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Design of a PCB stator coreless axial flux permanent magnet synchronous motor based on a novel topology Halbach array
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作者 Xiao-yuan WANG Xiang LI +2 位作者 Chun-peng LI Si-jia XU Le-tao LING 《信息与电子工程前沿:英文版》 SCIE EI CSCD 2019年第3期414-424,共11页
A novel topology Halbach permanent magnet array is proposed and applied to the design of a printed circuit board(PCB) axial flux permanent magnet(AFPM) motor. Compared with the traditional coreless AFPM motor, this no... A novel topology Halbach permanent magnet array is proposed and applied to the design of a printed circuit board(PCB) axial flux permanent magnet(AFPM) motor. Compared with the traditional coreless AFPM motor, this novel topology for a Halbach permanent magnet array PCB stator AFPM motor has larger air-gap magnetic flux density and air-gap flux per pole. The magnetic flux leakage is effectively reduced, and the air-gap magnetic density is close to the sine wave. Results of the finite element analysis and prototype experiments verify the feasibility and effectiveness of the novel Halbach permanent magnet array PCB stator motor. A reference basis and practical value for the design of the PCB AFPM motor are provided. 展开更多
关键词 Axial flux PERMANENT MAGNET SYNCHRONOUS motor Printed circuit board HALBACH PERMANENT MAGNET array Finite element method
Magnet Attract Shell during Head and Neck Surgery 预览
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作者 Ahmed Khalaf Rabeea 《耳鼻喉(英文)》 2019年第5期171-179,共9页
Objective: New method to use magnet for localization and extraction of shell during head and neck surgery. Method: Series of 3 cases study all are boy’s 17_15_5 years old respectively. All are with penetrating shell ... Objective: New method to use magnet for localization and extraction of shell during head and neck surgery. Method: Series of 3 cases study all are boy’s 17_15_5 years old respectively. All are with penetrating shell injuries to head and neck in Salahaden General Hospital-Tikrit city-Iraq from 25-Oct.-2016 to 30 March 2017. This hospital is a central general governmental hospital that receives referral cases from region distal to the center of Salahaden province at north of Baghdad city (capital of Iraq) and plays a major rule in management of injured patient during war. The cases are selected after explanation of this new method to the patients, it is expected result, risk, possible complication, and unexpected sequelae that may happen after surgery. Prior consent from patients and their families about this sort of surgery has been got. These patients are from families of low socio economic group except the last one he is medium class. All are undergoing surgical management with the aid of magnet. Result: we have 3 cases of shell injuries to head and neck magnet is used successfully for identification of shells and helps in their extraction. Our trial is limited for metallic objects and limited depth. Conclusion: These results suggest that magnet aid removal of shell during head and neck surgery, is less invasive technique, minimal trauma to the surrounding tissues and reducing time of surgery. 展开更多
关键词 MAGNET SHELL INJURIES HEAD and NECK
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筒式磁力耦合器的结构参数对传动性能的影响 预览
