Study of Drive System Based on Permanent Magnet Synchronous Motor in Electric Vehicle

　　Study of Drive System Based on Permanent Magnet Synchronous Motor in Electric Vehicle
　　As the vehicles account in the world in the world increases sharply, traditional vehicles which use internal combustion engines bring us great facilitation, but at the same time, they do more damages to our environment. Electric vehicle, which takes electrical energy as its power, has quite wide foreground because of its zero-let and non-pollution. The drive motor and its control system are hard core in the power system of electric vehicle. The control system and its fuzzy control of permanent magnet synchronous motor based on DSP are researched and designed in this thesis.Permanent magnet synchronous motor applied in the electric vehicles is used as the object of study in this article, the http://www.999magnet.com/products/103-ceramic-magnets structure feature of permanent magnet synchronous motor is analysized firstly. Then the mathematical model is established by Rotor coordinate axis in foundation of vector control. Then vector control system structure drawing of permanent magnet synchronous motor is given, and the current controller and speed controller are studied in control system of permanent magnet synchronous motor. Meanwhile, the speed controller will be improved and one design based on the fuzzy PI speed controller is proposed. the fuzzy control is applied in control system of permanent magnet synchronous motor. The merit is displayed fully in the thought which the fuzzy control and the PI control combine in this design, the fuzzy control is used for realizing the macrocontrol to achieve the fast control, and the PI control is used for realizing the microcontrol to achieve the accuracy control.Permanent magnet synchronous motor control system simulation model is constructed under MATLAB/SIMULINK simulation environment, and the SVPWM vector control system is carried on the simulation. Meanwhile fuzzy PI controller application in permanent magnet synchronous motor control system is conducted the simulation research. The simulation results indieate that The fuzzy PI speed control contrasts the PI speed control, the system response speed has the remarkable enhancement, tendency and static property of the motor control system can be improved, and it is suitable for working request of the electric vehicle. At last, concrete hardware and software design of Permanent magnet synchronous motor control system are designed. the DSP2000 series chip is used in the hardware design for the motor control. The hardware circuit mainly includes: Main return route, driving circuit of IPM, the electric circuit of examination, protection circuit, accelerator and files position electric circuits and so on. In software design aspect, master routine and the interrupt service are desinged through using the C language and assembly language mix programming method, and PWM interrupt servicing module and breakdown interrupt servicing module detail flowchart are given. Simultaneously the detailed theory is made by the modulation aproach of space voltage vector, And the switch pattern is determined by the hardware. At last antijamming measures of hard and software designs have also been given simultaneously. 更多还原

Hybrid Electric Vehicle Driving Research Based on Interior Permanent Magnet Synchronous Motor

　　Hybrid Electric Vehicle Driving Research Based on Interior Permanent Magnet Synchronous Motor
　　Energy crisis and environmental deterioration are two important problems of global development.The design of low energy consumption and low emissions vehicle can abate the pressure of energy absence and improve the quality of environment.Hybrid electric vehicle(HEV) has many advantages,such as low energy consumption,low emissions,long drive distance etc.HEV has become an active research aera.So it is imperative to develop the HEV and the new motor driving control system.The structures and features of the three hybrid power systems were analyzed and compared in this paper,the serial and parallel hybrid electric vehicle(SPHEV) had been chosen.After the driving features http://www.999magnet.com/products/110-sintered-neodymium-magnets of the motors were analyzed and compared, the Interior Permanent Magnet Synchronous Machine(IPMSM) was chose as the driving motor.The engine and battery of HEV were also analyzed simply in this paper.Based on SPHEV structure and IPMSM driving motor,two IPMSM(MG1 and MG2) had been selected and the main parameters of IPMSM were designed.Some stimulations and analyses of the main work status of two IPMSMs were done.Otherwise the hardware and software of IPMSM were designed.DSP is as center control unit in the hardware platform and control system is established integrally after the software is designed.At last,in simulation software Advisor,parameters’ setting,simulation modules’ mathematical description,modules’ building had been mainly discussed.The secondary developments for the designed composite SPHEV had been done based on the Prius SPHEV in Advisor.The vehicle,generator,motor and composite power module had been shown.The simulation results had proved the feasibility of the control strategy.The analyzed results showed that One-Hundred-Kilometer Fuel Consumption and emission of the vehicle can meet the needs of vehicle development and greatly improve the energy saving and environmental protection. 更多还原

Position Control for a Permanent Magnet Linear Synchronous Motor Based on Disturbance Observer

　　Position Control for a Permanent Magnet Linear Synchronous Motor Based on Disturbance Observer
　　Linear feeding system cancels all the middle transmission links from the motor to the worktable and makes the transmission links of feeding system zero. "Zero-transmission" of feeding system has been obtained, which makes linear servo motor drive system apply widely in many aspects. But during the period that linear system moving as to all kinds of interior and exterior reasons, its parameter and exterior disturbance have large uncertainty. Owing to this uncertainty, control quality of system may decrease badly. In allusion to influence of mover mass variety disturbance, http://www.999magnet.com/products/103-ceramic-magnets outside disturbance and friction disturbance under low speed to servo system, some studies have been done and relevant schemes has been put forward.At first, based on reading many domestic and international relative literatures the improvements of linear feeding system are overviewed; the domestic and international research status of permanent magnet linear synchronous motor (PMLSM) feeding system robust control are outlined; the control schemes of PMLSM servo system are described. Secondly, based on the analyzing the basic structure and work principle of PMLSM, the vector control principle is introduced; the mathematic model of PMLSM is established; the influences of main disturbance factors of linear motor servo control system to the dynamic qualities are analyzed simply. In allusion to disturbance, a disturbance observer based on inverse dynamic equations of controlled systems is designed, the thrust is feedforward by the disturbance observer to resist disturbance outside and improve the robustness of system.
　　In allusion to mover mass variety disturbance, methods of disperse model reference adapt identification and self-tuning of position controller parameters are adopted, the current value of identifying mover mass is sent to the position controller and disturbance observer to amend parameters in the controller and update the mover mass parameter in disturbance observer. The system shows good dynamic and static performance when mover mass changes through this control strategy. In allusion to nonlinear friction which can decrease servo system track performance, the model reference adaptive system based on Coulomb friction is designed to compensation the friction on-line. The designed model reference adaptive parameter identifier is combined with the adaptive friction compensation system, the mover mass identified by the parameter identifier is used to update mover mass in the model reference adaptive control system based on Coulomb friction.Simulation results show that the position tracking precision of system and robustness are improved through the control scheme proposed in this paper, which could meet the requirement for high-precision numerical control machines. 更多还原

Power Maximization Control of Wind Generation System Using Permanent Magnet Synchronous Generator

　　Power Maximization Control of Wind Generation System Using Permanent Magnet Synchronous Generator
　　The efficient utilization of natural energy has attracted much attention recently in the context of depletion of energy sources and other environmental problems. In particular, wind power generation systems have been developed and implemented due to the renewability and cleanness of wind energy.This study deals with a variable-speed power generation system using permanent magnet synchronous generator (PMSM). In particular, a new PMSM control system is proposed for maximally efficient utilization of wind energy to assure maximum output. The relationship of current with loss of http://www.999magnet.com/products/110-sintered-neodymium-magnets PMSM is achieved by mathematical model considering the copper loss and iron loss. Based on the model, the efficiency-optimized control is presented and applied to wind generation system. The wind turbine settles down on the maximum power point tracking (MPPT) control method. The maximum available generated power is obtained by the optimum current vector control considering the converter capacity and the losses of generator.Then this paper tries to apply the sensorless control to PMSM. A novel sensorless control strategy is presented for PMSM and the validity of the strategy is confirmed by the experiment.At last, this paper summarized the system and gave the analysis and the prospect for future research about wind generation using PMSM. 更多还原

