油水两相流浓度电容层析成像的测量方法

以8电极油水两相流电容层析成像系统为研究对象,分析了油水两相流电容层析成像系统的测量原理,依据二重积分微元原理建立了油水两相流相浓度分布信息的数学模型,采用ART图像重建的方法完成油水两相流的浓度测量,并在重建算法中引入了阈值以提高图像重建质量和含率计算的准确性,测量误差在1%左右,较好地解决了其他测量方法速度慢,成本高,安全性差等缺陷,为油水两相流浓度的测量提供了一种新方法.     

基于螺旋式电极的两相流相关流量测量研究

以气/固两相流互相关测量系统为研究对象,采用计算机仿真的方法,对由电容传感器构成的基于离散相浓度的电容互相关流速测量机理进行研究.利用ANSYS软件分析电容传感器与离散相浓度的关系;采用Monte-Carlo方法,建立气/固两相流动模型;研究"凝固流动图型"、"非凝固流动图型",离散相浓度、粒度及速度分布对互相关测量系...     

HfB2-SiC-HfC陶瓷相组成与相成分定量分析的对比研究

以两种不同WC含量、不同球磨介质的无压烧结HfB₂-SiC-HfC超高温陶瓷为研究对象, 对比了两套集成式相组成和相成分定量分析方法, 发现基于X射线衍射和扫描电镜分析的HfB₂、SiC和HfC相组成和固溶度测量结果相互符合, 都适用于复相陶瓷的综合性定量分析。基于扫描电镜的分析还进一步发现和测量出痕量WB相的含量; XRD-K值法被成功应用于测量固溶度低的相组成。两个对比样品的定量分析结果表明: 烧结助剂含量和球磨介质的改变都不影响W在HfB₂和HfC相中的固溶度, 支持了反应致密过程中液相起关键作用的观点; SiC球磨会造成W的损失, 因此Si₃N₄是更合适的球磨介质。     

基于RPCA及低秩表示的气液两相流动图像中气泡图像分离研究

气液两相流中对气泡的测量研究是非常重要的,气泡测量技术中,如何实现气泡与背景分离是研究的重点问题。现有的测量技术大多采用图像二值化、边缘检测、图像滤波等方法来实现气泡信息的提取,而这些测量方法往往是存在不足的,仅仅针对单一图片或者需要人为手动选取。本文通过SVD（单值分解）和RPCA（鲁棒主成分分析法）对气液两相流中的气泡图像进行背景分离,其方法主要有两个特点：连续相关性和自动获取性。并提出逐行累加和逐列累加的方法,测量气泡的运动过程形态。研究表明,相比于原始的图像分离技术,利用RPCA运算,对气泡的定位、大小和速度表示都更准确。     

液固两相流声发射检测系统设计及实验评价

液固两相流参数实时测量对生产过程控制和可靠运行具有重要意义。针对现有液固体系中检测固相颗粒方法上的缺陷,研制开发了液固两相流声发射检测系统,并进行室内评价试验。该系统利用自行设计的声发射检测仪表采集液固两相流中砂粒的声发射信号,编写了专门的计算处理软件,在实验室条件下提取不同砂粒粒度和浓度的声发射信号特征。结果表明,砂粒粒度和浓度均与功率谱幅值有良好的相关性,该系统能有效检测浓度达0.2%以上,粒度100目以上的砂粒。     

基于电容层析成像系统测量信号稀疏性的两相流流型辨识

提出了基于电容层析成像(ECT)测量电容信号稀疏性的两相流流型辨识算法,该算法首先使用所有流型对应的归一化测量电容值信号构建一个过完备字典,并将待辨识样本通过该过完备字典进行稀疏表示,使其具有稀疏性并满足稀疏重构的基本要求,然后以压缩感知的正交匹配追踪(OMP)算法求取各标准样本对应于完备样本集的稀疏解,最后根据待辨识样本与标准样本稀疏解之间的线性相关程度进行流型辨识。使用该方法对5种典型的两相流流型识别进行了仿真及实验研究,结果表明:该方法的流型正确识别率均高于98%。     

超声谱法在颗粒两相流测量中的应用进展

颗粒两相流测量技术指对连续相中的颗粒粒度和浓度等参数进行测量,是两相流测量中非常重要的分支。它与化工、能源、动力、材料、食品等诸多行业都有着密切联系,随着近年来工业的高速发展,颗粒两相流测量技术获得越来越多关注。结合近几年超声谱法在颗粒测量中的研究现状,重点回顾超声谱法颗粒两相流测量技术的应用进展状况,并分析其发展前景。     