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作者 张小锋 袁爱仁 吴盈志 《机械设计与制造》 北大核心 2019年第10期189-192,196共5页
转矩是磁力耦合器传动性能的重要指标之一,为获得单位体积内磁力耦合器具有最大传动转矩时的磁路结构参数,以永磁体间隙排列的筒式实心磁力耦合器为研究对象,运用Magnet有限元分析软件模拟分析不同长径比下,磁力耦合器的不同结构参数对... 转矩是磁力耦合器传动性能的重要指标之一,为获得单位体积内磁力耦合器具有最大传动转矩时的磁路结构参数,以永磁体间隙排列的筒式实心磁力耦合器为研究对象,运用Magnet有限元分析软件模拟分析不同长径比下,磁力耦合器的不同结构参数对转矩和转矩密度的影响,得到磁力耦合器的最佳结构参数:永磁体的极弧系数为0.8,磁极对数为6,铜环厚度为4mm,铜环长厚比为1,通过模拟分析该结构参数下的磁力耦合器的机械特性,得到磁力耦合器的输出转矩与输出转速的关系曲线,相较于筒式鼠笼转子磁力耦合器,改进后的磁力耦合器在恒负载工况下具有较大的稳定运行区间,且滑差率为66%时具有最大的传动转矩。 展开更多
关键词 筒式实心磁力耦合器 MAGNET 转矩密度 极弧系数 机械特性
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A{Tb2Fe3}Pyramid Single-Molecule Magnet with Ferromagnetic Tb-Fe Interaction
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作者 Han Li Xixi Meng +3 位作者 Mengmeng Wang Yu-Xia Wang Wei Shi Peng Cheng 《中国化学:英文版》 SCIE CAS CSCD 2019年第4期373-377,共5页
The influence of magnetic interactions to the magnetization dynamics was well experimentally studied in a 3d-4f single-molecule magnet(SMM)[Tb^Ⅲ2Fe^Ⅲ3(μ5-O)L2(NO3)4Cl](1,H4L=N,N,N′,N′-tetrakis(2-hydroxyethyl)ethy... The influence of magnetic interactions to the magnetization dynamics was well experimentally studied in a 3d-4f single-molecule magnet(SMM)[Tb^Ⅲ2Fe^Ⅲ3(μ5-O)L2(NO3)4Cl](1,H4L=N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylene diamine)and its diamagneticion-diluted samples.Significant ferromagnetic coupling between Tb^Ⅲ and Fe^Ⅲ ions and SMM behavior of 1 were observable,which proved clearly that the magnetic interaction between 3d-4f spin carriers has also an excessive impact on fine-tuning the magnetization dynamic behaviors of 3d-4f complexes. 展开更多
关键词 A{Tb2Fe3}Pyramid SINGLE-MOLECULE Magnet FERROMAGNETIC Tb-Fe INTERACTION magnetization dynamic behaviors
附磁压电悬臂梁流致振动俘能特性分析 预览
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作者 曹东兴 马鸿博 张伟 《力学学报》 EI CSCD 北大核心 2019年第4期1148-1155,共8页
流致振动蕴含巨大的能量,本文基于流致振动理论,设计了一种附加磁力激励的压电悬臂梁流致振动俘能器,并通过理论和实验研究其振动俘能特性.该俘能器由压电悬臂梁、圆柱绕流体和磁铁组成;首先基于Euler-Bernoulli梁理论,推导了流致振动... 流致振动蕴含巨大的能量,本文基于流致振动理论,设计了一种附加磁力激励的压电悬臂梁流致振动俘能器,并通过理论和实验研究其振动俘能特性.该俘能器由压电悬臂梁、圆柱绕流体和磁铁组成;首先基于Euler-Bernoulli梁理论,推导了流致振动附磁压电俘能器的能量函数,利用Hamilton原理建立了流致振动附磁压电俘能器的机电耦合方程;利用数值方法研究详细分析了流速、圆柱绕流体直径和长度、磁间距、磁极和外接电阻等系统参数对压电俘能器振动特性和输出电压的影响.分析结果表明,该型压电俘能器的振动幅值在低流速条件下产生涡激振动,并产生最大的输出电压;磁力可以降低压电俘能器的共振频率并能够拓宽压电俘能器频带带宽,因此,附磁压电俘能器具有相比没有附磁的压电俘能器更适用于低速层流环境;实验结果与数值结果吻合较好,验证了附磁压电悬臂梁流致振动俘能器的理论分析的正确性. 展开更多
关键词 振动能量采集 流致振动 圆柱绕流 压电悬臂梁 磁力
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胃肠道病变磁体预标记辅助腹腔镜定位术初探
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作者 任牡丹 马锋 +7 位作者 孙学军 严小鹏 赵伟 郑见宝 马文慧 卢新兰 和水祥 卢桂芳 《中华消化内镜杂志》 CSCD 北大核心 2019年第11期821-825,共5页
目的评估胃肠道病变磁体预标记辅助腹腔镜定位术的可行性及安全性。方法2019年4月至6月,拟行腹腔镜根治术的胃、结直肠肿瘤住院患者8例,在行腹腔镜切除术前接受了内镜下磁体预标记,即在病变旁用钛夹固定一枚磁体进行病变标记。术中通过... 目的评估胃肠道病变磁体预标记辅助腹腔镜定位术的可行性及安全性。方法2019年4月至6月,拟行腹腔镜根治术的胃、结直肠肿瘤住院患者8例,在行腹腔镜切除术前接受了内镜下磁体预标记,即在病变旁用钛夹固定一枚磁体进行病变标记。术中通过腹腔镜孔道送入另一枚磁体,在磁体相互吸引力导引下,快速与病变附近预标记的磁体隔胃肠道壁而吸引在一起,实现病变定位。对8例患者的术前标记及手术情况进行分析和总结。结果8例患者术前均内镜下成功标记病灶,并实现了术中快速准确定位。内镜下标记用时为(5.75±2.45)min,术中定位用时(1.94±0.56)min。患者均完成腹腔镜肿瘤切除术,定位准确,结直肠肿瘤病灶平均近端和远端切除边缘分别为105 mm和74 mm,无任何并发症发生。结论胃肠道病变磁体预标记辅助腹腔镜定位术简便、安全、准确,同时无需额外诊治设备及消化内镜术中配合操作。 展开更多
关键词 胃肠道 腹腔镜 定位 磁体
Disturbance Observer Based Speed Control of PMSM Using Fractional Order PI Controller 预览
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作者 Aishwarya Apte Ujjwala Thakar Vrunda Joshi 《自动化学报:英文版》 CSCD 2019年第1期316-326,共11页
