软测量技术在多相流检测中的应用

本文综述了软测量技术在多相流检测中的应用.在简要阐述软测量技术基本原理和特点的基础上,介绍了基于机理分析、人工智能、过程层析成像和动态信号分析等多相流检测领域中的软测量方法,并分析了目前该技术应用中存在的问题.     

纸浆浓度的在线测量方法与研究展望

本文介绍了纸浆浓度参数的特殊性、测量的重要性、现有的纸浆浓度在线测量方法和特点，并从计算机技术应用和多相流测量技术发展的角度，展望了纸浆浓度在线测量的研究方向。     

磁共振多相流在线计量装置现场试验分析

针对地面油气多相流的实时准确计量需求，介绍了一种磁共振多相流在线计量装置。通过现场试验验证，该计量装置能够高效、准确地计量油气水多相流，具有绿色、高效、准确的技术优势，可实现无人值守计量，能够很好地替代三相分离器完成油气多相流的地面计量工作。     

Halbach阵列核磁共振多相流传感器参数优化与仿真

基于核磁共振的多相流测量,能有效克服传统多相流测量方法的局限性,是目前多相流研究领域的新方向。文中基于永磁阵列磁场理论,以磁通密度和均匀性为参数优化目标,采用COMSOL有限元软件进行Halbach磁体传感器的设计与仿真。仿真和理论分析表明,永磁源内外径比、组装块数、磁性材料是影响Halbach磁体性能的主要因素。本文针对2″油管的核磁共振多相流测量,优化和设计Halbach阵列参数,最终形成了性能优越、适用于2″油管的Halbach阵列传感器,解决了核磁共振多相流动态在线测量的重要技术问题。     

12电极电容层析成像系统的设计

电容层析成像技术(ECT)是基于电容敏感原理的过程层析成像技术(PT).它可进行多相流的相浓度、流型、流量等参数的在线测量,是目前最具发展前景的多相流参数检测方法.本文以12电极电容层析成像系统为研究对象.主要介绍一种基于交流激励型的电容层析成像的C/V转换电路,并分析了该电路的工作原理.该电路能抑制杂散电容的干扰,能...     

油田多相流计量方法研究与探讨

分析了多相流分离计量和在线计量方法,总结了多相流计量的核心技术和研究进展,分析了弯管流量计测量油水和气水两相流实验数据,结果表明弯管测量油水两相流准确性较好,测量气水两相流误差较大.探讨了弯管流量计与密度计或与其它流量计配合的测量方案.     

电容法多相流检测中相浓度的求解

从对电容传感器的有限元（FEM）分析及仿真入手,提出了求解油、水、气三相流相浓度的插值计算方法,并实现了三相流的定量测量。该方法所需测量参数少,便于实时、在线、连续和非侵入地检测石油多相流中各组分的含量。     

多传感器数据融合技术在多相流参数测量中的应用

对于多相流动系统,由于多传感器系统比单传感器具有优越性,所以,数据融合技术在多相流参数检测领域的应用越来越受到关注.对多传感器数据融合技术作了回顾,介绍了多传感器数据融合技术在多相流参数检测,如流型辨识、多相流流体界面分布成像等方面的应用情况,并对这项技术在多相流参数检测方面所面临的挑战和前景作了分析.     

气-液两相流空隙率的测量方法

两相流或多相流参数的测量在各种生产过程和能源系统中愈来愈引起人们的重视。例如,在工业系统和实验室研究中,有时需对下列对象进行测量:油田开采中油一气流量,悬浮液管道,物料的气体输送,流化床,化学反应器,脱盐装置,地热能站,核反应器等。这些测量都涉及到了多相流问题。毫无疑问,多相流参数的测量在各个领域的应用都是很重要的。在与核反应有关的研究中,对多相流参数检测技术的发展起了相当的推动作用。这里不仅仅是为了获取稳态操作下的设计信息,同时也是为了在过渡状态和事     

