几种元素在高温高密度下离子电高度的类氢平均原子模型计算

根据类氢平均原子模型对Ｆｅ、Ｔｉ、Ｓｉ和Ｍｇ的平均电离度进行了数值计算，结果表明，类氢平均原子模型计算与Ｓａｈａ方程方法以及Ｔｈｏｍａｓ—Ｆｅｒｍｉ模型方法的结果相差不大，利用类氢平均原子模型可对由高压引起的原子轨道畸变进行适当的修正，对修正方法进行了讨论并给出了算例。     

关于二维Navier-Stokes方程非线性Galerkin校正的注记

本文在对二维Navier-Stokes方程及其近似惯性流形领域估计的基础上，讨论了非线性Galerkin方法校正量的一种可能的最优选取。     

Deriving correction functions to model the efficiency of noise barriers with complex shapes using boundary element simulations

The boundary element method (BEM) is a commonly used method to compute the insertion loss of noise barriers having arbitrary cross-sections. For large scale three-dimensional problems, however, the BEM is not feasible. On the other hand, standardized calculation methods for noise mapping are efficient, but shapes other than the straight barrier cannot be properly calculated. Attempts to merge these two approaches by using BEM to derive correction functions based on geometrical quantities such as source and target angle as well as the path length elongation between source and receiver caused by the barrier were usually focused on a small set of barrier types, dimensions, absorptive configurations, source or receiver positions. The main objective of this study is to investigate which functions based on the most common geometrical parameters are well suited for approximating the efficiency of different types of barriers, dimensions and absorptive configurations. To achieve this, numerous combinations of 7 different barrier types, different heights and widths as well as 3 different absorptive configurations were simulated using the 2D BEM for 8 different source positions. The octave-band-wise efficiency, i.e. the frequency-dependent gain in insertion loss compared to an equally high, fully reflective straight barrier was used as a basis for the correction functions. Linear as well as polynomial models were compared yielding a polynomial of third degree in the source and fourth degree in the target angle as the best model. Effects on the error using uniform sampling in the target angle instead of a uniform receiver grid as a basis for the correction functions are also investigated. Furthermore, wide-band efficiencies based on standardized traffic emission spectra are calculated showing small errors compared to single-band errors, in particular in the high-frequency range. A linear interpolation scheme is suggested to deal with barriers having dimensions not simulated in this work.     

Investigation of ICP-MS spectral interferences in the determination of Rh, Pd and Pt in road dust: Assessment of correction algorithms via uncertainty budget analysis and interference alleviation by preliminary acid leaching

A method for classification of the potential spectral interferences in inductively coupled plasma mass spectrometry (ICP-MS) was proposed based on statistical assessment of the interfering signals. The concept was applied to investigate the variety of spectral interferences over the isotopes of Rh, Pd and Pt concerning their analysis in road dust samples. For the significant interferences the applicability of mathematical corrections using two alternative algorithms were studied by uncertainty budget analysis and the approach resulting in lower combined uncertainty of the corrected signals was selected. Further the uncertainty evaluation was used for assessment of the most appropriate Pd isotope to be measured. The adequateness of the mathematical corrections for Rh and Pd was highly relevant to the number of elements causing spectral interferences and the relative analyte/interferent concentrations. This was overcome by preliminary road dust leaching with 0.35 mol l⁻¹ hydrochloric acid. Interferents present as easily soluble salts were substantially removed form the samples while the platinum group metals were not leached which allowed a relative analyte preconcentration to be obtained. For the leached samples the isotopes of Rh and Pd were still spectrally interfered from Sr, Y and Pb but at considerably lesser degree thus after mathematical correction the ICP-MS analysis of Rh, Pd and Pt was reliable and robust using the isotopes 103, 105 and 195, respectively. The method was validated via an alternative analysis based on selective separation of the platinum group metals by microwave-assisted cloud point extraction.     

NDIR多组分气体分析的干扰修正方法研究

介绍了非分散红外(Non-Dispersive Infrared,NDIR)多组分气体分析的一种干扰修正方法.根据逐次积分气体吸收模型和方法,并考虑温度和气压对积分线强和线型的影响,选择洛伦兹展宽线型,得到了CO,CO2,NO和H2O在各个滤波通道的响应系数.利用响应系数建立了用于干扰修正的四元线性回归方程组,通过求解...     

Submicro Determination of Copper and Zinc in Needle Biopsy-Sized Cardiac and Skeletal Muscles by Atomic Absorption Spectroscopy Using Stoichiometric Air-Acetylene Flame

Abstract

A highly sensitive and rapid procedure is described for submicro quantitation of copper and zinc contents from the nitric acid extract of fat free-dry-tissue (FFDT) by a double beam atomic absorption spectrophotometer using stoichiometric air-acetylene flame. Simultaneous background correction was afforded with a deuterium lamp for Zn analysis to eliminate interferences from non-atomic absorption at 213.9 nm. Cu and Zn standards, as well as the muscle extracts, were prepared in an aqueous medium containing 0.75 M Ultrex quality HNO₃ for spectral analysis which did not quench or enhance the relevant absorbance signals. Inherent mineral constituents of muscle such as Ca, Mg, Na, K, and P, when added upto ～10-60 fold greater than the physiological concentration, did not cause either analytical or chemical interferences. Muscle specimens weighing between 0.8-12.0 mg FFDT were extracted in 5 ml of 0.75 M HNO₃ and directly aspirated into the flame. Muscle Cu and Zn contents were expressed in mg/kg FFDT. The smallest sample size confidently analyzed using this technique was ～0.4 mg FFDT which corresponds to 2.0 mg of fresh tissue and can be safely obtained from a patient by muscle needle biopsy. Recovery studies from the inherent muscle matrix revealed 100.01 ± 0.399 and 99.64 ± 0.13% precisions for Cu and Zn respectively.     

Possible corrections to quantum mechanical predictions in a hidden variable model

We derive possible corrections to the statistical predictions of quantum mechanics in measurement over an ensemble of identically prepared systems based on a hidden variable model of quantization developed in the previous work. The corrections are characterized by a dimensionless parameter σ$\sigma$ and the prediction of quantum mechanics is reproduced in the formal limit σ→0$\sigma \to 0$. Quantum mechanics is argued to be reliable for a sufficiently low quantum number.     

求解右定两参数特征值问题的精化Jacobi-Davidson方法(英文)

在文献[1]中,作者M E Hochstenbach和B Plestenjak认为精化的方法不适合两参数特征值问题,原因是求解两参数特征值问题的精化方法存在着三个问题:即精化Ritz向量收敛性差,运算量大,不能计算多个特征值.本文指出,事实并非如此.针对右定两参数特征值问题,本文提出了一种有效的精化数值方法.并通过理论证明和数值实验说明了Ritz值的收敛性,以及精化Ritz向量具有比通常的Ritz向量更好的收敛性.     

插值法在数据修正中的应用

为了使评估的结果达到某种规定的水平,本文研究了运用线性插值、拉格朗日插值以及牛顿插值方法对某公司员工考核数据按照一定的规则进行了修正,同时,对各种方法的修正前、后的结果做了比较．结果表明拉格朗日插值法效果最好,但是计算量偏大;线性插值法虽然效果一般,但是计算复杂度却较低;而牛顿插值法达不到我们预期的效果．     

An LP-based algorithm for the correction of inconsistent linear equation and inequality systems

An algorithm based on linear programming is proposed, which finds for an inconsistent system minimal corrections of the matrix and RHS vector among those providing its consistency