Prisoner’s Dilemma is a master trope for relaying the permanent impasse or dilemma of cooperation versus defection.In Prisoner’s Dilemma Richard Powers narrates a multiform of dilemma mainly narrating Eddie Hobson’...Prisoner’s Dilemma is a master trope for relaying the permanent impasse or dilemma of cooperation versus defection.In Prisoner’s Dilemma Richard Powers narrates a multiform of dilemma mainly narrating Eddie Hobson’s traumatic history,along with Eddie’s attempt to carry out a strategy—Eddie’s ideal Hobstown which is supposed to cope with the confused dilemma.Pow⁃ers’strategic moral insights are revealed by assuming that each player feels sympathy for the other and a moral cooperative instead of antagonistic solution to the Prisoner’s Dilemma will be found.展开更多
Without cooperative behaviors, our society or organization falls into social dilemma situations where every member selects uncooperative （defective） behaviors, and the situation gets worse and worse. Such a situatio...Without cooperative behaviors, our society or organization falls into social dilemma situations where every member selects uncooperative （defective） behaviors, and the situation gets worse and worse. Such a situation in a society or an organization leads to violation of social or organizational rules, and at the worst case it suffers from serious accidents or scandals. Therefore, it is important for us to make efforts and take measures to elicit cooperative behaviors. It was demonstrated theoretically that altruism strategy and adaptive prediction and ascertainment strategy are in some cases better than rational strategy under the situation of social dilemma. We built up a mathematical model in order to examine how the probability of correctly predicting and ascertaining the behavior （cooperation or defection） of opponents and the mixture of （a） altruism （all cooperation） strategy, （b） individualism （all defection） strategy, and （c） adaptive prediction and ascertainment strategy affected the expected profit. Simulation results showed that the tit-for-tat strategy was better than the rational （individualism） strategy when the probability of correctly predicting and ascertaining defection of the opponent was considerably higher. As an application of the basic study above, it was explored, using a simulation method, how such a system as opening reputation or peer review in public could work satisfactorily to prevent defective behaviors in auction dealing. The result showed that the information on the handle name and the reputation effectively worked to prevent defective behaviors.展开更多
In this study,we examine the problem of predicting customer defection in a noncontractual setting.Motivated by recent work on machine learning using multiple time slices,we develop a novel training and testing framewo...In this study,we examine the problem of predicting customer defection in a noncontractual setting.Motivated by recent work on machine learning using multiple time slices,we develop a novel training and testing framework,the sliding multi-time slicing(SMTS)method.We apply this method to data from the largest marketplace in Greece,namely,Skroutz,considering the standard features that account for the important characteristics of customer activity and custom performance metrics aimed at capturing business-related goals established by the company.The dataset comprises customers over a relatively short period,since April 2018,the number of which has also exhibited a significant increase in recent months.Despite these difficulties and the inherent seasonality of customer defection,our results demonstrate that,with SMTS,developing models that outperform previous approaches and optimize decision-making is possible.We validate the approach to a benchmark dataset from the commerce sector and discuss the practical considerations and requirements of the proposed method.展开更多
In our society, it is a major issue to enhance cooperative behaviors. Without this, our society fall into social dilemma situations, and gets worse and worse. Such a situation in an organization leads to violation of ...In our society, it is a major issue to enhance cooperative behaviors. Without this, our society fall into social dilemma situations, and gets worse and worse. Such a situation in an organization leads to violation of social or organizational rules, and at the worst case it suffers from serious accidents or scandals. Therefore, it is important for organizational managers to make efforts and take measures to enhance cooperative behaviors. Although there seem to be many ways to constantly elicit cooperative behaviors, the punishment is one of the most effective measures for enhancing cooperation. This study focused on the effects of penalty and probability of the revelation of defection on the cooperation, and getting insight into how punishment strategy should be used to get rid of social dilemmas and enhance cooperation. This study conducted a simulation experiment to find the proper penal regulations condition that can suppress violations （defective behavior） in a 2-person prisoner＇s dilemma situation. The effects of probability of the revelation of defection and penalty to revelation on the cooperative behavior were identified with the interactive effect of both experimental factors. The defection （uncooperative behavior） decreased when the penalty to the defection was heavy and the probability of the revelation of defection was low than that when the penalty to the defection was light and the probability of the revelation of the defection was high.展开更多
