基于德尔菲法和FAHP的特种车辆设计评价体系研究

针对特种车辆概念设计方案中的诸多模糊因素,利用AHP方法构建了概念设计方案的多目标、多层次评价指标体系,根据德尔菲法由专家打分的方式并结合FAHP法确定各评价因素的权重,并建立了特种车辆设计方案模糊综合评价模型。通过对广东某特种车辆制造公司的罐式运输车设计方案评价,实例验证了该评价体系在特种车辆设计方案评价中的应用。     

特种陶瓷与制药装备

作为一种新型的材料，特种陶瓷具有许多其他材料没有的优越性，因此可引入制药装备行业应用。从介绍特种陶瓷及其特性入手，探讨了特种陶瓷在制药装备中的应用，并认为其具有良好的发展前景。     

浅谈特种加工在现代制造业中的应用

20世纪以来，制造技术．特别是先进制造技术不断发展，作为先进制造技术中重要的一部分，特种加工对制造业的作用日益重要。介绍了特种加工的涵义、特点以及特种加工在机械制造中的具体应用。     

特种挖掘机在基础建设中的应用

拆除挖掘机前端的铲斗,配置某种专用属具,就可以完成很多特定作业,这些用于特定作业的挖掘机称为特种挖掘机。简要介绍特种挖掘机在基础建设中的应用。     

依靠标准建设与实施 促进特种施工装备行业发展

正特种施工装备是国民经济和人民生活的重要基础设施,其技术先进性和安全可靠性直接关系到经济社会和谐稳定发展。发挥标准化在特种施工装备产业技术进步中的基础性和战略性作用,推动"标准化+"与特种施工装备的深度融合,对提升特种施工装备技术进步、保障装备安全可靠性、推动产业发展具有重要意义。一、夯实标准化基础,健全标准化体系     

特种车辆的中底架结构分析计算

中底架是特种车辆中的主要承载部件,其设计的优劣将直接影响特种车辆的性能。文中采用有限元法对特种车辆中底架进行了强度、刚度、挠跨比分析及稳定性计算,为中底架设计提供了参考依据。     

JB／T 10208—2000《电火花加工机床 操作指示形象化符号》介绍

1　概述JB3750-1984《产品类种划分》中,特种加工机床(原称“电加工机床”,下同)仅作为金属切削机床大类中的第11小类。但特种加工机床在品种、结构性能、布局型式及功能等方面都有了很大的发展,已形成一个独立的机床行业,目前我国特种加工机床拥有量已达十万台左右(“电火花加工机床”占其中98%以上),外销和进口量都在不断上升。机械工业标准体系表已将特种加工机床作为大类考虑,而电火花加工机床又是特种加工机床中的主体部分,因此,制定独立完整的电火花加工机床操作指示形象化符号已刻不容缓(GB/T3167-1993《金属切削机床　操作指示形…     

特种加工方法的内容和趋势

特种加工方法,是难切削材料、复杂型面、精细表面、低刚度零件及模具加工中的重要工艺方法.介绍了特种加工的技术特点,分别论述了电火花加工、电化学加工、高能束流加工、物料切蚀加工和复合加工技术特点与最新进展,并预测今后特种加工的发展方向,最后给予特种加工技术展望.     

试析特种车辆永磁同步电动机的工程设计

现今随着科学技术突飞猛进的发展,特种车辆的实际应用范围也变得更加广阔,但是特种车辆在实际工作过程中的工作能力以及表现出的专业功能主要受到车辆中永磁同步电动机的影响。永磁同步电动机具有很多优点,如电机的体积较小,质量相对轻便,运行中可靠性比较高,这些优点能有效提升特种车辆在实际使用过程中的性能。永磁同步电动机具有如此高性能的有点与其自身的设计是分不开的。     

特种车辆小底架结构分析

小底架是特种车辆中的主要承载部件。其设计的优劣将直接影响特种车辆的性能。文中对特种车辆小底架进行了结构分析及稳定性计算。采用有限单元法对小底架结构的强度、刚度、挠跨比进行了分析计算,为小底架设计提供了参考依据。     

LED光源和CCD在荧光显微镜上的应用研究

荧光显微镜是常用的医用光学仪器之一,分布在各大医院科研、病理、检验等部门。光源是荧光显微镜的主要组成部分,使用新型的LED光源替代传统的高压汞灯,以及把数码相机改为CCD摄像装置,使现有的荧光显微镜上了一个等级,达到现代荧光显微镜的水平。     

A compact sensor head for simultaneous scanning force and near-field optical microscopy

A compact sensor head based on scanning force microscopy (SFM) using cantilever probes has been developed. The idea is to replace the microscope objective of a conventional optical microscope by this compact module and turn the optical microscope into a scanning force and near-field optical microscope with subwavelength resolution. We describe our concept and present initial results showing images of the object’s optical properties and surface topography recorded simultaneously.     

Low-dose aberration corrected cryo-electron microscopy of organic specimens

Spherical aberration (C(s)) correction in the transmission electron microscope has enabled sub-angstrom resolution imaging of inorganic materials. To achieve similar resolution for radiation-sensitive organic materials requires the microscope to be operated under hybrid conditions: low electron dose illumination of the specimen at liquid nitrogen temperature and low defocus values. Initial images from standard inorganic and organic test specimens have indicated that under these conditions C(s)-correction can provide a significant improvement in resolution (to less than 0.16nm) for direct imaging of organic samples.     

