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Compact and Broadband Microstrip-Line-Fed Modified Rhombus Slot Antenna
The printed microstrip-line-fed broadband rhombus slot antenna is investigated in this paper. With the use of the offset microstrip feed line and the corner-truncated protruded ground plane, the bandwidth enhancement and the slot size reduction for the proposed slot antenna can be obtained. The experimental results demonstrate that the impedance bandwidth for 10 dB return loss reaches 5210 MHz (108.2%, 2210-7420 MHz), which is about 2.67 times of a conventional microstrip-line-fed rhombus slot antenna. This bandwidth can provide with the wireless communication services operating in wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) bands. Under the use of the protruded ground plane, the slot size can be reduced by about 52%. Details of simulated and measured results are presented and discussed
Superconducting screening on different length scales in high-quality bulk MgB2 superconductor
High quality bulk MgB2 exhibit a structure of voids and agglomeration of
crystals on different length-scales. Because of this, the superconducting
currents percolate between the voids in the ensuing structure. Magnetic
measurements reveal that the superconducting currents circulate on at least
three different length-scales, of ~1 micrometre, ~10 micrometre and whole of
the sample (~millimetre). Each of these screenings contributes to the measured
irreversible magnetic moment (Dm). The analysis of the field dependence of Dm
for samples of subsequently decreasing size showed that the critical current
obtained using the simple critical state model is erroneous. This leads to the
artefact of the sample size-dependent critical current and irreversibility
field. Our data analysis enables the separation of the contribution of each of
the screening currents to Dm. The field dependence of each of the currents
follows a stretched exponential form. The currents flowing around whole of the
sample give a dominant contribution to Dm in the intermediate fields (1T < H <
4T at 20K) and they can be used to obtain the value of Jc from critical state
model, which corresponds to the transport Jc
The induced representations of Brauer algebra and the Clebsch-Gordan coefficients of SO(n)
Induced representations of Brauer algebra from with are discussed. The induction coefficients
(IDCs) or the outer-product reduction coefficients (ORCs) of with up to a normalization factor are
derived by using the linear equation method. Weyl tableaus for the
corresponding Gel'fand basis of SO(n) are defined. The assimilation method for
obtaining CG coefficients of SO(n) in the Gel'fand basis for no modification
rule involved couplings from IDCs of Brauer algebra are proposed. Some
isoscalar factors of for the resulting irrep
with
$\sum\limits_{i=1}^{4}\lambda_{i}\leq .Comment: 48 pages latex, submitted to Journal of Phys.
Temperature determination from the lattice gas model
Determination of temperature from experimental data has become important in
searches for critical phenomena in heavy ion collisions. Widely used methods
are ratios of isotopes (which rely on chemical and thermal equilibrium),
population ratios of excited states etc. Using the lattice gas model we propose
a new observable: where is the charge multiplicity and
is the charge of the fragmenting system. We show that the reduced multiplicity
is a good measure of the average temperature of the fragmenting system.Comment: 11 pages, 2 ps file
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