1,275 research outputs found
On the geometry of Siegel-Jacobi domains
We study the holomorphic unitary representations of the Jacobi group based on
Siegel-Jacobi domains. Explicit polynomial orthonormal bases of the Fock spaces
based on the Siegel-Jacobi disk are obtained. The scalar holomorphic discrete
series of the Jacobi group for the Siegel-Jacobi disk is constructed and
polynomial orthonormal bases of the representation spaces are given.Comment: 15 pages, Latex, AMS fonts, paper presented at the the International
Conference "Differential Geometry and Dynamical Systems", August 25-28, 2010,
University Politehnica of Bucharest, Romani
How to obtain the adhesive strength for double lap joint by using single lap joint
The testing method of adhesive strength of lap joint is prescribed in Japanese Industrial Standard (JIS K6850). However, it has been reported that the strength of double lap joint (DLJ) is about two times larger than the one of single lap joint (SLJ). Therefore, suitable testing method has been required from industries. In this study, the equivalent conditions of strength for SLJ and DLJ are investigated in terms of the intensity of singular stress field (ISSF) appearing at the interface end. First, in order to minimize the bend effect for SLJ, the effect of the specimen geometry on ISSF and deformation angle at the interface corner is considered under the same adhesive geometry and load P. It is found that the minimum ISSF of SLJ can be obtained when the adherend thickness t1 is large enough, and the deformation angle at interface corner is also smallest when adherend thickness t1 is large enough. Therefore, it is necessary to use the specimen with thicker adherend thickness. Then, the equivalent conditions of strength for SLJ and DLJ is investigated by changing adherend thickness. The results show that the strength of the DLJ in JIS (t1=1.5mm) can be obtained by using the SLJ with adherend thickness t1=7mm. When the adherend thickness t1≥25mm, the strength of SLJ is nearly equal to that of DLJ.6th International Conference on Fracture Fatigue and Wear, 26–27 July 2017, Porto, Portuga
The HI and Ionized Gas Disk of the Seyfert Galaxy NGC 1144 = Arp 118: A Violently Interacting Galaxy with Peculiar Kinematics
We present observations of the distribution and kinematics of neutral and
ionized gas in NGC 1144, a galaxy that forms part of the Arp 118 system.
Ionized gas is present over a huge spread in velocity (1100 km/s) in the disk
of NGC 1144, but HI emission is detected over only 1/3 of this velocity range,
in an area that corresponds to the NW half of the disk. In the nuclear region
of NGC 1144, a jump in velocity in the ionized gas component of 600 km/s is
observed. Faint, narrow HI absorption lines are also detected against radio
sources in the SE part of the disk of NGC 1144, which includes regions of
massive star formation and a Seyfert nucleus. The peculiar HI distribution,
which is concentrated in the NW disk, seems to be the inverse of the molecular
distribution which is concentrated in the SE disk. Although this may partly be
the result of the destruction of HI clouds in the SE disk, there is
circumstantial evidence that the entire HI emission spectrum of NGC 1144 is
affected by a deep nuclear absorption line covering a range of 600 km/s, and is
likely blueshifted with respect to the nucleus. In this picture, a high
column-density HI stream is associated with the nuclear ionized gas velocity
discontinuity, and the absorption effectively masks any HI emission that would
be present in the SE disk of NGC 1144.Comment: manuscript, arp118.ps: 28 pages; 1 Table: arp118.tab1.ps; 16 Figures:
arp118.fig1-16.ps; Accepted to Ap
IC 225: a dwarf elliptical galaxy with a peculiar blue core
We present the discovery of a peculiar blue core in the elliptical galaxy IC
225 by using images and spectrum from the Sloan Digital Sky Survey (SDSS). The
outer parts of the surface brightness profiles of u-, g-, r-, i- and z-band
SDSS images for IC 225 are well fitted with an exponential function. The
fitting results show that IC 225 follows the same relations between the
magnitude, scale length and central surface brightness for dwarf elliptical
galaxies. Its absolute blue magnitude (M_B) is -17.14 mag, all of which suggest
that IC 225 is a typical dwarf elliptical galaxy. The g-r color profile
indicates a very blue core with a radius of 2 arcseconds, which is also clearly
seen in the RGB image made of g-, r- and i-band SDSS images. The SDSS optical
spectrum exhibits strong and very narrow nebular emission lines. The metal
abundances derived by the standard methods, which are 12+log(O/H) = 8.98,
log(N/O) = -0.77 and 12+log(S+/H+) = 6.76, turn out to be significantly higher
than that predicted by the well-known luminosity-metallicity relation. After
carefully inspecting the central region of IC 225, we find that there are two
distinct nuclei, separated by 1.4 arcseconds, the off-nucleated one is even
bluer than the nucleus of IC 225. The asymmetric line profiles of higher-order
Balmer lines indicate that the emission lines are bluer shifted relative to the
absorption lines, suggesting that the line emission arises from the off-center
core, whose nature is a metal-rich Hii region. To the best of our knowledge, it
is the first high-metallicity Hii region detected in a dwarf elliptical galaxy.Comment: 7 figures, accepted for publication in A
Processing graded feedback: Electrophysiological correlates of learning from small and large errors
