In this paper, the outline of the Mach 4 supersonic wind tunnel for the investigation of the supersonic internal flows in ducts was firstly described. Secondly, the location, structure and characteristics of the Mach ...In this paper, the outline of the Mach 4 supersonic wind tunnel for the investigation of the supersonic internal flows in ducts was firstly described. Secondly, the location, structure and characteristics of the Mach 2 and Mach 4 pseudo-shock waves in a square duct were investigated by color schlieren photographs and duct wall pressure fluctuation measurements. Finally, the wall shear stress distributions on the side, top and bottom walls of the square duct with the Mach 4 pseudo-shock wave were investigated qualitatively by the shear stress-sensitive liquid crystal visualization method. The side wall boundary layer separation region under the first shock is narrow near the top wall, while the side wall boundary layer separation region under the first shock is very wide near the bottom wall.展开更多
The simplest spin-orbital model can host a nematic spin-orbital liquid state on the triangular lattice.We provide clear evidence that the ground state of the SU(4)Kugel-Khomskii model on the triangular lattice can be ...The simplest spin-orbital model can host a nematic spin-orbital liquid state on the triangular lattice.We provide clear evidence that the ground state of the SU(4)Kugel-Khomskii model on the triangular lattice can be well described by a‘‘single”Gutzwiller projected wave function with an emergent parton Fermi surface,despite it exhibits strong finite-size effect in quasi-one-dimensional cylinders.The finite-size effect can be resolved by the fact that the parton Fermi surface consists of open orbits in the reciprocal space.Thereby,a stripy liquid state is expected in the two-dimensional limit,which preserves the SU(4)symmetry while breaks the translational symmetry by doubling the unit cell along one of the lattice vector directions.It is indicative that these stripes are critical and the central charge is c=3,in agreement with the SU(4)1Wess-Zumino-Witten conformal field theory.All these results are consistent with the Lieb-Schultz-Mattis-Oshikawa-Hastings theorem.展开更多
文摘In this paper, the outline of the Mach 4 supersonic wind tunnel for the investigation of the supersonic internal flows in ducts was firstly described. Secondly, the location, structure and characteristics of the Mach 2 and Mach 4 pseudo-shock waves in a square duct were investigated by color schlieren photographs and duct wall pressure fluctuation measurements. Finally, the wall shear stress distributions on the side, top and bottom walls of the square duct with the Mach 4 pseudo-shock wave were investigated qualitatively by the shear stress-sensitive liquid crystal visualization method. The side wall boundary layer separation region under the first shock is narrow near the top wall, while the side wall boundary layer separation region under the first shock is very wide near the bottom wall.
基金supported by the National Natural Science Foundation of China(12034004 and 11774306)the K.C.Wong Education Foundation(GJTD2020–01)+3 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDB28000000)funded by the European Research Council(ERC)under the European Unions Horizon 2020 Research and Innovation Program(771537)supported by the Deutsche Forschungsgemeinschaft through project A06 of SFB 1143(247310070)The numerical simulations in this work are based on the GraceQ project(www.gracequantum.org)。
文摘The simplest spin-orbital model can host a nematic spin-orbital liquid state on the triangular lattice.We provide clear evidence that the ground state of the SU(4)Kugel-Khomskii model on the triangular lattice can be well described by a‘‘single”Gutzwiller projected wave function with an emergent parton Fermi surface,despite it exhibits strong finite-size effect in quasi-one-dimensional cylinders.The finite-size effect can be resolved by the fact that the parton Fermi surface consists of open orbits in the reciprocal space.Thereby,a stripy liquid state is expected in the two-dimensional limit,which preserves the SU(4)symmetry while breaks the translational symmetry by doubling the unit cell along one of the lattice vector directions.It is indicative that these stripes are critical and the central charge is c=3,in agreement with the SU(4)1Wess-Zumino-Witten conformal field theory.All these results are consistent with the Lieb-Schultz-Mattis-Oshikawa-Hastings theorem.