In this paper, fractional order PI(FOPI) control is developed for speed control of permanent magnet synchronous motor(PMSM). Designing the parameters for FOPI controller is a challenging task, especially for nonlinear... In this paper, fractional order PI(FOPI) control is developed for speed control of permanent magnet synchronous motor(PMSM). Designing the parameters for FOPI controller is a challenging task, especially for nonlinear systems like PMSM.All three PI controllers in the conventional vector controlled speed drive are replaced by FOPI controllers. Design of these FOPI controllers is based on the locally linearized model of PMSM around an operating point. This operating point changes with the load torque. The novelty of the work reported here is in use of Non Linear Disturbance Observer(NLDO) to estimate load torque to obtain this new operating point. All three FOPI controllers are then designed adaptively using this new operating point. The scheme is tested on simulation using MATLAB/SIMULINK and results are presented. 展开更多
关键词 Fractional order PI (FOPI) non linear DISTURBANCE OBSERVER (NLDO) PERMANENT MAGNET SYNCHRONOUS motor(PMSM) vector control
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一种托举式磁悬浮装置的模型仿真与实现
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作者 王青 《国外电子测量技术》 2019年第9期117-120,共4页
随着科技的发展,人们对于磁悬浮技术的关注度不断提高,源于磁悬浮能够实现物体间的不接触从而能够大大减少摩擦力。针对磁悬浮系统本身的具有不稳定的特点,本设计在对磁悬浮特性及工作原理充分分析的基础上,采用磁性仿真软件Maxwell对... 随着科技的发展,人们对于磁悬浮技术的关注度不断提高,源于磁悬浮能够实现物体间的不接触从而能够大大减少摩擦力。针对磁悬浮系统本身的具有不稳定的特点,本设计在对磁悬浮特性及工作原理充分分析的基础上,采用磁性仿真软件Maxwell对永磁体及线圈相关磁性元件进行仿真以及力学分析,构建了力学、电磁学的非线性化模型,设计相关的硬件电路,完成实物的调试。通过试验,实现了悬浮磁铁质量块(26~35g)的悬浮控制,悬浮高度距大环形磁铁上表面27~47mm,悬浮稳定可靠,稳态误差小于0.1mm。 展开更多
关键词 磁悬浮 MAXWELL 电磁学 磁铁
Luminescent single-molecule magnet of metallofullerene DyErScN@Ih-C80
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作者 Mingzhe Nie Jin Xiong +8 位作者 Chong Zhao Haibing Meng Kun Zhang Yibo Han Jie Li Bingwu Wang Lai Feng Chunru Wang Taishan Wang 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第7期1727-1731,共5页
Magneto-luminescent molecules have significant applications in data storage and quantum computing.However,design of these bi-functional molecules coupled with magnetic behavior and photoluminescence is still challengi... Magneto-luminescent molecules have significant applications in data storage and quantum computing.However,design of these bi-functional molecules coupled with magnetic behavior and photoluminescence is still challenging.In this work,we report a metallofullerene DyErScN @In-C80 exhibiting single-molecule magnet (SMM) behavior and near-infrared emission.For DyErScN @Ih-C80,two functional lanthanide metal ions of Dy^3+(SMM function) and Er^3+(luminescent function) are integrated inside a fullerene cage using a trimetallic nitride template,and its structure has been unambiguously characterized by single-crystal X-ray diffraction.Magnetic measurements revealed that DyErScN @Ih-C80 behaves as a SMM with a blocking temperature up to 9 K resulting from the intramolecular magnetic interaction between Dy^3+ and Er^3+ ions.Moreover,DyErScN @In-C80 exhibits temperature-dependent near-infrared emission around 1.5 pm with multiple splitting peaks from Er^3+,which arises from the influence of Dy^3+ ion.This study provides a new strategy to synthesize new magneto-luminescent molecule materials. 展开更多
