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Selective laser melting of dense and crack-free AlCoCrFeNi_(2.1) eutectic high entropy alloy: Synergizing strength and ductility

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Journal of Materials Science & Technology 2022年第22期117卷 133-145页

作者： Lin He Shiwei Wu Anping Dong haibin tang Dafan Du Guoliang Zhu Baode Sun Wentao Yan Shanghai Key Lab of Advanced High-temperature Materials and Precision Forming and State Key Lab of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Mechanical Engineering National University of Singapore117575Singapore School of Intelligent Manufacturing Nanjing University of Science and TechnologyNanjing 210094China

Additively manufactured high-entropy alloys generally suffer from low strength and/or poor ductility.In this work,by leveraging the good castability of eutectic high entropy alloys and high cooling rate of selective laser melting(SLM),we report a nearly fully dense and crack-free as-SLM AlCoCrFeNi_(2.1) eutectic high entropy alloy with an exceptional strength-ductility synergy,showing an ultrahigh yield strength of 982.1±35.2 MPa and an ultimate tensile strength of 1322.8±54.9 MPa together with an elongation to fracture of 12.3±0.5%.Such strength-ductility enhancement is owing to the heterogeneous eutectic microstructure consisting of the columnar,equiaxed,and“L-shape”cells with much refined sizes down to nanoscales.The morphology of cells in the transition zone is related to the misorientation between the growth direction of adjacent layers.This heterogeneous eutectic microstructure is the result of the graingrowth behavior dominated by the mechanisms of the epitaxial growth and growth of heterogeneous nuclei in SLM.Our current results provide a new methodology for the future design of ultrahigh-strength and ductile SLM-fabricated metallic materials including HEAs,and other printable alloys for various structural applications.

关键词： Additive manufacturing High entropy alloy Microstructure Mechanical properties Laser Crack-free

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The azimuthal currents in the ion-driven magnetic nozzle

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Propulsion and Power Research 2022年第4期11卷 457-472页

作者： Zhiyuan Chen Yibai Wang haibin tang Junxue Ren Min Li Peng Wu Jinbin Cao School of Astronautics Beihang UniversityBeijing102206China Key Laboratory of Spacecraft Design Optimization and Dynamic Simulation Technologies Ministry of EducationBeijing102206China Laboratory of Space Environment Monitoring and Information Processing Ministry of Industry and Information TechnologyBeijing102206China Innovation Academy of Microsatellites Chinese Academy of SciencesShanghai201203China School of Space and Environment Beihang UniversityBeijing102206China

Ion-driven magnetic nozzles(Ti>Te)are designed as intrinsic parts of cutting-edge propulsive technologies such as variable specific impulse magnetoplasma rockets(VASIMRs)and applied-field magnetoplasmadynamic thrusters.Employing a two-dimensional axisymmetric particle-in-cell(PIC)code,in the ion-driven magnetic nozzle,the compositions and distributions of azimuthal currents in different axial regions are investigated under various inlet ion temperatures Ti0 and found to differ dramatically from that in the electron-driven magnetic nozzles.Previously reported to be all paramagnetic and vanishing under a high magnetic field,the azimuthal currents resulting from the E 3 B drift are shown to turn diamagnetic and sustain a considerable magnitude when Ti0 is considered.The previously reported profile of diamagnetic drift current is altered by the introduction of inlet ion temperature,and the paramagnetic part is significantly suppressed.Moreover,a wide range of paramagnetic currents appear downstream due to the inward detachment of ions,which can also be reduced by increasing inlet ion temperature.Albeit considered in this paper,the azimuthal currents resulting from grad-B and curvature drift are still negligible in all cases of interest.The magnitude of diamagnetic azimuthal currents increases with amplifying Ti0,indicating a clear physical image of energy transformation from ion thermal energy to the directed kinetic energy through electromagnetic processes in the magnetic nozzle.Additionally,the magnetic inductive strength also has noticeable impacts on the azimuthal currents,the current magnitude tends to decrease as the magnetic field increases,and over-increment of it may result in larger divergence angles and lower nozzle efficiency.

