Browsing Physics by Date of Publication
Now showing items 61-80 of 2116
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Giant energy product in nanostructured two-phase magnets
(American Physical Society, 1993)Exchange hardening of nanostructured two-phase systems composed of an aligned hard phase and a soft phase with high magnetization is investigated using an approach which yields analytic nucleation fields from the micromagnetic ... -
Steady-State Drainage of an Aqueous Foam
(American Physical Society, 1993)The process of wetting of a monodisperse foam by the continuous addition of liquid from the top has been investigated for a cylindrical column. The velocity of the interface between dry and wet foam was found to vary as ... -
The influence of QSO emission-line velocity shifts on estimates of the intergalactic background intensity
(1993)Observations of the inverse effect indicate that the observed number of QSOs cannot provide sufficient radiation to reionize the intergalactic medium. We reanalyze the data set of one such study and show that bias in the ... -
Permanent magnet variable flux sources.
(IEEE, 1994)Rotatable transversely-magnetized permanent magnet rods can be used to generate variable, uniform magnetic fields or field gradients. A four-rod device for use at the specimen stage of an optical microscope is described ... -
Magnetoresistance in nanostructured Co-Ag prepared by mechanical-alloying
(IEEE, 1994)Fine cobalt and silver powders have been ball-milled to yield a granular solid of composition CoSoAg7a in the form of coarse powder. The material is an intimate mixture of grains of fcc CO in a silver matrix. The cobalt ... -
Non-equilibrium gas-phase nitrogenation
(IEEE, 1994)Non-equilibrium nitrogenation of transition-metal rich rare-earth intermetallics can be used to increase the nitrogen content beyond its equilibrium concentration. For example, nitrogenation of Sm2Fel7 using ammonia ... -
Theory of diffusivelight scattering from disordered materials
(International Society for Optical Engineering, 1994)It is suggested that the measurement of the angular distribution of light transmitted through a thick slab of diffusively scattering material may provide information about the nature of the local scattering events. Monte ... -
The HST absorption line key project. IX. Emission line studies of PG 2251+113
(American Astronomical Society, 1994)We present Hubble Space Telescope (HST) and quasi-simultaneous ground-based observations of the z = 0.3252 QSO PG 2251113. We find a correlation between line widths and the critical density for de-excitation of the forbidden ... -
Engineering the exciton linewidth in II-VI quantum well structures
(SPIE, 1994)The excitonic transition in Il-VI quantum well materials has recently been used as the basis for optical modulators and also as the lasing transition at low temperatures. The central aspect in the use of the exciton ... -
Infrared spectroscopy of high-redshift quasars
(1994)We present H and K spectra (showing redshifted H?, H? and [O III] emission lines) of three radio-loud and three radio-quiet quasars with redshifts z >~ 2, which were obtained using CGS4 on UKIRT The [O III] ?? 4959 + 5007 ... -
The HST quasar absorption line key project. 4: HST faint-object spectrograph and ground-based observations of the unusual low-redshift broad absorption-line quasi-stellar object PG 0043+039
(American Astronomical Society, 1994)Hubble Space Telescope Faint Object Spectrograph (HST FOS) observations have shown that the spectrum of the low-redshift (zem approximately equal to 0.384) QSO PG 0043+039 exhibits weak broad absorption lines (BALs). The ... -
Theory of the exchange coupling in magnetic metallic multilayers
(American Physical Society, 1994)Existing theories of the oscillatory exchange coupling in magnetic metallic multilayers are reconciled within a common approach. It is shown that Ruderman-Kittel-Kasuya-Yosida?type theories and full-confinement quantum-well ... -
Transport properties of Bi2Sr2Can-1CunO2 n+4 thin films
(American Physical Society, 1994)The Hall effect and resistivity have been measured in Bi2Sr2Can-1CunO2n+4 (n=2 and 3) thin films as a function of magnetic field and temperature. In the normal state, the ratio of the normal resistivity to the Hall resistivity ... -
Exchange coupling and energy product in random two-phase aligned magnets.
(IEEE, 1994)Size effects in two-phase Boolean magnets composed of an aligned hard phase and a soft phase with high magnetization are investigated. In 'overcritical' magnets, where the size of the soft regions is larger than the Blochwall ... -
Magnetocrystalline anisotropy of 3d-4f intermetallics: Breakdown of the linear theory.
(American Physical Society, 1994)Applicability of linear theory to magnetic anisotropy of 3d-4f intermetallics is investigated with particular reference to Sm2Fe17N3. A general quantitative criterion for the breakdown of the linear theory is established, ... -
Measurement of Foam Density Profiles Using AC Capacitance
(EDP Sciences, 1995)The dynamics of foam drainage (free, forced and pulsed) is monitored by the determination of local liquid density using a vertical array of capacitors. Liquid profiles are obtained for various drainage experiments. The ... -
Quasi-two-dimensional exciton in ZnSe/ZnMgSSe single quantum well
(American Physical Society, 1995)We have studied the quasi-two-dimensional exciton in ZnSe/ZnxMg1 ? xSySe1 ? y (x=0.85, y=0.21) single quantum wells (SQWs) by photoluminescence and photoluminescence excitation spectroscopy. Self-consistent calculations ... -
Influence of Surface Electric Field on Exciton Photoluminescence of CdS: Self-Reversal of Spectral Lines
(1995)The structure of luminescence spectra of free excitons in CdS single crystals at T = 77 K is investigated. The dip formation is found in the top part of free A and B exciton resonant peaks of photoluminescence (PL) spectra ... -
Epitaxial lift-off of ZnSe based II-VI structures
(1995)The epitaxial lift-off technique is applied to II?VI based structures. Epilayers of 255 nm thickness containing quantum wells are lifted off their substrates and redeposited onto polyimide coated GaAs. The technique has ... -
Simultaneous observation of direct and Raman-scattered O VI lines in the symbiotic nova RR telescopii
(American Astronomical Society, 1995)The optical spectra of some symbiotic binaries show two lines in the red region of the spectrum that cannot be identified with any known allowed or forbidden transitions. A case has been made that these lines are Raman-scattered ...