固相微萃取及主成分分析用于潲水油GC-MS指纹图谱的分析

采用固相微萃取法提取来自19个潲水油样品的挥发性成分,并通过气相色谱质谱联用法得出各样品共有的12种共有成分,以12种共有成分为分析变量,运用主成分分析法对19个样品进行主成分分析.结果表明,原潲水油指纹图谱的12维参数可用4个主成分来描述,说明主成分分析用于潲水油挥发性成分指纹图谱的数据分析是可行的.且利用主成分投影分析对样品进行归类和鉴别,能有效地区分潲水油与正常油.     

激光多普勒流动测量技术在颗粒流体两相流中的应用

分析介绍了激光多普勒流动测量技术的原理和用LDV／PDPA同时测定颗粒流体两相速度和粒径大小的基本方法，并进一步讨论了用LDV／PDPA测量颗粒浓度和两相流动动态特性的问题。     

Cu-15Ni-8Sn合金的调幅相结构

利用透射电镜研究了Cu-15Ni-8Sn合金调幅相的显微结构和相变动力学.发现合金在完全淬火状态下,调幅分解迅速,调幅分解之后发生有序化.有序相具有DO22结构,由粗化的调幅组织转变为有序相的三种变体.分析有序化出现在调幅分解之后的原因是有序化需要的溶质原子浓度高于溶质原子的平均浓度,需要借助于调幅分解的成分起伏来达到.并推测有序相的形貌为针状.     

Liquid-phase mass transfer in high-pressure systems with a supercritical and a liquid phase

Liquid-phase diffusion coefficients and mass-transfer coefficients were measured in binary two-phase systems at high pressures. Both were determined from the rates of absorption of the gaseous component into the liquid. Diffusion coefficients were measured by observing unsteady-state diffusion into a sell) i infinite liquid phase and fitting transient counterdiffusion mass-flow rates to the visually determined change of the position of the interface between the liquid and the supercritical phase. Mass-transfer coefficients in the liquid phase were determined from the absorption rate of the gaseous component into a falling liquid film of known flow and physical properties. Experiments were performed with the binary systems carbon dioxide-oleic acid, carbon dioxide -methyl myristate, and carbon dioxide-methyl palmitate. Liquid-phase diffusion coefficients rise significantly with concentration as viscosity decreases. Temperature also has a strong effect on diffusivities. Experimental mass-transfer coefficients in nearly saturated liquids agree well with calculations for falling films with known properties, whereas far from equilibrium, Marangoni convection greatly enhances mass-transfer rates. Close to the critical point of the binary system at a given temperature, a sharp decline of the mass-transfer coefficient is observed.     

PAN/PS共混超滤膜的制备及性能研究

采用共混法制备聚丙烯腈(PAN)/聚砜(PS)超滤膜,以聚丙烯腈作为第一组分(连续相),聚砜为第二组分(分散相),用相转化法流延成膜;研究共混比、聚合物浓度、添加剂、凝胶浴等对共混膜水通量和截留率的影响,并采用扫描电镜对膜的结构形态进行了观察。结果表明:PAN/PS共混膜与PAN膜具有相似的化学稳定性,但较PAN膜具有更好的分离透过性。     

汽车尾气成分动态检测技术研究

针对汽车尾气成分动态检测的需要,设计不分光红外检测气室、控制系统及上位机软件,开发出简易瞬态工况检测仪。该控制系统以ARM7为核心,传感器信号经放大、A／D转换等调理后实时显示尾气各成分的浓度并存储。检测仪经USB接口把检测数据传递给工控机,利用上位机软件对各成分浓度、流量进行统计,分析出汽车在各工况的排放等。经实验验证：该检测仪可满足动态检测各工况尾气成分和流量的需要,检测结果直接决定环保标志的发放,方便实用。     

乳状液膜法处理H酸废水的实验研究

以Span-80、FSN-100为复合表面活性剂,TOA为流动载体,研究了乳状液膜处理H酸废水时TOA浓度、内相NaOH浓度、油内比Roi、外相pH、乳水比Rew及搅拌强度等因素对废水COD去除率指标的影响,分析了其内在影响因素的规律性.同时,实验结果表明乳状液膜法处理H酸废水具有较好的应用前景.     