关键词： Magnetic nozzle Azimuthal current Ion temperature Electric propulsion

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面向激光增材制造的仿生薄壁结构抗冲击研究

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工程设计学报 2024年第1期31卷 67-73页

作者：李佳宋梅利冯君汤海斌南京理工大学机械工程学院江苏南京210094 南京理工大学瞬态物理国家重点实验室江苏南京210094 南京理工大学智能制造学院江苏南京210094

冲击载荷是航空航天装备结构设计中不可忽视的因素,设计承载能力高、吸能特性好的薄壁结构是研究热点。综合骨骼和蜂窝的结构特征,基于Voronoi算法,开展了类蜂窝六边形结构伪随机排布;参考骨质内疏松外紧密的排布特征,进行分区设计,来... 详细信息

冲击载荷是航空航天装备结构设计中不可忽视的因素,设计承载能力高、吸能特性好的薄壁结构是研究热点。综合骨骼和蜂窝的结构特征,基于Voronoi算法,开展了类蜂窝六边形结构伪随机排布;参考骨质内疏松外紧密的排布特征,进行分区设计,来构造新型抗冲击结构。通过激光选区熔化钛合金及激光选区烧结碳纤维/PEEK(polyether ether ketone,聚醚醚酮)复合材料仿生薄壁结构和均布蜂窝结构的抗冲击仿真,对比了2种结构的吸能特性。仿真结果表明:相比于均布蜂窝结构,在轴向冲击条件下,激光选区熔化钛合金和激光选区烧结纤维/PEEK复合材料仿生薄壁结构的最大吸能量分别提高了17.7%和27.7%;在侧向冲击条件下,最大吸能量分别提高了422.6%和99.2%。所设计的仿生薄壁抗冲击结构在航空航天领域具有重要的应用前景。

关键词：薄壁结构仿生设计抗冲击激光选区熔化激光选区烧结

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Coupling plasma plume of a low-power magnetically shielded Hall thruster with a hollow cathode

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Chinese Journal of Aeronautics 2020年第12期33卷 3018-3026页

作者： Guangchuan ZHANG Junxue REN Wei LIANG Ning OUYANG Chao LU haibin tang School of Space and Environment Beihang UniversityBeijing 100083China School of Astronautics Beihang UniversityBeijing 100083China Shanghai Institute of Space Propulsion Shanghai 201112China Key Laboratory of Spacecraft Design Optimization&Dynamic Simulation Technologies Ministry of EducationBeijing 100083China Laboratory of Space Environment Monitoring and Information Processing Ministry of Industry and Information TechnologyBeijing 100083China

The coupling region of a Hall thruster with a hollow cathode is the region between the cathode and the thruster plume.The characteristics of plasma in that region are complicated and strongly associated with the thruster working conditions and the cathode position.In this paper,a laboratory 100 W class magnetically shielded Hall thruster was coupled with a hollow cathode.Optical imaging and electrostatic probe were employed to monitor and scan the plasma plume.Plume characteristics in the coupling region in non-self-sustained mode and self-sustained mode were compared.Evolution of the coupling plume with the cathode position was studied.Experiments show that,when turning the thruster into self-sustained mode or moving the cathode further away axially,the discharge current can be reduced by 6.4–10.6%restraining the electron current and improving ionization.In particular,when the cathode is moved further,the electron conduction near the channel walls is suppressed.The electron current is reduced by 27.4%and the ion beam current is increased by 7%.Overall,this work shows that the working mode of the thruster and the position of the cathode greatly affect the coupling plasma plume.Both play an important role in improving the utilizations of propellant and current.

关键词： Coupling region Electron conduction Hall thruster Hollow cathode Utilizations of propellant and current

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Origin of strong and narrow localized surface plasmon resonance of copper nanocubes

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Nano Research 2019年第1期12卷 63-68页

作者： Peng Zheng haibin tang Botong Liu Sujan Kasani Ling Huang Nianqiang Wu Departm ent of Mechanical and Aerospace Engineering West Virginia UniversityMorgantownWest Virginia 26506-6106USA Institute of Advanced Materials Nanjing Tech UniversityNanjing 211816China Lane Department of Computer Science and Electrical Engineering West Virginia UniversityMorgantownWest Virginia 26506USA

Inexpe nsive copper nano particles are generally thought to possess weak and broad localized surface plasm on resonance(LSPR).The,present experimental and theoretical studies show that tailoring the Cu nanoparticle to a cubic shape results in a single intense,narrow,and asymmetric LSPR line shape,which is even superior to round-shaped gold nanoparticles.In this study,the dielectric function of copper is decomposed into an interband transition component and a free-electron component.This allows interband transition-induced plasmon damping to be visualized both spectrally and by surface polarization charges.The results reveal that the LSPR of Cu nanocubes originates from the comer mode as it is spectrally separated from the interb and transitions.In additi on,the interband tran sitions lead to severe damping of the local electromagnetic field but the cubic corner LSPR mode survives.Cu nanocubes display an extinction coefficient comparable to the dipole mode of a gold nanosphere with the same volume and show a larger local electromagnetic field enhancement These results will guider-development of in expensive plasmonic copper-based nano materials.

