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汽车用2024-T351铝合金的动态力学行为各向异性

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材料导报 2024年第8期38卷 213-221页

作者：左志东刘先斌刘吉波汪小锋陈剑斌宁波大学机械工程与力学学院浙江宁波315211 宁波展慈新材料科技有限公司浙江宁波315338 宁波大学冲击与安全工程教育部重点实验室浙江宁波315211

采用拉伸机、扫描电子显微镜(SEM)及光学显微镜(OM)等研究了汽车用2024-T351铝合金的动态力学行为各向异性与微观组织演变。结果表明,2024-T351铝合金表现出明显的各向异性且应变率对力学性能与微观组织有一定的影响。相同应变率下,0°... 详细信息

采用拉伸机、扫描电子显微镜(SEM)及光学显微镜(OM)等研究了汽车用2024-T351铝合金的动态力学行为各向异性与微观组织演变。结果表明,2024-T351铝合金表现出明显的各向异性且应变率对力学性能与微观组织有一定的影响。相同应变率下,0°方向上的应力最大,45°方向上的应力最小。在0°方向上,合金的抗拉强度随应变率的增加变化相对较小,而屈服强度、延伸率和断面收缩率呈现先增加后保持不变最后持续增加的趋势;在45°和90°方向上,合金的抗拉强度、屈服强度、延伸率与断面收缩率均随着应变率的提高呈现先增加后保持不变最后持续增加的趋势;90°方向相比于其他两个方向有着更强的应变率敏感性。拟合得到三个方向上的Johnson-Cook本构方程,其可以很好地预测2024-T351铝合金在各个方向上的动态力学行为。所有试样断口表面均有大小不一的韧窝,且应变率越高形成的韧窝就会越大且越深。断后晶粒尺寸与方向和应变率基本无关,但晶粒纵横比受方向和应变率的影响较大。

关键词：铝合金动态力学行为各向异性微观组织 Johnson-Cook本构模型

《化工环境保护与安全生产》课程教学探索与改革

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当代化工研究 2024年第3期 129-131页

作者：许振民刘吉波毛海舫上海应用技术大学上海201418

《化工环境保护与安全生产》课程作为化工专业人才培养中的核心教材,是实施专业课程改革的重要载体。本文针对目前《化工环境保护与安全技术》课程教学过程中普遍存在的问题,深度探索了课程改革的措施与实践的意义。并结合高水平教师队... 详细信息

《化工环境保护与安全生产》课程作为化工专业人才培养中的核心教材,是实施专业课程改革的重要载体。本文针对目前《化工环境保护与安全技术》课程教学过程中普遍存在的问题,深度探索了课程改革的措施与实践的意义。并结合高水平教师队伍、案例式教学方案、工作式教学实践,以及多元化考核模式,将多样化知识元素融入教学,使专业知识与思想教育有机统一,从而实现培养有潜力、可持续发展的化工高素质复合型化工人才的目标。

关键词：化工环境保护与安全生产教学探索课程改革

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8万t/a戊烷工艺换热网络优化设计

应用技术学报 2024年第2期24卷 160-166页

作者：李鹏飞刘吉波章平毅毛海舫靳苗苗上海应用技术大学化学与环境工程学院上海201418

针对80 000 t/a戊烷工艺,采用Aspen Plus软件对生产工艺能耗进行分析。采用热泵精馏对工艺流程进行节能设计,并进一步利用夹点技术对换热网络进行集成和优化。优化结果表明:优化后换热网络共回收热量8 509 kW,热公用工程节省54.9%,冷公... 详细信息

针对80 000 t/a戊烷工艺,采用Aspen Plus软件对生产工艺能耗进行分析。采用热泵精馏对工艺流程进行节能设计,并进一步利用夹点技术对换热网络进行集成和优化。优化结果表明:优化后换热网络共回收热量8 509 kW,热公用工程节省54.9%,冷公用工程节省70.6%。同时减少了约67.5%的工艺换热面积,优化后总费用下降约35.2%。

关键词：戊烷工艺换热网络热泵精馏

Joint UAV trajectory and communication design with heterogeneous multi-agent reinforcement learning

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Science China(Information Sciences) 2024年第3期67卷 225-245页

作者： Xuanhan ZHOU Jun XIONG Haitao ZHAO Xiaoran liu Baoquan REN Xiaochen ZHANG jibo WEI Hao YIN College of Electronic Science and Technology National University of Defense Technology Systems Engineering Institute Academy of Military Sciences PLA

