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Friction 2024年第10期12卷 2389-2398页

作者： Fei LIANG Yixing SUN Hongyuan WAN Yong LI Wenhao LU ao meng Lei GU Zhaoping LUO Yan LIN Yaping ZHANG Xiang CHEN Nano and Heterogeneous Materials Center School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China Key Laboratory of Power Beam Processing AVIC Manufacturing Technology InstituteBeijing 100024China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

The pronounced brittleness of hard Laves phase intermetallics is detrimental to their tribological properties at room *** this study,we utilized a heterogeneous structure to engineer an ultrastrong dual-phase(Laves+B2)AlCoFeNiNb high-entropy alloy that exhibits a low wear rate(3.82×10-6 mm3/(N·m))at room *** wear resistance in the ball-on-disc sliding friction test with the counterpart of Al2O3 balls stems from the activated deformation ability in the ultrafine Laves lamellae under heterogeneous interface ***,as tribological stress intensifies,the surface deformation mechanism transitions from dislocation slip on the basal and pyramidal planes to a unique combination of local shear and grain rotation within the Laves *** study illuminates fresh perspectives for mitigating the embrittling effect of Laves phase intermetallics under tribological loading and for the development of wear-resistant materials.

关键词： wear resistance high-entropy alloy Laves phase heterogeneous structure

颈动脉粥样硬化斑块三维超声参数评估2型糖尿病患者冠心病风险

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中国医学影像技术 2024年第9期40卷 1332-1335页

作者：韩莹敖梦王志刚重庆医科大学附属第二医院超声科重庆400010 超声分子影像重庆市重点实验室重庆400010

目的观察颈动脉粥样硬化斑块三维(3D)超声容积参数预测2型糖尿病(T2DM)患者冠心病风险的价值。方法前瞻性纳入88例T2DM合并颈动脉粥样硬化斑块患者,根据冠状动脉造影结果将其分为冠心病组(n=56)及非冠心病组(n=32)。记录临床资料、颈动... 详细信息

目的观察颈动脉粥样硬化斑块三维(3D)超声容积参数预测2型糖尿病(T2DM)患者冠心病风险的价值。方法前瞻性纳入88例T2DM合并颈动脉粥样硬化斑块患者,根据冠状动脉造影结果将其分为冠心病组(n=56)及非冠心病组(n=32)。记录临床资料、颈动脉粥样硬化斑块二维(2D)及3D超声容积结果,比较组间基本资料及超声参数,以多因素logistic回归分析筛选T2DM患者发生冠心病的独立预测因素,绘制受试者工作特征曲线,以曲线下面积(AUC)比较颈动脉粥样硬化斑块超声参数预测T2DM患者发生冠心病风险的效能。结果相比非冠心病组,冠心病组T2DM病程、糖化血红蛋白及低密度脂蛋白(LDL)水平均较高,颈动脉粥样硬化斑块体积较大而灰度中位数(GSM)较低(P均<0.05)。颈动脉粥样硬化斑块体积、GSM、T2DM病程及LDL水平为T2DM患者发生冠心病的预测因素(P均<0.05);斑块体积、GSM及二者联合的AUC分别为0.864、0.828及0.927,且二者联合预测效能高于单一因素(P均<0.05)。结论以3D超声容积成像获取的颈动脉粥样硬化斑块体积及GSM均可间接反映T2DM患者罹患冠心病风险;二者联合预测冠心病风险的效能更高。

关键词：糖尿病,2型糖尿病并发症冠心病颈动脉狭窄超声检查前瞻性研究

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基于升降轨SAR数据的连续箱梁桥精细变形

东北大学学报（自然科学版） 2024年第3期45卷 391-400页

作者：魏恋欢王啸天敖萌李鑫东北大学资源与土木工程学院辽宁沈阳110819

针对桥梁精细变形监测问题,提出一种考虑由温度引起的桥梁变形(简称温度变形)的升降轨合成孔径雷达(synthetic aperture radar,SAR)数据融合方法.首先,以连续箱梁桥为研究对象,分别使用升降轨SAR数据集,基于小基线子集干涉测量法(small ... 详细信息

针对桥梁精细变形监测问题,提出一种考虑由温度引起的桥梁变形(简称温度变形)的升降轨合成孔径雷达(synthetic aperture radar,SAR)数据融合方法.首先,以连续箱梁桥为研究对象,分别使用升降轨SAR数据集,基于小基线子集干涉测量法(small baseline subsets interferometric SAR,SBAS-InSAR)提取视线向(line-of-sight,LOS)变形;然后,利用最小二乘法构建温度变形模型,分离周期性温度变形与长期性趋势变形;最后,结合桥梁结构特征,基于时空插值和奇异值分解方法实现升降轨数据融合,提取温度变形、纵桥向(即桥梁延伸方向)及垂直向趋势变形,分析桥梁变形机制及变形成因.结果表明,该方法可提取精确的桥梁温度变形及三维变形,为桥梁健康监测提供可靠的方法支撑.

