Development of High-Speed On–Off Valves and Their Applications

With the widespread application of the computer and microelectronic technology in the industry, digitization becomes the inevitable developing trend of the hydraulic technology. Digitization of the hydraulic components is critical in the digital hydraulic technology. High-speed on-off valves(HSVs) which convert a train of input pulses into the fast and accurate switching between the on and off states belong to widely used basic digital hydraulic elements.In some ways, the characteristics of the ...     

Digital Factory—A Technology Show Case for Teaching and Research in Digital Maunfacturing

With the advancing digital technology and information tools in networking,the core of manufacturing activities has shifted from the physical production of goods to the systematic processing of knowledge.Teh competitiveness of tomorrow‘s manufacturing enterprise lies in the operation of such digital factory in parallel with the physical one.This change in manufactring in the digital age is taking place not only in Hong Kong but worldwide,This paper describes the development of establishing a digital factory laboratory in the Department of Industial and Systems Engineeing of The Hong Kong Polytechnic University.The Digital Factory is a focus for teaching ,research and technology transfer in the area of digital manufacturing,The paper also describes an application case of vitual manufacturing in whic computer simulation models of a production line of an AC motor are developed for investigation.     

The Design of Digital Servo-Position Control System Based on LM629

<正>The paper is concerned with the digital design of the system of servo-position control for medium-low power DC motor.The paper will be focused on the digitization design of the system.Principle of PWM will be given first in this paper.According to the theory of PWM rules and the knowledge of computer control technology,the paper will design the digital servo-position system that has a good characteristic of stability and dynamic response.     

基于OPNET的数字化变电站通信网络仿真建模及应用

Aiming at the simulation of communication network of digital substation,mathematical models applicable for OPNET communication simulation software were built based on the data fowanalysis of three layers of digital substation,i. e.,station layer,bay layer,and process layer; further,in order to fit into the requirements of OPNET, the communication network of digital substation was modeled from views of node,network and business,together with the OPNET configuration scheme. The results of real application of a substation in Shaoxing grid indicate the proposed model as well as the configuration metliods are correct and effective. [ABSTRACT FROM AUTHOR]     

复合型数字化液晶仪表开发思考

<正>In the development of complex digital color liquid crystal screen car combination instrument, key technologies were synthesized, such as liquid crystal display(LCD) section code liquid crystal screen, thin-film technology(TFT) color liquid crystal screen, special purpose drive integrated circuit(IC), liquid crystal screen bending and full fit technology,     

Digital Accuracy Of Domestic Radial Tire Mold Improved

Shandong Dongying Jintai Co., Ltd and Shandong Science and Engineering University jointly developed the radial tire mold digital design and precision molding processing technology, which was passed the professional appraisal.     

Digital Twin-based Quality Management Method for the Assembly Process of Aerospace Products with the Grey-Markov Model and Apriori Algorithm

The assembly process of aerospace products such as satellites and rockets has the characteristics of single-or small-batch production, a long development period, high reliability, and frequent disturbances. How to predict and avoid quality abnormalities, quickly locate their causes, and improve product assembly quality and efficiency are urgent engineering issues. As the core technology to realize the integration of virtual and physical space, digital twin(DT)technology can make full use of the ...     

Automatic measurement of the working band of a digital attenuator based on virtual instrument

To measure the working band of a digital attenuator automatically,a program based on virtual instrument was carried out,using Agilent E8362B network analyzer as its measuring tool.In the program,the attenuation values can be automatically written into Excel table to form the frequency-attenuation curve.Finally,through analyzing the attenuation in different frequency,the best working band of the digital attenuator can be determined easily,and the whole process is automated.Compared with the traditional way of changing the measured parameters manually and recording the measured data one by one,the developed method in the paper can avoid the cumbersome manual operation and its possible errors to improve the measurement accuracy and efficiency.     

Networking Intelligent Pressure Sensor Using Digital Lock-in Amplification Technology

Introducing a System-on-Chip(SoC)microcontroller(C8051F350)into a ceramic pressure sensor has resulted in the design of a networking intelligent sensor.An improved algorithm for digital phase-sensitive detection is used to perform lock-in amplification of the sensor signal.The compensation for the sensor error is realized by the detection of the sensor’s supply voltage and working temperature.The system also has the function of short/open circuit fault detection and can communicate with other digital equipment through an RS-485 communication interface.In the design,full utilization of the SoC microcontroller’s internal resource results in the simple hardware structure.Experimental results show that the error of the sensor is less than 0.5% at range ratio 1∶10.Employing the microcontroller and using lock-in amplification algorithm are an effective method for achieving an intelligent sensor of slowly-varying physical quantities,thereby improving the measuring accuracy and performance.     