Feedback processing is important for learning and therefore may affect the consolidation of skills. Considerable research demonstrates electrophysiological differences between correct and incorrect feedback, but how we learn from small versus large errors is usually overlooked. This study investigated electrophysiological differences when processing small or large error feedback during a time estimation task. Data from high-learners and low-learners were analyzed separately. In both high- and low-learners, large error feedback was associated with higher feedback-related negativity (FRN) and small error feedback was associated with a larger P300 and increased amplitude over the motor related areas of the left hemisphere. In addition, small error feedback induced larger desynchronization in the alpha and beta bands with distinctly different topographies between the two learning groups: The high-learners showed a more localized decrease in beta power over the left frontocentral areas, and the low-learners showed a widespread reduction in the alpha power following small error feedback. Furthermore, only the high-learners showed an increase in phase synchronization between the midfrontal and left central areas. Importantly, this synchronization was correlated to how well the participants consolidated the estimation of the time interval. Thus, although large errors were associated with higher FRN, small errors were associated with larger oscillatory responses, which was more evident in the high-learners. Altogether, our results suggest an important role of the motor areas in the processing of error feedback for skill consolidation
Farnesyl diphosphate synthase may determine the accumulation level of (−)-rotundone in 'Syrah' grapes
(−)-Rotundone is an oxygenated sesquiterpene responsible for the peppery aroma in grapes, wines, herbs, and spices, and it was first identified in 'Syrah' wine from Australia. In this study, we demonstrated the expression profiles of genes related to (−)-rotundone biosynthesis during the maturation of 'Syrah' grapes from two different vineyards, namely, the Iwaimura and Johnohira vineyards in Japan. The α-guaiene and (−)-rotundone accumulation levels in the grape exocarp from the Johnohira vineyard, which has a cool climatic condition located at a high altitude, were extremely higher than those from the Iwaimura vineyard. Among the 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway genes, the transcript levels of 1-deoxy-D-xylulose-5-phosphate synthase gene (DXS) in the grape exocarp from the Johnohira vineyard were higher than those from the Iwaimura vineyard after véraison. The expression levels of the mevalonate pathway genes, Vitis vinifera terpene synthase gene (VvTPS24) and cytochrome P450 gene (CYP71BE5) in the final step of (−)-rotundone biosynthesis were not significantly different between samples from the two vineyards during grape maturation. In contrast, the farnesyl diphosphate synthase gene (FPPS) expression level was considerably higher in the grape exocarp from the Johnohira vineyard than in that from the Iwaimura vineyard. Consistent with these observations, FPPS was constantly expressed at higher level in 'Syrah' grape exocarp compared with 'Merlot' grape which is a low-rotundone cultivar. These findings suggest that FPPS may play a key role in determining the accumulation level of (−)-rotundone, which can provide abundant substrates for VvTPS24 catalysis to produce α-guaiene as a precursor of (−)-rotundone. In addition, among the MEP pathway genes, DXS may have a regulatory role for a precursor supply from the plastids to (−)-rotundone biosynthesis
The Relative Orientation of Nuclear Accretion and Galaxy Stellar Disks in Seyfert Galaxies
We use the difference (delta) between the position angles of the nuclear
radio emission and the host galaxy major axis to investigate the distribution
of the angle (beta) between the axes of the nuclear accretion disk and the host
galaxy disk in Seyfert galaxies. We provide a critical appraisal of the quality
of all measurements, and find that the data are limited by observational
uncertainties and biases, such as the well known deficiency of Seyfert galaxies
of high inclination. There is weak evidence that the distribution of delta for
Seyfert 2 galaxies may be different (at the 90% confidence level) from a
uniform distribution, while the Seyfert 1 delta distribution is not
significantly different from a uniform distribution or from the Seyfert 2 delta
distribution. The cause of the possible non-uniformity in the distribution of
delta for Seyfert 2 galaxies is discussed. Seyfert nuclei in late-type spiral
galaxies may favor large values of delta (at the ~96% confidence level), while
those in early-type galaxies show a more or less random distribution of delta.
This may imply that the nuclear accretion disk in non-interacting late-type
spirals tends to align with the stellar disk, while that in early-type galaxies
is more randomly oriented, perhaps as a result of accretion following a galaxy
merger.
We point out that biases in the distribution of inclination translate to
biased estimates of beta in the context of the unified scheme. When this effect
is taken into account, the distributions of beta for all Seyferts together, and
of Seyfert 1's and 2's separately, agree with the hypothesis that the radio
jets are randomly oriented with respect to the galaxy disk. The data are
consistent with the expectations of the unified scheme, but do not demand it.Comment: To appear in the Astrophysical Journal, Vol 516 #1, May 1, 1999.
Corrected figure placement within pape
Hepatic Glucose Metabolism of Diabetic Patient Evaluated by 18FDG PET Scan
開始ページ、終了ページ: 冊子体のページ付
- …