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Crashworthiness Optimization of Steel-Magnesium Hybrid Double-Hat-Shaped Tubes

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Automotive Innovation 2018年第3期1卷 247-254页

作者： guojun zheng Zhiyuan Fan Hui Zhang Ping Zhou School of Automotive Engineering Dalian University of TechnologyDalian 116024China German Aerospace Centre(DLR)-Institute of Vehicle Concepts Pfaffenwaldring 38-4070569 StuttgartGermany

The double-hat-shaped magnesium tube was difficult to use in actual applications due to its frangible material property.Magnesium alloy and traditional steel were integrated into a new hybrid thin-walled double-hat-shaped tube to improve vehicle crashworthiness.Two classes of hybrid tubes were examined,namely Hybrid-I(steel top hat and magnesium alloy bottom hat)and Hybrid-II(magnesium alloy top hat and steel bottom hat).The energy absorption characteristics and crashworthiness optimization of the thin-walled hybrid structures were investigated under three-point bending conditions through experiments and simulations.Multi-objective optimization design for the two hybrid tubes was implemented to elucidate their lightweight properties.Results showed that the specific energy absorption of Hybrid-I tube and Hybrid-II tube was approximately 44.7%and 12.7%higher than that of the double-hat-shaped DC04 tube,respectively.The Hybrid-I tube had better crashworthiness and lightweight properties compared with Hybrid-II tube.Hybrid-I tube also had better lightweight properties than single-material steel tube and reduced wall thickness compared with magnesium alloy tube.

关键词： Lightweight design Magnesium alloy Hybrid double-hat-shaped tube Crashworthiness Steel

新型肠炎沙门菌菌影候选疫苗在小鼠免疫应答和保护功效的评估

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中华微生物学和免疫学杂志 2024年第4期44卷 295-303页

作者：杨慧韩雪杜小春焦红梅郑国军常州市第三人民医院检验科常州213000 扬州大学医学院/转化医学研究院病原生物学教研室扬州225001

目的比较肠炎沙门菌制备的菌影(SE-ghost)通过肌肉注射(肌注)和口服不同免疫途径接种雌性BALB/c小鼠诱导体液和细胞免疫应答的功效。方法用SE-ghost接种BALB/c小鼠,间接ELISA检测小鼠血清中IgG抗体水平和阴道灌洗液IgA抗体水平;流式细... 详细信息

目的比较肠炎沙门菌制备的菌影(SE-ghost)通过肌肉注射(肌注)和口服不同免疫途径接种雌性BALB/c小鼠诱导体液和细胞免疫应答的功效。方法用SE-ghost接种BALB/c小鼠,间接ELISA检测小鼠血清中IgG抗体水平和阴道灌洗液IgA抗体水平;流式细胞仪检测小鼠脾脏CD3^(+)CD4^(+)T、CD3^(+)CD8^(+)T细胞百分比变化和脾脏内细胞因子IL-4、IFN-γ分泌;三次免疫后所有小鼠口服半数致死量肠炎沙门菌进行强毒攻击。用SE-ghost刺激小鼠骨髓来源树突状细胞(BMDCs),流式细胞仪检测表面分子抗体APC-CD11c、FITC-MHC ClassⅡ、PE-CD40、FITC-CD86、PE-CD80表达量;双抗体夹心ELISA测定BMDCs上清液IL-1β、IL-6、IL-10和IL-12p70的产量。结果与PBS组相比,SE-ghost(口服)和SE-ghost(肌注)免疫组小鼠体内肠炎沙门菌特异性抗体IgG和IgA水平明显增高;脾脏CD3^(+)CD4^(+)T细胞百分比上调、高分泌细胞因子IL-4、IFN-γ。肌肉注射SE-ghost比口服可诱导更强的体液和细胞免疫应答。致病菌肠炎沙门菌强毒攻击后,SE-ghost(口服)和SE-ghost(肌注)免疫组生存率高达80%。与对照组相比,BMDCs经SE-ghost刺激后高表达表面成熟分子抗体CD86、CD80、CD40、MHCⅡ,高分泌细胞因子IL-1β、IL-6、IL-10、IL-12p70。结论通过肌肉注射SE-ghost进行免疫,可在小鼠中引发更强大的抗原特异性免疫应答,以防止沙门菌感染。SE-ghost是一种有用的沙门菌候选疫苗。

