2,176 research outputs found
Exact solutions to the time-dependent supersymmetric muliphoton Jaynes-Cummings model and the Chiao-Wu model
By using both the Lewis-Riesenfeld invariant theory and the invariant-related
unitary transformation formulation, the present paper obtains the exact
solutions to the time-dependent supersymmetric two-level multiphoton
Jaynes-Cummings model and the Chiao-Wu model that describes the propagation of
a photon inside the optical fiber. On the basis of the fact that the two-level
multiphoton Jaynes-Cummings model possesses the supersymmetric structure, an
invariant is constructed in terms of the supersymmetric generators by working
in the sub-Hilbert-space corresponding to a particular eigenvalue of the
conserved supersymmetric generators (i.e., the time-independent invariant). By
constructing the effective Hamiltonian that describes the interaction of the
photon with the medium of the optical fiber, it is further verified that the
particular solution to the Schr\"{o}dinger equation is the eigenfunction of the
second-quantized momentum operator of photons field. This, therefore, means
that the explicit expression (rather than the hidden form that involves the
chronological product) for the time-evolution operator of wave function is
obtained by means of the invariant theories.Comment: 14 pages, Latex. This is a revised version of the published paper:
Shen J Q, Zhu H Y 2003 Ann. Phys.(Leipzig) Vol.12 p.131-14
A unified approach to exact solutions of time-dependent Lie-algebraic quantum systems
By using the Lewis-Riesenfeld theory and the invariant-related unitary
transformation formulation, the exact solutions of the {\it time-dependent}
Schr\"{o}dinger equations which govern the various Lie-algebraic quantum
systems in atomic physics, quantum optics, nuclear physics and laser physics
are obtained. It is shown that the {\it explicit} solutions may also be
obtained by working in a sub-Hilbert-space corresponding to a particular
eigenvalue of the conserved generator ({\it i. e.}, the {\it time-independent}
invariant) for some quantum systems without quasi-algebraic structures. The
global and topological properties of geometric phases and their adiabatic limit
in time-dependent quantum systems/models are briefly discussed.Comment: 11 pages, Latex. accepted by Euro. Phys. J.
Gravitomagnetic Field and Time-Dependent Spin-Rotation Coupling
The Kerr metric of spherically symmetric gravitational field is analyzed
through the coordinate transformation from the rotating frame to fixing frame,
and consequently that the inertial force field (with the exception of the
centrifugal force field) in the rotating system is one part of its
gravitomagnetic field is verified. We investigate the spin-rotation coupling
and, by making use of Lewis-Riesenfeld invariant theory, we obtain exact
solutions of the Schr\"{o}dinger equation of a spinning particle in a
time-dependent rotating reference frame. A potential application of these exact
solutions to the investigation of Earths rotating frequency fluctuation
by means of neutron-gravity interferometry experiment is briefly discussed in
the present paper.Comment: 6 pages, 0 figures, Late
Comparison of 2.2mm micro incision and 3.0mm incision coaxial phacoemulsification
AIM:To compare the operation effect of 2.2mm micro incision and 3.0mm incision coaxial phacoemulsification.<p>METHODS: Patients with age-related cataract(90 cases, 90 eyes)were enrolled in the study from January 2012 to June 2013 in our hospital, and they were randomly divided into 2 groups: 2.2mm incision group(45 eyes of 45 cases), 3.0mm incision group(45 eyes of 45 cases). Corneal tunnel incision coaxial phacoemulsification was performed. At 1d, 1wk, 1, 3mo after operation, the visual acuity, corneal endothelial cell count, central corneal thickness, operation astigmatism were recorded.<p>RESULTS: One day after operation, the visual acuity of 2.2mm incision group were significantly improved, the difference was statistically significant(<i>P</i><0.05), there were no differences in two groups at 1wk, 1, 3mo after operation. No significant differences between the two groups of corneal endothelial cell counting, central corneal thickness at 1wk, 1, 3mo after operation were observed(<i>P</i>>0.05). Operation source astigmatism had statistically significant difference at 1d, 1wk, 1, 3mo after operation(<i>P</i><0.05), it decreased significantly in the 2.2mm incision group. <p>CONCLUSION: The 2.2mm small incision coaxial phacoemulsification with postoperative visual acuity improved more significantly, can significantly reduce the operation astigmatism
