飞行时间二次离子质谱(time-of-flight secondary ion mass spectrometry,TOF-SIMS)作为一种高灵敏度、高分辨率的表面分析技术,在材料科学领域应用广泛。聚焦于TOF-SIMS在钢铁材料分析中的应用,探讨了其在薄膜/钝化膜分析、微量元素残...飞行时间二次离子质谱(time-of-flight secondary ion mass spectrometry,TOF-SIMS)作为一种高灵敏度、高分辨率的表面分析技术,在材料科学领域应用广泛。聚焦于TOF-SIMS在钢铁材料分析中的应用,探讨了其在薄膜/钝化膜分析、微量元素残留、晶界富集、表面基团表征及氢元素分析等方面的潜力。凭借高空间分辨率和卓越的化学灵敏度,TOF-SIMS能提供高精度的表面成分分布、深度剖析与三维成像结果,有效克服了能量色散X射线光谱(EDS)等传统分析方法在灵敏度与元素检测范围上的局限性。通过镀锡板黄斑缺陷、ZM镀层钢板残油及BW600钢晶界元素富集等案例,展示了该技术的实际应用。特别是在氢脆研究中,TOF-SIMS能够高效、精确地表征氢在材料中的分布,为揭示氢脆机理提供了独特优势。综上,TOF-SIMS技术在钢铁材料缺陷分析中具有广阔的应用前景,可为钢铁行业提供精准的分析手段,从而推动相关领域的技术进步。展开更多
Flight feathers represent a hallmark innovation of avian evolution.Recent comparative genomic analyses identified a 284 bp avian-specific highly conserved element(ASHCE)located within the eighth intron of the SIM bHLH...Flight feathers represent a hallmark innovation of avian evolution.Recent comparative genomic analyses identified a 284 bp avian-specific highly conserved element(ASHCE)located within the eighth intron of the SIM bHLH transcription factor 1(Sim1)gene,postulated to act as a cis-regulatory element governing flight feather morphogenesis.To investigate its functional significance,genome-edited(GE)primordial germ cell(PGC)lines carrying targeted ASHCE deletions were generated using CRISPR/Cas9-mediated editing,with germline chimeric males subsequently mated with wild-type(WT)hens to obtain GE progeny.The resulting GE chickens harbored 257-260 bp deletions,excising approximately half of the Sim1-ASHCE sequence.Reverse transcription-quantitative real-time polymerase chain reaction(RT-qPCR)analysis showed an average 0.32-fold reduction in Sim1 expression in the forelimbs of GE embryos at day 8(E8)compared to WT counterparts.Despite this,GE chickens developed structurally normal flight and tail feathers.In situ hybridization localized Sim1 expression to the posterior mesenchyme surrounding flight feather buds in E8 WT embryos,but not within the buds themselves.These results suggest that partial deletion of Sim1-ASHCE,despite diminishing Sim1 expression,does not disrupt flight feather formation.The excised region appears to possess enhancer activity toward Sim1 but is dispensable for flight feather development.Complete ablation of the ASHCE will be necessary to fully resolve the regulatory role of Sim1 in avian feather morphogenesis.展开更多
针对联合作战信息交换需求和多军兵种作战数据互联互通问题,采用指挥控制系统与仿真系统之间交互性标准(command and control systems-simulation systems interoperation,C2SIM)标准指导实现指挥控制系统、仿真系统和无人系统之间的高...针对联合作战信息交换需求和多军兵种作战数据互联互通问题,采用指挥控制系统与仿真系统之间交互性标准(command and control systems-simulation systems interoperation,C2SIM)标准指导实现指挥控制系统、仿真系统和无人系统之间的高效互操作。概述C2SIM的地位、作用和开发概况;介绍C2SIM逻辑数据模型开发方法;从C2SIM核心本体、领域本体扩展、本体到XML Schema的转换和参考实现等方面,分析C2SIM的关键技术问题;探讨C2SIM标准在北约近年中实兵演习中的应用情况;总结C2SIM的发展和影响,为我军标准化互操作技术的构建提供方法和技术上的启发和借鉴。结果表明,该研究可有效提高军事信息系统的开发能力和质量。展开更多
