AgCrSe2-based compounds have attracted much attention as an environmentally friendly thermoelectric material in recent years due to the intriguing liquid-like properties.However,the ultra-low carrier concentration and...AgCrSe2-based compounds have attracted much attention as an environmentally friendly thermoelectric material in recent years due to the intriguing liquid-like properties.However,the ultra-low carrier concentration and the high Ag_(Cr)deep-level defects limit the overall thermoelectric performance.Here,we successfully introduced Pb into Ag-deficient Ag_(0.97)CrSe_(2) alloys to tune the carrier concentration across a broad temperature range.The Pb^(2+) as an acceptor dopant preferentially occupies Cr sites,boosting the hole carrier concentration to 1.77×10^(19) cm^(-3) at room temperature.Furthermore,the Pb strongly inhibits the creation of intrinsic Ag_(Cr) defects,weakens the increased thermal excited ionization with the increasing temperature and slowed the rising trend of the carrier concentration.The designed carrier concentration matches the theoretically predicted optimized one over the entire temperature range,leading to a remarkable enhancement in power factor,especially the maximum power factor of ~500 μW·m^(-1)·K^(-2) at 750 K is superior to most previous results.Additionally,the abundant point defects promote phonon scattering,thus reducing the lattice thermal conductivity.As a result,the maximum figure of merit zT(~0.51 at 750 K) is achieved in Ag_(0.97)Cr_(0.995)Pb_(0.005)Se_(2).This work confirms the feasibility of manipulating deep-level defects to achieve temperature-dependent optimal carrier concentration and provides a valuable guidance for other thermoelectric materials.展开更多
Defect engineering is pivotal in comprehending physical mechanisms that govern carrier transport and device performance.The defect evolution and carrier manipulation in Sn-doped Ga_(2)O_(3)bulk crystals subjected to d...Defect engineering is pivotal in comprehending physical mechanisms that govern carrier transport and device performance.The defect evolution and carrier manipulation in Sn-doped Ga_(2)O_(3)bulk crystals subjected to different thermal treatments were investigated,utilizing depth-profiled deep-level transient spectroscopy(DLTS)and frequency-dependent capacitance-voltage(C-V-f)techniques.In untreated Sn-doped Ga_(2)O_(3)with an electron concentration of 6.37×10^(17)cm^(−3),two dominant electron traps,E_(T1)(E_(C)−0.68 eV)and E_(T2)(E_(C)−0.76 eV),were identified,corresponding to gallium vacancy(V_(Ga))and the neutral complex of V_(Ga)-V_(O),respectively,and characterized as bulk traps.Fe Ga-related defects,E_(T3)(E_(C)−0.84 eV),were concentrated near surface.Nitrogen annealing significantly reduced E_(T1),increased E_(T2)density from 6.13×10^(15)to 1.1×10^(16)cm^(−3),and raised the interfacial state density(D_(it))to 3.36×10^(15)eV^(−1)cm^(−2),accompanied by an elevated electron concentration of 7.48×10^(18)cm^(−3).In contrast,air annealing enhanced E_(T1),with a density of 1.42×10^(16)cm^(−3),suppressed of E_(T2)/E_(T3)traps,resulting in a lower D_(it)of 1.74×10^(14)eV^(−1)cm^(−2),and a reduced electron concentration to 3.01×10^(16)cm^(−3).The findings reveal that a reducing environment induces V_(O)formation and converts discrete V_(Ga)acceptors into neutral V_(Ga)-V_(O)complexes,leading to downward surface band bending and electron accumulation.Conversely,V_(Ga)-V_(O)complexes are dissociated into V_(Ga)acceptors in oxidizing conditions,leading to an upward surface band bending and electron compensation.This work underscores the carrier concentration manipulation by defect engineering in Ga_(2)O_(3),offering insights essential for developing high-performance gallium oxide electronics.展开更多
Manual inspection of onba earing casting defects is not realistic and unreliable,particularly in the case of some micro-level anomalies which lead to major defects on a large scale.To address these challenges,we propo...Manual inspection of onba earing casting defects is not realistic and unreliable,particularly in the case of some micro-level anomalies which lead to major defects on a large scale.To address these challenges,we propose BearFusionNet,an attention-based deep learning architecture with multi-stream,which merges both DenseNet201 and MobileNetV2 for feature extraction with a classification head inspired by VGG19.This hybrid design,figuratively beaming from one layer to another,extracts the enormity of representations on different scales,backed by a prepreprocessing pipeline that brings defect saliency to the fore through contrast adjustment,denoising,and edge detection.The use of multi-head self-attention enhances feature fusion,enabling the model to capture both large and small spatial features.BearFusionNet achieves an accuracy of 99.66%and Cohen’s kappa score of 0.9929 in Kaggle’s Real-life Industrial Casting Defects dataset.Both McNemar’s and Wilcoxon signed-rank statistical tests,as well as fivefold cross-validation,are employed to assess the robustness of our proposed model.To interpret the model,we adopt Grad-Cam visualizations,which are the state of the art standard.Furthermore,we deploy BearFusionNet as a webbased system for near real-time inference(5-6 s per prediction),which enables the quickest yet accurate detection with visual explanations.Overall,BearFusionNet is an interpretable,accurate,and deployable solution that can automatically detect casting defects,leading to significant advances in the innovative industrial environment.展开更多
The original online version of this article was revised:The layout update for Article 758 has impacted the page range in the published issue,but did not affect the scholarly content.To ensure consistency with the orig...The original online version of this article was revised:The layout update for Article 758 has impacted the page range in the published issue,but did not affect the scholarly content.To ensure consistency with the originally assigned pages(2595-2614),we will need to publish an erratum to correct the article and restore the original page range.The original article has been corrected.展开更多
With the rapid development of transportation infrastructure,ensuring road safety through timely and accurate highway inspection has become increasingly critical.Traditional manual inspection methods are not only time-...With the rapid development of transportation infrastructure,ensuring road safety through timely and accurate highway inspection has become increasingly critical.Traditional manual inspection methods are not only time-consuming and labor-intensive,but they also struggle to provide consistent,high-precision detection and realtime monitoring of pavement surface defects.To overcome these limitations,we propose an Automatic Recognition of PavementDefect(ARPD)algorithm,which leverages unmanned aerial vehicle(UAV)-based aerial imagery to automate the inspection process.The ARPD framework incorporates a backbone network based on the Selective State Space Model(S3M),which is designed to capture long-range temporal dependencies.This enables effective modeling of dynamic correlations among redundant and often repetitive structures commonly found in road imagery.Furthermore,a neck structure based on Semantics and Detail Infusion(SDI)is introduced to guide cross-scale feature fusion.The SDI module enhances the integration of low-level spatial details with high-level semantic cues,thereby improving feature expressiveness and defect localization accuracy.Experimental evaluations demonstrate that theARPDalgorithm achieves a mean average precision(mAP)of 86.1%on a custom-labeled pavement defect dataset,outperforming the state-of-the-art YOLOv11 segmentation model.The algorithm also maintains strong generalization ability on public datasets.These results confirm that ARPD is well-suited for diverse real-world applications in intelligent,large-scale highway defect monitoring and maintenance planning.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
