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991.
Summary Gently warming the compound with a dispersion of sodium in a suitable organic solvent reduces nitrogen to ammonia and sulfur, to sulfide.
On the occasion of the hundredth return ofFriedrich Emich's birthday. 相似文献
Zusammenfassung Stickstoff wird zu Ammoniak und Schwefel zu Sulfid reduziert, wenn die organische Verbindung vorsichtig mit einer Dispersion von metallischem Natrium in einem geeigneten organischen Lösungsmittel erwärmt wird.
Résumé En chauffant doucement le composé avec une dispersion de sodium dans un solvant organique convenable, l'azote est réduit en ammoniac et le soufre en sulfure.
On the occasion of the hundredth return ofFriedrich Emich's birthday. 相似文献
992.
993.
M.A.J. Mariscotti H. Beuscher W.F. Davidson Y. Gono H.M. Jäger R.M. Lieder M. Müller-Veggian A. Neskakis D.R. Haenni D.R. Zolnowski 《Nuclear Physics A》1978,311(3):395-412
A level scheme of 144Gd has been established using the 144Sm(α, 4nγ) reaction and in-beam spectroscopy methods. Excitation functions, γ-ray angular distributions, γ-γ coincidence spectra, γ-spectra time related to the cyclotron beam bursts and conversion coefficients for the delayed transitions have been measured.The level scheme comprises 11 levels with spins up to I = 12. Two isomers, a 13 ± 2 ns, 7? state at 2471.4 keV and a 145 ± 30 ns, 10+ state at 3433.0 keV have been observed. The former has similar excitation energy as the 7? isomers in 142Sm, 140Nd and 138Ce and it may arise from the configuration although its lifetime seems to indicate some degree of collectivity. The 10+ state has a similar excitation energy as the 10+ isomer found in 138Ce and it may arise from the dominant configuration. Below the 10+ isomer in 144Gd only two excited states have positive parity; the hitherto known first 2+ and 4+ states. The 11+ and 12+ states must include four-particle configurations or they have to be of collective nature. The latter possibility is supported by the considerable E2/M1 mixture (≈ 20 %) observed for the 11+ to 10+ transition. An analysis of the systematics of ground band levels in the N = 80 isotones shows the same gradual behavior between the two VMI solutions previously found for the Te isotopes. 相似文献
994.
Grard Gouesbet Patrick Gougeon Jean-Noël Le Toulouzan Massamba Thioye Jean-Bernard Guidt 《Particle & Particle Systems Characterization》1988,5(2):51-56
This paper describes new progress obtained with an optical technique called V.I.D.E. (Visible Infra-red Double Extinction) which simultaneously measures mean particle size in the range of 10–120 μm and mean number density in densely laden media (up to 0.1% volume fraction). The underlying theory, taking account of multiple light scattering, is recalled. Simultaneous size and concentration measurements are obtained by simultaneously recording transmittances of the medium at two well chosen wavelengths. Experimental results for suspensions of glass particles in air, are described and discussed. The size of particles given by the technique agrees with that given by optical microscopy and Malvern diffractometry. The V.I.D.E. technique is shown to be very suitable to investigate dense media whose optical thickness is up to nine and for which other techniques fail. 相似文献
996.
997.
Fine precursor powders of particle diameter of 0.50–7 μm and high surface area (9 m2/g) for superionic conducting Na5RESi4O12 (RE=Gd, Y) were successfully produced by spray-drying and an optimised calcination procedure. Using these powders, dense sinters (>98% of theoretical) with ?(NGS) or (the proposed parameter for purity) were obtained under normal sintering conditions. 300°C ionic resistivities were calculated from ac impedance and had values of 5.6 Ω cm with an activation energy for conduction of 4.5 kcal/mol for Na5GdSi4O12 and 7.7 Ω cm and 5.9 kcal/mol for Na5YSi4O12. These values were dependent on the ?(NGS) or ?(NYS). 相似文献
998.
M.V. Lakshmikantham Michael P. Cava Michael Albeck Lars Engman Patrick Carroll Jan Bergman Fred Wudl 《Tetrahedron letters》1981,22(42):4199-4200
The reaction of sodium phenylethynyltellurolate with ethereal hydrogen chloride afforded, in addition to -2,4-dibenzylidene-1,3-di telluretane, a product shown to be the title compound by an X-ray crystallographic analysis. 相似文献
999.
In this study, the disordered network of calcium phosphate glasses is investigated by Raman scattering and 31P magic angle spinning (MAS) solid-state NMR spectroscopies. The use of both spectroscopies in a combined approach allows drawing a detailed understanding of the structure of these glasses. The P―O―P connectivity between successive PO4 tetrahedra is probed using through-bond double quantum-single quantum (DQ-SQ) and triple quantum-single quantum (TQ-SQ) MAS NMR correlation experiments. Over the broad range of glass compositions studied here, two very different phosphate network topologies are encountered. The results obtained for the polyphosphate compositional range (above 50 mol% Ca) allow determining the phosphate chain-length distribution in the glass as a function of the modifier cation content. For the ultraphosphate region (below 50 mol% Ca), the network topology undergoes a sudden change close to 39 mol% Ca which can be interpreted in terms of a rigidity transition. 相似文献
1000.