This study investigates the morphology and oxidation behavior of thermally grown oxides(TGO) formed at the interface of NiCoCrAlYTa+7YSZ(7 wt% Y2O3-stabilized zirconia) coatings deposited by air plasma spray(APS...This study investigates the morphology and oxidation behavior of thermally grown oxides(TGO) formed at the interface of NiCoCrAlYTa+7YSZ(7 wt% Y2O3-stabilized zirconia) coatings deposited by air plasma spray(APS) in air environments at1050℃,1100℃,and 1150℃.The enrichment of Ta-rich oxides beneath the TGO,along with the segregation of Y and Ta at Al2O3 grain boundaries,effectively inhibited the outward diffusion of Al.During cyclic oxidation,the outward diffusion of Al is influenced by the content of Y and Ta elements.Dense fine-striped Al2O3 formed within the BC during the APS process,acting as a diffusion barrier to inhibit the outward diffusion of Al.The internal growth oxides generated during cyclic oxidation significantly reduced the coefficient of thermal expansion(CTE) of the bond coat(BC),thereby reducing the driving force for top coat(TC) spallation and extending the service life of thermal barrier coatings(TBCs).展开更多
针对空管系统危险源控制清单中关键信息识别与潜在隐患管理的问题,本文提出了一种基于威胁与差错管理(TEM,threat and error management)模型的空管安全信息相关性分析方法。首先,依据TEM模型的内在分类构建TEM模型本体;其次,利用信息...针对空管系统危险源控制清单中关键信息识别与潜在隐患管理的问题,本文提出了一种基于威胁与差错管理(TEM,threat and error management)模型的空管安全信息相关性分析方法。首先,依据TEM模型的内在分类构建TEM模型本体;其次,利用信息抽取技术从危险源控制清单文本中抽取结构化事件,利用深度自编码器网络模型和改进的余弦相似度公式进行文本语义相似度匹配;最后,基于贝叶斯网络对TEM模型本体类别的概率关系进行定量分析,得到威胁、差错和非期望的航空器状态之间的相关性。通过对民航空管系统危险源控制清单中数据的实例分析,识别并抽取出了文本中的关键信息、与空管运行安全强相关的实体词和事件类型,基于抽取结果对空管各运行环节安全性的提升提出合理建议。展开更多
Although magnesium holds great promise as a lightweight structural material,its oxidation failure mechanisms at elevated temperatures remain insufficiently understood.This study systematically investigates the oxidati...Although magnesium holds great promise as a lightweight structural material,its oxidation failure mechanisms at elevated temperatures remain insufficiently understood.This study systematically investigates the oxidation process of pure Mg at 500℃ through multi-scale characterization,with Mg-Gd-Y-Al alloy serving as a comparative system.The results reveal that during the initial oxidation stage(0–20 h),pure Mg exhibits oxidation kinetics similar to Mg-RE alloys,with SEM observations confirming the absence of visible cracks in its oxide layer,indicating its protective nature at this stage.However,during the accelerated oxidation period(20–300 h),the transformation from protective to non-protective behavior occurs due to the formation of microcrack networks and the rupture of oxidation blisters caused by Mg vapor,ultimately leading to catastrophic oxidation failure of pure Mg.In contrast,the Mg-RE alloy forms a dense,multi-layered oxide structure through the thermodynamic advantages of rare earth elements during oxidation,likely act as barriers to Mg outward diffusion and thereby enhancing oxidation resistance.This study provides new insights into the failure mechanisms of pure Mg and the protective role of rare earth elements in Mg alloys.展开更多
To further investigate the deformation twinning mechanism in wrought Ni-base superalloys under intermediatetemperature loading,we analyzed a turbine disk alloy by using aberration-corrected transmission electron micro...To further investigate the deformation twinning mechanism in wrought Ni-base superalloys under intermediatetemperature loading,we analyzed a turbine disk alloy by using aberration-corrected transmission electron microscopy(TEM).The twinning process occurs in two distinct stages:(1)stochastic nucleation of twin embryos occurs along{111}planes within isolated γ' phases;(2)extensive propagation across multiple γ' phases and γ channels,forming elongated,linear microtwins.Notably,Co enrichment at twin boundaries promotes twin formation by reducing the local stacking fault energy.After propagating through the γ/γ' phase boundary(PB),these boundaries can trap partial dislocations,arresting further twin growth and reducing the twin thickness.These findings provide key insights into the intermediate-temperature deformation twinning behavior of wrought Ni-base superalloys.展开更多
