A new measurement of thermal conductivity of amorphous ice and its implications for the thermal evolution of comets

Very slowly deposited amorphous ice has a thermal conductivity about four orders of magnitude or more smaller than hitherto estimated. Using the exceedingly low value of the thermal conductivity of comets deduced from the properties of amorphous ice leads to the expectation that internal heating of comets is negligible below the outer several tens of centimeters

Numerical study of parametric pumping current in mesoscopic systems in the presence of a magnetic field

We numerically study the parametric pumped current when magnetic field is applied both in the adiabatic and nonadiabatic regimes. In particular, we investigate the nature of pumped current for systems with resonance as well as antiresonance. It is found that, in the adiabatic regime, the pumped current changes sign across the sharp resonance with long lifetime, while the nonadiabatic pumped current at finite frequency does not. When the lifetime of the resonant level is short, the behaviors of the adiabatic and nonadiabatic pumped currents are similar with sign changes. Our results show that, at the energy where complete transmission occurs, the adiabatic pumped current is zero, while the nonadiabatic pumped current is nonzero. Different from the resonant case, both the adiabatic and nonadiabatic pumped currents are zero at antiresonance with complete reflection. We also investigate the pumped current when the other system parameters such as magnetic field, pumped frequency, and pumping potentials are varied. Interesting behaviors are revealed. Finally, we study the symmetry relation of the pumped current for several systems with different spatial symmetries upon reversal of magnetic field. Different from the previous theoretical prediction, we find that a system with general inversion symmetry can pump out a finite current in both the adiabatic and nonadiabatic regimes with an approximate relation I(B)I(-B) at small magnetic field. It has been shown theoretically that for systems with reflection symmetry, the pumped current satisfies the relation I(B)=I(-B) in the adiabatic regime. Our results show that even for systems evolving from the inversion to reflection symmetry, the pumped current still obeys the relation I(B)=I(-B) in the adiabatic regime at small magnetic field. © 2011 American Physical Society.published_or_final_versio

Quantum generalized Reed-Solomon codes: Unified framework for quantum MDS codes

We construct a new family of quantum MDS codes from classical generalized Reed-Solomon codes and derive the necessary and sufficient condition under which these quantum codes exist. We also give code bounds and show how to construct them analytically. We find that existing quantum MDS codes can be unified under these codes in the sense that when a quantum MDS code exists, then a quantum code of this type with the same parameters also exists. Thus as far as is known at present, they are the most important family of quantum MDS codes.Comment: 9 pages, no figure

More Straightforward Extraction of the Fundamental Lepton Mixing Parameters from Long-Baseline Neutrino Oscillations

We point out the simple reversibility between the fundamental neutrino mixing parameters in vacuum and their effective counterparts in matter. The former can therefore be expressed in terms of the latter, allowing more straightforward extraction of the genuine lepton mixing quantities from a variety of long-baseline neutrino oscillation experiments. In addition to the parametrization-independent results, we present the formulas based on the standard parametrization of the lepton flavor mixing matrix and give a typical numerical illustration.Comment: RevTex 10 pages. Minor changes. Phys. Rev. D in printin

Exponential asymptotics for time-space Hamiltonians

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High-Accuracy Self-Calibration for Smart, Optical Orbiting Payloads Integrated with Attitude and Position Determination.

A high-accuracy space smart payload integrated with attitude and position (SSPIAP) is a new type of optical remote sensor that can autonomously complete image positioning. Inner orientation parameters (IOPs) are a prerequisite for image position determination of an SSPIAP. The calibration of IOPs significantly influences the precision of image position determination of SSPIAPs. IOPs can be precisely measured and calibrated in a laboratory. However, they may drift to a significant degree because of vibrations during complicated launches and on-orbit functioning. Therefore, laboratory calibration methods are not suitable for on-orbit functioning. We propose an on-orbit self-calibration method for SSPIAPs. Our method is based on an auto-collimating dichroic filter combined with a micro-electro-mechanical system (MEMS) point-source focal plane. A MEMS procedure is used to manufacture a light transceiver focal plane, which integrates with point light sources and a complementary metal oxide semiconductor (CMOS) sensor. A dichroic filter is used to fabricate an auto-collimation light reflection element. The dichroic filter and the MEMS point light sources focal plane are integrated into an SSPIAP so it can perform integrated self-calibration. Experiments show that our method can achieve micrometer-level precision, which is good enough to complete real-time calibration without temporal or spatial limitations

Strong decays of heavy baryons in Bethe-Salpeter formalism

In this paper we study the properties of diquarks (composed of $u$ and/or $d$ quarks) in the Bethe-Salpeter formalism under the covariant instantaneous approximation. We calculate their BS wave functions and study their effective interaction with the pion. Using the effective coupling constant among the diquarks and the pion, in the heavy quark limit $m_Q\to\infty$, we calculate the decay widths of $\Sigma_Q^{(*)}$ ($Q=c,b$) in the BS formalism under the covariant instantaneous approximation and then give predictions of the decay widths $\Gamma(\Sigma_b^{(*)}\to\Lambda_b+\pi)$.Comment: 41 pages, 1 figure, LaTex2e, typos correcte

Flavor violating decays of the Higgs bosons in the THDM-III

We calculate the branching ratios for the decays of neutral Higgs bosons ($h^{0},H^{0},A^{0}$) into pairs of fermions, including flavor violating processes, in the context of the General Two Higgs Doublet Model III.Comment: 23 pages, 10 figures, 6 tables. Text clarifying equations and references added, typos correction

Identification of the relationship between Chinese Adiantum reniforme var. sinense and Canary Adiantum reniforme

© 2014 Wang et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated