1,263 research outputs found
Temperature dependent Eu 3d-4f X-ray Absorption and Resonant Photoemission Study of the Valence Transition in
We study the mixed valence transition ( 80 K) in
EuNi(SiGe) using Eu 3 X-ray absorption
spectroscopy (XAS) and resonant photoemission spectroscopy (RESPES). The
Eu and Eu main peaks show a giant resonance and the spectral
features match very well with atomic multiplet calculations. The spectra show
dramatic temperature ()-dependent changes over large energies (10 eV)
in RESPES and XAS. The observed non-integral mean valencies of 2.35
0.03 ( = 120 K) and 2.70 0.03 ( = 40 K) indicate homogeneous
mixed valence above and below . The redistribution between
Eu+ and Eu+ states is attributed to
a hybridization change coupled to a Kondo-like volume collapse.Comment: 4 pages, 3 figure
Se-Atom Incorporation in Fullerene and the MD Simulation(II. Radiochemistry)
The formation of Se atom-incorporated fullerenes has been investigated by using radionuclides produced by nuclear reactions. From the trace of radioactivities of ^Se after High Performance Liquid Chromatography (HPLC), it was found that the formation of endohedral fullerenes or heterofullerenes is possible by a recoil process following the nuclear reactions. To confirm the produced materials, ab initio molecular-dynamics simulations based on an all-electron mixed-basis approach were carried out. We found that the insertion of Se atom into C_ cage is much easier than that of As and Ge atoms
Preservation of geochemical characteristics in Permo-Triassic mudstones by metagenesis and low-grade metamorphism in the Tethys Himalaya, Central Nepal
Abstract HKT-ISTP 2013
A
The effect of bolus size on the chewing cycle in humans
No general agreement exists regarding the effect that bolus size has on masticatory movement, probably because both the size and texture of food change during mastication. In this experiment, in order to clarify the effect of bolus size on masticatory movement, a food that does not change in size and texture – chewing gum – was chosen, and the relationship between bolus size and the chewing cycle was analyzed. Ten healthy subjects in their twenties were asked to chew pieces of softened chewing gum of four different sizes. For ten cycles, beginning with the fifth cycle of mastication, gape and masticatory width were calculated for the spatial parameter of the chewing cycle, and cycle time was calculated as the temporal parameter. The relationship between these parameters and the bolus size was investigated. As the bolus size increased, the spatial and temporal parameters increased. In addition, there was a positive correlation between the bolus size and each parameter. The influence of the bolus size was as follows: gape, r = 0.91; masticatory width, r = 0.79; and cycle time, r = 0.74 (all, P < 0.001). From these results it was concluded that the shape of the chewing cycle was altered by the size of the food bolus, and that the changes in sensory input from the peripheries greatly affected the masticatory movement.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42447/1/10890049.pd
Anomalous behaviors of the charge and spin degrees of freedom in the CuO double chains of PrBaCuO
The density-matrix renormalization-group method is used to study the
electronic states of a two-chain Hubbard model for CuO double chains of
PrBaCuO. We show that the model at quarter filling has the charge
ordered phases with stripe-type and in-line--type patterns in the parameter
space, and in-between, there appears a wide region of vanishing charge gap; the
latter phase is characteristic of either Tomonaga-Luttinger liquid or a
metallic state with a spin gap. We argue that the low-energy electronic state
of the CuO double chains of PrBaCuO should be in the metallic state
with a possibly small spin gap.Comment: REVTEX 4, 10 pages, 9 figures; submitted to PR
Using atmospheric observations to evaluate the spatiotemporal variability of CO<sub>2</sub> fluxes simulated by terrestrial biospheric models
Terrestrial biospheric models (TBMs) are used to extrapolate local
observations and process-level understanding of land-atmosphere carbon
exchange to larger regions, and serve as predictive tools for examining
carbon-climate interactions. Understanding the performance of TBMs is thus
crucial to the carbon cycle and climate science communities. In this study,
we present and assess an approach to evaluating the spatiotemporal patterns,
rather than aggregated magnitudes, of net ecosystem exchange (NEE) simulated
by TBMs using atmospheric CO2 measurements. The approach is based on
statistical model selection implemented within a high-resolution atmospheric
inverse model. Using synthetic data experiments, we find that current
atmospheric observations are sensitive to the underlying spatiotemporal flux
variability at sub-biome scales for a large portion of North America, and
that atmospheric observations can therefore be used to evaluate simulated
spatiotemporal flux patterns as well as to differentiate between multiple
competing TBMs. Experiments using real atmospheric observations and four
prototypical TBMs further confirm the applicability of the method, and
demonstrate that the performance of TBMs in simulating the spatiotemporal
patterns of NEE varies substantially across seasons, with best performance
during the growing season and more limited skill during transition seasons.
This result is consistent with previous work showing that the ability of TBMs
to model flux magnitudes is also seasonally-dependent. Overall, the proposed
approach provides a new avenue for evaluating TBM performance based on
sub-biome-scale flux patterns, presenting an opportunity for assessing and
informing model development using atmospheric observations
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