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Tribological properties of plasma-sprayed nickel alloy matrix self-lubricating coating at elevated temperatures

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Rare Metals 2021年第7期40卷 1844-1850页

作者： Wen-Sheng Li Yang Sun Wei Hu Sheng-Yu Zhu hai-min Zhai Jun Yang Xiang-Juan Fan Wei-min Liu State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals School of Materials Science and EngineeringLanzhou University of TechnologyLanzhou 730050China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

A nickel alloy matrix high-temperature self-lubricating coating(77.5 wt%(Ni-Cr-Mo-Al)-12.5 wt%Ag-10 wt%BaF2/CaF2)was prepared by plasma spraying *** show that the Vickers microhardness of coating is(2.9±0.5)GPa,and the average bonding strength is about(35.6±0.5)*** coating rubbing against Inconel 718 superalloy pin exhibits superior tribological performance with coefficient of friction(COF)of below 0.25 and wear rate of 8.2×10^(-5)-15.2×10^(-5)mm^(3)·N^(-1)·m^(-1)at a wide temperature range from 25 to 800℃,and the COF and the wear rate are slightly reduced with temperature *** low COF and wear rate were attributed to the synergistic effects of Ag,BaF_(2)/CaF_(2),Ag2MoO_(4)and BaMoO_(4).

关键词： Coating Tribological behavior High temperature Self-lubricating

肝肠胞虫对凡纳滨对虾肠道和肝胰腺菌群的影响

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水生生物学报 2024年第2期48卷 315-323页

作者：李舢舢赵晨曦吴波郑侠飞戴文芳林志华柳敏海浙江万里学院宁海海洋生物种业研究院浙江省水产种质资源高效利用技术研究重点实验室宁波315000

利用16S rRNA高通量测序对比研究了健康对虾和感染肝肠胞虫的发病对虾肠道及肝胰腺菌群的组成、多样性、微生物介导的功能和种间互作间的差异性。结果表明,健康对虾的肠道和肝胰腺细菌群落的多样性高于发病对虾。在属水平上,健康对虾和... 详细信息

利用16S rRNA高通量测序对比研究了健康对虾和感染肝肠胞虫的发病对虾肠道及肝胰腺菌群的组成、多样性、微生物介导的功能和种间互作间的差异性。结果表明,健康对虾的肠道和肝胰腺细菌群落的多样性高于发病对虾。在属水平上,健康对虾和发病对虾的肠道及肝胰腺中的优势细菌组成及丰度存在明显不同,其中健康对虾肠道中的优势菌属主要为埃希杆菌-志贺菌属(Escherichia-Shigella)和海绵菌属(Spongiimonas),而发病对虾肠道中的优势菌属则为希瓦式菌属(Shewanella)、巨球型菌属(Megasphaera)和克雷伯氏菌属(Klebsiella);健康对虾肝胰腺中的优势菌属主要为假单胞菌属(Pseudomonas)和汉氏盐单胞菌(Halomonas),而发病对虾肝胰腺中的优势菌属则为贪铜菌属(Cupriavidus)。Tax4Fun2预测显示,健康对虾肠道和肝胰腺菌群的主要功能分别与发病对虾肠道和肝胰腺菌群的主要功能有明显差异。研究有助于了解肝肠胞虫对凡纳滨对虾肠道及肝胰腺细菌群落的影响,并为凡纳滨对虾的健康管理和养殖提供依据。

关键词：肠道菌群 16S rRNA测序功能预测凡纳滨对虾

维普期刊数据库博看期刊

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汽车空调流体管路的气动噪声分析与优化

机械设计与制造 2024年第7期 269-272页

作者：万里翔闵海娇刘晓昂王新玲西南交通大学机械工程学院四川成都610031 雪龙集团有限公司浙江宁波315806

以汽车空调风道为研究对象,在Fluent中采用RNG模型和LES模型对管路进行稳态和瞬态计算,对风道出口风量进行试验验证,并采用声类比法计算风道出风口的噪声。根据仿真分析结果,采用响应面法,以出风口1管路的转角半径、出风口2管路左、右... 详细信息

以汽车空调风道为研究对象,在Fluent中采用RNG模型和LES模型对管路进行稳态和瞬态计算,对风道出口风量进行试验验证,并采用声类比法计算风道出风口的噪声。根据仿真分析结果,采用响应面法,以出风口1管路的转角半径、出风口2管路左、右管壁的移动距离为设计变量,以出风口2的风量占比为优化目标对空调管路的结构进行优化。最后对优化前、后的管路进行了流场和声场对比分析。结果表明,与原模型相比,优化后风道出风口2的风量比例由20.75%提升到了25.25%,出风口的噪声下降最大值为5.15dB。