关键词 METALLOFULLERENE SINGLE-MOLECULE MAGNET NEAR-INFRARED photoluminescence
一种楞次定律实验的改进装置 预览
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作者 黄一轩 《当代化工研究》 2019年第1期146-147,共2页
楞次定律的实验验证由于时效性问题,呈现较为明显的物理现象是实验的重点和难点,为了实验效果更加直观,在显示和增加时长等方面进行了研究,根据传统楞次定律装置的缺点加以改进,通过发光二极管,电容等装置,以光、电等现象来进一步演示... 楞次定律的实验验证由于时效性问题,呈现较为明显的物理现象是实验的重点和难点,为了实验效果更加直观,在显示和增加时长等方面进行了研究,根据传统楞次定律装置的缺点加以改进,通过发光二极管,电容等装置,以光、电等现象来进一步演示楞次定律,使实验结果更加易于演示。 展开更多
关键词 发光二极管 电容 磁铁 灵敏电流计 双回路
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不同表面改性钕铁硼磁体抗胃液腐蚀的体外研究 预览
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作者 田波彦 刘豪 +10 位作者 付珊 马思捷 张砚超 邱明龙 邓博 雷蕾 叶丹 高慧敏 李益行 吕毅 严小鹏 《中国医疗设备》 2019年第3期5-8,共4页
目的比较不同表面改性钕铁硼磁体抗胃液腐蚀的能力。方法收集临床患者胃液,体外恒温38℃下浸泡裸磁、镍镀层、镍-氮化钛复合镀层、环氧树脂镀层的钕铁硼磁体,每3 d更换胃液并称取磁体质量,同时留取浸泡液检测铁离子浓度。浸泡30 d后计... 目的比较不同表面改性钕铁硼磁体抗胃液腐蚀的能力。方法收集临床患者胃液,体外恒温38℃下浸泡裸磁、镍镀层、镍-氮化钛复合镀层、环氧树脂镀层的钕铁硼磁体,每3 d更换胃液并称取磁体质量,同时留取浸泡液检测铁离子浓度。浸泡30 d后计算磁体质量丢失率,扫描电镜观察磁体表面。结果胃液浸泡30 d后,裸磁体、镍镀层、镍-氮化钛复合镀层、环氧树脂镀层组的磁体质量丢失率分别为2.74%、0.67%、0.26%、0.08%,各组间不同时间点浸泡液铁离子浓度存在差异。电镜观察结果显示各组磁体浸泡后表面出现不同程度的腐蚀斑。结论环氧树脂镀层的钕铁硼磁体抗胃液腐蚀性能明显优于镍镀层和镍-氮化钛复合镀层的磁体。 展开更多
关键词 表面改性 钕铁硼 磁体 胃液
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基于磁压榨技术的先天性肛门闭锁再通吻合装置的设计 预览
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作者 单丽宇 雷蕾 +8 位作者 邓博 叶丹 李益行 杨毓锐 袁宗玲 郝苗 吴剑华 吕毅 严小鹏 《中国医疗设备》 2019年第3期12-14,34共4页
目的设计基于磁压榨技术的肛门闭锁再通吻合装置。方法分析先天性肛门闭锁疾病的特点,结合磁压榨技术的原理,设计微创下磁压榨肛门闭锁再通吻合装置。结果通过特殊形状设计的磁压榨吻合装置,借助穿刺技术在肛穴中心部位与直肠盲端建立... 目的设计基于磁压榨技术的肛门闭锁再通吻合装置。方法分析先天性肛门闭锁疾病的特点,结合磁压榨技术的原理,设计微创下磁压榨肛门闭锁再通吻合装置。结果通过特殊形状设计的磁压榨吻合装置,借助穿刺技术在肛穴中心部位与直肠盲端建立穿刺道,纺锤状子磁体沿穿刺针置入直肠盲端,将与子磁体配套的带沉孔的圆柱状母磁体置于肛穴部位,子母磁体相吸并压榨可实现肛门闭锁的重建再通。结论该设计基于磁压榨吻合原理,设计巧妙、操作简便、创伤小、安全性高,具有很大的临床应用价值。 展开更多
关键词 磁压榨技术 肛门闭锁 磁外科 磁体
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Coercivity kinetics upon step annealing of sintered Sm(Co0.88-xFexCu0.09Zr0.03)7 magnets
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作者 A.G.Popov O.A.Golovnia +3 位作者 A.V.Protasov V.S.Gaviko D.A.Kolodkin R.Gopalan 《中国稀土学报:英文版》 SCIE EI CAS CSCD 2019年第10期1059-1065,共7页
Behavior of the coercivity of the high-temperature Sm(Co0.88-xFexCu0.09Zr0.03)7 magnets depending on the temperature and time of annealing with the temperature decreasing stepwise from 700 to 400℃ was investigated.It... Behavior of the coercivity of the high-temperature Sm(Co0.88-xFexCu0.09Zr0.03)7 magnets depending on the temperature and time of annealing with the temperature decreasing stepwise from 700 to 400℃ was investigated.It is shown that the growth rate of coercivity abruptly increases at the initial stage of annealing in the vicinity of the Curie temperature of the SmCo5 phase.The origin of the effect is the counter diffusion of Cu and Co atoms through dislocation tubes,which form because of enhanced stresses and a partial breakage of coherent coupling at the interface of the Sm2 Co17 and SmCo5 phases.Diffusive enrichment of the SmCo5 phase in Cu close to the interface with Sm2 Co17 leads to relaxation of stresses and increases in the gradient of the magnetic domain-wall energy and coercivity. 展开更多
关键词 Sm-Co-Fe-Cu-Zr Permanent magnet SM2CO17 SMCO5 COERCIVITY KINETICS
Recovering REEs from NdFeB wastes with high purity and efficiency by leaching and selective precipitation process with modified agents
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作者 Yilan Tian Zhongwu Liu Guoqing Zhang 《中国稀土学报:英文版》 SCIE EI CAS CSCD 2019年第2期205-210,共6页
