We consider the local unitary equivalence of a class of quantum states in a bipartite case and a multipartite case. The necessary and sufficient condition is presented. As special cases, the local unitary equivalent c...We consider the local unitary equivalence of a class of quantum states in a bipartite case and a multipartite case. The necessary and sufficient condition is presented. As special cases, the local unitary equivalent classes of isotropic state and Werner state are provided. Then we study the local unitary similar equivalence of this class of quantum states and analyze the necessary and sufficient condition.展开更多
Current developments on fatigue life prediction methods have been systematically reviewed.In con- sideration of the irreversibility of energy dissipation during fatigue damage process,the main contents for fatigue dam...Current developments on fatigue life prediction methods have been systematically reviewed.In con- sideration of the irreversibility of energy dissipation during fatigue damage process,the main contents for fatigue damage estimation and localized equivalence as well as simulation models have been established.A frame of energy-based fatigue life prediction method has been proposed,meanwhile, the procedure in application to a practical structure component has been described.展开更多
The first part of this paper gives a complete description of local automorphism groups for Levi degenerate hypersurfaces of finite type in C2. It is also proved that, with the exception of hypersurfaces of the form v ...The first part of this paper gives a complete description of local automorphism groups for Levi degenerate hypersurfaces of finite type in C2. It is also proved that, with the exception of hypersurfaces of the form v = |z|k, local automorphisms are always determined by their 1-jets. Using this result, the second part describes special normal forms which by an additional normalization eliminate the nonlinear symmetries of the model and allows to decide effectively about local equivalence of two hypersurfaces given in this normal form.展开更多
Numerical simulations were performed to model the non-reacting and reacting flow behind a rearward step flameholder in Mach 1.6 supersonic flow with fuel injection at the step base.The combustor geometry was based on ...Numerical simulations were performed to model the non-reacting and reacting flow behind a rearward step flameholder in Mach 1.6 supersonic flow with fuel injection at the step base.The combustor geometry was based on the University of Florida scramjet experimental facility.Turbulence was modeled using k-u shear stress transport(SST),laminar flamelet was used for combustion modeling.Wall static pressure showed good agreement with experimental data for non-reacting and reacting flow.For non-reacting flow,dummy fuel helium mole fraction distribution in the recirculation region behind the step was validated with planar laser induced fluorescence(PLIF)images in experiments.To improve the combustion characteristics,air was injected in tandem with hydrogen at step base using various configurations.With all fuel injection as baseline,the case with 2 air jets around each fuel jet and air injected at 2 times the stagnation pressure of fuel showed the most improvement compared to other cases.It was most effective in reducing the local fuel richness,shortening the flame length and increasing combustion efficiency.展开更多
The experiment was carried out in homogeneous propane-air mixture and in several concentration gradient of mixture. Igniter is put on the upper side of the combustion chamber In concentration gradient experiment, fixt...The experiment was carried out in homogeneous propane-air mixture and in several concentration gradient of mixture. Igniter is put on the upper side of the combustion chamber In concentration gradient experiment, fixture was ignited from lean side. An experimental study was conducted in a combustion chamber. The combustion chamber has glass windows for optical measurements at any side. For the measurement of distribution of fuel concentration, infrared absorption method using 3.39μm He-Ne laser was used, and for the observation of propagating flame, Schlieren method was employed. As a measurement result of flame propagation velocity and flammable limit, for a mixture of an identical local equivalence ratio, flame propagation velocity in concentration gradient is faster than that in homogeneous mixture, and rich flammable limit in concentration gradient shows a tendency to be higher than that in homogeneous mixture.展开更多
In this paper, a theorem of the local qualitative classification of equllibrium of a special type of higher order ordinary differential system is provided for establishing the theoretical bases to extend the planer. ...In this paper, a theorem of the local qualitative classification of equllibrium of a special type of higher order ordinary differential system is provided for establishing the theoretical bases to extend the planer. qualitative nomgraphy in [1] to the special geometricaljy qualitative method in 3-dimensions.展开更多
The construction of multipartite unextendible product bases(UPBs)is a basic problem in quantum information.We respectively construct two families of 2×2×4 and 2×2×2×4 UPBs of size eight by usi...The construction of multipartite unextendible product bases(UPBs)is a basic problem in quantum information.We respectively construct two families of 2×2×4 and 2×2×2×4 UPBs of size eight by using the existing four-qubit and five-qubit UPBs.As an application,we construct novel families of multipartite positive-partial-transpose entangled states,as well as their entanglement properties in terms of the geometric measure of entanglement.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.1140103261473325+9 种基金115011531110522611275131and 11401106)the Fundamental Research Funds for the Central UniversitiesChina(Grant Nos.15CX08011A and 24720122013)the Natural Science Foundation of Hainan ProvinceChina(Grant Nos.20151005 and 20151010)the Scientific Research Foundation for the Returned Overseas Chinese ScholarsState Education Ministry
文摘We consider the local unitary equivalence of a class of quantum states in a bipartite case and a multipartite case. The necessary and sufficient condition is presented. As special cases, the local unitary equivalent classes of isotropic state and Werner state are provided. Then we study the local unitary similar equivalence of this class of quantum states and analyze the necessary and sufficient condition.