Research about Vacuum Simulation of Permanent Magnet Linear Motor、Drive Controller and the Protection

　　Research about Vacuum Simulation of Permanent Magnet Linear Motor、Drive Controller and the Protection
　　Principle, static attraction, dynamic feature of Breaker with linear motor drive is analyzed. This setup has the virtue of simple structure , reliable performance, smoothly drive, small oscillation, long motion and so on ,which can be widely used in electric switch , breaker and so on . Static flux is computered by FEM widely by now , static force of permanent magnet only used http://www.999magnet.com/products/112-neodymium-standard-state and attraction of both exited current and permanent magnet used are analyzed and computered . This section mainly analyze three structures: three kinds of structures have been analyzed with FEM. Result indicates that C structure has better electromagnetic performance . Magnetic field and force of linear synchronous motor drive are analyzed . A brief introduction and design of linear motor drive are presented . Model and control strategy of hybrid excitation linear synchronous motor is discussed, drive control system is designed and experimented, whose steady current and voltage waveform are measured . This paper have carried on a brief introduction vacuum switch permanent magnetism straight line motor-driven system’s monitor and the maintenance. The processing method has been taken when breakdown of vacuum switch permanent magnetism straight line motor-driven system occurs. At last, the advantage and disadvantage of the design are summarized ,future and spread of the research are forecasted .

tungsten, manganese, cyanide

作者:LEE JinWuk;LIM KwangSoo;YOON JungHee;RYU DaeWon;KOO

BongHo;KOH EuiKwan;HONG ChangSeop;
关键词:tungsten, manganese, cyanide, crystal structure, single-

chain magnet
单位:Department of Chemistry, Research neodymium price Institute for Natural

Sciences, Korea University, Seoul 136-713, Korea;Nano-Bio System

Research Team, Korea Basic Science Institute, Seoul 136-713,

Korea;
摘要:Reaction of unique [W(CN)6(phen)]- http://www.999magnet.com/products/142-neodymium-price with a magnetically

anisotropic Mn Schiff base yielded a WⅤ(5d)-MnⅢ(3d) bimetallic

compound with a linear chain structure. The magnetic properties

of the chain complex feature a ferrimagnetic behavior as well as

slow magnetic relaxation typical for a single-chain magnet.

作者:毕延芳,严陆光
关键词:门人:8496,日月:5273
单位:Graduate School,University of Science and Technology of

China, Beijing





,Institute of Electrical Engineering,

Academia Sinica, Beijing
摘要:<正> The force-free magnets are those in which the current

density J is everywhere parallel to the field H, i.e. J=αH,

where a is a scale function called force-free factor or

function.Therefore the Lorentz force f is equal to zero, since f=

μJ×H=0.However, from the virial theorem of mechanics it can be

verified that

force-free magnets are those

作者:毕延芳,严陆光
关键词:门人:8496,日月:5273
单位:Graduate School,University of neodymium price
http://www.999magnet.com/products/142-neodymium-price Science and Technology of

China, Beijing





,Institute of Electrical Engineering,

Academia Sinica, Beijing
摘要:<正> The force-free magnets are those in which the current

density J is everywhere parallel to the field H, i.e. J=αH,

where a is a scale function called force-free factor or

function.Therefore the Lorentz force f is equal to zero, since f=

μJ×H=0.However, from the virial theorem of mechanics it can be

verified that

INTRODUCTION The development of alloys

作者:李东升,彭会子,孙津生,张玉权,鞠克昌
关键词:金属学会:7478,金子:3505,概要:3104,讲演:3068,日本:3000,特许

:954,大会:904,公报:902,春期:820,东京:716
单位:Tianjin Metallurgical Research Institute





,Tianjin

Metallurgical Research Institute





,Tianjin Metallurgical

Research Block neodymium magnet
http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php Institute





,Tianjin Metallurgical Research

Institute





,Tianjin Metallurgical Research Institute
摘要:<正> Ⅰ. INTRODUCTION The development of alloys with

improved magnetic properties, especially with high (BH)_(max)

value has up to the present been the main topic for research of

magnet materials. Kaneko suggested that samples of Fe-Cr-Co alloy

may be swaged after field treatment so that the precipitated

particles from supersaturated solution would be elongated and

aligned more perfectly. The magnetic values may be raised by this

treatment, but the samples obtained by such process can only be

in the form of small bars, and moreover, the process is too

complex to be used for production in quantity.

epartment of Physics, Nanjing University

作者:赵骥万,王广厚,张健,王桂琴,张世远,刘长清,翟宏如,陈培林,宋后定
关键词:穆斯堡尔谱:4865,计算机分析:3841,南京大学:3769,科研组:3086,

日纽:2934,大学学报:2754,衬比:2616,合一:2458,比价:2326,光明:1824
单位:Department of Physics, magnetic materials
http://www.999magnet.com Nanjing University





,Department

of Physics, Nanjing University





,Department of Physics,

Nanjing University





,Department of Physics, Nanjing

University





,Department of Physics, Nanjing University





,

Department of Physics, Nanjing University





,Department of

Physics, Nanjing University





,Research Institute of Applied

Magnetics of Southwest China





,Research Institute of Applied

Magnetics of Southwest China
摘要:<正> Rare earth cobalt permanent magnetic alloys are a new

generations of permanent magnets developed in the last decade, of

which SmCo_5 permanent magnets are the best developed and have so

far been the most widely used Re-Tin material. Its magnetization

reversal mechanism is nucleation. The magnetization reversal

undergoes several proceases such as nucleation, growing,

detaching and pinning at grain boundaries, etc. For sintered

magnet, in order to attain high coercive force, not only high

nuclea-

作者:何国柱;
关键词:洁牙:6789,广厅:4385,合肥:3641,多梦:3067,切口:2631,国名:2254
单位: Nankai University,
摘要:<正> Ⅰ. INTRODUCTION The problem of focusing electron beams by periodic magnetic fields has been studied by many Neodymium Magnets
http://www.999magnet.com/products/110-sintered-neodymium-magnets authors, e.g., Brewer, Clogston and Heffner, and Mendel, Quate and Yocum. In their studies, it has been assumed that the electron beams are emerging from cathodes completely shielded from the magnetic field. Chang and Mendel have extended these studies to cover the


作者:袁重华,潘崇言,金瑞湘,吴灵葳
关键词:知心:6355,八国:5829,护国:5062
单位:Research Institute of Iron and Steel, Ministry of Metallurgy









,Research Institute of Iron and Steel, Ministry of Metallurgy









,Research Institute of Iron and Steel, Ministry of Metallurgy









,Research Institute of Iron and Steel, Ministry of Metallurgy
摘要:<正> X-ray diffraction study, together with magnetic measurements, was made on liquidphase sintered permanent magnets of the RCo_5 type (R=Sin, Sm_(0.5) Pr(0.5), or MM(0.6) Sm(0.5)). It was found that the sintered samples invariably possessed a skin layer of about 0.3 mm in thickness. This layer and the core of the sample, therefore, had te be studied separately, magnetic measurements being made only on the core. In comparison with the core, the skin layer proved to have a more complex structure. As far as composition is concerned, the akin material had a higher R-content and a lower Co-content. At an overall Co-content of about 63% by weight: the sintered core had a maximum intrinsic coercive force and exibited only a single metallic phase, i.e., the RCo_5-type intermetallic compound with CaZn_5 structure. No evidence for the presence of any R_2Co_7 or R_2Co_17 phase was detected in the diffraction patterns. The relative amount of the liquid-phase siniering aid in the mixed powder before sintering was varie


关键词:NdFeB;;rare earth permanent magnet;;microstructure
摘要:<正> An addition of Nb up to 2 at.-% into(Nd,Dy)-(Fe,Co)-B alloy causes the formation ofdendrite Fe_2Nb and the precipitates in hard magnetic grains.Both increases withincreasing Nb content.During sintering,part of Fe_2Nb dissolves within the 2:14:1 grains,and the Fe_2Nb along grain boundaries hinders the growth of 2:14:1 grains.During an-nealing,the dissolved Nb in(?)-phase precipitates out,and this nearby the grain boundarydiffuses into Nd-rich phase to form new granular Fe_2Nb and to increase the Nb contentin Nd-rich phase,this results in a precipitate-free zone in the(?)-grain near Nd-rich phase.