T he residual stray magnetic fields present in ferromagnetic casting slabs were investigated in this work,which result from the magnetic fields generated during the steel casting process.Existing optical detection met...T he residual stray magnetic fields present in ferromagnetic casting slabs were investigated in this work,which result from the magnetic fields generated during the steel casting process.Existing optical detection methods face challenges owing to surface oxide scales,and conventional high-precision magnetic sensors are ineffective at high temperatures.To overcome these limitations,a small coil sensor was employed to measure the residual magnetism strength in oscillation traces,using metal magnetic memory and electromagnetic induction methods,which can carry out detection without an external excitation source.Using this technology,the proposed scheme successfully detects defects at high tempe-ratures(up to 670℃)without a cooling device.The key findings include the ability to detect both surface and near-surface defects,such as cracks and oscillation marks,with an enhanced signal-to-noise ratio(SNR)of 7.2 dB after signal processing.The method’s practicality was validated in a steel mill environment,where testing on casting slabs effectively detected defects,providing a foundation for improving industrial quality control.The proposed detection scheme offers a significant advancement in nondestructive testing(NDT)for high-temperature applications,contributing to more efficient and accurate monitoring of ferromagnetic material integrity.展开更多
Biomass-derived carbon materials are favored for their abundance and sustainability,and ease of preparation and modification.By surface activation and modification they can have a good electrical conductivity,excellen...Biomass-derived carbon materials are favored for their abundance and sustainability,and ease of preparation and modification.By surface activation and modification they can have a good electrical conductivity,excellent catalytic activity,a remarkable adsorption capacity,and different interfacial physicochemical functionalities.Surface-modified biochars have found wide applications in energy storage,environmental remediation,and catalysis.However,achieving precise and controllable modification of their active sites remains a challenge.Recent advances and future prospects for controlling their surface morphology,defect engineering,and surface coating strategies,with particular attention to their means of fabrication,are reviewed.展开更多
Although the certified power conversion efficiency(PCE)of single-junction perovskite solar cells(PSCs)has achieved a high level of 27%,approaching the single-crystalline silicon solar cells,the device stability remain...Although the certified power conversion efficiency(PCE)of single-junction perovskite solar cells(PSCs)has achieved a high level of 27%,approaching the single-crystalline silicon solar cells,the device stability remains an urgent issue to be resolved for the commercialization.Defect passivation emerged as a viable approach to enhance the operational stability of the solar devices.Herein,phenylthiourea(PhTu)derivatives are selected as effective passivation agents to enhance the optoelectronic properties of printed methylammonium lead iodide(MAPbI_(3))films.It is demonstrated that incorporating a small amount of 1-(4-carboxyphenyl)-2-thiourea(PhTu-COOH)significantly reduces the trap-state density and leads to longer carrier lifetime of the perovskite films.As a result,the inverted solar device made of Ph Tu-COOH-modified MAPbI_(3) perovskite film shows remarkably improved efficiency(from 17.29%to 20.22%)and obviously increased open-circuit voltage(V_(OC))(from 1.043 to 1.143 V),as compared with the pristine device.Moreover,the Ph Tu-COOH-modified PSCs exhibit enhanced operational stability due to the significantly reduced trap-state density.Finally,the optimized solar module fabricated with an active area of 11.28 cm^(2) delivers a high PCE of 17.07%with negligible V_(OC)loss,demonstrating the feasibility of the blade-coating method for large-area perovskite film deposition.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