关键词： copper nanocube localized surface plasmon resonance discrete dipole approximation interband transition

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创业导师对大学生创业能力影响的实证研究

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创新与创业教育 2024年第1期15卷 56-64页

作者：汤海滨广州新华学院管理学院广东广州510520

创业导师参与创业项目和指导创业者这两种行为对于提升大学生的内在创业能力和获取外部资源的能力有重要影响。实证研究发现,创业导师参与创业项目对于提高大学生获取外部资源的能力具有显著相关性,但是对于提升大学生的内在创业能力没... 详细信息

创业导师参与创业项目和指导创业者这两种行为对于提升大学生的内在创业能力和获取外部资源的能力有重要影响。实证研究发现,创业导师参与创业项目对于提高大学生获取外部资源的能力具有显著相关性,但是对于提升大学生的内在创业能力没有显著性关系;创业导师指导创业者对提升创业者内在创业能力和获取外部资源的能力都具有显著相关性。在此基础上,从创业导师和创业者的角度分别提出对策建议,即创业导师需要谨慎参与创业项目,与大学生建立更多联接,帮助潜在创业者树立信心,而创业者首先需要提高自身内在创业能力。

关键词：创业导师大学生创业能力

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Hexagonally arranged arrays of urchin-like Ag hemispheres decorated with Ag nanoparticles for surface-enhanced Raman scattering substrates

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Nano Research 2015年第7期8卷 2261-2270页

作者： haibin tang Guowen Meng Zhongbo Li Chuhong Zhu Zhulin Huang Zhaoming Wang Fadi Li Key Laboratory of Materials Physics and Anhui Key Laboratory of Nanomaterials and Nanotechnology Institute of Solid State Physics Chinese Academy of Sciences P. O. Box 1129 Hefei 230031 China University of Science and Technology of China Hefei 230026 China

The surface topography of noble metal particles is a significant factor in tailoring surface-enhanced Raman scattering （SERS） properties. Here, we present a simple fabrication route to hexagonally arranged arrays of surface-roughened urchin- like Ag hemispheres （Ag-HSs） decorated with Ag nanoparticles （Ag-NPs） for highly active and reproducible SERS substrates. The urchin-like Ag-HS arrays are achieved by sputtering Ag onto the top surface of a highly ordered porous anodic aluminum oxide （AAO） template to form ordered arrays of smooth Ag-HSs and then by electrodepositing Ag-NPs onto the surface of each Ag-HS. Owing to the ordered arrangement of the Ag-HSs and the improved surface roughness, the urchin-like hierarchical Ag-HS arrays can provide sufficient and uniform ＂hot spots＂ for reproducible and highly active SERS effects. Using the urchin-like Ag-HS arrays as SERS substrates, 10-7 M dibutyl phthalate （a member of plasticizers family） and 1.5 × 10-5 M PCB-77 （one congener of polychlorinated biphenyl, a notorious class of pollutants） are identified, showing promising potential for these substrates in the rapid recognition of organic pollutants.

关键词： Ag-hemisphere urchin-like surface roughness polychlorinated biphenyls (pcbs) surface-enhanced Raman scatteringsurface-enhanced Raman sers

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ZnO-nanotaper array sacrificial templated synthesis of noble-metal building-block assembled nanotube arrays as 3D SERS-substrates

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Nano Research 2015年第3期8卷 957-966页

作者： Chuhong Zhu Guowen Meng Qing Huang Xiujuan Wang Yiwu Qian Xiaoye Hu haibin tang Nianqiang Wu Key Laboratory of Materials Physics and Anhui Key Laboratory of Nanomaterials and Nanotechnology Institute of Solid State Physics Chinese Academy of Sciences Hefei 230031 China University of Science and Technology of China Hefei 230026 China Institute of Technical Biology and Agriculture Engineering Hefei Institutes of Physical Science Chinese Academy of Sciences Hefei 230031 China Department of Mechanical & Aerospace Engineering West Virginia University P.O. Box 6106 Morgantown WV26506 USA

这份报纸描述一个 ZnO-nanotaper 数组为有试管墙的 nanotubes 的数组的制造的合成途径由 Ag-nanoplates， Au-nanorods， Pt-nanothorns 或 Pd-nanopyramids 的大楼块装配了的牺牲的 templated，因此拥有高密度的 3D 在有 nano 尖端，... 详细信息

