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Simulation of the continuous casting process in a mold of free-cutting steel 38MnVS based on a MiLE method

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International Journal of Minerals,Metallurgy and Materials 2011年第5期18卷 562-569页

作者： Fu-mingWang yun-jin Xia jin-long Wang Guo-zhong Li School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China Key Lab of the Ministry of Education of China for Ecologic and Recycle Metallurgy University of Science and Technology Beijing Beijing 100083 China Jiangyin Xingcheng Iron and Steel Co. Ltd. Jiangyin 214429 China

A new method called mixed Lagrangian and Eulerian （MiLE） method was used to simulate the continuous casting process in a mold of free-cutting steel *** simulation results are basically in agreement with experimental data in the literature,achieving the three-dimensional visualization of temperature distribution,melt flow,shell thickness,and stress distribution of blooms in a *** is shown that the flow velocity of steel melt becomes smaller gradually as the casting *** the flow reaches a certain depth,two types of flow patterns can be observed in the upper zone of the *** first flow pattern is to flow downwards,and the second one is to flow upwards to the *** corner temperature is higher,and the thickness is thinner than those in the *** effective stress in the corner area is much bigger than that in the mid-face,indicating that the corner area is the dangerous zone of cracking.

关键词： free-cutting steel melt flow continuous casting computer simulation

MELINIKOV’S METHOD FOR NON-LINER ROLLING MOTIONS OF A FLOODED SHIP

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Journal of Hydrodynamics 2005年第5期17卷 580-584页

作者： PU jin-yun ZHANG Wei-kang jin Tao JI Gang College of Ship and Power University of Naval Engineering Wuhan 430033 China

To investigate the rolling motions of a flooded ship, non linear coupled dynamics of roll and flooded water are derived using Lagrange＇s principle. Decoupling the coupied equations gives a single-freedom ordinary differential equation, which can describe the rolling motion of the flooded ship. Melinkov＇s method is used to predict the chaos behavior of the ship. Numerical computations are performed for three statuses of a ship model. The comparison of the results shows that the more cabins flooded, the more likely a chaos phenomenon will appear.

关键词： ship flooding roll Melinikov' method

Prediction of Melt Pool Dimension and Residual Stress Evolution with Thermodynamically-Consistent Phase Field and Consolidation Models during Re-Melting Process of SLM

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Computers, Materials & Continua 2021年第1期66卷 87-112页

作者： Kang-Hyun Lee Gun jin yun Department of Aerospace Engineering Seoul National UniversitySeoul08826South Korea Institute of Advanced Aerospace Technology Seoul National UniversitySeoul08826South Korea

Re-melting process has been utilized to mitigate the residual stress level in the selective laser melting(SLM)process in recent ***,the complex consolidation mechanism of powder and the different material behavior after the first laser melting hinder the direct implementation of the re-melting *** this work,the effects of re-melting on the temperature and residual stress evolution in the SLM process are investigated using a thermo-mechanically coupled finite element *** degree of consolidation is incorporated in the energy balance equation based on the thermodynamically-consistent phase-field *** drastic change of material properties due to the variation of temperature and material state is also *** the proposed simulation framework,the single-track scanning is simulated first to predict the melt pool dimension and validate the proposed model with the existing experimental *** obtained thermal histories reveal that the highest cooling rate is observed at the end of the local solidification time which acts as an important indicator for the alleviation of temperature ***,the scanning of a whole single layer that consists of multiple tracks is simulated to observe the stress evolution with several re-melting *** the full melting of powder material in the first scanning process,the increase of residual stress level is observed with one remelting ***,the predicted stress level with the re-melting process shows the variation trend attributable to the accumulated heat in the *** numerical issues and the detailed implementation process are also introduced in this paper.

关键词： Selective laser melting thermo-mechanical analysis Ti-6Al-4V additive manufacturing re-melting residual stress

Simulation of Secondary Dendritic Arm Spacing of Free Cutting Steel 38MnVS

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Journal of Iron and Steel Research(International) 2011年第6期18卷 54-60,73页

作者： XIA yun-jin WANG Fu-ming WANG jin-long School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China

The secondary dendritic arm spacing （SDAS） of free cutting steel 38MnVS during continuous casting process was simulated based on a Mixed Lagrangian and Eulerian Method （MILE Method） and SDAS model. The simulation results are basically in agreement with measured ones. The effect of composition, superheat and casting speed on SDAS are studied, and the relationship between SDAS and interdendritic segregation is discussed. The results show that SDAS increases with increasing carbon and silicon content, and decreases with increasing manganese and sulfur content. The increase of superheat and casting speed also makes SDAS increase. The permeability of co lumnar mushy zone which is parallel to the primary dendritic arms is calculated based on Carman-Kozeny relationship, and the increase of SDAS makes the permeability increase, which exacerbates interdendritic segregation of columnar crystal zone.

