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41.
Summary High-purity indium was analysed by spark source mass spectrometry, using electrical and photoplate detection. For the calibration of the differences in elemental sensitivity, a standard sample was prepared in which 10 impurities were determined by graphite furnace atomic absorption spectrometry. In this way accuracies of less than 40% were obtained for relatively homogeneous elements at ppm and sub-ppm level. About 40 elements could be determined with detection limits of 10 to 30 ppb. Two pattern recognition methods, principal component analysis and clustering analysis, were applied to obtain information on trace element distribution, which indicated that a number of elements were strongly spatially correlated in the analysed sample.
On leave from: Department of Chemistry, Nanjing Normal University, Nanjing, People's Republic of China 相似文献
Chemische Analyse und Verteilungsbestimmung von Spurenelementen in Indium-Matrix durch Funkenquellen-Massenspektrometrie
On leave from: Department of Chemistry, Nanjing Normal University, Nanjing, People's Republic of China 相似文献
42.
T. Yu. Gumerov A. F. Dobrynina R. A. Yusupov V. P. Barabanov 《Russian Journal of Applied Chemistry》2006,79(12):1935-1939
The behavior of real disperse systems with organic impurities was examined under conditions of destabilization by inorganic coagulants. A number of physicochemical methods of analysis and a simulation method were used to identify the character and type of the complexes formed and to calculate their stability constants. 相似文献
43.
The electro-optic response of ferroelectric smectic C* liquid crystals has been studied. Anomalous switching behaviour of such materials which possess a negative dielectric anisotropy has been reported. These materials show a minimum in response time at a sufficiently high field. We present results showing the dependency of this minimum upon spontaneous polarisation and the effect of AC bias. Calculations based upon the equation of motion of the director around the cone are presented which describe this effect and its dependence on the relative magnitudes of the spontaneous polarization and dielectric anisotropy of the material. Good agreement with the experimental results is found. 相似文献
44.
We present a full treatment of the microcanonical ensemble of the ideal hadron-resonance gas starting from a quantum-mechanical formulation which is appropriate for the statistical model of hadronization. By using a suitable transition operator for hadronization we are able to recover the results of the statistical theory, particularly the expressions of the rates of different channels. Explicit formulae are obtained for the phase space volume or density of states of the ideal relativistic gas in quantum statistics as a cluster decomposition, generalizing previous ones in the literature. The problem of the computation of averages in the hadron gas microcanonical ensemble and the comparison with canonical ones will be the main subject of a forthcoming second paper.Received: 8 July 2003, Revised: 17 October 2003, Published online: 5 May 2004 相似文献
45.
In this contribution we shall first introduce the Flux Across Surfaces (FAS) theorem, placing it in the general context of the Quantum Scattering Theory. Then we shall review briefly the theory of resonances in non-relativistic Quantum Mechanics and outline a proof of the FAS theorem for non-relativistic potential scattering, which covers also the case in which there is a zero energy resonance. 相似文献
46.
A generalization of the Bloembergen-Shen model to Raman active molecules with an arbitrary number of normal modes was suggested. The generalized model was used to study Raman echo signal characteristics when a system of molecules was excited by pulses of widths up to one period of optical oscillations. It was shown that a large number of echo responses on Stokes and anti-Stokes components could arise even under a two-pulse action in a continuous monochromatic pumping field. The number of echo responses depended on the number of molecular normal modes and the geometry of measurements. At small exciting pulse “areas,” the echo responses whose Stokes and anti-Stokes components corresponded to normal vibrational modes of a molecule had the highest intensity, whereas the components formed by normal mode combinations were strongly suppressed. 相似文献
47.
M. De Falco F. De Giovanni C. Musella R. Schmidt 《Rendiconti del Circolo Matematico di Palermo》2003,52(1):70-76
A subgroupH of a groupG is said to bepermutable ifHX=XH for every subgroupX ofG. In this paper the structure of groups in which every subgroup either is abelian or permutable is investigated.
This work was done while the last author was visiting the University of Napoli Federico II. He thanks the “Dipartimento di
Matematica e Applicazioni” for its financial support. 相似文献
48.
Pre—Separation Axioms in Fuzzifying Topology 总被引:1,自引:0,他引:1
K.M.AbdEl-Hakeim F.M.Zeyada 《模糊系统与数学》2003,17(1):28-36
1 IntroductionYing[5,6 ] introduced and elementally developed so called fuzzifying topology with the semanticmethod of continuous valued L ogic.Shen[7] introduced and studied T0 -,T1-,T2 (Hausdorff) -,T3(regularity) -,T4 (normality) -separation axioms in fuzzifying topology.In [3 ]the concepts of thefamily of fuzzifying pre-open sets,fuzzifying pre-neighbourhood structure of a point and fuzzifyingpre-closure are introduced and studied.It is worth to mention that pre-separation axioms are … 相似文献
49.
The results of optical study and quantum-chemical simulation of a conjugated organic system, 2-cyclooctylamino-5-nitropyridine (COANP)-fullerene, performed to determine its potential for application as a limiter of visible and near-IR laser radiation and as a material for diffraction elements in systems for reversible recording of optical information, are presented. Complexation between a COANP molecule and fullerene is considered as one of the main mechanisms responsible for the corresponding properties of this system. For the first time, nonlinear optical characteristics of COANP-C60 and COANP-C70 systems are comparatively studied and the intermolecular interaction between a COANP molecule and fullerene is analyzed on the quantum-chemical level. 相似文献
50.
Juan A. Barceló Jonathan Bennett Alberto Ruiz 《Journal of Fourier Analysis and Applications》2003,9(6):541-562
We study the continuity properties of a projection derived from a recent characterization of Herglotz Wave Functions in the plane. Herglotz Wave Functions are the entire solutions of the Helmholtz equation which have L2-Far-Field-Pattern. The behavior of this projection is reminiscent of the Disc Multiplier Operator on both Lp and mixed Lp-normed spaces. In particular a Kakeya type set plays a central role in our analysis. As a consequence we answer a question posed by Alvarez, Folch-Gabayet and Pérez-Esteva. 相似文献