A leaching and selective precipitation approach is proposed in this work to recover rare earth elements(REEs) from NdFeB magnet wastes collected from industry. Hydrochloric acid and oxalic acid were employed as the le... A leaching and selective precipitation approach is proposed in this work to recover rare earth elements(REEs) from NdFeB magnet wastes collected from industry. Hydrochloric acid and oxalic acid were employed as the leaching and precipitation agents, respectively. Hexamethylenetetramine(HMTA) or tartaric acid was used as the chelating agent during leaching. Both leaching and precipitation processes were optimized individually. For leaching process, the effects of two different chelating agents, the concentrations of leaching agent, chelating agent, and temperature on the extraction and recovery yields were investigated. The optimized process based on the factorial experiment was determined to be the hydrochloric acid concentration of 6 mol/L, the tartaric acid concentration of 50 g/L, and the temperature of 313 K, by which the extraction yields of Fe and REEs up to 67.99% and 99.27%, respectively, are obtained. For the precipitation process, the optimized oxalic acid dosage and pH value were also determined. The produced RE oxide products have the purity and recovery yield up to 95.83% and 90.18%,respectively. These results indicate that the present method with low acid consumption and high product purity has advantages over many other approaches for REE recovery. 展开更多
关键词 RARE-EARTH PERMANENT MAGNET ND-FE-B Waste management Recovery LEACHING Precipitation
具有自调节通风性能的大型永磁同步发电机内流热特性数值研究 预览
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作者 朱敏 丁树业 +1 位作者 江欣 刘玮 《南京师范大学学报:工程技术版》 CAS 2019年第1期1-7,共7页
为了探究具有自调节通风功能的结构紧凑型大型永磁同步发电机内部流体流变特性及温升分布规律,以一台6 MW永磁同步发电机为例,基于电机学和数值传热学理论,结合流-热耦合机理,根据电机实际冷却结构选择一个周期作为求解域,建立三维流体... 为了探究具有自调节通风功能的结构紧凑型大型永磁同步发电机内部流体流变特性及温升分布规律,以一台6 MW永磁同步发电机为例,基于电机学和数值传热学理论,结合流-热耦合机理,根据电机实际冷却结构选择一个周期作为求解域,建立三维流体场与温度场耦合分析数学模型及物理模型.采用有限体积元法对永磁同步电机三维温度场进行数值研究,对发电机定转子铁心、定子绕组与绝缘以及永磁体的温升分布特性进行详细分析.通过与电机绝缘温升限值的对比分析,验证了其求解方法的合理性以及计算结果的准确性,为永磁同步发电机温升的计算及通风结构的设计提供参考依据. 展开更多
关键词 永磁同步发电机 流-热耦合 三维温度场 有限体积元 数值计算
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Tailoring the mechanical anisotropy of sintered NdFeB magnets by Pr-Cu grain boundary reconstruction
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作者 Minghui Tang Xiaoqian Bao +4 位作者 Xuejiao Zhang Xing Mu Kechao Lu Jiheng Li Xuexu Gao 《中国稀土学报:英文版》 SCIE EI CAS CSCD 2019年第4期393-397,共5页
Pr83Cu17(wt%) grain boundary reconstruction was applied to prepare sintered NdFeB magnets. The effects of addition amount and annealing on the bending strength were investigated. The results show that Pr83Cu17 can not... Pr83Cu17(wt%) grain boundary reconstruction was applied to prepare sintered NdFeB magnets. The effects of addition amount and annealing on the bending strength were investigated. The results show that Pr83Cu17 can not only effectively enhance the bending strength, but also change the mechanical anisotropy in two directions parallel and perpendicular to c-axis. The bending strength perpendicular to c-axis reaches 404 MPa in 10 wt% addition magnet, higher than 348 MPa along parallel direction. This change is attributed to the preferred distribution of boundary phases, i.e., ductile(Nd,Pr)-Fe-Cu phase along perpendicular direction to c-axis and(Nd,Pr)-Fe phase along parallel direction. Moreover, the Cu migration during 480 ℃ annealing is found to be related to this boundary phase distribution. 展开更多