Nd-Fe-B magnet

作者:黄钢祥;徐庆镇;高惠民;余善富;华宏慈;王葛亚;
关键词:coercivity;;Nd-Fe-B magnet
单位:Shanghai Iron and Steel Research Institute Shanghai,200940,China.,Shanghai Iron and Steel Research Institute,Shanghai,200940,China.,Shanghai Iron and Steel Research Institute,Shanghai,200940,China.,magnetic materials
http://www.999magnet.com Shanghai Iron and Steel Research Institute,Shanghai,200940,China.,Shanghai Institute of Metallurgy,Academia Sinica,Shanghai,200050,China.,Shanghai Institute of Metallurgy,Academia Sinica,Shanghai,200050,China.,
摘要:<正> The microstructures of melt-spun Nd_135-Fe_81.74B4.76 ribbons have been investigated bymeans of X-ray diffraction,Mossbauerspectroscopy and HREM.Experimental resultsshow that optimal magnetic properties of the bond-ed magnet can be obtained by melt-spun alloys atwheel velocity of 24m/s,the microstructure ofwhich was single phase Nd_2Fe_(14)B crystallites,andno other phases,such as Nd-rich,B-rich or x-Fephase,were present.It is considered that the highintrinsic coercivity ~iH_c can be attributed to the sin-gle-domain behaviour of Nd_2Fe_(14)B crystallitephase.

Rare earth-iron-nitride;;Permanent magnet

作者:杨俊;周寿增;张茂才;马德青;李佛标;王润;
关键词:Rare earth-iron-nitride;;Permanent magnet;;Stability
单位:Department of Materials University of Science and Technology Beijing,Bering 100083,China,Department of Materials,University of Science and Technology Beijing,Bering 100083,China,Department neodymium prices
http://www.999magnet.com/products/142-neodymium-prices of Materials,University of Science and Technology Beijing,Bering 100083,China,Department of Materials,University of Science and Technology Beijing,Bering 100083,China,Department of Materials,University of Science and Technology Beijing,Bering 100083,China,Department of Materials,University of Science and Technology Beijing,Bering 100083,China,
摘要:<正> The effects of the partial substitution of element M(M=Cr,V,Mn,x=0.05;Zr,Ga,x=0.017;Si,x=0.15;Co,x=0.10)for Fe in samarium-iron-nitride Sm_2(Fe_(1-x)M_x)_(17)N_y compounds on their stabilitiesand Curie temperatures have been studied.It is found that Co,Ga can raise the Curie temperature of thecompounds.The initial decomposition temperatures cannot be raised significantly by all the studied elementsexcept Co.The result contradicts the formation enthalpy consideration.The final decomposition tempera-tures can be raised by all of the substitution elements.The effects of atmospheres on their decomposition be-havior were also studied.The results show that oxidation is the major reason for magnetic deterioration ofthe powder heated in air.Compared with nitrogen atmosphere,argon or vacuum helps to delay the decompo-sition of the compounds.

Magnetic properties;;Sintered magnets

作者:刘金芳;罗河烈;潘树明;聂向富;侯登录;
关键词:Magnetic properties;;Sintered magnets
单位:Magnetism Laboratory Institute of Physics,Chinese Academy of Sciences,Beijing 100080,China,Magnetism Laboratory,Institute of Physics,Chinese Academy of Sciences,Beijing 100080,China,General Research Institute for Non-Ferrous Metals,Beijing,China,Department of Block neodymium magnet
http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php Physics,Hebei Normal University,Shijiazhuang City,Hebei Province,China,Department of Physics,Hebei Normal University,Shijiazhuang City,Hebei Province,China,
摘要:<正> The magnetic properties of Nd_(16)Fe_(77)B_7 and Nd_(16)Fe_((61-x))Co_(16)Ga_xB_7(x=0,1,2,4,7)have been measured.Itis found that the remanent magnetization(Br),maximum energy product(BH)_(max)and the Curie temperature(T_c)decrease with the increase of Ga content.The coercive force(He)increases with the increase of Ga contentwhen x is less than 2,but decreases when x>2.At x=2,the coercive force reaches its maximum value.It is alsofound in all the samples investigated that there is a linear relationship between H_c~(1/2)and T~(2/3),which can not beexplained by Gaunt's wall barrier model.The temperature dependence of the calculated values of H_v and(4bf)has been discussed.

Department of Rare Earth Alloy Materials

作者:黄付贵;李东;吕其春;
关键词:日息:8496,巴山:5273
单位:Department of Rare Earth Alloy Materials Iron & Steel Research Institute,Guangzhou 510640,China,Central Iron & Steel Research Institute,Beijing,Central Iron & neodymium prices
http://www.999magnet.com/products/142-neodymium-prices Steel Research Institute,Beijing,
摘要:<正> The process of the epoxy-bonded Sm_2TM_(17) magnets includes:(1)after melting,the ingots are treatedby solid soluiion,and then aged and pulverized;(2)the obtained alloy powder is mixed with epoxy resin bind-er;(3)the mixture is pressed in a magnetic field;(4)the compacts are cured.When theSmCo_(4.9)Fe_(2.7)Cu_(0.54)Zr_(0.13) alloy is heat treated and pressed with optimum pressing parameters,the high qualitybonded magnets with B_r=8250 G,_iH_c=13000 Oe,and(BH)_(max)=16MGOe can be obtained.The stabilityof the magnets is studied also.The irreversible loss of O.C.(open circuit)remanence B_r in the temperaturerange between 25 and 150℃,is less than 4%.The average temperature coefficient at temperatures between 25and 70℃ is-0.03%/℃.The magnets obtained have heat resistance up to 130℃ even in long-term service,and have good corrosion resistance in acid,alkali and salt solutions.

Magnetization and demagnetization cur

关键词:花毛:10000
摘要:<正> Magnetization and demagnetization curves and hysteresis loops applied different magnetizing.fields magnetic materials
http://www.999magnet.com insintered Nd-Fe-B and Nd-Dy-Fe-B magnets from thermally demagnetized and dc field-demagnetizedstates were investigated at temperatures of up to 150℃.The first-quadrant remagnetization curves and thecurves of coercive forces _MH_C versus rernagnetizing fietds H_m from dc field-demagnetized state at roomtemperature show a step around magnetizing field as absolute value of the maximum intrinsic coercivity.Thesteps of _MH_C-H_m curves shifted to lower remagnetizing fields and the shapes of magnetization curveschanged from step type to precipitous type when temperature went up to 100～150℃ or after the specimenwas thermally demagnetized at a temperature higher than the Curie temperature.The steep rise of kneecoereivity with increasing magnetizing field is behind that of _MH_C.Note that the magnetic hardening insintered Nd-Fe-B magnets is controlled by pinning of domain walls.

metal materials; crystal growth; microstructures; laser rapid

作者:潘晶,刘新才
关键词:metal materials; crystal growth; microstructures; laser rapid solidification; magnetic materials; neodymium compounds; magnetic domains;rare earths
单位:Department of Physics, Faculty of Sciences, Ningbo University, Ningbo 315211, China








