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The structure of hadronic final states in deep inelastic scattering expected from QCD is analyzed in terms of the shape parameters Hl and Cl. We find that the effects of the fragmentation of quarks and gluons into hadrons are typically governed by √s = [Q2(1/x?1)]12. For √s?30 GeV, the distributions of events in H2 and C2 should allow a test of the perturbative QCD prediction of three-jet events.  相似文献   
84.
The effect of electron-electron interactions on the surface states of ionicd-band oxides is reported. The local density of states of surface cations in the valence band region is significantly increased when surface states occur in the band gap. Coulomb repulsion associated with thissurface enhanced covalency tends to force surface states out of the band gap. These results suggest an explanation of recent experiments on SrTiO3 and TiO2.  相似文献   
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A new measurement of the 200Fr -decay half-life, with improved accuracy compared to previous measurements, has been carried out at the Isolde-CERN on-line mass separator. A half-life of 49(4) ms has been obtained, which is substantially different from earlier literature values. For the 196At daughter decay, a half-life of 389(54) ms and an branching ratio b = 94(5)% were measured. In addition, the half-lives of 201, 203, 205Fr and 197,199At are reported.  相似文献   
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A systematic analysis of the growth of rubrene (C42H28), an organic molecule that currently attracts considerable attention with regard to its application in molecular electronics, is carried out by using x-ray absorption spectroscopy and thermal desorption spectroscopy. The results allow us to unravel a fundamental mechanism that effectively limits organic epitaxy for a large class of organic molecules. If the structure of the free molecule differs substantially from that of the corresponding molecular structure in the bulk, the crystallization is severely hampered.  相似文献   
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The cross sections for electron detachment of internally cold Cn- and Aln- clusters were measured using an electrostatic ion beam trap fitted with an internal electron target. The measured electron-impact detachment cross sections for the Cn- (n = 1-9) clusters exhibit even-odd oscillations reflecting the binding energy trend, namely, higher cross sections for weaker binding. Surprisingly, however, these cross sections increase on the average with cluster size, n, in spite of the increase in electron binding. In contrast, the Aln- (n = 2-5) clusters follow the known scaling laws for electron detachment. We suggest that the size-dependent polarizability of these clusters is responsible for the observed behavior.  相似文献   
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Using resonant laser ionization, beta-decay studies, and for the first time mass measurements, three beta-decaying states have been unambiguously identified in 70Cu. A mass excess of -62 976.1(1.6) keV and a half-life of 44.5(2) s for the (6-) ground state have been determined. The level energies of the (3-) isomer at 101.1(3) keV with T(1/2)=33(2) s and the 1+ isomer at 242.4(3) keV with T(1/2)=6.6(2) s are confirmed by high-precision mass measurements. The low-lying levels of 70Cu populated in the decay of 70Ni and in transfer reactions compare well with large-scale shell-model calculations, and the wave functions appear to be dominated by one proton-one neutron configurations outside the closed Z=28 shell and N=40 subshell. This does not apply to the 1+ state at 1980 keV which exhibits a particular feeding and deexcitation pattern not reproduced by the shell-model calculations.  相似文献   
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