The Design of A Kind of Electrical Appartus Based on FPGA

<正>This paper deisgns a new kind of electrical appartus which developed by programmable logic devices FPGA and produce 2Hz,100Hz sine and rectangular wave signals based on the direct digital frequency synthesis principle.By testing,the frequency of output signal is precise,the output waveforms are stable.Because of using FPGA,the Peripheral equipments are fewer,with design flexible,field programmable,easy debugged and small volume.     

纳米科技与仪器仪表

本文介绍了纳米科技的基本概念,针对纳米材料独特的结构和优异的性能,联系现代仪器仪表的实际情况,阐述了纳米科技在现代仪器仪表领域的应用和前景,目的在于探索高新科技如何与生产实际相结合,与广大同行共同推动仪器仪表产业的发展。     

CVD和PVD及其在工、模具上的应用

介绍了CVD和PVD的发展历史、性能特点及其在工、模具上的应用。用CVD和PVD技术可以在钢和硬质合金表面沉积高硬度的陶瓷薄膜，改善工、模具的耐磨性和耐烧蚀性，从而大大提高工、模具的使用寿命。     

MEMS研究的新进展——微型系统及其发展应用的研究

简要叙述了微电子机械系统(MEMS)研究中的多单元综合体--微型系统,包括它的种类、结构、工作原理及相关的特性。对其应用前景作了讨论,并提出了一些超前的设想     

石油化工装备与石油化工工业(下篇)

石化装备技术发展趋势 国际上石化专用设备技术发展趋势，基本是根据石化工艺技术发展的要求，对各种石化专用设备进行了反应动力学、流体力学、传质和传热机理、分离和干燥原理研究和设计计算研究。其中反应设备实现大型化、结构简单化、操作自动化、研究方法趋向综合化方向发展；换热设备的性能对石化产品质量、能量利用率以及系统的经济性和可靠性起着重要的作用，     

石油化工装备与石油化工工业(上篇)

石化工业生产用装备一般分为专用设备和通用设备。石化专用设备包括工业炉、反应设备，换热设备，塔器，储运设备和专用机械等；石化通用设备包括气体压缩机．泵、阀门等。由于石化工业生产一般是高压、高温、低温、易燃、易爆、腐蚀、有毒和连续化生产条件下，因此要求石化装备性能优良、质量可靠，经济安全，符合环保，能够满足石化安全，稳定、长周期、满负荷生产的需要。     

用辉光放电质谱法和火花源质谱法分析表征金属和半导体

辉光放电质谱（ＧＤＭＳ）和火花源质谱（ＳＳＭＳ）是进行高纯固体材料直接和全面分析的两种主要的分析技术，ＧＤＭＳ和ＳＳＭＳ各有所长，有互补性。适当运用这两种技术，综合其优势，可望在固体样品分析表征的许多应用中获得更全面的信息和更可靠的分析结果。本文介绍了ＧＤＭＳ在贵金属分析领域中的两个应用，讨论了高纯镓分离中的表面富集问题，介绍了用ＳＳＭＳ研究杂质元素分布均匀性和相关性的方法。     

Education and training of engineers and scientists in measurement and instrumentation

The paper reviews problems of education and training in measurement and instrumentation, and the work of IMEKO in this field. Among the principal topics discussed is the nature, scope and organisation of measurement and instrumentation science.     

企业经营管理与变革

阐述了我国企业管理变革的目的和存在的问题，并分析了发达国家企业管理进程所经历三个阶段的特征和表现，着重提出我国企业应不失时机地结合企业实际，按步骤认真地进行管理变革，才能确保企业持续稳定的发展。     

楼梯及地面扫拖一体机器人设计与研究

针对目前大部分扫拖机器人没有楼梯清洁功能的问题,设计了一种楼梯及地面扫拖机一体机器人.该机器人设置了3个高度可相对运动的模块,其中一侧模块采用吸尘方式实现扫地功能,另一侧模块基于中心对称的曲柄滑块机构设计完成拖地功能,中间模块基于皮带轮传动完成对两侧模块的升降功能,以实现机器人顺利攀爬楼梯.对机器人使用的电机进行计算并选型,然后采用有限元分析法对机器人的关键部件进行了强度和刚度校核,分析结果表明,所设计的机器人结构可满足使用要求.最后对该机器人进行了清洁试验,结果表明其能够平稳完成楼梯及地面扫拖任务,实现有效清洁,节约人力资源,改善生活卫生状况.