数码显微镜的设计

介绍了数码显微镜光学系统的设计方法,实现了数码显微镜总体尺寸的缩短,符合数码显微镜小型化的发展方向。采用了多头螺纹调焦机构,改变了传统显微镜由齿轮通过齿条带动镜筒的调焦方式,在调焦过程中具有调焦精细,手感舒适,影象清晰的优点,该结构有利于微型马达的驱动,容易实现数码显微镜调焦的自动化。用精密螺纹连接燕尾槽工作台与调节旋钮,工作台始终在燕尾槽内平稳滑动,克服了数码显微镜在观察移动物体时影像容易晃动的难题。样机研制的结果表明:数码显微镜成象清晰,且结构简单、可靠,光学性能和机械结构均满足设计要求。     

Editorial

The performance of many electron optical instruments is fundamentally limited by the dimensions of the focused probe. This is true of the scanning electron microscope and the scanning transmission electron microscope and, by inference, it may affect the transmission electron microscope. There has been very little improvement over the past few years and it seems reasonable to look for the explanation. It is possible to arrive at some simple expressions for the limiting performances of conventional instruments in a way that is independent of the design details and depends upon practical limits of field strength. Experiment and theory also appear to be in agreement with the fact that the limit for high-voltage instruments has been reached, although there is still room for improvement for low voltages.     

基于共焦显微条件下线结构光共焦显微术的研究

美国的Minsky在20世纪50年代末提出共焦显微术的概念以来,尽管共焦显微术可以获得更高的分辨率,但不仅成像速度慢,而且需要使用光电增强器对采集光点信号进行增强,导致制造成本过高,所以除一些成像质量要求极高的显微系统外,其他的显微系统很少应用。讨论了线结构光共焦显微术的原理、优缺点以及影响性能的几个重要因素,并介绍其最新的研究状况。     

Cone-beam reconstruction of plate-like specimens

An x-ray shadow projection microscope using a scannable point source of x-rays is under development at AMIL-ARTS, SUNY at Buffalo. Considering the characteristics of the x-ray microscope of AMIL-ARTS and the limitations of Feldkamp's cone-beam reconstruction algorithm, a general cone-beam image reconstruction algorithm has been developed. In x-ray microscopy, many specimens are plate-like. The reconstruction of a plate-like specimen appears to be a limited angle problem. A novel method is presented to reconstruct a plate-like specimen using the general cone-beam reconstruction algorithm. Shepp and Logan's head phantom is used in validating this method. A method for synthesizing projection data of ellipsoids is described. Typical simulation results are given.     

The electron microscope: The British contribution

The unpredictable development of the electron microscope is reviewed in the context of the 150th Anniversary of the Royal Microscopical Society. Abbe convinced himself that an electron microscope could never be constructed. Later, J. J. Thomson established the minute corpuscular nature of the electron and Rutherford realized that such beams can reveal the nature of the atom; his student H. G. Moseley invented electron probe analysis, while looking for X-ray spectra, but the technique did not seem very practical. G. P. Thomson invented the electron diffraction camera, but it was of limited use without an electron lens. In 1931, Knoll and Ruska built a two-stage TEM with magnetic lenses and understood where Abbe went wrong. Although Ernst Ruska surpassed the resolving power of the light microscope in 1933, the first commercial TEM was manufactured in the U.K., leading to many further commercial developments. The realization of a digital computer with a stored program, now indispensible in microscopy, was also achieved first in the U.K. Gabor's electron beam holography, invented in Rugby in 1949, was not a challenge to the conventional TEM at first, but recently atomic resolution holography has been achieved in Abbe's native country, using a digital computer to process the hologram, ironically making use of the very principles laid down by Abbe in the last century for the light microscope.     

Circularly polarized luminescence microscopy for the imaging of charge and spin diffusion in semiconductors

Room temperature electronic diffusion is studied in 3?μm thick epitaxial p(+) GaAs lift-off films using a novel circularly polarized photoluminescence microscope. The method is equivalent to using a standard optical microscope and provides a contactless means to measure both the charge (L) and spin (L(s)) diffusion lengths simultaneously. The measured values of L and L(s) are in excellent agreement with the spatially averaged polarization and a sharp reduction in these two quantities (L from 21.3 to 1.2?μm and L(s) from 1.3 to 0.8?μm) is found with increasing surface recombination velocity. Outward diffusion results in a factor of 10 increase in the polarization at the excitation spot. The range of materials to which the technique can be applied, as well as a comparison with other existing methods for the measurement of spin diffusion, is discussed.     

正交实验方法在激光焊接中的应用

为获得优先的激光焊接工艺参数,采用四因素、三水平的正交实验方法设计激光焊接实验,以抗拉强度为标准,获得焊接优化水平参数为电流180A,脉宽3ms,频率30Hz,速度10mm/s.采用金相显微镜、显微硬度计、激光扫描显微镜、万能实验机等设备对焊接接头做金相分析、硬度测试以及拉伸试样断口分析,焊接接头硬度、基材硬度范围为H...