The current technical standards primarily relied on experience to judge the interfacial bonding properties between the self-compacting concrete filling layer and the steam-cured concrete precast slab in CRTS Ⅲ slab b...The current technical standards primarily relied on experience to judge the interfacial bonding properties between the self-compacting concrete filling layer and the steam-cured concrete precast slab in CRTS Ⅲ slab ballastless track structure.This study sought to enhance technical standards for evaluating interfacial bonding properties by suggesting the use of the splitting tensile strength to evaluate the impact of bubble defects.Specimens were fabricated through on-site experiment.The percent of each area of 6 cm^(2)or more bubble defect was 0 in most of specimens.When the cumulative area of all bub-ble defects reached 12%,the splitting tensile strength value was 0.67 MPa,which exceeded the minimum required value of 0.5 MPa for ensuring bonding interface adhesion.Furthermore,when the cumulative area of all bubble defects reached 8%,the splitting tensile strength value was 0.85 MPa,which exceeded the minimum required value of 0.8 MPa,thereby over-coming the negative impact of each area of 10 cm^(2) or more bubble defect.Additionally,keeping the cumulative area of each area of 6 cm^(2) or more bubble defect below 6%ensured adequate bonding strength and reduced the occurrence of specimens with lower splitting tensile strength values.展开更多
The deep-level defects of Cd Zn Te（CZT）crystals grown by the modified vertical Bridgman（MVB）method act as trapping centers or recombination centers in the band gap,which have significant effects on its electrical ...The deep-level defects of Cd Zn Te（CZT）crystals grown by the modified vertical Bridgman（MVB）method act as trapping centers or recombination centers in the band gap,which have significant effects on its electrical properties.The resistivity and electron mobility–lifetime product of high resistivity Cd（0.9）Zn（0.1）Te wafer marked CZT1 and low resistivity Cd（0.9）Zn（0.1）Te wafer marked CZT2 were tested respectively.Their deep-level defects were identified by thermally stimulated current（TSC）spectroscopy and thermoelectric effect spectroscopy（TEES）respectively.Then the trap-related parameters were characterized by the simultaneous multiple peak analysis（SIMPA）method.The deep donor level（EDD/dominating dark current was calculated by the relationship between dark current and temperature.The Fermi-level was characterized by current–voltage measurements of temperature dependence.The width of the band gap was characterized by ultraviolet-visible-infrared transmittance spectroscopy.The results show the traps concentration and capture cross section of CZT1 are lower than CZT2,so its electron mobility–lifetime product is greater than CZT2.The Fermi-level of CZT1 is closer to the middle gap than CZT2.The degree of Fermi-level pinned by EDDof CZT1 is larger than CZT2.It can be concluded that the resistivity of CZT crystals increases as the degree of Fermi-level pinned near the middle gap by the deep donor level enlarges.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
Infectious bone defects represent a substantial challenge in clinical practice,necessitating the deployment of advanced therapeutic strategies.This study presents a treatment modality that merges a mild photothermal t...Infectious bone defects represent a substantial challenge in clinical practice,necessitating the deployment of advanced therapeutic strategies.This study presents a treatment modality that merges a mild photothermal therapy hydrogel with a pulsed drug delivery mechanism.The system is predicated on a hydrogel matrix that is thermally responsive,characteristic of bone defect sites,facilitating controlled and site-specific drug release.The cornerstone of this system is the incorporation of mild photothermal nanoparticles,which are activated within the temperature range of 40–43°C,thereby enhancing the precision and efficacy of drug delivery.Our findings demonstrate that the photothermal response significantly augments the localized delivery of therapeutic agents,mitigating systemic side effects and bolstering efficacy at the defect site.The synchronized pulsed release,cooperated with mild photothermal therapy,effectively addresses infection control,and promotes bone regeneration.This approach signifies a considerable advancement in the management of infectious bone defects,offering an effective and patient-centric alternative to traditional methods.Our research endeavors to extend its applicability to a wider spectrum of tissue regeneration scenarios,underscoring its transformative potential in the realm of regenerative medicine.展开更多
In integrated circuit(IC)manufacturing,fast,nondestructive,and precise detection of defects in patterned wafers,realized by bright-field microscopy,is one of the critical factors for ensuring the final performance and...In integrated circuit(IC)manufacturing,fast,nondestructive,and precise detection of defects in patterned wafers,realized by bright-field microscopy,is one of the critical factors for ensuring the final performance and yields of chips.With the critical dimensions of IC nanostructures continuing to shrink,directly imaging or classifying deep-subwavelength defects by bright-field microscopy is challenging due to the well-known diffraction barrier,the weak scattering effect,and the faint correlation between the scattering cross-section and the defect morphology.Herein,we propose an optical far-field inspection method based on the form-birefringence scattering imaging of the defective nanostructure,which can identify and classify various defects without requiring optical super-resolution.The technique is built upon the principle of breaking the optical form birefringence of the original periodic nanostructures by the defect perturbation under the anisotropic illumination modes,such as the orthogonally polarized plane waves,then combined with the high-order difference of far-field images.We validated the feasibility and effectiveness of the proposed method in detecting deep subwavelength defects through rigid vector imaging modeling and optical detection experiments of various defective nanostructures based on polarization microscopy.On this basis,an intelligent classification algorithm for typical patterned defects based on a dual-channel AlexNet neural network has been proposed,stabilizing the classification accuracy ofλ/16-sized defects with highly similar features at more than 90%.The strong classification capability of the two-channel network on typical patterned defects can be attributed to the high-order difference image and its transverse gradient being used as the network’s input,which highlights the polarization modulation difference between different patterned defects more significantly than conventional bright-field microscopy results.This work will provide a new but easy-to-operate method for detecting and classifying deep-subwavelength defects in patterned wafers or photomasks,which thus endows current online inspection equipment with more missions in advanced IC manufacturing.展开更多
