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Effect of melt holding on morphological evolution and sedimentation behavior of iron-rich intermetallic phases in Al-Si-Fe-Mn-Mg alloy

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Transactions of Nonferrous Metals Society of China 2020年第1期30卷 1-13页

作者： Dong-fu song Shun-cheng WANG Yu-liang ZHAO Shu-hong LIU Yong DU Yue-hua KANG Zhi WANG Wei-wen ZHANG National Engineering Research Centre of Near-net-shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510641China Guangdong Institute of Materials and Processing Guangzhou 510650China School of Mechanical Engineering Dongguan University of TechnologyDongguan 523808China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China

The effect of the melt holding temperature on the morphological evolution and sedimentation behavior of iron-rich intermetallics in Al-7.0 Si-1.0 Fe-1.2 Mn-0.25 Mg alloy was investigated using an optical microscope,scanning electron microscope and differential thermal *** results show that as the holding temperature decreases,the morphologies of the primary iron-rich phase in matrix change from star-like to polygonal,and the number of the primary phases gradually decreases and disappears at 615°***,the Chinese script phases with small size,high compact and uniform distribution are *** contrast,the primary iron-rich phases in slag transform into a coarser polygonal shape with lower roundness,and some of them have hollow ***,the area fraction of intermetallics and Fe content in the matrix decrease gradually due to the formation and growth of sludge and subsequent natural sedimentation during melt *** the decrease of holding temperature,the main factors hindering the settlement of the primary phases are morphology,size,and density in turn.

关键词： Al-Si alloy melt holding iron-rich intermetallic phases morphological evolution sedimentation behaviour

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一种液压驱动机械臂多关节力矩控制方法

计算机仿真 2022年第7期39卷 391-395页

作者：史洪松敖昕江西工程学院智能制造与能源工程学院江西新余338000 深圳大学微纳光电子学研究院广东深圳518060

采用目前方法控制液压驱动机械臂的关节力矩时,没有对液压驱动机械臂的运动学和动力学进行分析,导致方法存在关节位置跟踪误差大、控制效率低、控制性能差和压力损失大的问题。提出液压驱动机械臂多关节力矩控制方法,分析了液压驱动机... 详细信息

采用目前方法控制液压驱动机械臂的关节力矩时,没有对液压驱动机械臂的运动学和动力学进行分析,导致方法存在关节位置跟踪误差大、控制效率低、控制性能差和压力损失大的问题。提出液压驱动机械臂多关节力矩控制方法,分析了液压驱动机械臂的结构,并建立了机械臂坐标,分析液压驱动机械臂关节在坐标系中的运动情况,在Lagrange函数的基础上建立其动力学模型,分析关节在液压驱动机械臂运动过程中的势能和动能。对机械臂关节力矩误差和误差变化率进行计算,并将其作为模糊神经网络的输入变量,通过模糊神经网络完成液压驱动机械臂多关节力矩的控制。仿真结果表明,所提方法的关节位置跟踪误差小、控制效率高、控制性能好、压力损失小。

关键词：液压驱动机械臂关节力矩动力学模型模糊神经网络力矩控制

基于多重多级动力子结构的Lanczos算法

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振动与冲击 2012年第6期31卷 23-26,47页

作者：张盛方杰张洪武陈飙松大连理工大学工业装备结构分析国家重点实验室大连116024 大连理工大学运载工程与力学学部工程力学系大连116024

提出利用多重多级子结构技术与Lanczos方法求解超大型复杂结构动力特性的子结构算法。该算法利用子结构周游树技术,分别对每个子结构进行Lanczos迭代,通过累加各个子结构的正交化系数组成全局三对角矩阵,最后求解得到整体结构的特征值... 详细信息

提出利用多重多级子结构技术与Lanczos方法求解超大型复杂结构动力特性的子结构算法。该算法利用子结构周游树技术,分别对每个子结构进行Lanczos迭代,通过累加各个子结构的正交化系数组成全局三对角矩阵,最后求解得到整体结构的特征值。算法能够计算超大型结构特征值和特征向量,计算效率高;消耗计算机资源少,稳定性高。由于考虑了各子结构内部自由度对整体求解的贡献,算法精度得到显著提高,并与不作凝聚的单一整体结构分析具有相同的计算精度,计算结果不受复杂子结构划分方式的限制。数值算例验证了所提出算法的正确与有效性。

