4,860 research outputs found
Hierarchical clustering and formation of power-law correlation in 1-dimensional self-gravitating system
The process of formation of fractal structure in one-dimensional
self-gravitating system is examined numerically. It is clarified that
structures created in small spatial scale grow up to larger scale through
clustering of clusters, and form power-law correlation.Comment: 9pages,4figure
Non(anti)commutative superspace with coordinate-dependent deformation
We consider non(anti)commutative superspace with coordinate dependent
deformation parameters . We show that a chiral
supersymmetry can be defined and that chiral and antichiral superfields are
still closed under the Moyal-Weyl associative product implementing the
deformation. A consistent Super Yang-Mills deformed theory can
be constructed provided satisfies a suitable condition which
can be connected with the graviphoton background at the origin of the
deformation. After adding matter we also discuss the Konishi anomaly and the
gluino condensation.Comment: References added. Accepted for publication in PR
Self-Organized Bottleneck in Energy Relaxation
We study an energy relaxation process after many degrees of freedom are
excited in a Hamiltonian system with a large number of degrees of freedom.
Bottlenecks of relaxation, where relaxations of the excited elements are
drastically slowed down, are discovered. By defining an internal state for the
excited degrees of freedom, it is shown that the drastic slowing down occurs
when the internal state is in a critical state. The relaxation dynamics brings
the internal state into the critical state, and the critical bottleneck of
relaxation is self-organized. Relevance of our result to relaxation phenomena
in condensed matters or large molecules is briefly discussed.Comment: 4pages, 5 figure
Structure of Metastable States in Phase Transitions with High-Spin Low-Spin Degree of Freedom
Difference of degeneracy of the low-spin (LS) and high-spin (HS) states
causes interesting entropy effects on spin-crossover phase transitions and
charge transfer phase transitions in materials composed of the spin-crossover
atoms. Mechanisms of the spin-crossover (SC) phase transitions have been
studied by using Wajnflasz model, where the degeneracy of the spin states (HS
or LS) is taken into account and cooperative natures of the spin-crossover
phase transitions have been well described. Recently, a charge transfer (CT)
phase transition due to electron hopping between LS and HS sites has been
studied by using a generalized Wajnflasz model. In the both systems of SC and
CT, the systems have a high temperature structure (HT) and a low temperature
structure (LT), and the change between them can be a smooth crossover or a
discontinuous first order phase transition depending on the parameters of the
systems. Although apparently the standard SC system and the CT system are very
different, it is shown that both models are equivalent under a certain
transformation of variables. In both systems, the structure of metastable state
at low temperatures is a matter of interest. We study temperature dependence of
fraction of HT systematically in a unified model, and find several structures
of equilibrium and metastable states of the model as functions of system
parameters. In particular, we find a reentrant type metastable branch of HT in
a low temperature region, which would play an important role to study the
photo-irradiated processes of related materials.Comment: 19 pages, 11 figure
Circularly-Polarized Light Emission from Semiconductor Planar Chiral Photonic Crystal
We proposed and demonstrated a scheme of surface emitting circularly
polarized light source by introducing strong imbalance between left- and
right-circularly polarized vacuum fields in an on-waveguide chiral grating
structure. We observed circularly polarized spontaneous emission from InAs
quantum dots embedded in the wave guide region of a GaAs-based structure.
Obtained degree of polarization reaches as large as 25% at room temperature.
Numerical calculation visualizes spatial profiles of the modification of vacuum
field modes inside the structure with strong circular anisotropy.Comment: REVTeX4.1, 6pages, 3figure
Fundamental and clinical evaluation of "SCC RIABEAD" kit for immuno radiometric assay of squamous cell carcinoma related antigen.
Classic vector control strategies target mosquitoes indoors as the main transmitters of malaria are indoor-biting and –resting mosquitoes. However, the intensive use of insecticide-treated bed-nets (ITNs) and indoor residual spraying have put selective pressure on mosquitoes to adapt in order to obtain human blood meals. Thus, early-evening and outdoor vector activity is becoming an increasing concern. This study assessed the effect of a deltamethrin-treated net (100 mg/m2) attached to a one-meter high fence around outdoor cattle enclosures on the number of mosquitoes landing on humans. Mosquitoes were collected from four cattle enclosures: Pen A – with cattle and no net; B – with cattle and protected by an untreated net; C – with cattle and protected by a deltamethrin-treated net; D – no cattle and no net. A total of 3217 culicines and 1017 anophelines were collected, of which 388 were Anopheles gambiae and 629 An. ziemanni. In the absence of cattle nearly 3 times more An. gambiae (p<0.0001) landed on humans. The deltamethrin-treated net significantly reduced (nearly three-fold, p<0.0001) culicine landings inside enclosures. The sporozoite rate of the zoophilic An. ziemanni, known to be a secondary malaria vector, was as high as that of the most competent vector An. gambiae; raising the potential of zoophilic species as secondary malaria vectors. After deployment of the ITNs a deltamethrin persistence of 9 months was observed despite exposure to African weather conditions. The outdoor use of ITNs resulted in a significant reduction of host-seeking culicines inside enclosures. Further studies investigating the effectiveness and spatial repellence of ITNs around other outdoor sites, such as bars and cooking areas, as well as their direct effect on vector-borne disease transmission are needed to evaluate its potential as an appropriate outdoor vector control tool for rural Africa
RF amplification property of the MgO-based magnetic tunnel junction using field-induced ferromagnetic resonance
The radio-frequency (RF) voltage amplification property of a tunnel
magnetoresistance device driven by an RF external-magnetic-field-induced
ferromagnetic resonance was studied. The proposed device consists of a magnetic
tunnel junction (MTJ) and an electrically isolated coplanar waveguide. The
input RF voltage applied to the waveguide can excite the resonant dynamics in
the free layer magnetization, leading to the generation of an output RF voltage
under a DC bias current. The dependences of the RF voltage gain on the static
external magnetic field strength and angle were systematically investigated.
The design principles for the enhancement of the gain factor are also
discussed.Comment: 12 pages, 3 figure
Confinement in N=1 SQCD: One Step Beyond Seiberg's Duality
We consider N=1 supersymmetric quantum chromodynamics (SQCD) with the gauge
group U(N_c) and N_c+N quark flavors. N_c flavors are massless; the
corresponding squark fields develop (small) vacuum expectation values (VEVs) on
the Higgs branch. Extra N flavors are endowed with small (and equal) mass
terms. We study this theory through its Seiberg's dual: U(N) gauge theory with
N_c +N flavors of "dual quark" fields plus a gauge-singlet mesonic field M. The
original theory is referred to as "quark theory" while the dual one is termed
"monopole theory." The suggested mild deformation of Seiberg's procedure
changes the dynamical regime of the monopole theory from infrared free to
asymptotically free at large distances. We show that, upon condensation of the
"dual quarks," the dual theory supports non-Abelian flux tubes (strings).
Seiberg's duality is extended beyond purely massless states to include light
states on both sides. Being interpreted in terms of the quark theory, the
monopole-theory flux tubes are supposed to carry chromoelectric fields. The
string junctions -- confined monopole-theory monopoles -- can be viewed as
"constituent quarks" of the original quark theory. We interpret closed strings
as glueballs of the original quark theory. Moreover, there are string
configurations formed by two junctions connected by a pair of different
non-Abelian strings. These can be considered as constituent quark mesons of the
quark theory.Comment: 30 pages, 3 figures; v2 a reference added, minor comments added;
final version to be published in PR
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