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＂.     

Identification of Characteristic Features of Envelopes of Testing Pulses with the Help of the Diade Convolution Adaptable to Noise Level: I. Identification of Types of Characteristic Features

A method has been suggested for binary coding of envelopes of measured pulses from eddy-current transducers. The method enables one to identify their characteristic features of various types, such as leading edge, trailing edge, maximum, minimum, horizontal portion, start point of leading edge, end point of leading edge, start point of trailing edge, and end point of trailing edge, using weighted sums of no more than four Hadamard-ordered Walsh functions with numbers 0, 1, 2 ^n–1, and 2 ^n–1 + 1. The paper demonstrates the existence of obvious diade correlations of coded combinations corresponding to specific fragments with both one another and distortions of a current sampling simulated by adding an error vector. These properties make possible an identification of types of characteristic features in current samplings of binary data with four levels of a noise immunity, which are selected in the process of adaptation to the noise intensity with due account of the significance of identified features.     

Magnetic-Powder Inspection of the Crystallographic Texture of Electrical Steel

A theoretical model of the formation of rhombic (in the case of an edge texture) or square (on cubic texture) indicator patterns upon magnetization of single crystals of electrical steel orthogonally to the (110) and (100) planes is described. The model is based on a solution of Maxwell's equations for a magnetostatic problem, with magnetic permeability introduced as a tensor. Two field sources are considered as limiting cases: (a) loop, short coil; (b) semi-infinite magnet, long coil. Two cases of permanent magnet diameters are considered: thin, d = 4 mm; thick, d = 20 mm. Two cases of density of magnetic charges are considered: (a) = const; (b) = ₀/ .     

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.     

A Position-Sensitive Detector for the Polarized-Neutron Spectrometer

A linear detector of thermal neutrons, developed at the Laboratory for High Energies (Joint Institute for Nuclear Research), is used in the polarized-neutron spectrometer of the -2 reactor (JINR). The data are acquired in the regime of frame-by-frame survey to select neutrons with a wavelength = 1–12 Å by the time of flight. The neutron-detection efficiency is 70% for a wavelength of 2 Å. The detector exhibits a low sensitivity to -rays, a differential nonlinearity of 1.5%, and a spatial resolution of 1.5 mm at counting rates of 10⁵events/s.     

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.     

General Shear-Thinning Dynamics of Confined Fluids

The shear properties for a number of thin fluid films under high pressure were investigated as a function of sliding velocity (shear rate) using the surface forces apparatus. It was found that the relationship between the effective viscosity _eff and shear rate in the shear-thinning regime could be expressed by a simple equation, log_10eff=C-nlog₁₀, where C4.7±0.2 and n0.9±0.1. This equation can be applied to a variety of fluid systems from simple liquids to polymer melts, which transition to glasslike phases in confined geometries. Since the effect of confinement on the slowing down of molecular motions is equivalent to that of decreasing temperature, this universally can be explained using conventional glass-transition theories for bulk fluids. Assuming the confined fluid to be in a state where dynamics are dominated by excluded volume effects, its _eff should correspond to that of the bulk at or near the glass-transition temperature. Thus, characteristic relaxation times in the system should correlate with the time scales of the primary relaxation processes associated with submolecular rearrangements, which are an essential feature of the glass transition and not very different for various fluid materials.     

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 Combination β–γ-Radiometer and Dose-Rate Meter with an Extended Dynamic Range

A MKC-07 –-radiometer and dose-rate meter based on Geiger–Muller tubes is described. By using an unconventional signal-processing method, it is possible to extend the dynamic range of the instrument by a factor of 10–50, depending on the type and number of detectors in use, and to significantly reduce the error in measuring time-dependent ionizing-radiation intensities. The combination radiometer and dose-rate meter is used to determine the characteristics of constant and nonstationary ionizing-radiation fields.