关键词 Mechanical properties Sintered ND-FE-B MAGNET Pr-Cu alloy Rare earths
Influence of Al/Cu content on grain boundary diffusion in Nd-Fe-B magnet via in-situ observation
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作者 Xinghua Cheng Jian Li +3 位作者 Lei Zhou Tao Liu Xiaojun Yu Bo Li 《中国稀土学报:英文版》 SCIE EI CAS CSCD 2019年第4期398-403,共6页
The influence of aluminum and copper content in the starting Nd-Fe-B magnet on grain boundary diffusion process(GBDP) was studied by observing the phase transformation behaviors of the magnets in-situ at high temperat... The influence of aluminum and copper content in the starting Nd-Fe-B magnet on grain boundary diffusion process(GBDP) was studied by observing the phase transformation behaviors of the magnets in-situ at high temperature. A higher coercivity increment is discovered in the sample with higher AI/Cu despite the fact that its Dy diffusion amount is the same as the other. DSC analysis shows an evident melting behavior in the higher Al/Cu sample. Laser scanning confocal microscopy(LSCM) in-situ characterization shows a large amount of melted intergranular phase spills out to the surface simultaneously at around 600 ℃ in the high Al/Cu sample, while the phase spills out gradually one after another in the range between 623 and680 ℃ in the other sample, which indicates that the intergranular phase can be more easily melted in the sample containing more AI/Cu. The area fraction of matrix phase remarkably shrinks while that of intergranular phase enlarges after LSCM heating, which demonstrates the outer region of the Nd2 Fe14B grains melt at the temperature of 900 ℃. Electron probe microanalyzer result(EPMA) shows that the Nd and Dy concentrate in edge regions and subsequently mix into the intergranular phase with the melting of the grain edge, while a large amount of AI and Cu in the intergranular phase spill out. Nevertheless, the sample with higher starting AI/Cu still remains higher residual contents after LSCM experiments, and that could probably be the main reason why the high AI/Cu magnet shows smaller coercivity decrement after LSCM experiment. Overall, the increase of AI/Cu in the starting magnet optimizes the Dy distribution and the wettability of intergranular phase, enhancing coercivity increment effect further. 展开更多
关键词 ND-FE-B sintered MAGNET Grain boundary diffusion process IN-SITU LSCM MELTING behavior Copper Aluminum
CTFEL装置磁铁设计和测量
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作者 闫陇刚 崔玉柱 +5 位作者 张浩 邓德荣 李青 朱应顺 杨兴繁 黎明 《核技术》 CAS CSCD 北大核心 2019年第10期13-18,共6页
中国工程物理研究院太赫兹自由电子激光装置CTFEL(China Academy of Engineering Physics Terahertz Free Electron Laser,CAEP THz FEL)是国内首台可为用户提供高功率和宽谱太赫兹波的科学设施,CTFEL作为基于加速器的辐射源,磁铁是电... 中国工程物理研究院太赫兹自由电子激光装置CTFEL(China Academy of Engineering Physics Terahertz Free Electron Laser,CAEP THz FEL)是国内首台可为用户提供高功率和宽谱太赫兹波的科学设施,CTFEL作为基于加速器的辐射源,磁铁是电子束团的传输、测量和操纵的重要部件之一。根据CTFEL装置磁铁的指标参数设计了磁铁,针对设计中遇到的问题,阐述了解决思路,测量了磁场分布、积分场分布、横向场分布和磁轴等,测试结果表明:所有磁铁都满足了指标要求。目前磁铁已经全部完成了安装和调试,保障了CTFEL装置的顺利出光。 展开更多
关键词 CTFEL 磁铁 结构设计 磁场测量
Electrification Solution with Supercapacitor Storage of a Bow Thruster for River Tugboat 预览
