172 research outputs found
Phase structure of NJL model with weak renormalization group
We analyze the chiral phase structure of the Nambu--Jona-Lasinio model at
finite temperature and density by using the functional renormalization group
(FRG). The renormalization group (RG) equation for the fermionic effective
potential is given as a partial differential equation, where
and is a dimensionless RG scale. When the dynamical
chiral symmetry breaking (DSB) occurs at a certain scale ,
has singularities originated from the phase transitions, and then
one cannot follow RG flows after . In this study, we introduce the weak
solution method to the RG equation in order to follow the RG flows after the
DSB and to evaluate the dynamical mass and the chiral condensate in low
energy scales. It is shown that the weak solution of the RG equation correctly
captures vacuum structures and critical phenomena within the pure fermionic
system. We show the chiral phase diagram on temperature, chemical potential and
the four-Fermi coupling constant.Comment: 32 pages, 12 figures; Version published in Nuclear Physics
Explosive Nucleosynthesis in Magnetohydrodynamical Jets from Collapsars II. Heavy-Element Nucleosynthesis of s, r, p-Processes
We investigate the nucleosynthesis in a massive star of 70 M_solar with solar
metallicity in the main sequence stage. The helium core mass after hydrogen
burning corresponds to 32 M_solar. Nucleosynthesis calculations have been
performed during the stellar evolution and the jetlike supernova explosion of a
collapsar model, where the weak s-, p-, and r-processes are taken into account.
We confirm that s-elements of 60 < A < 90 are highly overproduced relative to
the solar abundances in the hydrostatic nucleosynthesis. During oxygen burning,
p-elements of A > 90 are produced via photodisintegrations of seed s-elements.
However, the produced p-elements are disintegrated in later stages except for
^{180}Ta. In the explosive nucleosynthesis, elements of 90 < A < 160 are
significantly overproduced relative to the solar values owing to the r-process.
Only heavy p-elements (N > 50) are overproduced via the p-process. Compared
with the previous study of r-process nucleosynthesis calculations in the
collapsar model of 40 M_solar by Fujimoto et al. 2007, 2008, our jet model
cannot contribute to the third peak of the solar r-elements and intermediate
p-elements. Averaging the overproduction factors over the progenitor masses
with the use of Salpeter's IMF, we suggest that the 70 M_solar star could
contribute to the solar weak s-elements of 60 < A < 90 and neutron-rich
elements of 90 < A < 160. We confirm the primary synthesis of light p-elements
in the ejected matter of high peak temperature. The ejected matter has [Sr/Eu]
\sim -0.4, which is different from that of a typical r-process-enriched star
CS22892-052 ([Sr/Eu] \sim -1). We find that Sr-Y-Zr isotopes are primarily
synthesized in the explosive nucleosynthesis in a similar process of the
primary production of light p-elements, which has been considered as one of the
sites of a lighter element primary process (LEPP).Comment: 25 pages, 13 figures, 2 tables, accepted for publication in Progress
of Theoretical Physic
The Ds(2317) and Ds(2463) Mesons as Scalar and Axial-Vector Chiralons in the Covariant Level-Classification Scheme
The new narrow mesons observed recently in the final states Ds+ pi0 and Ds*+
pi0 are pointed out to be naturally assigned as the ground-state scalar and
axial-vector chiralons in the c sbar system, which would newly appear in the
covariant hadron-classification scheme proposed a few years ago.Comment: 8 pages, 1 figure, uses ptptex.st
Extracting Important Tweets for News Writers using Recurrent Neural Network with Attention Mechanism and Multi-task Learning
Relational Differential Dynamic Logic
International audienceIn the field of quality assurance of hybrid systems (that combine continuous physical dynamics and discrete digital control), Platzer's differential dynamic logic (dL) is widely recognized as a deductive verification method with solid mathematical foundations and sophisticated tool support. Motivated by benchmarks provided by our industry partner , we study a relational extension of dL, aiming to formally prove statements such as "an earlier deployment of the emergency brake decreases the collision speed." A main technical challenge here is to relate two states of two dynamics at different time points. Our main contribution is a theory of suitable relational differential invariants (a relational extension of differential invariants that are central proof methods in dL), and a derived technique of time stretching. The latter features particularly high applicability, since the user does not have to synthesize a relational differential invariant out of the air. We derive new inference rules for dL from these notions, and demonstrate their use over a couple of automotive case studies
Relational Differential Dynamic Logic
In the field of quality assurance of hybrid systems (that combine continuous
physical dynamics and discrete digital control), Platzer's differential dynamic
logic (dL) is widely recognized as a deductive verification method with solid
mathematical foundations and sophisticated tool support. Motivated by
benchmarks provided by our industry partner, we study a relational extension of
dL, aiming to formally prove statements such as "an earlier deployment of the
emergency brake decreases the collision speed." A main technical challenge here
is to relate two states of two dynamics at different time points. Our main
contribution is a theory of suitable simulations (a relational extension of
differential invariants that are central proof methods in dL), and a derived
technique of time stretching. The latter features particularly high
applicability, since the user does not have to synthesize a simulation out of
the air. We derive new inference rules for dL from these notions, and
demonstrate their use over a couple of automotive case studies
Phonon Transmission Rate, Fluctuations, and Localization in Random Semiconductor Superlattices: Green's Function Approach
We analytically study phonon transmission and localization in random
superlattices by using a Green's function approach. We derive expressions for
the average transmission rate and localization length, or Lyapunov exponent, in
terms of the superlattice structure factor. This is done by considering the
backscattering of phonons, due to the complex mass density fluctuations, which
incorporates all of the forward scattering processes. These analytical results
are applied to two types of random superlattices and compared with numerical
simulations based on the transfer matrix method. Our analytical results show
excellent agreement with the numerical data. A universal relation for the
transmission fluctuations versus the average transmission is derived
explicitly, and independently confirmed by numerical simulations. The transient
of the distribution of transmission to the log-normal distribution for the
localized phonons is also studied.Comment: 36 pages, Late
韓国における移民関連施策および支援状況に関する実態調査報告(4)
韓国では近年,移民受入れが進み,それに伴って移民政策も急速に整備されてきている。本稿は2010年9月に科学研究費補助金により,日本語教育保障法研究会で実施した韓国における移民関連施策および移民支援の状況に関する現地実態調査の報告後編であり,2009年度調査の報告書から通算すると第4号となる。本稿は,「朝鮮日報」(第2章),「中央日報」(第3章),「韓国日報」(第4章),「戸田郁子氏」(第5章)に対する聞き取り調査報告,および「2009年度,2010年度の韓国現地実態調査から」(第6章)によって構成される
イショセイ シボウ ト 2ガタ トウニョウビョウ シンゾウ ケッカンビョウ
There is evidence supporting the notion that excess abdominal fat is predictive of insulin resistance and the presence of related metabolic abnormalities currently referred to as the metabolic syndrome (MetS). Despite the fact that abdominal obesity is a highly prevalent feature of MetS, the mechanisms by which abdominal obesity is causally related to MetS are not fully elucidated. Besides visceral fat accumulation, ectopic lipid deposition, especially in the liver and skeletal muscle, has been implicated in the pathophysiology of diabetes, insulin resistance and obesity-related disorders. In addition, ectopic fat deposition play a critical role in the heart components such as (1) circulatory and locally recruited fat, (2) intra-and extra-myocellular fat, (3) perivascular fat, and (4) pericardial fat. In this review, the contribution of ectopic lipid deposition to global cardiometabolic risk is discussed via possible mechanisms including adipocytokine, insulin resistance and lipotoxicity
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