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排序方式: 共有172条查询结果,搜索用时 15 毫秒
41.
F. Adolf K. -P. Sandow R. Hartung S. Jakobs H. Runge A. Kruth O. Schäf U. Guth 《Ionics》1999,5(1-2):109-114
Investigations on lanthanum gallium chromium mixed oxides of the compositions La1.0Ga0.2Cr0.8O3−d and La0.9Ga0.2Cr0.8O3-d are presented regarding their structure, redox stability, conductivity and catalytic activity for the oxidation of propene.
The mixed oxide has perovskite-type structure, high redox stability, an electronic p-type conductivity and low catalytic activity.
If the perovskite-type compound has a deficiency of lanthanum, the electronic conductivity, surface area and catalytic activity
are significantly higher. The catalytic activity is likely comparable to that of gold. Similar to gold electrodes of solid
electrolytes, oxygen electrodes formed with gallium doped lanthanum chromite show a relatively high sensitivity to hydrocarbons
such as propene at temperatures of about 700 °C. The mixed oxide is possibly suitable as electrode material for exhaust gas
sensors using oxide-ion conducting solid electrolytes.
Paper presented at the 5th Euroconference on Solid State Ionics, Benalmádena, Spain, September 13–20, 1998. 相似文献
42.
43.
Ohne Zusammenfassung 相似文献
44.
We report a c.w. intracavity, frequency doubled, rhodamine B dye laser using an RDP crystal 5 cm long. Generated uv powers up to 15 mW are obtained in a single direction with a linewidth of 2 GHz over the range 314–318 nm. A conversion efficiency of about 1.25 × 10-3 W-1 is measured. 相似文献
45.
Ohne ZusammenfassungDiplomarbeit A. Ernst, Halle 1956. 相似文献
46.
H. Brundiers R. Hartung K. Runge O. Schaile C. Weber F. Brun G. Carles M. Cribier J.R. Hubbard G. Laurens L. Moscoso A. Muller S. Zylberajch L. Fluri 《Physics letters. [Part B]》1976,64(1):107-110
A search for exotic mesons has been carried out at the CERN Omega spectrometer. The baryon-exchange reaction π+p → Λ + x++ was studied at 12 GeV/c incident beam momentum. No evidence was found for the existence of doubly-charged strange mesons. The upper limit (95% confidence level) for this reaction is 60 nb for exotic mesons with squared masses from 1 to 7 (GeV/c2)2 and 150 nb for 7 to 13 (GeV/c2)2. These limits are of the same order of magnitude as the exotic cross-sections expected from two-component duality arguments. 相似文献
47.
48.
Intonti F Emiliani V Lienau C Elsaesser T Savona V Runge E Zimmermann R Nötzel R Ploog KH 《Physical review letters》2001,87(7):076801
Spatially resolved photoluminescence spectra of a single quantum well are recorded by near-field spectroscopy. A set of over four hundred spectra displaying sharp emission lines from localized excitons is subject to a statistical analysis of the two-energy autocorrelation function. An accurate comparison with a quantum theory of the exciton center-of-mass motion in a two-dimensional spatially correlated disordered potential reveals clear signatures of quantum mechanical energy level repulsion, giving the spatial and energetic correlations of excitons in disordered quantum systems. 相似文献
49.
A. Runge 《Isotopes in environmental and health studies》2013,49(7):286-287
Zur Isotopenanalyse am Sauerstoff eignen sich entweder elementarer Sauerstoff oder Kohlendiosxid. Kohlenmonxid ist weniger geeignt, da es im Massenspektrum die gleiche Masse wie Stickstoff belegt. 相似文献
50.
Oliver Supplie Oleksandr Romanyuk Christian Koppka Matthias Steidl Andreas Nägelein Agnieszka Paszuk Lars Winterfeld Anja Dobrich Peter Kleinschmidt Erich Runge Thomas Hannappel 《Progress in Crystal Growth and Characterization of Materials》2018,64(4):103-132
The integration of III–V semiconductors with Si has been pursued for more than 25 years since it is strongly desired in various high-efficiency applications ranging from microelectronics to energy conversion. In the last decade, there have been tremendous advances in Si preparation in hydrogen-based metalorganic vapor phase epitaxy (MOVPE) environment, III–V nucleation and subsequent heteroepitaxial layer growth. Simultaneously, MOVPE itself took off in its triumphal course in solid state lighting production demonstrating its power as industrially relevant growth technique. Here, we review the recent progress in MOVPE growth of III–V-on-silicon heterostructures, preparation of the involved interfaces and fabrication of devices structures. We focus on a broad range of in situ, in system and ex situ characterization techniques. We highlight important contributions of density functional theory and kinetic growth simulations to a deeper understanding of growth phenomena and support of the experimental analysis. Besides new device concepts for planar heterostructures and the specific challenges of (001) interfaces, we also cover nano-dimensioned III–V structures, which are preferentially prepared on (111) surfaces and which emerged as veritable candidates for future optoelectronic devices. 相似文献