关键词：小基线子集连续箱梁桥温度变形建模数据融合三维变形

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基于DS-InSAR的蒲河煤矿采空区地表形变监测与开采参数反演

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东北大学学报（自然科学版） 2024年第6期45卷 866-873,882页

作者：敖萌孙颖魏恋欢张化南东北大学资源与土木工程学院辽宁沈阳110819 辽宁省地质矿产调查院有限责任公司辽宁沈阳110031

合成孔径雷达干涉测量(InSAR)技术在有植被覆盖的矿区难以识别到足够多的监测点目标,导致形变结果无法反映矿区真实形变特征.采用分布式散射体InSAR分析方法,能够有效提高植被密集区域雷达相干目标数量,从而准确描述矿区形变的时间演化... 详细信息

合成孔径雷达干涉测量(InSAR)技术在有植被覆盖的矿区难以识别到足够多的监测点目标,导致形变结果无法反映矿区真实形变特征.采用分布式散射体InSAR分析方法,能够有效提高植被密集区域雷达相干目标数量,从而准确描述矿区形变的时间演化规律和空间分布特征.矿区长期高强度开采会引发采空区的地表变形,严重威胁矿区基础设施建设和人员生命财产安全.基于沈阳蒲河煤矿采空区InSAR高精度监测数据,通过地球物理建模反演得到矿区地下关键开采参数,模拟的矿区形变场与InSAR监测结果较为一致,且反演开采参数符合真实开采情况.结合InSAR监测结果与Okada模型反演矿区参数,能够准确描述由采矿造成的采空区地表形变,为科学制定地下开采计划及矿区可持续开发提供重要信息.

关键词：矿区地面沉降合成孔径雷达干涉测量分布式散射体地球物理建模形变监测

基于增强现实和稳态视觉诱发电位的视觉目标检测系统

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生物医学工程学杂志 2024年第4期41卷 684-691页

作者：郭孟澳杨帮华耿亦婷竭荣昕张永怀郑炎炎上海大学机电工程与自动化学院上海200444 上海韶脑传感技术有限公司上海201900 浙江省温州人民医院浙江温州325041

本研究探讨了一种基于增强现实(AR)环境和稳态视觉诱发电位(SSVEP)的脑机接口(BCI)系统,用于在真实场景下通过视觉注视完成对现实物品的选取任务。该系统结合了目标检测技术和AR技术,在真实物体上附加视觉增强效果,从而给予用户视觉刺... 详细信息

本研究探讨了一种基于增强现实(AR)环境和稳态视觉诱发电位(SSVEP)的脑机接口(BCI)系统,用于在真实场景下通过视觉注视完成对现实物品的选取任务。该系统结合了目标检测技术和AR技术,在真实物体上附加视觉增强效果,从而给予用户视觉刺激诱发相关脑电信号,再利用SSVEP技术解析脑电信号,完成对用户关注物体的识别。此外,本文采用了基于自适应动态时间窗的滤波器组典型相关分析算法实现对受试者脑电信号的快速解析。实验结果表明,该系统可以有效地识别解析SSVEP信号,对用户视觉目标的识别平均准确率达到了90.6%。该系统拓展了SSVEP信号在现实生活场景中的应用,在帮助行动不便和肢体功能受损患者进行物品选取任务上具备可行性和有效性。

关键词：脑机接口稳态视觉诱发电位增强现实目标识别

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Dislocation me diate d dynamic tension-compression asymmetry of a Ni_(2)CoFeV_(0.5)Mo_(0.2) medium entropy alloy

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Journal of Materials Science & Technology 2023年第28期159卷 204-218页

作者： ao meng Xiang Chen Yazhou Guo Yiping Lu Yonghao Zhao Nano and Heterogeneous Materials Center School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province) School of Materials Science and EngineeringDalian University of TechnologyDalian 116024China