Unmanned aerial vehicles(UAVs) are recognized as effective means for delivering emergency communication services when terrestrial infrastructures are unavailable. This paper investigates a multiUAV-assisted communication system, where we jointly optimize UAVs’ trajectories, user association, and ground users(GUs)’ transmit power to maximize a defined fairness-weighted throughput metric. Owing to the dynamic nature of UAVs, this problem has to be solved in real time. However, the problem’s non-convex and combinatorial attributes pose challenges for conventional optimization-based algorithms, particularly in scenarios without central controllers. To address this issue, we propose a multi-agent deep reinforcement learning(MADRL) approach to provide distributed and online solutions. In contrast to previous MADRLbased methods considering only UAV agents, we model UAVs and GUs as heterogeneous agents sharing a common objective. Specifically, UAVs are tasked with optimizing their trajectories, while GUs are responsible for selecting a UAV for association and determining a transmit power level. To learn policies for these heterogeneous agents, we design a heterogeneous coordinated QMIX(HC-QMIX) algorithm to train local Q-networks in a centralized manner. With these well-trained local Q-networks, UAVs and GUs can make individual decisions based on their local observations. Extensive simulation results demonstrate that the proposed algorithm outperforms state-of-the-art benchmarks in terms of total throughput and system fairness.

关键词： unmanned aerial vehicle (UAV) trajectory design resource allocation multi-agent deep reinforcement learning (MADRL) heterogeneous agents

Bionic Hand Motion Control Method Based on Imitation of Human Hand Movements and Reinforcement Learning

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Journal of Bionic Engineering 2024年第2期21卷 764-777页

作者： jibo Bai Baojiang Li Xichao Wang Haiyan Wang Yuting Guo The School of Electrical Engineering Shanghai DianJi UniversityShanghai201306China

Bionic hands are promising devices for assisting individuals with hand disabilities in rehabilitation *** primarily by bioelectrical signals such as myoelectricity and EEG,these hands can compensate for lost hand ***,developing model-based controllers for bionic hands is challenging and time-consuming due to varying control parameters and unknown application *** address these challenges,we propose a model-free approach using reinforcement learning(RL)for designing bionic hand *** method involves mimicking real human hand motion with the bionic hand and employing a human hand motion decomposition technique to learn complex motions from simpler *** approach significantly reduces the training time *** utilizing real human hand motion data,we design a multidimensional sampling proximal policy optimization(PPO)algorithm that enables efficient motion control of the bionic *** validate the effectiveness of our approach,we compare it against advanced baseline *** results demonstrate the quick learning capabilities and high control success rate of our method.

关键词： Bionic hand Reinforcement learning Motion decomposition Multidimensional sampling PPO algorithm

Microstructure Evolution,Tribological and Corrosion Properties of Amorphous Alloy Strengthening Stainless Steel Fabricated by Selective Laser Melting in NaCl Solution

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Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 825-839页

作者： Pengwei Jiang Gang Wang Yaosha Wu Zhigang Zheng Zhaoguo Qiu Tongchun Kuang jibo Huang Dechang Zeng School of Materials Science and Engineering South China University of TechnologyGuangzhou 510640China Zhongshan R&D Center for Materials Surface and Thin Films Technology of the South China University of Technology Gent Materials Surface Technology(Guangdong)Co.Ltd.Zhongshan 528437China Zhongshan Torch Polytechnic Zhongshan 528436China Yangjiang Branch Guangdong Laboratory Materials Science and Technology Yangjiang Advanced Alloys LaboratoryYangjiang 529599China

As a type of austenitic stainless steel,316L stainless steel has excellent plasticity,corrosion resistance,and biocompatibility,making it widely used in industries,especially in the marine ***,its lower yield strength and wear resistance are the obvious disadvantages that restrict its application in more *** this work,an Fe-based amorphous alloy(Fe^(am))was selected as reinforcement to enhance the 316L stainless steel prepared by selective laser melting(SLM),and microstructure evolution,mechanical properties,tribological and corrosion performance of the SLMed samples were investigated in *** relative density values of both 316L stainless steel and Fe^(am)-reinforced samples are above 99%,which suggests that Fe^(am)-reinforced samples also have outstanding *** the as-etched micrograph,all of the SLMed samples exhibit cellular ***^(am)-reinforced samples have thicker sub-grain boundaries,and retained amorphous phase can be observed in the samples reinforced with 10 wt%and 15 wt%Fe^(am).As the addition of Fe^(am) increases,the microhardness and compression strength of the Fe^(am)-reinforced samples gradually improve and reach 449.2 HV and 2181.9 MPa,*** wear morphologies show that the 316L stainless steel and Fe^(am)-reinforced samples both experience abrasive wear and corrosion wear in a 3.5 wt%NaCl ***,as the amount of Fe^(am) added increases,the coefficient of friction and wear rate of SLMed samples gradually *** to the unreinforced sample,Fe^(am)-reinforced samples have lower corrosion current density and higher pitting potential according to the potentiodynamic polarization curves and also exhibit superior corrosion resistance in the salt spray *** work suggests that the addition of Fe-based amorphous alloy can improve the mechanical properties and wear resistance of 316L stainless steel,as well as its ability to withstand salt spray corrosion.

