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Study on Squeeze Casting Metal-zirconium Composite Die Material by Hot Press Sintering

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Journal of Wuhan University of Technology(Materials Science) 2021年第4期36卷 484-489页

作者： sun yonggen DU Zhiming CHEN Lili FEI Yanhan CHENG Yuansheng National Key Laboratory for Precision Hot Processing of Metals Harbin 150001China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China

ZrO_(2)-5CrMnMo composite samples were prepared by hot press *** NiCoCrAlY powders were used as the bonding layer and the different mixtures of NiCoCrAlY alloy and 3YSZ (3mol% yttria stabilized zirconia) ceramic powders were used as the transition layers,the connection between zirconia ceramic and 5CrMnMo steel were *** composite samples with different structures were fabricated by heat spraying and hot press *** and thermal shock cycle tests were conducted to characterize connection strength and thermal shock resistance of these *** shear strength reached 95.69 MPa,and the heating shock cycles achieved to the maximum value of 27.7 *** and connection interfaces were analyzed by scanning electron *** hardness and wearing resistance of 3YSZ coat and 5CrMnMo substrate were compared,and the heat insulation property of composite samples were also *** is shown that these composite materials fabricated in this research are benefited to be used as squeeze casting dies.

关键词： composite materials hot press sintering thermal shock resistance thermal insulation squeeze casting

Beach Morphology and Coastline Evolution in the Southern Bohai Strait

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Journal of Ocean University of China 2015年第5期14卷 803-815页

作者： ZHANG Wei WU Jianzheng LI Weiran ZHU Longhai HU Rijun JIANG shenghui sun yonggen WANG Huijuan College of Marine Geoscience Ocean University of China Qingdao Marine Geological Engineering Investigation Institute Key Laboratory of Submarine Geosciences and Prospecting Techniques Ministry of EducationOcean University of China First Institute of Oceanography SOA Qingdao Boyan Marine Environment Science & Technology Co.Ltd.

The beach studied in this paper spans a length of 51 km and is one of several long sandy beaches in the southern Bohai Strait. Due to the obstruction of islands in the northeast and the influence of the underwater topography, the wave environment in the offshore area is complex; beach types and sediment transport characteristics vary along different coasts. The coastlines extracted from six aerial photographs in different years were compared to demonstrate the evolving features. Seven typical beach profiles were selected to study the lateral beach variation characteristics. Continuous wind and wave observation data from Beihuangcheng ocean station during 2009 were employed for the hindcast of the local wave environment using a regional spectral wave model. Then the results of the wave hindcast were incorporated into the LITDRIFT model to compute the sediment transport rates and directions along the coasts and analyze the longshore sand movement. The results show that the coastline evolution of sand beaches in the southern Bohai Strait has spatial and temporal variations and the coast can be divided into four typical regions. Region （1）, the north coast of Qimudao, is a slightly eroded and dissipative beach with a large sediment transport rate; Region （II）, the southwest coast of Gangluan Port, is a slightly deposited and dissipative beach with moderate sediment transport rate; Region （III）, in the central area, is a beach that is gradually transformed from a slightly eroded dissipative beach to a moderately or slightly strong eroded bar-trough beach from west to east with a relatively moderate sediment transport rate. Region （IV）, on the east coast, is a strongly eroded and reflective beach with a weak sediment transport rate. The wave conditions exhibit an increasing trend from west to east in the off- shore area. The distribution of the wave-induced current inside the wave breaking region and the littoral sediment transport in the nearshore region exhibit a gradua

关键词： sand beach coastline evolution profile feature wave hind-casting wave-induced current littoral sediment transport

Microstructure and Mechanical Properties of Al-5Cu-4.5Mg-2.5Zn Squeeze Cast Alloy

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Journal of Wuhan University of Technology(Materials Science) 2022年第5期37卷 977-985页

作者： sun yonggen WANG Yanchun SU Yanni SONG Xujie DU Lanjun CHENG Yuansheng DU Zhiming National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin150001China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China Beijing North Vehicle Group Co.Ltd. Beijing100072China Beijing Aerospace Propulsion Institute Beijing100076China

Al-5Cu-4.5Mg-2.5Zn alloy was prepared and the alloy ingots were fabricated by squeeze casting in this *** these negative effects of composition segregation and coarse second phases,some heat treatments were adopted in this ***,element distribution,phase constitutions and mechanical properties of Al-5Cu-4.5Mg-2.5Zn alloy ingots before and after heat treatments were *** was discovered that these heat treatments would influence and extremely optimize the microstructures and properties of Al-5Cu-4.5Mg-2.5Zn *** some residual S (Al_(2)CuMg) phase and a few of η phase,the precipitate free zone (PFZ) and the Guinier Preston zone (GPZ) formed in the *** was also found that θ′′ (Al_(2)Cu) and η′′ (MgZn_(2)) phases formed and kept a consistent relationship with the aluminum *** the result,these properties of ultimate tensile strength (UTS),percentage of elongation and Brinell hardness (HB) were greatly *** UTS,percent of elongation and HB were 469 MPa,8.1% and 208 N/mm^(2),respectively.