Two-dimensional(2D)transition-metal dichalcogenides(TMDCs)have quickly become key in the development of next-generation semiconductor technologies.Their van der Waals layered structures,atomic-scale thickness,and exce...Two-dimensional(2D)transition-metal dichalcogenides(TMDCs)have quickly become key in the development of next-generation semiconductor technologies.Their van der Waals layered structures,atomic-scale thickness,and excellent electronic properties offer a promising route to extend device scaling beyond the 1 nm node[1,2].Among the various synthesis strategies,chemical vapor deposition(CVD)using solid precursors has emerged as the most successful method for producing high-quality single-crystal TMDCs in laboratory settings[3−5].Despite substantial advancements in optimizing growth parameters and precursor chemistry,the fundamental mechanisms governing the early stages of nucleation,where atomic condensation and structural reorganization occur,remain elusive.These transient phenomena unfold across ultrafast timescales within complex reaction environments,posing significant challenges for experimental observation.展开更多
TEM and SHV are among the most prevalentβ-lactamases contributing toβ-lactam antibiotic resistance in clinical settings,leading to treatment challenges and increased mortality rates.Except for penicillin and early c...TEM and SHV are among the most prevalentβ-lactamases contributing toβ-lactam antibiotic resistance in clinical settings,leading to treatment challenges and increased mortality rates.Except for penicillin and early cephalosporins,TEM and SHV variants have evolved with the ability to hydrolyze the second-and third-generation cephalosporins,monobactams,and evenβ-lactamase inhibitors.Accurate detection of β-lactamases is of paramount importance for optimizing antibiotic use and combating antimicrobial resistance(AMR).While genetic detection methods,such as polymerase chain reaction(PCR),are widely employed,their positive results may lack phenotypic correlation due to the low or absent expression of blaSHV and blaTEM in many strains[1].Therefore,a direct protein-level detection method such as targeted proteomics is more precise and clinically relevant.This study highlights the development of a rapid detection method using targeted proteomics with high-resolution accurate mass(HRAM)Orbitrap MS for the direct detection of TEM and SHV in Enterobacteriaceae strains,which offers greater clinical relevance compared to conventional genetic approaches.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.52401093)Yunnan Major Scientific and Technological Projects(Grant No.202302AG050010)。
摘要This study investigates the morphology and oxidation behavior of thermally grown oxides(TGO) formed at the interface of NiCoCrAlYTa+7YSZ(7 wt% Y2O3-stabilized zirconia) coatings deposited by air plasma spray(APS) in air environments at1050℃,1100℃,and 1150℃.The enrichment of Ta-rich oxides beneath the TGO,along with the segregation of Y and Ta at Al2O3 grain boundaries,effectively inhibited the outward diffusion of Al.During cyclic oxidation,the outward diffusion of Al is influenced by the content of Y and Ta elements.Dense fine-striped Al2O3 formed within the BC during the APS process,acting as a diffusion barrier to inhibit the outward diffusion of Al.The internal growth oxides generated during cyclic oxidation significantly reduced the coefficient of thermal expansion(CTE) of the bond coat(BC),thereby reducing the driving force for top coat(TC) spallation and extending the service life of thermal barrier coatings(TBCs).
摘要针对空管系统危险源控制清单中关键信息识别与潜在隐患管理的问题,本文提出了一种基于威胁与差错管理(TEM,threat and error management)模型的空管安全信息相关性分析方法。首先,依据TEM模型的内在分类构建TEM模型本体;其次,利用信息抽取技术从危险源控制清单文本中抽取结构化事件,利用深度自编码器网络模型和改进的余弦相似度公式进行文本语义相似度匹配;最后,基于贝叶斯网络对TEM模型本体类别的概率关系进行定量分析,得到威胁、差错和非期望的航空器状态之间的相关性。通过对民航空管系统危险源控制清单中数据的实例分析,识别并抽取出了文本中的关键信息、与空管运行安全强相关的实体词和事件类型,基于抽取结果对空管各运行环节安全性的提升提出合理建议。
基金funded by the Natural Science Foundation of China(No.52471043,No.52127801)the Lingchuang Research Project(23GFC-JJ12–941)+1 种基金Scientific Research Program for Young Talents(24GFC-JJ12-131)of China National Nuclear CorporationExplorer Program of Shanghai(24TS1413800).