Although train modeling research is vast, most available simulation tools are confined to city-or trip-scale analysis, primarily offering micro-level simulations of network segments. This paper addresses this void by ...Although train modeling research is vast, most available simulation tools are confined to city-or trip-scale analysis, primarily offering micro-level simulations of network segments. This paper addresses this void by developing the Ne Train Sim simulator for heavy long-haul freight trains on a network of multiple intersecting tracks. The main objective of this simulator is to enable a comprehensive analysis of energy consumption and the associated carbon footprint for the entire train system. Four case studies were conducted to demonstrate the simulator's performance. The first case study validates the model by comparing Ne Train Sim output to empirical trajectory data. The results demonstrate that the simulated trajectory is precise enough to estimate the train energy consumption and carbon dioxide emissions. The second application demonstrates the train-following model considering six trains following each other. The results showcase the model ability to maintain safefollowing distances between successive trains. The next study highlights the simulator's ability to resolve train conflicts for different scenarios. Finally, the suitability of the Ne Train Sim for modeling realistic railroad networks is verified through the modeling of the entire US network and comparing alternative powertrains on the fleet energy consumption.展开更多
Aiming at the problem of low surface defect detection accuracy of industrial products, an object detection method based on simplified spatial pyramid pooling fast(Sim SPPF) hybrid pooling improved you only look once v...Aiming at the problem of low surface defect detection accuracy of industrial products, an object detection method based on simplified spatial pyramid pooling fast(Sim SPPF) hybrid pooling improved you only look once version 5s(YOLOV5s) model is proposed. The algorithm introduces channel attention(CA) module, simplified SPPF feature vector pyramid and efficient intersection over union(EIOU) loss function. Feature vector pyramids fuse high-dimensional and low-dimensional features, which makes semantic information richer. The CA mechanism performs maximum pooling and average pooling operations on the feature map. Hybrid pooling comprehensively improves detection computing efficiency and accurate deployment ability. The results show that the improved YOLOV5s model is better than the original YOLOV5s model. The average test accuracy(mAP) can reach 91.8%, which can be increased by 17.4%, and the detection speed can reach 108 FPS, which can be increased by 18 FPS. The improved model is practicable, and the overall performance is better than other conventional models.展开更多
为了探究山苍子精油中主要成分的绝对含量,建立了一种气相色谱-质谱/选择离子扫描(gas chromatography mass spectrometry/selective ion monitoring,GC-MS/SIM)方法,对其中主要成分(α-蒎烯、β-蒎烯、D-柠檬烯、1,8-桉叶素、芳樟醇、...为了探究山苍子精油中主要成分的绝对含量,建立了一种气相色谱-质谱/选择离子扫描(gas chromatography mass spectrometry/selective ion monitoring,GC-MS/SIM)方法,对其中主要成分(α-蒎烯、β-蒎烯、D-柠檬烯、1,8-桉叶素、芳樟醇、香茅醛、柠檬醛)进行了定性和定量分析。该方法简便、高效,在25 min内山苍子精油中各成分分离良好。各成分在一定范围内均线性关系良好(R2>0.999),精密度、稳定性及重复性均符合要求,平均加标回收率为93.40%~107.35%。结果表明:该方法符合方法学验证要求,可用于山苍子精油的多成分含量测定,并为其质量评价提供依据。展开更多
