11,998 research outputs found
Electron acceleration by cascading reconnection in the solar corona I Magnetic gradient and curvature effects
Aims: We investigate the electron acceleration in convective electric fields
of cascading magnetic reconnection in a flaring solar corona and show the
resulting hard X-ray (HXR) radiation spectra caused by Bremsstrahlung for the
coronal source. Methods: We perform test particle calculation of electron
motions in the framework of a guiding center approximation. The electromagnetic
fields and their derivatives along electron trajectories are obtained by
linearly interpolating the results of high-resolution adaptive mesh refinement
(AMR) MHD simulations of cascading magnetic reconnection. Hard X-ray (HXR)
spectra are calculated using an optically thin Bremsstrahlung model. Results:
Magnetic gradients and curvatures in cascading reconnection current sheet
accelerate electrons: trapped in magnetic islands, precipitating to the
chromosphere and ejected into the interplanetary space. The final location of
an electron is determined by its initial position, pitch angle and velocity.
These initial conditions also influence electron acceleration efficiency. Most
of electrons have enhanced perpendicular energy. Trapped electrons are
considered to cause the observed bright spots along coronal mass ejection
CME-trailing current sheets as well as the flare loop-top HXR emissions.Comment: submitted to A&
Phase Reversal Diffraction in incoherent light
Phase reversal occurs in the propagation of an electromagnetic wave in a
negatively refracting medium or a phase-conjugate interface. Here we report the
experimental observation of phase reversal diffraction without the above
devices. Our experimental results and theoretical analysis demonstrate that
phase reversal diffraction can be formed through the first-order field
correlation of chaotic light. The experimental realization is similar to phase
reversal behavior in negatively refracting media.Comment: 8 pages, 5 figure
Intravenous meloxicam for the treatment of moderate to severe acute pain: a pooled analysis of safety and opioid-reducing effects.
BACKGROUND AND OBJECTIVES: To describe the safety and tolerability of intravenous meloxicam compared with placebo across all phase II/III clinical trials.
METHODS: Safety data and opioid use from subjects with moderate to severe postoperative pain who received â„1 dose of intravenous meloxicam (5-60 mg) or placebo in 1 of 7 studies (4 phase II; 3 phase III) were pooled. Data from intravenous meloxicam 5 mg, 7.5 mg and 15 mg groups were combined (low-dose subset).
RESULTS: A total of 1426 adults (86.6% white; mean age: 45.8 years) received â„1 dose of meloxicam IV; 517 (77.6% white; mean age: 46.7 years) received placebo. The incidence of treatment-emergent adverse events (TEAEs) in intravenous meloxicam and placebo-treated subjects was 47% and 57%, respectively. The most commonly reported TEAEs across treatment groups (intravenous meloxicam 5-15 mg, 30 mg, 60 mg and placebo, respectively) were nausea (4.3%, 20.8%, 5.8% and 25.3%), headache (1.5%, 5.6%, 1.6% and 10.4%), vomiting (2.8%, 4.6%, 1.6% and 7.4%) and dizziness (0%, 3.5%, 1.1% and 4.8%). TEAE incidence was generally similar in subjects aged \u3e65 years with impaired renal function and the general population. Similar rates of cardiovascular events were reported between treatment groups. One death was reported (placebo group; unrelated to study drug). There were 35 serious adverse events (SAEs); intravenous meloxicam 15 mg (n=5), intravenous meloxicam 30 mg (n=15) and placebo (n=15). The SAEs in meloxicam-treated subjects were determined to be unrelated to study medication. Six subjects withdrew due to TEAEs, including three treated with intravenous meloxicam (rash, localized edema and postprocedural pulmonary embolism). In trials where opioid use was monitored, meloxicam reduced postoperative rescue opioid use.
CONCLUSIONS: Intravenous meloxicam was generally well tolerated in subjects with moderate to severe postoperative pain.
TRIAL REGISTRATION NUMBERS: NCT01436032, NCT00945763, NCT01084161, NCT02540265, NCT02678286, NCT02675907 and NCT02720692
Superconducting Pairing Symmetries in Anisotropic Triangular Quantum Antiferromagnets
Motivated by the recent discovery of a low temperature spin liquid phase in
layered organic compound -(ET)Cu(CN) which becomes a
superconductor under pressure, we examine the phase transition of Mott
insulating and superconducting (SC) states in a Hubbard-Heisenberg model on an
anisotropic triangular lattice. We use a renormalized mean field theory to
study the Gutzwiller projected BCS wavefucntions. The half filled electron
system is a Mott insulator at large on-site repulsion , and is a
superconductor at a moderate . The symmetry of the SC state depends on the
anisotropy, and is gapful with symmetry near the
isotropic limit and is gapless with symmetry at small anisotropy
ratio.Comment: 6 pages, 5 figure
Bulge formation from SSCs in a responding cuspy dark matter halo
We simulate the bulge formation in very late-type dwarf galaxies from
circumnuclear super star clusters (SSCs) moving in a responding cuspy dark
matter halo (DMH). The simulations show that (1) the response of DMH to sinking
of SSCs is detectable only in the region interior to about 200 pc. The mean
logarithmic slope of the responding DM density profile over that area displays
two different phases: the very early descent followed by ascent till
approaching to 1.2 at the age of 2 Gyrs. (2) the detectable feedbacks of the
DMH response on the bulge formation turned out to be very small, in the sense
that the formed bulges and their paired nuclear cusps in the fixed and the
responding DMH are basically the same, both are consistent with
observations. (3) the yielded mass correlation of bulges to their nuclear
(stellar) cusps and the time evolution of cusps' mass are accordance with
recent findings on relevant relations. In combination with the consistent
effective radii of nuclear cusps with observed quantities of nuclear clusters,
we believe that the bulge formation scenario that we proposed could be a very
promising mechanism to form nuclear clusters.Comment: 27 pages, 11 figures, accepted for publication in Ap
Top quark pair production via polarized and unpolarized photons in Supersymmetric QCD
QCD corrections to top quark pair production via fusion of both polarized and
unpolarized photons are calculated in Supersymmetric Model. The corrections are
found to be sizable. The dependence of the corrections on the masses of the
supersymmetric particles is also investigated. Furthermore, we studied CP
asymmetry effects arising from the complex couplings in the MSSM. The CP
violating parameter can reach for favorable parameter values.Comment: 26 pages, LaTex, including 12 figures in 12 eps files. submitted to
Phys. Rev.
Irreducible Highest Weight Representations Of The Simple n-Lie Algebra
A. Dzhumadil'daev classified all irreducible finite dimensional
representations of the simple n-Lie algebra. Using a slightly different
approach, we obtain in this paper a complete classification of all irreducible,
highest weight modules, including the infinite-dimensional ones. As a corollary
we find all primitive ideals of the universal enveloping algebra of this simple
n-Lie algebra.Comment: 24 pages, 24 figures, mistake in proposition 2.1 correcte
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