A modular designed ultra-high-vacuum spin-polarized scanning tunneling microscope with controllable magnetic fields for investigating epitaxial thin films

A room-temperature ultra-high-vacuum scanning tunneling microscope for in situ scanning freshly grown epitaxial films has been developed. The core unit of the microscope, which consists of critical components including scanner and approach motors, is modular designed. This enables easy adaptation of the same microscope units to new growth systems with different sample-transfer geometries. Furthermore the core unit is designed to be fully compatible with cryogenic temperatures and high magnetic field operations. A double-stage spring suspension system with eddy current damping has been implemented to achieve ≤5 pm z stability in a noisy environment and in the presence of an interconnected growth chamber. Both tips and samples can be quickly exchanged in situ; also a tunable external magnetic field can be introduced using a transferable permanent magnet shuttle. This allows spin-polarized tunneling with magnetically coated tips. The performance of this microscope is demonstrated by atomic-resolution imaging of surface reconstructions on wide band-gap GaN surfaces and spin-resolved experiments on antiferromagnetic Mn(3)N(2)(010) surfaces.     

A solderability inspection system

The solderability in leads for electronics components is currently visually inspected only on the basis of the inspector's perception of the percentage of the lead's surface which is covered by solder. The subjectivity of this inspection criteria makes the consistency and reliability of the inspection questionable. The application of computer vision for the evaluation of solderability as an alternative to the current inspection method is presented in this paper. The proposed microcomputer-based vision system along with the computer vision algorithms are described. The testing of the system indicates that computer vision techniques are technically and economically feasible for solderability inspection.     

A feature-extraction-based process-planning system

This paper presents an automatic features-extraction and process-planning system using the STEP AP214 file as neutral design data format. A framework is proposed to support integration of CAPP with CAD system. After analyzing the STEP AP214 file, a method for extracting the basic features of part from STEP AP214 of 3D model is proposed. The combination rules of basic features are then studied by identifying feature relationships. Also, an approach to processing tolerance information is proposed by utilizing the CAD system’s self-provided functions of macro recording and editing. Finally, based on the proposed approach, the FEB process-planning system prototype was developed employing the knowledge-based approach and an example is presented to illustrate demonstrate and verify the system.     

A continuous tolerance system

This paper analyzes the current ISO tolerance systems (ISO 286-1¹ and ISO 286-22) and presents new formulas that allow the aggregation of the tolerance system in a simple way. The approach used makes it possible to compute the tolerances in a continuous manner with respect to both dimension and grade of tolerance (quality). The results are always within the tolerances tabulated in the ISO 286-1' and 286-22 Standards. This continuous approach is suitable for optimization in design and automation in tolerancing on computer-assisted design (CAD) systems. The paper proposes a tolerancing approach closer to the modern tolerancing philosophy as given by the Taguchi methods.     

一种新型的水力发电系统在线监测系统

本文采用了OPC技术与SOAP/WebSer-vice相结合的方法对水力发电系统进行远程监测与故障诊断,成功地将可编程控制器用于大型水力发电系统,对水力发电系统的现代化应用有着十分重要的意义。利用可编程控制器不但可以控制水力发电系统的运行,而且还可以对水力发电系统进行在线监测或定期监测,因此,带有可编程控制器的大型水力发电系统功能齐全,运行可靠。     

即插即用的分布式云端视频处理系统

近年来数字视频数据不断增加,如何用云计算来辅助视频数据处理成为一个迫在眉睫的问题。本文以开发平台服务为基础,构建了一套分布式视频流处理系统,可通过云端化的程序及流程,将现有视频处理模块整合到云端平台上,以进行有效率的并行化运算。实验结果表明,我们所构建的云端化视频处理系统其执行效率较高。     

洁净压缩空气系统

对洁净压缩空气系统的主要组成部件进行了介绍，对低露点系统有关气动元件的组合特点作了说明，对低发尘系统气动元件的匹配技术作了阐述。并在此基础上介绍了能稳定的供给低露点和低发尘的洁净压缩空气的气动系统。     

基于网络的制造服务系统

全球化战略是现代企业发展的必然趋势,应用Internet技术实施在分布式设计和制造下的信息交流问题是实施这一战略目标的关键问题。本文对实施网络化制造所涉及的关键支撑技术、功能模块进行了研究,在此基础上建立了适合于网络化制造服务系统的体系和工作流程。     

A measurement system for YTO

Yttrium iron garnet（YIG） tuned oscillator （YTO）,which is widely used in signal source,is difficult to be measured manually for its numerous parameters.In order to accomplish the measurement of YTO quickly and automatically,this paper gives the design of an auto-measurement system based on genernal purpose interface bus （GPIB）.     

一种特殊的行车称重系统

本文介绍了一种特殊的行车称重系统,包括其组成、原理、以及安装方法.     

A high precision straight-motion system

In this system, a steel block is completely floated by air pads mounted on a mechanical sliding table. When the table moves, the vertical and horizontal positions and the pitch, roll and yaw angles of the block change because of the misalignment of the sliding table. These changes are detected against references by optical and electronic devices and the positions and angels of the block controlled by changing the supply pressure to each pad. Straight-edge masters and a laser straightness interferometer are used as the references for vertical and horizontal straightnesses, and autocollimators are used to detect the change in pitch and yaw angle attitudes. As a reference to the roll angle attitude, the two straight-edge masters are used. The working length of the system is 1 m. The positional errors of the block motion with respect to the references are less than 0.1 and 0.4 μm and the angular changes are less than 0.2 s of arc.     

