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141.
Strongly temperature dependent peaks in the tunnel conductance of Al-Al oxide-Pd diodes appearing at low temperatures are interpreted in terms of resonant tunneling via impurity states. Such structure was not observed when non-transition metals (Ag, Au, Pb, Sn) were used as counter electrodes. 相似文献
142.
Low frequency signals applied to a grid immersed in a plasma excite ion acoustic waves at the plasma boundaries simulataneous with those excited at the grid. A mechanism is suggested which involves the “direct coupled signal”. 相似文献
143.
J J Christensen D P Wrathall R M Izatt D O Tolman 《The Journal of physical chemistry》1967,71(9):3001-3006
144.
Frank J. Manganiello Larry W. Christensen W.M. Jones 《Journal of organometallic chemistry》1982,235(3):327-334
Contrary to earlier reports [1,2] cyclopropyliron σ complexes can be conveniently prepared in fair to excellent yields by photodecarbonylation of the corresponding acyl complexes. 相似文献
145.
146.
A.N. Christensen O.W. Dietrich W. Kress W.D. Teuchert R. Currat 《Solid State Communications》1979,31(11):795-799
The phonon dispersion curves in δ-NbN have been measured at room temperature in the high symmetry directions Δ, Σ, and ? by coherent inelastic neutron scattering. Anomalies in the dispersion of the acoustic branches have been detected which are quite different from those which have already been reported for superconducting transition metal compounds with 9 valence electrons. In the 10 valence electron compound δ-NbN the soft mode region has moved from the middle of the Σ-direction to the zone boundary. The experimental results are well described by a double shell model which has also been used to calculate the density of states. Using the formalism of Varma and Weber the measured dispersion curves have been reproduced. This shows that the change in the anomalies when going from 9 to 10 valence electrons, is due to a shift in Fermi energy in an essentially rigid band scheme. 相似文献
147.
L. Acker Doris Heiligmann Irmgard Schweitzer A. Kurtenacker O. Reichard J. Koch und H. Christensen 《Fresenius' Journal of Analytical Chemistry》1954,142(3):232-235
Ohne Zusammenfassung 相似文献
148.
N.E. Christensen 《Solid State Communications》1982,44(1):51-54
Self-consistent, Dirac relativistic band-structure calculations have been performed for gold with compressed as well as expanded lattices. Although spin-orbit (SO) parameters usually increase under compression it was found that, in the volume ranges considered here, the SO-splittings in the Au d-band have a positive volume derivative. This is mainly due to the volume-dependent SO-induced hybridization between the EgandT2g states. 相似文献
149.
Rousseau C Ortega-Caballero F Nordstrøm LU Christensen B Petersen TE Bols M 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(17):5094-5101
alpha- and beta-Cyclodextrin 6(A),6(D)-diacids (1 and 2), beta-cyclodextrin-6-monoacid (14), beta-cyclodextrin 6(A),6(D)-di-O-sulfate (16) and beta-cyclodextrin-6-heptasulfate (19) were synthesised. Acids 1, 2 and 14 were made from perbenzylated alpha- or beta-cyclodextrin, by diisobutylaluminum hydride (DIBAL)-promoted debenzylation, oxidation and deprotection. Addition of molecular sieves was found to improve the debenzylation reaction. Sulfates 16 and 19 were made by sulfation of the appropriately partially protected derivatives and deprotection. Catalysis of 4-nitrophenyl glycoside cleavage by these cyclodextrin derivatives was studied. Compounds 1, 2 and 16 were found to catalyse the reaction, with the catalysis following Michaelis-Menten kinetics and depending first order on the phosphate concentration. In a phosphate buffer (0.5 M, 59 degrees C, pH 8.0), K(M) varied from 2-10 mM and the k(cat)/k(uncat) ratio from 80-1000 depending on the stereochemistry of the substrate and the catalyst, with 2 being the best catalyst and with the sulfated 16 also displaying catalytic ability. The monoacid 14 and the heptasulfate 19 were not catalytic. 相似文献
150.
A. Blacha M. Cardona N.E. Christensen S. Ves H. Overhof 《Solid State Communications》1982,43(3):183-187
We have investigated theoretically and experimentally the dependence of the spin-orbit splitting of the edge excitons in CuCl, CuBr, and CuI on volume. The results indicate a large contribution of the change in p(halogen)-d(Cu) hybridization with volume, especially for CuCl. 相似文献