关键词：多重多级子结构子结构树周游 Lanczos方法特征值特征向量

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埃及渔业现状、问题及建议

中国渔业经济 2010年第3期28卷 71-75页

作者：方松赵红萍中国水产科学研究院

2009年9～12月,笔者赴埃及参加了由埃及农业国际培训中心举办的"Fish Culture Development"培训。结合资料查询以及学习体会,笔者从水产养殖、资源捕捞、水产品加工、水产品市场以及水产宏观管理等五方面介绍了埃及渔业发展现状,分析了... 详细信息

2009年9～12月,笔者赴埃及参加了由埃及农业国际培训中心举办的"Fish Culture Development"培训。结合资料查询以及学习体会,笔者从水产养殖、资源捕捞、水产品加工、水产品市场以及水产宏观管理等五方面介绍了埃及渔业发展现状,分析了存在的不足,并从加快发展水产养殖业,控制资源捕捞强度、延长产业链以及加强科技基础研究等四方面提出了建议。

关键词：水产养殖资源捕捞科技研究

A large-scale fatal outbreak of Pasteurella multocida among wild rodents in southwestern China

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Journal of Biosafety and Biosecurity 2020年第2期2卷 91-98页

作者： Chun-hong Du Yong Huang Jia-Fu Jiang Zi-Hou Gao Na Jia Shan Yang Chao-Nian Chen Shun-Gao Ma Yu-Ying Liang Bao-Gui Jiang Wei-hong Sang Peng Wang Yun Liang Yun-Zhi Zhang Ji-Hua Zhou Shui-Ping Chen Frans Jongejan Zhi-Zhong song Yi-Gang Tong Wu-Chun Cao State Key Laboratory of Pathogen and Biosecurity Beijing Institute of Microbiology and EpidemiologyBeijingPR China Yunnan Institute for Endemic Diseases Control and Prevention Dali YunnanPR China Puer Center for Disease Control and Prevention PuerYunnanPR China Simao Prefecture Center for Disease Control and Prevention PuerYunnanPR China DaLi Bai Autonomous Prefecture People’Hospital YunnanPR China Fifth Medical Center of PLA General Hospital BeijingPR China Utrecht Centre for Tick-borne Diseases(UCTD) Faculty of Veterinary MedicineUtrecht UniversityYalelaan 13584 CL UtrechtThe Netherlands College of Life Science and Technology Beijing University of Chemical Technology.BeijingPR China

Background:Pasteurella multocida is an important and old zoonotic pathogen worldwide which has an impressive host spectrum including numerous domestic and wild animals as well as birds,causing specific diseases or outbreak with great economic *** has never been reported that *** can cause an epidemic in wild *** June 5–17,2016,more than 1000 rodent deaths of an unknown cause quickly spread in the PuEr City,Yunnan province,southwestern ***:The rodents in affected areas and outside of the epidemic areas were collected and screened for possible known pathogens including Yersinia pestis,rabies virus and hantavirus as well as other *** possible bacterial pathogens were isolated both by culture medium and by mouse inoculation in *** isolates were identified by the Vitek GNI card and PCR assays for 16S rRNA *** pathogen strains were selected for whole genome sequencing ***:A total of 123 rodents were collected from 25 sample sites at affected area,among of which,all 119 dead rodents were negative for the pathogen under consideration except ***,and all four live rodents were negative for *** addition,480 rodents collected from other 23 counties outside of the epidemic area in Yunnan were negative for with ***.A total of 14 strains of ***(six directly isolated from the field rodents and eight from the experimental mice that were injected with the organ substrates from the dead rodents)belonged to serogroup A and serogroup F represented by 9 N and 20 N were identified in these epidemic *** genome sequencing revealed that the serogroup F strain shared 99%similarity to *** Pm70 from chicken,but contained a 50 k bp insertion *** serogroup A strain shared 95%similarity to *** FDAARGOS_385 from a human patient,but contained four large structural *** abnormalities were identified in the livers,lungs,hearts and brains of the ino