,Department of Physics, Faculty of Neodymium Magnets
http://www.999magnet.com/products/110-sintered-neodymium-magnets Sciences, Ningbo University, Ningbo 315211, China
摘要:To research the solidification behavior and microstructures of a laser remelting/solidification layer on anisotropic Nd_(15)Fe_(77)B_(8 )sintered magnets with their magnetization direction parallel to X, Y, Z-axis respectively, their surfaces (parallel to XOY plane) were scanned by 5 kW Roffin-Sinar 850 type of CO_(2) laser along Y axis. The rapid solidification of the molten alloy in the layer results in three distinct zones. The transition zone close to the unmolten portion of a magnet (substrate), consists of the columnar Nd_(2)Fe_(14)B phase (matrix), the 10.0%~15.1% dendrite primary iron phase dispersing in the matrix, and the Nd-rich phase along Nd_(2)Fe_(14)B grain boundaries. The columnar crystal zone in the middle of the layer consists of the long columnar Nd_(2)Fe_(14)B grains and their grain boundary Nd-rich phase. And the dendrite crystal zone near the free surface of the layer consists of dendrite Nd_(2)Fe_(14)B grains and their grain boundary Nd-rich phase. When the laser scanning velocity is lower, the growing direction of the microstructures in the layer tends to the laser scanning direction step by step. When the velocity is not lower than 25 mm·s~(-1), the laser remelting/solidification layer thins and the columnar crystal zone comprises almost the whole layer. Under this condition, on the substrate with its magnetization direction along X or Y-axis respectively, the columnar Nd_(2)Fe_(14)B grains in the layer grow in the direction of Z-axis (that is their long-axis along Z-axis), their alignment of the easy magnetization axis [001] is parallel to the magnetization direction of the substrate correspondingly; but on the substrate with its magnetization direction along Z-axis, the columnar Nd_(2)Fe_(14)B grains in the transition zone grow at an angle of 30°~50° between Z-axis and their long-axis. And the columnar Nd_(2)Fe_(14)B grains in the columnar crystal zone gradually tend to the Z-axis,and their easy magnetization axis [001] arrange in the range of 0°~360° of the plane perpendicular to their long-axis.

作者:连利仙,刘颖,高升吉,涂铭旌
关键词:metal materials; Zirconium; nanocomposite magnets; microstructure; magnetic properties; rare earths
单位:College of Materials Neodymium Magnets
http://www.999magnet.com/products/110-sintered-neodymium-magnets Science & Engineering, Sichuan University, Chengdu 610065,China








,College of Materials Science & Engineering, Sichuan University, Chengdu 610065,China








,College of Materials Science & Engineering, Sichuan University, Chengdu 610065,China








,College of Materials Science & Engineering, Sichuan University, Chengdu 610065,China
摘要:Five kinds of bonded magnets with compositions of Nd_(10.5)Fe_(78.4-x)Co_5Zr_xB_(6.1)(atom percentage x=0,1.0,(1.5),2.0,2.5)were prepared by rapid quenching, post heat treatment and mould-pressing.The microstructure and crystallization behavior were studied by X-ray diffraction (XRD), differential thermal analysis (DTA) and atomic force microscopy (AFM). The results suggest that high content of Zr can increase the glass formation ability (GFA) of alloys. When the content of Zr is controlled at a certain level, Fe_2Zr with high melting point is formed in the alloys, and grain size is reduced consequently. At the same time, because of Zr addition, the coercivity and squareness of demagnetization loop are obviously improved, and the energy product is accordingly increased. As a result, optimal magnetic properties of Nd_(10.5)Fe_(78.4-x)Co_5Zr_xB_(6.1)(B_r=0.659 T,H_(cj)=628 kA·m~(-1),H_(cb)=419 kA·m~(-1),(BH)_m=73 kJ·m~(-3)) are obtained when x=2.

Penning trap,linear programming,magnet design,nonlinear

作者:吴巍;何源;马力祯;黄文学;夏佳文;
关键词:Penning trap,linear programming,magnet design,nonlinear

optimization methods,pattern search
单位:Institute of Modern Physics,Ball Neodymium Magnets
http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php Chinese Academy of

Sciences;Graduate University of Chinese Academy of Sciences;
摘要:A Penning trap system called Lanzhou Penning Trap(LPT) is

now being developed for precise mass measurements at the

Institute of Modern Physics(IMP).One of the key components is a 7

T actively shielded superconducting magnet with a clear warm bore

of 156 mm.The required field homogeneity is 3 × 10-7 over two 1

cubic centimeter volumes lying 220 mm apart along the magnet

axis.We introduce a two-step method which combines linear

programming and a nonlinear optimization algorithm for designing

the multi-section superconducting magnet.This method is fast and

flexible for handling arbitrary shaped homogeneous volumes and

coils.With the help of this method an optimal design for the LPT

superconducting magnet has been obtained.

nanocomposite;ttrium substitution;glass forming

作者:龙风;施毅;刘方;倪志鹏;
关键词:quench detection,quench protection,balancing-bridge
单位:Institute of Plasma Physics,Chinese Academy of Sciences;
摘要:A NbTi 7 T superconducting magnet with a 338 mm bore system

was rebuilt and the first experiment was carried out in

Jan.2009.The balancing-bridge method used for the quench

detection system is analyzed and an improvement of the principle

of balancing-bridge conformation is given.The inductances of the

coils are calculated to estimate the proportion of the bridge

arms.The appropriate parameters are selected for the balancing-

bridge.


作者:陈治安;罗骥;隋延力;郭志猛;
关键词:nanocomposite;ttrium substitution;glass forming y

ability;residual amorphous phase;squareness;rare earths
单位:Institute of Powder Metallurgy,Block neodymium magnet
http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php University of Science and

Technology Beijing;State Key Laboratory for Advanced Metals and

Materials,University of Science and Technology Beijing;
摘要:The phase evolution,microstructure and magnetic properties

of Nd9-xYxFe72Ti2Zr2B15(x=0,0.5,1,2) nanocomposite ribbons were

investigated.It was found that substitution of Y enhanced glass

forming ability of the over-quenched ribbons and stabilized the

amorphous phase during post annealing treatment.Appropriate

content of Y substitution effectively refined the microstructure

and enhanced the remanence of the annealed samples.The residual

amorphous intergranular phase in the annealed sample improved the

squareness of loops,resulting in enhanced maximum energy

product.The optimum annealing treatment significantly improved

magnetic properties of the Y substituted ribbons.Best magnetic

properties,Jr=0.78 T,Hci=923.4 kA/m,(BH)max=98.5 kJ/m3 were

obtained from Nd8YFe72Ti2Zr2B15 ribbon spun at Vs =4 m/s,and

annealed at 700 °C for 10 min.

sintered NdFeB magnets;multilayer ceramic

作者:A.Ali;A.Ahmad;K.M.Deen;
关键词:sintered NdFeB magnets;multilayer ceramic

coating;permeable defects;rare earths
单位:Department of Metallurgical & Materials Engineering

University of Engineering & Block neodymium magnet
http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php Technology;Department of Metallurgy

and Materials Engineering CEET,University of the Punjab;
摘要:Sintered NdFeB magnets have complex microstructure that

makes them susceptible to corrosion in active environments.The

current paper evaluated the anticorrosion characteristics of

multilayer titanium nitride ceramic coating applied through

cathodic arc physical vapour deposition(CAPVD) for protection of

sintered NdFeB permanent magnets.The performance of ceramic

coating was compared to the electrodeposited nickel coating

having a copper interlayer.Electrochemical impedance

spectroscopy(EIS) and cyclic polarization in simulated marine

environment were employed to determine the rates of coatings

degradation and passivation behaviour respectively.The coating

morphologies and surface chemistry were studied with scanning

electron microscope(SEM).X-ray diffraction(XRD) was used for

identification of component phases in the coatings and the

substrate.The results showed that the polarization resistance of

ceramic coating increased with the exposure time.The rate of

degradation of Rp for the ceramic coating had an extraordinary

negative slope followed by a stable duration,before declining

towards the coating failure.In comparison the nickel coating with

copper interlayer degraded sharply.The vapour deposited ceramic

coating was found to have permeable defects that tended to "re-

passivate" during exposure providing prolonged corrosion

protection to the NdFeB substrate.The magnetic properties were

unaffected and remained at par with the nickel coating having

copper interlayer.

