Summary of ISO/TC 201 Standard XI. ISO 17974:2002—Surface chemical analysis—High‐resolution Auger electron spectrometers—Calibration of energy scales for elemental and chemical‐state analysis

This International Standard specifies a method for calibrating the kinetic energy scales of Auger electron spectrometers for elemental and chemical‐state analysis at surfaces. It is only applicable to instruments that incorporate an ion gun for sputter cleaning. This International Standard further specifies a method to establish a calibration schedule, to test for the kinetic energy scale linearity at one intermediate energy, to confirm the uncertainty of the scale calibration at one low and one high kinetic energy value, to correct for small drifts of that scale and to define the expanded uncertainty of the calibration of the kinetic energy scale for a confidence level of 95%. This uncertainty includes contributions for behaviours observed in interlaboratory studies but does not cover all of the defects that could occur. This International Standard is not applicable to instruments with kinetic energy scale errors that are significantly non‐linear with energy, to instruments operated at relative resolutions poorer than 0.2% in the constant ΔE/E mode or poorer than 1.5 eV in the constant ΔE mode, to instruments requiring tolerance limits of ±0.05 eV or less or to instruments equipped with an electron gun that cannot be operated in the energy range 5–10 keV. This standard does not provide a full calibration check, which would confirm the energy measured at each addressable point on the energy scale and should be performed according to the manufacturer's recommended procedures. Crown Copyright © 2003. Published by John Wiley & Sons, Ltd.     

Summary of ISO/TC 201 standard: XXI. ISO 21270:2004—Surface chemical analysis—X‐ray photoelectron and Auger electron spectrometers—Linearity of intensity scale

This International Standard specifies two methods for determining the maximum count rate for an acceptable limit of divergence from linearity of the intensity scale of Auger and x‐ray photoelectron spectrometers. It also includes methods to correct for intensity non‐linearities so that a higher maximum count rate can be employed for those spectrometers for which the relevant correction equations have been shown to be valid. Copyright © 2004 John Wiley & Sons, Ltd.     

基于HALCON的板料成形网格应变测量系统的实现

随着计算机技术和信息技术的发展,视觉检测技术被引入到板料成形应变测量中。通过基于先进的图像处理软件HALCON,利用双目立体视觉原理,对摄像机进行标定,以获取摄像机的内外参数,并分析图像数量对标定准确度的影响。利用视差原理获得匹配点的三维坐标,根据圆形网格变形后的椭圆长短轴的长度变化,计算真实应变,并分析匹配误差对三维重建的影响,用OpenGL语言将应变可视化;在VC6.0下调用HALCON的算子库编程实现板料成形网格应变测量系统,实验证明该系统在速度、准确度方面能够达到测量要求。     

Linear calibrations in chromatography: The incorrect use of ordinary least squares for determinations at low levels,and the need to redefine the limit of quantification with this regression model

Ordinary least squares is widely applied as the standard regression method for analytical calibrations, and it is usually accepted that this regression method can be used for quantification starting at the limit of quantification. However, it requires calibration being homoscedastic and this is not common. Different calibrations have been evaluated to assess whether ordinary least squares is adequate to quantify estimates at low levels. All calibrations evaluated were linear and heteroscedastic. Despite acceptable values for precision at limit of quantification levels were obtained, ordinary least squares fitting resulted in significant and unacceptable bias at low levels. When weighted least squares regression was applied, bias at low levels was solved and accurate estimates were obtained. With heteroscedastic calibrations, limit values determined by conventional methods are only appropriate if weighted least squares are used. A “practical limit of quantification” can be determined with ordinary least squares in heteroscedastic calibrations, which should be fixed at a minimum of 20 times the value calculated with conventional methods. Biases obtained above this “practical limit” were acceptable applying ordinary least squares and no significant differences were obtained between the estimates measured using weighted and ordinary least squares when analyzing real‐world samples.     

Calibrated Embeddings in the Special Lagrangian and Coassociative Cases

Every closed, oriented, real analytic Riemannian3–manifold can be isometrically embedded as a specialLagrangian submanifold of a Calabi–Yau 3–fold, even as thereal locus of an antiholomorphic, isometric involution. Every closed,oriented, real analytic Riemannian 4–manifold whose bundle of self-dual2–forms is trivial can be isometrically embedded as a coassociativesubmanifold in a G₂-manifold, even as the fixed locus of ananti-G₂ involution.These results, when coupledwith McLean's analysis of the moduli spaces of such calibratedsubmanifolds, yield a plentiful supply of examples of compact calibratedsubmanifolds with nontrivial deformation spaces.     