关键词： Pasteurella multocida Serotypes A Serotypes F Rodents Outbreak China

Slightly ruthenium doping enables better alloy nanoparticle exsolution of perovskite anode for high-performance direct-ammonia solid oxide fuel cells

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Journal of Materials Science & Technology 2022年第30期125卷 51-58页

作者： Xiandong Xiong Jian Yu Xiaojian Huang Dan Zou Yufei song Meigui Xu Ran Ran Wei Wang Wei Zhou Zongping Shao State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 210009China Department of Mechanical and Aerospace Engineering The Hong Kong University of Science and TechnologyClear Water BayHong KongChina WA School of Mines:Minerals Energy and Chemical Engineering(WASM-MECE)Curtin UniversityPerthWA 6845Australia

Fuel flexibility is one of the most distinguished advantages of solid oxide fuel cells(SOFCs)over other low-temperature fuel ***,the combination of ammonia fuel and SOFCs technology should be a promising clean energy system after considering the high energy density,easy transportation/storage,matured synthesis technology and carbon-free nature of NH_(3) as well as high efficiency of ***,the large-scale applications of direct-ammonia SOFCs(DASOFCs)are strongly limited by the inferior anti-sintering capability and catalytic activity for ammonia decomposition reaction of conventional nickel-based cermet ***,a slightly ruthenium(ru)doping in perovskite oxides is proposed to promote the alloy nanoparticle exsolution,enabling better DA-SOFCs with enhanced power outputs and operational *** treating ru-doped Pr_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.75)ru_(0.05)O_(3-δ) single-phase perovskite in a reducing atmosphere,in addition to the formation of two layered ruddlesden-Popper perovskites and Pr_(2)O_(3) nanoparticles(the same as the ru-free counterpart,Pr_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)),the exsolution of CoFeru-based alloy nanoparticles is remarkably *** reduced Pr_(0.6)Sr0.4Co_(0.2)Fe_(0.75)ru_(0.05)O_(3-δ) composite anode shows superior catalytic activity and stability for NH_(3) decomposition reaction as well as anti-sintering capability in DA-SOFCs to those of reduced Pr0.6Sr0.4Co0.2Fe0.8O_(3-δ)due to the facilitated nanoparticle exsolution and stronger nanoparticle/substrate *** work provides a facile and effective strategy to design highly active and durable anodes for DA-SOFCs,promoting large-scale applications of this technology.

关键词： Solid oxide fuel cell Ammonia Exsolution Perovskite anode ruthenium doping

异丙醇-水萃取精馏的复合溶剂选择和实验研究

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高校化学工程学报 2008年第3期22卷 407-411页

作者：张颂红姚克俭姚笛曾妮浙江工业大学化学工程与材料学院绿色合成技术国家重点实验室培育基地浙江杭州310032

通过UNIFAC方程选择了乙二醇作为异丙醇-水分离的基本萃取剂,用Othmer汽液平衡釜分别测定了异丙醇-水-乙二醇、异丙醇-水-乙二醇+碱(氢氧化钾或氢氧化钠)和异丙醇-水-乙二醇+盐(醋酸钾)体系在溶剂比分别为0.5:1、1:1、2:1时的常压汽液... 详细信息

通过UNIFAC方程选择了乙二醇作为异丙醇-水分离的基本萃取剂,用Othmer汽液平衡釜分别测定了异丙醇-水-乙二醇、异丙醇-水-乙二醇+碱(氢氧化钾或氢氧化钠)和异丙醇-水-乙二醇+盐(醋酸钾)体系在溶剂比分别为0.5:1、1:1、2:1时的常压汽液平衡数据,结果表明,乙二醇加碱或加盐后的复合溶剂比纯溶剂更利于增大异丙醇-水的相对挥发度,在考察的复合溶剂中,以乙二醇+氢氧化钾(0.15g·mL-1乙二醇)和乙二醇+醋酸钾(0.15g·mL-1乙二醇)效果最佳。用以上两种选出的复合溶剂作为异丙醇-水分离的萃取剂,在填料塔内进行萃取精馏分离实验,通过进料位置和回流比等工艺条件的优化,分别得到了99.58%(wt)和98.68%(wt)的异丙醇,进一步表明乙二醇+碱和乙二醇+盐是异丙醇-水分离的优良复合溶剂,由于碱类对设备材质要求比盐类低,因此,加碱复合溶剂可作为萃取精馏复合溶剂选择的重要方向。

