25,688 research outputs found
Spontaneous Formation of Stable Capillary Bridges for Firming Compact Colloidal Microstructures in Phase Separating Liquids: A Computational Study
Computer modeling and simulations are performed to investigate capillary
bridges spontaneously formed between closely packed colloidal particles in
phase separating liquids. The simulations reveal a self-stabilization mechanism
that operates through diffusive equilibrium of two-phase liquid morphologies.
Such mechanism renders desired microstructural stability and uniformity to the
capillary bridges that are spontaneously formed during liquid solution phase
separation. This self-stabilization behavior is in contrast to conventional
coarsening processes during phase separation. The volume fraction limit of the
separated liquid phases as well as the adhesion strength and thermodynamic
stability of the capillary bridges are discussed. Capillary bridge formations
in various compact colloid assemblies are considered. The study sheds light on
a promising route to in-situ (in-liquid) firming of fragile colloidal crystals
and other compact colloidal microstructures via capillary bridges
Penguin-Induced Radiative Baryonic B Decays
Weak radiative baryonic B decays B\to\B_1\ov \B_2\gamma mediated by the
electromagnetic penguin process have appreciable rates larger
than their two-body counterparts B\to\B_1\ov \B_2. The branching ratios for
and are sizable,
falling into the range of with the value preferred to
be on the large side, and not far from the bottom baryon radiative decays
and due to the large
short-distance enhancement for penguin transition and the large
strong coupling of the anti-triplet bottom baryons with the B meson and the
light baryon. These penguin-induced radiative baryonic B decay modes should be
accessible by B factories.Comment: 8 pages, 1 figure. Branching ratios are corrected as previous values
are too large by a factor of 2 and a new reference is adde
Generation of isolated attosecond pulses in the far field by spatial filtering with an intense few-cycle mid-infrared laser
We report theoretical calculations of high-order harmonic generation (HHG) of
Xe with the inclusion of multi-electron effects and macroscopic propagation of
the fundamental and harmonic fields in an ionizing medium. By using the
time-frequency analysis we show that the reshaping of the fundamental laser
field is responsible for the continuum structure in the HHG spectra. We further
suggest a method for obtaining an isolated attosecond pulse (IAP) by using a
filter centered on axis to select the harmonics in the far field with different
divergence. We also discuss the carrier-envelope-phase dependence of an IAP and
the possibility to optimize the yield of the IAP. With the intense few-cycle
mid-infrared lasers, this offers a possible method for generating isolated
attosecond pulses.Comment: 8 figure
Comparison of two efficient methods for calculating partition functions
In the long-time pursuit of the solution to calculate the partition function
(or free energy) of condensed matter, Monte-Carlo-based nested sampling should
be the state-of-the-art method, and very recently, we established a direct
integral approach that works at least four orders faster. In present work, the
above two methods were applied to solid argon at temperatures up to K, and
the derived internal energy and pressure were compared with the molecular
dynamics simulation as well as experimental measurements, showing that the
calculation precision of our approach is about 10 times higher than that of the
nested sampling method.Comment: 6 pages, 4 figure
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