SEM—past,present and future

The development of the technology of the scanning electron microscope (SEM) is traced from the early pioneering work in the 1930s to the present day. Recent trends are described and, based on these, some speculative forecasts are made of possible future developments. It is suggested that these will include better vacuum conditions in conventional SEM to permit more accurate surface characterization, and improved electron optics for higher resolution, particularly with low-voltage operation.     

Textiles as aseptic barriers: the past, present, and future

Operating room drapes and gowns have changed over the years to reflect the changing attitudes toward and thoughts on textiles as asceptic barriers. Although gowning and draping techniques differed from hospital to hospital, by 1900 the importance of these techniques was generally recognized. It was not until 1975, however, that the textile industry was charged with the responsibility for developing performance standrads for gowning the draping materials.     

TEM in materials science—past,present and future

The progress in transmission electron microscopy as applied in materials science is reviewed briefly, from the era of replica techniques in the 1940s and 1950s, through the development of the diffraction contrast technique in the late 1950s and 1960s, to the present day when instrumental resolution is sufficient to obtain structure images of a wide variety of crystalline solids. One of the most important advances has been the development of combined imaging and microanalytical techniques in a single instrument. The versatility of the TEM technique with atomic resolution and microanalytical facilities, the variety of signals and contrast effects available, and its universal application, establishes it as an essential tool in materials science for the foreseeable future.     

数控机床发展的过去和现实

数控机床是电子信息技术与传统机床技术相融合的机电一体化产品,具有高效、精密、柔性自动化和易于实现工艺复合和信息集成诸特点,特别适于加工复杂形状的零件,因而早已成为现代先进制造技术最重要的基础装备和世界机床市场的主流产品,受到机械制造企业的青睐。 一、我国数控机床发展回顾 工业发达国家数控机床的发展大体上经历了缓慢、快速和深入发展三个价段,目前已达较高水平,其机床(含金切和成形机床)产值数控化率至少超过50％,产量数控化率至少超过20％。内中金切机床数控化率最高,比如号称“数控王国”的日本,2000年金     

Past,present and future of electron holography

Electron holography, originally devised for improving the resolution of electron microscopes, progressed significantly with the advent of the ‘coherent’ field-emission electron beam. This permitted high-resolution microscopy (Lichte, 1986), and opened up such new fields as high-precision electron interferomentry. This paper briefly describes the developments in electron holography.     

Safe physical human robot interaction-past,present and future

When a robot physically interacts with a human user, the requirements should be drastically changed. The most important requirement is the safety of the human user in the sense that robot should not harm the human in any situation. During the last few years, research has been focused on various aspects of safe physical human robot interaction. This paper provides a review of the work on safe physical interaction of robotic systems sharing their workspace with human users (especially elderly people). Three distinct areas of research are identified: interaction safety assessment, interaction safety through design, and interaction safety through planning and control. The paper then highlights the current challenges and available technologies and points out future research directions for realization of a safe and dependable robotic system for human users.     

Ultra-high voltage electron microscopy: Past,present, and future

High voltage electron microscopy has shown numerous advantages for the study of natural science, including biology, but it is especially useful in materials science. The most important advantage for materials science is in-situ experiments on detailed processes of the same phenomena that occur in bulk materials. For such in-situ experiments, the specimens should be thicker than a few microns to observe the behavior of lattice effect. The maximum observable thickness of the specimens and other advantages markedly increase with increasing accelerating voltage, and since 1965, two 3 MV instruments have been installed. The present paper is mainly concerned with these 3 MV electron microscopes and their applications to new research fields.     

Basic research on machinery fault diagnostics: Past,present, and future trends

Machinery fault diagnosis has progressed over the past decades with the evolution of machineries in terms of complexity and scale. High-value machineries require condition monitoring and fault diagnosis to guarantee their designed functions and performance throughout their lifetime. Research on machinery Fault diagnostics has grown rapidly in recent years. This paper attempts to summarize and review the recent R&D trends in the basic research field of machinery fault diagnosis in terms of four main aspects: Fault mechanism, sensor technique and signal acquisition, signal processing, and intelligent diagnostics. The review discusses the special contributions of Chinese scholars to machinery fault diagnostics. On the basis of the review of basic theory of machinery fault diagnosis and its practical applications in engineering, the paper concludes with a brief discussion on the future trends and challenges in machinery fault diagnosis.     

数控机床的现状与发展

数控机床及由数控机床组成的制造系统是改造传统产业、构建数字化企业的重要基础装备,它的发展一直备受人们关注.数控机床以其卓越的柔性自动化的性能、优异而稳定的精度、灵捷而多样化的功能引起世人瞩目,它开创了机械产品向机电一体化发展的先河,因此数控技术成为先进制造技术中的一项核心技术.另一方面,通过持续的研究,信息技术的深化应用促进了数控机床的进一步提升.     

Observations on the present and future of mass customization

A demanding task for many companies today is that of learning to regard customers as individuals, of proactively developing products and services according to the individual customer preferences, and of subsequently producing and distributing these offerings. Over the last decade, mass customization has emerged as an effective approach for tackling precisely this task. In this paper, I discuss the background of mass customization and the elements of this strategy. I will then comment on the implementation of mass customization in practice. I will end with a brief discussion of alternative strategies in this domain, namely personalization and matching services.     

Biological stereology: history, present state, future directions.

The development of a quantitative structural platform for experimental biology--extending across a hierarchy of sizes ranging from molecules to organisms--has been punctuated by a series of major achievements over the last 30 years. Stereology, a form of quantitative morphology, has contributed handsomely to this success. A personal view is presented highlighting key events in the development of biological stereology. We also examine stereology with a view toward future developments in biology and speculate how stereology might contribute to the new biological infrastructure currently being built with computers.     

Past,present and future of nonlinear system identification in structural dynamics

This survey paper contains a review of the past and recent developments in system identification of nonlinear dynamical structures. The objective is to present some of the popular approaches that have been proposed in the technical literature, to illustrate them using numerical and experimental applications, to highlight their assets and limitations and to identify future directions in this research area. The fundamental differences between linear and nonlinear oscillations are also detailed in a tutorial.     

食品包装机械的现状、未来和存在的问题

一、我国食品包装机械发展基本情况1、生产发展回顾中国食品包装机械起步于1958年。在这之前,生产食品基本上都是手工作坊式的前店后厂,只使用一些简单的工具,没有机械作业。1958年大搞技术革新才由各企业自行研制了一些简单的食品机械。     

夹片齿的啮合作用研究

分析了液压同步提升器中夹片式锚具和传统预应力锚具的工作机理,研究了钢绞线和夹片齿部啮合作用关系,建立了相应的数学模型和仿真分析模型,并对夹片齿强度、容污能力进行定性评估.研究结果表明:夹片和钢绞线间的匹配硬度、夹片齿形状和参数、齿面的几何形状是改善夹片齿工作性能的关键因素,这为齿形和夹片的优化设计及其工作寿命预测提供了依据.