关键词： MiLE method secondary dendritic arm spacing permeability interdendritic segregation

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元宇宙驱动的企业数智化决策模式创新

电信工程技术与标准化 2024年第7期37卷 87-92页

作者：傅云瑾王浩亮李凯苑文博王姝力吴以頔中国移动通信集团设计院有限公司北京100080

元宇宙作为大数据、云计算、物联网、区块链、移动通信等新一代信息通信技术集成和数智化发展的愿景蓝图,为各行各业带来了万亿规模的全新机遇,同时也高效赋能企业的数智化转型发展。企业决策模式如何适应元宇宙等新型数智化技术发展已... 详细信息

元宇宙作为大数据、云计算、物联网、区块链、移动通信等新一代信息通信技术集成和数智化发展的愿景蓝图,为各行各业带来了万亿规模的全新机遇,同时也高效赋能企业的数智化转型发展。企业决策模式如何适应元宇宙等新型数智化技术发展已成为管理理论关注热点。通过元宇宙背景下的智能决策诉求和企业决策模式变革方向分析,本文提出了元宇宙背景下企业决策模式的3点创新路径,即分阶段推进技术变革、加强“平台化+实体化”组织变革和推动在线智慧管理模式变革,并以ARK元宇宙办公平台为例说明企业数智化转型的发展趋势,通过打通生产与管理全流程的数据链并提高产品效率,实现企业在业务、生产、营销和运营管理全方位的数智化转型。

关键词：元宇宙决策诉求决策模式数智化转型

SDCC: software-defined collective communication for distributed training

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Science China(Information Sciences) 2024年第9期67卷 105-125页

作者： Xin jin Zhen ZHANG yunshan JIA yun MA Xuanzhe LIU School of Computer Science Peking University Department of Computer Science and Technology Johns Hopkins University

Communication is crucial to the performance of distributed training. Today's solutions tightly couple the control and data planes and lack flexibility, generality, and performance. In this study, we present SDCC, a software-defined collective communication framework for distributed training. SDCC is based on the principle of modern systems design to effectively decouple the control plane from the data *** abstracts the operations for collective communication in distributed training with dataflow operations and unifies computing and communication with a single dataflow graph. The abstraction, together with the unification, is powerful: it enables users to easily express new and existing collective communication algorithms and optimizations, simplifies the integration with different computing engines(e.g., Py Torch and Tensor Flow) and network transports(e.g., Linux TCP and kernel bypass), and allows the system to improve performance by exploiting parallelism exposed by the dataflow graph. We further demonstrate the benefits of SDCC in four use cases.

关键词： machine learning systems distributed training deep learning collective communication software-defined networking

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SH2-B beta upregulates the expression of interleukin-1 beta in lung and visceral primary afferent neurons in asthmatic mice

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Neural Regeneration Research 2011年第34期6卷 2703-2707页

作者： jinping Qi Xiaojie Wang yun jin Department of Anatomy Shenyang Medical College Shenyang 110034 Liaoning Province China

A previous study by our research group showed that nerve growth factor is involved in the onset of asthma through regulating SH2-Bβ expression in the lung and visceral primary afferent neurons of asthmatic mice. This study sought to assess the expression level of interleukin-1β in primary afferent neurons in C7-T5 spinal ganglia, spinal cord and lung in asthmatic mice after blockage of SH2-Bβ. The levels of interleukin-1β protein in primary afferent neurons in the C7-T5 spinal ganglia and lung were decreased, and interleukin-1β mRNA expression also down-regulated in the spinal cord, medulla oblongata and lung tissue after blockage of SH2-Bβ. Our findings indicate that SH2-Bβ can upregulate the expression of interleukin-1β in C7-T5 spinal ganglia, spinal cord and lung of asthmatic mice.

关键词： SH2-Bβ interleukin-1β asthma primary afferent neurons spinal ganglia afferent nerve pathway

Crystal Structure of a Nickel(II) Complex with Asymmetric _L-Histidine Ligand

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Chinese Journal of Structural Chemistry 2006年第9期25卷 1047-1050页

作者： jin Yi CHE yun-Xia ZHENG Ji-Min Department of Chemistry Nankai University Tianjin 300071 China

A novel nickel（Ⅱ） complex with L-histidine has been synthesized and solved by single-crystal X-ray diffraction analysis at physiological pH. The title complex （C7H16NiN4O6S, Mr = 343.01） crystallizes in monoclinic, space group P21 with a = 7.2194（7）, b = 7.5968（7）, c = 12.2797（11） A, β = 93.3110（10）°, V = 672.35（11） A^3, Z = 2, Dc= 1.694 g/cm^3, F（000） = 356, μ（MoKα） = 1.626 mm^-1, T = 293（2） K, the final R = 0.0184 and wR = 0.0426 for 2207 observed reflections with 1 〉 2σ（I）. The complex provides insights into a possible structural arrangement between nickel （Ⅱ） and L-histidine which may be physiologically important and abundantly present in biological systems.

关键词： crystal structure synthesis L-histidine nickel physiological pH

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基于课程思政的药物分析教学改革与实践

海峡药学 2024年第7期36卷 50-53页

作者：张敏刘惠娟王芳王红娟靳佩芸邹传宗甘肃医学院甘肃平凉744000

目的紧密围绕《高等学校课程思政建设指导纲要》,以核心价值观塑造、职业素养提升和科学精神渗透为抓手,系统提升药物分析课程思政教学效果。方法6K突出符合药物分析课程思政总体目标的指挥地位,深入挖掘与专业紧密结合的思政元素,拓展... 详细信息

目的紧密围绕《高等学校课程思政建设指导纲要》,以核心价值观塑造、职业素养提升和科学精神渗透为抓手,系统提升药物分析课程思政教学效果。方法6K突出符合药物分析课程思政总体目标的指挥地位,深入挖掘与专业紧密结合的思政元素,拓展教学方法,探索评价手段,共同促进教学改革。结果改革后的课程思政内涵丰富,目标统一,与专业内容无缝衔接。学生课堂表现气氛活跃,兴趣和参与度明显提高。结论课程思政是实现立德树人的主要途径。药物分析作为药学专业的核心专业课程,通过引导培养学生正确的人生观价值观,严谨务实的工作作风、强烈社会责任感、坚持不懈的科研精神,对保障人民安全用药起到至关重要的作用。

关键词：课程思政药物分析教学改革