A neural information retrieval system

Group technology is an approach to manufacturing that attempts to enhance production efficiency by grouping similar activities and tasks together. The results of this process are then used in the execution of similar tasks and activities. This concept can be applied to a variety of activities such as design retrieval, purchasing, sales, and process planning [1]. Traditionally, classification and coding has been used to implement group technology. In this paper, however, we discuss a novel approach using neural networks, a technology noted for its powerful pattern-matching capability. Although this approach can be applied to the entire spectrum of group technology applications, we focus on an application to the retrieval and reuse of engineering part designs.Neural networks based on adaptive resonance theory (ART) are being developed for application in the retrieval and reuse of engineering designs. Two-dimensional representations of engineering designs are input to ART-1 neural networks to produce groups or clusters of similar parts. These representations, in their basic form, amount to bit maps of the design, and can become very large when the design is represented in high resolution. We describe a neural information retrieval system (NIRS) under development. This system demonstrates the feasibility of training an ART-1 network to first cluster designs into families, and then to recall a family of similar parts when queried with a new part design. This application is of large practical value to industry because it aids in the identification, retrieval, and reuse of engineering designs.     

A three-dimensional non-contact measurement system

A simple three-dimensional (3D) non-contact measurement system was proposed which consisted of a 1D laser displacement sensor and a servo control coordinate system. The laser sensor was installed on theZ-axis perpendicular to theX, Y-holding table. A filter was designed to remove the noise in the measured data. An extraction technique of characteristic points was proposed to catch the edge data points of the measured objects. Then the Hough-transform technique of image processing was employed to calculate the position and dimension of the edge of measured objects based on the extracted characteristic points. The experimental results show that this simple structure can effectively measure the position and dimension of 3D objects with reasonable accuracy.     

A simple electron-beam lithography system

A large number of applications of electron-beam lithography (EBL) systems in nanotechnology have been demonstrated in recent years. In this paper we present a simple and general-purpose EBL system constructed by insertion of an electrostatic deflector plate system at the electron-beam exit of the column of a scanning electron microscope (SEM). The system can easily be mounted on most standard SEM systems. The tested setup allows an area of up to about 50 x 50 microm to be scanned, if the upper limit for acceptable reduction of the SEM resolution is set to 10 nm. We demonstrate how the EBL system can be used to write three-dimensional nanostructures by electron-beam deposition.     

A control strategy for electro-magneto-mechanical system based on virtual system model

A new approach to the control of electro-magneto-mechanical system is proposed in this paper. Conventionally, these systems are controlled based on the Maxwell system model via an on-off or PID control technique, which displays acceptable performance in the low frequency region, but not in the high frequency region where position control performance is greatly degraded. In order to improve the performance, a newly developed virtual 2^nd order system modeling technique, SSID, is adopted for a complex electro-magnetomechanical system in the study. This technique states that any unknown system exposed to a random disturbance with unknown intensity can be identified in terms of a virtual 2^nd order system model via the inverse process of a certain stochastic analysis. As a typical hybrid system, a solenoid valve is used as the target electro-magneto-mechanical system to study the modeling of the virtual 2^nd order system. In order to confirm the performance of the proposed control strategy, autotuning PID controller in PWM mode is utilized. Simulations based on the conventional Maxwell system model with control via the bang-bang, autotuning PID, and the proposed virtual 2^nd order system model approaches are conducted using MATLAB Simulink. Performance of these three systems in the low and high frequency bands is also compared. The simulation results reveal that the control performance of the virtual 2^nd order system model is much improved compared with that of the Maxwell system model under autotuning PID and bang-bang controls in both low and high frequency regions, where the error is drastically reduced to approximately 1/5 of the original value.     

因特摩(INTEMOR)系统综述

该文从因特摩系统的现状、结构、功能及特点和应用前景几个方面对INTEMOR系统进行了相对全面的介绍。     

基于AHP—CBR的质量决策系统

与汽车制造企业的开发和制造过程实际相结合,根据车身常见质量问题的特点提出了一种新的相似性推理模型.该模型使用改进的AHP法来获取专家的领域知识并给案例属性赋权,用最近临法检索类似案例,有效的克服了传统相似性算法的缺点,结果更加贴近工程实际.最后基于此模型开发了车身质量问题决策系统.     

A grid-based agile process preparation system

Manufacturing enterprises are now facing serious challenges that have been evident and moreover closely associated with the dynamics of globalization. After analyzing the features of process preparation and grid technology, a grid-based agile process preparation system is presented. Firstly, the concept of digitization agile process preparation is put forward and a proposed framework to support DAPPS is followed. Secondly, with grid technology introduced into process preparation research, a six-layer agile process preparation system grid (APPSG) is constructed. Thirdly, by studying the mapping between tasks and workflow the application process of APPSG is derived. Finally, the application steps are illustrated by an example. The research in this paper, however, is beneficial to the application of manufacturing grid and information sharing of national defense industry.