Hypersonic boundary layer transition induced by an isolated cylindrical roughness element is investigated using direct numerical simulation method based on a finite volume formulation.To simulate the transition proced...Hypersonic boundary layer transition induced by an isolated cylindrical roughness element is investigated using direct numerical simulation method based on a finite volume formulation.To simulate the transition procedure by resolving the generation and evolvement of small-scale coherent structures,and capture the shock wave at the same time,high-order minimum dispersion and controllable dissipation scheme is validated and then applied.The results are compared with the available measurements in the quiet wind tunnel,such as the dominated frequency and root mean square of pressure.The computational dominated frequency of 19.23 k Hz is very close to the experimental one,21 k Hz.Also,the disturbances of the roughness are mostly generated by the"jet"just before the roughness,and then they travel and develop downstream with the shear layer and vortex shedding.The transition is mainly dominated by the instabilities of both the horseshoe vortex and the shear layer.展开更多
Using colloidal particles with different thermosensitivities,we observe the transition from a crystalline solid to a dis-ordered glass by tuning the size mismatch of the constituent particles in quasi-two-dimensional c...Using colloidal particles with different thermosensitivities,we observe the transition from a crystalline solid to a dis-ordered glass by tuning the size mismatch of the constituent particles in quasi-two-dimensional configurations.The transition is clearly identifiable by the correlation functions of the orientational order parameters and its susceptibilities.Different from typical order-to-disorder transitions such as melting,where the underlying mechanism involves the diffusion of defects,the disordered phase in the crystal-to-glass transition grows via a nucleation process.The disordered clusters grow in size as the particle mismatch increases,and eventually percolate the whole system,which signifies the qualitative change from an ordered crystal to a disordered glass.展开更多
The interacting boson model for anomalous rotational bands is proposed. In the rotational SU(3) limit,an asymptotic limit is discussed. Within the framework of the model several analytic relations for energies and ele...The interacting boson model for anomalous rotational bands is proposed. In the rotational SU(3) limit,an asymptotic limit is discussed. Within the framework of the model several analytic relations for energies and electro-magnetic transition rates are derived.展开更多
The interacting boson model for anomalous rotational bands is proposed. In the rotational SU(3) limit,an asymptotic limit is discussed. Within the framework of the model several analytic relations for energies and ele...The interacting boson model for anomalous rotational bands is proposed. In the rotational SU(3) limit,an asymptotic limit is discussed. Within the framework of the model several analytic relations for energies and electro-magnetic transition rates are derived.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.11372159)
文摘Hypersonic boundary layer transition induced by an isolated cylindrical roughness element is investigated using direct numerical simulation method based on a finite volume formulation.To simulate the transition procedure by resolving the generation and evolvement of small-scale coherent structures,and capture the shock wave at the same time,high-order minimum dispersion and controllable dissipation scheme is validated and then applied.The results are compared with the available measurements in the quiet wind tunnel,such as the dominated frequency and root mean square of pressure.The computational dominated frequency of 19.23 k Hz is very close to the experimental one,21 k Hz.Also,the disturbances of the roughness are mostly generated by the"jet"just before the roughness,and then they travel and develop downstream with the shear layer and vortex shedding.The transition is mainly dominated by the instabilities of both the horseshoe vortex and the shear layer.
基金supported by the National Natural Science Foundation of China(11874395 and 12174434)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB3300000).|。
文摘Using colloidal particles with different thermosensitivities,we observe the transition from a crystalline solid to a dis-ordered glass by tuning the size mismatch of the constituent particles in quasi-two-dimensional configurations.The transition is clearly identifiable by the correlation functions of the orientational order parameters and its susceptibilities.Different from typical order-to-disorder transitions such as melting,where the underlying mechanism involves the diffusion of defects,the disordered phase in the crystal-to-glass transition grows via a nucleation process.The disordered clusters grow in size as the particle mismatch increases,and eventually percolate the whole system,which signifies the qualitative change from an ordered crystal to a disordered glass.
文摘The interacting boson model for anomalous rotational bands is proposed. In the rotational SU(3) limit,an asymptotic limit is discussed. Within the framework of the model several analytic relations for energies and electro-magnetic transition rates are derived.
文摘The interacting boson model for anomalous rotational bands is proposed. In the rotational SU(3) limit,an asymptotic limit is discussed. Within the framework of the model several analytic relations for energies and electro-magnetic transition rates are derived.