This paper introduces a pioneering application of secondary ion mass spectrometry(SIMS)for estimating the electronic properties of Pb_(1-x)Sn_(x)Te,a compound categorized as a topological crystalline insulator.The pro...This paper introduces a pioneering application of secondary ion mass spectrometry(SIMS)for estimating the electronic properties of Pb_(1-x)Sn_(x)Te,a compound categorized as a topological crystalline insulator.The proposed approach marks the first application of SIMS for such estimations and focuses on investigating variations in ionization probabilities and shifts in the energy distribution of secondary ions.The ionization probabilities are influenced by pivotal parameters such as the material's work function and electron affinity.The derivation of these parameters hinges upon the energy gap's positioning relative to the vacuum level for varying values of within the Pb_(1-x)Sn_(x)Te compound.The findings elucidate noteworthy alterations in SIMS signals,particularly near the critical point of band-gap closing.展开更多
文摘飞行时间二次离子质谱(time-of-flight secondary ion mass spectrometry,TOF-SIMS)作为一种高灵敏度、高分辨率的表面分析技术,在材料科学领域应用广泛。聚焦于TOF-SIMS在钢铁材料分析中的应用,探讨了其在薄膜/钝化膜分析、微量元素残留、晶界富集、表面基团表征及氢元素分析等方面的潜力。凭借高空间分辨率和卓越的化学灵敏度,TOF-SIMS能提供高精度的表面成分分布、深度剖析与三维成像结果,有效克服了能量色散X射线光谱(EDS)等传统分析方法在灵敏度与元素检测范围上的局限性。通过镀锡板黄斑缺陷、ZM镀层钢板残油及BW600钢晶界元素富集等案例,展示了该技术的实际应用。特别是在氢脆研究中,TOF-SIMS能够高效、精确地表征氢在材料中的分布,为揭示氢脆机理提供了独特优势。综上,TOF-SIMS技术在钢铁材料缺陷分析中具有广阔的应用前景,可为钢铁行业提供精准的分析手段,从而推动相关领域的技术进步。
基金supported by the Ministry of Agriculture and Rural Affairs of the People's Republic of China(125A0607)Department of Science and Technology of Yunnan Province(XDYC-KJLJ-2022-0004)。
文摘Flight feathers represent a hallmark innovation of avian evolution.Recent comparative genomic analyses identified a 284 bp avian-specific highly conserved element(ASHCE)located within the eighth intron of the SIM bHLH transcription factor 1(Sim1)gene,postulated to act as a cis-regulatory element governing flight feather morphogenesis.To investigate its functional significance,genome-edited(GE)primordial germ cell(PGC)lines carrying targeted ASHCE deletions were generated using CRISPR/Cas9-mediated editing,with germline chimeric males subsequently mated with wild-type(WT)hens to obtain GE progeny.The resulting GE chickens harbored 257-260 bp deletions,excising approximately half of the Sim1-ASHCE sequence.Reverse transcription-quantitative real-time polymerase chain reaction(RT-qPCR)analysis showed an average 0.32-fold reduction in Sim1 expression in the forelimbs of GE embryos at day 8(E8)compared to WT counterparts.Despite this,GE chickens developed structurally normal flight and tail feathers.In situ hybridization localized Sim1 expression to the posterior mesenchyme surrounding flight feather buds in E8 WT embryos,but not within the buds themselves.These results suggest that partial deletion of Sim1-ASHCE,despite diminishing Sim1 expression,does not disrupt flight feather formation.The excised region appears to possess enhancer activity toward Sim1 but is dispensable for flight feather development.Complete ablation of the ASHCE will be necessary to fully resolve the regulatory role of Sim1 in avian feather morphogenesis.
