3,663 research outputs found
The applicability of the catalytic wet-oxidation to CELSS
The wet oxidation catalysis of Au, Pd, Pt, Rh or Ru on a ceramic honeycomb carrier was traced in detail by 16 to 20 repetitive batch tests each. As a result, Pt or Pd on a honeycomb carrier was shown to catalyze complete nitrogen gasification as N2. Though the catalysts which realize both complete nitrogen gasification and complete oxidation could not be found, the Ru+Rh catalyst was found to be most promising. Ru honeycomb catalyzed both nitrification and nitrogen gasification
Unusual Tunneling Characteristics of Double-quantum-well Heterostructures
We report tunneling phenomena in double InGaAs quantum-well
structures that are at odds with the conventional parallel-momentum-conserving
picture of tunneling between two-dimensional systems. We found that the
tunneling current was mostly determined by the correlation between the emitter
and the state in one well, and not by that between those in both wells. Clear
magnetic-field-dependent features were first observed before the main
resonance, corresponding to tunneling channels into the Landau levels of the
well near the emitter. These facts provide evidence of the violation of
in-plane momentum conservation in two-dimensional systems.Comment: Submitted to ICPS-27 conference proceeding as a contributed pape
Domain walls with non-Abelian orientational moduli
Domain walls with non-Abelian orientational moduli are constructed in U(N)
gauge theories coupled to Higgs scalar fields with degenerate masses. The
associated global symmetry is broken by the domain walls, resulting in the
Nambu-Goldstone (and quasi-Nambu-Goldstone) bosons, which form the non-Abelian
orientational moduli. As walls separate, the wave functions of the non-Abelian
orientational moduli spread between domain walls. By taking the limit of Higgs
mass differences to vanish, we clarify the convertion of wall position moduli
into the non-Abelian orientational moduli. The moduli space metric and its
Kahler potential of the effective field theory on the domain walls are
constructed. We consider two models: a U(1) gauge theory with several charged
Higgs fields, and a U(N) gauge theory with 2N Higgs fields in the fundamental
representation. More details are found in our paper published in Phys. Rev. D77
(2008) 125008 [arXiv:0802.3135 [hep-th]].Comment: contribution to the Proceedings of he 1st MCCQG conference at Crete,
sept. 2009, to appear in Journal of Physics: Conference Series of IO
Perbandingan Prestasi Belajar antara Siswa yang Mendapatkan Pembelajaran Matematika Berbasis Karakter dengan Konvensional
In this paper, we compared two models of learning is a model-based learning and conventional teaching character to see how far these two learning models are instrumental in improving both student achievement or change in the character of students. Researchers want to see whether the learning ability of students get the learning model based character better than those getting conventional model?. Methods that researchers use to determine the extent to which the success of student learning and the changing character of both the gain and the character-based models that get a conventional model
An Application of Kerr Blackhole Fly-Wheel Model to Statistical Properties of QSOs/AGNs
The aim of this work is to demonstrate the properties of the magnetospheric
model around Kerr blackholes (BHs), so-called the fly-wheel (rotation driven)
model. The fly-wheel engine of the BH-accretion disk system is applied to the
statistics of QSOs/AGNs. In the model, the central BH is assumed to be formed
at and obtains nearly maximum but finite rotation energy (
extreme Kerr BH) at the formation stage. The inherently obtained rotation
energy of the Kerr BH is released through an magnetohydrodynamic process. This
model naturally leads finite lifetime of AGN activity.
Nitta et al. (1991) clarified individual evolution of Kerr BH fly-wheel
engine which is parametrized by BH mass, initial Kerr parameter, magnetic field
near the horizon and a dimension-less small parameter. We impose a statistical
model for the initial mass function (IMF) of ensemble of BHs by the
Press-Schechter formalism. By the help of additional assumptions, we can
discuss the evolution of the luminosity function and the spatial number density
of QSOs/AGNs.Comment: 12 pages, 7 figures Fig.7 has been replace
Effect of exchange interaction on fidelity of quantum state transfer from a photon qubit to an electron-spin qubit
We analyzed the fidelity of the quantum state transfer (QST) from a
photon-polarization qubit to an electron-spin-polarization qubit in a
semiconductor quantum dot, with special attention to the exchange interaction
between the electron and the simultaneously created hole. In order to realize a
high-fidelity QST we had to separate the electron and hole as soon as possible,
since the electron-hole exchange interaction modifies the orientation of the
electron spin. Thus, we propose a double-dot structure to separate the electron
and hole quickly, and show that the fidelity of the QST can reach as high as
0.996 if the resonant tunneling condition is satisfied.Comment: 5 pages, 4 figures, to be published in Phys. Rev. B Rapid
Communication
Aharonov-Bohm Oscillations with Spin: Evidence for Berry's Phase
We report a study of the Aharonov-Bohm effect, the oscillations of the
resistance of a mesoscopic ring as a function of a perpendicular magnetic
field, in a GaAs two-dimensional hole system with a strong spin-orbit
interaction. The Fourier spectra of the oscillations reveal extra structure
near the main peak whose frequency corresponds to the magnetic flux enclosed by
the ring. A comparison of the experimental data with results of simulations
demonstrates that the origin of the extra structure is the geometric (Berry)
phase acquired by the carrier spin as it travels around the ring.Comment: To be published in Physical Review Letter
Spin-dependent (magneto)transport through a ring due to spin-orbit interaction
Electron transport through a one-dimensional ring connected with two external
leads, in the presence of spin-orbit interaction (SOI) of strength \alpha and a
perpendicular magnetic field is studied. Applying Griffith's boundary
conditions we derive analytic expressions for the reflection and transmission
coefficients of the corresponding one-electron scattering problem. We
generalize earlier conductance results by Nitta et al. [Appl. Phys. Lett. 75,
695 (1999)] and investigate the influence of \alpha, temperature, and a weak
magnetic field on the conductance. Varying \alpha and temperature changes the
position of the minima and maxima of the magnetic-field dependent conductance,
and it may even convert a maximum into a minimum and vice versa.Comment: 19 pages, 9 figure
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