1,487 research outputs found
Alkenylation and Allylation of Aldehydes by Using an Ni/Cr/TDAE Redox System
In 360 females, Bone mineral density (BMD) in lumbar vertebrae (L2-L4) was assessed by quantitative computed tomography (QCT), and the values obtained were compared with the frequency of vertebral transformation or
fracture as assessed by lateral scan image (scanogram) by X-ray CT. A correlation was observed between the frequency of vertebral transformation (or fracture) and lumbar BMD values : BMD under 125 mg/cm(3) was observed over 90% of women with vertebral transformation, and BMD under 70mg/cm(3) was found about 50% of them. These results suggest that decrease in BMD in lumbar vertebrae leads to vertebral transformation or fracture. Thus, measurement of BMD by QCT would be very useful in predicting vertebral
transformation or fractures
Instantons and Monopoles in the Nonperturbative QCD
We study the confinement physics in QCD in the maximally abelian (MA) gauge
using the SU(2) lattice QCD. To clarify the origin of abelian dominance for the
long-range physics, we study the charged-gluon propagator in the lattice QCD,
and find that the effective mass of the charged
gluon is induced by the MA gauge fixing. In the MA gauge, there appears the
global network of the monopole world-line covering the whole system, which
would be identified as monopole condensation at a large scale. To prove
monopole condensation, we apply the dual gauge formalism to the monopole part,
and derive the inter-monopole potential from the dual Wilson loop in the MA
gauge. In the monopole part, which carries the nonperturbative aspects of QCD,
the dual gluon mass is evaluated as 0.5GeV, which is the evidence
of the dual Higgs mechanism by monopole condensation. As for the monopole
structure, the large fluctuation of off-diagonal gluons remains around the
monopole in the MA gauge, and large cancellation occurs between the diagonal
and off-diagonal action densities to keep the total QCD action finite. The
charged-gluon rich region around the QCD-monopole would provide the effective
monopole size as the critical scale of the abelian projected QCD. Instantons
are expected to appear in the charged-gluon rich region around the monopole
world-line in the MA gauge, which leads to the local correlation between
monopoles and instantons.Comment: Invited Lecture presented by H. Suganuma at 1997 Yukawa International
Seminar (YKIS'97) on `` Non-Perturbative QCD -Structure of the QCD Vacuum-'',
2-12 December 1997, in Kyoto, Japan, 12 pages, Plain Late
Properties and Curie Temperature (130 K) of Heavily Mn-doped Quaternary Alloy Ferromagnetic Semiconductor (InGaMn)As Grown on InP
We have studied magnetic properties of heavily Mn-doped
[(In0.44Ga0.56)0.79Mn0.21]As thin films grown by low-temperature molecular-beam
epitaxy (LT-MBE) on InP substrates. The (InGaMn)As with high Mn content (21%)
was obtained by decreasing the growth temperature to 190 degC. When the
thickness of the [(In0.44Ga0.56)0.79Mn0.21]As layer is equal or thinner than 10
nm, the reflection high-energy electron diffraction (RHEED) pattern and
transmission electron microscopy (TEM) show no MnAs clustering, indicating that
a homogeneous single crystal with good quality was grown. In the magnetic
circular dicroism (MCD) measurement, large MCD intensity and high Curie
temperature of 130 K were observed.Comment: 3 pages, 5 figure
Environmental dependence of polycyclic aromatic hydrocarbon emission at z~0.8. Investigation by observing the RX J0152.7-1357 with AKARI
We study the environmental dependence of the strength of polycyclic aromatic
hydrocarbon (PAH) emission by AKARI observations of RX J0152.7-1357, a galaxy
cluster at z=0.84. PAH emission reflects the physical conditions of galaxies
and dominates 8 um luminosity (L8), which can directly be measured with the L15
band of AKARI. L8 to infrared luminosity (LIR) ratio is used as a tracer of the
PAH strength. Both photometric and spectroscopic redshifts are applied to
identify the cluster members. The L15-band-detected galaxies tend to reside in
the outskirt of the cluster and have optically green colour, R-z'~ 1.2. We find
no clear difference of the L8/LIR behaviour of galaxies in field and cluster
environment. The L8/LIR of cluster galaxies decreases with
specific-star-formation rate divided by that of main-sequence galaxies, and
with LIR, consistent with the results for field galaxies. The relation between
L8/LIR and LIR is between those at z=0 and z=2 in the literature. Our data also
shows that starburst galaxies, which have lower L8/LIR than main-sequence, are
located only in the outskirt of the cluster. All these findings extend previous
studies, indicating that environment affects only the fraction of galaxy types
and does not affect the L8/LIR behaviour of star-forming galaxies.Comment: 8 pages, 7 figures. Accepted for Publication in A&
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