多相流分相含率检测

介绍了基于双能射线对油气水多相流分相含率的测量机理及系统构成 ,通过对射线穿过原油的透射计数 ,并对各种误差进行补偿、修正 ,从而实现对多相流分相含率的在线测量     

Analysis of the Rk surface roughness parameter proposals

European manufacturers have proposed a set of surface roughness parameters based on an examination of the variation in slope of the bearing ratio curve of a surface profile. It is shown, that the proposed procedure provides no useful information, and indeed is misleading, since the bearing ratio curve of even a normally-distributed random surface profile exhibits the expected variation in slope when plotted on rectangular coordinates. On the other hand, the desired information is readily obtained by a similar examination of the cumulative height distribution of a surface profile (the unity complement of the bearing ratio) when it is plotted on normal probability coordinates.     

A vectorial method using combination theory in the term 2Wi × Vrel to calculate the acceleration of a point in the space kinematics of rigid bodies

This study to calculate the acceleration of a point using combination theory for compound accelerations constitutes a new interpretation of the general relative acceleration equation. The advantages of this new approach are the easy tabulation and the simple order of the solution and the preservation of the physical concepts. Also, the student has the opportunity to distinguish between $\text{2w}{}_{\mathrm{i}}\text{× V}{}_{\mathrm{<mtext>rel</mtext>}}\text{and}\text{2W × V}{}_{\mathrm{P/M}}$, the Coriolis acceleration. This distinction is useful in avoiding an erroneous physical interpretation.     

Investigation on the impact behavior of Al2O3-SiC-MgO nanoceramic/metal laminated composite

Lightweight laminated composites containing a ceramic front layer and a metallic backing layer were used in order to protect people, moving equipment, and mobile vehicles from high velocity impact and the increased mobility of mobile vehicles. In this study, by adding10 vol% SiC and 500 ppm MgO nanoscale particles on the microstructure of Al ₂ O ₃ matrix and applying optimum sintering conditions, ceramic performance against high-speed projectile impact was improved. To perform this investigation, a number of target samples with two different types of front layers (alumina and Al ₂ O ₃-SiC-MgO nanocomposite ceramic) were produced. Impact tests were conducted on these samples using 7.62 mm projectiles with a velocity of 820 ± 15 m/s. The amount of bulge and bending of the backing layer caused by impact tests was measured. The results of the impact tests on the samples made of Al ₂ O ₃-SiC-MgO nanocomposite ceramics and alumina were also compared and analyzed. The results indicate that the substitution of Al ₂ O ₃-SiC-MgO ceramic layer — which is proffered in this paper — instead of pure alumina ceramic layer, decreases the areal-density of the samples by at least 30% and improves mechanical properties by about a 60% increase in flexural strength and 100% growth of the energy distribution factor, which impressively increases impact energy absorption.     

面向中小型企业的CAD/CAPP/PDM/ERP集成技术的研究

阐述了PDM与CAD／CAPP及PDM与ERP的集成模式;讨论了面向中小型企业的CAD／CAPP/PDM／ERP集成技术,并在面向中小型企业的PDM系统的开发过程中实现了本文提出的方法。     

弹头冲击盔-头-颈的数值模拟和运动仿真

这里根据盔-头-颈的结构特点建立了简化的有限元分析模型。利用LS—DYNA3D模拟了弹头冲击头盔时，头部加速度和速度的动态响应特性和颈部的受力过程。并在多参数条件下，对头、颈部的伤害进行了简单的评价。这里所采用的计算方法和模拟结果有助于头颈部组织损伤机理的分析研究，并为头盔内衬结构的优化设计和改进提供了理论参考。     