Phenanthrene(Phe)is one of the common polycyclic aromatic hydrocarbons in the environment,and recent studies show that it can cause cardiac developmental toxicity and immunotoxicity.However,it is still unknown whether...Phenanthrene(Phe)is one of the common polycyclic aromatic hydrocarbons in the environment,and recent studies show that it can cause cardiac developmental toxicity and immunotoxicity.However,it is still unknown whether it can affect the hematopoietic development in aquatic organisms.To address this question,zebrafish(Danio rerio)were chronically exposed to Phe at different concentrations.We found that Phe caused structural damage to the renal tubules in the kidney,induced malformed erythrocytes in peripheral blood,and decreased the proportion of myeloid cells in adult zebrafish,suggesting possible negative impacts that Phe posed to hematopoietic development.Then,using in situ hybridization technology,we found that Phe decreased the expression of primitive hematopoietic marker genes,specifically gata1 and pu.1,accompanied by an obstruction of primitive erythrocyte circulation.Furthermore,Phe impaired definitive hematopoiesis,increased aberrations of the transient hematopoietic site(PBI),and reduced the generation of hematopoietic stem cells,ultimately influencing the number of erythrocytes and myeloid cells.The findings suggested that Phe could induce hematopoietic toxicity in zebrafish embryos and pose unknown ecological risks.展开更多
The rapid progress in the construction of heavy-haul and high-speed railways has led to a surge in rail defects and unforeseen failures.Addressing this issue necessitates the implementation of more sophisticated rail ...The rapid progress in the construction of heavy-haul and high-speed railways has led to a surge in rail defects and unforeseen failures.Addressing this issue necessitates the implementation of more sophisticated rail inspection methods,specifically involving real-time,precise detection,and assessment of rail defects.Current applications fail to address the evolving requirements,prompting the need for advancements.This paper provides a summary of various types of rail defects and outlines both traditional and innovative non-destructive inspection techniques,examining their fundamental features,benefits,drawbacks,and practical suitability for railway track inspection.It also explores potential enhancements to equipment and software.The comprehensive review draws upon pertinent international research and review papers.Furthermore,the paper introduces a fusion of inspection methods aimed at enhancing the overall reliability of defect detection.展开更多
As the global population ages,osteoporotic bone fractures leading to bone defects are increasingly becoming a significant challenge in the field of public health.Treating this disease faces many challenges,especially ...As the global population ages,osteoporotic bone fractures leading to bone defects are increasingly becoming a significant challenge in the field of public health.Treating this disease faces many challenges,especially in the context of an imbalance between osteoblast and osteoclast activities.Therefore,the development of new biomaterials has become the key.This article reviews various design strategies and their advantages and disadvantages for biomaterials aimed at osteoporotic bone defects.Overall,current research progress indicates that innovative design,functionalization,and targeting of materials can significantly enhance bone regeneration under osteoporotic conditions.By comprehensively considering biocompatibility,mechanical properties,and bioactivity,these biomaterials can be further optimized,offering a range of choices and strategies for the repair of osteoporotic bone defects.展开更多
Achieving high-quality perovskite films without surface defects is regarded as a crucial target for the development of durable high-performance perovskite solar cells.Additive engineering is commonly employed to simul...Achieving high-quality perovskite films without surface defects is regarded as a crucial target for the development of durable high-performance perovskite solar cells.Additive engineering is commonly employed to simultaneously control the growth of perovskite crystals and passivate defects.Here,4-(trifluoromethyl)benzoic anhydride(4-TBA)composed of benzene rings functionalized with carbonyl and trifluoromethyl groups was used as an example additive to study the characteristics of additives used for producing high-quality perovskites and controlling their surface properties.The interaction between4-TBA and perovskite precursor materials was investigated using density functional theory(DFT)simulations.The electron-rich carbonyl group efficiently passivated the under-coordinated lead-ion defects.Additionally,hydrogen bonding between trifluoromethyl and organic cations prevents the generation of cation vacancies.Because of its intrinsic hydrophobicity,the trifluoromethyl group simultaneously improves the moisture and heat stability of the film.4-TBA serves as a universal modifier for various perovskite compositions.The power conversion efficiency(PCE)of inverted perovskite solar cells(PSCs)based on methylammonium(MA)with 4-TBA was improved from 16.15%to 19.28%.Similarly,the PCE of inverted PSCs based on a cesium formamidinium MA(CsFAMA)perovskite film increased from20.72%to 23.58%,upon addition of 4-TBA.Furthermore,the moisture and thermal stability of 4-TBAtreated films and devices was significantly enhanced,along with prolonged device performance.Our work provides guidance on selecting the structure and functional groups that are essential for surface defect passivation and the production of high-quality perovskites.展开更多
To solve the problem of low detection accuracy for complex weld defects,the paper proposes a weld defects detection method based on improved YOLOv5s.To enhance the ability to focus on key information in feature maps,t...To solve the problem of low detection accuracy for complex weld defects,the paper proposes a weld defects detection method based on improved YOLOv5s.To enhance the ability to focus on key information in feature maps,the scSE attention mechanism is intro-duced into the backbone network of YOLOv5s.A Fusion-Block module and additional layers are added to the neck network of YOLOv5s to improve the effect of feature fusion,which is to meet the needs of complex object detection.To reduce the computation-al complexity of the model,the C3Ghost module is used to replace the CSP2_1 module in the neck network of YOLOv5s.The scSE-ASFF module is constructed and inserted between the neck network and the prediction end,which is to realize the fusion of features between the different layers.To address the issue of imbalanced sample quality in the dataset and improve the regression speed and accuracy of the loss function,the CIoU loss function in the YOLOv5s model is replaced with the Focal-EIoU loss function.Finally,ex-periments are conducted based on the collected weld defect dataset to verify the feasibility of the improved YOLOv5s for weld defects detection.The experimental results show that the precision and mAP of the improved YOLOv5s in detecting complex weld defects are as high as 83.4%and 76.1%,respectively,which are 2.5%and 7.6%higher than the traditional YOLOv5s model.The proposed weld defects detection method based on the improved YOLOv5s in this paper can effectively solve the problem of low weld defects detection accuracy.展开更多