关键词：肠炎沙门菌细菌菌影灭活疫苗免疫应答保护功效

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基于混合遗传算法的多无人机巡逻路径优化

浙江大学学报（理学版） 2024年第1期51卷 21-28页

作者：李国军郑滋椀范英盛卢甜甜徐志江浙江警察学院公共基础部浙江杭州310053 浙江警察学院大数据与网络安全研究院浙江杭州310053 浙江机电职业学院自动化学院浙江杭州310053

假设无人机巡逻的起、终点均为派出所,提出了一种融合传统遗传算法和爬山算法的警用无人机巡逻路径优化模型——混合遗传算法。按照轮盘赌法则,进行种群个体的选择,以增大优秀种群个体被选中的概率,达到较好的优化效果。同时定义了与路... 详细信息

假设无人机巡逻的起、终点均为派出所,提出了一种融合传统遗传算法和爬山算法的警用无人机巡逻路径优化模型——混合遗传算法。按照轮盘赌法则,进行种群个体的选择,以增大优秀种群个体被选中的概率,达到较好的优化效果。同时定义了与路径优化相适应的基因交叉和变异规则。仿真结果表明,提出的混合遗传算法在寻优效果上明显优于传统遗传算法。

关键词：遗传算法爬山算法巡逻路径优化

Wind tunnel investigation of different engine layouts of a blended-wing-body transport

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中国航空学报:英文版 2023年第9期36卷 123-132页

作者： zheng CUI guojun LAI Qifeng WANG Yu LIANG Yihua CAO School of Aeronautic Science and Engineering Beihang UniversityBeijing 100083China COMAC Beijing Aircraft Technology Research Institute Beijing 102211China

A 2%scale,cruising version of a 450-seat class Blended-Wing-Body(BWB)transport was tested in the China Aerodynamic Research and Development Center’s FL-262.4-by-2.4-meter subsonic wind tunnel.The focus of the wind tunnel test was to investigate the aerodynamic performance of the latest BWB transport design,which would also aid in choosing a final engine arrangement in the three most potential engine integration layouts.The wind tunnel model can be tested with and without the nacelle and has three sets of different nacelle/tail integration positions.Computational Fluid Dynamics(CFD)simulations were performed in engine-aircraft integration design to find appropriate nacelle installing parameters of each layout.The comparison of CFD with experimental results shows good agreement.Wind tunnel measurements indicate that the tail-mounted engine layout produces the minimum drag penalty,while the fuselage-mounted engine layout increases drag the most.Experimental pressure measurement illustrates the effect of nacelle integration on the wing-body surface pressure distribution.This experimental and numerical research provides a reference for future BWB Propulsion-Airframe Integration(PAI)design.

关键词： PAI Aerodynamics BWB CFD Civil aviation Engine layout Transport aircraft Wind tunnels

Hierarchical Ni-plated melamine sponge and MXene film synergistically supported phase change materials towards integrated shape stability,thermal management and electromagnetic interference shielding

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Journal of Materials Science & Technology 2023年第1期132卷 132-143页

作者： Ziling Cheng guojun Chang Bai Xue Lan Xie Qiang zheng State Key Laboratory of Public Big Data Guizhou UniversityGuiyang 550025China Department of Polymer Materials and Engineering College of Materials and MetallurgyGuizhou UniversityGuiyang 550025China National Engineering Research Center for Compounding and Modification of Polymer Materials National and Local Joint Engineering Research Center for Functional Polymer Membrane Materials and Membrane ProcessesGuiyang 550014China College of Polymer Science and Engineering Zhejiang UniversityHangzhou 310000China