关键词： Al-Cu-Mg-Zn alloy squeeze casting heat treatments second phases mechanical properties

Effect of Zn/Mg/Cu Additions on Hot Cracking Tendency and Performances of Al-Cu-Mg-Zn Alloys for Liquid Forging

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Journal of Wuhan University of Technology(Materials Science) 2020年第1期35卷 176-182页

作者：孙永根杜之明 SU Yanni CHENG Yuansheng LIU Yongwang National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China

During the process of liquid forging, a host of hot cracking defects were found in the Al-CuMg-Zn aluminum alloy. Therefore, mechanical tests and analyses by optical microscope, scanning electron microscope, and X-ray diffraction were performed to research the influences of zinc, magnesium, and copper(three main alloying elements) on hot cracking tendency and mechanical properties. It was concluded that all the three alloying elements exerted different effects on the performances of newly designed alloys. And the impact of microstructures on properties of alloys was stronger than that of solution strengthening. Among new alloys, Al-5 Cu-4.5 Mg-2.5 Zn alloy shows better properties as follows: σb=327 MPa, δ=2.7%, HB=107 N/mm^2, and HCS=40.

关键词： liquid forging Al-Cu-Mg-Zn alloys mechanical properties hot cracking tendency

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钦州湾悬浮泥沙特征

海洋地质与第四纪地质 2016年第1期36卷 79-86页

作者：孙永根丰爱平王恩康王勇智孙惠凤国家海洋局第一海洋研究所青岛266061

钦州湾由于湾内外特殊的海洋动力、泥沙来源和地形地貌条件,导致海湾悬浮泥沙特性存在较大差异。通过2007年和2010年钦州湾13个站位的实测悬浮泥沙含沙量数据,总结了钦州湾的泥沙来源,分析了钦州湾悬浮泥沙的空间分布特征、运移趋势和... 详细信息

钦州湾由于湾内外特殊的海洋动力、泥沙来源和地形地貌条件,导致海湾悬浮泥沙特性存在较大差异。通过2007年和2010年钦州湾13个站位的实测悬浮泥沙含沙量数据,总结了钦州湾的泥沙来源,分析了钦州湾悬浮泥沙的空间分布特征、运移趋势和输沙能力。研究结果表明,钦州湾泥沙主要来自河流输沙、海向来沙及岸滩侵蚀;水体含沙量最大值空间分布整体表现出"外湾>内湾>湾颈"的特点,平均值由内湾到外湾逐渐减小;水体垂向平均含沙量最大值出现层位不同,内湾表底层平均含沙量趋于一致,但中层略大,而外湾由表层至底层存在渐进变化;潮流强度、地形特征及泥沙来源是影响悬浮泥沙空间分布的主要因素;悬浮泥沙输运主要受潮流控制,输沙强度呈"湾颈>外湾>内湾"特点,总体输沙趋势由湾顶向湾外、沿落潮流由北向南输运。

关键词：悬浮泥沙空间分布悬沙输运钦州湾

Safe flight corridor constrained sequential convex programming for efficient trajectory generation of fixed-wing UAVs

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Chinese Journal of Aeronautics 2025年第1期38卷 537-550页

作者： Jing sun Guangtong XU Zhu WANG Teng LONG Jingliang sun School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Huzhou Institute Zhejiang UniversityHuzhou 313000China Department of Automation North China Electric Power University(Baoding)Baoding 071003China

