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1.
The anisotropic homogeneous 3 is isometrically globally embedded into a nine-dimensional Euclidean or pseudo-Euclidean space. In a special case the Euclidean space is six-dimensional. The space-sections of the anti-Mach metric appear as a submanifold of theE
9. We obtain also the isometric embedding ofSO(3) with its natural Killing metric. 相似文献
2.
Kurt Hiebl Engelbert Tuscher Helmut Bittner 《Monatshefte für Chemie / Chemical Monthly》1979,110(4):869-877
The hydrogen absorption of the phase Ti64Co32–x
Fe
x
(x=0...16) and its influence on the magnetic properties have been investigated. Measurements of the vapour-pressure, wide-line NMR and magnetic susceptibility have been performed. Substitution of Co by Fe does not change the amount of absorbed hydrogen. However the reaction rate of hydriding process, the activation energy of diffusion and the magnetic quantities change upon this substitution. 相似文献
3.
The stannides RE2Au3Sn6 (RE = La, Ce, Pr, Nd, Sm) were synthesized from the elements by arc-melting. Small single crystals were grown by annealing samples in sealed tantalum tubes in an induction furnace with a special annealing sequence. The polycrystalline phases were characterized through their X-ray powder diffraction pattern. The structures of Ce2Au3Sn6, Pr2Au3Sn6, and Nd2Au3Sn6 were refined from single-crystal X-ray diffractometer data. The RE2Au3Sn6 stannides crystallize with the orthorhombic La2Zn3Ge6 type, space group Cmcm. The basic structural building units are Au1@Sn4 tetrahedra and Au2@Sn5 square pyramids. These units are condensed to layers and the structure can be described by a simple stacking of tetrahedral and pyramidal layers with the rare earth cations in between. Temperature dependent susceptibility studies indicate that all rare earth atoms are in the trivalent oxidation state, as their effective magnetic moments match the expected values of the free RE3+ ions. Pr2Au3Sn6 and Nd2Au3Sn6 exhibit antiferromagnetic ordering at TN = 6.3(1) and 6.7(1) K. Investigations of the electrical resistivity of La2Au3Sn6 and Ce2Au3Sn6 confirmed that these compounds are metallic, for La2Au3Sn6 a lower resistivity was observed, in line with the absence of screening unpaired electrons. 119Sn Mössbauer spectra for La2Au3Sn6, Ce2Au3Sn6, Pr2Au3Sn6 and Nd2Au3Sn6 show a complex superposition of three sub-spectra which can be differentiated through their distinctly different quadrupole splitting parameters. The isomer shifts (1.87 to 2.22 mm · s–1) indicate significant s electron density at the tin nuclei. 相似文献
4.
5.
Engelbert Dockner Steffen Jørgensen 《The Journal of the Operational Research Society》1984,35(8):731-739
A monopoly possesses a finite stock of a resource and wishes to determine an optimal pricing policy. The competitive fringe invests in production capacity and wishes to select an optimal investment rate. Demand towards the monopoly depends on price as well as on the sales rate of the competition. Modelling the situation as a differential game, non-cooperative (Nash and Stackelberg) and cooperative (Pareto) equilibria are determined. Owing to the special structure of the game, these solutions can be found in closed form. 相似文献
6.
Engelbert J. Dockner Kazuo Nishimura 《Journal of Difference Equations and Applications》2013,19(6):915-926
We formulate a class of N player difference games and derive open—loop and Markov equilibria. It turns out that both types of equilibria can be characterized by a set of difference equations that describe the equilibrium dynamics. We analyze the stability properties of the difference equations that correspond to an equilibrium and find that in both the open—loop and the Markov game there is convergence towards a steady state equilibrium 相似文献
7.
The indium-rich intermetallic compound SrIrIn6 was synthesized from the elements in a sealed tantalum ampoule at 1173 K, followed by slow cooling for crystal growth. SrIrIn6 crystallizes with a new structure type which was characterized by X-ray powder and single crystal diffraction: Pmma, a = 852.34(2), b = 434.54(5), c = 1059.18(6) pm, wR2 = 0.0178, 884 F2 values, and 32 variables. The SrIrIn6 structure shows two basic building units: (i) Ir@In9 tricapped trigonal prisms (261–292 pm Ir–In) and (ii) distorted bcc In@In8 cubes (301 to 329 pm In–In). The strontium cations fill cages within the complex three-dimensional [IrIn6] network and have coordination number 13 (Sr@In13) in form of a tricapped pentagonal prism. The SrIrIn6 structure can be described as a simple intergrowth variant of SrIrIn4 (LaCoAl4 type) with indium slabs. The crystal chemical similarities with the structures of SrIrIn4, SrIr2In8 and Eu3Ir2In15 are discussed. 相似文献
8.
Jiří Pryček Miroslav Ciganek Zdeněk Šimek 《International journal of environmental analytical chemistry》2013,93(5):313-324
An analytical method based upon the pressurised solvent extraction and gas chromatography and mass spectrometry (GC-MS) for analysis of nitrated derivatives of polycyclic aromatic hydrocarbons (nitro-PAHs) in roadside dust has been developed. Five nitro-PAHs (1-nitronaphthalene, 1-nitropyrene, 9-nitroanthracene, 2-nitrofluorene, 6-nitrochrysene) were chosen for this study because of their variable physical properties and effect on human health. Experiments with spiked inert matrix were used for the best extraction conditions finding. Different extraction conditions (temperature, pressure, solvents and duration of extraction cycle) were examined. The highest recoveries were observed at the extraction pressure of 14?MPa, temperature of 100°C and two cycles of 5?min extraction time, when dichloromethane was used as an extraction solvent. These conditions were applied to the extraction of nitro-PAHs from roadside dust. After extraction the nitro-PAHs fraction was isolated by the silica gel column chromatography. The GC-MS detector was used for analyses of the extracts. Recoveries of nitro-PAHs after extraction from roadside dust ranged from 60% for 9-nitroanthracene to 108% for 6-nitrochrysene. 相似文献
9.
The Dimerization Equilibrium 2 TiCl3,g = Ti2Cl6,g The dimerization of gaseous titanium(III)chloride has been investigated. The measurement have been made in the presence of an excess of TiCl4 by means of a static method using gold as a manometer liquid. The results for the equilibrium 2 TiCl3,g = Ti2Cl6,g are ΔH°(298) = ?40.6 kcal; ΔS°(298) = ?36.4 cl; ΔCp = 4 cal/°, mole. 相似文献
10.
Consider a continuous local martingale X. We say that X satisfies the representation property if any martingale Y of X can be represented as stochastic ITǒ integral of X. Using the method of random time change systematically, in the present paper the representation problem for continuous local martingales is treated. We describe a class of martingales Y that can be represented as stochastic integral of X by probabilistic conditions. This leads to sufficient conditions for the representation property of X being true. Besides, an interesting characterization of continuous processes with independent increments is obtained. In part II. we proceed with general examples, applications to the n-dimensional case, and, in particular, to the n-dimensional time change of continuous local martingales with orthogonal components. 相似文献