基于定量体视学的颗粒群特征分析

应用图像分析仪和定量体视学原理，对颗粒群特征参数进行了定量分析，并对图像分析的实验参数：最小样本数、图像优化及灰度阈值等进行了讨论研究。实验结果表明，定量体视学图像分析方法可同时获得煤矿渣细粉试样的级配和颗粒形状因子（圆度）等一系列颗粒群特征参数。     

数字图像技术辅助陶瓷显微组织定量分析研究

以古瓷釉显微组织为例,利用显微图像各组元的灰度特性,运用数字图像技术中的图像滤波、图像分割、轮廓提取方法对显微组织图像进行预处理,获取瓷釉组元分离图.在系统构成的基础上,结合体视学方法,对显微组织体积密度(Vv)、表面积密度(Sv)等体视学参数进行计算机分析与测量,为研究陶瓷材料及陶瓷内在结构与外观关系提供了可靠的技术支持和数据基础.     

Mapping of preform architecture for textile reinforced composite products

In this paper, a technique is developed to map the internal fabric preform structure of textile composite products. This technique is based on physical serial sectioning of the composite product. Image analysis and manual yarn recognition are used to identify yarn location in each section. Image stereology is utilized to reconstruct the fabric preform in 3-D space. Data regarding average yarn orientation throughout the composite part are then extracted. This technique is applied to map the internal fabric preform structure of a proprietary textile reinforced composite product. Experimental work points to locations of fabric distortions that occur during the composite product manufacture. This technique could be extended to evaluate the effect of these distortions on the final composite properties.     

Design-based stereology to quantify structural properties of artificial and natural snow using thin sections

The quantification of the structural properties of snow is traditionally based on model-based stereology. Model-based stereology requires assumptions about the shape of the investigated structure. Here, we show how the density, specific surface area, and grain boundary area can be measured using a design-based method, where no assumptions about structural properties are necessary. The stereological results were also compared to X-ray tomography to control the accuracy of the method. The specific surface area calculated with the stereological method was 19.8 ± 12.3% smaller than with X-ray tomography. For the density, the stereological method gave results that were 11.7 ± 12.1% larger than X-ray tomography. The statistical analysis of the estimates confirmed that the stereological method and the sampling used are accurate. This stereological method was successfully tested on artificially produced ice beads but also on several snow types. Combining stereology and polarisation microscopy provides a good estimate of grain boundary areas in ice beads and in natural snow, with some limitations.     

定量金相分析算法及实现

对定量金相学与体视学中所规定的最常用的几个守形参数的实验方法及计算机模拟实验方法的算法分别加以描述,实际应用表明,该算法具有速度快,精度高的特点。     

Stereological analysis of pore structure

A review is given of the basic equations of stereology. These enable the porosity, specific surface, and variously-defined mean pore sizes to be determined from measurements performed on plane sections cut through a porous material. The distribution of pore sizes can only be determined if further assumptions are made. On the other hand, stereology provides the best means of assessing pore shape and the average curvature of the solid, and the only means of determining pore sizes too large for measurement by other methods.     

材料显微组织分析的研究

阐述了应用图像处理技术与定量体视学的原理来实现材料显微组织的定量分析,主要包括系统构成、图像处理与分析的主要步骤、常见显微特征参数的测量和误差分析,并讨论了该研究领域的发展趋势。结果表明,利用计算机图像分析技术实现显微组织的分析具有实用性、先进性和广阔的应用前景。     

古瓷釉显微结构定量分析与实现

以陶瓷釉复相显微结构为研究对象,针对其显微结构各组元灰度值的差异,利用分离图像的方法来将图中各组元分离开来,采用体视学方法对陶瓷釉的各相参数进行分析,并对釉中各相体积分数、空间尺度分布进行定量表征,为古陶瓷的研究与应用提供科学依据.     

Discrimination and mapping of phase distributions by automated crystal orientation measurement

Abstract

Automated crystal orientation measurement/mapping (ACOM) in the SEM enables a fast phase discrimination and the automated acquisition of phase distribution maps at submicrometre resolution, if the phases belong to different Laue groups or if their lattice constants are at least significantly different. The database can further be used for quantitative determination of phase contents, phase boundary characterisation, and mesoscale texture analysis for each phase, such as crystal orientation mapping (COM), texture analysis (orientation density function, pole figures, misorientation distribution function), characterisation of grain and phase boundaries, and orientation stereology.     

