新型电容式靶式流量计的设计

介绍了基于差动电容结构的新型靶式流量计的基本结构、工作原理,设计了以MSP430f147为主控制器的二次仪表,通过滤波、线性修正、密度补偿等数字处理,实现对瞬时流量、累积流量等的测量与实时显示,并提供多种通讯输出方式.试验结果表明,新型电容式靶式流量计灵敏度好、量程比高、适应性强,能实现高精度、高稳定性的流量测量.     

全新概念的靶式流量计——WELKIN（纬尔科恩）推出应片式靶式流量计

靶式流量计是60年代随着工业生产中迫切需要解决高粘度、低雷诺数流体的测量而发展起来的流量仪表。它通过一块靶板将流体所携带的动压能转化为对靶的作用力,再经过检测靶板所受作用力的大小,从而得到相应的流速及流量。这种通过应用流体动压力测量流量的方法,以其结构简单、适用于高粘度、低雷诺数的流体及含有微小颗粒的流体的测量而得到广泛的应用。     

靶式流量变送器非标靶板的设计

靶式流量变送器靶板已标准化、系列化,并被广泛地应用于工业生产过程中的高粘度、低雷诺数的不可压缩流体的测量。为了应用在压缩空气的测量上,必须重新设计靶板,方能收到运行稳定、测量准确的效果。     

靶基距对直流反应磁控溅射制备TiO2薄膜光学性质的影响

应用DC(直流)反应磁控溅射设备在硅基底上制备TiO2薄膜,在固定的电源功率下,氩气流量为42.6 sccm,氧流量为15 sccm,溅射时间为30 min的条件下,通过控制靶基距改变TiO2薄膜的光学性质.应用n&k Analyzer 1200测量,当靶基距增加时薄膜的平均反射率降低,同时反射低谷先短波后长波之后再短波;靶基距对消光系数k影响较大;随着靶基距的增加薄膜的折射率出现了下降的趋势,但当靶基距达到一定的量值时折射率的变化趋于稳定.通过XRD和SEM表征发现,随着靶基距的增加TiO2的晶体结构由金红石相向锐钛矿相转变,薄膜表面的颗粒度大小由粗大变得微小细密.     

一种气体缓流流量测量用传感器的研究

本文提出了一种采用悬挂靶的流量传感器，并对其工作特性进行了理论分析及试验研究，这种传感器具有很好的低流速（流量）测量特性，并且具有易于交换量程，工作可靠等优点，试验表明，悬挂靶式流量传感器可测量流速低于１ｍ／ｓ的空气管流。     

靶基距对直流反应磁控溅射制备TiO2薄膜光学性质的影响

应用DC(直流)反应磁控溅射设备在硅基底上制备TiO2薄膜,在固定的电源功率下,氩气流量为42.6 sccm,氧流量为15 sccm,溅射时间为30 min的条件下,通过控制靶基距改变TiO2薄膜的光学性质.应用n&k Analyzer 1200测量,当靶基距增加时薄膜的平均反射率降低,同时反射低谷先短波后长波之后再短波;靶基距对消光系数k影响较大;随着靶基距的增加薄膜的折射率出现了下降的趋势,但当靶基距达到一定的量值时折射率的变化趋于稳定.通过XRD和SEM表征发现,随着靶基距的增加TiO2的晶体结构由金红石相向锐钛矿相转变,薄膜表面的颗粒度大小由粗大变得微小细密.     

CCD立靶弹丸攻角测量

基于CCD立靶坐标交汇测量原理,提出了通过测量弹头和弹尾过靶坐标进而解算出弹丸攻角的方法,使CCD立靶测量系统在完成弹丸着靶坐标测量的同时,还可以完成弹丸攻角的测量.对CCD立靶坐标测量精度进行了分析,推导了攻角测量的相关公式;结合试验,对攻角测量精度作了分析,对方法的可行性进行了验证.结果表明,利用CCD立靶测量系统...     