Measurement of spatial object''''s exterior attitude based on linear CCD

It is difficult to realize real-time measurement of exterior attitude by the traditional systems based on the area image sensor which have conflict between speed and accuracy.The subsystem for three-dimensional (3D) coordinate rcconstruction of point target (S3DCRPT) which is composed of three one-dimensional (1D) cameras based on linear charge-coupled device (CCD) can determine the distant light spots' spatial position. The attitude angle of the measured object is determined by the spatial solution while the coordinate reconstruction is separately carried on by the S3DCRPT with some point cooperation targets (PCTs) on the measured object. A new optical system is designed to solve the interference problem with one-to-one relationship between the PCTs and the S3DCRPT optical subsystems,which improves the measurement accuracy and saves space. The mathematical model of the attitude measurement is established,and partial and global calibrations are realized for the multi-camera attitude measurement system.The test results show the feasibility of the exterior attitude measurement based on linear CCD.     

EFFECTS OF APODIZATION FUNCTION,ZERO FILLING,BACKGROUND SPECTRA,AND ABSORBANCE TRANSFORMATION ON MID-INFRARED CALIBRATIONS FOR FEED COMPOSITION

ABSTRACT

Research has demonstrated that diffuse reflectance mid-infrared spectroscopy can, like near-infrared diffuse reflectance, be used to quantitatively determine the composition of ground samples of forages and soils without the need for KBr dilution. While it has been demonstrated that the accuracy of calibrations developed using mid-infrared spectra can be equal to or better than that achieved using near-infrared spectra, the influence of factors such as apodization function has not been determined. Results based on the spectra of 173 treated forage samples obtained using a DigiLab FTS-60 spectrometer have demonstrated that many parameters associated with mid-infrared spectra have little or no effect on partial least squares calibrations. Additional zero filling of spectra had little effect other than to increase the derivative gaps found to produce optimal calibrations, but calibrations developed using Kubelka-Munk transformed data, as opposed to absorbance data, were not as accurate. Choice of apodization function also had little effect, although slightly better results were found using triangular or weak Norton-Beer. Likewise, the frequency of taking a background spectrum did not seem to have any great effect on calibrations, although results were slightly better with hourly or daily acquisitions as opposed to one for each sample as is done in the near-infrared.     

Volume-Minimizing Foliations on Spheres

The volume of a k-dimensional foliation in a Riemannian manifold Mⁿ is defined as the mass of the image of the Gauss map, which is a map from M to the Grassmann bundle of k-planes in the tangent bundle. Generalizing the construction by Gluck and Ziller (Comment. Math. Helv. 61 (1986), 177–192), ‘singular’ foliations by 3-spheres are constructed on round spheres S⁴ⁿ⁺³, as well as a singular foliation by 7-spheres on S¹⁵, which minimize volume within their respective relative homology classes. These singular examples, even though they are not homologous to the graph of a foliation, provide lower bounds for volumes of regular three-dimensional foliations of S⁴ⁿ⁺³ and regular seven-dimensional foliations of S¹⁵, since the double of these currents will be homologous to twice the graph of any smooth foliation by 3-manifolds.The second author was supported during this research by grants from the Universidade de Sāo Paulo, FAPESP Proc. 1999/02684-5, and Lehigh University, and thanks those institutions for enabling the collaboration involved in this work.Mathematics Subject Classifications (2000). 53C12, 53C38.     

Magnetic field-induced martensitic phase transformation in magnetic shape memory alloys: Modeling and experiments

In this work, a continuum based model of the magnetic field induced phase transformation (FIPT) for magnetic shape memory alloys (MSMA) is developed. Hysteretic material behaviors are considered through the introduction of internal state variables. A Gibbs free energy is proposed using group invariant theory and the coupled constitutive equations are derived in a thermodynamically consistent way. An experimental procedure of FIPT in NiMnCoIn MSMA single crystals, which can operate under high blocking stress, is described. The model is then reduced to a 1-D form and the material parameter identification from the experimental results is discussed. Model predictions of magneto-thermo-mechanical loading conditions are presented and compared to experiments.     

Non-linear calibration models for near infrared spectroscopy

Different calibration techniques are available for spectroscopic applications that show nonlinear behavior. This comprehensive comparative study presents a comparison of different nonlinear calibration techniques: kernel PLS (KPLS), support vector machines (SVM), least-squares SVM (LS-SVM), relevance vector machines (RVM), Gaussian process regression (GPR), artificial neural network (ANN), and Bayesian ANN (BANN). In this comparison, partial least squares (PLS) regression is used as a linear benchmark, while the relationship of the methods is considered in terms of traditional calibration by ridge regression (RR). The performance of the different methods is demonstrated by their practical applications using three real-life near infrared (NIR) data sets. Different aspects of the various approaches including computational time, model interpretability, potential over-fitting using the non-linear models on linear problems, robustness to small or medium sample sets, and robustness to pre-processing, are discussed. The results suggest that GPR and BANN are powerful and promising methods for handling linear as well as nonlinear systems, even when the data sets are moderately small. The LS-SVM is also attractive due to its good predictive performance for both linear and nonlinear calibrations.