Solar cell defects exhibit significant variations and multiple types,with some defect data being difficult to acquire or having small scales,posing challenges in terms of small sample and small target in defect detect...Solar cell defects exhibit significant variations and multiple types,with some defect data being difficult to acquire or having small scales,posing challenges in terms of small sample and small target in defect detection for solar cells.In order to address this issue,this paper proposes a multi-step approach for detecting the complex defects of solar cells.First,individual cell plates are extracted from electroluminescence images for block-by-block detection.Then,StyleGAN2-Ada is utilized for generative adversarial networks data augmentation to expand the number of defect samples in small sample defects.Finally,the fake dataset is combined with real dataset,and the improved YOLOv5 model is trained on this mixed dataset.Experimental results demonstrate that the proposed method achieves a superior performance in detecting the defects with small sample and small target,with the final recall rate reaching 99.7%,an increase of 3.9% compared with the unimproved model.Additionally,the precision and mean average precision are increased by 3.4% and 3.5%,respectively.Moreover,the experiments demonstrate that the improved network training on the mixed dataset can effectively enhance the detection performance of the model.The combination of these approaches significantly improves the network’s ability to detect solar cell defects.展开更多
Ductile iron pipes,a staple in global urban water supply systems,face a significant challenge in the form of corrosion,which threatens water quality and pipeline integrity.The deterioration mechanism of shrink-age def...Ductile iron pipes,a staple in global urban water supply systems,face a significant challenge in the form of corrosion,which threatens water quality and pipeline integrity.The deterioration mechanism of shrink-age defects on the passivation behavior of ductile iron in simulated concrete pore solution was investi-gated.The results indicated that shrinkage defects increase donor density and reduce the threshold value of chlorine concentration for rupture of ductile iron passion film(CTV)of ductile iron.Defects reduce CTV from 1-1.1 wt.%to 0.36-0.4 wt.%.Because the matrix/graphite around the defect has a higher Volta potential difference,the shrinkage defect preferentially corrodes and induces local corrosion of the sur-rounding matrix,while no significant corrosion was observed in the region away from the defect.High lattice distortion and Si segregation around the shrinkage defect improve the driving force of corrosion in thermodynamics.Furthermore,shrinkage defects elevate the content of Fe(Ⅲ)compounds in the passive film,without compromising its duplex structure.These defects accelerate the nucleation and growth of the passive film,but generate more cation interstitials.This variation of chemical composition of passive film compromises the film’s integrity and protective properties,attributable to a potential mechanism of micro-environmental acidification and the synergistic effects of shrinkage defect-graphite-matrix multiple micro-galvanic couples.展开更多
The stability of perovskite solar cells(PSCs)is adversely affected by nonradiative recombination resulting from buried interface defects.Herein,we synthesize a polyionic liquid,poly(p-vinylbenzyl trimethylam-monium he...The stability of perovskite solar cells(PSCs)is adversely affected by nonradiative recombination resulting from buried interface defects.Herein,we synthesize a polyionic liquid,poly(p-vinylbenzyl trimethylam-monium hexafluorophosphate)(PTA),and introduce it into the buried interface of PSCs.The quaternary ammonium cation(N(-CH_(3))^(3+))in PTA can fill the vacancies of organic cations within the perovskite structure and reduce shallow energy level defects.Additionally,the hexafluorophosphate(PF6−)in PTA forms a Lewis acid-base interaction with Pb^(2+)in the perovskite layer,effectively passivating deep en-ergy level defects.Furthermore,hydrogen bonding can be established between organic cations and the PF6−anion,preventing the formation of shallow energy level defects.Through this synergistic mecha-nism,the deep and shallow energy level defects are effectively mitigated,resulting in improved device performance.As a result,the resulting treated inverted PSC exhibits an impressive power conversion ef-ficiency(PCE)of 24.72%.Notably,the PTA-treated PSCs exhibit remarkable stability,with 88.5%of the original PCE retained after undergoing heat aging at 85℃ for 1078 h,and 89.1%of the initial PCE main-tained following continuous exposure to light for 1100 h at the maximum power point.Synergistically suppressing multiple defects at the buried interface through the use of polyionic liquids is a promising way to improve the commercial viability of PSCs.展开更多
A comprehensive understanding of the relevance between molecular structure and passivation ability to screen efficient modifiers is essential for enhancing the performance of perovskite solar cells(PSCs).Here,three si...A comprehensive understanding of the relevance between molecular structure and passivation ability to screen efficient modifiers is essential for enhancing the performance of perovskite solar cells(PSCs).Here,three similarπ-πstacking molecules namely benzophenone(BPN),diphenyl sulfone(DPS),and diphenyl sulfoxide(DPSO)are used as back-interface modifiers in carbon-based CsPbBr_(3)PSCs.After investigation,the results demonstrate the positive effect of the p-πconjugation characteristic inπ-πstacking molecules on maximizing their passivation ability.The p-πco njugation of DPSO enables a higher coordinative activity of oxygen atom in its S=O group than that in 0=S=O group of DPS and C=O group of BPN,which gives a superior passivation effect of DPSO on defects of perovskite films.The modification of DPSO also significantly improves the p-type behavior of perovskite films and the back-interfacial energetics matching,inducing an increase of hole extraction and a decrease of energy loss.Finally,the unencapsulated carbon-based CsPbBr_(3)PSCs with DPSO achieve a maximum power conversion efficiency of 10.60%and outstanding long-term stability in high-temperature,high-humidity(85℃,85%relative humidity)air environment.This work provides insights into the influence of the structure ofπ-πstacking molecules on their ability to improve the perovskite films quality and therefore the PSCs performance.展开更多
基金Project supported by the National Key Research and Development Program of China (Grant Nos. 2018YFA0702100and 2022YFB3803900)the Joint Funds of the National Natural Science Foundation of China and the Chinese Academy of Sciences (CAS)’ Large-Scale Scientific Facility (Grant No. U1932106)the Sichuan University Innovation Research Program of China (Grant No. 2020SCUNL112)。
文摘AgCrSe2-based compounds have attracted much attention as an environmentally friendly thermoelectric material in recent years due to the intriguing liquid-like properties.However,the ultra-low carrier concentration and the high Ag_(Cr)deep-level defects limit the overall thermoelectric performance.Here,we successfully introduced Pb into Ag-deficient Ag_(0.97)CrSe_(2) alloys to tune the carrier concentration across a broad temperature range.The Pb^(2+) as an acceptor dopant preferentially occupies Cr sites,boosting the hole carrier concentration to 1.77×10^(19) cm^(-3) at room temperature.Furthermore,the Pb strongly inhibits the creation of intrinsic Ag_(Cr) defects,weakens the increased thermal excited ionization with the increasing temperature and slowed the rising trend of the carrier concentration.The designed carrier concentration matches the theoretically predicted optimized one over the entire temperature range,leading to a remarkable enhancement in power factor,especially the maximum power factor of ~500 μW·m^(-1)·K^(-2) at 750 K is superior to most previous results.Additionally,the abundant point defects promote phonon scattering,thus reducing the lattice thermal conductivity.As a result,the maximum figure of merit zT(~0.51 at 750 K) is achieved in Ag_(0.97)Cr_(0.995)Pb_(0.005)Se_(2).This work confirms the feasibility of manipulating deep-level defects to achieve temperature-dependent optimal carrier concentration and provides a valuable guidance for other thermoelectric materials.