关键词：异丙醇-水乙二醇溶剂加碱溶剂加盐汽液平衡萃取精馏

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对称等离子体激励器系统电场仿真研究

物理学报 2007年第8期56卷 4778-4784页

作者：安治永李应红吴云苏长兵宋慧敏空军工程大学工程学院西安710038

采用电磁场数值计算的时域有限差分法,对用于产生等离子体的对称结构激励器系统进行了电场仿真,并对等离子体流动控制机理进行了分析.得出了与理论分析一致的用于蠕动加速的对称等离子体激励器的电场分布.这对于提高蠕动加速速度和激励... 详细信息

采用电磁场数值计算的时域有限差分法,对用于产生等离子体的对称结构激励器系统进行了电场仿真,并对等离子体流动控制机理进行了分析.得出了与理论分析一致的用于蠕动加速的对称等离子体激励器的电场分布.这对于提高蠕动加速速度和激励器的结构优化具有一定的意义.

关键词：蠕动加速等离子体时域有限差分电流体动力

Nucleation and growth of Fe-rich phases in Al-5Ti-1B modified Al-Fe alloys investigated using synchrotron X-ray imaging and electron microscopy

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Journal of Materials Science & Technology 2021年第21期80卷 84-99页

作者： Yuliang Zhao Weiwen Zhang Dongfu song Bo Lin Fanghua Shen Donghai Zheng ChunXiao Xie Zhenzhong Sun Yanan Fu runxia Li Neutron Scattering Technical Engineering Research Centre School of Mechanical EngineeringDongguan University of TechnologyDongguan523808China Guangdong-hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology Dongguan University of TechnologyDongguan523808China National Engineering Research Centre of Near-net-shape Forming for Metallic Materials South China University of TechnologyGuangzhou510641China Guangdong Institute of Materials and Processing Guangdong Acadamy of ScienceGuangzhou510650China School of Mechanical Engineering Guizhou UniversityGuiyang550025China Shanghai Synchrotron Radiation Facility.Shanghai Advanced Research Institute CASShanghai201204China School of Materials Science and Engineering Dongguan University of TechnologyDongguan523808China

Plate-like Fe-rich intermetallic phases directly influence the mechanical properties of recycled Al alloys;thus, many attempts have been made to modify the morphology of these phases. Through synchrotron X-ray imaging and electron microscopy, the underlying nucleation and growth mechanisms of Fe-rich phases during the solidification of Al-5 Ti-1 B-modified Al-2 Fe alloys were revealed in this study. The results showed that the Al-5 Ti-1 B grain refiner as well as the applied pressure both resulted in reduction of the size and number of primary Al_(3)Fe phases and promoted the formation of eutectic Al_(6)Fe *** tomography results demonstrated that Al-5 Ti-1 B changed the three-dimensional(3 D) morphology of primary Fe-rich phases from rod-like to branched plate-like, while a reduction in their thickness and size was also observed. This was attributed to the fact that Ti-containing solutes in the melts inhibit the diffusion of Fe atoms and the Al_(3)Fe twins produce re-entrant corner on the twin boundaries along the growth direction. Moreover, the TiB_(2) provides possible nucleation sites for Al_6Fe phases. The nucleation mechanism of Fe-rich phases is discussed in terms of experimental observations and crystallography calculations. The decrease in the lattice mismatch between TiB_(2) and Al_(6)Fe phases was suggested, which promoted the transformation of Al_(3)Fe to Al_(6)Fe phases.

关键词： Al alloys Synchrotron X-ray imaging Fe-rich phases Grain refinement Nucleation and growth