CCD立靶坐标测量系统精度仿真分析

根据CCD立靶坐标测量系统的工作原理,对系统测量精度进行了理论分析,建立了系统测量精度数学模型,利用计算机仿真技术对其进行仿真计算,1 m靶面的测量精度为0.8 mm×1.0 mm;4 m靶面的测量精度为3.0 mm×3.0 mm.通过理论计算和试验结果的对比,证明该数学模型可准确描绘系统的测量精度.     

称量法脉冲流量测量系统

为提高脉冲流量测量精度,在体积管的基础上,设计了称量法脉冲流量测量系统,减少了密度对质量流量测量精度的影响,并提高了压力和量程的适用范围.试验结果表明,系统精度高,满足脉冲流量测量要求.     

线列 CCD 像机交汇测量精度分析

目的　探讨提高线列 CCD像机交汇测量精度 ,在此基础上分析了 CCD像机交汇测量的原理 .方法　采用空间虚拟的光电靶代替实物靶来实现对弹丸目标脱靶量的实时获取 .结果与结论　在分析了 CCD像机测角精度与布站方式等影响交汇测量精度的因素后 ,对光电靶面上不同位置点的 CCD像机交汇坐标测量结果进行了计算 ,最终给出了测量精度与布站的关系 .CCD像机视轴正交时系统具有最高的测量精度 .     

Electronic Speckle‐Pattern Interferometry Measurements of Structural Ratcheting Strain

Abstract: Several tensile specimens with a central hole were subjected to a cyclic loading for which the Von Mises stress was beyond the initial yield stress in the vicinity of the hole. The tensile machine was fixed together with a phase‐shifting electronic speckle‐pattern interferometry measurement bench that makes it possible to perform strain measurement along the tensile axis. The plastic strain map corresponding to the 30th cycle was obtained. For the considered measurement field, the resolution of the strain measurement is close to 10^?5. By varying the loading, it was possible to detect and observe the deformation corresponding to an early stage of the ratcheting phenomenon. The non‐ratcheting cyclic plasticity behaviour was not observed during the 30th cycle. In the Discussion section, the experimental results were interpreted using Melans’s theorem, which allowed us to determine an upper bound for the yield stress. Eventually, it is shown that the procedure followed in this work could be a way to obtain some interesting data related to the material behaviour laws.     

基于修正Anderson 模型的冲击载荷下地基振动响应预测方法

提出了一个预测潜在冲击载荷下振动效应的理论模型与现场实测相结合的综合预测方法。通过一系列具有针对性的室外重锤冲击振动试验,以及现场实测数据对Anderson模型进行了验证并修正,然后利用修正的Anderson模型预测冲击荷载的振动效应。将预测结果和现场试验结果进行对比分析,结果表明:预测结果与实测结果吻合较好。     

Novel Method for Inside Diameter Determination

Molded component development and release procedures require that numerous dimensions be obtained. Outside dimensions of a part can often be easily measured, but inside dimensions can be difficult to measure especially on small pieces. A new method is described for the measurement of the inside diameter of small orifices. A negative copy of the orifice or cavity is made with a low-shrinkage, harden in place polyester resin. The inside dimensions of the orifice are then taken from the outside dimensions of the copy. The method is equally accurate compared to other methods of measurement, and is much easier to accomplish. The procedure was applied to the study of some critical dimensions of oral inhalers used with metered dose inhalation aerosols.     

Application of the reciprocity theorem to nondestructive evaluation

A review is given of the application of the reciprocity theorem to acoustic measurement of flaws. Starting from the reciprocity theorem derived by Auld and Kino, a discussion of how the theory is applied to cracks and to bulk flaws is given. The experimental results obtained for measurement of crack size and stress intensity factor agree well with the theory.This article is dedicated to Professor Bertram A. Auld on the occasion of his 70th birthday and his retirement from Stanford University.     

A Microcomputer-Based System for Area Measurement

An electronic system developed for area measurement is described. A standard X-Y recorder specially adopted with a light pen was made to scan the area under test and give a TTL logic signal that changes state whenever the area circumference is crossed. From such information the microcomputer is programmed to calculate the area using Simpson's rule and display the result on a seven-segment display. Sources of error in measurement and its nature are investigated. Modifications in the basic system to reduce the error are included. The designed system can also be used for determining the perimeter and locating the centroid of an object.     