Eight new species of the genera \u3cem\u3eScorpiops\u3c/em\u3e Peters, \u3cem\u3eEuscorpiops\u3c/em\u3e Vachon, and \u3cem\u3eChaerilus\u3c/em\u3e Simon (Scorpiones: Euscorpiidae, Chaerilidae) from Tibet and Yunnan, China
Eight new species belonging to the genera Scorpiops and Euscorpiops (Euscorpiidae: Scorpiopinae) and Chaerilus (Chaerilidae) are described from China. These are: Scorpiops atomatus sp. n., Scorpiops langxian sp. n., Scorpiops luridus sp. n., Scorpiops pococki sp. n., Euscorpiops vachoni sp. n., Euscorpiops shidian sp. n., Euscorpiops karschi sp. n., and Chaerilus tessellatus sp. n. New records are also reported for these three genera, and the taxa are redescribed. Descriptions and redescriptions are based mainly on the material collected in Tibet Autonomous Region and Yunnan Province. Checklists and identification keys for Chinese species of the genus Chaerilus and the subfamily Scorpiopinae are provided
Editorial: Untangle the broad connections and tight interactions between human microbiota and complex diseases through data-driven approaches
It is well-known that microorganisms are ubiquitous in the environment and occupy almost all habitats in animals and humans (Finlay and Clarke, 1999; Rosenberg, 2021). Traditionally, microorganisms are studied as individuals grown in isolation under artificial conditions; however, with the development of experimental techniques and computational methods, microbes are now frequently considered as a functional group in a particular niche and studied at the community level in order to best mimicking the real-world situations (American Academy of Microbiology, 2004). During the study of microbial communities, two terms are commonly used, that is, microbiota and microbiome
Validity of Equation-of-Motion Approach to Kondo Problem in the Large- limit
The Anderson impurity model for Kondo problem is investigated for arbitrary
orbit-spin degeneracy of the magnetic impurity by the equation of motion
method (EOM). By employing a new decoupling scheme, a set self-consistent
equations for the one-particle Green function are derived and numerically
solved in the large- approximation. For the particle-hole symmetric Anderson
model with finite Coulomb interaction , we show that the Kondo resonance at
the impurity site exists for all . The approach removes the pathology
in the standard EOM for N=2, and has the same level of applicability as
non-crossing approximation. For N=2, an exchange field splits the Kondo
resonance into only two peaks, consist with the result from more rigorous
numerical renormalization group (NRG) method. The temperature dependence of the
Kondo resonance peak is also discussed.Comment: 4 pages, 2 eps figure
Cloning and functional analysis in transgenic tobacco of a tapetum-specific promoter from Arabidopsis
The 5’-flanking region of 1174 bp upstream of the translation start point (TSP) of a reported Arabidopsis anther-specific gene, Anther7 gene (ATA7), which putatively encodes a protein related to lipid transfer protein, was cloned and functionally analyzed in transgenic tobacco after been fused with β- glucuronidase (GUS) gene reporter. Histochemical GUS staining of the transgenic plants showed that the cloned fragment did drive GUS expression exclusively in the anther, not in any other parts of floral organs, including pollens and nor in any vegetative tissue. Transverse section of the GUS-blue anthers disclosed that the blue cells were present uniquely in the tapetum of the anther. A series of 5’-deletion of cloned fragment indicated that a short segment of 179 bp upstream of the TSP (-155 bp upstream of the transcription start site) retained not only the promoter’s driving power, but also its tapetum-specificity. Cis-acting element search in this short segment revealed the presence of numbers of organ- and tissuespecific motifs, including pollen-specific LAT52 and SLG13. These results indicated that the tapetumspecificity of ATA7 gene is mainly conferred by its promoter, and such a promoter, in particular, the core one should be useful both for identification of tapetum-involved genes and for biotechnological applications.Key words: Arabidopsis, Anther7 gene of Arabidopsis theliana (ATA7), anther-specific promoter, tapetumspecific promoter
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