Along with the integrated and miniaturized development of advanced electronic devices,phase change materials(PCMs)simultaneously with efficient thermal management and high electromag-netic interference(EMI)shielding effectiveness(SE)are ungently demanded.Herein,the shape-stabilized MXene/Ni-platted melamine sponge/Regenerated cellulose/Graphene nanoplate/Polyethylene glycol(MX/Ni@MS/RCG/PEG)composite PCMs comprising hierarchical Ni@MS/RCG and MXene film were fabricated via a facile encapsulation approach.Hierarchical Ni@MS/RCG hybrid aerogel was prepared by electroless plating and sol-gel methods,and MXene film was obtained using vacuum-assisted filtra-tion procedure.The synergistic effect of conductive Ni@MS/RCG networks and tight MXene film endows MX/Ni@MS/RCG/PEG composite PCMs with good shape stability,high cyclic reliability,large latent heat of phase change(154.3 J g^(–1)),excellent thermal conductivity(TC,0.47 W m^(–1)K^(–1))and favorable EMI shield-ing performance(32.7 dB).The TC of acceptable 0.47 W m^(–1)K^(–1)is observed for MX/Ni@MS/RCG-5/PEG at a rather low GNP content of merely 0.39 wt%.In addition,the temperature variation of MX/Ni@MS/RCG-5/PEG is a lot faster than that of pure PEG in the heating/cooling process,revealing the remarkable energy storage and release efficiency for the composite PCMs.This investigation has taken an important step to-wards shape-stabilized composite PCMs with both effective thermal management and high EMI SE for promising applications in electronic packaging and advanced energy.

关键词： Phase change material Thermal management Electromagnetic interference shielding Shape stability Encapsulation

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基于样本嵌入的挖矿恶意软件检测方法

计算机科学 2024年第1期51卷 327-334页

作者：傅建明姜宇谦何佳郑锐苏日古嘎彭国军武汉大学国家网络安全学院空天信息安全与可信计算教育部重点实验室武汉430072 嵩山实验室技术中心郑州450046 河南大学计算机与信息工程学院河南开封475000

加密货币挖矿恶意软件的高盈利性和匿名性,对计算机用户造成了巨大威胁和损失。为了对抗挖矿恶意软件带来的威胁,基于软件静态特征的机器学习检测器通常选取单一类型的静态特征,或者通过集成学习来融合不同种类静态特征的检测结果,忽略... 详细信息

加密货币挖矿恶意软件的高盈利性和匿名性,对计算机用户造成了巨大威胁和损失。为了对抗挖矿恶意软件带来的威胁,基于软件静态特征的机器学习检测器通常选取单一类型的静态特征,或者通过集成学习来融合不同种类静态特征的检测结果,忽略了不同种类静态特征之间的内在联系,其检测率有待提升。文章从挖矿恶意软件的内在层级联系出发,自下而上提取样本的基本块、控制流程图和函数调用图作为静态特征,训练三层模型以将这些特征分别嵌入向量化,并逐渐汇集从底层到高层的特征,最终输入分类器实现对挖矿恶意软件的检测。为了模拟真实环境中的检测情形,先在一个小的实验数据集上训练模型,再在另一个更大的数据集上测试模型的性能。实验结果表明,三层嵌入模型在挖矿恶意软件检测上的性能领先于近年提出的机器学习模型,在召回率和准确率上相比其他模型分别提高了7%和3%以上。

关键词：挖矿恶意软件静态分析机器学习图嵌入

近七十年(1954–2021)长江中下游湖泊沉水植物群落多样性演变特征

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生物多样性 2024年第3期32卷 33-47页

作者：陈瑶琪郭晶晶蔡国俊葛依立廖宇董正符辉湖南农业大学环境与生态学院洞庭湖区农村生态系统健康湖南省重点实验室长沙410128 始兴中学广东韶关512599

沉水植物在维持浅水湖泊生态系统健康和稳定等方面起着重要作用,掌握其长期动态及驱动因子对湖泊生态系统恢复和富营养化治理具有重要的理论和现实意义。本研究以长江中下游17个湖泊为研究对象,分析了近70年(1954–2021)来沉水植物的α... 详细信息

