再论先进制造技术及其发展趋势

此文是《先进制造技术及其发展趋势》的深化与补充。首先,指出制造业在国家发展中所占的战略地位。接着,从三个方面十二点详细地分析了先进制造技术发展的特色与趋势:产品本身,“精”、“极”、“文”;制造过程,“绿”、“快”、“省”、“效”;制造方法,“数”、“自”、“集”、“网”、“智”,并强调上述这些方面均应基于“制造”与“机械”这两个基点之上。最后,提出了先进制造技术发展的指导思想与我国应该优先发展的方向,强调必须自主创新,必须“以人为本”。     

从e-商务到e-工厂的NW/IT变革 e-时代的10年发展

从1993年美国国防部DARPANet、能源部BITNet、国家自然科学基金会NFSNet搭桥并网,1994年解密为商用internet,到装上欧洲19国CERN开发的WWW,开展全球e-m、e-a、e-3b业务,形成“信息高速公路”上的“新经济”和“知识经济”。这“e-时代”10年发展的趋势是:“e-商务”经由e-efg落实到“透明工厂”,再发展到“e-工厂”,应证了马克思的经典论点“工具的革新是生产力中最重要的”,美国人的现代观点“硅谷是美国的工艺心脏”。     

磁控溅射制备Cr7C3多层复合镀层及其耐磨性能

Using closed field unbalanced magnetron sputtering ion plating technique, Cr₇C₃ multilayer graded composite coatings was preparated by adjusting sputtering process parameters. The microstructure of the coatings was analyzed by a X-ray diffraction. Surface and cross-sectional morphologies were observed by the transmission electron microscopy. Adhesion, hardness, and friction and wear behaviors were tested. Wear scars was observed by the optical microscope. Results indicate that the Cr₇C₃ coatings microstructrue is amorphous phase structrue, mainly consists of primary Cr₇C₃ particles, a small amount of Cr₃C₂ and others particles, and is fine, dense and uniform. The coatings has good adhesion and high hardness, good payload carrying capacity and life reliability, excellent friction coefficient and wear resistance performance, and the sliding dry friction coefficient is stabilized in the range 0.15~0.10, the wear rate is about 2.26×10^-16 m³/(N·m) in air.     

关于密封垫片压缩回复性能名词术语的探讨

密封垫片的压缩回复性是一项十分重要的性能.目前国内对＂回复＂和＂回弹＂两个概念没有很好地区别,以致普遍采用＂回弹率＂这一术语.讨论了＂回弹率＂和＂回复率＂的区别,并建议采用＂回复率＂或＂复原率＂替代＂回弹率＂.     

Modelling and forecasting industrial innovations via the transfer function S-shaped learning curve

Algorithms are derived for the four-parameter transfer function S-shaped curve, using a least-squared-error (LSE) method for an exponential function. The S-shaped curve is just one in a family of industrial dynamics learning-curve models of increasing complexity which may be used to replicate and forecast the start-up of industrial innovations.Controlled experiments are undertaken, via simulation of message and noise, to test the modelling and forecasting capabilities of the algorithms. A number of strategies are introduced to improve forecasting performance, such as boots-trapping, sequential and parallel adaptation, and alternatively adopting the simplified three-parameter S-curve model.Four examples of modelling industrial innovations via the transfer function learning curve models are presented. The paper concludes that although there is now the capability to model the general four-parameter S-curve, its applications are limited. This is because simpler (and hence less accurate) transfer function models tend to be more robust.     

Part family formation by memory association

Most of the part family formation methods are concerned with how to form the families as opposed to how to identify the families. However, a more appropriate approach would be to identify naturally occurring families since these methods are based on the production flow analysis, which uses already implemented routing data. This paper presents a new approach using the memory association of neural networks to identify naturally existing families. The developed system, Feature-Based Memory Association Network (FBMAN), operates by the exhaustive association approach which deals with the difficult problem of exceptional parts. Comparison with the results generated by other methods proves the effectiveness of FBMAN.     

