33,086 research outputs found
Study of the ionic Peierls-Hubbard model using density matrix renormalization group methods
Density matrix renormalization group methods are used to investigate the
quantum phase diagram of a one-dimensional half-filled ionic Hubbard model with
bond-charge attraction, which can be mapped from the Su-Schrieffer-Heeger-type
electron-phonon coupling at the antiadiabatic limit. A bond order wave
(dimerized) phase which separates the band insulator from the Mott insulator
always exists as long as electron-phonon coupling is present. This is
qualitatively different from that at the adiabatic limit. Our results indicate
that electron-electron interaction, ionic potential and quantum phonon
fluctuations combine in the formation of the bond-order wave phase
Numerical Study on Shear Flow in Sliding Bearing with Partial Slip Surface
AbstractFor revealing the effects of slip on such characteristics as friction force and load-bearing capacity of sliding bearing, shear flows of a Newtonian fluid with a varying partial slip surface were computed using finite volume method. Calculation results showed that slip would decrease the friction force, which however was not affected by the location of slip region. The load-bearing capacity of sliding bearing closely depended on the location of slip region, especially the locations of the starting and end points of slip region. A well-designed partial slip surface can improve the load-bearing capacity, otherwise slip would cause lubrication failure
Teaching evaluation: a complicated issue
To justify/quantify/qualify on teaching evaluation may be difficult and not objective as there are so much variables. Comparing teaching evaluations obtained by individual lecturer may not be meaningful, as each staff facing independent course with different students, course and other variables (or statistically, each is an independent event and a single mean value must not be compared directly with another)
Hawking Radiation of an Arbitrarily Accelerating Kinnersley Black Hole: Spin-Acceleration Coupling Effect
The Hawking radiation of Weyl neutrinos in an arbitrarily accelerating
Kinnersley black hole is investigated by using a method of the generalized
tortoise coordinate transformation. Both the location and temperature of the
event horizon depend on the time and on the angles. They coincide with previous
results, but the thermal radiation spectrum of massless spinor particles
displays a kind of spin-acceleration coupling effect.Comment: 8 pages, no figure, revtex 4.0, revisted version with typesetting
errors and misprint correcte
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