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Hamiltonian formulation of QED in the superaxial gauge
(1982) [Artigo de periódico]We present a hamlltonian formulation of QED in a fully fixed axial gauge. The equal-time commutators for all field variables are computed and are shown to lead to the correct equations of motion. The constraints and gauge ... -
Thermopower and resistivity in amorphous Mg/sub 1-x/Zn/sub x/ alloys
(1982) [Artigo de periódico]Thermopower and resistivity have been measured on a series of Mg1-xZnx amorphous alloys (0.2<X<0.35) over the temperature range 4-300 K. The thermopower data cannot be explained on the basis of the simple Ziman model. Using ... -
Nonlocality of the propagation and the effective nucleos spinorbit interaction
(1982) [Artigo de periódico]The imaginary central and spin-orbit components of the .1.-nucleus optical potential are investigated in a 11'-exchange model. It is found that the effective spin-orbit interaction of the isobar reflects lárge nonlocalities ... -
Collective effects on the operation of free-eletron lasers with an axial guide field
(1982) [Artigo de periódico]The collective interaction in a free-electroii laser with combined helical wiggler and uniform axial guide fields is presented in the linearized regime. The analysis involves a perturbation of the Vlasov-Maxwell equations ... -
Valence and delocalization of yb in the Chevrel-phase YbMo 6 S 8
(1983) [Artigo de periódico]Mãssbauer isomer-shift measurements show that Yb is divalent in YbMo6Sg. The asymmetry of the Yb thermal vibration at 4.2 K obtained from the Goldanskii-Karyagin effect is much smaller than that obtained from a Rietveld ... -
Thermopower and resistivity in amorphous Cu(1-x) Zr(x) alloys
(1983) [Artigo de periódico]The thermopower and resistivity of a series of Cu1-xZrx alloys have been measured between 2 and 300 K for O. 3 < x <O. 7. The composition dependence of the results cannot be explained on the basis of the simple Ziman ... -
The light curve of the ZZ ceti star G226-29
(1983) [Artigo de periódico]G226-29 is a pulsating DA white dwarf, or ZZ Ceti star. Using 65 hr of high-speed photometry accumulated from 1980 to 1982, we have decomposed the light curve of G226-29 into its component pulsations. There are three ... -
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Quadrupole scattering in PrAl/sub 2/
(1983) [Artigo de periódico]We derive the spontaneous anisotropy of the resistivity of the ferromagnetic compound PrAh from magnetoresistance measurements on a single crystal of PrAlz. We ascribe this spontaneous anisotropy of the resistivity to ... -
Magnetoresistance of pd-fe and pd-ni-fe alloys
(1983) [Artigo de periódico]The electrical resistivity ofPd-Fe alloys has been measured in magnetic fields parallel and perpendicular to the current, for a wide range of alloy compositions. The influence of atomic ordering on the magnetoresistance ... -
Green-Function Method for a Mixed-Valence Hamiltonian
(1984) [Artigo de periódico]A Green-function diagrammatic method is utilized to calculate the occupation number of a narrow (j) band in a mixed-valence system. The method is a generalization of the Hubbard-1 approximation for a two-band Hamiltonian. ... -
Kaon-nucleon scattering in an extended cloudy bag model
(1984) [Artigo de periódico]We describe low-energy kaon-nucleon scattering by generalizing the cloudy bag model (CBM) to SU(3) chiral symmetry. We restrict our attention to I = 0, s-wave scattering. We obtain a reasonable fit to both the Zn cross ... -
Pion-nucleon scattering lengths in the cloudy bag model
(1984) [Artigo de periódico]We re-examine pion-nucleon s-wave scattering in the volume coupling version of the CBM. If the effects of multiple scattering are taken into account, one needs some phenomenological repulsive interaction in order to reproduce ... -
Óxidos de ferro em cambissolos brunos no Rio Grande do Sul e sul de Minas Gerais
(1984) [Artigo de periódico]A mineralogia dos óxidos de ferro em horizontes B incipientes em ferropans e crostas de ferro de Cambis-solos Brunos do Rio Grande do Sul e de Minas Gerais, foi analisada por difratometria de raios X. A goethita é o óxido ... -
The 1051 s period of the interacting binary white dwarf amcvn
(1984) [Artigo de periódico]The close binary system AM CVn consists of two white dwarfs; the lower mass white dwarf, a helium white dwarf, is transferring mass to its higher mass companion. The light curve of AM CVn has a double humped variation with ... -
Control software specification and design : an overview
(1984) [Artigo de periódico]Resumo não disponível -
Intermetallic phases formed during tin implantation into iron and steels
(1984) [Artigo de periódico]The surface layers of pure iron, high-carbon steel and stainless steel, ion implanted with 1 X 1017 Sn+ cm-² , have been characterized by means of 119Sn conversion electrons Mossbauer scattering. The intermetallic phases ... -
Rare-earth spin-glasses with uniaxial anisotropy
(1984) [Artigo de periódico]The properties of spin-glasses with uniaxial anisotropy are investigated by magnetization measurements on single crysta1s of Y and Se doped with Er, Dy, Tb, or Gd impurities. In alloys with strong anisotropy, spin-glass ... -
Crossover exponents for the potts model with quadratic symmetry breaking
(1984) [Artigo de periódico]The effect of quadratic symmetry breaking (QSB) on two representations for the Potts vectors in a continuum-field model are studied to two-loop order in renormalized perturbation theory in d=6-E dimensions, in extension ... -
Singularities in the paramagnetism of two-dimensional nearly magnetic itinerant-fermion systems at very low temperature : application to degenerate two-dimensional liquid- 3 He films
(1984) [Artigo de periódico]It is shown that two-dimensional (2D) paramagnon problems exhibit strong algebraic singularities |q2-4K 2/f| -a, when some relevant momentum q is close to twice the Fermi momentum KF. As ali q values from O to 2KF are ...
