2m比长仪纳米级高精度刻线自动瞄准系统

阐述了2m比长仪刻线瞄准系统的组成,对其光电显微刻线成像的原理及刻线图像信号进行了分析,根据其刻线信号的特点,研究了其高精度的刻线信号自动处理系统,该系统基于FPGA现场可编程电路技术,实现刻线信号的自动门控触发、自动滤除虚假刻线信号,配合计算机信号自动处理软件可以实现刻线测量的高精度自动瞄准.最后对2m比长仪的瞄准精度进行了测试实验,实验结果表明,测量金属标准线纹尺时,2m比长仪单次测量刻线瞄准精度优于10nm(1σ).     

基于长信号谱自相关的光纤光栅传感解调方法

针对光纤光栅传感领域波长高精度探测和传感复用光栅数量增多的需要,提出一种基于长信号相关谱的新型光纤光栅数字解调技术.该技术在可调谐滤波法的基础上,通过传感光栅与调制光栅反射谱卷积后的信号,即光电探测器的光强时间信号,进行自相关分析以实现对波长漂移的测量以及对传感光栅反射谱形状的识别,增强系统的复用能力,提高了性价比.模拟仿真表明,光纤光栅长信号相关数字解调方法可以准确测量光纤光栅波长的漂移,能更好实现传感复用.等强度悬臂梁实验验证该解调方法能实现光栅应变的高精度测量,优于传统的应变片测试.     

激光干涉比长仪的瞄准方法

本文提出一种改进型的单狭缝刻线瞄准方法,通过计算刻线信号重心坐标平均值,确定刻线中心位置,实验结果表明因刻线信号形状不规则引起的误差小于4nm;通过简化算法将计算时间缩短到1s以内,实现了测量数据的实时处理。     

2m比长仪纳米级精度线间距测量系统的研究

介绍了2 m比长仪系统的组成,对其采用光电显微镜动态瞄准刻线和激光干涉测长原理进行了分析,研究了提高刻线瞄准精度和激光干涉测长精度的方法及利用现代电子技术实现刻线信号和干涉信号自动同步快速处理方法。自动信号处理系统基于FPGA现场可编程电路技术和计算机技术。通过对金属线纹尺测量的实验表明,依据JJG 331—1994激光干涉比长仪检定规程进行实验,2 m比长仪单次最佳刻线瞄准精度优于10 nm(1σ),对其测量的不确定度分析表明,对于测量高质量的高等别线纹尺,其测量不确定度U=（20+40 L）nm（k=2）。     

圆光栅单常角检测的富里叶分析

光栅盘作为计量元件,广泛应用于科研生产的许多部门。由于工艺技术的进步和许多新技术的应用,其制造精度越来越高,因而对其检测技术的要求也越来越高。光栅盘各刻线的实际位置与理论位置之间的角差称为刻线误差。在很多仪器中,为了消除光栅盘安装偏心的影响,都采用对径提取信号的方法,因此对光栅盘的要求就不再是刻线误差而是直径误差。在光电检验仪上检测直径误差主要有两种方法:比较法(绝对法)和常角法。比较法就     

光栅莫尔条纹细分及辨向方法研究

提出了一些新的基于数字处理技术的莫尔信号细分及辨向方法.单光栅副莫尔条纹采用差值细分方法;双光栅副莫尔条纹采用乘积细分法.将信号进行区间划来实现辨向.实验采用DSP器件内置的高速A/D模块实现数/模转换,利用DSP专用指令实现信号的滤波、细分和辨向.实验结果表明,单光栅副和多光栅副的细分精度分别为3"和0.3".     

光栅内插值细分及补偿

本主要给出光栅输出原始信号的正弦分量中提取与光栅刻线间距的有关数字信息以及将其间的正弦模拟量采样量化经分后进行内插值补偿运算。可提高光栅传感器测量准确度和分辨力。     

提高光栅测角仪器精度的多读数头读数平均法

一、前言光栅测角系统一出现,引起了人们极大的兴趣,其重要性不仅在于能实现数字显示、动态测量和自动测量等,更重要的是为测角仪器精度的进一步提高展示了美好的前景。提高光栅测角仪器精度的方法主要是利用平均误差原理。平均误差方法有两个方面的含义,一是接收窗口的平均误差作用,一是多读数头的平均误差作用。如果接收窗口长度(即垂直于光栅刻线方向上的尺寸)恰好等于光栅盘的某个短周期或中周期误差周期的整倍数,则可消除该周期误差的影响。对于周期小于接收窗口长度1/3的中周期、短周期误差,由于平均误差的作用,已使这些误差的影响减至1/10以下。接收窗     

纳米计量光栅传感器的应用

计量光栅就是在玻璃、金属等基体上刻有密集规则线条的计量元件。我们将刻线准确度达到纳米量级的计量光栅称为纳米计量光栅．简称纳米光栅。它与传统的计量光栅相比。具有超精和超细两个特征。我国从上世纪50年代开始刻线技术的研究，其中，计量光栅技术是研究的重点。近20年来，计量光栅技术提高到了纳米量级和亚纳米量级，形成了一整套纳米光栅测量技术，并且以这套技术为依托在北京郊区建立了基地。进行大范围推广应用。     

衍射法X射线激光分束光栅平行度测量系统(英文)

介绍了软X射线光栅分束镜Mach-Zehnder干涉等离子体诊断系统调整用双频光栅线条平行度的衍射法测量系统.该系统主要由激光器,准直镜,待测光栅,精密转台(含角度测量仪),直线工作台,光栅调节架和探测器组成.分析了系统中各种误差对测量精度的影响其中包括距离测量误差、波长误差、光栅准直误差即光栅刻线与入射光和反射光组成的平面不垂直、光栅转动过程的误差、光栅表面面型误差、探测器误差,经计算得到系统的绝对误差为minute.计算表明,该系统的测量精度满足软X射线Mach-Zehnder干涉系统对双频调整光栅的性能要求.     

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.