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1.
2.
Letg:U→ℝ (U open in ℝn) be an analytic and K-subanalytic (i. e. definable in ℝ
an
K
, whereK, the field of exponents, is any subfield ofℝ) function. Then the set of points, denoted Σ, whereg does not admit an analytic extension is K-subanalytic andg can be extended analytically to a neighbourhood of Ū\∑.
Partially supported by the European RTN Network RAAG (contract no. HPRN-CT-00271) 相似文献
3.
Two matrix approximation problems are considered: approximation of a rectangular complex matrix by subunitary matrices with
respect to unitarily invariant norms and a minimal rank approximation with respect to the spectral norm. A characterization
of a subunitary approximant of a square matrix with respect to the Schatten norms, given by Maher, is extended to the case
of rectangular matrices and arbitrary unitarily invariant norms. Iterative methods, based on the family of Gander methods
and on Higham’s scaled method for polar decomposition of a matrix, are proposed for computing subunitary and minimal rank
approximants. Properties of Gander methods are investigated in details.
AMS subject classification (2000) 65F30, 15A18 相似文献
4.
V. V. Sidorchuk J. Skubiszewska-Zięba S. V. Khalameida V. A. Zazhigalov R. Leboda 《Russian Journal of Applied Chemistry》2008,81(8):1325-1331
Effect of conditions of hydrothermal and microwave synthesis of supported vanadium-phosphorus oxide catalysts in an aqueous medium on the physicochemical properties of the vanadyl hydrophosphate obtained was studied. The transformations occurring in the system were examined using X-ray phase and differential-thermal analyses, adsorption-structural method, and scanning electron microscopy. 相似文献
5.
Marek Pękała Jan Mucha Benedicte Vertruyen Rudi Cloots Marcel Ausloos 《Journal of magnetism and magnetic materials》2006
Samples of La0.7Ca0.3Mn1−xGaxO3 with x=0, 0.025, 0.05 and 0.10 were prepared by standard solid-state reaction. They were first characterized chemically, including the microstructure. The magnetic properties and various transport properties, i.e. the electrical resistivity, magnetoresistivity (for a field below 8 T), thermoelectric power and thermal conductivity measured each time on the same sample, are reported. The markedly different behaviour of the x=0.1 sample from those with a smaller Ga content, is discussed. The dilution of the Mn3+/Mn4+ interactions with Ga doping considerably reduces the ferromagnetic double exchange interaction within the manganese lattice leading to a decrease of the Curie temperature. The polaron binding energy varies from 224 to 243 meV with increased Ga doping. 相似文献
6.
E. Dębowska 《Zeitschrift für Physik B Condensed Matter》1990,79(3):361-364
Angular Correlation of Annihilation Radiation (ACAR) is shown to be useful to examine the electronic structure of -phase Pd1–y
Ag
y
H
x
system. Hydrogen absorption by Pd1–y
Ag
y
alloys results in the increase of both nearly free andd-localized electron numbers in compliance with the KKR-CPA calculation outcomes. The investigation of -phase systems, PdH
x
hydrides as well as Pd1–y
Ag
y
H
x
materials, failed because of a high concentration of lattice defects. 相似文献
7.
A simple isotherm equation is derived for the adsorption of an organic component onto activated carbon in presence of water vapour. The theoretical results are compared with experimental data for toluene-water vapour-activated carbon, which were published byRipperger andGermerdonk [10].
Symbols a i adsorbate concentration in adsorbent, kg/kg of carbon - a 0i monolayer capacity, kg/kg of carbon - b i kinetic parameter of theLangmuir equation - E j adsorption energy in thej-th layer - i i-th component (1 — water vapour, 2 — organic compound) - j j-th layer - m number of layers - n number of adsorbed components - p partial pressure, Pa - p* saturation partial pressure, Pa - p C water vapour partial pressure at begining of capillary condensation, Pa - surface coverage 相似文献
Vorhersage der Adsorption einer organischen Komponente und Wasserdampf an Aktivkohle
Zusammenfassung Es wird eine einfache Adsorptionsisotherme abgeleitet, welche die gleichzeitige Adsorption eines organischen Stoffes und Wasser an Aktivkohle beschreibt. Die theoretischen Ergebnisse werden mit experimentellen Resultaten vonRipperger undGermerdonk [10] für Toluol-Wasser-Aktivkohle verglichen.