沉水植物在维持浅水湖泊生态系统健康和稳定等方面起着重要作用,掌握其长期动态及驱动因子对湖泊生态系统恢复和富营养化治理具有重要的理论和现实意义。本研究以长江中下游17个湖泊为研究对象,分析了近70年(1954–2021)来沉水植物的α和β多样性格局及其变化情况,并基于Sørensen相异性指数将β多样性分解为周转(turnover)和嵌套(nestedness)两个组分,探讨了湖泊环境异质性变化与沉水植物群落多样性格局的联系。结果表明:(1)在湖泊尺度上,11个湖泊沉水植物的α多样性呈减小趋势;而大多数湖泊β_(temporal)多样性(同一湖泊不同年份之间的群落结构相异性)无显著变化,且其变异主要由不同物种间的嵌套成分驱动。(2)在流域尺度上,长江中下游湖泊沉水植物的α多样性在演化过程中呈先增大后减小的趋势,β_(spatial)多样性(同一时期不同湖泊之间的群落结构相异性)在演化过程中呈逐渐减小的趋势,而湖泊环境异质性呈逐渐增大的趋势。(3)环境异质性越高的湖泊,其α多样性越小,β多样性越大。这些变化可能是多种因素综合作用的结果,包括人类活动、水质污染、水文变化和气候变化等。本研究对于长江中下游湖泊生态系统管理和保护具有一定理论价值,为制定有效的保护策略和措施提供了科学依据。

关键词：沉水植物湖泊 α多样性 β多样性群落演替环境异质性

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钢液真空处理过程中Mn挥发动力学研究

武汉科技大学学报 2024年第2期47卷 81-86页

作者：何瑞翔张翔马国军陈子宏郑顶立杜天雨武汉科技大学钢铁冶金及资源利用省部共建教育部重点实验室湖北武汉430081 武汉科技大学钢铁冶金新工艺湖北省重点实验室湖北武汉430081 上海鑫蓝海自动化科技有限公司上海201203

Mn作为提高钢材强度的主要元素之一,在钢液真空处理过程中的挥发会对钢材成分及质量控制产生不利影响,因此,明确钢液中Mn的挥发机理,并据此精确调控钢液中Mn含量,对于保证钢材质量显得尤为重要。本研究针对X80管线钢的真空精炼处理过程... 详细信息

Mn作为提高钢材强度的主要元素之一,在钢液真空处理过程中的挥发会对钢材成分及质量控制产生不利影响,因此,明确钢液中Mn的挥发机理,并据此精确调控钢液中Mn含量,对于保证钢材质量显得尤为重要。本研究针对X80管线钢的真空精炼处理过程,分析了气相压强和熔炼温度对钢液中Mn挥发行为的影响。结果表明:随着熔炼温度的升高和气相压强的降低,钢液中Mn挥发速率明显加快;在熔炼温度1903 K、气相压强19 Pa、处理时间40 min条件下,Mn挥发率高达92.26%。在熔炼温度1823~1973 K、气相压强19~670 Pa条件下,Mn挥发遵循一级反应规律,其表观挥发速率常数在(0.41~26.56)×10^(-5)m/s范围内;在气相压强19~670 Pa、熔炼温度1903 K的条件下,Mn挥发主要受气相传质的限制;在气相压强226 Pa、熔炼温度1823~1973 K的条件下,Mn挥发的表观活化能达到120.20 kJ/mol,限制性环节为气-液界面反应;本研究条件下,液相传质对Mn挥发速率的影响较小。

关键词：真空处理钢液 Mn 挥发熔炼温度气相压强传质系数动力学

Effect of functional groups on tribological properties of lubricants and mechanism investigation

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Friction 2023年第6期11卷 911-926页

作者： Hongxiang YU Haijie CHEN Zhiwen zheng Dan QIAO Dapeng FENG Zhenbin GONG guojun DONG State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing100049China

Nine organic compounds were utilized as model lubricants to investigate the impact of functional groups on tribological performances.Nonanoic Acid with carboxyl showed the best lubrication properties,and fluid film and tribofilm were coexistent in its friction test,bringing a low friction coefficient and wear rate.In addition,the lubricant with low friction coefficient corresponded to high adsorption energy in density functional theory(DFT)calculations.And the lubricant forming adsorption film with large surface energy displayed small wear rate in friction test.Moreover,adsorption energies positively correlated surface energies.Based on the experimental results,the action mechanism of functional groups on tribological properties of lubricants was proposed.Various functional groups make lubricant molecules show different adsorption energies and surface energies.Lubricant molecules with high adsorption energy are more likely to adsorb on substrates and form a vertical monolayer,which can maintain a regular molecular brush structure during friction and bring a low friction coefficient.And lubricant molecules with high surface energy may be more prone having tribochemical reactions during friction and forming protective tribofilm,which leads to a low wear rate.

关键词： functional group tribological property adsorption energy surface energy action mechanism