基金supported by the National Key R&D Program of China(2022YFB3605403)the Provincial Science and Technology Major Project of Jiangsu(BG2024030)the National Natural Science Foundation of China(62425403,62234007,62293521,U21A20503,U21A2071,62004183).
文摘Defect engineering is pivotal in comprehending physical mechanisms that govern carrier transport and device performance.The defect evolution and carrier manipulation in Sn-doped Ga_(2)O_(3)bulk crystals subjected to different thermal treatments were investigated,utilizing depth-profiled deep-level transient spectroscopy(DLTS)and frequency-dependent capacitance-voltage(C-V-f)techniques.In untreated Sn-doped Ga_(2)O_(3)with an electron concentration of 6.37×10^(17)cm^(−3),two dominant electron traps,E_(T1)(E_(C)−0.68 eV)and E_(T2)(E_(C)−0.76 eV),were identified,corresponding to gallium vacancy(V_(Ga))and the neutral complex of V_(Ga)-V_(O),respectively,and characterized as bulk traps.Fe Ga-related defects,E_(T3)(E_(C)−0.84 eV),were concentrated near surface.Nitrogen annealing significantly reduced E_(T1),increased E_(T2)density from 6.13×10^(15)to 1.1×10^(16)cm^(−3),and raised the interfacial state density(D_(it))to 3.36×10^(15)eV^(−1)cm^(−2),accompanied by an elevated electron concentration of 7.48×10^(18)cm^(−3).In contrast,air annealing enhanced E_(T1),with a density of 1.42×10^(16)cm^(−3),suppressed of E_(T2)/E_(T3)traps,resulting in a lower D_(it)of 1.74×10^(14)eV^(−1)cm^(−2),and a reduced electron concentration to 3.01×10^(16)cm^(−3).The findings reveal that a reducing environment induces V_(O)formation and converts discrete V_(Ga)acceptors into neutral V_(Ga)-V_(O)complexes,leading to downward surface band bending and electron accumulation.Conversely,V_(Ga)-V_(O)complexes are dissociated into V_(Ga)acceptors in oxidizing conditions,leading to an upward surface band bending and electron compensation.This work underscores the carrier concentration manipulation by defect engineering in Ga_(2)O_(3),offering insights essential for developing high-performance gallium oxide electronics.
基金funded by Multimedia University,Cyberjaya,Selangor,Malaysia(Grant Number:PostDoc(MMUI/240029)).
文摘Manual inspection of onba earing casting defects is not realistic and unreliable,particularly in the case of some micro-level anomalies which lead to major defects on a large scale.To address these challenges,we propose BearFusionNet,an attention-based deep learning architecture with multi-stream,which merges both DenseNet201 and MobileNetV2 for feature extraction with a classification head inspired by VGG19.This hybrid design,figuratively beaming from one layer to another,extracts the enormity of representations on different scales,backed by a prepreprocessing pipeline that brings defect saliency to the fore through contrast adjustment,denoising,and edge detection.The use of multi-head self-attention enhances feature fusion,enabling the model to capture both large and small spatial features.BearFusionNet achieves an accuracy of 99.66%and Cohen’s kappa score of 0.9929 in Kaggle’s Real-life Industrial Casting Defects dataset.Both McNemar’s and Wilcoxon signed-rank statistical tests,as well as fivefold cross-validation,are employed to assess the robustness of our proposed model.To interpret the model,we adopt Grad-Cam visualizations,which are the state of the art standard.Furthermore,we deploy BearFusionNet as a webbased system for near real-time inference(5-6 s per prediction),which enables the quickest yet accurate detection with visual explanations.Overall,BearFusionNet is an interpretable,accurate,and deployable solution that can automatically detect casting defects,leading to significant advances in the innovative industrial environment.
文摘The original online version of this article was revised:The layout update for Article 758 has impacted the page range in the published issue,but did not affect the scholarly content.To ensure consistency with the originally assigned pages(2595-2614),we will need to publish an erratum to correct the article and restore the original page range.The original article has been corrected.
基金supported in part by the Technical Service for the Development and Application of an Intelligent Visual Management Platformfor Expressway Construction Progress Based on BIM Technology(grant NO.JKYZLX-2023-09)in partby the Technical Service for the Development of an Early Warning Model in the Research and Application of Key Technologies for Tunnel Operation Safety Monitoring and Early Warning Based on Digital Twin(grant NO.JK-S02-ZNGS-202412-JISHU-FA-0035)sponsored by Yunnan Transportation Science Research Institute Co.,Ltd.
文摘With the rapid development of transportation infrastructure,ensuring road safety through timely and accurate highway inspection has become increasingly critical.Traditional manual inspection methods are not only time-consuming and labor-intensive,but they also struggle to provide consistent,high-precision detection and realtime monitoring of pavement surface defects.To overcome these limitations,we propose an Automatic Recognition of PavementDefect(ARPD)algorithm,which leverages unmanned aerial vehicle(UAV)-based aerial imagery to automate the inspection process.The ARPD framework incorporates a backbone network based on the Selective State Space Model(S3M),which is designed to capture long-range temporal dependencies.This enables effective modeling of dynamic correlations among redundant and often repetitive structures commonly found in road imagery.Furthermore,a neck structure based on Semantics and Detail Infusion(SDI)is introduced to guide cross-scale feature fusion.The SDI module enhances the integration of low-level spatial details with high-level semantic cues,thereby improving feature expressiveness and defect localization accuracy.Experimental evaluations demonstrate that theARPDalgorithm achieves a mean average precision(mAP)of 86.1%on a custom-labeled pavement defect dataset,outperforming the state-of-the-art YOLOv11 segmentation model.The algorithm also maintains strong generalization ability on public datasets.These results confirm that ARPD is well-suited for diverse real-world applications in intelligent,large-scale highway defect monitoring and maintenance planning.
