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1.
ESR spectra of the defect α-Al2O3:Co2+, H+ are reported and used to derive the magnetic tensors g and A. This defect is shown to exist in several types, and models in the framework of the α-Al2O3 structures are proposed. 相似文献
2.
A calculation of the excess internal energy and the osmotic coefficient for a mixture of charged hard spheres of diameters equal to the ionic radii of NaCl, is done in the mean spherical approximation. The results are compared to the best available data, provided by the hypernetted chain theory. The agreement is better for the osmotic coefficient than for the internal energy, and improves at higher concentrations. 相似文献
3.
Non-conjugated -dialkylated alkenes were oxidized to aldehydes in the presence of α,β-unsaturated carbonyl functional groups, providing a new synthesis of and a synthesis of that led to a revised structure for gastrolactone. 相似文献
4.
The synthesis of the title compound is described. Pinacol reduction of 2,2′-dibenzoylbiphenyl followed by dehydration of the trans-diol, so formed, with dimethylformamide dimethyl acetal yielded 55% of the oxirane. Irradiation of the oxide in methylene chloride at 254 nm gave 10,10-diphenyl-9-(10H)phenanthrone as the major photoproduct. 相似文献
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Summary The chlorobenzaldehydes, 2-bromo-4-tolualdehyde and 2-iodobenzaldehyde react with IrCl(CO)(PPh3)2 at 190 to 220° to give PhIrCl2(CO)(PPh3)2,p-tolyl IrBr2(CO)(PPh3)2 and PhIrCl2(CO)(PPh3), respectively. Iodo-and bromobenzene form PhIrCl(Hal)(CO)(PPh3)2 complexes, whereas chlorobenzene does not react under these conditions. Halogen transfer from the aromatic to the metal atom in the reaction of halobenzaldehydes, and halogen extrusion in various homogeneously catalyzed processes, are assumed to follow similar reaction patterns. 相似文献
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Fuchs O Zharnikov M Weinhardt L Blum M Weigand M Zubavichus Y Bär M Maier F Denlinger JD Heske C Grunze M Umbach E 《Physical review letters》2008,100(2):027801
High-resolution x-ray absorption and emission spectra of liquid water exhibit a strong isotope effect. Further, the emission spectra show a splitting of the 1b1 emission line, a weak temperature effect, and a pronounced excitation-energy dependence. They can be described as a superposition of two independent contributions. By comparing with gas phase, ice, and NaOH/NaOD, we propose that the two components are governed by the initial state hydrogen bonding configuration and ultrafast dissociation on the time scale of the O 1s core hole decay. 相似文献
9.
P. Bock G. Heinzelmann B. Pietrzyk G. Blanar W. Blum H. Dietl E. Lorenz R. Richter J. K. Bienlein M. Leissner B. Niczyporuk C. Rippich M. Schmitz H. Vogel F. H. Heimlich P. Lezoch U. Strohbusch 《Zeitschrift fur Physik C Particles and Fields》1980,6(2):125-129
The total cross section fore + e ? annihilation into hadrons for center of mass energies from 9.4 to 9.5 GeV has been measured with the nonmagnetic DESY-Heidelberg detector at DORIS. A value ofR=σhad/σµµ=3.8±0.7 for the continuum region around the Υ (9.46) resonance has been determined. The ratioΓ ee Γ had/Γ tot of electronic, hadronic and total widths has been reevaluated to be (1.00±0.23) keV for the Υ resonance and (0.37±0.16) keV for the Υ′. In addition, a search for directly produced pohotons from Υ decays of the type Υ→γ+gluon+gluon has been performed. The Υ decay into muon pairs has also been searched for. 相似文献
10.