42,310 research outputs found
Determination of the gaseous hydrogen ductile-brittle transition in copper-nickel alloys
A series of copper-nickel alloys were fabricated, notched tensile specimens machined for each alloy, and the specimens tested in 34.5 MPa hydrogen and in air. A notched tensile ratio was determined for each alloy and the hydrogen environment embrittlement (HEE) determined for the alloys of 47.7 weight percent nickel to 73.5 weight percent nickel. Stacking fault probability and stacking fault energies were determined for each alloy using the x ray diffraction line shift and line profiles technique. Hydrogen environment embrittlement was determined to be influenced by stacking fault energies; however, the correlation is believed to be indirect and only partially responsible for the HEE behavior of these alloys
The possibility of Z(4430) resonance structure description in reaction
The possible description of Z(4430) as a pseudoresonance structure in reaction, is considered. The analysis is performed with
single-scattering contribution to elastic scattering via
intermediate energy.Comment: 3 pages, 4 figure
Periodic Modulation of Extraordinary Optical Transmission through Subwavelength Hole Arrays using Surrounding Bragg Mirrors
The enhanced light transmission through an array of subwavelength holes
surrounded by Bragg mirrors is studied, showing that the mirrors act to confine
the surface plasmons associated with the Extraordinary Optical Transmission
effect, forming a surface resonant cavity. The overall effect is increased
light transmission intensity by more than a factor of three beyond the already
enhanced transmission, independent of whether the Bragg mirrors are on the
input or the output side of the incident light. The geometry of the Bragg
mirror structures controls the enhancement, and can even reduce the
transmission in half. By varying these geometric parameters, we were able to
periodically modulate the transmission of light for specific wavelengths,
consistent with the propagation and interference of surface plasmon waves in a
resonant cavity. FDTD simulations and a wave propagation model verify this
effect.Comment: 9 pages, 5 figure
Interplay between Fermi surface topology and ordering in URuSi revealed through abrupt Hall coefficient changes in strong magnetic fields
Temperature- and field-dependent measurements of the Hall effect of pure and
4 % Rh-doped URuSi reveal low density (0.03 hole/U) high mobility
carriers to be unique to the `hidden order' phase and consistent with an
itinerant density-wave order parameter. The Fermi surface undergoes a series of
abrupt changes as the magnetic field is increased. When combined with existing
de Haas-van Alphen data, the Hall data expose a strong interplay between the
stability of the `hidden order,' the degree of polarization of the Fermi liquid
and the Fermi surface topology.Comment: 4 pages, 4 figures, Accepted to Phys. Rev. Let
Realizations of the -Heisenberg and -Virasoro Algebras
We give field theoretic realizations of both the -Heisenberg and the
-Virasoro algebra. In particular, we obtain the operator product expansions
among the current and the energy momentum tensor obtained using the Sugawara
construction.Comment: 9 page
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