射流辅件

升压器一、滑柱式双向升压器图1是它的结构示意图,其动作原理如下:当左边有控制信号时,即薄膜7压紧通道3,则气源一路从左推滑柱向右,此时气源另一路气从右2输出,滑柱右端之空气从右之6及右之4排出,完成一放大作用,如右边控制信号输入,则动作原理同上。     

基于粒子群优化的多智能体强化学习算法在水下机器人定位系统中的应用

提出一种融合多传感器的超小型远程操纵型水下机器人(ROV)快速定位系统。利用基于粒子群优化的多智能体强化学习算法融合水下机器人超短基线定位声纳及位姿传感器信号,可提高ROV的定位速度。给出ROV定位系统试验平台硬件结构以及多线程、模块化的软件系统搭建方案。在船模实验池中进行ROV的定位验证,结果表明该算法满足ROV对定位速度的要求。     

永磁同步电动机变频调速的分析

针对永磁同步电动机与鼠龙式三相异步电动机变频调速的不同特点,本研究在传统的矢量控制系统中引入了模糊PI控制方法,利用模糊控制理论控制永磁同步电动机。在Matlab/Simulink仿真软件中设计了模糊PI控制模型,通过仿真分析可知,该控制方法相比三相异步电动机能更快地建立起旋转磁场,同时动态响应快,能实时抑制超调量,因此,采用模糊PI控制方法控制永磁同步电动机更具优越性。研制了一台样机,完成电机转速给定信号、转子位置信号、电压电流信号的采集,实现转速、电流双闭环控制算法,坐标变换及三相电流参考信号、PWM信号的产生,以及系统保护、显示等任务。验证了控制永磁同步电动机时,模糊PI控制下的转矩响应相比传统PI控制下的转矩响应更平缓。     

交流伺服系统无速度传感器矢量控制研究

为保证控制精度,降低制造成本,研究了一种无速度传感器矢量控制交流伺服系统。该控制系统采用id=0矢量控制策略,PWM采用空间矢量PWM(SVPWM)技术以提高控制性能;同时设计了模型参考自适应系统(MRAS)对电机转子速度/位置进行估算,实现无速度传感器控制。数字仿真试验验证了所设计的伺服系统跟踪定位能力强,鲁棒性好,速度/位置估算精度高。     

一种移动码垛机器人视觉控制与定位

对移动码垛机器人视觉控制与定位的需求进行了研究,设计了一种摄像头支架,提出了基于DSP控制3轴联动的方案。利用TMS320F28335DSP增强型控制器的局域网通信接口e CAN模块实现上位机与DSP实时通信;选用了3个增强型脉宽调制e PWM模块,产生3路周期和频率可调的PWM波用来驱动3个电机。通过该视觉系统对目标物识别与三维定位,数据分析显示定位结果均在目标物的有效区域,表明摄像头位姿控制准确,证明了开发的摄像头控制系统可满足移动码垛机器人视觉系统的要求。     

集装箱波纹板折线焊缝跟踪的研究

为了实现类似于集装箱波纹板形式的焊缝自动焊接,采用了一种四自由度、可在波纹板折线位置处改变焊枪角度的直线轨道式焊接机器人.设计了空间漫反射激光测距传感器检测波纹板的折弯位置,利用TMS320LF2407A型DSY产生PWM脉冲信号驱动传感器芯片线阵CCD,并采集传感器输出信号,通过串行口传输到上位计算机.通过数字滤波器...     

基于多传感器的超高压输电线路巡检机器人越障控制

根据500 kV超高压架空输电线路的结构及障碍特点,设计多传感器、多驱动器巡检机器人越障控制方案,提出采用多传感器二次定位方法实现巡检机器人越障时的空间定位.阐述系统的结构和越障原理,通过线下模拟实验环境,不断测试生成合理的知识库,实际越障时根据实测信号自动调用知识库完成自主越障动作.实验结果表明:传感器工作可靠,知识库和空间定位方法设计合理,巡检机器人能高效、快速、高精度地完成巡检及越障任务.     

轮式机器人折线焊缝跟踪协调控制方法

研究了以旋转电弧作为传感器,采用轮式移动机器人对折线焊缝进行跟踪的协调控制方法.设计了自适应模糊控制器对十字滑块和车轮进行协调控制,通过控制机器人移动对焊缝进行粗略跟踪,同时调整十字滑块带动焊枪对焊缝进行精确跟踪.为了使机器人的移动方向与焊缝走向一致,采用Sugeno型模糊逻辑系统作为滤波器对机器人本体的方位角偏差进行滤波处理,使机器人本体在跟踪焊缝的直线段时做直线运动,在跟踪焊缝的曲线段时做转弯运动.结果表明,该算法能够成功应用于最大为60°的折线焊缝和Z形焊缝的自动跟踪焊接.     

基于多传感器的机器人夹取系统研究

为解决由于内置传感器较单一导致的机器人抓取动作不灵活、作业精度低等问题,提出一种基于多传感器的机器人夹取系统。首先采用扩展卡尔曼滤波算法融合机器人内置传感器所测量的位置、速度和角度等信息,实现机器人自身位姿检测。在此前提下,利用外置传感器完成对目标物的自动识别与定位。为增强信息的可靠性和系统的分辨能力,并根据输出信号对机器人夹取动作进行运动学建模,设定夹取系统的硬件、软件环境及传输电路后完成系统设计全过程。实验结果证明：所提方法设计的机器人系统能够实现对夹取目标的精确对准,运动特性明显提高,作业误差有效减小。     

基于图形界面的数控机床永磁电动机模糊控制系统的综合与分析

基于MATLAB的模糊逻辑工具箱图形界面(GUI)工具,对数控车床永磁电动机模糊控制系统进行综合与分析.模糊控制器的输入语言变量选择为速度误差以及误差的积分,输出语言变量选择为电流的给定量,这样既能实现模糊控制不依赖被控对象模型,又能发挥比例积分控制规律稳态无误差的优点.采用模糊逻辑工具箱图形界面工具进行系统的综合与分析,可以方便地修改语言变量的论域、隶属度函数和模糊控制规则,设计过程简单清晰.仿真结果表明,采用该方法设计的模糊控制系统鲁棒性强,满足高速磨床永磁电动机系统对给定速度的准确跟踪和对扰动的抑制.     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Effect of Short-Time Aging on the Pitting Corrosion Behavior of a Novel Lean Duplex Stainless Steel 2002

The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.     

Information for Contributors

正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis     

Preface

<正>We are pleased to present this Special Issue of Transactions of Nonferrous Metals Society of China containing selected papers from the First Asian Conference on Aluminum Alloys(ACAA-2013),held in Beijing,China,13–17 October 2013.This conference has been initiated,with approval of     

Information for Contributors

The Transactions of Nonferrous Metals Society of China, founded in 1991 and sponsored by The Nonferrous Metals Society of China, is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology, including mineral processing, extraction metallurgy, metallic materials and heat treatments, metal working, physical metallurgy, powder metallurgy, with the emphasis on fundamental science. It is the unique preeminent publication in English for scientists, engineers, under/post-graduates on the field of nonferrous metals industry. This journal is covered by many famous abstract/index systems and databases such as SCI Expanded, Ei Compendex Plus, 1NSPEC, CA, METADEX, AJ and JICST.