Rhodotron, deflecting magnets, magnetic sector field,

作者:Farshid Tabbakh;
关键词:Rhodotron, deflecting magnets, magnetic sector field,

ANSYS11
单位:Institute of Nuclear Science and neodymium prices
http://www.999magnet.com/products/142-neodymium-prices Technology,School of

Irradiation Application,Atomic Energy Organization of Iran;
摘要:The beam trajectory in the first deflecting magnet of

"Rhodotron" TT200 has been analyzed precisely by both optical and

simulation methods. We found discrepancies between these two

methods at the order of (10-3) for the slit distance and

deflecting radius and at the order of (10-4) for the magnetic

flux density. The main goal of the paper is beam focusing,

considering the angular and momentum dispersion of the particles

for the magnet designed by ANSYS.

magnetic anisotropy; spin-orbit coupling

作者:R.Skomski;D.J.Sellmyer;
关键词:magnetic anisotropy; spin-orbit coupling; crystal-field

interaction; interstitial modification; permanent magnets; rare

earths
单位:Department of Physics and Astronomy, NCMN, University of

Nebraska;
摘要:Rare-earth intermetallics Neodymium Magnets
http://www.999magnet.com/products/110-sintered-neodymium-magnets such as Nd2Fe14B and Sm-Co are

widely used as high-performance permanent magnets, because they

combine high magnetocrystalline anisotropy with reasonable

magnetization and Curie temperature. The anisotropy is a combined

effect of spin-orbit coupling and electrostatic crystal-field

interactions. The main contribution comes from the rare-earth 4f

electrons, which are well-screened from the crystalline

environment but exhibit a strong spin-orbit coupling. In this

limit, the magnetocrystalline anisotropy has a very transparent

physical interpretation, the anisotropy energy essentially being

equal to the energy of Hund's-rules 4f ion in the crystal field.

The corresponding expression for the lowest-order uniaxial

anisotropy constant K1 is used to discuss rare-earth

substitutions, which have recently attracted renewed interest due

to shifts in the rare-earth production and demand. Specific

phenomena reviewed in this article are the enhancement of the

anisotropy of Sm2Fe17 due to interstitial nitrogen, the use of

Sm-Co magnets for high-temperature applications, and the

comparison of rare-earth single-ion anisotropy with other single

-ion and two-ion mechanisms.

Researches on Testing System for Gimbal’s Micro-torque of Steering Tube

Researches on Testing System for Gimbal’s Micro-torque of Steering Tube

 With the rapid development of modern automobile industry, people have higher requirements of its dynamics, comfort and security. Security has become the critical focus in the tendency of China’s automobile technology development. Rover750 steering tube is designed based on the concept of passive safety technology. The design of its collapsible energy-absorbing structure and deformation element in the tube with gimbal can effectively reduce impact of the steering wheel to the drivers on emergency, which makes the steering system more safe.One of performance evaluations to this new type of steering tube is to neodymium prices measure its gimbal’s micro-torque. Gimbals can move in two different planes. When measured in one plane, the gimbal must be kept stable in the other one. The traditional measurement method keeps the gimbal stable by spring hook, however, it introduces variable outside force and produces errors to the results which cannot be eliminated.Two new practical methods named Elbow Method and Magnetic Suspend Method are presented. The former one keeps the gimbal stable directly by the force sensor, which can endure a certain range of shear force and be non-sensitive to this force. Similar to Maglev Train, the other method keeps the gimbal by magnetic repulsion. Both of the methods achieve the goals and avoid the disadvantages of traditional method.The http://www.999magnet.com/products/142-neodymium-prices automatic testing system of gimbal’s micro-torque according to the Elbow Method is discussed in detail. Firstly, the mechanical characteristics of the system is described, which can move freely in three different coordinates and avoid clamp locking when measured. The testing system controls the electromotor with the core of industrial controlcomputer to realize the completely automatic testing of gimbal’s micro-torque depended on high precision force sensor, signal processing circuit, and PCL-818L data acquisition card of ISA bus. Compared with the traditional method, the testing data proves the validity and effectiveness of Elbow Method, and high precision, efficiency and powerful data operation and processing of the system. Since being put into production use, the system is always in good state and promotes the production efficiency greatly.The software is also discussed, especially on its parts of precise timing, digital data filtering, real-time curve drawing and automatic interface response in the VC programming. 更多还原

The Study of Dispersion Behavior of Barium Ferrite and Its Effect on Magnetic Properties

The Study of Dispersion Behavior of Barium Ferrite and Its Effect on Magnetic Properties

Barium ferrite is widely used in permanent magnet, magnetic recording and stealth material etc. In order to obtain good properties, the particles of barium ferrite tend to micronization. The agglomeration becomes one of the main problems which limit the application of barium ferrite. In this thesis, the dispersion behavior of barium ferrite and molding of anisotropy barium ferrite in magnetic field were studied. The results of the study are as follows:1. The interaction of barium ferrite particle in the liquid was calculated. Block neodymium magnet The result indicates that the force of Van der Waals and magnetism attraction between the particles were the most reason, which result in agglomeration of the barium ferrite particles in the liquid. The magnetism attraction was the main factor that causes the particle agglomeration when the barium ferrite particle is more that 0.5μm.2. Electrostatic dispersion of barium ferrite particles in the air was discussed. The square of the charging field intensity is inversely proportional to the critical radius of barium ferrite particle.3. The effects of dispersants and other parameters on the dispersion in the liquid were examined. The results show that the dispersion of the particle barium ferrite will get better with the increase of ball-milling time and tend to be stabilization after slurry was milled for 16h. The sodium dodecyl sulfate and polyethylene glycol compound dispersant is the best. http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php PH value also has effect on the dispersion, when slurry at pH 10, the dispersion was improved. The analysis of XRD suggested that the dispersants will not result in the change of the component of the barium ferrite.4. Molding of anisotropy barium ferrite in magnetic field was investigated. The effect of dispersion, intensity of magnetic field and temperature of sinter were discussed. The results showed that the anisotropy of barium ferrite will be better while adding dispersant in the slurry and will gain excellent anisotropy barium ferrite when 更多还原