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 a grant from China railway corporation science and technology research and development plan project(Grant No.2017G005-B)funding support by Wuyi University’s Hong Kong and Macao Joint Research and Development Fund(Grants No.2021WGALH15)funding support by the Innovation and Technology Commission of Hong Kong SAR Government to the Hong Kong Branch of National Rail Transit Electrification and Automation Engineering Technology Research Center(Grant No.K-BBY1).
文摘The current technical standards primarily relied on experience to judge the interfacial bonding properties between the self-compacting concrete filling layer and the steam-cured concrete precast slab in CRTS Ⅲ slab ballastless track structure.This study sought to enhance technical standards for evaluating interfacial bonding properties by suggesting the use of the splitting tensile strength to evaluate the impact of bubble defects.Specimens were fabricated through on-site experiment.The percent of each area of 6 cm^(2)or more bubble defect was 0 in most of specimens.When the cumulative area of all bub-ble defects reached 12%,the splitting tensile strength value was 0.67 MPa,which exceeded the minimum required value of 0.5 MPa for ensuring bonding interface adhesion.Furthermore,when the cumulative area of all bubble defects reached 8%,the splitting tensile strength value was 0.85 MPa,which exceeded the minimum required value of 0.8 MPa,thereby over-coming the negative impact of each area of 10 cm^(2) or more bubble defect.Additionally,keeping the cumulative area of each area of 6 cm^(2) or more bubble defect below 6%ensured adequate bonding strength and reduced the occurrence of specimens with lower splitting tensile strength values.
基金supported by the National Natural Science Foundation of China(No.51502234)the Scientific Research Plan Projects of Shaanxi Provincial Department of Education of China(No.15JS040)
文摘The deep-level defects of Cd Zn Te（CZT）crystals grown by the modified vertical Bridgman（MVB）method act as trapping centers or recombination centers in the band gap,which have significant effects on its electrical properties.The resistivity and electron mobility–lifetime product of high resistivity Cd（0.9）Zn（0.1）Te wafer marked CZT1 and low resistivity Cd（0.9）Zn（0.1）Te wafer marked CZT2 were tested respectively.Their deep-level defects were identified by thermally stimulated current（TSC）spectroscopy and thermoelectric effect spectroscopy（TEES）respectively.Then the trap-related parameters were characterized by the simultaneous multiple peak analysis（SIMPA）method.The deep donor level（EDD/dominating dark current was calculated by the relationship between dark current and temperature.The Fermi-level was characterized by current–voltage measurements of temperature dependence.The width of the band gap was characterized by ultraviolet-visible-infrared transmittance spectroscopy.The results show the traps concentration and capture cross section of CZT1 are lower than CZT2,so its electron mobility–lifetime product is greater than CZT2.The Fermi-level of CZT1 is closer to the middle gap than CZT2.The degree of Fermi-level pinned by EDDof CZT1 is larger than CZT2.It can be concluded that the resistivity of CZT crystals increases as the degree of Fermi-level pinned near the middle gap by the deep donor level enlarges.
文摘Based on inspection data,the authors analyze and summarize the main types and distribution characteristics of tunnel structural defects.These defects are classified into three types:surface defects,internal defects,and defects behind the structure.To address the need for rapid detection of different defect types,the current state of rapid detection technologies and equipment,both domestically and internationally,is systematically reviewed.The research reveals that surface defect detection technologies and equipment have developed rapidly in recent years.Notably,the integration of machine vision and laser scanning technologies have significantly improved detection efficiency and accuracy,achieving crack detection precision of up to 0.1 mm.However,the non-contact rapid detection of internal and behind-the-structure defects remains constrained by hardware limitations,with traditional detection remaining dominant.Nevertheless,phased array radar,ultrasonic,and acoustic vibration detection technologies have become research hotspots in recent years,offering promising directions for detecting these challenging defect types.Additionally,the application of multisensor fusion technology in rapid detection equipment has further enhanced detection capabilities.Devices such as cameras,3D laser scanners,infrared thermal imagers,and radar demonstrate significant advantages in rapid detection.Future research in tunnel inspection should prioritize breakthroughs in rapid detection technologies for internal and behind-the-structure defects.Efforts should also focus on developing multifunctional integrated detection vehicles that can simultaneously inspect both surface and internal structures.Furthermore,progress in fully automated,intelligent systems with precise defect identification and real-time reporting will be essential to significantly improve the efficiency and accuracy of tunnel inspection.
基金supported by the National Natural Science Foundation of China(32171354,82222015,82171001)The National Key Research and Development Program of China2023YFC2413600Research Funding from West China School/Hospital of Stomatology,Sichuan University(No.RCDWIS2023-1).
文摘Infectious bone defects represent a substantial challenge in clinical practice,necessitating the deployment of advanced therapeutic strategies.This study presents a treatment modality that merges a mild photothermal therapy hydrogel with a pulsed drug delivery mechanism.The system is predicated on a hydrogel matrix that is thermally responsive,characteristic of bone defect sites,facilitating controlled and site-specific drug release.The cornerstone of this system is the incorporation of mild photothermal nanoparticles,which are activated within the temperature range of 40–43°C,thereby enhancing the precision and efficacy of drug delivery.Our findings demonstrate that the photothermal response significantly augments the localized delivery of therapeutic agents,mitigating systemic side effects and bolstering efficacy at the defect site.The synchronized pulsed release,cooperated with mild photothermal therapy,effectively addresses infection control,and promotes bone regeneration.This approach signifies a considerable advancement in the management of infectious bone defects,offering an effective and patient-centric alternative to traditional methods.Our research endeavors to extend its applicability to a wider spectrum of tissue regeneration scenarios,underscoring its transformative potential in the realm of regenerative medicine.