Stereological measurement of the specific surface area of seasonal snow types: Comparison to other methods, and implications for mm-scale vertical profiling

Density and specific surface area (SSA) are fundamental parameters determining the physical and chemical properties of porous materials like snow. The SSA of snow can be measured directly, using stereology, gas adsorption techniques, X-ray micro-tomography, or indirectly by optical methods deducing the SSA from the snow reflectance. Traditional stereological methods are unbiased only for convex shapes and isotropic snow. We applied new design- and model-based stereological principles, combined with digital image processing, to measure SSA without bias. The new approach only requires vertical sections and a simple, specific sampling design to estimate the SSA of snow. The SSA of thirty snow samples covering all typical snow types and a wide range of density was analyzed using micro-tomography and unbiased stereology. The results show that the SSA of all snow types, even of very complex shape, can be determined with very high precision. The SSA values determined using gas adsorption, X-ray micro-tomography, and stereology were directly compared. They were highly correlated and no systematic deviation was found between these methods. We show that the density and SSA of vertically inhomogeneous and finely layered snow can be analyzed precisely using this new technique. The technical requirements are modest compared to other methods, with similar or better precision. We suggest that this stereology-based method can be the laboratory method of choice to analyze density and SSA of snow in layered samples.     

Quantification of particle morphologies in view of quality control of the thermal spray process

The relationships between processing parameters, deposit microstructures, and deposit properties are not well understood, mainly due, on the one hand, to the numerous parameters governing the thermal spray process and, on the other, to the random mode of deposition of the material (for example, individual impacts of molten particles). The interactions are mainly related to the impact, spreading, and solidification of the material droplets onto the substrate, or previously deposited layers. A methodology was implemented to quantify individual splat morphologies using size and shape factors referring to an equivalent diameter, an elongation factor, and a degree of splashing, and also three-dimensional profilometry and stereology. This approach is mainly based on the use of an image analysis system and statistical tools. A few examples of the potential of this method are given. Such a lowcost and low-time-consuming protocol could be easily implemented for an optimization purpose.     

Optimization of structural dynamic behaviour based on effective modal parameters

Optimization of complex structures often leads to high calculation costs. Indeed, the structure has to be frequently reanalysed in order to update the optimization criteria. We propose an optimization method based on effective modal parameters. These parameters are close to the modal matrices used for the modal analysis of a structure. Thus, once the structure has been analysed, it becomes very easy to calculate optimization criteria. First, we will explain the modal analysis that we will use in this paper. A modal model will be used to analyse the hollow parts of the structure. The modal analysis of the whole structure will be performed using substructuring and ‘double modal synthesis’ proposed by Jezequel. Secondly, we will explain how to obtain effective modal parameters and their use for optimization. Finally, we will show the efficiency of these parameters through the optimization of a complex structure, using two types of optimization methods. Copyright © 2006 John Wiley & Sons, Ltd.     

广义检波解调分析的三种算法及其局限性研究

针对广义检波滤波解调分析的局限性给机械故障诊断带来的误诊断问题 ,系统研究了广义检波滤波解调分析基本原理和局限性的产生原因 ,指出混频现象的产生主要是由于取绝对值、检波过程或平方计算过程都可能产生混频效应 ,在解调谱中出现为无法分析的频率成分 ,给分析带来很大困难。并由此推导了避免混频现象的采样频率的选取范围 ,从而根本上避免了此类误诊断的产生。所得出的结论为具有齿轮、滚动轴承等设备的机械故障诊断提供了理论参考。     

Review paper – stereology: Historical perspective and applicability to concrete technology

This article presents clear evidence of old roots of stereology. Although the connotation “stereology” dates back 40 years, the discipline is still a newcomer. It is founded on the solid rock of famous, well-accepted theorems, of which those of Cavalieri, Buffon and Cauchy are mentioned as leading examples. Additionally, the article shows the direct link to modern stereological methodology. The latter is available for reliable and economic assessment of relevant features of the structure of cementitious materials as obtained by laboratory experiments.     

PLZT 透明铁电陶瓷晶粒长大的体视学研究

本工作用热压 8/65/35 PLZT 陶瓷为原始材料,通过不同热处理过程制备出各种不同晶粒度的陶瓷试样,试样经过热腐蚀后,用 Cambridge Instruments Ltd 的 Quantimet 900对它们进行图像分析和定量体视学研究,获得了很有价值的各种数据。     

铝合金熔焊区结构稳定性的测试技术

在航空航天领域中,轻合金激光熔焊区的结构稳定性具有重要意义.因此,本文从晶界面结构视角具体审视这一问题.本研究以一种5系铝合金的激光熔焊区为研究对象,分别利用扫描电镜、电子背散射衍射(EBSD)和统计性的晶界面结构分析方法,首先实现了热影响区、等轴区和熔合区在空间上的准确划分;其次对各子区分别计算了穿过晶界面的取向差角...     

RIFIT: analyzing hardware and software in safeguarding systems

Currently many systems used to safeguard processes in industry use a combination of hardware and software. Many of the analysis techniques applied in this field, however, quantify aspects of hardware only. This paper presents a technique that is used to quantify the safety of safeguarding systems as a whole, including hardware and software. The techniques used bases itself on a combination of simulation and fault injection techniques. This paper will present this new technique and will demonstrate that it is possible using this “Random Intelligent Failure Injection Technique” to analyze and optimize practical safeguarding systems.