摘要Although magnesium holds great promise as a lightweight structural material,its oxidation failure mechanisms at elevated temperatures remain insufficiently understood.This study systematically investigates the oxidation process of pure Mg at 500℃ through multi-scale characterization,with Mg-Gd-Y-Al alloy serving as a comparative system.The results reveal that during the initial oxidation stage(0–20 h),pure Mg exhibits oxidation kinetics similar to Mg-RE alloys,with SEM observations confirming the absence of visible cracks in its oxide layer,indicating its protective nature at this stage.However,during the accelerated oxidation period(20–300 h),the transformation from protective to non-protective behavior occurs due to the formation of microcrack networks and the rupture of oxidation blisters caused by Mg vapor,ultimately leading to catastrophic oxidation failure of pure Mg.In contrast,the Mg-RE alloy forms a dense,multi-layered oxide structure through the thermodynamic advantages of rare earth elements during oxidation,likely act as barriers to Mg outward diffusion and thereby enhancing oxidation resistance.This study provides new insights into the failure mechanisms of pure Mg and the protective role of rare earth elements in Mg alloys.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDA0410000 and XDC014000O)the National Natural Science Foundation of China(Grant No.92477121)+2 种基金the National Key Research and Development Program of China(Grant No.2024YFA1208002)the Natural Science Foundation of Liaoning Province(Grant No.2024-MSBA-69)the Young Elite Scientist Sponsorship Program by CAST(Grant No.YESS20240545).
摘要To further investigate the deformation twinning mechanism in wrought Ni-base superalloys under intermediatetemperature loading,we analyzed a turbine disk alloy by using aberration-corrected transmission electron microscopy(TEM).The twinning process occurs in two distinct stages:(1)stochastic nucleation of twin embryos occurs along{111}planes within isolated γ' phases;(2)extensive propagation across multiple γ' phases and γ channels,forming elongated,linear microtwins.Notably,Co enrichment at twin boundaries promotes twin formation by reducing the local stacking fault energy.After propagating through the γ/γ' phase boundary(PB),these boundaries can trap partial dislocations,arresting further twin growth and reducing the twin thickness.These findings provide key insights into the intermediate-temperature deformation twinning behavior of wrought Ni-base superalloys.
摘要Two-dimensional(2D)transition-metal dichalcogenides(TMDCs)have quickly become key in the development of next-generation semiconductor technologies.Their van der Waals layered structures,atomic-scale thickness,and excellent electronic properties offer a promising route to extend device scaling beyond the 1 nm node[1,2].Among the various synthesis strategies,chemical vapor deposition(CVD)using solid precursors has emerged as the most successful method for producing high-quality single-crystal TMDCs in laboratory settings[3−5].Despite substantial advancements in optimizing growth parameters and precursor chemistry,the fundamental mechanisms governing the early stages of nucleation,where atomic condensation and structural reorganization occur,remain elusive.These transient phenomena unfold across ultrafast timescales within complex reaction environments,posing significant challenges for experimental observation.
基金supported by the National Natural Science Foundation of China(Grant Nos.:32141003,82330110,and 81803593)the CAMS Innovation Fund for Medical Sciences(CIFMS),China(Grant Nos.:2021-I2M-1-030,and 2021-I2M-1-039)+1 种基金the Fundamental Research Funds for the Central Universities,China(Grant No.:3332018094)the National Science and Technology Infrastructure of China(Project No.:National Pathogen Resource Center-NPRC-32).
摘要TEM and SHV are among the most prevalentβ-lactamases contributing toβ-lactam antibiotic resistance in clinical settings,leading to treatment challenges and increased mortality rates.Except for penicillin and early cephalosporins,TEM and SHV variants have evolved with the ability to hydrolyze the second-and third-generation cephalosporins,monobactams,and evenβ-lactamase inhibitors.Accurate detection of β-lactamases is of paramount importance for optimizing antibiotic use and combating antimicrobial resistance(AMR).While genetic detection methods,such as polymerase chain reaction(PCR),are widely employed,their positive results may lack phenotypic correlation due to the low or absent expression of blaSHV and blaTEM in many strains[1].Therefore,a direct protein-level detection method such as targeted proteomics is more precise and clinically relevant.This study highlights the development of a rapid detection method using targeted proteomics with high-resolution accurate mass(HRAM)Orbitrap MS for the direct detection of TEM and SHV in Enterobacteriaceae strains,which offers greater clinical relevance compared to conventional genetic approaches.