Although tension-compression(T-C)asymmetry in yield strength was rarely documented in coarse-grained face centered cubic(FCC)metals as critical resolved shear stress(CRSS)for dislocation slip differs little between tension and compression,the T-C asymmetry in strength,i.e.,higher strength when loaded in compression than in tension,was reported in some FCC high entropy alloys(HEAs)due to twinning and phase transitions activated at high strain regimes in *** this paper,we demonstrate a reversed and atypical tension-compression asymmetry(tensile strength markedly exceeds compressive strength)in a non-equiatomic FCC Ni_(2)CoFeV_(0.5)Mo_(0.2) medium entropy alloy(MEA)under dynamic loading,wherein dislocation slip governs dynamic deformation without twins or phase *** asymme-try can be primarily interpreted as higher CRSS and more hard slip modes(lower average Schmid factor)activated in grains under dynamic tension than ***,larger strain rate sensitivity in dy-namic tension overwhelmingly contributes to the higher flow stress,thanks to the occurrence of more immobile Lomer-locks,narrower spacing of planar slip bands and higher dislocation *** finding may provide some insights into designing MEAs/HEAs with desired properties under extreme conditions such as blast,impact and crash.

关键词： Medium entropy alloy Dynamic deformation Tension-compression asymmetry Slip trace analysis EBSD and TEM

Exosome-functionalized magnesium-organic framework-based scaffoldswith osteogenic, angiogenic and anti-inflammatory properties foraccelerated bone regeneration

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Bioactive Materials 2022年第12期7卷 26-41页

作者： Yue Kang Chang Xu Ling’ao meng Xufeng Dong Min Qi Daqing Jiang Department of Breast Surgery Cancer Hospital of China Medical University44 Xiaoheyan RoadDadong DistrictShenyang110042PR China School of Materials Science and Engineering Dalian University of Technology2 Linggong RoadGanjingzi DistrictDalian116024China

Exosomes derived from human adipose-derived stem cells (hADSCs-Exos) have shown potential as an effectivetherapeutic tool for repairing bone defects. Although metal-organic framework (MOF) scaffolds are promisingstrategies for bone tissue regeneration, their potential use for exosome loading remains unexplored. In this study,motivated by the potential advantages of hADSCs-Exos and Mg-GA MOF, we designed and synthesized anexosome-functionalized cell-free PLGA/Mg-GA MOF (PLGA/Exo-Mg-GA MOF) scaffold, taking using of thebenefits of hADSCs-Exos, Mg2+, and gallic acid (GA) to construct unique nanostructural interfaces to enhanceosteogenic, angiogenic and anti-inflammatory capabilities simultaneously. Our in vitro work demonstrated thebeneficial effects of PLGA/Exo-Mg-GA MOF composite scaffolds on the osteogenic effects in human bonemarrow-derived mesenchymal stem cells (hBMSCs) and angiogenic effects in human umbilical endothelial cells(HUVECs). Slowly released hADSCs-Exos from composite scaffolds were phagocytosed by co-cultured cells,stabilized the bone graft environment, ensured blood supply, promoted osteogenic differentiation, and acceleratedbone reconstruction. Furthermore, our in vivo experiments with rat calvarial defect model showed thatPLGA/Exo-Mg-GA MOF scaffolds promoted new bone formation and satisfactory osseointegration. Overall, weprovide valuable new insights for designing exosome-coated nanocomposite scaffolds with enhanced osteogenesisproperty.

关键词： Metal-organic framework Exosomes Magnesium ions Gallic acid Osteogenesis Angiogenesis Anti-inflammation Rat calvarial defect model Bone regeneration

Analysis of sensitivity to hydrate blockage risk in natural gas gathering pipeline

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Petroleum Science 2024年第4期21卷 2723-2733页

作者： ao-Yang Zhang meng Cai Na Wei Hai-Tao Li Chao Zhang Jun Pei Xin-Wei Wang State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Research Institute of Production Engineering Daqing Oilfield Co.Ltd.

During the operational process of natural gas gathering and transmission pipelines, the formation of hydrates is highly probable, leading to uncontrolled movement and aggregation of hydrates. The continuous migration and accumulation of hydrates further contribute to the obstruction of natural gas pipelines, resulting in production reduction, shutdowns, and pressure build-ups. Consequently, a cascade of risks is prone to occur. To address this issue, this study focuses on the operational process of natural gas gathering and transmission pipelines, where a comprehensive framework is established. This framework includes theoretical models for pipeline temperature distribution, pipeline pressure distribution, multiphase flow within the pipeline, hydrate blockage, and numerical solution methods. By analyzing the influence of inlet temperature, inlet pressure, and terminal pressure on hydrate formation within the pipeline, the sensitivity patterns of hydrate blockage risks are derived. The research indicates that reducing inlet pressure and terminal pressure could lead to a decreased maximum hydrate formation rate, potentially mitigating pipeline blockage during natural gas transportation. Furthermore, an increase in inlet temperature and terminal pressure, and a decrease in inlet pressure, results in a displacement of the most probable location for hydrate blockage towards the terminal station. However,it is crucial to note that operating under low-pressure conditions significantly elevates energy consumption within the gathering system, contradicting the operational goal of energy efficiency and reduction of energy consumption. Consequently, for high-pressure gathering pipelines, measures such as raising the inlet temperature or employing inhibitors, electrical heat tracing, and thermal insulation should be adopted to prevent hydrate formation during natural gas transportation. Moreover, considering abnormal conditions such as gas well production and pipeline network s