文摘针对联合作战信息交换需求和多军兵种作战数据互联互通问题,采用指挥控制系统与仿真系统之间交互性标准(command and control systems-simulation systems interoperation,C2SIM)标准指导实现指挥控制系统、仿真系统和无人系统之间的高效互操作。概述C2SIM的地位、作用和开发概况;介绍C2SIM逻辑数据模型开发方法;从C2SIM核心本体、领域本体扩展、本体到XML Schema的转换和参考实现等方面,分析C2SIM的关键技术问题;探讨C2SIM标准在北约近年中实兵演习中的应用情况;总结C2SIM的发展和影响,为我军标准化互操作技术的构建提供方法和技术上的启发和借鉴。结果表明,该研究可有效提高军事信息系统的开发能力和质量。
基金funded in part by the Advanced Research Projects AgencyEnergy (ARPA-E), U.S. Department of Energy, under award number DE-AR0001471。
文摘Although train modeling research is vast, most available simulation tools are confined to city-or trip-scale analysis, primarily offering micro-level simulations of network segments. This paper addresses this void by developing the Ne Train Sim simulator for heavy long-haul freight trains on a network of multiple intersecting tracks. The main objective of this simulator is to enable a comprehensive analysis of energy consumption and the associated carbon footprint for the entire train system. Four case studies were conducted to demonstrate the simulator's performance. The first case study validates the model by comparing Ne Train Sim output to empirical trajectory data. The results demonstrate that the simulated trajectory is precise enough to estimate the train energy consumption and carbon dioxide emissions. The second application demonstrates the train-following model considering six trains following each other. The results showcase the model ability to maintain safefollowing distances between successive trains. The next study highlights the simulator's ability to resolve train conflicts for different scenarios. Finally, the suitability of the Ne Train Sim for modeling realistic railroad networks is verified through the modeling of the entire US network and comparing alternative powertrains on the fleet energy consumption.
基金supported by the Tianjin Postgraduate Research Innovation Project (No.2022SKY286)the National Science and the National Key Research and Development Program (No.2022YFF0706000)。
文摘Aiming at the problem of low surface defect detection accuracy of industrial products, an object detection method based on simplified spatial pyramid pooling fast(Sim SPPF) hybrid pooling improved you only look once version 5s(YOLOV5s) model is proposed. The algorithm introduces channel attention(CA) module, simplified SPPF feature vector pyramid and efficient intersection over union(EIOU) loss function. Feature vector pyramids fuse high-dimensional and low-dimensional features, which makes semantic information richer. The CA mechanism performs maximum pooling and average pooling operations on the feature map. Hybrid pooling comprehensively improves detection computing efficiency and accurate deployment ability. The results show that the improved YOLOV5s model is better than the original YOLOV5s model. The average test accuracy(mAP) can reach 91.8%, which can be increased by 17.4%, and the detection speed can reach 108 FPS, which can be increased by 18 FPS. The improved model is practicable, and the overall performance is better than other conventional models.
文摘为了探究山苍子精油中主要成分的绝对含量,建立了一种气相色谱-质谱/选择离子扫描(gas chromatography mass spectrometry/selective ion monitoring,GC-MS/SIM)方法,对其中主要成分(α-蒎烯、β-蒎烯、D-柠檬烯、1,8-桉叶素、芳樟醇、香茅醛、柠檬醛)进行了定性和定量分析。该方法简便、高效,在25 min内山苍子精油中各成分分离良好。各成分在一定范围内均线性关系良好(R2>0.999),精密度、稳定性及重复性均符合要求,平均加标回收率为93.40%~107.35%。结果表明:该方法符合方法学验证要求,可用于山苍子精油的多成分含量测定,并为其质量评价提供依据。
文摘This paper introduces a pioneering application of secondary ion mass spectrometry(SIMS)for estimating the electronic properties of Pb_(1-x)Sn_(x)Te,a compound categorized as a topological crystalline insulator.The proposed approach marks the first application of SIMS for such estimations and focuses on investigating variations in ionization probabilities and shifts in the energy distribution of secondary ions.The ionization probabilities are influenced by pivotal parameters such as the material's work function and electron affinity.The derivation of these parameters hinges upon the energy gap's positioning relative to the vacuum level for varying values of within the Pb_(1-x)Sn_(x)Te compound.The findings elucidate noteworthy alterations in SIMS signals,particularly near the critical point of band-gap closing.
