Precision equipment for symmetrical bending— Part 1. The loading system

The design and performance of precision bending equipment for testing straight beams with constant rectangular section under a pure bending moment is described. Part 1 deals with the loading arrangements and Part 2 with the rig for measuring beam deflection. The methods for recording deflection of strain gauges applied on the beam have been described elsewhere.^1–4
The reactions to the deadweight gravity loads are taken via ball bearings. The total bending moment inaccuracy, i.e. the sum of estimated systematic errors and random errors, the latter expressed as the 2Ga confidence interval about the mean (2G_cim), is about ± 25 x. 10^-4%, for 23 tests with a steel beam with 15 mm × 75 mm cross sectional dimensions, loaded to 1-1.5 mm/m strain.
The measuring rig stands on the beam via hardened and polished spherical segment feet and uses a capacitive transducer system with less than 5nm resolution. Various application tasks are described. The total inaccuracy of the measured deflection, i.e. apart from bending moment inaccuracy, is about ± 35 times 10^4% for about 10 reproduced, not repeated, tests with the same steel beam. The deflection for such a beam is of the order of 2 to 4 mm.     

二厘米微波衰减标准装置不确定度的验证

采用传递比较法对二厘米微波衰减标准装置不确定度进行了验证。测量标准装置的重复性以组内实验标准偏差sn(A)定量表征，测量标准装置的稳定性用组间实验标准偏差sm定量表征。     

戊二醛含量测定方法的改进

对戊二醛测定方法进行改进 ,采用酸度计判定终点的方法代替用肉眼观察指示剂变色来判定终点。改进后的方法平均偏差为 0 .0 4,标准偏差为 0 .0 2。并且在正常情况下 (试样无色 ,含量≥ 1% ) ,改进前后的测试方法的数据结果基本一致。而当试样含量≤ 1%或试样有色时 ,则测试结果相差很大。     

时移地震非一致性影响研究与互均衡效果验证

用地震子波对时移地震非一致性造成影响进行了模拟。将影响因素概括为4种形式，即时移、相位变化、振幅量级不一致，频宽不一致。采用互均衡技术对以上4种情况进行校正，达到了理想的效果。为实际资料的处理和方法研究奠定了理论基础。     

基于信息熵度量的高斯尺度空间角点检测算法

图像的多尺度表示是指从原始图像出发,导出一系列越来越平滑、简化的图像,这种简化意味着图像信息的丢失。图像角点是图像的一个重要的局部特征,本文结合尺度空间理论,实现了多尺度下Harris角点检测,并利用信息熵计算每一尺度下图像的信息量,信息熵是衡量不同尺度下图像信息的可靠方法。通过实验对提取出的特征点进行攻击,证明了这些点具有很好的鲁棒性,与单尺度Harris角点检测相比,该特征点具有更高的重复率,即尺度不变性。     

Erosion-corrosion investigation of high chromium cast irons using newly designed jet type tester

A jet type erosion-corrosion tester was developed for the erosion-corrosion investigation of high-chromium cast irons. During tests the size and the shape of particles in the slurry can be maintained stable. The jet velocity and attack angle can be accurately controlled. The repeatability and ranking consistency of the test results are satisfactory. The test parameters can be adjusted in a wide range, so that the tester can simulate various practical working conditions. Electrochemical test data can be automatically collected and processed. Dynamic polarization curves can be obtained during erosion-corrosion test, which can be used to study the dynamic corrosion characteristics.Two high chromium cast irons were studied in hot concentrated alkaline slurry. The results show that the erosioncorrosion mass loss rate and dynamic corrosion rate of 295Cr26 iron is lower than that of 185Cr13 under the conditions similar to alumyte processing. The mechanism of erosion-corrosion of 295Cr26 and 185Cr13 was studied by using the tester. The interaction between erosion and corrosion was also quantitatively evaluated.     

基于铁基非晶薄带巨磁阻抗效应的位移传感器

利用铁基非晶薄带的特性研制了一种新型的非接触位移传感器.介绍了铁基非晶薄带的磁敏特性、处理方法及位移传感器电路的设计,并对传感器的特性进行了测试.结果显示:所设计的位移传感器重复性好,最大偏差为0.2973％、迟滞小,最大为0.6526％.     

A Modified Region Approach for Multivariate Measurement System Capability Analysis

Measurement system capability analysis is to determine whether the measurement system is capable for use in quality control. The existing research has been extended from univariate to multivariate cases. Two approaches, the multivariate analysis of variance (MANOVA) and the weighted principal components (WPC), were advocated in literature. The MANOVA method is constructed based on the volume ratio that treats the volume of constant‐density contours as the variability estimations. However, it ignores the fact that the relative position change of multivariate measurement errors could affect the measurement system capability. The WPC method uses dimension reduction to reduce the complexity but is unable to build the precision‐to‐tolerance ratio because it does not include tolerance. In this paper, we propose a modified‐region‐based method to compute the precision‐to‐tolerance ratio, the percent of repeatability and reproducibility, and the signal‐to‐noise ratio. This method also incorporates the variance–covariance structure of the measurement errors when dealing with the constant‐density contours of tolerances, total variation, and process variation. The performance of the modified‐region‐based method is evaluated based on a dataset from the literature and a set of relevant simulation. The proposed method proves to be effective compared with other methods.Copyright © 2014 John Wiley & Sons, Ltd.     

Reference Range Estimation: Accounting for Measurement System Errors

Reference range is a statistic that is used in health related fields to represent the range of the most likely values for a variable of interest. Based on this range, individuals are classified as being healthy or unhealthy. In biostatistics, the reference range is calculated as the (1 ? α)% prediction interval, where this prediction interval is based on the estimated population variance from the data. Such estimation of population variance is not precise, because obtained test results do usually have errors associated with them. These errors are due to the imprecise test procedure or gauge used. In this paper, the total variability in the data is decomposed into two categories. The first is the patient‐to‐patient variability and the other is the variability due to the measurement system used. Estimation of the two kinds is performed through a gauge repeatability and reproducibility study, then the reference range is calculated, taking into account only the patient‐to‐patient variability. The revised reference range procedure is illustrated through a case study of vitamin B12 test results. A closed form formula is given to calculate the probability of a given test result being within the revised reference range. Copyright © 2015 John Wiley & Sons, Ltd.     

沉淀分离-络合滴定法测量硫化钠含量

介绍了ZnS沉淀分离-EDTA络合滴定法测量工业硫化钠中Na2S含量的原理和方法，并对该方法的准确性和重现性进行了论证．实验结果表明：该方法具有良好的重现性，重复实验的相对标准偏差为0．55％；该方法具有较高的准确性，与碘量法（国标）相比结果相差0．11％，一致性达到99．5％．