Symbols a i adsorbate concentration in adsorbent, kg/kg of carbon - a 0i monolayer capacity, kg/kg of carbon - b i kinetic parameter of theLangmuir equation - E j adsorption energy in thej-th layer - i i-th component (1 — water vapour, 2 — organic compound) - j j-th layer - m number of layers - n number of adsorbed components - p partial pressure, Pa - p* saturation partial pressure, Pa - p C water vapour partial pressure at begining of capillary condensation, Pa - surface coverage 相似文献
8.
Complex systems of paramagnetic centres existing in demineralised flame coal (71.4 wt% C), medium-rank coal (85.6 wt% C) and
anthracite (94.9 wt% C) were analysed by electron paramagnetic resonance spectroscopy (EPR). Different groups of paramagnetic
centres were searched in macerals (exinite, vitrinite, inertinite) of coals with carbon contents of 73.8 wt% C and 85.6 wt%
C. Experimental EPR spectra were fitted by different superposition of theoretical lines. Total concentration of paramagnetic
centres both in coal and macerals increases with carbon content in the sample. Total concentration of paramagnetic centres
in macerals increases from exinite to inertinite. Four groups of paramagnetic centres were found in medium-rank coal, and
only two groups exist in flame coal and anthracite. The EPR spectrum of medium-rank coal is a superposition of two broad and
two narrow lines. Both broad and narrow, and two narrow lines were measured in EPR spectra of flame coal and anthracite, respectively.
Two types of paramagnetic centres with broad lines and one group with narrow lines exist in exinite and vitrinite from medium-rank
coal. Two narrow components were observed in EPR spectra of its inertinite. Two different broad electron paramagnetic resonance
signals were detected for macerals from low-coalificated coal. Paramagnetic centres systems of medium-rank coal samples reveal
the most complex character. Broad EPR lines were not observed for the higher coalificated samples, i.e., anthracite and inertinite
from medium-rank coal. Narrow lines do not occur in EPR spectra of low-coalificated macerals. Strong dipolar interactions
and fast spin-lattice relaxation processes are characteristic for paramagnetic centres with broad lines. Strong exchange interactions
and short spin-lattice relaxation time were measured for paramagnetic centres with the narrowest EPR signals. 相似文献
9.
Piotr Kowalski Marcin Marszałł Ilona Olędzka Wojciech Czarnowski 《Chromatographia》2007,66(5-6):357-361
Two rapid and popular methods—capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) have been compared
for analysis of cotinine in human urine. Cotinine was analyzed in less than 7 min, with detection limits of 5 and 3.2 ng mL−1 for CE and HPLC, respectively. The performance of the methods was evaluated in terms of sensitivity, specificity, precision,
accuracy, and limits of detection and quantification. Calibration plots were linear in the range 50–4,000 ng mL−1, at least, and mean recoveries were satisfactory for both techniques. The methods were successfully used for quantification
of cotinine in urine. 相似文献
10.
Pyrocarbon/silica gel adsorbents (carbosils, CS) with mesoporous Si-60 (Merck, granule size 0.2–0.5 mm) modified by pyrolysis of CH2Cl2 at 823 K and reaction time from 0.5 to 6 h and then hydrothermally treated at 473 K for 6 h were studied by means of TEM, adsorption and 1H NMR methods. Changes in the structural and adsorptive characteristics of hybrid adsorbents before and after hydrothermal treatment, which depend on pyrocarbon content (C
C), were analyzed on the basis of TEM micrographs and p-nitrophenol and nitrogen adsorption isotherms treated using a constrained regularization method. Interfacial water layers in aqueous suspension of CS were investigated by means of 1H NMR with freezing-out of bulk water at T < 273 K showing nonlinear changes in the Gibbs free energy of interfacial water with increasing C
C because of nonlinear dependence of the structural characteristics of pyrocarbon deposits and CS as a whole on C
C. 相似文献