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921.
GJ Kramer L Chen RK Fisher WW Heidbrink R Nazikian DC Pace MA Van Zeeland 《Physical review letters》2012,109(3):035003
From numerical simulation and analytical modeling it is shown that fast ions can resonate with plasma waves at fractional values of the particle drift-orbit transit frequency when the plasma wave amplitude is sufficiently large. The fractional resonances, which are caused by a nonlinear interaction between the particle orbit and the wave, give rise to an increased density of resonances in phase space which reduces the threshold for stochastic transport. The effects of the fractional resonances on spatial and energy transport are illustrated for an energetic particle geodesic acoustic mode but they apply equally well to other types of MHD activity. 相似文献
922.
Michael P. Brown John R. Fisher Susan J. Franklin Richard J. Puddephatt Kenneth R. Seddon 《Journal of organometallic chemistry》1978,161(2):C46-C48
It is proposed that the magnitudes of the31P31P and195Pt31P long-range coupling constants in the title complexes may provide a measure of the strength of the PtPt bonding. 相似文献
923.
Galen B. Fisher 《Chemical physics letters》1981,79(3):452-458
Two states of ammonia adsorbed on Pt(111) at 100 K are distinguished by photoemission, work function, and thermal desorption measurements. Ammonia at low coverages (θ ? ), denoted α, orients as an inverted umbrella, bonds by transferring charge via its 3a1 orbital, and increases its dipole moment to 2.0 D. High coverage β-NH3 hydrogen-bonds to α-NH3. 相似文献
924.
925.
Fedor Y NaumkinJohn C Polanyi Duncan Rogers Werner HoferAndrew Fisher 《Surface science》2003,547(3):324-334
Thermal (300 K) and electron-induced reactions of benzene (Bz), chlorobenzene (ClPh), 1,2-dichlorobenzene (1,2-diClPh) and 1,4-dichlorobenzene (1,4-diClPh) with Si(1 0 0)2 × 1 have been examined by scanning tunneling microscopy (STM). Thermal reactions of Bz yielded predominantly the quadruply-σ-bound tight bridge, TB, configuration on top of the Si dimer-rows, For ClPh and 1,2-diClPh, which resembled one another, thermal reaction led with 45-50% yield to the doubly-σ-bound butterfly, BF, configuration, also on top of the dimer-row, and with 20% yield to a novel ‘displaced’, D, configuration to one side of a dimer-row. The adsorbate 1,4-diClPh was alone in favouring a configuration in which neighbouring dimer-rows were ‘linked’ (L) by a bright-feature centrally located between the dimer-rows. By ab initio calculation, we interpret D as due to the rupture of one C-Cl bond per adsorbate molecule, and L to the rupture of two C-Cl’s. The breaking of this weak bond is followed in the former case by attachment of the aromatic ring to one dimer-row, and in the latter to attachment to two adjacent dimer-rows. Application of a −5 V voltage pulse to the STM tip substantially increased the percentage of row-linking structures, L, for 1,4-diClPh, but neither −5 V nor +4-6 V volt pulses resulted in L-type binding of Bz. The postulated L product of 1,4-diClPh, with an aromatic ring linking the two inner Si atoms of adjacent dimer-rows and the two Cl’s on the outer Si atoms of the dimer-rows, is shown to be in accord with ab initio simulation of the observed STM image. 相似文献
926.
N.S. Godwin W.D.M. Rae B. Cooke A. Etchegoyen N.J. Eyre P.S. Fisher G. Proudfoot D. Sinclair 《Nuclear Physics A》1981,351(3):519-531
The reactions 18O11B, 8Li)21Ne, 18O(12C, 9Be)21Ne and 18O(13C, 10B)21F have been studied, using beams of 115 MeV 11B and 12C and 105 MeV 13C incident on a gas target. Shell-model calculations have been performed for 21Ne and 21F, for comparison with the experimental data. It is found that the data can be interpreted using the shell-model spectroscopic factors and a semiclassical reaction theory. Assignments are suggested for several previously unidentified high-spin states in 21Ne and 21F. 相似文献
927.
928.
929.
A P Zens P T Fogle T A Bryson R B Dunlap R R Fisher P D Ellis 《Journal of the American Chemical Society》1976,98(13):3760-3764
930.
Intuitively, one might consider an affinely regular polygon of the Eucidean plane to be the result of applying an affine transformation to a regular polygon. These affinely regular polygons, and their kindred that go by the same name in the Euclidean plane as well as in more general affine planes, have been onjects of investigations at all levels of sophistication and in a remarkable variety of contexts. For example, they arise in linear algebra as a set of vectors that are cyclically permuted by a unimodular matrix. Our purpose is to describe this concept and its attributes in a general setting. The main result is Theorem 1 where we present seven equivalent definitions of affine regularity, one of which appears for the first time. We are careful to distinguish these definitions from the weaker intuitive definition. Our work also features an application of Chebyshev polynomials to describe parameters associated with these polygons. 相似文献