103,765 research outputs found
Searching for radiative pumping lines of OH masers: II. The 53.3um absorption line towards 1612MHz OH maser sources
This paper analyzes the 53.3um line in the ISO LWS spectra towards a similar
sample of OH/IR sources. We find 137 LWS spectra covering 53.3um and associated
with 47 galactic OH/IR sources. Ten of these galactic OH/IR sources are found
to show and another 5 ones tentatively show the 53.3um absorption while another
7 sources highly probably do not show this line. The source class is found to
be correlated with the type of spectral profile: red supergiants (RSGs) and AGB
stars tend to show strong blue-shifted filling emission in their 53.3um
absorption line profiles while HII regions tend to show a weak red-shifted
filling emission in the line profile. GC sources and megamasers do not show
filling emission feature. It is argued that the filling emission might be the
manifestation of an unresolved half emission half absorption profile of the
53.3um doublet. The 53.3 to 34.6um equivalent width (EW) ratio is close to
unity for RSGs but much larger than unity for GC sources and megamasers while H
II regions only show the 53.3um line. The pump rate defined as maser to IR
photon flux ratio is approximately 5% for RSGs. The pump rates of GC sources
are three order of magnitude smaller. Both the large 53.3 to 34.6um EW ratio
and the small pump rate of the GC OH masers reflect that the two detected
`pumping lines' in these sources are actually of interstellar origin. The pump
rate of Arp 220 is 32%--much larger than that of RSGs, which indicates that the
contribution of other pumping mechanisms to this megamaser is important.Comment: 34 pages, 12 figures, 4 table
Checking the transverse Ward-Takahashi relation at one loop order in 4-dimensions
Some time ago Takahashi derived so called {\it transverse} relations relating
Green's functions of different orders to complement the well-known
Ward-Green-Takahashi identities of gauge theories by considering wedge rather
than inner products. These transverse relations have the potential to determine
the full fermion-boson vertex in terms of the renormalization functions of the
fermion propagator. He & Yu have given an indicative proof at one-loop level in
4-dimensions. However, their construct involves the 4th rank Levi-Civita tensor
defined only unambiguously in 4-dimensions exactly where the loop integrals
diverge. Consequently, here we explicitly check the proposed transverse
Ward-Takahashi relation holds at one loop order in -dimensions, with
.Comment: 20 pages, 3 figures This version corrects and clarifies the previous
result. This version has been submitted for publicatio
Solar transition region in the quiet Sun and active regions
The solar transition region (TR), in which above the photosphere the tempera-
ture increases rapidly and the density drops dramatically, is believed to play
an important role in coronal heating and solar wind acceleration. Long-lasting
up-flows are present in the upper TR and interpreted as signatures of mass
supply to large coronal loops in the quiet Sun. Coronal bright points (BPs) are
local heating phenomena and we found a different Doppler-shift pattern at TR
and coronal temperatures in one BP, which might be related to the twisted loop
system. The dominant energy loss in the lower TR is the Ly-alpha emission. It
has been found that most Ly-alpha radiance profiles are stronger in the blue
peak, an asymmetry opposite to higher order Lyman lines. This asymmetry is
stronger when the downflow in the middle TR is stronger, indicating that the TR
flows play an important role in the line formation process. The peak separation
of Ly-alpha is found to be larger in coronal holes than in the quiet Sun,
reflecting the different magnetic structures and radiation fields between the
two regions. The Lyman line profiles are found to be not reversed in sunspot
plume and umbra regions, while they are obviously reversed in the surrounding
plage region. At TR temperatures, the densities of the sunspot plume and umbra
are a factor of 10 lower than of the plage, indicating that the sunspot plasma
emitting at TR temperatures is higher and possibly more extended above sunspots
than above the plage region.Comment: This paper has been withdrawn by the author because it's not a
referred pape
New Parametrization of Neutrino Mixing Matrix
Global fits to neutrino oscillation data are compatible with tri-bimaximal
mixing pattern, which predicts and . We propose here to
parametrize the tri-bimaximal mixing matrix by its hermitian
generator using the exponential map. Then we use the exponential map
to express the deviations from tri-bimaximal pattern by deriving the hermitian
matrices and . These deviations might come from the symmetry
breaking of the neutrino and charged lepton sectors.Comment: 10 pages, no figures, correted minor typo
Higgsless Models: Lessons from Deconstruction
This talk reviews recent progress in Higgsless models of electroweak symmetry
breaking, and summarizes relevant points of model-building and phenomenology.Comment: 12 pages, 2 figures, Presented at the X Mexican Workshop on Particles
and Field
TandemNet: Distilling Knowledge from Medical Images Using Diagnostic Reports as Optional Semantic References
In this paper, we introduce the semantic knowledge of medical images from
their diagnostic reports to provide an inspirational network training and an
interpretable prediction mechanism with our proposed novel multimodal neural
network, namely TandemNet. Inside TandemNet, a language model is used to
represent report text, which cooperates with the image model in a tandem
scheme. We propose a novel dual-attention model that facilitates high-level
interactions between visual and semantic information and effectively distills
useful features for prediction. In the testing stage, TandemNet can make
accurate image prediction with an optional report text input. It also
interprets its prediction by producing attention on the image and text
informative feature pieces, and further generating diagnostic report
paragraphs. Based on a pathological bladder cancer images and their diagnostic
reports (BCIDR) dataset, sufficient experiments demonstrate that our method
effectively learns and integrates knowledge from multimodalities and obtains
significantly improved performance than comparing baselines.Comment: MICCAI2017 Ora
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