Perovskite solar cells(PSCs)have emerged as promising photovoltaic technologies owing to their remarkable power conversion efficiency(PCE).However,heat accumulation under continuous illumination remains a critical bot...Perovskite solar cells(PSCs)have emerged as promising photovoltaic technologies owing to their remarkable power conversion efficiency(PCE).However,heat accumulation under continuous illumination remains a critical bottleneck,severely affecting device stability and long-term operational performance.Herein,we present a multifunctional strategy by incorporating highly thermally conductive Ti_(3)C_(2)T_(X) MXene nanosheets into the perovskite layer to simultaneously enhance thermal management and optoelectronic properties.The Ti_(3)C_(2)T_(X) nanosheets,embedded at perovskite grain boundaries,construct efficient thermal conduction pathways,significantly improving the thermal conductivity and diffusivity of the film.This leads to a notable reduction in the device’s steady-state operating temperature from 42.96 to 39.97 under 100 mW cm^(−2) illumination,thereby alleviating heat-induced performance degradation.Beyond thermal regulation,Ti_(3)C_(2)T_(X),with high conductivity and negatively charged surface terminations,also serves as an effective defect passivation agent,reducing trap-assisted recombination,while simultaneously facilitating charge extraction and transport by optimizing interfacial energy alignment.As a result,the Ti_(3)C_(2)T_(X)-modified PSC achieve a champion PCE of 25.13%and exhibit outstanding thermal stability,retaining 80%of the initial PCE after 500 h of thermal aging at 85 and 30±5%relative humidity.(In contrast,control PSC retain only 58%after 200 h.)Moreover,under continuous maximum power point tracking in N2 atmosphere,Ti_(3)C_(2)T_(X)-modified PSC retained 70%of the initial PCE after 500 h,whereas the control PSC drop sharply to 20%.These findings highlight the synergistic role of Ti_(3)C_(2)T_(X) in thermal management and optoelectronic performance,paving the way for the development of high-efficiency and heat-resistant perovskite photovoltaics.展开更多
Conversion-type electrode materials hold significant promise for potassium-ion batteries(PIBs)due to their high theoretical capacities,yet their practical deployment is hindered by sluggish kinetics and irreversible s...Conversion-type electrode materials hold significant promise for potassium-ion batteries(PIBs)due to their high theoretical capacities,yet their practical deployment is hindered by sluggish kinetics and irreversible structural degradation.To overcome these limitations,we propose a rationally engineered nanoreactor architecture that stabilizes defect-rich MoS_(2)via interlayer incorporation of a carbon monolayer,followed by encapsulation within a nitrogen-doped carbon shell,forming a MoSSe@NC heterostructure.This tailored structure synergistically accelerates both K^(+)diffusion kinetics and electron transfer,enabling unprecedented rate performance(107 mAh g^(-1)at 10 Ag^(-1))and ultralong cyclability(86.5%capacity retention after 1200 cycles at 3 A g^(-1)).Mechanistic insights reveal a distinctive“adsorption-conversion”pathway,where sulfur vacancies on exposed S-Mo-S basal planes act as preferential K^(+)adsorption sites,effectively suppressing parasitic phase transitions during intercalation.In situ X-ray diffraction and transmission electron microscopy corroborate the structural reversibility of the conversion reaction,with the carbon matrix dynamically accommodating strain while preserving electrode integrity.This work not only advances the understanding of defect-driven interfacial chemistry in conversion-type materials but also provides a versatile strategy for designing high-performance anodes in next-generation PIBs through heterostructure engineering.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
Soil desiccation cracking is a prevalent natural phenomenon that poses significant geotechnical and geoenvironmental challenges.Cracks typically initiate at surface defects such as air bubbles,large aggregates,tiny pi...Soil desiccation cracking is a prevalent natural phenomenon that poses significant geotechnical and geoenvironmental challenges.Cracks typically initiate at surface defects such as air bubbles,large aggregates,tiny pits,or uneven surfaces,where localized stress concentrations are readily induced.This study conducted a series of laboratory desiccation tests on slurry samples to investigate the initiation and propagation of desiccation cracks in the presence of varying types and quantities of surface defects.Digital image correlation(DIC)technology was employed to monitor the strain and displacement fields on the soil surface during the desiccation process.The results reveal that strain and displacement data derived from DIC can precisely predict the initiation sites and propagation directions of desiccation cracks.In samples with internal defects,cracks predominantly propagate through the defect,whereas external defects tend to initiate cracks along their edges.In samples with multiple defects,Y-shaped crack patterns generally form initially,followed by T-shaped and straight cracks,driven by the evolving stress field.The dynamic interplay between crack formation and tensile stress redistribution governs the initiation and propagation of desiccation cracks.展开更多
Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphi...Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphite.This study utilizes the porous“defect advantage”of a cathode carbon block matrix to prepare silicon-doped and asphalt-coated detoxified and purified waste graphitization cathode carbon blocks for use as high-performance silicon/carbon composite anode materials.The results show that the uniformly silicondoped silicon/carbon composite material features a unique amorphous carbon-encapsulated“locked silicon”structure,which effectively addresses issues such as cathode volume expansion,excessive growth of the solid electrolyte interphase(SEI)film,and poor electrical contact between active materials.Consequently,electrochemical performance is enhanced.After assembly in a half-cell,the PSCC/10%Si@C(purified waste graphitization cathode carbon/10%Si@C)material exhibits optimal electrochemical stability,with an initial charging specific capacity of 514.5 mAh/g at 0.1 C(1 C=170 mA/g)and a capacity retention rate of 95.1%after 100 cycles.At a charge rate of 2.0 C,a specific capacity of 216.9 mAh/g is achieved.This technology provides a new pathway for the economical and high-value utilization of waste cathode carbon blocks and the development of low-cost,high-performance anode materials.展开更多
