1,688 research outputs found
Generation of more than 300 mW diffraction-limited light at 405 nm by second-harmonic generation of a tapered diode laser with external cavity feedback
Effect of light-load resistance exercise on postprandial amino acid transporter expression in elderly men
Strong Attraction between Charged Spheres due to Metastable Ionized States
We report a mechanism which can lead to long range attractions between
like-charged spherical macroions, stemming from the existence of metastable
ionized states. We show that the ground state of a single highly charged
colloid plus a few excess counterions is overcharged. For the case of two
highly charged macroions in their neutralizing divalent counterion solution we
demonstrate that, in the regime of strong Coulomb coupling, the counterion
clouds are very likely to be unevenly distributed, leading to one overcharged
and one undercharged macroion. This long-living metastable configuration in
turn leads to a long range Coulomb attraction.Comment: REVTEX-published versio
Screening of Spherical Colloids beyond Mean Field -- A Local Density Functional Approach
We study the counterion distribution around a spherical macroion and its
osmotic pressure in the framework of the recently developed
Debye-H"uckel-Hole-Cavity (DHHC) theory. This is a local density functional
approach which incorporates correlations into Poisson-Boltzmann theory by
adding a free energy correction based on the One Component Plasma. We compare
the predictions for ion distribution and osmotic pressure obtained by the full
theory and by its zero temperature limit with Monte Carlo simulations. They
agree excellently for weakly developed correlations and give the correct trend
for stronger ones. In all investigated cases the DHHC theory and its
computationally simpler zero temperature limit yield better results than the
Poisson-Boltzmann theory.Comment: 10 pages, 4 figures, 2 tables, RevTeX4-styl
Critical Dynamics of a Vortex Loop Model for the Superconducting Transition
We calculate analytically the dynamic critical exponent measured in
Monte Carlo simulations for a vortex loop model of the superconducting
transition, and account for the simulation results. In the weak screening
limit, where magnetic fluctuations are neglected, the dynamic exponent is found
to be . In the perfect screening limit, . We relate
to the actual value of observable in experiments and find that , consistent with some experimental results
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