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作者 Alexandre De Bernardinis Jeff Moussodji 《能源与动力工程:英文版》 2019年第2期43-58,共16页
Bow thrusters usually are hydraulic and mechanically driven engines,used for the positioning maneuvers of River and sea boats.The peculiarity of these systems operating on short time intervals is their low rate of use... Bow thrusters usually are hydraulic and mechanically driven engines,used for the positioning maneuvers of River and sea boats.The peculiarity of these systems operating on short time intervals is their low rate of use(approximately 2%)but requiring maximal power.The main purpose of the work is to propose an innovative electrical hybridization of the bow thruster for a river tugboat.This electrification solution enables the bow thruster to operate with no-emissions,reduced noise and is a subsystem of green ship.Main challenge is to manage high torque and low speed requirements of the bow thruster system during the positioning maneuvers,by adding a dynamic electrical storage system,based on high capacitance value Supercapacitors,and in association with the electrified propeller motor.The knowledge concerns hybrid electrification,involving new-technology elements,energy storage based on supercapacitors,the high amplitude low speed torque control strategy.With fully reversible electrical motorization,the propeller is able to operate for both direct-reverse ways of rotation.Proposed electrical solution would hence provide large expected benefits in terms of energy efficiency,compactness,weights,costs,and contribute to a more eco-friendly ship.Numerical simulation and first results on laboratory test bench validate the proposed electrification concept. 展开更多
关键词 Energy storage marine navigation PERMANENT MAGNET machines SUPERCAPACITORS TORQUE control
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Calculation of Circumferential Modal Frequencies of Permanent Magnet Synchronous Motor 预览
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作者 Shenbo Yu Shuangshuang Zhong +2 位作者 Haining Zhao Pengpeng Xia Kai Guo 《哈尔滨工业大学学报:英文版》 EI CAS 2019年第1期77-87,共11页
Accurate calculation of the natural frequencies of permanent magnet synchronous motors (PMSMs) is essential to the prediction of vibration and noise of PMSMs. The analytical and numerical methods are respectively used... Accurate calculation of the natural frequencies of permanent magnet synchronous motors (PMSMs) is essential to the prediction of vibration and noise of PMSMs. The analytical and numerical methods are respectively used to calculate natural frequencies of stator yoke, stator core, stator core with windings, motor casing and stator system. It is found that the relative errors between calculated results with traditional analytical formulas and numerical results are very large. For the sake of reducing relative errors, novel analytical formulas of calculating circumferential modal frequencies of stator core, stator core with windings, motor casing and stator system are proposed. Compared with the results of numerical and experimental modal analysis, the effectiveness of novel analytical formulas is verified. 展开更多
关键词 natural frequency PERMANENT MAGNET SYNCHRONOUS motor ANALYTICAL METHOD numerical METHOD experimental METHOD
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