewed,and these materials and methods are systematically evaluated.Finally,the best methods for dural repair and the challenges and future prospects of new dural repair materials are discussed. 展开更多
关键词 Dural defect Cerebrospinal fluid leak Incidental durotomy Causes of dural defect Dural repair
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Synergically enhanced piezocatalysis performance of eco-friendly(K_(0.52)Na_(0.48))NbO_(3) through ferroelectric polarization and defects 被引量:1
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作者 Min Zhou Laijun Liang +8 位作者 Dingze Lu Xiaomei Lu Zheng Wang Fengzhen Huang Pengfei Cheng Dongdong Liu Mengqi Tian Qiuping Wang Yunjie Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第10期2044-2054,共11页
Piezocatalysis has attracted unprecedented research interest as a newly emerging catalysis technology.However,the inherent insulating property of ferroelectric materials ultimately leads to the poor vibration-electric... Piezocatalysis has attracted unprecedented research interest as a newly emerging catalysis technology.However,the inherent insulating property of ferroelectric materials ultimately leads to the poor vibration-electricity conversion ability.Herein,this work reports the(K_(0.52)Na_(0.48))NbO_(3) ferroelectric ceramics(KNNFCx),for which the FeCo modification strategy is proposed.The substitution of the moderate amount of FeCo(x=0.015)at Nb site not only optimizes ferroelectricity but also produces beneficial defects,notably increasing Rhodamine B water purification efficiency to 95%.The pinning effect of monovalent oxygen vacancies on ferroelectric domains is responsible for the excellent ferroelectric polarization of KNNFC0.015 through the generation of an internal field to promote charge carriers separation and reduce nonradiative recombination.Importantly,the accompanying electron carriers can easily move to the material surface and participate in redox reactions because they have low activation energy.Therefore,ferroelectric polarization and defects play synergetic roles in enhancing piezocatalytic performance. 展开更多
关键词 piezocatalytic water purification ferroelectric polarization beneficial defects
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Similarity evaluation model for the internal defect detection of strip steel
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作者 ZHANG Yalin WANG Yaojie WANG Xuemin 《Baosteel Technical Research》 CAS 2024年第1期8-13,共6页
An internal defect meter is an instrument to detect the internal inclusion defects of cold-rolled strip steel.The detection accuracy of the equipment can be evaluated based on the similarity of the multiple detection ... An internal defect meter is an instrument to detect the internal inclusion defects of cold-rolled strip steel.The detection accuracy of the equipment can be evaluated based on the similarity of the multiple detection data obtained for the same steel coil.Based on the cosine similarity model and eigenvalue matrix model,a comprehensive evaluation method to calculate the weighted average of similarity is proposed.Results show that the new method is consistent with and can even replace artificial evaluation to realize the automatic evaluation of strip defect detection results. 展开更多
关键词 internal defect INCLUSION similarity evaluation model REPEATABILITY detection equipment strip steel
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Industry-Oriented Detection Method of PCBA Defects Using Semantic Segmentation Models
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作者 Yang Li Xiao Wang +10 位作者 Zhifan He Ze Wang Ke Cheng Sanchuan Ding Yijing Fan Xiaotao Li Yawen Niu Shanpeng Xiao Zhenqi Hao Bin Gao Huaqiang Wu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第6期1438-1446,共9页
Automated optical inspection(AOI)is a significant process in printed circuit board assembly(PCBA)production lines which aims to detect tiny defects in PCBAs.Existing AOI equipment has several deficiencies including lo... Automated optical inspection(AOI)is a significant process in printed circuit board assembly(PCBA)production lines which aims to detect tiny defects in PCBAs.Existing AOI equipment has several deficiencies including low throughput,large computation cost,high latency,and poor flexibility,which limits the efficiency of online PCBA inspection.In this paper,a novel PCBA defect detection method based on a lightweight deep convolution neural network is proposed.In this method,the semantic segmentation model is combined with a rule-based defect recognition algorithm to build up a defect detection frame-work.To improve the performance of the model,extensive real PCBA images are collected from production lines as datasets.Some optimization methods have been applied in the model according to production demand and enable integration in lightweight computing devices.Experiment results show that the production line using our method realizes a throughput more than three times higher than traditional methods.Our method can be integrated into a lightweight inference system and pro-mote the flexibility of AOI.The proposed method builds up a general paradigm and excellent example for model design and optimization oriented towards industrial requirements. 展开更多
关键词 Automated optical inspection(AOI) deep learning defect detection printed circuit board assembly(PCBA) semantic segmentation.
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High quality repair of osteochondral defects in rats using the extracellular matrix of antler stem cells
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作者 Yu-Su Wang Wen-Hui Chu +4 位作者 Jing-Jie Zhai Wen-Ying Wang Zhong-Mei He Quan-Min Zhao Chun-Yi Li 《World Journal of Stem Cells》 SCIE 2024年第2期176-190,共15页
BACKGROUND Cartilage defects are some of the most common causes of arthritis.Cartilage lesions caused by inflammation,trauma or degenerative disease normally result in osteochondral defects.Previous studies have shown... BACKGROUND Cartilage defects are some of the most common causes of arthritis.Cartilage lesions caused by inflammation,trauma or degenerative disease normally result in osteochondral defects.Previous studies have shown that decellularized extracellular matrix(ECM)derived from autologous,allogenic,or xenogeneic mesenchymal stromal cells(MSCs)can effectively restore osteochondral integrity.AIM To determine whether the decellularized ECM of antler reserve mesenchymal cells(RMCs),a xenogeneic material from antler stem cells,is superior to the currently available treatments for osteochondral defects.METHODS We isolated the RMCs from a 60-d-old sika deer antler and cultured them in vitro to 70%confluence;50 mg/mL L-ascorbic acid was then added to the medium to stimulate ECM deposition.Decellularized sheets of adipocyte-derived MSCs(aMSCs)and antlerogenic periosteal cells(another type of antler stem cells)were used as the controls.Three weeks after ascorbic acid stimulation,the ECM sheets were harvested and applied to the osteochondral defects in rat knee joints.RESULTS The defects were successfully repaired by applying the ECM-sheets.The highest quality of repair was achieved in the RMC-ECM group both in vitro(including cell attachment and proliferation),and in vivo(including the simultaneous regeneration of well-vascularized subchondral bone and avascular articular hyaline cartilage integrated with surrounding native tissues).Notably,the antler-stem-cell-derived ECM(xenogeneic)performed better than the aMSC-ECM(allogenic),while the ECM of the active antler stem cells was superior to that of the quiescent antler stem cells.CONCLUSION Decellularized xenogeneic ECM derived from the antler stem cell,particularly the active form(RMC-ECM),can achieve high quality repair/reconstruction of osteochondral defects,suggesting that selection of decellularized ECM for such repair should be focused more on bioactivity rather than kinship. 展开更多
关键词 Osteochondral defect repair Mesenchymal stem cells Extracellular matrix DECELLULARIZATION Antler stem cells Reserve mesenchymal cells Xenogeneic
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