Time-of-Flight Characteristics of Scintillation Counters with Fine-Mesh Photomultipliers

The characteristics of the time-of-flight system of scintillation counters with the -527 and R5505 fine-mesh-dynode photomultipliers for high-magnetic-field environment were measured. Scintillation counters with thin plastic scintillators 1, 3, and 5 mm thick were designed to operate in comparatively strong stray magnetic fields of up to several kilogauss. The measurements were carried out in beams of the U-10 proton synchrotron (Institute of Theoretical and Experimental Physics) with proton, ⁺-meson, and ^–-meson momenta of 0.63, 1.03, and 1.28 GeV/c. For counters with scintillator sizes of 1 × 20 × 154 mm (BI-408) and 3 × 20 × 200 and 5 × 20 × 200 mm (Kuraray and SCSN-81), time resolutions of 45–180 ps were obtained. The time resolution of the scintillation counters, in which scintillators 20 mm thick and -527 photomultipliers were used, was found to be 50–80 ps.     

A methodology for evaluating enterprise informatisation in Chinese manufacturing enterprises

Enterprise informatisation is an important way for Chinese manufacturing enterprises to improve their chances in competition in the global market, and the effective implementation of enterprise informatisation has become a major concern among researchers and practitioners. This paper analyses the connotations of enterprise informatisation, and presents the evaluation model of its lifecycle. We identify the hierarchy and weigh the evaluation on the basis of an evaluation model, and use a multilevel, fuzzy-evaluating method to determine the grades of enterprise informatisation. There is also an example that demonstrates the evaluation process.     

交叉簧片柔性虎克铰在静平衡仪中的应用及性能测试

通过对广义交叉簧片柔性铰链转角公式的分析,揭示了铰链刚度和仪器灵敏度之间的关系。为了避免垂直载荷的变化对铰链转动刚度的影响,设计具有恒定转动刚度的交叉簧片柔性虎克铰,并以柔性虎克铰为转动支撑单元搭建针对万向节装置不平衡力矩测量的两自由度柔性静平衡仪。通过对沿特定方向特定量不平衡力矩的测量,在0～7 000 g有效载荷范围内对仪器分别沿x轴和y轴不平衡力矩测量的同步灵敏度进行测试。结果表明,所搭建的柔性静平衡仪各轴的灵敏度约为1.1 g·mm,灵敏度基本不受仪器有效载荷变化的影响,而且仪器各轴同步测量的灵敏度基本一致。所设计具有恒定转动刚度的交叉簧片柔性虎克铰的转动性能及承载性能优良。     

An IGES pre-processor to integrate CAD and CAPP for turned components

EXCAP, is a knowledge-based process-planning system for rotational components. CADEXCAP is software which has been developed to integrate EXCAP with CAD systems via IGES (Initial Graphics Exchange Specification). CADEXCAP deciphers a full 2D model of a turned component developed on a CAD system and then via IGES it fully automatically generates a product model in a format suitable for EXCAP. CADEXCAP has a modular structure of three modules: readiges, preprocess and postprocess. The preprocess module, which is the concern of this paper, was written in FORTRAN77 to pre-process the IGES entities. The pre-processing process includes two main tasks. The first task is to extract only the necessary information from the IGES entities. The second task is to locate the entities in one coherent coordinate system, which is the model space coordinate system, using transformation matrices.     

Efficient vertex detection algorithms using the Hough transform

A recurring problem in computer image processing is the detection of curves and straight lines in a digital image. The Hough transform technique has been widely used in the field of machine vision for detecting straight lines and curves in an image. Typically, the parameters of the normal form of a straight line (p, ) are used for detecting straight lines in the image plane. In order to detect a straight line, the Hough transform method requires an extensive search on thep, -space by varying the values of from 0 to .In the present paper, three algorithms have been proposed to reduce the search on the parametric -axis of the parameter space for determining the vertices of a polygonal part. Prior to the application of these algorithms, the pixels belonging to each of the edges of the polygonal part are identified using a rule-base. In the first algorithm, the approximate -value for each of the edges is determined using regression analysis and the Hough transform is performed over a small range on either side of this angle value. In the second algorithm, a binary search on the parametric plane for each of the edges is performed. This eliminates the need to compute thep values for every increment of . The third algorithm improves on the binary search method by restricting the search to a small range of values. The proposed algorithms are valid for identifying vertices of convex, as well as non-convex, flat polygonal parts. Such a system can act as a preprocessor for inspection, feature recognition and reverse engineering of flat polygonal parts.