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High-enthalpy hypersonic flows

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Advances in Aerodynamics 2020年第1期2卷 373-411页

作者： joseph j.s.shang Hong Yan Wright state University 3640 Colonel Glenn HighwayDaytonOH 45435USA school of Power and Energy Northwestern Polytechnical University127West Youyi RoadXi’an 710072China

Nearly all illuminating classic hypersonic flow theories address aerodynamic phenomena as a perfect gas in the high-speed range and at the upper limit of continuum gas *** hypersonic flow is quantitatively defined by the Mach number independent principle,which is derived from the asymptotes of the Rankine-Hugoniot ***,most hypersonic flows encounter strong shock-wave compressions resulting in a high enthalpy gas environment that always associates with nonequilibrium thermodynamic and quantum chemical-physics *** this circumstance,the theoretic linkage between the microscopic particle dynamics and macroscopic thermodynamics properties of gas is *** the air mixture is ionized to become an electrically conducting medium,the governing physics now ventures into the regimes of quantum physics and ***,the hypersonic flows are no longer a pure aerodynamics subject but a multidisciplinary *** order to better understand the realistic hypersonic flows,all pertaining disciplines such as the nonequilibrium chemical kinetics,quantum physics,radiative heat transfer,and electromagnetics need to bring forth.

关键词： Hypersonic flow Nonequilibrium chemical kinetics Ionization Quantum mechanics Electromagnetics Radiation

Correction to:High-enthalpy hypersonic flows

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Advances in Aerodynamics 2020年第1期2卷 454-454页

In the original publication of this article[1],the author indicated the Eq.(2-1)and Eq.(2-6)are not *** correct Equations are.

关键词： enthalpy flows article

Electrostatic-Aerodynamic Compression in Hypersonic Cylindrical Inlet

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Communications in Computational Physics 2008年第9期4卷 838-859页

作者： j.s.shang Department of Mechanics and Materials Engineering Wright State UniversityDaytonOH 45435USA.

Hypersonic magneto-fluid-dynamic interaction has been successfully performed as a virtual leading-edge strake and a virtual cowl of a rectangular *** a side-by-side experimental and computational study,the magnitude of the induced compression was found to depend on configuration and electrode *** better understand the interacting phenomenon the present investigation is focused on a direct current discharge at the leading edge of a cylindrical inlet for which validating experimental data is *** present computational result is obtained by solving the magneto-fluid-dynamics equations at the low magnetic Reynolds number limit and using a nonequilibrium weakly ionized gas model based on the drift-diffusion *** numerical simulation provides a detailed description of the intriguing *** validation with experimental measurements,the computed results further quantify the effectiveness of a magneto-fluid-dynamic compression for a hypersonic cylindrical inlet.A minuscule power input to a direct current surface discharge of 8.14 watts per square centimeter of electrode area produces an additional compression of 6.7 percent for a constant cross-section cylindrical inlet.

关键词： Magnetohydrodynamics hypersonic flows

simulating Microwave Radiation of Pyramidal Horn Antenna for Plasma Diagnostics

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Communications in Computational Physics 2006年第4期1卷 677-700页

作者： j.s.shang Mechanical and Material Engineering Department Wright State UniversityDayton Ohio 45435USA

Computational simulation of the radiating structure of a microwave from a pyramidal horn has been successfully *** simulation capability is de-veloped for plasma diagnostics based on a combination of three-dimensional Maxwell equations in the time domain and the generalized Ohm’s *** transverse electrical electromagnetic wave of the TE1,0 mode propagating through a plasma medium and transmitting from antenna is simulated by solving these governing *** results were obtained for a range of plasma transport properties including electrical con-ductivity,permittivity,and plasma *** a guided microwave passing through plasma of finite thickness,the reflections at the media interfaces exhibit substantial distortion of the electromagnetic field within the thin *** radiating simulation,the edge diffraction at the antenna aperture is consistently captured by numerical so-lutions and reveals significant perturbation to the emitting *** numerical solution reaffirms the observation that the depth of the plasma is a critical parameter for diagnostics measurement.

关键词： Plasma diagnostics microwave simulation antenna

Effects of carbon content on the microstructure and tensile properties of a low-density steel

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International journal of Minerals,Metallurgy and Materials 2025年第2期32卷 391-401页

作者： Yongxuan shang Mingyu Fan shuyong jiang Zhongwu Zhang Key Laboratory of superlight Materials and surface Technology Ministry of EducationCollege of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China state Key Laboratory of Metal Material for Marine Equipment and Application Iron&Steel Research Institute of Ansteel Group CorporationAnshan 114009China

Carbon can change the phase components of low-density steels and influence the mechanical *** this study,a new method to control the carbon content and avoid the formation ofδ-ferrite by decarburization treatment was *** microstructural changes and mechanical characteristics with carbon content induced by decarburization were systematically ***-jaoul(C-j)analysis was employed to examine the work hardening characteristics during the tensile *** decarburization by heat treatments,the carbon content within the austenite phase decreased,while Mn and Al were almost unchanged;this made the steel with full austenite transform into the austenite and ferrite dual ***,(Ti,V)C carbides existed in both matrix phase and the mole fraction almost the *** addition,the formation of other carbides *** loss induced a decrease in strength due to the weakening of the carbon solid *** the steel with the single austinite,the deformation mode of austenite was the dislocation planar glide,resulting in the formation of *** the dual-phase steel,the deformation occurred by the dislocation planar glide of austenite first,with the increase in strain,the cross slip of ferrite took place,forming dislocation cells in *** the late stage of deformation,the work hardening of austinite increased rapidly,while that of ferrite increased slightly.