Flow phenomena of superfluid helium through a porous plug phase separator

A porous plug, which separates vapour from superfluid helium (He II), is an indispensable component for space cryogenics. Precise measurement of the temperature distribution inside a number of porous plugs has been successfully carried out to reveal the actual flow phenomena of superfluid helium and the vapour flow through the plugs. It was found that He II flows ideally through the upstream portion of the porous plug, thus the London equation can be applied there. Superfluid helium turns into vapour near the exit of the porous plug. The flow of the normal component of He II remained laminar in the cases examined in the experiment. The liquid-vapour phase boundary was formed just at the exit of the porous plug and moved toward the upstream side as the mass flow rate increased. A thermodynamic consideration of He II phase separation using a porous plug is also presented in this Paper.     

A study on numerical simulations and experiments for mass transfer in bubble mode absorber of ammonia and water

An absorber is a major component in the absorption refrigeration systems, and its performance greatly affects the overall system performance. In this study, both the numerical and experimental analyses in the absorption process of a bubble mode absorber were performed. Gas was injected into the bottom of the absorber at a constant solution flow rate. The region of gas absorption was estimated by both numerical and experimental analyses. A higher gas flow rate increases the region of gas absorption. As the temperature and concentration of the input solution decrease, the region of gas absorption decreases. In addition, the absorption performance of the countercurrent flow was superior to that of cocurrent. Mathematical modeling equations were derived from the material balance for the gas and liquid phases based on neglecting the heat and mass transfer of water from liquid to gas phase. A comparison of the model simulation and experimental results shows similar values. This means that this numerical model can be applied for design of a bubble mode absorber.     

The effect of material flow on the stress analysis of an SMC component

Recent published work concerning the manufacture of composite components from compression moulded sheet moulding compound suggests that an analysis of the compression moulding process should be performed before a structural analysis of the component. The flow of the material during the manufacturing process has been shown to cause significant variations in fibre orientation and concentration, hence effecting the resultant mechanical properties. Commerical software is now available to analyse the compression moulding process, however, such software represents another step and investment in the design-manufacture cycle. This paper studies the possible effect of material flow upon the analysis of a composite component manufactured from sheet moulding compound. The analysis concludes that for the component considered here, the effect of the material flow was not significant.     

Generation of a function-component-parameter multi-domain matrix from structured textual function specifications

This study introduces a method to build a multi-domain matrix (MDM), visualizing the intended architecture of a system within the component, function, and parameter domains. The MDM is generated from textual function specifications that are subject to a specific grammatical structure and vocabulary based upon the functional basis and interaction basis as presented in the literature. Two types of functions are distinguished: functions specifying what functionality a particular component provides to another component, and functions specifying the internal working (transformation of flow) of a particular component. The fixed grammar for the specification of the two types of functions allows for the automated derivation of dependencies between components, between functions of components, and between system parameters. A case study on a navigation lock demonstrates that the system architecture generated from function specifications matches the architecture of the real lock system fairly well. As such the method can be used in the early design phase to reveal the product architecture that is embodied in the function specifications of system components. The method may also support modeling of high-definition DSMs of existing engineering systems.     

气/固两相流固相浓度传感器的研究

设计了一种新型测量气／固两相流固相浓度的螺旋极板电容传感器，并通过实验得出提高传感器检测场灵敏度空间分布均匀性及克服边缘效应对检测精度影响的方法。     

On‐Site Formation of Emulsions by Controlled Air Plugs

Air plugs are usually undesirable in microfluidic systems because of their detrimental effect on the system's stability and integrity. By controlling the wetting properties as well as the topographical geometry of the microchannel, it is reported herein that air plugs can be generated in pre‐defined locations to function as a unique valve, allowing for the on‐site formation of various emulsions including single‐component droplets, composite droplets with droplet‐to‐droplet concentration gradient, blood droplets, paired droplets, as well as bubble arrays without the need for precious flow control, a difficult task with conventional droplet microfluidics. Moreover, the self‐generated air valve can be readily deactivated (turned off) by the introduction of an oil phase, allowing for the on‐demand release of as‐formed droplets for downstream applications. It is proposed that the simple, yet versatile nature of this technique can act as an important method for droplet microfluidics and, in particular, is ideal for the development of affordable lab‐on‐a‐chip systems without suffering from scalability and manufacturing challenges that typically confound the conventional droplet microfluidics.