N umerous neurological disorders negatively impact the nervous system,either through loss of neurons or by disrupting the normal functioning of neural networks.These impairments manifest as cognitive defects,memory lo...N umerous neurological disorders negatively impact the nervous system,either through loss of neurons or by disrupting the normal functioning of neural networks.These impairments manifest as cognitive defects,memory loss,behavioral abnormalities,and motor dysfunctions.Decades of research have significantly advanced our understanding of the pathophysiology underlying neurodegene rative diseases,including Alzheimer's disease(AD),Parkinson's disease,amyotrophic lateral sclerosis,and others.展开更多
Central venous catheterization(CVC)is a fundamental clinical procedure widely performed across medical specialties.However,the complication rate of subclavian vein catheterization ranges from 6%to 11%.[1]Common compli...Central venous catheterization(CVC)is a fundamental clinical procedure widely performed across medical specialties.However,the complication rate of subclavian vein catheterization ranges from 6%to 11%.[1]Common complications include hemothorax,pneumothorax,air embolism,arterial puncture,and aortic perforation.[2]Herein,we report a rare case of accidental puncture of the aorta during subclavian CVC,which was successfully managed with a ventricular septal defect(VSD)occluder.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
Perovskite quantum dot light-emitting diodes(Pe-QLEDs)have shown immense application potential in display and lighting fields due to their narrow full-width at half maximum(FWHM)and high photoluminescence quantum yiel...Perovskite quantum dot light-emitting diodes(Pe-QLEDs)have shown immense application potential in display and lighting fields due to their narrow full-width at half maximum(FWHM)and high photoluminescence quantum yield(PLQY).Despite significant advancements in their performance,challenges such as defects and ion migration still hinder their long-term stability and operational efficiency.To address these issues,various optimization strategies,including ligand engineering,interface passivation,and self-assembly strategy,are being actively researched.This review focuses on the synthesis methods,challenges and optimization of perovskite quantum dots,which are critical for the commercialization and large-scale production of high-performance and stable Pe-QLEDs.展开更多
文摘Prisoner’s Dilemma is a master trope for relaying the permanent impasse or dilemma of cooperation versus defection.In Prisoner’s Dilemma Richard Powers narrates a multiform of dilemma mainly narrating Eddie Hobson’s traumatic history,along with Eddie’s attempt to carry out a strategy—Eddie’s ideal Hobstown which is supposed to cope with the confused dilemma.Pow⁃ers’strategic moral insights are revealed by assuming that each player feels sympathy for the other and a moral cooperative instead of antagonistic solution to the Prisoner’s Dilemma will be found.
文摘Without cooperative behaviors, our society or organization falls into social dilemma situations where every member selects uncooperative （defective） behaviors, and the situation gets worse and worse. Such a situation in a society or an organization leads to violation of social or organizational rules, and at the worst case it suffers from serious accidents or scandals. Therefore, it is important for us to make efforts and take measures to elicit cooperative behaviors. It was demonstrated theoretically that altruism strategy and adaptive prediction and ascertainment strategy are in some cases better than rational strategy under the situation of social dilemma. We built up a mathematical model in order to examine how the probability of correctly predicting and ascertaining the behavior （cooperation or defection） of opponents and the mixture of （a） altruism （all cooperation） strategy, （b） individualism （all defection） strategy, and （c） adaptive prediction and ascertainment strategy affected the expected profit. Simulation results showed that the tit-for-tat strategy was better than the rational （individualism） strategy when the probability of correctly predicting and ascertaining defection of the opponent was considerably higher. As an application of the basic study above, it was explored, using a simulation method, how such a system as opening reputation or peer review in public could work satisfactorily to prevent defective behaviors in auction dealing. The result showed that the information on the handle name and the reputation effectively worked to prevent defective behaviors.