关键词： low-density steels carbon content decarburization strengthening mechanisms work hardening behavior

synthesis of single-Crystal TiO_2 Nanowire Using Titanium Monoxide Powder by Thermal Evaporation

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journal of Materials science & Technology 2012年第5期28卷 385-390页

作者： Z.G.shang Z.Q.Liu P.j.shang j.K.shang shenyang National Laboratory for Materials science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

TiO 2 nanowires were synthesized successfully in a large quantity by thermal evaporation using titanium monoxide powder as precursor. X-ray diffraction results showed that all the products were pure rutile phase of TiO 2 . According to microstructural observations, the nanowires have two typical morphologies, a long straight type and a short tortuous type. The straight nanowires were obtained at a wide temperature range of 900–1050 ℃, while the tortuous ones were formed below 900 ℃. Transmission electron microscopy characterization revealed that both the straight and the tortuous nanowires are single-crystal rutile TiO 2 . The preferential growth direction of the nanowires was determined as [110] orientation according to electron diffraction and high-resolution image analyses. The morphological change of TiO 2 nanowires was discussed by considering the different atomic diffusion rates of Ti atoms caused by the phase transformation in Ti substrate at around 900 ℃.

关键词： Rutile-TiO 2 Alloy nanowires Transmission electron microscopy (TEM) characterization Crystal structure identification Growth mechanism Thermal evaporation

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基于视频游戏的空间能力测评

心理科学进展 2025年第1期33卷 11-24页

作者：尚俊杰石祝沈科杰北京大学教育学院学习科学实验室北京100871

空间能力是个体对客体或空间图形在头脑中进行识别、编码、贮存、表征、分解组合和抽象概括的能力,是个体理解自身所处环境并解决问题的认知基础。准确、便捷、有效地测评空间能力,对增强sTEM教育教学水平和人才培养质量都具有重要意义... 详细信息

空间能力是个体对客体或空间图形在头脑中进行识别、编码、贮存、表征、分解组合和抽象概括的能力,是个体理解自身所处环境并解决问题的认知基础。准确、便捷、有效地测评空间能力,对增强sTEM教育教学水平和人才培养质量都具有重要意义。由于空间能力受多因素共同作用,具有复杂性、多维度、内隐性的特点,使得利用计算机评价空间能力比较困难。本研究旨在准确、有效、大规模地测评空间能力,将使用多模态学习分析方法探索学习者空间认知行为表现特征,并基于视频游戏环境研发空间能力隐形测评关键技术与工具。具体包括:1)构建空间能力内在表征框架和评价指标体系;2)基于多模态学习分析构建学习者空间能力行为表现模型;3)探索视频游戏影响空间能力的关键因素,并使用游戏引擎开发基于视频游戏的测评工具;4)使用以证据为中心的设计框架和贝叶斯网络模型,开发并部署能够推断和预测空间能力的测评算法;5)在实验室和真实课堂情境开展实证研究,验证测评工具有效性。研究成果将有利于理解人类空间认知过程和行为表现,拓展和丰富空间能力相关理论,并为大规模数字化测评提供关键技术支撑。

关键词：基于游戏的测评空间能力多模态学习分析游戏化学习隐形测评

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Role of Wetting Front in Dewetting of Liquid solder Drop on Cu Thin Films

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journal of Materials science & Technology 2010年第3期26卷 200-205页

作者： Wei Liu Lei Zhang j.K. shang shenyang National Laboratory for Materials science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Department of Materials science and Engineering University of Illinois at Urbana-Champaign Urbana IL 61801 USA

The thermodynamic conditions for dewetting of a liquid solder drop on copper thin films were examined under a hot-stage optical microscope in a flowing protective *** of liquid solder was found to depend strongly on the copper film thickness and preceded by spalling of Cu 6 sn 5 intermetallic ***,the loss of interfacial bonding by spalling was not sufficient to cause immediate dewetting of solder drops if the wetting tip was still strongly bonded to the copper *** introducing a pinning force on the wetting front,a sufficient condition was found from a force balance analysis for dewetting of the liquid solder drop,in general agreement with the experimental results.

关键词： Dewetting solder spalling Film thickness

First-principles Investigation of Bi segregation at the solder Interface of Cu/Cu_3sn(010)

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journal of Materials science & Technology 2010年第12期26卷 1057-1062页

作者： X.Y. Pang Z.Q. Liu s.Q. Wang j.K. shang shenyang National Laboratory for Materials science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Department of Materials science and Engineering University of Illinois at Urbana-Champaign IL 61801 USA

Density functional theory was employed to investigate the bismuth segregation at Cu/Cu3sn（010） interface. Five initial constructions were introduced by adopting the adhesion energy criterion. Among them, the so-called ＂between-Cu＂ construction in which the interface Cu atoms of Cu slab locate along Cu-Cu bond direction in Cu3sn slab was found to be the most energy-favored at an adhesion energy of 1.96 j/m^2. Based on this construction, five possible segregation sites were examined, and the most likely segregation site was determined with adhesion energy as low as 1.06 j/m^2, which was almost half of the initial one. Comparing with other sitest adhesion energies, it was concluded that size effect took a large part in embrittlement. The analyses of atomic structure and electronic density revealed that the slabs shifted away from interfaces due to bismuth segregation, and the atoms around Bi atom were Dressed away. This calculated work agreed aualitativelv with reported experimental results.

关键词： First-principles calculation segregation Bismuth Interface snBi solder