基金funded by National Natural Science Foundation of China(Grant Nos.52130504,52305577,and 52175509)the Key Research and Development Plan of Hubei Province(Grant No.2022BAA013)+4 种基金the Major Program(JD)of Hubei Province(Grant No.2023BAA008-2)the Interdisciplinary Research Program of Huazhong University of Science and Technology(2023JCYJ047)the Innovation Project of Optics Valley Laboratory(Grant No.OVL2023PY003)the Postdoctoral Fellowship Program(Grade B)of China Postdoctoral Science Foundation(Grant No.GZB20230244)the fellowship from the China Postdoctoral Science Foundation(2024M750995)。
文摘In integrated circuit(IC)manufacturing,fast,nondestructive,and precise detection of defects in patterned wafers,realized by bright-field microscopy,is one of the critical factors for ensuring the final performance and yields of chips.With the critical dimensions of IC nanostructures continuing to shrink,directly imaging or classifying deep-subwavelength defects by bright-field microscopy is challenging due to the well-known diffraction barrier,the weak scattering effect,and the faint correlation between the scattering cross-section and the defect morphology.Herein,we propose an optical far-field inspection method based on the form-birefringence scattering imaging of the defective nanostructure,which can identify and classify various defects without requiring optical super-resolution.The technique is built upon the principle of breaking the optical form birefringence of the original periodic nanostructures by the defect perturbation under the anisotropic illumination modes,such as the orthogonally polarized plane waves,then combined with the high-order difference of far-field images.We validated the feasibility and effectiveness of the proposed method in detecting deep subwavelength defects through rigid vector imaging modeling and optical detection experiments of various defective nanostructures based on polarization microscopy.On this basis,an intelligent classification algorithm for typical patterned defects based on a dual-channel AlexNet neural network has been proposed,stabilizing the classification accuracy ofλ/16-sized defects with highly similar features at more than 90%.The strong classification capability of the two-channel network on typical patterned defects can be attributed to the high-order difference image and its transverse gradient being used as the network’s input,which highlights the polarization modulation difference between different patterned defects more significantly than conventional bright-field microscopy results.This work will provide a new but easy-to-operate method for detecting and classifying deep-subwavelength defects in patterned wafers or photomasks,which thus endows current online inspection equipment with more missions in advanced IC manufacturing.
基金supported by the National Natural Science Foundation of China(Nos.22276117 and 22076108)the Science and Technology Innovation Talent Team Project of Shanxi Province(No.202204051002024).
文摘Phenanthrene(Phe)is one of the common polycyclic aromatic hydrocarbons in the environment,and recent studies show that it can cause cardiac developmental toxicity and immunotoxicity.However,it is still unknown whether it can affect the hematopoietic development in aquatic organisms.To address this question,zebrafish(Danio rerio)were chronically exposed to Phe at different concentrations.We found that Phe caused structural damage to the renal tubules in the kidney,induced malformed erythrocytes in peripheral blood,and decreased the proportion of myeloid cells in adult zebrafish,suggesting possible negative impacts that Phe posed to hematopoietic development.Then,using in situ hybridization technology,we found that Phe decreased the expression of primitive hematopoietic marker genes,specifically gata1 and pu.1,accompanied by an obstruction of primitive erythrocyte circulation.Furthermore,Phe impaired definitive hematopoiesis,increased aberrations of the transient hematopoietic site(PBI),and reduced the generation of hematopoietic stem cells,ultimately influencing the number of erythrocytes and myeloid cells.The findings suggested that Phe could induce hematopoietic toxicity in zebrafish embryos and pose unknown ecological risks.
文摘The rapid progress in the construction of heavy-haul and high-speed railways has led to a surge in rail defects and unforeseen failures.Addressing this issue necessitates the implementation of more sophisticated rail inspection methods,specifically involving real-time,precise detection,and assessment of rail defects.Current applications fail to address the evolving requirements,prompting the need for advancements.This paper provides a summary of various types of rail defects and outlines both traditional and innovative non-destructive inspection techniques,examining their fundamental features,benefits,drawbacks,and practical suitability for railway track inspection.It also explores potential enhancements to equipment and software.The comprehensive review draws upon pertinent international research and review papers.Furthermore,the paper introduces a fusion of inspection methods aimed at enhancing the overall reliability of defect detection.
基金supported by the National Natural Science Foundation of China(Nos.82160419 and 82302772)Guizhou Basic Research Project(No.ZK[2023]General 201)。
文摘As the global population ages,osteoporotic bone fractures leading to bone defects are increasingly becoming a significant challenge in the field of public health.Treating this disease faces many challenges,especially in the context of an imbalance between osteoblast and osteoclast activities.Therefore,the development of new biomaterials has become the key.This article reviews various design strategies and their advantages and disadvantages for biomaterials aimed at osteoporotic bone defects.Overall,current research progress indicates that innovative design,functionalization,and targeting of materials can significantly enhance bone regeneration under osteoporotic conditions.By comprehensively considering biocompatibility,mechanical properties,and bioactivity,these biomaterials can be further optimized,offering a range of choices and strategies for the repair of osteoporotic bone defects.
基金supported by a Research Grant of Pukyong National University(2023)。
文摘Achieving high-quality perovskite films without surface defects is regarded as a crucial target for the development of durable high-performance perovskite solar cells.Additive engineering is commonly employed to simultaneously control the growth of perovskite crystals and passivate defects.Here,4-(trifluoromethyl)benzoic anhydride(4-TBA)composed of benzene rings functionalized with carbonyl and trifluoromethyl groups was used as an example additive to study the characteristics of additives used for producing high-quality perovskites and controlling their surface properties.The interaction between4-TBA and perovskite precursor materials was investigated using density functional theory(DFT)simulations.The electron-rich carbonyl group efficiently passivated the under-coordinated lead-ion defects.Additionally,hydrogen bonding between trifluoromethyl and organic cations prevents the generation of cation vacancies.Because of its intrinsic hydrophobicity,the trifluoromethyl group simultaneously improves the moisture and heat stability of the film.4-TBA serves as a universal modifier for various perovskite compositions.The power conversion efficiency(PCE)of inverted perovskite solar cells(PSCs)based on methylammonium(MA)with 4-TBA was improved from 16.15%to 19.28%.Similarly,the PCE of inverted PSCs based on a cesium formamidinium MA(CsFAMA)perovskite film increased from20.72%to 23.58%,upon addition of 4-TBA.Furthermore,the moisture and thermal stability of 4-TBAtreated films and devices was significantly enhanced,along with prolonged device performance.Our work provides guidance on selecting the structure and functional groups that are essential for surface defect passivation and the production of high-quality perovskites.
基金supported by Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX24_4084).
文摘To solve the problem of low detection accuracy for complex weld defects,the paper proposes a weld defects detection method based on improved YOLOv5s.To enhance the ability to focus on key information in feature maps,the scSE attention mechanism is intro-duced into the backbone network of YOLOv5s.A Fusion-Block module and additional layers are added to the neck network of YOLOv5s to improve the effect of feature fusion,which is to meet the needs of complex object detection.To reduce the computation-al complexity of the model,the C3Ghost module is used to replace the CSP2_1 module in the neck network of YOLOv5s.The scSE-ASFF module is constructed and inserted between the neck network and the prediction end,which is to realize the fusion of features between the different layers.To address the issue of imbalanced sample quality in the dataset and improve the regression speed and accuracy of the loss function,the CIoU loss function in the YOLOv5s model is replaced with the Focal-EIoU loss function.Finally,ex-periments are conducted based on the collected weld defect dataset to verify the feasibility of the improved YOLOv5s for weld defects detection.The experimental results show that the precision and mAP of the improved YOLOv5s in detecting complex weld defects are as high as 83.4%and 76.1%,respectively,which are 2.5%and 7.6%higher than the traditional YOLOv5s model.The proposed weld defects detection method based on the improved YOLOv5s in this paper can effectively solve the problem of low weld defects detection accuracy.
