10,097 research outputs found
Fermion Pairing across a Dipolar Interaction Induced Resonance
It is known from the solution of the two-body problem that an anisotropic
dipolar interaction can give rise to s-wave scattering resonances, which are
named as dipolar interaction induced resonaces (DIIR). In this letter, we study
zero-temperature many-body physics of a two-component Fermi gas across a DIIR.
In the low-density regime, it is very striking that the resulting pairing order
parameter is a nearly isotropic singlet pairing and the physics can be well
described by an s-wave resonant interaction potential with finite range
corrections, despite of the anisotropic nature of dipolar interaction. The
pairing energy is as strong as a unitary Fermi gas nearby a magnetic Feshbach
resonance. In the high density regime, the anisotropic effect plays an
important role. We find phase transitions from singlet pairing to a state with
mixed singlet and triplet pairing, and then from mixed pairing to pure triplet
pairing. The state with mixed pairing spontaneously breaks the time-reversal
symmetry.Comment: 4.5 pages, 4 figures, figures updated, minor changes in tex
Quantum-classical transition for an analog of double-slit experiment in complex collisions: Dynamical decoherence in quantum many-body systems
We study coherent superpositions of clockwise and anti-clockwise rotating
intermediate complexes with overlapping resonances formed in bimolecular
chemical reactions. Disintegration of such complexes represents an analog of
famous double-slit experiment. The time for disappearance of the interference
fringes is estimated from heuristic arguments related to fingerprints of
chaotic dynamics of a classical counterpart of the coherently rotating complex.
Validity of this estimate is confirmed numerically for the H+D chemical
reaction. Thus we demonstrate the quantum--classical transition in temporal
behavior of highly excited quantum many-body systems in the absence of external
noise and coupling to an environment.Comment: 5 pages, 2 ps color figures. Accepted for publication in Phys. Rev.
Análisis de volátiles mediante GC-MS de aceites esenciales de canela extraĂdos por diferentes mĂ©todos
Cinnamon essential oil (CEO) was extracted by three different methods: steam distillation (SD), ultrasound-assisted steam distillation (UASD) and microwave-assisted steam distillation (MASD). The volatiles in CEO were separated and identified by gas chromatography–mass spectrometry (GC-MS), and the differences in volatiles among the three different methods were further analyzed through principal component analysis. The results showed that 36 individual volatile components were present in the CEO from the three different methods. In general, the numbers of aldehydes, esters, alcohols, terpenes, aromatics and ketones were 6, 3, 7, 17, 2, and 1, respectively. The most abundant volatile component was determined to be cinnamic aldehyde. The content of total cinnamic aldehydes, which determines the price of CEO, was the highest among the three methods in the UASD sample (85.633%). Moreover, the highest yield (8.33‰) of essential oil was extracted by the UASD method. Therefore, UASD was the best way for CEO extraction in this research and was recommended for future industrial applications.El aceite esencial de canela (AEC) se extrajo mediante tres mĂ©todos diferentes: destilaciĂłn al vapor (DV), destilaciĂłn al vapor asistida por ultrasonido (DVAU) y destilaciĂłn al vapor asistida por microondas (DVAM). Los volátiles del AEC se separaron e identificaron mediante cromatografĂa de gases-espectrometrĂa de masas (GC-MS), las diferencias de los volátiles entre los tres mĂ©todos se analizaron adicionalmente a travĂ©s del análisis de componentes principales. Los resultados mostraron la presencia de 36 componentes volátiles en el AEC mediante los tres mĂ©todos diferentes. En general, el nĂşmero de aldehĂdos, Ă©steres, alcoholes, terpenos, aromáticos y cetonas presentes fue de 6, 3, 7, 17, 2 y 1, respectivamente. Se determinĂł que el componente volátil más abundante era el aldehĂdo cinámico. El contenido de aldehĂdo cinámico total, el cual decide el precio del AEC, en la muestra de DVAU (85,633%), fue el más alto entre tres mĂ©todos. Además, el mayor rendimiento (8,33‰) de aceite esencial se encontrĂł mediante el mĂ©todo DVAU. Por lo tanto, DVAU fue la mejor forma de extracciĂłn de AEC en esta investigaciĂłn y se recomienda en futuras aplicaciones industriales
On the mass relation of a meson nonet
It is pointed out that the omission of the effects of the transition between
quarkonia or the assumption that the transition between quarkonia is
flavor-independent would result in the inconsistent results for the
pseudoscalar meson nonet. It is emphasized that the mass relation of the
non-ideal mixing meson nonets should incorporate the effects of the
flavor-dependent transition between quarkonia. The new mass relations of a
meson nonet are presented.Comment: Latex, 10 pages, to appear in Mod. Phys. Lett.
