基于虚拟仪器功率测试分析系统

介绍基于虚拟仪器的功率测试分析系统的构成，软件设计以及数据采集、信号处理和整体结构。该系统已在实际应用中取得很好效果。     

对ERP的认识——观念的转变

试图澄清国内对ERP、管理信息系统、数据库概念间的误解。强调了ERP中的管理思想和组织的特点，给出了作者的ERP观点，指出了实现了的ERP、实现中的ERP与ERP软件的不同，强调ERP软件实际上就是一个没有企业实体、但是有自己的组织结构、规模的运作流程，可以科学管理的虚拟企业。而ERP的实施过程可以看作是将实体企业装入虚拟企业的过程。     

Ultrasonic measurement of the inter-electrode gap in electrochemical machining

During the process of electrochemical machining the dependency of the inter-electrode gap with time and process parameters can be used to determine process characteristics and to define the shape of the workpiece surface relative to the tool surface. Defining process variables to map out the required gap-time function requires the use of time-consuming iterative trials. In-line monitoring of the gap would enable process control and tool to workpiece transfer characteristics to be achieved (for ideal conditions) without the requirement to generate such parameter maps. This work explores the use of ultrasound applied as a passive, non-intrusive, in-line gap measurement system for ECM. The accuracy of this technique was confirmed through correspondence between the generated gap-time and current time data and theoretical models applicable to ideal conditions. Gap measurements are also used to demonstrate and quantify the degree of departure from ideal behaviour for an In718/chloride system as the electrolyte flow rate is reduced from 16 to 4 l min⁻¹. The monitoring of the gap size has also been shown to be effective when determining shape convergence under ideal conditions, for the example case of a 2D sinusoidal profile.     

展望21世纪的制造业及相关技术

综述了制造业未来的发展前景，重点分析了与制造业相关的制造系统、机械加工技术、生产组织形式、人员素质的发展趋势。     

影响磁式TIMS测量准确度的主要因素

测量准确度是热电离质谱 ( TIMS)的重要指标 ,对于使用年限较长的 TIMS,造成准确度下降的因素很多 ,分析判断更复杂。为了准确、系统地了解其中的主要原因 ,本文从 TIMS的基本工作原理出发 ,对影响测量准确度的主要因素 ,如离子束的角分散、能量分散、电磁场稳定性、多接收器的形变和位移、电子倍增器的衰老和放大器增益的差异等及相应的解决办法作了较深入的探讨     

Transformations in machining. Part 1. enhancement of wavelet transformation neural network (WT-NN) combination with a preprocessor

Properly selected transformation methods obtain the most significant characteristics of metal cutting data efficiently and simplify the classification. Wavelet Transformation (WT) and Neural Networks (NN) combination was used to classify the experimental cutting force data of milling operations previously. Preprocessing (PreP) of the approximation coefficients of the WT is proposed just before the classification by using the Adaptive Resonance Theory (ART2) type NNs. Genetic Algorithm (GA) was used to estimate the weights of each coefficient of the PreP. The WT-PreP-NN (ART2) combination worked at lower vigilances by creating only a few meaningful categories without any errors. The WT-NN (ART2) combination could obtain the same error rate only if very high vigilances are used and many categories are allowed.     

Material removal and surface damage in EDM of Ti3SiC2 ceramic

Material removal and surface damage of Ti₃SiC₂ ceramic during electrical discharge machining (EDM) were investigated. Melting and decomposition were found to be the main material removal mechanisms during the machining process. Material removal rate was enhanced acceleratively with increasing discharge current, i_e, working voltage, u_i, but increased deceleratively with pulse duration, t_e. Microcracks in the surface and loose grains in the subsurface resulted from thermal shock were confirmed, and the surface damage in Ti₃SiC₂ ceramic led to a degradation of both strength and reliability.     

Optimization of anodic oxidation and Cu–Cr oxide catalyst preparation on structured aluminum plates processed by electro discharge machining

This paper describes the optimization of three processes applied in fabrication of a microstructured reactor for complete oxidation of volatile organic compounds. The first process involves the optimization of the electro discharge machining (EDM) method to produce a set of microchannels with a high length to diameter ratio of 100, with a standard deviation from the average diameter below 0.2%, and with a surface roughness not higher than 2.0 μm. To satisfy these criteria, fabrication of microchannels must be carried out with two machining passes in the Al51st alloy. Then, the effect of several parameters on the anodization current efficiency with respect to oxide formation was studied. The best process conditions to get a 30 μm porous alumina layer in a 0.4 M oxalic acid electrolyte, were found to be a temperature of 1 °C, an anodic current density of 5 mA/cm², and 23 h oxidation time. At last, the resulting coatings were impregnated with an aqueous solution of copper dichromate followed by drying and calcination at 450 °C to produce active catalysts. The effect of a copper dichromate concentration, number of impregnation cycles (1 or 2), and different after-treatments on catalytic activity and stability in complete oxidation of n-butane were studied. The catalytic activity of the obtained coatings is superior to that of alumina supported pelletized catalysts even at much lower loadings of active metals.     

Frames of Reference in Mobile Augmented Reality Displays.

In 3 experiments, the authors investigated spatial updating in augmented reality environments. Participants learned locations of virtual objects on the physical floor. They were turned to appropriate facing directions while blindfolded before making pointing judgments (e.g., "Imagine you are facing X. Point to Y"). Experiments manipulated the angular difference between the learning heading and the imagined heading and between the actual heading and the imagined heading. The effect of actual-imagined on pointing latency was observed for naive users but not for users with brief training or instructions concerning the fact that objects can move with body movements. The results indicated that naive users used an environment-stabilized reference frame to access information arrays, but with experience and instruction the nature of the representation changed from an environment stabilized to a body stabilized reference frame. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

面向技术创新机遇组建虚拟企业与兼并行为的比较分析

以技术创新机遇为例分析了核心企业选择实现市场机遇的战略模式的决策过程，并给出核心企业选择实现市场机遇的战略模式的决策模型。在模型中考虑了核心企业组建虚拟企业的一个重要目的就是快速地实现市场机遇，因此在提出的决策模型中引入了时间因素。研究结果表明，当市场机遇生命周期较长时，核心企业采取兼并策略优于组建虚拟企业，反之组建虚拟企业更有利。最后提出采用期权定价模型来判断组建虚拟企业的价值，并举例说明。