文摘Solar cell defects exhibit significant variations and multiple types,with some defect data being difficult to acquire or having small scales,posing challenges in terms of small sample and small target in defect detection for solar cells.In order to address this issue,this paper proposes a multi-step approach for detecting the complex defects of solar cells.First,individual cell plates are extracted from electroluminescence images for block-by-block detection.Then,StyleGAN2-Ada is utilized for generative adversarial networks data augmentation to expand the number of defect samples in small sample defects.Finally,the fake dataset is combined with real dataset,and the improved YOLOv5 model is trained on this mixed dataset.Experimental results demonstrate that the proposed method achieves a superior performance in detecting the defects with small sample and small target,with the final recall rate reaching 99.7%,an increase of 3.9% compared with the unimproved model.Additionally,the precision and mean average precision are increased by 3.4% and 3.5%,respectively.Moreover,the experiments demonstrate that the improved network training on the mixed dataset can effectively enhance the detection performance of the model.The combination of these approaches significantly improves the network’s ability to detect solar cell defects.
基金financially supported by the National Natural Science Foundation of China(Nos.52104319 and 52374323).
文摘Ductile iron pipes,a staple in global urban water supply systems,face a significant challenge in the form of corrosion,which threatens water quality and pipeline integrity.The deterioration mechanism of shrink-age defects on the passivation behavior of ductile iron in simulated concrete pore solution was investi-gated.The results indicated that shrinkage defects increase donor density and reduce the threshold value of chlorine concentration for rupture of ductile iron passion film(CTV)of ductile iron.Defects reduce CTV from 1-1.1 wt.%to 0.36-0.4 wt.%.Because the matrix/graphite around the defect has a higher Volta potential difference,the shrinkage defect preferentially corrodes and induces local corrosion of the sur-rounding matrix,while no significant corrosion was observed in the region away from the defect.High lattice distortion and Si segregation around the shrinkage defect improve the driving force of corrosion in thermodynamics.Furthermore,shrinkage defects elevate the content of Fe(Ⅲ)compounds in the passive film,without compromising its duplex structure.These defects accelerate the nucleation and growth of the passive film,but generate more cation interstitials.This variation of chemical composition of passive film compromises the film’s integrity and protective properties,attributable to a potential mechanism of micro-environmental acidification and the synergistic effects of shrinkage defect-graphite-matrix multiple micro-galvanic couples.
基金supported by the Science,Technology,and Innovation Commission of Shenzhen Municipality(No.GJHZ20220913143204008)the Shccig-Qinling Program(No.SMYJY202300294C)+3 种基金National Natural Science Foundation of China(Nos.22261142666,52372225,52172237,22305191)the Shaanxi Science Fund for Distinguished Young Scholars(No.2022JC-21)the Research Fund of the State Key Laboratory of Solidification Processing(NPU)China(No.2021-QZ-02).
文摘The stability of perovskite solar cells(PSCs)is adversely affected by nonradiative recombination resulting from buried interface defects.Herein,we synthesize a polyionic liquid,poly(p-vinylbenzyl trimethylam-monium hexafluorophosphate)(PTA),and introduce it into the buried interface of PSCs.The quaternary ammonium cation(N(-CH_(3))^(3+))in PTA can fill the vacancies of organic cations within the perovskite structure and reduce shallow energy level defects.Additionally,the hexafluorophosphate(PF6−)in PTA forms a Lewis acid-base interaction with Pb^(2+)in the perovskite layer,effectively passivating deep en-ergy level defects.Furthermore,hydrogen bonding can be established between organic cations and the PF6−anion,preventing the formation of shallow energy level defects.Through this synergistic mecha-nism,the deep and shallow energy level defects are effectively mitigated,resulting in improved device performance.As a result,the resulting treated inverted PSC exhibits an impressive power conversion ef-ficiency(PCE)of 24.72%.Notably,the PTA-treated PSCs exhibit remarkable stability,with 88.5%of the original PCE retained after undergoing heat aging at 85℃ for 1078 h,and 89.1%of the initial PCE main-tained following continuous exposure to light for 1100 h at the maximum power point.Synergistically suppressing multiple defects at the buried interface through the use of polyionic liquids is a promising way to improve the commercial viability of PSCs.
基金financial supports from the Natural Science Foundation of Shandong Province(ZR2021ME037)the National Natural Science Foundation of China(52472259,22179051 and 61604143)+2 种基金the National Key Research and Development Program of China(2021YFE0111000)the Special Fund of Taishan Scholar Program of Shandong Province(tsqnz20221141)the Foundation of Key Laboratory of Advanced Technique&Preparation for Renewable Energy Materials,Ministry of Education,Yunnan Normal University(OF2022-02)。
文摘A comprehensive understanding of the relevance between molecular structure and passivation ability to screen efficient modifiers is essential for enhancing the performance of perovskite solar cells(PSCs).Here,three similarπ-πstacking molecules namely benzophenone(BPN),diphenyl sulfone(DPS),and diphenyl sulfoxide(DPSO)are used as back-interface modifiers in carbon-based CsPbBr_(3)PSCs.After investigation,the results demonstrate the positive effect of the p-πconjugation characteristic inπ-πstacking molecules on maximizing their passivation ability.The p-πco njugation of DPSO enables a higher coordinative activity of oxygen atom in its S=O group than that in 0=S=O group of DPS and C=O group of BPN,which gives a superior passivation effect of DPSO on defects of perovskite films.The modification of DPSO also significantly improves the p-type behavior of perovskite films and the back-interfacial energetics matching,inducing an increase of hole extraction and a decrease of energy loss.Finally,the unencapsulated carbon-based CsPbBr_(3)PSCs with DPSO achieve a maximum power conversion efficiency of 10.60%and outstanding long-term stability in high-temperature,high-humidity(85℃,85%relative humidity)air environment.This work provides insights into the influence of the structure ofπ-πstacking molecules on their ability to improve the perovskite films quality and therefore the PSCs performance.