关键词：空调风道气动噪声计算流体力学响应面法

A Performance Evaluation of Classic Convolutional Neural Networks for 2D and 3D Palmprint and Palm Vein Recognition

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International Journal of Automation and computing 2021年第1期18卷 18-44页

作者： Wei Jia Jian Gao Wei Xia Yang Zhao hai min Jing-Ting Lu School of Computer Science and Information Engineering Hefei University of TechnologyHefei 230009China Anhui Province Key Laboratory of Industry Safety and Emergency Technology Hefei 230009China Institution of Industry and Equipment Technology Hefei University of TechnologyHefei 230009China

Palmprint recognition and palm vein recognition are two emerging biometrics *** the past two decades,many traditional methods have been proposed for palmprint recognition and palm vein recognition,and have achieved impressive ***,the research on deep learningbased palmprint recognition and palm vein recognition is still very *** this paper,in order to investigate the problem of deep learning based 2D and 3D palmprint recognition and palm vein recognition indepth,we conduct performance evaluation of seventeen representative and classic convolutional neural networks(CNNs)on one 3D palmprint database,five 2D palmprint databases and two palm vein databases.A lot of experiments have been carried out in the conditions of different network structures,different learning rates,and different numbers of network *** have also conducted experiments on both separate data mode and mixed data *** results show that these classic CNNs can achieve promising recognition results,and the recognition performance of recently proposed CNNs is ***,among classic CNNs,one of the recently proposed classic CNNs,i.e.,EfficientNet achieves the best recognition ***,the recognition performance of classic CNNs is still slightly worse than that of some traditional recognition methods.

关键词： Performance evaluation convolutional neural network(CNN) biometrics palmprint palm vein deep learning

Preparation and performance of a cold gas dynamic sprayed high-aluminum bronze coating

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International Journal of minerals,Metallurgy and Materials 2018年第11期25卷 1354-1361页

作者： Li Feng Chang Guan Ji-rong Chang hai-min Zhai Guo-sheng An Wen-sheng Li School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou 730050China State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou 730050China

By mixing preheated high-aluminum bronze powders with different amounts of Al_2O_3 powder, a low-pressure cold-sprayed coating was prepared and sprayed onto a Cr12MoV steel substrate. The hardness of the coating and the bonding strength between the coating and the substrate were tested with a HV-1000 microhardness tester and a mechanical universal testing machine. The surface microstructure, cross-section and tensile fracture surface of the coating were observed with a scanning electron microscope(SEM). Correspondingly, the influences of the preheat treatment temperature of the bronze powder and the Al_2O_3 content on the coating performance were investigated. The results indicate that the hardness of bronze powders decreased and the coating deposition rate increased after the preheating treatment of the bronze powder. The Al_2O_3 content in the mixed powders contributed to the deformation of bronze powders during the spraying process. This trend resulted in varied performance of the coating.

关键词： low-pressure cold spray high-aluminum bronze preheat treatment coating performance

Determination of the Topology Skeleton of Magnetic Fields in a Solar Active Region

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Chinese Journal of Astronomy and Astrophysics 2008年第2期8卷 133-145页

作者： Hui Zhao Jing-Xiu Wang Jun Zhang Chi-Jie Xiao hai-min Wang National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 Big Bear Solar Observatory 40386 North Shore Lane Big Bear City CA 92314 USA

Magnetic topology has been a key to the understanding of magnetic energy release mechanism. Based on observed vector magnetograms, we have determined the threedimensional （3D） topology skeleton of the magnetic fields in the active region NOAA 10720. The skeleton consists of six 3D magnetic nulls and a network of corresponding spines, fans, and null-null lines. For the first time, we have identified a spiral magnetic null in Sun＇s corona. The magnetic lines of force twisted around the spine of the null, forming a ＇magnetic wreath＇ with excess of free magnetic energy and resembling observed brightening structures at extraultraviolet （EUV） wavebands. We found clear evidence of topology eruptions which are referred to as catastrophic changes of topology skeleton associated with a coronal mass ejection （CME） and an explosive X-ray flare. These results shed new lights on the structural complexity and its role in explosive magnetic activity. The concept of flux rope has been widely used in modelling explosive magnetic activity, although their observational identity is rather obscure or, at least, lacking of necessary details up to date. We suggest that the magnetic wreath associated with the 3D spiral null is likely an important class of the physical entity of flux ropes.