关键词： Natural gas hydrates Gathering pipeline Temperature variation Hydrate formation rate Sensitivity analysis

光梭成像及梯度自旋回波技术在MRCP应用中的优势

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中华肝脏外科手术学电子杂志 2024年第2期13卷 182-188页

作者：熊安妮黄锦彬汪昕荣雷漫诗邓锶锶向青孟占鳌中山大学附属第三医院放射科广州510630

目的:探讨光梭成像(Ucs)及梯度自旋回波(GRASE)技术在MRCP应用中的价值。方法:本研究对象为2022年11月至2022年12月在中山大学附属第三医院行MRCP检查的30例患者。其中男15例,女15例;平均年龄(52±17)岁。患者均签署知情同意书,符合医... 详细信息

目的:探讨光梭成像(Ucs)及梯度自旋回波(GRASE)技术在MRCP应用中的价值。方法:本研究对象为2022年11月至2022年12月在中山大学附属第三医院行MRCP检查的30例患者。其中男15例,女15例;平均年龄(52±17)岁。患者均签署知情同意书,符合医学伦理学规定。所有患者分别采用3种不同方案扫描:常规方案采用3D快速自旋回波技术结合并行采集、呼吸触发技术(RT);Ucs方案采用3D-Ucs技术结合RT的MRCP;快速GRASE方案采用3D快速自旋回波序列结合GRASE和屏气技术。客观评价:胆总管的信噪比(SNR)、对比度(CR)以及对比噪声比(CNR)。主观评价:两名10年以上腹部MRI诊断经验的放射科医师采用盲法5分标准对胆胰管的导管可见性、运动伪影、背景抑制、图像清晰度、整体图像质量进行单独评分,最后取5个指标的平均分。同时记录数据采集时间。结果:客观评价显示,Ucs方案组SNR中位数为13(9,18),明显高于常规方案组的8(5,11) (Z=3.73,P0.8,P<0.05)。对于呼吸均匀患者,Ucs方案组数据采集时间较常规方案组缩短19%。对于呼吸紊乱患者,GRASE方案组数据采集时间较常规方案组缩短近92%,较Ucs方案组缩短近90%。结论:与常规扫描方案相比,对于呼吸均匀患者Ucs方案组图像质量和数据采集时间明显占优势;而对于呼吸紊乱患者,快速GRASE方案占优势。Ucs方案为主快速GRASE方案辅助的MRCP序列组合相比常规方案更加优化。

关键词：磁共振胰胆管成像光梭成像压缩感知梯度自旋回波并行采集呼吸触发屏气

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C@Ag core‒shell structure as lubricating additives towards high efficient lubrication

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Friction 2024年第9期12卷 1991-2003页

作者： Dong ao Xiaoqiang FAN Minhao ZHU Key Laboratory of Advanced Technologies of Materials(Ministry of Education) School of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China Tribology Research Institute School of Mechanical EngineeringSouthwest Jiaotong UniversityChengdu 610031China

Efficient cooperative lubrication can be achieved via the introduction of core‒shell structure lubricant additives with hard core and soft shell,for obtaining the expected anti-wear performance from the structural changes in the friction *** this study,C@Ag microspheres with a core‒shell structure were prepared by the redox method with carbon spheres as the core and Ag nanoparticles as the *** tribological behaviors as base oil(G1830)additive with different concentrations were investigated in *** with base oil,the addition of C@Ag particles at 0.5 wt%can reduce the coefficient of friction(COF)and wear volume(Wv)up to 15.5%and 88%,*** importantly,C@Ag particles provide superior lubrication performance to single additive(like carbon sphere(CS)and Ag nanoparticle).C@Ag core‒shell particles contribute to the formation of tribo-film by melt bonding of flexible Ag and carbon sphere(CS)toward excellent self-repair performance and high-efficiency ***,core‒shell structural nanoparticles with hard-core and soft-shell hold bright future for high-performance lubrication application.

关键词： C@Ag microspheres tribo-film self-repair performance high-efficiency lubrication