文摘In this study,we examine the problem of predicting customer defection in a noncontractual setting.Motivated by recent work on machine learning using multiple time slices,we develop a novel training and testing framework,the sliding multi-time slicing(SMTS)method.We apply this method to data from the largest marketplace in Greece,namely,Skroutz,considering the standard features that account for the important characteristics of customer activity and custom performance metrics aimed at capturing business-related goals established by the company.The dataset comprises customers over a relatively short period,since April 2018,the number of which has also exhibited a significant increase in recent months.Despite these difficulties and the inherent seasonality of customer defection,our results demonstrate that,with SMTS,developing models that outperform previous approaches and optimize decision-making is possible.We validate the approach to a benchmark dataset from the commerce sector and discuss the practical considerations and requirements of the proposed method.
文摘In our society, it is a major issue to enhance cooperative behaviors. Without this, our society fall into social dilemma situations, and gets worse and worse. Such a situation in an organization leads to violation of social or organizational rules, and at the worst case it suffers from serious accidents or scandals. Therefore, it is important for organizational managers to make efforts and take measures to enhance cooperative behaviors. Although there seem to be many ways to constantly elicit cooperative behaviors, the punishment is one of the most effective measures for enhancing cooperation. This study focused on the effects of penalty and probability of the revelation of defection on the cooperation, and getting insight into how punishment strategy should be used to get rid of social dilemmas and enhance cooperation. This study conducted a simulation experiment to find the proper penal regulations condition that can suppress violations （defective behavior） in a 2-person prisoner＇s dilemma situation. The effects of probability of the revelation of defection and penalty to revelation on the cooperative behavior were identified with the interactive effect of both experimental factors. The defection （uncooperative behavior） decreased when the penalty to the defection was heavy and the probability of the revelation of defection was low than that when the penalty to the defection was light and the probability of the revelation of the defection was high.
文摘T he residual stray magnetic fields present in ferromagnetic casting slabs were investigated in this work,which result from the magnetic fields generated during the steel casting process.Existing optical detection methods face challenges owing to surface oxide scales,and conventional high-precision magnetic sensors are ineffective at high temperatures.To overcome these limitations,a small coil sensor was employed to measure the residual magnetism strength in oscillation traces,using metal magnetic memory and electromagnetic induction methods,which can carry out detection without an external excitation source.Using this technology,the proposed scheme successfully detects defects at high tempe-ratures(up to 670℃)without a cooling device.The key findings include the ability to detect both surface and near-surface defects,such as cracks and oscillation marks,with an enhanced signal-to-noise ratio(SNR)of 7.2 dB after signal processing.The method’s practicality was validated in a steel mill environment,where testing on casting slabs effectively detected defects,providing a foundation for improving industrial quality control.The proposed detection scheme offers a significant advancement in nondestructive testing(NDT)for high-temperature applications,contributing to more efficient and accurate monitoring of ferromagnetic material integrity.
文摘Biomass-derived carbon materials are favored for their abundance and sustainability,and ease of preparation and modification.By surface activation and modification they can have a good electrical conductivity,excellent catalytic activity,a remarkable adsorption capacity,and different interfacial physicochemical functionalities.Surface-modified biochars have found wide applications in energy storage,environmental remediation,and catalysis.However,achieving precise and controllable modification of their active sites remains a challenge.Recent advances and future prospects for controlling their surface morphology,defect engineering,and surface coating strategies,with particular attention to their means of fabrication,are reviewed.
基金supported by the National Natural Science Foundation of China(Grant No.62205103)the Natural Science Foundation of Hunan Province(Grant No.2023JJ40216)the Elite Youth Program by the Department of Education of Hunan Province(Grant No.24B0663)。
文摘Although the certified power conversion efficiency(PCE)of single-junction perovskite solar cells(PSCs)has achieved a high level of 27%,approaching the single-crystalline silicon solar cells,the device stability remains an urgent issue to be resolved for the commercialization.Defect passivation emerged as a viable approach to enhance the operational stability of the solar devices.Herein,phenylthiourea(PhTu)derivatives are selected as effective passivation agents to enhance the optoelectronic properties of printed methylammonium lead iodide(MAPbI_(3))films.It is demonstrated that incorporating a small amount of 1-(4-carboxyphenyl)-2-thiourea(PhTu-COOH)significantly reduces the trap-state density and leads to longer carrier lifetime of the perovskite films.As a result,the inverted solar device made of Ph Tu-COOH-modified MAPbI_(3) perovskite film shows remarkably improved efficiency(from 17.29%to 20.22%)and obviously increased open-circuit voltage(V_(OC))(from 1.043 to 1.143 V),as compared with the pristine device.Moreover,the Ph Tu-COOH-modified PSCs exhibit enhanced operational stability due to the significantly reduced trap-state density.Finally,the optimized solar module fabricated with an active area of 11.28 cm^(2) delivers a high PCE of 17.07%with negligible V_(OC)loss,demonstrating the feasibility of the blade-coating method for large-area perovskite film deposition.