一种抗噪性能较强的电感式传感器测量电路

目的　研究一种在环境恶劣的情况下 ,能准确地将微弱电感量变化转化为电压变化的测量电路 ,以便读出、处理及存储 .方法　采用由两级仪表放大器组成的放大电路来提取电感量变化 ,可以大大提高共模抑制比 .同时采用了可行的抗干扰措施和抑制温漂的措施 ,并通过调相位、调幅值两个电位器达到初始调零的目的 .结果　该测量电路用于坦克扭力轴扭力传感器 ,实验表明它是可行的 .结论　该测量电路对于微弱电感量变化的一般电感传感器具有普遍意义 .     

ALC crystal oscillators based pressure and temperature measurement integrated circuit for high temperature oil well applications

An application specific integrated circuit for the pressure and temperature measurement at the high temperature oil well bottom conditions is presented in this paper. The circuit is mainly composed of three high performance automatic level controlled (ALC) oscillator circuits, which drive three external crystals (the sensitive elements), as well as mixing and filtering stages. The integrated circuit was successfully tested up to 220 degrees C, showing a frequency resolution of 0.0003 ppm (0.0007 psi, for the pressure measurement) and a drift of 1.5 Hz/month (0.5 psi/month) concerning, respectively, the short- and long-term measurement stability. A drastic reduction of the whole measurement tool size and cost was then allowed by means of this application specific BiCMOS integrated circuit.     

基于双反馈模式的大范围自感应AFM测量系统

为了提高原子力显微镜（AFM）的测量范围,设计了一种基于双反馈测量模式的大范围自感应原子力显微镜系统,测量系统中有两条反馈回路:一条反馈回路由压电陶瓷与AFM测头组成,动态响应较快的压电陶瓷位移台的运动量可以表征被测样品表面的高频信息;另一条反馈回路由压电陶瓷位移台和纳米测量机（NMM）的反馈控制器组成,利用压电陶瓷位移台的位移信号控制NMM运动,NMM的mm级z向测量范围使得被测样品较大变化范围的低频轮廓信息很容易地被表征出来。使用本系统对平面样品和一维栅格进行了测量实验,实验结果表明采用双反馈的测量模式的AFM测量系统能够有效地表征被测样品的低频轮廓信息和表面高频信息,测量范围能够达到mm级,纵向分辨率达到nm级,具有良好测量重复性。     

投影式数字焦度计

目的　描述一种投影式数字焦度计 .方法　设计的焦度计主要由照明系统、准直系统、投影光学系统组成 .结果　摆脱了目镜系统 ,提高了测量精度 .由于不需要人眼紧贴目镜 ,故操作方便舒适 ,不易疲劳 .结论　实验证明 :所设计的焦度计具有较高测量精度     

Developing a quality measurement tool and reporting format for long- term care

BACKGROUND: Quality measurement in long term care (LTC) presents many challenges: the lack of a uniform definition of quality, the existence of multiple domains for measurement, a multitude of potential perspectives, and regulatory influences that emphasize measurement only of poor quality. Research efforts have yet to solve the issues of measurement; however, operators of long term care facilities must use the current state of the art in quality measurement as the basis for their quality improvement efforts. A project was commissioned by management of a large integrated delivery system with a robust network of LTC facilities who wished to implement a continuous quality improvement process on the basis of a measurement tool that provides a comprehensive resident-centered assessment of quality. The objectives of this project, therefore, were to identify domains of quality, to select and adapt validated instruments for measurement within each domain, to pilot test a data collection process, and to develop an operational quality profiling report format for LTC facilities. DESIGN AND METHODS: Using an expert panel and the LTC research literature, an operational measurement tool was developed, consisting of four domains of quality: organizational, clinical, environmental, and social. DISCUSSION: A pilot study conducted in two nursing facilities demonstrated that the data collection process could be operationalized within tight resource and budgetary constraints. The development of an operational quality assessment tool enables management to take a consistent view of diverse institutions, focusing in detail on quality of care as it is perceived by residents. The tool allows evaluation of trends over time and comparison to external norms.