4,574 research outputs found
First ALMA Observation of a Solar Plasmoid Ejection from an X-ray Bright Point
Eruptive phenomena such as plasmoid ejections or jets are an important
feature of solar activity with the potential for improving our understanding of
the dynamics of the solar atmosphere. Such ejections are often thought to be
signatures of the outflows expected in regions of fast magnetic reconnection.
The 304 A EUV line of Helium, formed at around 10^5 K, is found to be a
reliable tracer of such phenomena, but the determination of physical parameters
from such observations is not straightforward. We have observed a plasmoid
ejection from an X-ray bright point simultaneously at millimeter wavelengths
with ALMA, at EUV wavelengths with AIA, in soft X-rays with Hinode/XRT. This
paper reports the physical parameters of the plasmoid obtained by combining the
radio, EUV and X-ray data. As a result, we conclude that the plasmoid can
consist either of (approximately) isothermal 10^5 K plasma that is optically
thin at 100 GHz, or else a 10^4 K core with a hot envelope. The analysis
demonstrates the value of the additional temperature and density constraints
that ALMA provides, and future science observations with ALMA will be able to
match the spatial resolution of space-borne and other high-resolution
telescopes.Comment: 10 page, 5 figures, accepted for publication in Astrophysical Journal
Letter. The movie can be seen at the following link:
http://hinode.nao.ac.jp/user/shimojo/data_area/plasmoid/movie5.mp
Phase Transition in a One-Dimensional Extended Peierls-Hubbard Model with a Pulse of Oscillating Electric Field: II. Linear Behavior in Neutral-to-Ionic Transition
Dynamics of charge density and lattice displacements after the neutral phase
is photoexcited is studied by solving the time-dependent Schr\"odinger equation
for a one-dimensional extended Peierls-Hubbard model with alternating
potentials. In contrast to the ionic-to-neutral transition studied previously,
the neutral-to-ionic transition proceeds in an uncooperative manner as far as
the one-dimensional system is concerned. The final ionicity is a linear
function of the increment of the total energy. After the electric field is
turned off, the electronic state does not significantly change, roughly keeping
the ionicity, even if the transition is not completed, because the ionic
domains never proliferate. As a consequence, an electric field with frequency
just at the linear absorption peak causes the neutral-to-ionic transition the
most efficiently. These findings are consistent with the recent experiments on
the mixed-stack organic charge-transfer complex, TTF-CA. We artificially modify
or remove the electron-lattice coupling to discuss the origin of such
differences between the two transitions.Comment: 17 pages, 9 figure
Photoinduced magnetic bound state in itinerant correlated electron system with spin-state degree of freedom
Photo-excited state in correlated electron system with spin-state degree of
freedom is studied. We start from the two-orbital extended Hubbard model where
energy difference between the two orbitals is introduced. Photo-excited
metastable state is examined based on the effective model Hamiltonian derived
by the two-orbital Hubbard model. Spin-state change is induced by
photo-irradiation in the low-spin band insulator near the phase boundary.
High-spin state is stabilized by creating a ferromagnetic bound state with
photo-doped hole carriers. An optical absorption occurs between the bonding and
antibonding orbitals inside of the bound state. Time-evolution for
photo-excited states is simulated in the time-dependent mean-field scheme.
Pair-annihilations of the photo-doped electron and hole generate the high-spin
state in a low-spin band insulator. We propose that this process is directly
observed by the time-resolved photoemission experiments.Comment: 15 pages, 16 figure
Interrelationships Between Sensation Seeking and Psychopathy
Psychopathic and sensation seeking traits are often correlated; however, sensation seeking alone is not inherently pathological. This study seeks to investigate possible moderating variables between individuals who are high on sensation seeking but low on measures of psychopathic or antisocial traits. Specifically, a positive family environment is hypothesized to be a moderating variable in the development of psychopathic traits among high sensation seekers. A college student sample assessed for psychopathy, sensation seeking, and family functioning is used to test this hypothesis. Significant relationships between all three constructs were found. Similar to previous data, sensation seeking was found to correlate with many elements of psychopathy. Poor family environment was also associated with higher levels of psychopathy. Significant family environmental differences between those high in sensation seeking but low in psychopathy and those high in both sensation seeking and psychopathy were not found. Possible reasons and limitations of this study are explored
Mechanism for Localization of Pheophorbides in Tumor. I. Biodistribution and Subcellular Distribution of 14C-Labeled Pheophorbide and Chlorin in Tumor-Bearing Mice
開始ページ、終了ページ: 冊子体のページ付
Exact solutions of the isoholonomic problem and the optimal control problem in holonomic quantum computation
The isoholonomic problem in a homogeneous bundle is formulated and solved
exactly. The problem takes a form of a boundary value problem of a variational
equation. The solution is applied to the optimal control problem in holonomic
quantum computer. We provide a prescription to construct an optimal controller
for an arbitrary unitary gate and apply it to a -dimensional unitary gate
which operates on an -dimensional Hilbert space with . Our
construction is applied to several important unitary gates such as the Hadamard
gate, the CNOT gate, and the two-qubit discrete Fourier transformation gate.
Controllers for these gates are explicitly constructed.Comment: 19 pages, no figures, LaTeX2
Phase Transition in a One-Dimensional Extended Peierls-Hubbard Model with a Pulse of Oscillating Electric Field: III. Interference Caused by a Double Pulse
In order to study consequences of the differences between the
ionic-to-neutral and neutral-to-ionic transitions in the one-dimensional
extended Peierls-Hubbard model with alternating potentials for the TTF-CA
complex, we introduce a double pulse of oscillating electric field in the
time-dependent Schr\"odinger equation and vary the interval between the two
pulses as well as their strengths. When the dimerized ionic phase is
photoexcited, the interference effect is clearly observed owing to the
coherence of charge density and lattice displacements. Namely, the two pulses
constructively interfere with each other if the interval is a multiple of the
period of the optical lattice vibration, while they destructively interfere if
the interval is a half-odd integer times the period, in the processes toward
the neutral phase. The interference is strong especially when the pulse is
strong and short because the coherence is also strong. Meanwhile, when the
neutral phase is photoexcited, the interference effect is almost invisible or
weakly observed when the pulse is weak. The photoinduced lattice oscillations
are incoherent due to random phases. The strength of the interference caused by
a double pulse is a key quantity to distinguish the two transitions and to
evaluate the coherence of charge density and lattice displacements.Comment: 16 pages, 8 figure
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