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51.
Ali Ghaffari 《Proceedings Mathematical Sciences》2007,117(2):177-183
In this paper, among other things, we state and prove the mean ergodic theorem for amenable semigroup algebras. 相似文献
52.
郑洪 《浙江大学学报(理学版)》1996,23(4):342-347
本文介绍了一种钢卷尺刻度在线测量系统 ,它采用了高速摄像及计算机数据处理技术 ,文章阐述了系统的非接触动态测量原理 ,描述了光电信号的处理方法 . 相似文献
53.
Let
l
be the critical exponent associated with the probability thatl independentN-step ordinary random walks, starting at nearby points, are mutually avoiding. Using Monte Carlo methods combined with a maximum-likelihood data analysis, we find that in two dimensions 2=0.6240±0.0005±0.0011 and 3=1.4575±0.0030±0.0052, where the first error bar represents systematic error due to corrections to scaling (subjective 95% confidence limits) and the second error bar represents statistical error (classical 95% confidence limits). These results are in good agreement with the conformal-invariance predictions 2=5/8 and 3=35/24. 相似文献
54.
《Surface and interface analysis : SIA》2004,36(13):1645-1646
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. 相似文献
55.
《Surface and interface analysis : SIA》2005,37(7):589-607
The accuracy of quantitative XPS analysis can be improved using predetermined transmission functions. Two different calibration methods are used for estimating the transmission function T(E) of a photoelectron spectrometer, applying a survey spectra approach (SSA) and a quantified peak‐area approach (QPA) to minimize the quantification error. For the SSA method, Au, Ag and Cu spectra measured with the Metrology Spectrometer II have been used. The new QPA method was built up from Au 4f, Au 4d, Au 4p3/2, Ag 3d, Ag 3p3/2, Cu 3p, Cu 2p3/2, Ge 3p and Ge 2p3/2 standard peak areas, applying adequate ionization cross‐sections and mean free path lengths for different pass energies (10 and 50 eV), lens modes (large area, large area XL, small area 150) and x‐ray sources (Al/Mg Twin and Al Mono). In the energy range 200–1500 eV a transmission function T(E) = a0 + b1E (where a0, b1 and b2 are variable parameters) was found to give an appropriate approximation for eight tested spectrometer settings, implementing the largest changes in the case of pass energy variations. Determination and application of the transmission functions were integrated in the XPS analysis software (UNIFIT 2004) and tested by means of an Ni90Cr10 alloy. The results demonstrate the practicability of the SSA and QPA methods, giving decreased errors of <8% in comparison with errors up to 38% obtained using Wagner's sensitivity factors. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
56.
Summary A new porous polyaromatic ester packing was synthetized for high performance liquid chromatography. The relationship between retention and chain length of the members of homologous series of alkylbenzenes, N-alkylanilines, alkylarylethers, alkylbenzoates and alkylarylketones on this new stationary phase using different eluents was investigated. Using the alkylarylketone scale the retention indices of the homologues and test compounds were calculated. The results were compared with those obtained for poly (styrene-divinylbenzene) polymers. For both types of packing the first members of each homologous series gave non-linear behaviour. The methylene group index increments are different for the studied homologous series; thus there is no simple additivity of the retention indices. The efficiency of the porous polymeric columns is a function of the capacity factor of the solute and the organic component of the eluent. 相似文献
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Per Hyltoft Petersen 《Accreditation and quality assurance》2002,7(11):488-493
The validity of any model depends on its ability to imagine the situation or problem to which it is applied. Further, the
assumptions made in relation to the model are determining for the actual outcome. Within the field of clinical biochemistry
a lot of models for analytical quality specifications, based on a variety of concepts and ’clinical settings’, have been proposed.
A hierarchical structure for application of these approaches and models has been agreed on at several occasions in 1999. In
this hierarchy, the highest rank is given to evaluation of analytical quality specifications based on ’clinical settings’/’clinical
outcome’ models, followed by specifications based on biological variation and on ’clinicians opinions’. This contribution,
deals with the problems of combining random and systematic errors and the implications of application of different models
to a variety of clinical settings.
Received: 1 June, 2002 Accepted: 17 July 2002
Presented at the European Conference on Quality in the Spotlight in Medical Laboratories, 7–9 October 2001, Antwerp, Belgium 相似文献