385 research outputs found
Energy release mechanism of current loops in the solar atmosphere: solar flares and corona heating
Mechanical modulation of single-electron tunneling through molecular-assembled metallic nanoparticles
We present a microscopic study of single-electron tunneling in nanomechanical
double-barrier tunneling junctions formed using a vibrating scanning nanoprobe
and a metallic nanoparticle connected to a metallic substrate through a
molecular bridge. We analyze the motion of single electrons on and off the
nanoparticle through the tunneling current, the displacement current and the
charging-induced electrostatic force on the vibrating nanoprobe. We demonstrate
the mechanical single-electron turnstile effect by applying the theory to a
gold nanoparticle connected to the gold substrate through alkane dithiol
molecular bridge and probed by a vibrating platinum tip.Comment: Accepted by Phys. Rev.
Birman-Wenzl-Murakami Algebra and the Topological Basis
In this paper, we use entangled states to construct 9x9-matrix
representations of Temperley-Lieb algebra (TLA), then a family of 9x9-matrix
representations of Birman-Wenzl-Murakami algebra (BWMA) have been presented.
Based on which, three topological basis states have been found. And we apply
topological basis states to recast nine-dimensional BWMA into its
three-dimensional counterpart. Finally, we find the topological basis states
are spin singlet states in special case.Comment: 11pages, 1 figur
How Many CMEs Have Flux Ropes? Deciphering the Signatures of Shocks, Flux Ropes, and Prominences in Coronagraph Observations of CMEs
We intend to provide a comprehensive answer to the question on whether all
Coronal Mass Ejections (CMEs) have flux rope structure. To achieve this, we
present a synthesis of the LASCO CME observations over the last sixteen years,
assisted by 3D MHD simulations of the breakout model, EUV and coronagraphic
observations from STEREO and SDO, and statistics from a revised LASCO CME
database. We argue that the bright loop often seen as the CME leading edge is
the result of pileup at the boundary of the erupting flux rope irrespective of
whether a cavity or, more generally, a 3-part CME can be identified. Based on
our previous work on white light shock detection and supported by the MHD
simulations, we identify a new type of morphology, the `two-front' morphology.
It consists of a faint front followed by diffuse emission and the bright
loop-like CME leading edge. We show that the faint front is caused by density
compression at a wave (or possibly shock) front driven by the CME. We also
present high-detailed multi-wavelength EUV observations that clarify the
relative positioning of the prominence at the bottom of a coronal cavity with
clear flux rope structure. Finally, we visually check the full LASCO CME
database for flux rope structures. In the process, we classify the events into
two clear flux rope classes (`3-part', `Loop'), jets and outflows (no clear
structure). We find that at least 40% of the observed CMEs have clear flux rope
structures. We propose a new definition for flux rope CMEs (FR-CMEs) as a
coherent magnetic, twist-carrying coronal structure with angular width of at
least 40 deg and able to reach beyond 10 Rsun which erupts on a time scale of a
few minutes to several hours. We conclude that flux ropes are a common
occurrence in CMEs and pose a challenge for future studies to identify CMEs
that are clearly not FR-CMEs.Comment: 26 pages, 9 figs, to be published in Solar Physics Topical Issue
"Flux Rope Structure of CMEs
Direct Measurements of the Branching Fractions for and and Determinations of the Form Factors and
The absolute branching fractions for the decays and
are determined using singly
tagged sample from the data collected around 3.773 GeV with the
BES-II detector at the BEPC. In the system recoiling against the singly tagged
meson, events for and events for decays are observed. Those yield
the absolute branching fractions to be and . The
vector form factors are determined to be
and . The ratio of the two form
factors is measured to be .Comment: 6 pages, 5 figure
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