10,886 research outputs found
Instrumentation of a high-sensitivity microwave vector detection system for low-temperature applications
We present the design and the circuit details of a high-sensitivity microwave
vector detection system, which is aiming for studying the low-dimensional
electron system embedded in the slots of a coplanar waveguide at low
temperatures. The coplanar waveguide sample is placed inside a phase-locked
loop; the phase change of the sample may cause a corresponding change in the
operation frequency, which can be measured precisely. We also employ a
double-pulse modulation on the microwave signals, which comprises a fast pulse
modulation for gated averaging and a slow pulse modulation for lock-in
detection. In measurements on real samples at low temperatures, this system
provides much better resolutions in both amplitude and phase than most of the
conventional vector analyzers at power levels below -65 dBm.Comment: 7 pages, 11 figures, 1 table, lette
Analytical technique for simplification of the encoder-decoder circuit for a perfect five-qubit error correction
Simpler encoding and decoding networks are necessary for more reliable
quantum error correcting codes (QECCs). The simplification of the
encoder-decoder circuit for a perfect five-qubit QECC can be derived
analytically if the QECC is converted from its equivalent one-way entanglement
purification protocol (1-EPP). In this work, the analytical method to simplify
the encoder-decoder circuit is introduced and a circuit that is as simple as
the existent simplest circuits is presented as an example. The encoder-decoder
circuit presented here involves nine single- and two-qubit unitary operations,
only six of which are controlled-NOT (CNOT) gates
A Study on the Relationship Among Brand Image, Service Quality, Customer Satisfaction, and Customer Loyalty â Taking âthe Bao Wei Zhen Catering Teamâ As an Empirical Study
This research focused on the industries of catering services and took the Bao Wei Zhen Catering Team, for example, to explore the relationship between âbrand imageâ, âservice qualityâ, âcustomer satisfactionâ, and âcustomer loyaltyâ. It was meant to found out the important factors affecting consumer satisfaction and the words of mouth. From this research, it could be found that service quality exerted very important influence on the culture of traditional catering services. That was to say when service quality was good, not only the brand image could be improved but also customer satisfaction would be enhanced. Therefore, if it was necessary to further improve the competitiveness of traditional catering service industries, the improvement of service quality was required. Through the improvement of service quality, the current plight faced by the culture of catering services could be effectively improved.
Keywords: brand image, service quality, customer satisfaction, customer loyalty, catering tea
The Ultraluminous X-ray Sources near the Center of M82
We report the identification of a recurrent ultraluminous X-ray source (ULX),
a highly absorbed X-ray source (possibly a background AGN), and a young
supernova remnant near the center of the starburst galaxy M82. From a series of
Chandra observations taken from 1999 to 2005, we found that the transient ULX
first appeared in 1999 October. The source turned off in 2000 January, but
later reappeared and has been active since then. The X-ray luminosity of this
source varies from below the detection level (~2.5e38 erg/s) to its active
state in between ~7e39 erg/s and 1.3e40 erg/s (in the 0.5-10 keV energy band)
and shows unusual spectral changes. The X-ray spectra of some Chandra
observations are best fitted with an absorbed power-law model with photon index
ranging from 1.3 to 1.7. These spectra are similar to those of Galactic black
hole binary candidates seen in the low/hard state except that a very hard
spectrum was seen in one of the observations. By comparing with near infrared
images taken with the Hubble Space Telescope, the ULX is found to be located
within a young star cluster. Radio imaging indicates that it is associated with
a H II region. We suggest that the ULX is likely to be a > 100 solar mass
intermediate-mass black hole in the low/hard state. In addition to the
transient ULX, we also found a highly absorbed hard X-ray source which is
likely to be an AGN and an ultraluminous X-ray emitting young supernova remnant
which may be related to a 100-year old gamma-ray burst event, within 2 arcsec
of the transient ULX.Comment: 9 pages, 8 figures. Accepted for publication in Ap
Hamiltonian and measuring time for analog quantum search
We derive in this study a Hamiltonian to solve with certainty the analog
quantum search problem analogue to the Grover algorithm. The general form of
the initial state is considered. Since the evaluation of the measuring time for
finding the marked state by probability of unity is crucially important in the
problem, especially when the Bohr frequency is high, we then give the exact
formula as a function of all given parameters for the measuring time.Comment: 5 page
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