文摘Current developments on fatigue life prediction methods have been systematically reviewed.In con- sideration of the irreversibility of energy dissipation during fatigue damage process,the main contents for fatigue damage estimation and localized equivalence as well as simulation models have been established.A frame of energy-based fatigue life prediction method has been proposed,meanwhile, the procedure in application to a practical structure component has been described.
文摘The first part of this paper gives a complete description of local automorphism groups for Levi degenerate hypersurfaces of finite type in C2. It is also proved that, with the exception of hypersurfaces of the form v = |z|k, local automorphisms are always determined by their 1-jets. Using this result, the second part describes special normal forms which by an additional normalization eliminate the nonlinear symmetries of the model and allows to decide effectively about local equivalence of two hypersurfaces given in this normal form.
文摘Numerical simulations were performed to model the non-reacting and reacting flow behind a rearward step flameholder in Mach 1.6 supersonic flow with fuel injection at the step base.The combustor geometry was based on the University of Florida scramjet experimental facility.Turbulence was modeled using k-u shear stress transport(SST),laminar flamelet was used for combustion modeling.Wall static pressure showed good agreement with experimental data for non-reacting and reacting flow.For non-reacting flow,dummy fuel helium mole fraction distribution in the recirculation region behind the step was validated with planar laser induced fluorescence(PLIF)images in experiments.To improve the combustion characteristics,air was injected in tandem with hydrogen at step base using various configurations.With all fuel injection as baseline,the case with 2 air jets around each fuel jet and air injected at 2 times the stagnation pressure of fuel showed the most improvement compared to other cases.It was most effective in reducing the local fuel richness,shortening the flame length and increasing combustion efficiency.
文摘The experiment was carried out in homogeneous propane-air mixture and in several concentration gradient of mixture. Igniter is put on the upper side of the combustion chamber In concentration gradient experiment, fixture was ignited from lean side. An experimental study was conducted in a combustion chamber. The combustion chamber has glass windows for optical measurements at any side. For the measurement of distribution of fuel concentration, infrared absorption method using 3.39μm He-Ne laser was used, and for the observation of propagating flame, Schlieren method was employed. As a measurement result of flame propagation velocity and flammable limit, for a mixture of an identical local equivalence ratio, flame propagation velocity in concentration gradient is faster than that in homogeneous mixture, and rich flammable limit in concentration gradient shows a tendency to be higher than that in homogeneous mixture.
文摘In this paper, a theorem of the local qualitative classification of equllibrium of a special type of higher order ordinary differential system is provided for establishing the theoretical bases to extend the planer. qualitative nomgraphy in [1] to the special geometricaljy qualitative method in 3-dimensions.
基金LC was supported by the NNSF of China(Grant No.11871089)the Fundamental Research Funds for the Central Universities(Grant Nos.KG12040501,ZG216S1810 and ZG226S18C1).
文摘The construction of multipartite unextendible product bases(UPBs)is a basic problem in quantum information.We respectively construct two families of 2×2×4 and 2×2×2×4 UPBs of size eight by using the existing four-qubit and five-qubit UPBs.As an application,we construct novel families of multipartite positive-partial-transpose entangled states,as well as their entanglement properties in terms of the geometric measure of entanglement.