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the National Natural Science Foundation of China(Nos.62374029,22175029,62474033,and W2433038)the Young Elite Scientists Sponsorship Program by CAST(No.YESS20220550)+2 种基金the Sichuan Science and Technology Program(No.2024NSFSC0250)the Natural Science Foundation of Shenzhen Innovation Committee(JCYJ20210324135614040)the Fundamental Research Funds for the Central Universities of China(No.ZYGX2022J032).
文摘Perovskite solar cells(PSCs)have emerged as promising photovoltaic technologies owing to their remarkable power conversion efficiency(PCE).However,heat accumulation under continuous illumination remains a critical bottleneck,severely affecting device stability and long-term operational performance.Herein,we present a multifunctional strategy by incorporating highly thermally conductive Ti_(3)C_(2)T_(X) MXene nanosheets into the perovskite layer to simultaneously enhance thermal management and optoelectronic properties.The Ti_(3)C_(2)T_(X) nanosheets,embedded at perovskite grain boundaries,construct efficient thermal conduction pathways,significantly improving the thermal conductivity and diffusivity of the film.This leads to a notable reduction in the device’s steady-state operating temperature from 42.96 to 39.97 under 100 mW cm^(−2) illumination,thereby alleviating heat-induced performance degradation.Beyond thermal regulation,Ti_(3)C_(2)T_(X),with high conductivity and negatively charged surface terminations,also serves as an effective defect passivation agent,reducing trap-assisted recombination,while simultaneously facilitating charge extraction and transport by optimizing interfacial energy alignment.As a result,the Ti_(3)C_(2)T_(X)-modified PSC achieve a champion PCE of 25.13%and exhibit outstanding thermal stability,retaining 80%of the initial PCE after 500 h of thermal aging at 85 and 30±5%relative humidity.(In contrast,control PSC retain only 58%after 200 h.)Moreover,under continuous maximum power point tracking in N2 atmosphere,Ti_(3)C_(2)T_(X)-modified PSC retained 70%of the initial PCE after 500 h,whereas the control PSC drop sharply to 20%.These findings highlight the synergistic role of Ti_(3)C_(2)T_(X) in thermal management and optoelectronic performance,paving the way for the development of high-efficiency and heat-resistant perovskite photovoltaics.
基金financially supported by the supported by Shandong Provincial Natural Science Foundation(ZR2024MB108)Taishan Young Scholar Program(tsqn202312312)Excellent Young Scholars of the Shandong Provincial Natural Science Foundation(Overseas)(2023HWYQ-112)。
文摘Conversion-type electrode materials hold significant promise for potassium-ion batteries(PIBs)due to their high theoretical capacities,yet their practical deployment is hindered by sluggish kinetics and irreversible structural degradation.To overcome these limitations,we propose a rationally engineered nanoreactor architecture that stabilizes defect-rich MoS_(2)via interlayer incorporation of a carbon monolayer,followed by encapsulation within a nitrogen-doped carbon shell,forming a MoSSe@NC heterostructure.This tailored structure synergistically accelerates both K^(+)diffusion kinetics and electron transfer,enabling unprecedented rate performance(107 mAh g^(-1)at 10 Ag^(-1))and ultralong cyclability(86.5%capacity retention after 1200 cycles at 3 A g^(-1)).Mechanistic insights reveal a distinctive“adsorption-conversion”pathway,where sulfur vacancies on exposed S-Mo-S basal planes act as preferential K^(+)adsorption sites,effectively suppressing parasitic phase transitions during intercalation.In situ X-ray diffraction and transmission electron microscopy corroborate the structural reversibility of the conversion reaction,with the carbon matrix dynamically accommodating strain while preserving electrode integrity.This work not only advances the understanding of defect-driven interfacial chemistry in conversion-type materials but also provides a versatile strategy for designing high-performance anodes in next-generation PIBs through heterostructure engineering.
