3,535 research outputs found
Di-μ-methanolato-κ4 O:O-bis[bis(3-methyl-5-phenyl-1H-pyrazole-κN 2)(nitrato-κO)copper(II)]
Copper nitrate in methanol solution cleaves the N—Cmethanol bond when reacted with 3-methyl-5-phenylpyrazole-1-methanol to yield the centrosymmetric dinuclear title compound, [Cu2(CH3O)2(NO3)2(C10H10N2)4], in which the CuII atom is linked to a nitrate ion, two methanolate ions and two pyrazole ligands in a distorted square-pyramidal environment. The O atom of the nitrate anion occupies the apical site. The crystal structure features intramolecular N—H⋯O hydrogen bonds
Radiation dose and cancer risk from pediatric CT examinations on 64-slice CT: A phantom study
Objective: To measure the radiation dose from CT scans in an anthropomorphic phantom using a 64-slice MDCT, and to estimate the associated cancer risk. Materials and methods: Organ doses were measured with a 5-year-old phantom and thermoluminescent dosimeters. Four protocols; head CT, thorax CT, abdomen CT and pelvis CT were studied. Cancer risks, in the form of lifetime attributable risk (LAR) of cancer incidence, were estimated by linear extrapolation using the organ radiation doses and the LAR data. Results: The effective doses for head, thorax, abdomen and pelvis CT, were 0.7 mSv, 3.5 mSv, 3.0 mSv, 1.3 mSv respectively. The organs with the highest dose were; for head CT, salivary gland (22.33 mGy); for thorax CT, breast (7.89 mGy); for abdomen CT, colon (6.62 mGy); for pelvis CT, bladder (4.28 mGy). The corresponding LARs for boys and girls were 0.015-0.053% and 0.034-0.155% respectively. The organs with highest LARs were; for head CT, thyroid gland (0.003% for boys, 0.015% for girls); for thorax CT, lung for boys (0.014%) and breast for girls (0.069%); for abdomen CT, colon for boys (0.017%) and lung for girls (0.016%); for pelvis CT, bladder for both boys and girls (0.008%). Conclusion: The effective doses from these common pediatric CT examinations ranged from 0.7 mSv to 3.5 mSv and the associated lifetime cancer risks were found to be up to 0.16%, with some organs of higher radiosensitivity including breast, thyroid gland, colon and lungs. © 2010 Elsevier Ireland Ltd. All rights reserved.postprin
Asymmetric spin-wave dispersion due to Dzyaloshinskii-Moriya interaction in an ultrathin Pt/CoFeB film
Employing Brillouin spectroscopy, strong interfacial Dzyaloshinskii-Moriya
interactions have been observed in an ultrathin Pt/CoFeB film. Our
micromagnetic simulations show that spin-wave nonreciprocity due to asymmetric
surface pinning is insignificant for the 0.8nmthick CoFeB film studied. The
observed high asymmetry of the monotonic spin wave dispersion relation is thus
ascribed to strong Dzyaloshinskii-Moriya interactions present at the Pt/CoFeB
interface. Our findings should further enhance the significance of CoFeB as an
important material for magnonic, spintronic and skyrmionic applications.Comment: 12 pages, 4 figure
Real-time Digital Double Framework to Predict Collapsible Terrains for Legged Robots
Inspired by the digital twinning systems, a novel real-time digital double
framework is developed to enhance robot perception of the terrain conditions.
