141,678 research outputs found
Optimal transfer of an unknown state via a bipartite operation
A fundamental task in quantum information science is to transfer an unknown
state from particle to particle (often in remote space locations) by
using a bipartite quantum operation . We suggest the power of
for quantum state transfer (QST) to be the maximal average
probability of QST over the initial states of particle and the
identifications of the state vectors between and . We find the QST power
of a bipartite quantum operations satisfies four desired properties between two
-dimensional Hilbert spaces. When and are qubits, the analytical
expressions of the QST power is given. In particular, we obtain the exact
results of the QST power for a general two-qubit unitary transformation.Comment: 6 pages, 1 figur
Effect of iron on the microstructure and mechanical property of Al-Mg-Si-Mn and Al-Mg-Si diecast alloys
This article is made available through the Brunel Open Access Publishing Fund. Copyright @ 2012 Elsevier B.V.This article has been made available through the Brunel Open Access Publishing Fund.AlāMgāSi based alloys can provide super ductility to satisfy the demands of thin wall castings in the application of automotive structure. In this work, the effect of iron on the microstructure and mechanical properties of the AlāMgāSi diecast alloys with different Mn concentrations is investigated. The CALPHAD (acronym of Calculation of Phase Diagrams) modelling with the thermodynamic properties of the multi-component AlāMgāSiāMnāFe and AlāMgāSiāFe systems is carried out to understand the role of alloying on the formation of different primary Fe-rich intermetallic compounds. The results showed that the Fe-rich intermetallic phases precipitate in two solidification stages in the high pressure die casting process: one is in the shot sleeve and the other is in the die cavity, resulting in the different morphologies and sizes. In the AlāMgāSiāMn alloys, the Fe-rich intermetallic phase formed in the shot sleeve exhibited coarse compact morphology and those formed in the die cavity were fine compact particles. Although with different morphologies, the compact intermetallics were identified as the same Ī±-AlFeMnSi phase with typical composition of Al24(Fe,Mn)6Si2. With increased Fe content, Ī²-AlFe was found in the microstructure with a long needle-shaped morphology, which was identified as Al13(Fe,Mn)4Si0.25. In the AlāMgāSi alloy, the identified Fe-rich intermetallics included the compact Ī±-AlFeSi phase with typical composition of Al8Fe2Si and the needle-shaped Ī²-AlFe phase with typical composition of Al13Fe4. Generally, the existence of iron in the alloy slightly increases the yield strength, but significantly reduces the elongation. The ultimate tensile strength maintains at similar levels when Fe contents is less than 0.5 wt%, but decreases significantly with the further increased Fe concentration in the alloys. CALPHAD modelling shows that the addition of Mn enlarges the Fe tolerance for the formation of Ī±-AlFeMnSi intermetallics and suppresses the formation of Ī²-AlFe phase in the AlāMgāSi alloys, and thus improves their mechanical properties.EPSRC and JL
Effect of iron on the microstructure and mechanical property of Al-Mg-Si-Mn and Al-Mg-Si diecast alloys
This article is made available through the Brunel Open Access Publishing Fund. Copyright @ 2012 Elsevier B.V.This article has been made available through the Brunel Open Access Publishing Fund.AlāMgāSi based alloys can provide super ductility to satisfy the demands of thin wall castings in the application of automotive structure. In this work, the effect of iron on the microstructure and mechanical properties of the AlāMgāSi diecast alloys with different Mn concentrations is investigated. The CALPHAD (acronym of Calculation of Phase Diagrams) modelling with the thermodynamic properties of the multi-component AlāMgāSiāMnāFe and AlāMgāSiāFe systems is carried out to understand the role of alloying on the formation of different primary Fe-rich intermetallic compounds. The results showed that the Fe-rich intermetallic phases precipitate in two solidification stages in the high pressure die casting process: one is in the shot sleeve and the other is in the die cavity, resulting in the different morphologies and sizes. In the AlāMgāSiāMn alloys, the Fe-rich intermetallic phase formed in the shot sleeve exhibited coarse compact morphology and those formed in the die cavity were fine compact particles. Although with different morphologies, the compact intermetallics were identified as the same Ī±-AlFeMnSi phase with typical composition of Al24(Fe,Mn)6Si2. With increased Fe content, Ī²-AlFe was found in the microstructure with a long needle-shaped morphology, which was identified as Al13(Fe,Mn)4Si0.25. In the AlāMgāSi alloy, the identified Fe-rich intermetallics included the compact Ī±-AlFeSi phase with typical composition of Al8Fe2Si and the needle-shaped Ī²-AlFe phase with typical composition of Al13Fe4. Generally, the existence of iron in the alloy slightly increases the yield strength, but significantly reduces the elongation. The ultimate tensile strength maintains at similar levels when Fe contents is less than 0.5 wt%, but decreases significantly with the further increased Fe concentration in the alloys. CALPHAD modelling shows that the addition of Mn enlarges the Fe tolerance for the formation of Ī±-AlFeMnSi intermetallics and suppresses the formation of Ī²-AlFe phase in the AlāMgāSi alloys, and thus improves their mechanical properties.EPSRC and JL
Determinant representations of scalar products for the open XXZ chain with non-diagonal boundary terms
With the help of the F-basis provided by the Drinfeld twist or factorizing
F-matrix for the open XXZ spin chain with non-diagonal boundary terms, we
obtain the determinant representations of the scalar products of Bethe states
of the model.Comment: Latex file, 28 pages, based on the talk given by W. -L. Yang at
Statphys 24, Cairns, Australia, 19-23 July, 201
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