关键词： Selective laser melting 316L stainless steel Amorphous alloy Tribology Corrosion

Putrescine Modulates Cadmium Fixation Ability of Cell Wall to Decrease Cadmium Accumulation in Rice,a Process Might Depend on Nitric Oxide

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Rice science 2024年第3期31卷 237-240,I0002-I0007页

作者： WANG Haoyu LI Su YANG jibo HUANG Jing ZHU Xiaofang SHEN Renfang ZENG Dali College of Advanced Agricultural Sciences Zhejiang A&F UniversityHangzhou 311300China State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of ScienceNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China

Although putrescine(PUT)has been linked to plants'responses to cadmium(Cd)stress,the exact mechanism is still *** the current investigation,the endogenous PUT concentration in rice roots was enhanced by Cd *** PUT increased root cell wall hemicellulose levels,which in turn increased its Cd binding capacity,concurrently decreasing the transcription level of genes such as OsNRAMP1 and OsCd1 that are responsible for root Cd *** a result。

关键词： absorption roots cadmium

Entropy consistency-based adaptive sampling method for determining the scale effect in the joint roughness coefficient

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Journal of Earth Science 2024年

作者： jibo Qin Jun Ye Xiaoming Sun Shigui Du State Key Laboratory for Tunnel Engineering China University of Mining and Technology-Beijing School of Mechanics and Civil Engineering China University of Mining and Technology-Beijing Institute of Rock Mechanics Ningbo University

The joint roughness coefficient （JRC） is one of the key parameters for evaluating the shear strength of rock joints. Because of the scale effect in the JRC， reliable JRC values are of great importance for most rock engineering projects. During the collection process of JRC samples， the redundancy or insufficiency of representative rock joint surface topography （RJST） information in serial length JRC samples is the essential reason that affects the reliability of the scale effect results. Therefore， this paper proposes an adaptive sampling method， in which we use the entropy consistency measure Q（a） to evaluate the consistency of the joint morphology information contained in adjacent JRC samples. Then the sampling interval is automatically adjusted according to the threshold Q(at) of the entropy consistency measure to ensure that the degree of change of RJST information between JRC samples is the same， and ultimately makes the representative RJST information in the collected JRC samples more balanced. The application results of actual cases show that the proposed method can obtain the scale effect in the JRC efficiently and reliably.

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热处理对超音速火焰喷涂增材制造9Cr18Ni12/WC10Co4Cr流道微观结构和空蚀性能的影响

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稀有金属 2023年第5期47卷 778-786页

作者：方凯王晓霞王欣刘吉波刘光所新坤宁波大学机械工程与力学学院浙江宁波315211 中国兵器科学研究院宁波分院浙江宁波315103 宁波大学阳明学院浙江宁波315211 宁波展慈新材料科技有限公司浙江宁波315334

超音速火焰喷涂(HVOF)能够制备金属陶瓷复合涂层,是一种潜在的增材制造技术(AM)技术。以9Cr18Ni12和WC10Co4Cr粉末为原材料,采用HVOF制备9Cr18Ni12/WC10Co4Cr金属基复合材料流道,通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)、显微硬度... 详细信息

超音速火焰喷涂(HVOF)能够制备金属陶瓷复合涂层,是一种潜在的增材制造技术(AM)技术。以9Cr18Ni12和WC10Co4Cr粉末为原材料,采用HVOF制备9Cr18Ni12/WC10Co4Cr金属基复合材料流道,通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)、显微硬度仪及超声波空蚀试验等方法分析了热处理对金属基复合材料流道的相成分、微观组织结构、硬度及耐空蚀性能的影响。结果表明,流道的平均孔隙率为1.34%,经热处理后升高至3.40%。在热处理后复合材料流道的相组成与喷涂态相比没有出现新相,内部颗粒边界由于热处理发生了边界熔合现象。复合材料流道的显微硬度为HV0.3(394.8±47.3),该值随热处理温度变化幅度较小。在进行热处理之后,复合材料流道在空蚀试验中的质量累积损失从(6.2±0.08) mg下降到(3.6±0.06) mg,表明热处理显著提高了金属基复合材料流道的耐空蚀性能。该研究为探索一种新的金属基复合材料AM技术提供了基础实验数据。

关键词：超音速火焰喷涂(HVOF) 增材制造(AM) 流道热处理微观结构空蚀