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1.
Nešetřil and Sopena introduced the concept of oriented game chromatic number. They asked whether the oriented game chromatic
number of partial k-trees was bounded. Here we answer their question positively.
Received: January 12, 2001 Final version received: February 25, 2002 相似文献
2.
T. N. Mamedov V. N. Duginov A. V. Stoykov I. L. Chaplygin D. Herlach U. Zimmermann V. N. Gorelkin J. Major M. Schefzik 《JETP Letters》1998,68(1):64-70
The residual polarization of negative muons in crystal silicon samples with phosphorus (P: 1.6×1013 cm−3) and antimony (Sb: 2×1018 cm−3) impurities is investigated. The measurements are made in a 1000 G magnetic field oriented in a direction transverse to the
muon spin in the temperature range 4–300 K. The relaxation rate and shift of the precession frequency in the silicon sample
with the phosphorus impurity are measured more accurately than previously. It is found that in antimony-doped silicon the
acceptor center
μ
A1 at temperatures below 30 K can be in both ionized and neutral states. The experimental data are interpreted on the basis
of spin-lattice relaxation of the magnetic moment of an acceptor center, formation of acceptor-donor pairs, and recombination
of charge carriers at the acceptor. Preliminary measurements showed a nonzero residual polarization of negative muons in germanium.
Pis’ma Zh. éksp. Teor. Fiz. 68, No. 1, 61–66 (10 July 1998) 相似文献
3.
4.
We compare the efficiency of two Faddeev-type approaches for the nuclear three-body Coulomb problem. The first one is a modification
of Noble’s approach, the second one is due to Sasakawa and Sawada. In an integral-equation formulation both of these methods
rely on the same Green’s operators and driving terms. The differences lie in the treatment of the long-range Coulomb potentials.
Numerical examples show that the modified Faddeev-Noble approach provides for faster convergence. 相似文献
5.
Deák L. Bottyán L. Major M. Nagy D. L. Spiering H. Szilágyi E. Tanczikó F. 《Hyperfine Interactions》2002,144(1-4):45-52
Hyperfine Interactions - Synchrotron Mössbauer Reflectometry (SMR), the grazing incidence nuclear resonant scattering of synchrotron radiation, can be applied to perform depth-selective phase... 相似文献
6.
7.
M. Bokor T. Marek K. Süvegh K. Tompa A. Vértes Zs. Nemes-vetéssy K. Burger 《Journal of Radioanalytical and Nuclear Chemistry》1996,211(1):247-253
The complexes [Zn(1-propyltetraole)6](BF4)2 (Zn-ptz) and [Fe(methyltetrazole)6](BF4)2 (Fe-mtz) were investigated by positron annihilation and solid-state NMR spectroscopy. For Zn-ptz signs of structural rearrangements were found between 70 and 145 K. For the spin-crossover complex Fe-mtz a transition affecting the high-spin stat Fe2+ ions at lattice site B occurs below 15 K. 相似文献
8.
E. Krös L. Ladányi V. Friedrich Zs. Nagy Á. Kis 《Reaction Kinetics and Catalysis Letters》1974,1(4):455-460
The Ru(dipy)
3
2+
-bromate-malonic acid oscillating system was in vestigated. It has been established that at early stages of the reaction the period of oscillation is about 20 sec and the potential change is about 170 mV; chloride at concentrations hiherg than 10–3M is an inhibitor. The rates of both heat evolution and formation of bromomalonic acid are periodic. The activation energy of the oscillating (E) is 16.2 kcal mol–1. Ru(dipy)
3
2+
-- . , 20 , 170 ; , - 10–3 M, . . (E) 16,2 /. 相似文献
9.
Summary Two new analytical techniques are described. The so-called injection technique operates on evaluating a dynamic concentration signal as a result of following the concentration change in a certain part of a flow-through channel after injecting a sample or reagent at a small volume into the current of an appropriate solution flowing at a constant rate.The second technique, the programmed coulometric titration technique, also uses the flow-through channel principle; that means this novel technique allows the more precise titrimetric way of analysis in flowing solutions. In the case of both techniques potentiometric and voltammetric detectors were involved. Several examples proved the multifold advantages of these techniques for environmental analysis.
Neue elektroanalytische Verfahren für die Umweltanalyse
Zusammenfassung Zwei neue Methoden werden beschrieben. Die sog. Injektionstechnik wertet ein dynamisches Konzentrationssignal aus, das sich aus der Änderung in einem Durchflußkanal ergibt, wenn Probe oder Reagens in kleinen Volumina in einen konstant fließenden Flüssigstrom injiziert werden. Das zweite Verfahren, die programmierte coulometrische Titration, erlaubt die Anwendung der genaueren titrimetrischen Technik auf fließende Lösungen. Bei beiden Methoden werden potentiometrische und voltammetrische Detektoren verwendet. Mehrere Beispiele zeigen die vielfachen Vorteile dieser Verfahren bei der Anwendung auf die Analyse von Umweltmaterial.
Presented at the 6th Annual Symposium on Recent Advances in the Analytical Chemistry of Pollutants, April 21–23, 1976; Vienna, Austria 相似文献
10.
Voszka I Szabó Z Csík G Maillard P Gróf P 《Journal of photochemistry and photobiology. B, Biology》2005,79(2):83-88
The effect of the symmetry and polarity of the porphyrin molecules on their membrane localization and interaction with membrane lipids were investigated by electron paramagnetic resonance (EPR). For this purpose, two glycoconjugated tetraphenyl porphyrin derivatives were selected, respectively, symmetrically and asymmetrically substituted. Small unilamellar liposomes composed of dipalmitoylphosphatidylcholine (DPPC) and spin labeled stearic acids were prepared. The spin probe was located at the 5th or 7th or 12th or 16th position of the hydrocarbon chain in order to monitor various regions of the lipid bilayer. EPR spectra of porphyrin-free and porphyrin-bound liposomes were recorded at various temperatures below and above the phase transition temperature of DPPC. The effect on membrane fluidity proved to be stronger with the asymmetrical porphyrin derivative than with the symmetrical one. The rigidity increased when the spin label was near lipid head groups. The difference observed between control and porphyrin-treated samples when measured below the main lipid transition temperature disappeared at higher temperature. When the spin label was near the end of the hydrophobic tails, the symmetrical porphyrin derivative caused increase in fluidity, while the asymmetrical one slightly decreased it. To explain this phenomenon we propose that the asymmetrical derivative exerts a stronger ordering effect caused by its fluorophenyl group located at the level of the lipid heads, which is attenuated to the hydrophobic tails. The perturbing effect of the symmetric derivative could not lead to similar extent of ordering at the head groups and looses the hydrocarbon chains deeper in the membrane. 相似文献