关键词： Sun: magnetic fields -- Sun: solar corona -- Sun: activity

人工智能技术赋能开放教育大学英语教学创新实践研究

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广东开放大学学报 2024年第3期33卷 7-14页

作者：申志华米海敏赵慧霞李琪邯郸开放大学河北邯郸056000 河北开放大学河北石家庄050081 邢台开放大学河北邢台054000 国家开放大学北京100039

随着5G技术的兴起和人工智能技术的持续进步,教育领域对人工智能赋能教育的重视程度日益加深,这种趋势预示着教育方式的革新与提升。本研究以邯郸开放大学2022年春季入学的43名非英语专业本科生为样本,采用OPEN模式,借助人工智能技术、... 详细信息

随着5G技术的兴起和人工智能技术的持续进步,教育领域对人工智能赋能教育的重视程度日益加深,这种趋势预示着教育方式的革新与提升。本研究以邯郸开放大学2022年春季入学的43名非英语专业本科生为样本,采用OPEN模式,借助人工智能技术、移动设备和国家开放大学学习网平台的公共英语精品课,开展了教学创新实践研究。通过使用各种脚手架来设计一体化的弹性学习活动,基于ARCS动机驱动模型设计学习任务清单,结合在线学习的SERI模型制定了评价量表。经过一年的实践教学干预和多维度数据收集,统计分析结果显示,实验组学生的测试成绩明显优于对照组。

关键词：人工智能开放教育大学英语 OPEN模式教学创新

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一种机械设备用起吊装置的设计

机械工程与自动化 2024年第5期 123-124页

作者：韩海敏韩一庆光孟坷河南应用技术职业学院河南郑州450042 河南理工大学能源科学与工程学院河南焦作454000

针对起吊装置在使用过程中存在的功能单一、能耗大、取放效率低、需要人工查找等问题,设计了一种适用于机械设备的改进型起吊装置。基于轻量化、自动化、安全化的设计要求,确定了起吊装置的机械整体结构,详细介绍了装置中的升降机构、... 详细信息

针对起吊装置在使用过程中存在的功能单一、能耗大、取放效率低、需要人工查找等问题,设计了一种适用于机械设备的改进型起吊装置。基于轻量化、自动化、安全化的设计要求,确定了起吊装置的机械整体结构,详细介绍了装置中的升降机构、放置机构及工作原理。该装置升降稳定、控制精准,可节省人工成本,并降低了安全隐患,实现了自动化取放,有利于提高起吊作业的工作效率。

关键词：起吊装置机械设备自动化取放

Synthesis and Crystal Structure of (E)-4-(Benzyloxy)-2-(cinnamoyloxy)-N,N,N-trimethyl-4-oxobutan-1-aminium Chloride as a Double-prodrug

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Chinese Journal of Structural Chemistry 2008年第2期27卷 177-182页

作者： GONG Xiao-Wei LI Xun LI Wei-Lu GAO Xu XU Wen-Fang Zhai hai-min College of Pharmacy Shandong University Jinan 250012 China Shandong Medical College Jinan 250002 China Stomatology Hospital Shandong University Jinan 250012 China Qidu Pharmaceutical Co. LTD Zibo 255400 China

A novel hydrochloride quaternary ammonium salt （E）-4-（benzyloxy）-2-（cinnamo- yloxy）-N,N,N-trimethyl-4-oxobutan-l-aminium chloride （Cz3HzgNO4Cl2, Mr = 454.37） has been synthesized via the sequence of acetylation and esterification by using L-carnitine （L-4-N-trimethy- lammonium-3-hydroxybutyric acid, LC） and cinnamic acid as the starting materials, and its crystal structure was determined by single-crystal X-ray diffraction method. The crystal belongs to monoclinic, space group P212121 with a = 10.1670（4）, b = 10.4488（4）, c = 22.9795（11）A, V = 2441.18（18）A3, Z = 4, Dc = 1.236 g/cm3,μ（MoKa） = 0.293 mm-1, F（000） = 960, Flack factor = -0.01（11）, the final R = 0.0489 and wR = 0.1550 for 3350 observed reflections （I 〉 2σ（/）） and R = 0.0953 for all 5648 unique reflections. The crystal structure involves a conjugated system which shows a reverse olefin structure.

关键词： L-caruitine cinnamic acid synthesis crystal structure