29,327 research outputs found
Measurement and Calibration of A High-Sensitivity Microwave Power Sensor with An Attenuator
In this paper, measurement and calibration of a high-sensitivity microwave power sensor through an attenuator is performed using direct comparison transfer technique. To provide reliable results, a mathematical model previously derived using signal flow graphs together with non-touching loop rule analysis for the measurement estimate (i.e. calibration factor) and its uncertainty evaluation is comparatively investigated. The investigation is carried out through the analysis of physical measurement processes, and consistent mathematical model is observed. Later, an example of Type-N (up to 18 GHz) application is used to demonstrate its calibration and measurement capability
Doublet bands in Cs in the triaxial rotor model coupled with two quasiparticles
The positive parity doublet bands based on the configuration in Cs have been investigated in the two
quasi-particles coupled with a triaxial rotor model. The energy spectra ,
energy staggering parameter , and
values, intraband ratios,
ratios, and orientation of the
angular momentum for the rotor as well as the valence proton and neutron are
calculated. After including the pairing correlation, good agreement has been
obtained between the calculated results and the data available, which supports
the interpretation of this positive parity doublet bands as chiral bands.Comment: Phys.Rev.C (accepted
Chiral bands for quasi-proton and quasi-neutron coupling with a triaxial rotor
A particle rotor model (PRM) with a quasi-proton and a quasi-neutron coupled
with a triaxial rotor is developed and applied to study chiral doublet bands
with configurations of a proton and a quasi-neutron. With
pairing treated by the BCS approximation, the present quasi-particle PRM is
aimed at simulating one proton and many neutron holes coupled with a triaxial
rotor. After a detailed analysis of the angular momentum orientations, energy
separation between the partner bands, and behavior of electromagnetic
transitions, for the first time we find aplanar rotation or equivalently chiral
geometry beyond the usual one proton and one neutron hole coupled with a
triaxial rotor.Comment: 25 pages, 10 figures, accepted for publication in Physical Review
The effect of asymmetry of the coil block on self-assembly in ABC coil-rod-coil triblock copolymers
Using the self-consistent field approach, the effect of asymmetry of the coil
block on the microphase separation is focused in ABC coil-rod-coil triblock
copolymers. For different fractions of the rod block , some stable
structures are observed, i.e., lamellae, cylinders, gyroid, and core-shell
hexagonal lattice, and the phase diagrams are constructed. The calculated
results show that the effect of the coil block fraction is
dependent on . When , the effect of asymmetry of
the coil block is similar to that of the ABC flexible triblock copolymers; When
, the self-assembly of ABC coil-rod-coil triblock copolymers
behaves like rod-coil diblock copolymers under some condition. When continues to increase, the effect of asymmetry of the coil block reduces.
For , under the symmetrical and rather asymmetrical
conditions, an increase in the interaction parameter between different
components leads to different transitions between cylinders and lamellae. The
results indicate some remarkable effect of the chain architecture on
self-assembly, and can provide the guidance for the design and synthesis of
copolymer materials.Comment: 9 pages, 3 figure
Mean-field embedding of the dual fermion approach for correlated electron systems
To reduce the rapidly growing computational cost of the dual fermion lattice
calculation with increasing system size, we introduce two embedding schemes.
One is the real fermion embedding, and the other is the dual fermion embedding.
Our numerical tests show that the real fermion and dual fermion embedding
approaches converge to essentially the same result. The application on the
Anderson disorder and Hubbard models shows that these embedding algorithms
converge more quickly with system size as compared to the conventional dual
fermion method, for the calculation of both single-particle and two-particle
quantities.Comment: 10 pages, 10 figure
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