这份报纸描述一个 ZnO-nanotaper 数组为有试管墙的 nanotubes 的数组的制造的合成途径由 Ag-nanoplates， Au-nanorods， Pt-nanothorns 或 Pd-nanopyramids 的大楼块装配了的牺牲的 templated，因此拥有高密度的 3D 在有 nano 尖端，角落或边的附近的积木的 sub-10-nm 差距的热点。另外，这些层次 nanostructure 数组与富有的表面化学拥有高表面区域，对捕获 analyte 有益。Ag-nanoplateassembled nanotube 数组能被用作散布的敏感提高表面的拉曼(重量的单位) 有好信号一致性和重制度的底层。用如此的 Ag ，层次 nanostructure 作为重量的单位底层穿，不是仅仅有 10 14 M 玫瑰精 6G 识别，而且 10 7 M polychlorinated 联本基(印刷电路板，坚持的器官的污染物质的一个臭名昭著的班)被认出，并且甚至印刷电路板的二同种的物能在混合物被识别，在环境器官的污染物质的基于重量的单位的快速的察觉显示出材料的潜在的应用。

关键词：纳米管阵列 SERS 模板合成 ZnO 贵金属组装 3D 积木

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Polyacrylic acid sodium salt film entrapped Ag-nanocubes as molecule traps for SERS detection

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Nano Research 2014年第8期7卷 1177-1187页

作者： Zhulin Huang Guowen Meng Qing Huang Bin Chen Fei Zhou Xiaoye Hu Yiwu Qian haibin tang Fangming Han Zhaoqin Chu Key Laboratory of Materials Physics and Anhui Key Laboratory of Nanomaterials and Nanostructures Institute of Solid State Physics Chinese Academy of Sciences P. O. Box 1129 Hefei 230031 China University of Science and Technology of China Hefei 230026 China Key Laboratory of Ion Beam Bioengineering Hefei Institutes of Physical Science Chinese Academy of Sciences Hefei 23003 I China

提高表面的拉曼光谱学(重量的单位) 是为踪迹化学药品的一种快分析技术；然而，吸附 analytes 要求活跃重量的单位底层，因此为底层与需要的亲密关系限制目标种类到那些。这里我们现在的联网的 polyacrylic 酸钠盐(PAAS ) 电影骗诱 Ag-n... 详细信息

提高表面的拉曼光谱学(重量的单位) 是为踪迹化学药品的一种快分析技术；然而，吸附 analytes 要求活跃重量的单位底层，因此为底层与需要的亲密关系限制目标种类到那些。这里我们现在的联网的 polyacrylic 酸钠盐(PAAS ) 电影骗诱 Ag-nanocubes (作为 Ag-nanocubes@PAAS 表示了) 作为为有或没有高亲密关系的 analytes 的有效重量的单位底层。一次 analyte 水的答案在干燥 Ag-nanocubes@PAAS 底层上被扔，嗜酒的 PAAS 变得肿强迫 Ag-nanocubes 松开，当时在在 Ag-nanocubes 之中的空隙弥漫的 analytes。当弄干时， PAAS 缩小并且拉 Ag-nanocubes 回到他们的以前的聚集的状态，当 PAAS 网络为重量的单位察觉在在 Ag-nanocubes 之间的小差距耽搁 analytes 时。没有强壮的亲密关系，策略为 Ag 为不仅 singleanalytes 而且 multi-analytes 被证明有效，在环境在能吸附、非能吸附的污染物质的基于重量的单位的同时的 multi-analyte 察觉显示出它的潜力。

关键词：聚丙烯酸钠盐 SERS 立方体纳米检测盐膜表面增强拉曼光谱银

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在役高速公路大跨度斜拉桥荷载试验研究

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四川建材 2024年第2期50卷 203-205页

作者：张扬徐冰雷张杰王敏汤海彬江苏宿淮盐高速公路管理有限公司江苏淮安223001 苏交科集团股份有限公司江苏南京210000 长大桥梁安全长寿与健康运维全国重点实验室江苏南京210000

淮安大桥为大跨度双索面斜拉桥,已服役18年,为掌握大桥当前结构状态和受力性能,对大桥进行荷载试验,针对主梁最大正负弯矩、主塔最大弯矩、主梁挠度、塔偏等设计加载工况。结果表明,淮安大桥测试截面的平均应变、挠度及塔顶偏位的校验... 详细信息

淮安大桥为大跨度双索面斜拉桥,已服役18年,为掌握大桥当前结构状态和受力性能,对大桥进行荷载试验,针对主梁最大正负弯矩、主塔最大弯矩、主梁挠度、塔偏等设计加载工况。结果表明,淮安大桥测试截面的平均应变、挠度及塔顶偏位的校验系数均处在合理范围内,相对残余均小于20%,大桥处于弹性工作阶段,受力性能良好,满足设计荷载的正常使用要求。

关键词：桥梁工程大跨度斜拉桥荷载试验承载能力评定

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