Based on the very same physical model and motion control, this work exploits
the use of such simulated digital double synchronized with a real robot to
capture and extract discrepancy information between the two systems, which
provides high dimensional cues in multiple physical quantities to represent
differences between the modelled and the real world. Soft, non-rigid terrains
cause common failures in legged locomotion, whereby visual perception solely is
insufficient in estimating such physical properties of terrains. We used
digital double to develop the estimation of the collapsibility, which addressed
this issue through physical interactions during dynamic walking. The
discrepancy in sensory measurements between the real robot and its digital
double are used as input of a learning-based algorithm for terrain
collapsibility analysis. Although trained only in simulation, the learned model
can perform collapsibility estimation successfully in both simulation and real
world. Our evaluation of results showed the generalization to different
scenarios and the advantages of the digital double to reliably detect nuances
in ground conditions.Comment: IEEE/RSJ International Conference on Intelligent Robots and Systems
(IROS). Preprint version. Accepted June 202
Radio-to-TeV Phase-resolved Emission from the Crab Pulsar: The Annular Gap Model
In the framework of the three-dimensional (3D) annular gap model with
reasonable parameters (the magnetic inclination angle \alpha = 45 deg and the
view angle \zeta = 63 deg), we first use the latest hight energy data to
self-consistently calculate radio, X-ray, gamma-ray and TeV (MAGIC and VERITAS)
light curves, phase-averaged spectrum and phase-resolved spectra for the Crab
pulsar. It is found that the acceleration electric field and potential in the
annular gap and core gap are huge enough in the several tens of neutron star
radii. The pulsed emission of radio, X-ray, gamma-ray and TeV are mainly
generated from the emission of primary particles or secondary particles with
different emission mechanisms in the nearly similar region of the annular gap
located in the only one magnetic pole, which leads to the nearly
"phase-aligned" multi-wavelength light curves. The emission of peak 1 (P1) and
peak 2 (P2) is originated from the annular gap region near the null charge
surface, while the emission of bridge is mainly originated from the core gap
region. The phase-averaged spectrum and phase-resolved spectra of the Crab
pulsar from soft X-ray to TeV band are produced by four components: synchrotron
radiation from CR-induced and ICS-induced pairs dominates the X-ray band to
soft gamma-ray band (100 eV to 10 MeV); curvature radiation and synchrotron
radiation from the primary particles mainly contribute to gamma-ray band (10
MeV to \sim 20 GeV); ICS from the pairs significantly contributes to the TeV
gamma-ray band (\sim 20 GeV to 400 GeV). The multi-wavelength pulsed emission
from the Crab pulsar has been well modeled with the annular gap and core gap
model. To distinguish our single magnetic pole model from two-pole models, the
convincing values of the magnetic inclination angle and the viewing angle will
play a key role.Comment: 12 pages, 7 figures, 3 tables; published in ApJ on March 12. Due to
the character limitation, the abstract here has been adopted a shortened
versio
Efficient single-molecular white-light emission for iridium-based photoluminescent and electroluminescent white OLEDs
The white organic light-emitting diode has become as a new class of emerging solid-state lighting sources due to its advantage of warm, pure white light emission, flexible lighting, and environmentally friendly indoor lighting. Here, we report three rationally designed cyclometalated [3 + 2+1] iridium(Ⅲ) complexes that emit white emission simultaneously from phosphorescent blue and yellow in the solid-state thin film. The blue GaN-based solid-state white light-emitting diodes with iridium(Ⅲ) complexes as a color converter show a color rendering index of 84.4 and International Commission on Illumination (CIE) coordinates of (0.30, 0.33). In addition, the vacuum-deposited organic light-emitting diode device exhibits a low turn-on voltage of 3.0 V and a maximum luminance (Lmax) of 335 cd m−2 with CIE coordinate of (0.31, 0.33), reaching standard naturally warm white light
Direct observation of the Dzyaloshinskii-Moriya interaction in a Pt/Co/Ni film
The interfacial Dzyaloshinskii-Moriya interaction (DMI) in an in-plane
anisotropic Pt(4nm)/Co(1.6nm)/Ni(1.6nm) film has been directly observed by
Brillouin spectroscopy. It is manifested in the asymmetry of the measured
magnon dispersion relation, from which the DMI constant has been evaluated.
Linewidth measurements reveal that the lifetime of the magnons is asymmetric
with respect to their counter-propagating directions. The lifetime asymmetry is
dependent on the magnon frequency, being more pronounced the higher the
frequency. Analytical calculations of the magnon dispersion relation and
linewidth agree well with experiments.Comment: 15 pages, 4 figure
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