Chemical reactions and morphological stability at the Cu/Al2O3 interface

The microstructures of diffusion‐bonded Cu/(0001)Al₂O₃ bicrystals annealed at 1000 °C at oxygen partial pressures of 0.02 or 32 Pa have been studied with various microscopy techniques ranging from optical microscopy to high‐resolution transmission electron microscopy. The studies revealed that for both oxygen partial pressures a 20–35 nm thick interfacial CuAlO₂ layer formed, which crystallises in the rhombohedral structure. However, the CuAlO₂ layer is not continuous, but interrupted by many pores. In the samples annealed in the higher oxygen partial pressure an additional reaction phase with a needle‐like structure was observed. The needles are several millimetres long, ～10 µm wide and ～1 µm thick. They consist of CuAlO₂ with alternating rhombohedral and hexagonal structures. Solid‐state contact angle measurements were performed to derive values for the work of adhesion. The results show that the adhesion is twice as good for the annealed specimen compared to the as‐bonded sample.     

Near-field second harmonic imaging of the c/a/c/a polydomain structure of epitaxial PbZrxTi1–xO3 thin films

Near-field optical second harmonic microscopy has been applied to imaging of the c/a/c/a polydomain structure of epitaxial PbZr _x Ti_{1– x} O₃ thin films in the 0 <  x  < 0.4 range. Comparison of the near-field optical images and the results of atomic force microscopy and X-ray diffraction studies show that an optical resolution of the order of 100 nm is achieved. Symmetry properties of the near-field second harmonic signal allow us to obtain good optical contrast between the local second harmonic generation in c- and a-domains. Experimentally measured near-field second harmonic images have been compared with the results of theoretical calculations. Good agreement between theory and experiment is demonstrated.     

About the role of the various types of secondary electrons (SE1; SE2; SE3) on the performance of LVSEM

The relative weight, δ_Β, of the yield of secondary electrons, SE₂, induced by the backscattered electrons, BSE, with respect to that, δ_P, of secondary electrons, SE₁, induced by the primary electrons, PE, is deduced from simple theoretical considerations. At primary energies E₀ larger than E_M (where the total SE yield δ = δ_P + δ_B is maximum), the dominant role of the backscattering events is established. It is illustrated in SEM by a direct comparison of the contrast between SE images and BSE images obtained at E₀ ～ 5 keV and E₀ ～ 15 keV on a stratified specimen. At energies E₀ less than E_M, the dominant role of SE₁ electrons with respect to SE₂ (and SE₃) is established. It is illustrated by the better practical resolution of diamond images obtained with an in‐lens detection in low voltage SEM E₀ ～ 0.2–1 keV range compared with that obtained with a lateral detector. The present contribution illustrates the improved performance of LVSEM in terms of contrast and of practical resolution as well as the importance of variable voltage methods for subsurface imaging. The common opinion that the practical lateral resolution is given by the incident spot diameter is also reconsidered in LVSEM.     

SiC／Fe／SiC连接件高温温度场分布的计算

采用有限元方法对SiC／Fe／SiC高温钎焊连接件进行了三维温度场分布的有限元计算分析,以期对该连接件热力耦合条件下的应力分析提供热分析结果,计算表明,在连接件的边界、棱角处由于其曲率半径的影响,使得该区域具有较高的自由能,温度较其他区域高。     

Electron and light microscopy studies on the domain structures of Zn3B7O13Cl, Zn3B7O13Br and Zn3B7O13I ferroic boracites

The domain structures of Zn₃B₇O₁₃Cl, Zn₃B₇O₁₃Br and Zn₃B₇O₁₃I boracite single crystals were studied by means of polarized light in conjunction with electron microscopy. Single crystals of the three compositions were grown by chemical transport reactions in closed quartz ampoules, at a temperature of 900 °C and were examined by polarizing optical microscopy (PLM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). For both PLM and SEM, the same as‐grown samples were used without having to resort to metallization of the crystal faces. For TEM the single crystals were crushed and mounted on holey carbon films. Comparative electron microscope images were useful for revealing the domain structure of these ferroelectric/ferroelastic materials previously observed between the crossed polars of an optical microscope. X‐ray diffraction analysis of the pulverized crystals was performed for this triad of halogen boracites containing zinc as a common metal.