969 research outputs found
Universal Existence of Exact Quantum State Transmissions in Interacting Media
We consider an exact state transmission, where a density matrix in one
information processor A at time is exactly equal to that in another
processor B at a later time. We demonstrate that there always exists a complete
set of orthogonal states, which can be employed to perform the exact state
transmission. Our result is very general in the sense that it holds for
arbitrary media between the two processors and for any time interval. We
illustrate our results in terms of models of spin, fermionic and bosonic
chains. This complete set can be used as bases to study the perfect state
transfer, which is associated with degenerated subspaces of this set of states.
Interestingly, this formalism leads to a proposal of perfect state transfer via
adiabatic passage, which does not depend on the specific form of the driving
Hamiltonian.Comment: 4 pages, no figur
A 14-mW PLL-less receiver in 0.18-μm CMOS for Chinese electronic toll collection standard
This is the accepted manuscript version of the following article: Xiaofeng He, et al., “A 14-mW PLL-less receiver in 0.18-μm CMOS for Chinese electronic toll collection standard”, IEEE Transactions on Circuits and Systems II: Express Briefs, Vol. 61(10): 763-767, August 2014. The final published version is available at: http://ieeexplore.ieee.org/document/6871304/ © 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The design of a 14-mW receiver without phase-locked loop for the Chinese electronic toll collection (ETC) system in a standard 0.18-μm CMOS process is presented in this brief. Since the previously published work was mainly based on vehicle-powered systems, low power consumption was not the primary goal of such a system. In contrast, the presented system is designed for a battery-powered system. Utilizing the presented receiver architecture, the entire receiver only consumes 7.8 mA, at the supply voltage of 1.8 V, which indicates a power saving of at least 38% compared with other state-of-the-art designs for the same application. To verify the performance, the bit error rate is measured to be better than 10-6, which well satisfies the Chinese ETC standard. Moreover, the sensitivity of the designed receiver can be readjusted to -50 dBm, which is required by the standard.Peer reviewe
Glueball Masses from Hamiltonian Lattice QCD
We calculate the masses of the , and glueballs from
QCD in 3+1 dimensions using an eigenvalue equation method for Hamiltonian
lattice QCD developed and described elsewhere by the authors. The mass ratios
become approximately constants in the coupling region ,
from which we estimate and
.Comment: 12 pages, Latex, figures to be sent upon reques
Effects of alkyl chain length of acrylates on sizing properties of grafted feather keratin
In this study, sizing properties of grafted feather keratin for high polyester content warp yarns have been improved bypreparing a series of feather keratin-g-poly(acrylic acid-co-acrylate) through grafting acrylate monomers with various alkylchain lengths and hydrophilic monomer [acrylic acid (AA)] onto molecular chains of native feather keratin. The feed molarratio of AA/acrylate is kept constant during the preparation. Effects of alkyl chain length of acrylate monomers on sizingproperties of feather keratin-g-poly(acrylic acid-co-acrylate) to polyester/cotton(65/35) blended warp yarns has been studiedin terms of tensile strength & elongation, abrasion resistance, and hairiness. The grafting of acrylates onto the molecularchains of feather keratin significantly improves the sizing properties of grafted feather keratin. With the increase in alkylchain length, the tensile strength, tensile elongation, and abrasion resistance of the sized yarns are improved, while thehairiness amount is increased. Acrylate monomers with different alkyl chain lengths during the preparation of graftedfeather keratin sizes can be selected according to various requirements for high polyester content warp yarns
Modeling spatial-temporal change of Poyang Lake marshland based on an uncertainty theory - random sets
AbstractUncertainty modeling now engages the attention of researchers in spatial temporal change analysis in remote sensing. Some studies proposed to use random sets for modeling the spatial uncertainty of image objects with uncertain boundaries, but none have considered the parameter determination problem for large datasets. In this paper we refined the random set models for monitoring monthly changes in wetland vegetation areas from series of images. Twelve cloud-free HJ-1A/1B images from April 2009 to March 2010 were used for monitoring spatial-temporal changes of Poyang Lake wetlands. We applied random sets to represent spatial uncertainty of wetland vegetation that were extracted from normalized difference vegetation index (NDVI) maps. Time series of random sets reflect the seasonal differences of location and extents of the wetlands, whereas degree of uncertainties indicated by SD and CV indices reflect the gradual change of the wetland vegetation in space. Results show that the uncertain extents of wetland vegetation change through the year, achieving the largest range and uncertainty degree in autumn. This coincides with the highly heterogeneous vegetation status in autumn, since the wetland recovers gradually after flooding and young vegetation emerges at gradually changing densities, thus providing forage in different ecological zones for different types of migratory birds. We conclude that the random set model enriches spatial-temporal modeling of phenomena which are uncertain in space and dynamic in time
Noise suppression of on-chip mechanical resonators by chaotic coherent feedback
We propose a method to decouple the nanomechanical resonator in
optomechanical systems from the environmental noise by introducing a chaotic
coherent feedback loop. We find that the chaotic controller in the feedback
loop can modulate the dynamics of the controlled optomechanical system and
induce a broadband response of the mechanical mode. This broadband response of
the mechanical mode will cut off the coupling between the mechanical mode and
the environment and thus suppress the environmental noise of the mechanical
modes. As an application, we use the protected optomechanical system to act as
a quantum memory. It's shown that the noise-decoupled optomechanical quantum
memory is efficient for storing information transferred from coherent or
squeezed light
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