圆钢直径在线测量仪及其误差分析

１测量原理热轧圆钢直径在线测量仪采用光学非接触法在线测量轧制产品水平方向和垂直方向的直径几何尺寸，以供轧机的随时调整。图１为仪器的工作原理图。光源１经聚光镜２、光栏３、透镜４形成平行光束，由半透半反镜５分成反射光路和透射光路。反射光路经分光镜１６和反射镜２１形成两束平行光照射到被测工件的上下边缘，通过物镜１８和２３成像在ＣＣＤ器件２０和２５上，由影像在ＣＣＤ上所覆盖的像素数加两平行光间距Ｄ０即为工件垂直方向直径大小。同理，透射光路亦可测得工件水平方向的直径大小。由图１可知，被测工件的直径Ｄ为：Ｄ…     

300mm以上千分尺平面度、平行度的修理

修理300mm以上千分尺平面度、平行度时,可将其安置在JGA激光千分尺平行度检查仪上进行。在检修中,笔者有以下两点体会: 1.在检修几把类型相同的外径千分尺时,可将其中一把尺的弓架装在仪器上,然后装上其余各尺的测微杆,按步骤修理好平面度和垂直度。在仪器上以修好的测微杆测量面为基准,检修测砧测量面。这样可减少装拆研磨     

用于大平板测量的激光平面度仪

“激光平面度仪”是以空间自动安平的激光面作基准．以光电测头自动跟踪被测面．通过计算机控制和数据处理及输出的新型几何面型测量仪器。该仪器的研制成功,解决了平面测量过程“统一基准测量”这个国标难题;使得几何面型测量实现高精度智能化,并能带加工中心实现面型“光控加工”．论文对仪器工作原理、主要部件设计、仪器精度进行了分述和计算．     

大型工件平面度平行度垂直度误差计算与评定方法

提出了一种实用的大型工件平面度、平行度、垂直度误差的计算与评定方法。这种方法适用于各种不规则、不连续的测量表面。评定程序采用最小二乘和最小条件法，搜素速度快，评定结果精度高。     

自准直仪在垂直度测量中的应用

用自准直仪测量垂直度,具有方法简便易行、可直接在生产现场使用且测量准确度较高等特点。现将我厂在生产中的两应用实例介绍如下。一、端面对内孔轴线的垂直度测量我厂生产的某零件,其端面平面度、端面对内孔轴线的垂直度要求都很高。生产中,若采用研磨、送检、再研磨的方式,费时费力,效率低。为此,我们设计了一套测量装置(见图1),在生产现场实现了垂直度的高准确度、快速测量。其中,镶嵌在工装上的5个钢球(排列见图2)使工件能准确定位。测量时转动工件,通过自准直仪中读数变化即可求出所测的垂直度。二、四方块类零件各相邻面间垂直度的测…     

基于双光栅的平行度检测

为了对大型目标的平行度进行测量,设计并搭建了一套由双衍射光栅组成的平行度检测系统。采用两块衍射光栅正交组成光路,产生多条平行线作为基准线。通过照相机对参考线和待测目标进行拍照,对获得的图像进行处理,利用参考线的平行度偏差对目标所在平面的倾斜进行矫正,得到待测物的平行度测量结果。测量结果表明这种方法简单准确,满足测量精度高。     

箱体类零件快速测量的研究

研究了箱体类零件的快速测量方法.研制了一台车辆变速箱体测量仪器,在这台仪器上布置了46个电感传感器,可同时对10个孔和2个平面进行测量.当传感器的触头与被测件的几何特征点接触时,计算机采集传感器的信息,通过预先编制的程序计算出被测零件的孔径、孔距、孔系平行度、孔轴线与平面的垂直度等多个几何量的测量结果,测量过程在几分钟内完成.文中并分析了这种测量方法的测量不确定度.     

检定螺纹千分尺“校对量规”的测量装置

通常采用工具显微镜测量螺纹千分尺的“校对量规”半角。本文介绍检定“校对量规”测量面间尺寸的一种方法。其步骤如下: 自制空心测帽(见图1a) 工艺要求为: 1.A、B面不平行度为0.001mm; 2.φd轴心线与A、B面垂直度不大于0.002mm。首先将测帽安装在卧式测长机或同类型光学比较仪的尾管上,另一端光学计管装上仪器     

高精度锥体圆度测量方法的探讨

一、问题的提出测量回转体的圆度误差通常采用轴心基准法、V 形块法和三表法。目前测量圆锥体的圆度误差一般采用第一种方法,即用圆度仪测量。在测量高精度工件的过程中,工作台与主轴回转中心线及被测圆锥体的几何中心线与其端面垂直度误差对测量结果会有一定的影响。垂直度误差究竟能够引起多大的圆度测量误差?仪器主轴的回转中心线与圆锥体几何中心线的夹角γ在多大的情况下能满足测量准确度的要求?     

用三坐标仪检测两圆柱轴线定向误差

三坐标测量仪通用测量软件可对两圆柱轴线定向误差进行检测,是一种新研制的快捷精确的测量方法,可广泛用于各类工件两圆柱轴线的平行度、垂直度及倾斜度误差检测,工件可任意摆放,对大型工件测量显得更方便。     

凝固科学技术与材料

从凝固科学与实践发展的角度介绍了当前凝固材料体系的基本框架和凝固科学主要发展阶段的基本理论。作为材料科学与工程的基本组成，凝固科学技术正在现代科学理论的基础上针对传统材料的改性提高和新材料的发展需求，以控形、控构、控性为目标开展优质铸件的定向、晶体生长、快凝、深过冷及各种新型和超常领域凝固过程的研究，并介绍了其中某些方面和展望了可能的发展趋势。     

Development and challenges of planning and scheduling for petroleum and petrochemical production

Production planning and scheduling are becoming the core of production management, which support the decision of a petrochemical company. The optimization of production planning and scheduling is attempted by every refinery because it gains additional profit and stabilizes the daily production. The optimization problem considered in industry and academic research is of different levels of realism and complexity, thus increasing the gap. Operation research with mathematical programming is a conventional approach used to address the planning and scheduling problem. Additionally, modeling the processes, objectives, and constraints and developing the optimization algorithms are significant for industry and research. This paper introduces the perspective of production planning and scheduling from the development viewpoint.     

江澳两地高校文创设计的协同研究与商业实践

目的 探索江门世遗文化的传承、发展和转化的新思路,践行国家在《粤港澳大湾区发展规划》纲要中要求江门承担与港澳地区文化创意合作与开发任务的分工。方法 与澳门高校紧密合作,开展专业培训课程,以开平碉楼为例,从人文视角开展设计研究,梳理开平碉楼的文化脉络,把世遗文化的元素和其背后的文化融入文创产品中,提升文创产品的附加值,推动当地文创产业结构的变革。结果 两地高校构建了稳定的科研团队,开设长期有效的设计培训课程,与景区建立了研究协作关系,帮助景区构建了一套产销研的商业模式。结论 以跨区域高校合作为平台,以文创产品为抓手,依托江澳两地的资源优势,可以构建江门世遗文化全新的品牌形象,最终推动开平世遗文化的活化。     

Error and uncertainty in modeling and simulation

This article develops a general framework for identifying error and uncertainty in computational simulations that deal with the numerical solution of a set of partial differential equations (PDEs). A comprehensive, new view of the general phases of modeling and simulation is proposed, consisting of the following phases: conceptual modeling of the physical system, mathematical modeling of the conceptual model, discretization and algorithm selection for the mathematical model, computer programming of the discrete model, numerical solution of the computer program model, and representation of the numerical solution. Our view incorporates the modeling and simulation phases that are recognized in the systems engineering and operations research communities, but it adds phases that are specific to the numerical solution of PDEs. In each of these phases, general sources of uncertainty, both aleatory and epistemic, and error are identified. Our general framework is applicable to any numerical discretization procedure for solving ODEs or PDEs. To demonstrate this framework, we describe a system-level example: the flight of an unguided, rocket-boosted, aircraft-launched missile. This example is discussed in detail at each of the six phases of modeling and simulation. Two alternative models of the flight dynamics are considered, along with aleatory uncertainty of the initial mass of the missile and epistemic uncertainty in the thrust of the rocket motor. We also investigate the interaction of modeling uncertainties and numerical integration error in the solution of the ordinary differential equations for the flight dynamics.     

Density and viscosity of tetralin and trans-decalin

New measurements are reported for the density and viscosity of tetralin and trans-decalin. The density was determined from room temperature to 60°C for tetralin and to 95°C for trans-decalin. The kinematic viscosity was measured up to temperatures slightly above 100°C. Our results improve upon the values recommended by the American Petroleum Institute for these liquids.     

Creation and motion of dislocations and fracture in metal and silicon crystals

By making a step on one surface ( ) of a rectangular small paralellepiped copper crystal, dislocations could be created by the molecular dynamic method. The dislocation created was not a complete edge dislocation but a pair of Heidenreich-Shockley partial dislocations. Each time a dislocation was created, the stress on the surface was released. Small copper crystals having a notch were pulled (until fracture), compressed and buckled by use of the molecular dynamic method. An embedded atom potential was used to represent the interaction between atoms. Dislocations were created near the tip of the notch. A very sharp yield stress was observed. The results of high speed deformations of pure silicon small crystals using the molecular dynamics are presented. The results suggest that plastic deformation may be possible for the silicon with a high speed deformation even at room temperature. Another small size single crystal, the same size and the same surfaces, was compressed using molecular dynamic method. The surfaces are {110}, {112} and {111}. The compressed direction was [111]. It was found that silicon crystals are possible to be compressed with a high speed deformation. This may suggest that silicon may be plastically deformed with high speed deformation.     

SMC／BMC的回收与再利用

SMC／BMC废弃物对工业及环境造成了很大影响，指出了SMC／BMC回收再利用的紧迫性。通过对目前国际上SMC／BMC回收再利用的3种典型途径优缺点的对比，参照国外SMC／BMC回收再利用的先进方法，对我国SMC／BMC回收再利用提供了可行的建议．     

The Candela and Photometric and Radiometric Measurements

The national measurement system for photometric and radiometric quantities is presently based upon techniques that make these quantities traceable to a high-accuracy cryogenic radiometer. The redefinition of the candela in 1979 provided the opportunity for national measurement laboratories to base their photometric measurements on optical detector technology rather than on the emission from high-temperature blackbody optical sources. The ensuing technical developments of the past 20 years, including the significant improvements in cryogenic radiometer performance, have provided the opportunity to place the fundamental maintenance of photometric quantities upon absolute detector based technology as was allowed by the 1979 redefinition. Additionally, the development of improved photodetectors has had a significant impact on the methodology in most of the radiometric measurement areas. This paper will review the status of the NIST implementation of the technical changes mandated by the 1979 redefinition of the candela and its effect upon the maintenance and dissemination of optical radiation measurements.