1,161 research outputs found
SLD Fisher information for kinetic uncertainty relations
We investigate a symmetric logarithmic derivative (SLD) Fisher information
for kinetic uncertainty relations (KURs) of open quantum systems described by
the GKSL quantum master equation with and without the detailed balance
condition. In a quantum kinetic uncertainty relation derived by Vu and Saito
[Phys. Rev. Lett. 128, 140602 (2022)], the Fisher information of probability of
quantum trajectory with a time-rescaling parameter plays an essential role.
This Fisher information is upper bounded by the SLD Fisher information. For a
finite time and arbitrary initial state, we derive a concise expression of the
SLD Fisher information, which is a double time integral and can be calculated
by solving coupled first-order differential equations. We also derive a simple
lower bound of the Fisher information of quantum trajectory. We point out that
the SLD Fisher information also appears in the speed limit based on the
Mandelstam-Tamm relation by Hasegawa [arXiv:2203.12421v4]. When the jump
operators connect eigenstates of the system Hamiltonian, we show that the Bures
angle in the interaction picture is upper bounded by the square root of the
dynamical activity at short times, which contrasts with the classical
counterpart.Comment: 12 pages, 3 figure
Temporal and Spatial Analyses of Spectral Indices of Nonthermal Emissions Derived from Hard X-Rays and Microwaves
We studied electron spectral indices of nonthermal emissions seen in hard
X-rays (HXRs) and in microwaves. We analyzed 12 flares observed by the Hard
X-ray Telescope aboard {\it Yohkoh}, Nobeyama Radio Polarimeters (NoRP), and
the Nobeyama Radioheliograph (NoRH), and compared the spectral indices derived
from total fluxes of hard X-rays and microwaves. Except for four events, which
have very soft HXR spectra suffering from the thermal component, these flares
show a gap between the electron spectral indices derived from
hard X-rays and those from microwaves
() of about 1.6. Furthermore, from
the start to the peak times of the HXR bursts, the time profiles of the HXR
spectral index evolve synchronously with those of the microwave
spectral index , keeping the constant gap. We also examined the
spatially resolved distribution of the microwave spectral index by using NoRH
data. The microwave spectral index tends to be larger, which
means a softer spectrum, at HXR footpoint sources with stronger magnetic field
than that at the loop tops. These results suggest that the electron spectra are
bent at around several hundreds of keV, and become harder at the higher energy
range that contributes the microwave gyrosynchrotron emission.Comment: 24 pages, 6 figures, accepted for publication in Ap
Neurologic Complications of Varicella-Zoster Virus Infection
Varicella-zoster virus (VZV) causes a diverse spectrum of neurologic complications: aseptic meningitis, encephalitis, cerebral infarction associated with granulomatous vasculitis, myelitis, and cranial polyneuropathy. These VZV-associated central nervous system (CNS) diseases usually result from reactivation of latent infection in immunosuppressive conditions, such as old age, diabetes mellitus, cancer, human immunodeficiency virus (HIV) infection, and the use of immunosuppressive drugs. However, they also occur in immunocompetent subjects. Since VZV antigen or DNA is often detected in the cerebrospinal fluid of these patients, it is thought that reactivated VZV reaches the central nervous system by direct spread from latently infected sensory ganglia. Analysis of cerebrospinal fluid by PCR is important for the diagnosis of VZV-associated CNS diseases particularly in the absence of exanthema/herpes zoster. Clinicians should be aware of the neurologic complications of VZV infection, because early acyclovir therapy is necessary for these disorders
Enhancement of T-g of Poly(l-lactide) by Incorporation of Biobased Mandelic-Acid-Derived Phenyl Groups by Polymerization and Polymer Blending
A high-molecular-weight polyester of poly(mandelate-co-lactate) (PML) is prepared by ring-opening polymerization of stereo-configuration controlled cyclic diester monomers of methyl-6-phenyl-1,4-dioxane-2,5-dione (MPDD) and lactide. The attained PML shows excellent glassy properties, although the original stereo-configuration of MPDD is not preserved. The intrinsic high glass transition temperature (Tg) of PML is promising, and it is able to be further enhanced by thermal treatment to as high as 90 °C. Interestingly, the enhanced high Tg is attained by only 15 mol% of mandelate content in the polymer chain which is far lower than the ones suggested by theoretical calculation. The enhancement in Tg is also attained by polymer blending of PML and poly(l-lactide) (PLLA). The Tg of the polymer blend also reaches 90 °C which is almost 20 °C higher than the ones suggested by theoretical calculations. These results indicate that the rigid mandelate unit consisting of phenyl groups in PML chain effectively interact with PLLA chains in amorphous domain to restrict their chain mobility. The thermal and glassy properties are sufficient to explore new applications in engineering fields
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