基金supported by the Jilin Science and Technology Development Plan (20240101029JJ) for the following study:synchronized high-speed detection of surface shape and defects in the grinding stage of complex surfaces (KLMSZZ202305)for the high-precision wide dynamic large aperture optical inspection system for fine astronomical observation by the National Major Research Instrument Development Project (62127901)+2 种基金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 National Natural Science Foundation of China(Grant Nos.42525201,42230710,42407521).
文摘Soil desiccation cracking is a prevalent natural phenomenon that poses significant geotechnical and geoenvironmental challenges.Cracks typically initiate at surface defects such as air bubbles,large aggregates,tiny pits,or uneven surfaces,where localized stress concentrations are readily induced.This study conducted a series of laboratory desiccation tests on slurry samples to investigate the initiation and propagation of desiccation cracks in the presence of varying types and quantities of surface defects.Digital image correlation(DIC)technology was employed to monitor the strain and displacement fields on the soil surface during the desiccation process.The results reveal that strain and displacement data derived from DIC can precisely predict the initiation sites and propagation directions of desiccation cracks.In samples with internal defects,cracks predominantly propagate through the defect,whereas external defects tend to initiate cracks along their edges.In samples with multiple defects,Y-shaped crack patterns generally form initially,followed by T-shaped and straight cracks,driven by the evolving stress field.The dynamic interplay between crack formation and tensile stress redistribution governs the initiation and propagation of desiccation cracks.
基金supported by the National Natural Science Foundation of China(No.52274346).
文摘Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphite.This study utilizes the porous“defect advantage”of a cathode carbon block matrix to prepare silicon-doped and asphalt-coated detoxified and purified waste graphitization cathode carbon blocks for use as high-performance silicon/carbon composite anode materials.The results show that the uniformly silicondoped silicon/carbon composite material features a unique amorphous carbon-encapsulated“locked silicon”structure,which effectively addresses issues such as cathode volume expansion,excessive growth of the solid electrolyte interphase(SEI)film,and poor electrical contact between active materials.Consequently,electrochemical performance is enhanced.After assembly in a half-cell,the PSCC/10%Si@C(purified waste graphitization cathode carbon/10%Si@C)material exhibits optimal electrochemical stability,with an initial charging specific capacity of 514.5 mAh/g at 0.1 C(1 C=170 mA/g)and a capacity retention rate of 95.1%after 100 cycles.At a charge rate of 2.0 C,a specific capacity of 216.9 mAh/g is achieved.This technology provides a new pathway for the economical and high-value utilization of waste cathode carbon blocks and the development of low-cost,high-performance anode materials.
基金supported by the National Institute on Aging(Nos.AG000723 and AG000578)(to VAB)the Fondation Sante(No.19656),Greece 2.0+1 种基金the National Recovery and Resilience Plan’s flagship program TAEDR-0535850the European Research Council(No.101077374-Synapto Mitophagy)(to KP)。
文摘N umerous neurological disorders negatively impact the nervous system,either through loss of neurons or by disrupting the normal functioning of neural networks.These impairments manifest as cognitive defects,memory loss,behavioral abnormalities,and motor dysfunctions.Decades of research have significantly advanced our understanding of the pathophysiology underlying neurodegene rative diseases,including Alzheimer's disease(AD),Parkinson's disease,amyotrophic lateral sclerosis,and others.
基金supported by a grant from the Beijing Union Medical College Foundation-Rui E Emergency Medicine Research Fund in 2025。
文摘Central venous catheterization(CVC)is a fundamental clinical procedure widely performed across medical specialties.However,the complication rate of subclavian vein catheterization ranges from 6%to 11%.[1]Common complications include hemothorax,pneumothorax,air embolism,arterial puncture,and aortic perforation.[2]Herein,we report a rare case of accidental puncture of the aorta during subclavian CVC,which was successfully managed with a ventricular septal defect(VSD)occluder.
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.
文摘Perovskite quantum dot light-emitting diodes(Pe-QLEDs)have shown immense application potential in display and lighting fields due to their narrow full-width at half maximum(FWHM)and high photoluminescence quantum yield(PLQY).Despite significant advancements in their performance,challenges such as defects and ion migration still hinder their long-term stability and operational efficiency.To address these issues,various optimization strategies,including ligand engineering,interface passivation,and self-assembly strategy,are being actively researched.This review focuses on the synthesis methods,challenges and optimization of perovskite quantum dots,which are critical for the commercialization and large-scale production of high-performance and stable Pe-QLEDs.
