1,780 research outputs found
Interface-induced heavy-hole/light-hole splitting of acceptors in silicon
The energy spectrum of spin-orbit coupled states of individual sub-surface
boron acceptor dopants in silicon have been investigated using scanning
tunneling spectroscopy (STS) at cryogenic temperatures. The spatially resolved
tunnel spectra show two resonances which we ascribe to the heavy- and
light-hole Kramers doublets. This type of broken degeneracy has recently been
argued to be advantageous for the lifetime of acceptor-based qubits [Phys. Rev.
B 88 064308 (2013)]. The depth dependent energy splitting between the heavy-
and light-hole Kramers doublets is consistent with tight binding calculations,
and is in excess of 1 meV for all acceptors within the experimentally
accessible depth range (< 2 nm from the surface). These results will aid the
development of tunable acceptor-based qubits in silicon with long coherence
times and the possibility for electrical manipulation
Key Factors in the Medical Examination Product Design and Development Using Human Cell Image Totems
The industry of cultural creativity has a significant influence on the overall economy of a country. The development and application of cultural and creative products in different fields are growing more diverse. In the field of medicine, cultural and creative products can deliver more than aesthetic functions. They can bring healing benefits for patients with different symptoms in different age groups. Creative product designs that combine medicine and cultural/artistic creativity can make medical products warmer and friendlier to users. Focusing on the creative design of medical examination products, this study aims to provide references for more creative and friendly design of medical examination products to help reduce the fear and anxiety of patients when using such products. In this study, micro images of human cells are converted into totems as design elements for the design and development of cultural and creative products. These image totems not only represent the lively cellular world inside human body but also add aesthetics to the product design and make the products look warmer and friendlier to users. The research methods of literature survey, expert interview survey, and analytic hierarchy process (AHP) to first find out the factors in the medical product design using image totems of human cell mutation and reproduction and then measure the relative weight of each factor. Hopefully, the findings of this study can provide references for the creative design and development of medical examination products and help to enhance the design effectiveness.
Keywords: cultural creativity industry, medical examination, products with healing effects, expert interview, analytic hierarchy process (AHP
Comparative bactericidal activities of daptomycin, glycopeptides, linezolid and tigecycline against blood isolates of Gram-positive bacteria in Taiwan
ABSTRACTIn-vitro MICs and minimum bactericidal concentrations (MBCs) of daptomycin, linezolid, tigecycline, vancomycin and teicoplanin against Gram-positive bacteria were determined using the broth microdilution method for ten blood isolates each of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), including two vancomycin-intermediate S. aureus (VISA), vancomycin-resistant Enterococcus faecium and Enterococcus faecalis. One strain of VISA was tested in a time-kill synergism assay of daptomycin combined with oxacillin, imipenem, rifampicin and isepamicin. Daptomycin showed excellent in-vitro bactericidal activity against all the isolates tested, with no tolerance or synergism effects when combined with other agents, except with rifampicin against VISA. Vancomycin had better bactericidal activity against MRSA and MSSA than did teicoplanin. Linezolid had the poorest bactericidal activity against the isolates tested, with 100% tolerance by the MSSA and VRE isolates, and 80% tolerance by the MRSA isolates. Tolerance towards tigecycline was exhibited by 40% of the MRSA isolates, 100% of the MSSA and vancomycin-resistant E. faecalis isolates, and 90% of the vancomycin-resistant E. faecium isolates
A new approach to axial coupling constants in the QCD sum rule
We derive new QCD sum rules for the axial coupling constants by considering
two-point correlation functions of the axial-vector currents in a one nucleon
state. The QCD sum rules tell us that the axial coupling constants are
expressed by nucleon matrix elements of quark and gluon operators which are
related to the sigma terms and the moments of parton distribution functions.
The results for the iso-vector axial coupling constants and the 8th component
of the SU(3) octet are in good agreement with experiment.Comment: 10 pages, 1 figure include
Flavor and Spin Contents of the Nucleon in the Quark Model with Chiral Symmetry
A simple calculation in the framework of the chiral quark theory of Manohar
and Georgi yields results that can account for many of the ''failures'' of the
naive quark model: significant strange quark content in the nucleon as
indicated by the value of the -
asymmetry in the nucleon as measured by the deviation from Gottfried sum rule
and by the Drell-Yan process, as well as the various quark contributions to the
nucleon spin as measured by the deep inelastic polarized lepton-nucleon
scatterings.Comment: figure has been separated from tex file. No other changes. Preprint
CMU-HEP94-3
Impact of measurement backaction on nuclear spin qubits in silicon
Phosphorus donor nuclear spins in silicon couple weakly to the environment
making them promising candidates for high-fidelity qubits. The state of a donor
nuclear spin qubit can be manipulated and read out using its hyperfine
interaction with the electron confined by the donor potential. Here we use a
master equation-based approach to investigate how the backaction from this
electron-mediated measurement affects the lifetimes of single and multi-donor
qubits. We analyze this process as a function of electric and magnetic fields,
and hyperfine interaction strength. Apart from single nuclear spin flips, we
identify an additional measurement-related mechanism, the nuclear spin
flip-flop, which is specific to multi-donor qubits. Although this flip-flop
mechanism reduces qubit lifetimes, we show that it can be effectively
suppressed by the hyperfine Stark shift. We show that using atomic precision
donor placement and engineered Stark shift, we can minimize the measurement
backaction in multi-donor qubits, achieving larger nuclear spin lifetimes than
single donor qubits
Detecting Action Items in Meetings
Abstract. We present a method for detecting action items in spontaneous meeting speech. Using a supervised approach incorporating prosodic, lexical and structural features, we can classify such items with a high degree of accuracy. We also examine how well various feature subclasses can perform this task on their own.
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