The Design of Aerocraft Electric Anti-skid Braking Controller

The Design of Aerocraft Electric Anti-skid Braking Controller

 Aerocraft electric anti-skid braking system is an important part of multi-electric aerocraft, in which braking controller is the most important part. The traditional analog controller is replaced by the digital controller and the hydraulic actuator is replaced by the electromechanical actuator, which improves the aerocraft braking efficiency and performance greatly. According to the aerocraft electric anti-skid braking system’s project request, a practical aerocraft electric anti-skid braking controller is designed, the Ball Neodymium Magnets design of the controller hardware and software is introduced in detail and the control stragety is studied in depth.Slip ratio control variable is studied. The paper analyses the relationship between slip ratio and attachment coefficient in detail, aerocraft wheel’s force and the anti-skid braking principle. The braking controller is composed of the anti-skid controller and the motor drive controller. The two redundancy actuator is put forward, which is the structure of four brushless DC motors driving four ball screws. The structure of actuator, cross-sectional view and triple geared drive equipment is introduced, and the structure and control principle of permanent-magnet brushless DC motor is analysed. In hardware designing, TMS320F2812 and its peripheral circuit make up the velocity capturing circuit. Anti-skid controller controls slip ratio error and exports http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php braking pressure signal. In the motor drive controller, current sampling circuit, overcurrent protecting circuit, pressure adjusting circuit and signal insulating circuit are made up of TMS320F2812 and its peripheral circuit. CPLD ( EPM7128AE) is employed to deal with the brushless DC motor’s rotor postion signal in order to realize commutation. Three-phase full bridge inverting circuit is composed of gate driven IC IR2130 and its peripheral circuit to drive brushless DC motor. In software designing, C language and assembly language together is adopted to control system.The three closed loop strategy with slip ratio loop as the outer one, pressure loop as the middle one and current loop as the inner one is used. Conventional PID is still used to adjust error in control algorithm and is improved.The strategy of the fuzzy control adjusting PID is put forward. The model of the convertional PID control and the fuzzy control are based. According to the simulation curve, system response speed is quicken, over regulation measurement is 更多还原

The Research of High-quality Dual-redundancy Rudder Servo System

The Research of High-quality Dual-redundancy Rudder Servo System

 Missile rudder is the executive part of missile flying system, and is close to the attack precision of the missile.This dissertation introduces the background and significance of the research and the present situation and developing prospect of the EMA Servo. In the paper, a set of fully-digital-signal servo system for missile rudder based on DSP (TMS320F2812) is designed in accordance with magnetic materials
http://www.999magnet.com he high accuracy position servo. The structure and principle of the electric steering engine and dual-redundancy motor is also introduced. On the basis of the brief introduction of the math model of BLDCM with one winding and double windings, the dynamical mathematics model for BLDCM according to the state equation is provided, some simulation waveforms and results are acquired, meanwhile, the theoretical analysis of some system faults such as inverter switch failure, winding failure and position sensor failure is given. According to the general design, the detailed system hardware and software design is finished, the position servo’s digital control and the function of the double windings’ current balance is realized, the system possesses certain ability of redundancy management and fault tolerant.In hardware design, the construction process of the whole servo with TMS320F2812 DSP as the core controller is explained, and the key part is analyzed in detail; the CPLD control logic is designed, and the waveform by simulation based on maxplus-II is also provided. In software design, the paper discusses the integrated embedded software development environment for Texas Instrument’s TMS320 series DSP firstly, and the resources of DSP we used secondly. The main algorithm — completely-digital triple-loop control, composed by current loop, velocity loop and position loop is adopted. And the multi-mode PID control algorithm is used concretely in view of the nonlinearity and time-change nature. Especially in the current loop design, average current injection method is adopted, and the method is quite convenient to solve the current balance problem. Meanwhile, the redundancy management is facilitated. Finally, the experiment results are analyzed and it’s proved that the system possesses strong robustness and good dynamic-static performance.At the end of the paper, all factors which affect the system performance are analyzed, and optimization designs are presented. 更多还原

基于虚拟仪器的步进电机及其驱动电路检测系统

基于虚拟仪器的步进电机及其驱动电路检测系统

】 LAMOST is the abbreviation of "Large Sky Area Multi-object Optical Spectroscopic Telescope". It is one of the ongoing super national scientific projects in China. It will be one of the most powerful optical astronomical telescopes in the world when finished. According to the holistic design of LAMOST, about 4,000 fibers are needed to be positioned precisely on a focal plate of 1.75 m magnetic materials

http://www.999magnet.com in diameter. Each optical fiber positioning unit is controlled by two stepping motors. The capability and reliability of the stepping motor system is very important in the optical fiber positioning.A suit of test system based on Virtual Instruments technology is built. The multi-channel data acquisition and state analysis is realized by using the test system. These analytic results are fed back to the main controlling computer. Corresponding decision is made by the main controlling computer according to these analytic results.Virtual Instrument is a computer based instrument system which has a virtual panel and its function is realized by software. It is the production of the association between computer technique and instrumentation technique. It is based on computer system and software technique is the kernel. Virtual Instrument breaks through the limitation of the capability of traditional instrument by data acquisition, signal processing, data storage and graphic display. It is a carrier flat of the measuring and automatization system with high performance and low cost.The stepping motor’s capability and reliability is a very important factor in the control of the optical fiber positioning unit. In order to enhance the work capability of the optical fiber positioning unit, the accuracy and the rapid of the stepping motor’s movement should be improved. As a driver like the stepping motor, to enhance the two capabilities when the load is unchangeable, the torque of the step motor is the key. So we develop a suit of testing system of the torque of the stepping motor based on LabVIEW.Stimulant control and testing of the zerobits is carried out. 更多还原

某高射速自行迫击炮自动供弹机控制方案研究

某高射速自行迫击炮自动供弹机控制方案研究

 This paper is base on the research of the total research on high firing rate mortar. The control scheme and method of Double-barrel mortar’s automatic loading system were discussed in this paper. After that, the scheme used Matlab/Simulink to found the system’s model, Neodymium Magnets

http://www.999magnet.com/products/110-sintered-neodymium-magnets and connected with hardware controller by I/O interface , using Real-Time Windows Targets and Matlab-Adams simulation technology to realize semi-physical simulation.The main research and conclusion of this paper can be summarized as following:1、 Based on the virtual prototype module of Double-barrel mortar, analysed the structure, working elements and movement rules of this mortar’s auto leading system, gave the technical guide line, and studied out the control scheme of the automatic loading system.2、 According to the mechanics structure, calculated the electromotors’ parameters for next simulation step, such as power, torque, rotate speed and so on, and established the eletromotor’s type.2、 Using Matlab’s Simpowersystem and Simulink module, some simulation modules, such as Permanent Magnet Synchronous Machine and it’s drive system, pushing system’s control module was designed. And then , using the method which could unite the Adams and Matlab, the control module was connected with the Adams’ s virtual prototype module.3、 Based on the automatic loading system’s scheme, the framework of controller was established, including the design of the hardware circuit and the software of control.4、 The hardware control system was connected with the united simulation module about Matlab-Adams to realize the semi-physical simulation which was called "hardware in the loop" by using Advantech Co. Ltd ’s DAS cards. 更多还原

The Synthesis and Catalysis Research of Non-Cp Rare Earth Metal Complexes

　　The Synthesis and Catalysis Research of Non-Cp Rare Earth Metal Complexes
　　The denifition of the rare earth is that the fourteen elements of the upper row on the inner-transition metals on the periodic table that follow the element lanthanum. Some reference sources include lanthanum in this series others do not. For all of these elements the filling orbital is 4f. This series is a sub-series of the transition metals.Rare Earth has been widely used in electronic, petrochemical, metallurgy, machinery, energy, light industry, environmental protection, agriculture, and other fields. Application of Rare Earth to produce fluorescent materials, rare earth metal hydride battery materials, electric light materials, permanent magnet materials, hydrogen storage materials, catalytic materials, precision ceramic materials,Neodymium Magnets laser materials, superconducting materials, magnetostrictive material, magnetic refrigeration materials, magneto-optical storage materials, optical fiber materials.Rare Earth has become the new generation catalysts for olefins polymerization after the Ziegler-Natta catalyst.Chromium-based catalysts played a significant role in coordination polymerization of olefins.
　　The chromium catalytic systems have been largely ignored in the development of the homogeneous methylalumoxane (MAO)-activated systems that have attracted so much attention in the past decade. It is attributed to the difficulty of studying the chemistry of Cr (III) as a result of its paramagnetic nature. Recently, some of the most significant advances in rare earth metal catalyst systems have been made using precatalysts that bear an additional neutral donor, either bridged or unbridged to the Cp unit. Jolly et al. reported that half-sandwich type chromium complexes showed good activity for the polymerization of ethylene to give the polyethylene with narrow molecular weight distributions and high molecular weight. Ender et al. described cyclopentadienylchromium(III) complexes functionalized by quinoline or N, N-dimethylaniline for the polymerization of ethylene. These results revealed that nitrogen donor ligand-substituted cyclopentadienylchromium compounds could effectively catalyze the polymerizations of the olefins. However, the reports concerning oxygen donor ligand-substituted cyclopentadienyl chromium compounds are scarce.In this dissertation, a series of rare earth metal alkyl complexes based on multi -dentate N, P, O-heteroatoms containing ligands have been synthesized via alkyl el -imination. The molecular structures of the complexes are characterized by IR, NM -R spectrum and X-ray diffraction analysis.
　　The activities of these complexes http://www.999magnet.com/products/110-sintered-neodymium-magnets as ca -talysts for ring-opening polymerization (ROP) of lactide have been investigated. Conclusions are summarized as follows:1) three non-Cp ligand containing N\P heteroatoms have successfully been synthesized,and the reaction possibility of these ligands with rare earth metal tri(alkyl)complexes were investigated.A new rare earth metal bis(alkyl)complex has been obtained via protonolysis reaction between rare earth metal tris(alkyl)s and the corresponding ligand. To our initial disappointment, that arylimino-substituted bis(amino)cyclodiphosphazanes chelate lutetium as amino(imino)ph-osphoranates and not as diamides. Ligand HL4 is apparently predisposed to side-on coordination,due to theπ-delocalization in N-P-N moiety on chelation.2) The polymerization of lactide was carried out with the new rare-earth-metal bis(alkyl) complex 3 The effects of polymerization conditions on catalytic activity was investigated, such as the ratio of monomer to catalyst and the polymerization solvents etc. the complete conversion of the monomer into polylactide (PLA) were achieved within 1 magnetic materials h at 20℃. The molecular weight of the resultant PLA was close to the theoretic value with narrow molecular weight distribution.However, when the polymerization was carried out in CH2Cl2,the complete conversion of the monomer into polylactide was difficult in a long run.3)Treatment of HL5 with 1 equiv. of Ln(CH2SiMe3)3(THF)2 indeed afforded mono-alkyl bis-ligand complexes (L5)2Ln(CH2SiMe3) (4: Ln=Y,5: Ln = Lu)without alkyl migration and the formation of homoleptic counterpart. X-ray diffraction analysis revealed Complexes 4 and 5 were isostructural mono-alkyls of solvent-free stabilized by two b-ketoiminato ligands in P,N,O-tridentatemodes.4) The polymerization of the Latice were carried out with the complexes. catalytic activity of the complexes for the ring-opening polymerization(ROP) of L-lactide (L-LA) under mild conditions were higher active in toluene and THF. Complete conversions of the monomer into polylactide (PLA) were achieved within 1 h at 20℃The molecular weight of the resultant PLA was close to the theoretic value with narrow molecular weight distribution.

Influence of Magnetization Treatment on Liquid-liquid Equilibrium

　　Influence of Magnetization Treatment on Liquid-liquid Equilibrium
　　In this paper, in order to determine the influence from magnetic fields in Chinese medicine menstruum reclaims, with different magnetic flux intensity B magnetic fields, water, ethanol, butanol, butyl acetate were employed to determine the influence from magnetic fields to the matters’viscidity and surface tension, and to the liquid-liquid Neodymium Magnets balance of butanol-water system and butyl acetate-water system and ethanol-water-benzene system. It indicates that magnetic fields can decrease the intensities of ethanol, butanol, butyl acetate, and the surface tensions of water, ethanol, butanol、butyl acetate. But the intensities of water were increased. Also, the magnetic fields can change the liquid-liquid balances of butanol-water system and butyl acetate-water system with a non-linear inclination. All in all, extra magnetic fields, especially the 2# magnetic field, can augment the solubility of the two systems; the influence from magnetic fields to the http://www.999magnet.com/products/110-sintered-neodymium-magnets liquid-liquid balance of ethanol-water-benzene system mainly depends on the values of magnetic induction intensity, and the effects fluctuate with a non-linear inclination.Based on experiment data, the equation of liquid-liquid equilibrium including magnetic flux density B and the equations of viscidity and surface tension are put forward. At the same time, dependability is proved by analyzing the fitted results.In this paper, the relations between magnetic field and internal force of molecules or force between molecules are also expatiated systematically. From the point of view of mechanics, the magnetization mechanism of permanent magnetic fields on the liquid-liquid equilibrium is discussed, and the experiment phenomena are explained by it.

舵机电动加载系统建模与计算机辅助设计

　　舵机电动加载系统建模与计算机辅助设计
　　In order to test the performance of actuator system and complete the hardware in loop simulating of flying control system, the electric loading system is used to simulate dynamic air loads of actuator’s surface when the aircraft is flying. conditions. Nowadays, the electro-hydraulic servo system is the common choice. Along with the improvement of electronic neodymium prices and electrical technology, and with the development of control technique for torque motor, the electrical loading is the developing trend of the load simulator, which is the focal research in this dissertation.The electric load system for actuator uses permanent magnet motor as driving unit actuator and the pulse width modulation (PWM) control technique is used to drive the motor. The feedback signal from the torque sensor and displacement sensor is transmitted into the controller to control the motor. Due to the difference of loading actuator the control performance of the electrical load simulator differs from that of the electro-hydraulic load simulator, such as the http://www.999magnet.com/products/142-neodymium-prices stability of the electrical loads simulator, the cause of plus torque, the methods to improve the rapidity and tracing accuracy of the system, and so on.Considering the influence of the surplus torque on the precision of load system, the surplus torque’s produce in load system is analyzed in details and a simple and effective method to restrain is put forward. According to the characteristics of load system, the PID algorism is proposed. The results of Simulation have proved that output can track input accurately.Finally, the data of the experiments are analyzed and the simulation is conducted. Based on the experimental results, many practical problems are summarized, which is helpful to the development of the electrical load simulator in the future.

Intra-Articular Glucocorticosteroid Injection into Sternocostoclavicular Joints in Patients with SAPHO Syndrome

Intra-Articular Glucocorticosteroid Injection into Sternocostoclavicular Joints in Patients with SAPHO Syndrome 

 Jochen Jung , Marc Molinger , Dieter Kohn , Martin Schreiber , Michael Pfreundschuh , Gunter Assmann 

 University Saarland Medical School , Orthopedics , Kirrbergerstraße 1 , Homburg , Germany , University Saarland Medical School , Rheumatology ,magnetic materials

http://www.999magnet.com  Kirrbergerstraße 1 , Homburg , Germany , University Saarland Medical School , Radiology , Kirrbergerstraße 1 , Homburg , Germany 

