18,539 research outputs found
Inclusion agglomeration in electrified molten metal: thermodynamic consideration
The effect of electric current on inclusion agglomeration in molten metal has been investigated. It is found that the agglomeration is dependent on the electric current density, distance between inclusions and orientation of electric field. Electric current retards the agglomeration unless two inclusions are aligned along or closely to the current flow streamlines and the distance between inclusions is less than a critical value. The mechanism is also validated in the computation of cluster agglomeration. The numerical results provide a comprehensive indication for the current-induced inclusion removal and current-induced inclusion elongation. When the inclusions are in long-thin shape, the calculation predicts the current-induced microstructure alignment and current-induced microstructure refinement phenomena
Combined fit to BaBar and Belle data on e+e- to pi+pi- psi(2S)
A combined fit is performed to the BaBar and Belle measurements of the e+e-
to pi+pi-psi(2S) cross sections for center-of-mass energy between threshold and
5.5 GeV. The resonant parameters of the Y(4360) and Y(4660) are determined. The
mass is 4355^{+9}_{-10}\pm 9 MeV/c^2 and the width is 103^{+17}_{-15}\pm 11
MeV/c^2 for the Y(4360), and the mass is 4661^{+9}_{-8}\pm 6 MeV/c^2 and the
width is 42^{+17}_{-12}\pm 6 MeV/c^2 for the Y(4660). The production of the
Y(4260) in pi+pi-psi(2S) mode is found to be at 2\sigma level, and B(Y(4260) to
pi+pi-psi(2S))\Gamma_{e+e-} is found to be less than 4.3 eV/c^2 at the 90%
confidence level, or equal to 7.4^{+2.1}_{-1.7} eV/c^2 depending on it
interferes with the Y(4360) constructively or destructively. These information
will shed light on the understanding of the nature of the Y states observed in
initial state radiation processes.Comment: 8 pages, 4 figure
Constructing Breaker Sequence based System Restoration Strategy with Graph Theory
This paper has proposed a mapping approach to serve as an interface between the branch-bus model and the breaker-based model. In order to find the specific optimal operation for breakers in substations according to the restoration strategies, firstly, the paper has established the breaker-based model for the substation by using graphic theory, and then the optimal operation sequence for breakers has been figured out by adopting Dijkstra algorithm. Finally, a case study for a realistic power system has been analyzed to demonstrate the feasibility and efficiency of the approach.published_or_final_versio
Dynamic Coordinated Condition-Based Maintenance for Multiple Components With External Conditions
published_or_final_versio
Two-dimensional structures of ferroelectric domain inversion in LiNbO3 by direct electron beam lithography
We report on the fabrication of domain-reversed structures in LiNbO3 by means
of direct electron beam lithography at room temperature without any static
bias. The LiNbO3 crystals were chemically etched after the exposure of electron
beam and then, the patterns of domain inversion were characterized by atomic
force microscopy (AFM). In our experiment, an interesting phenomenon occurred
when the electron beam wrote a one-dimensional (1-D) grating on the negative
c-face: a two-dimensional (2-D) dotted array was observed on the positive c-
face, which is significant for its potential to produce 2-D and
three-dimensional photonic crystals. Furthermore, we also obtained 2-D
ferroelectric domain inversion in the whole LiNbO3 crystal by writing the 2-D
square pattern on the negative c-face. Such a structure may be utilized to
fabricate 2-D nonlinear photonic crystal. AFM demonstrates that a 2-D
domain-reversed structure has been achieved not only on the negative c-face of
the crystal, but also across the whole thickness of the crystal.Comment: 17 pages, 4 figure
Morphology and Orientation Selection of Non-Metallic Inclusions in Electrified Molten Metal
The effect of electric current on morphology and orientation selection of non-metallic inclusions in molten metal has been investigated using theoretical modelling and numerical calculation. Two geometric factors, namely the circularity (fc) and alignment ratio (fe) were introduced to describe the inclusions shape and configuration. Electric current free energy was calculated and the values were used to determine the thermodynamic preference between different microstructures. Electric current promotes the development of inclusion along the current direction by either expatiating directional growth or enhancing directional agglomeration. Reconfiguration of the inclusions to reduce the system electric resistance drives the phenomena. The morphology and orientation selection follows the routine to reduce electric free energy. The numerical results are in agreement with our experimental observations
Plaquette order and deconfined quantum critical point in the spin-1 bilinear-biquadratic Heisenberg model on the honeycomb lattice
We have precisely determined the ground state phase diagram of the quantum
spin-1 bilinear-biquadratic Heisenberg model on the honeycomb lattice using the
tensor renormalization group method. We find that the ferromagnetic,
ferroquadrupolar, and a large part of the antiferromagnetic phases are stable
against quantum fluctuations. However, around the phase where the ground state
is antiferroquadrupolar ordered in the classical limit, quantum fluctuations
suppress completely all magnetic orders, leading to a plaquette order phase
which breaks the lattice symmetry but preserves the spin SU(2) symmetry. On the
evidence of our numerical results, the quantum phase transition between the
antiferromagnetic phase and the plaquette phase is found to be either a direct
second order or a very weak first order transition.Comment: 6 pages, 9 figures, published versio
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