Generating dynamically feasible trajectory for fixed-wing Unmanned Aerial Vehicles(UAVs)in dense obstacle environments remains computationally *** paper proposes a Safe Flight Corridor constrained Sequential Convex Programming(SFC-SCP)to improve the computation efficiency and reliability of trajectory ***-SCP combines the front-end convex polyhedron SFC construction and back-end SCP-based trajectory optimization.A Sparse A^(*)Search(SAS)driven SFC construction method is designed to efficiently generate polyhedron SFC according to the geometric relation among obstacles and collision-free *** transforming the nonconvex obstacle-avoidance constraints to linear inequality constraints,SFC can mitigate infeasibility of trajectory planning and reduce computation ***,SCP casts the nonlinear trajectory optimization subject to SFC into convex programming subproblems to decrease the problem *** addition,a convex optimizer based on interior point method is customized,where the search direction is calculated via successive elimination to further improve *** experiments on dense obstacle scenarios show that SFC-SCP can generate dynamically feasible safe trajectory *** studies with state-of-the-art SCP-based methods demonstrate the efficiency and reliability merits of ***,the customized convex optimizer outperforms off-the-shelf optimizers in terms of computation time.

关键词： Fixed-wing unmanned aerial vehicle Efficient trajectory planning Safe flight corridor Sequential convex programming Customized convex optimizer

Engineering nanoparticle structure at synergistic Ru-Na interface for integrated CO_(2)capture and hydrogenation

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Journal of Energy Chemistry 2025年第1期100卷 779-791页

作者： Hanzi Liu Ling Cen Xinlin Xie Lei Liu Zhao sun Zhiqiang sun Hunan Engineering Research Center of Clean and Low-Carbon Energy Technology School of Energy Science and EngineeringCentral South UniversityChangsha 410083HunanChina

The development of dual functional material for cyclic CO_(2)capture and hydrogenation is of great significance for converting diluted CO_(2)into valuable fuels,but suffers from kinetic limitation and deactivation of adsorbent and ***,we engineered a series of RuNa/γ-Al_(2)O_(3)materials,varying the size of ruthenium from single atoms to clusters/*** coordination environment and structure sensitivity of ruthenium were quantitatively investigated at atomic *** findings reveal that the reduced Ru nanoparticles,approximately 7.1 nm in diameter with a Ru-Ru coordination number of 5.9,exhibit high methane formation activity and selectivity at 340°*** Ru-Na interfacial sites facilitate CO_(2)migration through a deoxygenation pathway,involving carbonate dissociation,carbonyl formation,and ***-situ experiments and theoretical calculations show that stable carbonyl intermediates on metallic Ru nanoparticles facilitate heterolytic C–O scission and C–H bonding,significantly lowering the energy barrier for activating stored CO_(2).

关键词： CO_(2)capture Hydrogenation Ru-Na interface Dual functional material Reaction mechanism

Penalty Function-Based Distributed Primal-Dual Algorithm for Nonconvex Optimization Problem

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IEEE/CAA Journal of Automatica Sinica 2025年第2期12卷 394-402页

作者： Xiasheng Shi Changyin sun IEEE the Engineering Research Center of Autonomous Unmanned System Technology Ministry of Education Anhui University the School of Artificial Intelligence Anhui University Anhui Provincial Engineering Research Center for Unmanned System and Intelligent Technology Anhui University the Anhui Key Laboratory Industrial Energy-Saving and Safety Anhui University

This paper addresses the distributed nonconvex optimization problem, where both the global cost function and local inequality constraint function are nonconvex. To tackle this issue, the p-power transformation and penalty function techniques are introduced to reframe the nonconvex optimization problem. This ensures that the Hessian matrix of the augmented Lagrangian function becomes local positive definite by choosing appropriate control parameters. A multi-timescale primal-dual method is then devised based on the Karush-Kuhn-Tucker(KKT) point of the reformulated nonconvex problem to attain convergence. The Lyapunov theory guarantees the model's stability in the presence of an undirected and connected communication network. Finally, two nonconvex optimization problems are presented to demonstrate the efficacy of the previously developed method.

关键词： Constrained optimization Karush-Kuhn-Tucker (KKT) point nonconvex p-power transformation

The Caroline Plate and plate subduction along the Mussau Trench

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Science China Earth Sciences 2025年第2期68卷 639-642页

作者： Weidong sun Tianyu ZHANG Center of Deep Sea Research&Key Laboratory of Marine Geology and Environment Key Laboratory of Ocean Observation and ForecastingInstitute of OceanologyChinese Academy of SciencesQingdao 266071China Laoshan Laboratory Qingdao 266237China University of Chinese Academy of Sciences Beijing 100049China

1. Introduction The oldest oceanic crust with ages up to 200 Ma, is subducting along the West Pacific Convergent margin. Interestingly, it is right next to a Cenozoic microplate, the Caroline Plate. The Mussau Trench ... 详细信息

关键词： subduction Cenozoic oceanic

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