Objective Painful swelling of the anterior chest wall caused by osteitis and hyperostosis in the sternocostoclavicular region are characteristically observed in patients suffering from SAPHO syndrome. Autoimmune triggering of inflammation and bacterial infection is hypothesized to be involved in the pathogenesis. Promising treatment modalities include antirheumatic and antibiotic medications. Methods Ten patients with SAPHO syndrome and symptomatic osteitis in the sternocostoclavicular region we ...re treated by a single instillation of glucocorticosteroids (20 mg triamcinolone) into the sternocostoclavicular joints. The disease activity was evaluated on the basis of a questionnaire asking for osteitis activity (quantified for complains on a scale of 0-6), by Health Assessment Questionnaire (HAQ) score, erythrocyte sedimentation rate, C-reactive protein, and magnet resonance imaging (MRI) scanning of the sternocostoclavicular region (osteitis scores quantified for inflammation on a scale of 0-2 by the radiologist) prior to injection and after 12 weeks. No changes of the preexisting antirheumatic therapy were allowed during the observation interval. Results All patients continued the study during the follow-up. The osteitis score changed from 4.2 (mean; standard error (SE) ±0.3) to 3.2 (±0.4), [ P = 0.062], the erythrocyte sedimentation rate from 19.0 (range from 12 to 30) to 19.9 (from 12 to 27), [ P = 0.430], and the MRI score from 1.6 (±0.2) to 1.5 (±0.2) [ P = 1.0]. One patient developed an increase of the clinical osteitis activity from 3 to 5 according the scoring system; only 2 patients showed a reduction of the MRI activity score from 2 to 1. Conclusions Intra-articular glucocorticosteroid instillation does not appear to reduce osteitis in the sternocostoclavicular region in patients with SAPHO syndrome.

Micromagnetic Simulation of Demagnetization Curves for Nanocrystalline NdFeB Magnets

　　Micromagnetic Simulation of Demagnetization Curves for Nanocrystalline NdFeB Magnets
　　Nanocrystalline NdFeB with excellent permanent magnet property have attracted much attention since the advent. People have study it’s quality experimentally and theoretically. In 1996, Fischer,Schrefl et al firstly performed the calculation on the demagnetization curve of Ball Neodymium Magnets Nanocrystalline Nd2Fe14B by using the micromagnetic finite-element method and three-dimensional model. However, the quality of the calculation is not goodsuch as the calculated μ0iHc for the stoichiometric composition magnets ofdifferent grain sizes are larger than the experimental values of the Nd2.33Fe14B1.06Si0.2 magnets by 60%170% .This is unreasonable. Because the intergranular exchange interaction for the magnet of stoichiometric composition with Nd2Fe14B grains in direct contact is larger than that of Nd-rich magnets with a Nd-rich paramagnetic boundary phase separating the grains.http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php The character of the Nanocrystalline NdFeB is determined by grain size and boundary phase. For the stoichiometric alloy, the adjacent Nd2Fe14B grains of the NdFeB magnet contact each other. But for the Nd rich magnet, the grains is surrounded by Nd-rich paramagnetic boundary layer. Many calculations has been performed on the demagnetization curve for stoichiometric Nanocrystalline Nd-Fe-B magnet with Nd2Fe14B grains at room temperature. While the study of the Nd-rich Nanocrystalline Nd-Fe-B is

Nondestructive Testing Method and Tools for In-Service Ferromagnetic Heat Exchanger Tubes

　　Nondestructive Testing Method and Tools for In-Service Ferromagnetic Heat Exchanger Tubes
　　Ferromagnetic heat exchanger tubes are employed commonly in industries, corrosion in tube is the main failure reason of shell and tube heat exchangers and it usually cause large economic loss. The in-service inspection of ferromagnetic tube needs special technology for the limitation of tube’s high relative permeability and structure restriction. The inspection of ferromagnetic tube is carried by imported foreign instrument, which is very expensive. So it is meaningful to take a study on the in-service inspection method of ferromagnetic tube。Two magnetic testing methods are put forward which are called magnetic flux leakage (MFL) and opened magnetic circuit based on the characteristics of ferromagnetic heat exchanger tube. Finite neodymium prices element method (FEM) by ANSYS software is used to analyze the magnetic circuit and configuration of MFL probe. How the design changes effects testing signal of the MFL assembly and the principle of opened magnetic circuit testing method in ferromagnetic heat exchanger tube inspections are also studied. The FEM analysis shows that the cross section area of the permanent magnets is the key factor of pipe magnetization. Magnet length, material and dimension of armature also effect the MFL signal. MFL and opened magnetic circuit probes are designed by the guidance of theoretical analysis. Experiments were taken by these probes. The experiment results show that it is applicable to use magnetic testing method in ferromagnetic heat exchanger tube inspection.
　　The MFL probes are able to detectφ1.6mm through hole onφ25mm×2mm tube.φ1.6mm through hole and outside crack whose depth is about 20% wall thickness onφ38mm×3mm tube are http://www.999magnet.com/products/142-neodymium-prices also detectable by MFL probes. The MFL probes are able to detectφ3.2mm through hole onφ51mm×5mm as well. According to the research results, a magnetic testing tool is designed and the MFL probe design is discussed in detail. The tool was tested in TianJin petroleum and chemical mechanism Research Institute and the inspection result shows that both of the two kinds of magnetic probes are able to detectφ2mm through hole and taper blind hole which is 20% of the pipe’s wall thickness depth. The result proves that the magnetic testing method and tool meet field demands.The experiment and application results show that the magnetic testing method and tool have advantages of high sensitivity, good stability, easy-handling and low-cost, which exhibit a bright application future.

Research on Microstructures and Properties of Microalloying Mg-Zn-Si Alloy Prepaired by Electromagnetic Stirring

　　Research on Microstructures and Properties of Microalloying Mg-Zn-Si Alloy Prepaired by Electromagnetic Stirring
　　Compared with other structural materials, magnesium alloys have many excellent properties and have been widely applied in the automobile, IT and aerospace industries. Fabrication of high performance magnesium alloys by means of electromagnetic stirring combined with alloying is an important process in commercial application in the future.In the thesis, a set of rotating permanent magnet electromagnetic stirring device has been used, which is of manipulation of temperature and magnetic field distribution and intension. The evolution process of non-dendritic structure Mg-6%Zn-2%Si slurry at nonisothermal and isothermal stirring temperature under electromagnetic neodymium standard state stirring has been investigated with the device, the results indicate that primary Mg2Si evolves firstly from fine dendrite to dendrite and becomes spherical grains at last.
　　Furthermore, effects of process parameters (e.g. rotating speed of magnet barrel, alternation of rotating direction and stirring temperature) on the microstructure of semisolid Mg-6%Zn-2%Si alloy have been also investigated, which indicate that higher rotating speed of the magnet barrel makes the morphology of primary Mg2Si more spherical, alternation of rotating direction has no obvious effect on the the microstructure of semisolid Mg-6%Zn-2%Si alloy and stirring temperature reducing in stirring progress makes the primary Mg2Si more spherical while some of the grains may combined with each other. The mechanical properties of solidified Mg-6%Zn-2%Si ingot stirred by different stirring process have been studied, the results of which showed that isothermal stirring at 670℃70 Hz 10 min and solidifying with the most http://www.999magnet.com/products/112-neodymium-standard-state high cooling rate is the optimal process.Microstructure and properties of Mg-6%Zn-2%Si alloy modified with different content of Ce-rich mish metals, Ca, and B have been investigated. It is found that the alloys modified with 0.3wt.% content Ce-rich mish metals have the best tensile stength in the same series alloy modified with same alloy element, while 0.6wt.% and 1wt.% are the optimal content to alloys containing Ca and B. Those alloys which possess highest properties were stirred with the optimal process mentioned above, it is found that electromagnetic stirring has obvious effect on the semisolid microstructure of the alloys: the primary Mg2Si is refined in the alloy which containing Ce-rich mish metals, and exist in form of short-rod and pellet in the stirred alloy containing Ca. B make the primary Mg2Si to become coarse after stirred. Tensile strength and elongation at all test temperature (20℃and 150℃) are enhanced in all the three kinds of alloys after stirred, while the hardness has no obvious progress.