Bom in a family whose last four generations shared master-mason tradition, architect used to be a natural career for Thomas Hardy. Although Hardy chose to devote to literature at last, he was never fully away from thi...Bom in a family whose last four generations shared master-mason tradition, architect used to be a natural career for Thomas Hardy. Although Hardy chose to devote to literature at last, he was never fully away from this field. The traces could be found in many of his literary works with many evidences, including his masterpiece, Tess of the d＇Urbervilles. This paper analyzes the meanings of the architectural elements employed in this novel, which are related to Hardy＇s own concern over church restoration movement in the Victorian Age, the arrangement of plot and the interaction with the characters.展开更多
Simulations of blood flows in arteries require numerical solutions of fluidstructure interactions involving Navier-Stokes equations coupled with large displacement visco-elasticity for the vessels.Among the various si...Simulations of blood flows in arteries require numerical solutions of fluidstructure interactions involving Navier-Stokes equations coupled with large displacement visco-elasticity for the vessels.Among the various simplifications which have been proposed, the surface pressure model leads to a hierarchy of simpler models including one that involves only the pressure. The model exhibits fundamental frequencies which can be computed and compared with the pulse. Yet unconditionally stable time discretizations can be constructed by combining implicit time schemes with Galerkin-characteristic discretization of the convection terms in the Navier-Stokes equations. Such problems with prescribed pressure on the walls will be shown to be efficient and accurate as an approximation of the full fluid structure interaction problem.展开更多
We report an experimental generation of polarization-entangled photon pairs in a cold atomic ensemble. A single Stokes photon and one spin-wave excitation are simultaneously created via spontaneous Raman scattering. T...We report an experimental generation of polarization-entangled photon pairs in a cold atomic ensemble. A single Stokes photon and one spin-wave excitation are simultaneously created via spontaneous Raman scattering. The spin-wave excitation is then converted into an anti-Stokes photon via an electromagnetic-induced-transparency reading process. The measured cross-correlation functions between the Stokes and anti-Stokes photons for two orthogonal polarizations are -75 and 74, respectively, at a generation rate of the photon pair of -60/s. Based on such correlations, we obtain polarization-entangled photon pairs, whose Bell parameter is S = 2.77 4- 0.01, violating Bell-CHSH inequality by -77 standard deviations. The presented polarization-entangled photon source has high entanglement degree and fast generation rate, which will promise us to apply it in future quantum repeater.展开更多
Terahertz(THz) generation by periodically-poled RbTiOPO_4(PPRTP) with a quasi-phase-matching scheme based on cascaded difference frequency generation(DFG) processes is theoretically analyzed. The cascaded Stokes and a...Terahertz(THz) generation by periodically-poled RbTiOPO_4(PPRTP) with a quasi-phase-matching scheme based on cascaded difference frequency generation(DFG) processes is theoretically analyzed. The cascaded Stokes and anti-Stokes interaction processes are investigated from coupled wave equations. The THz intensities and quantum conversion efficiency are calculated. Compared with that of non-cascaded DFG processes, the THz intensity in 7-order cascaded DFG processes is increased to 2.95 times. The quantum conversion efficiency of 149.9% in cascaded processes can be realized, which exceeds the Manley-Rowe limit.展开更多
文摘Bom in a family whose last four generations shared master-mason tradition, architect used to be a natural career for Thomas Hardy. Although Hardy chose to devote to literature at last, he was never fully away from this field. The traces could be found in many of his literary works with many evidences, including his masterpiece, Tess of the d＇Urbervilles. This paper analyzes the meanings of the architectural elements employed in this novel, which are related to Hardy＇s own concern over church restoration movement in the Victorian Age, the arrangement of plot and the interaction with the characters.
文摘Simulations of blood flows in arteries require numerical solutions of fluidstructure interactions involving Navier-Stokes equations coupled with large displacement visco-elasticity for the vessels.Among the various simplifications which have been proposed, the surface pressure model leads to a hierarchy of simpler models including one that involves only the pressure. The model exhibits fundamental frequencies which can be computed and compared with the pulse. Yet unconditionally stable time discretizations can be constructed by combining implicit time schemes with Galerkin-characteristic discretization of the convection terms in the Navier-Stokes equations. Such problems with prescribed pressure on the walls will be shown to be efficient and accurate as an approximation of the full fluid structure interaction problem.
基金the National Basic Research Program of China (2010CB923103)the National Natural Science Foundation of China (11475109, 11274211 and 60821004)
文摘We report an experimental generation of polarization-entangled photon pairs in a cold atomic ensemble. A single Stokes photon and one spin-wave excitation are simultaneously created via spontaneous Raman scattering. The spin-wave excitation is then converted into an anti-Stokes photon via an electromagnetic-induced-transparency reading process. The measured cross-correlation functions between the Stokes and anti-Stokes photons for two orthogonal polarizations are -75 and 74, respectively, at a generation rate of the photon pair of -60/s. Based on such correlations, we obtain polarization-entangled photon pairs, whose Bell parameter is S = 2.77 4- 0.01, violating Bell-CHSH inequality by -77 standard deviations. The presented polarization-entangled photon source has high entanglement degree and fast generation rate, which will promise us to apply it in future quantum repeater.
基金supported by the National Natural Science Foundation of China(Nos.61201101,61601183 and 61205003)the Young Backbone Teachers in University of Henan Province(No.2014GGJS-065)+1 种基金the Foundation and Advanced Technology Research Program of Henan Province(No.162300410269)the Program for Innovative Research Team(in Science and Technology)in University of Henan Province(No.16IRTSTHN017)
文摘Terahertz(THz) generation by periodically-poled RbTiOPO_4(PPRTP) with a quasi-phase-matching scheme based on cascaded difference frequency generation(DFG) processes is theoretically analyzed. The cascaded Stokes and anti-Stokes interaction processes are investigated from coupled wave equations. The THz intensities and quantum conversion efficiency are calculated. Compared with that of non-cascaded DFG processes, the THz intensity in 7-order cascaded DFG processes is increased to 2.95 times. The quantum conversion efficiency of 149.9% in cascaded processes can be realized, which exceeds the Manley-Rowe limit.