Accurate prediction of protein function using statistics-informed graph networks
Understanding protein function is pivotal in comprehending the intricate mechanisms that underlie many crucial biological activities, with far-reaching implications in the fields of medicine, biotechnology, and drug development. However, more than 200 million proteins remain uncharacterized, and computational efforts heavily rely on protein structural information to predict annotations of varying quality. Here, we present a method that utilizes statistics-informed graph networks to predict protein functions solely from its sequence. Our method inherently characterizes evolutionary signatures, allowing for a quantitative assessment of the significance of residues that carry out specific functions. PhiGnet not only demonstrates superior performance compared to alternative approaches but also narrows the sequence-function gap, even in the absence of structural information. Our findings indicate that applying deep learning to evolutionary data can highlight functional sites at the residue level, providing valuable support for interpreting both existing properties and new functionalities of proteins in research and biomedicine
Modification of Kawai model about the mixing of the pseudoscalar mesons
The Kawai model describing the glueball-quarkonia mixing is modified. The
mixing of , and is re-investigated based on
the modified Kawai model. The glueball-quarkonia content of the three states is
determined from a fit to the data of the electromagnetic decays involving
, . Some predictions about the electromagnetic decays
involving are presented.Comment: revtex 8 page
Mutual-Chern-Simons effective theory of doped antiferromagnets
A mutual-Chern-Simons Lagrangian is derived as a minimal field theory
description of the phase-string model for doped antiferromagnets. Such an
effective Lagrangian is shown to retain the full symmetries of parity,
time-reversal, and global SU(2) spin rotation, in contrast to conventional
Chern-Simons theories where first two symmetries are usually broken. Two
ordered phases, i.e., antiferromagnetic and superconducting states, are found
at low temperatures as characterized by dual Meissner effects and dual flux
quantization conditions due to the mutual-Chern-Simons gauge structure. A dual
confinement in charge/spin degrees of freedom occurs such that no true
spin-charge separation is present in these ordered phases, but the spin-charge
separation/deconfinement serves as a driving force in the unconventional phase
transitions of these ordered states to disordered states.Comment: 16 pages, 2 figures; published versio
Reflected Schr\"odinger Bridge for Constrained Generative Modeling
Diffusion models have become the go-to method for large-scale generative
models in real-world applications. These applications often involve data
distributions confined within bounded domains, typically requiring ad-hoc
thresholding techniques for boundary enforcement. Reflected diffusion models
(Lou23) aim to enhance generalizability by generating the data distribution
through a backward process governed by reflected Brownian motion. However,
reflected diffusion models may not easily adapt to diverse domains without the
derivation of proper diffeomorphic mappings and do not guarantee optimal
transport properties. To overcome these limitations, we introduce the Reflected
Schrodinger Bridge algorithm: an entropy-regularized optimal transport approach
tailored for generating data within diverse bounded domains. We derive elegant
reflected forward-backward stochastic differential equations with Neumann and
Robin boundary conditions, extend divergence-based likelihood training to
bounded domains, and explore natural connections to entropic optimal transport
for the study of approximate linear convergence - a valuable insight for
practical training. Our algorithm yields robust generative modeling in diverse
domains, and its scalability is demonstrated in real-world constrained
generative modeling through standard image benchmarks
An anatomical study of the origin, structure and insertion of the medial patellofemoral ligament
Background: Repair and reconstruction of the medial patellofemoral ligament (MPFL) has been undertaken for the treatment of patellar instability. For successful surgery detailed knowledge of the anatomy of the ligament is required. The aim of this study was to describe the origin, structure and insertion of the MPFL.
Materials and methods: We studied cadaveric knees from 30 Chinese adults. We studied the origin, course and insertion of the MPFL.
Results: We found that the MPFL was composed of two main strands, superficial and deep. We also found that the insertion of the MPFL into the femur had three common patterns. All three were located between the adductor tubercle and the proximal part of superficial medial collateral ligament.
Conclusions: We have added to the anatomical knowledge of the structure of the MPFL. Our study has implications for guiding bone tunnel positioning during MPFL reconstruction surgery. (Folia Morphol 2018; 77, 2: 356–361
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