The transverse momentum spectra of different types of particles produced in central and peripheral gold–gold(Au–Au)and inelastic proton–proton(pp)collisions at the Relativistic Heavy Ion Collider,as well as in cent...The transverse momentum spectra of different types of particles produced in central and peripheral gold–gold(Au–Au)and inelastic proton–proton(pp)collisions at the Relativistic Heavy Ion Collider,as well as in central and peripheral lead-lead(Pb–Pb)and pp collisions at the Large Hadron Collider,are analyzed by the multi-component standard(Boltzmann–Gibbs,Fermi–Dirac,and Bose–Einstein)distributions.The obtained results from the standard distribution give an approximate agreement with the measured experimental data by the STAR,PHENIX,and ALICE Collaborations.The behavior of the effective(kinetic freeze-out)temperature,transverse flow velocity,and kinetic freeze-out volume for particles with different masses is obtained,which observes the early kinetic freezeout of heavier particles as compared to the lighter particles.The parameters of emissions of different particles are observed to be different,which reveals a direct signature of the mass-dependent differential kinetic freeze-out.It is also observed that the peripheral nucleus–nucleus(AA)and pp collisions at the same center-of-mass energy per nucleon pair are in good agreement in terms of the extracted parameters.展开更多
A new method for constructing the symmetric form for the hyperbolic systems is introduced. Then a new symmetric form of the equations of MHD transverse flow is constructed by adding an additional equation. With this n...A new method for constructing the symmetric form for the hyperbolic systems is introduced. Then a new symmetric form of the equations of MHD transverse flow is constructed by adding an additional equation. With this new form, we obtain the local existence of smooth solution including the case that the initial density may tend to the vacuum state at infinity. Furthermore, the uniformly a priori estimation for the classical solutions is established and the global smooth solutions for a kind of initial data are obtained.展开更多
By means of ink trace visualization of the flows in conventional straight, positively curved and negatively curved cascades with tip clearance, and measurement of the aerodynamic parameters in transverse section, and...By means of ink trace visualization of the flows in conventional straight, positively curved and negatively curved cascades with tip clearance, and measurement of the aerodynamic parameters in transverse section, and by appling topology theory, the topological structures and vortex structure in the transverse section of a blade cascade were analyzed. Compared with conventional straight cascade, blade positive curving eliminates the separation line of the upper passage vortex, and leads the secondary vortex to change from close separation to open separation, while blade negative curving effects merely the positions of singular points and the intensities and scales of vortex.展开更多
The property of fluid field of one-dimensional magnetohydrodynamics (MHD) transverse flow after the appearance of singularity is discussed. By the method of iteration, the strong discontinuity (shock wave) and entropy...The property of fluid field of one-dimensional magnetohydrodynamics (MHD) transverse flow after the appearance of singularity is discussed. By the method of iteration, the strong discontinuity (shock wave) and entropy solution are constructed and the estimations on the singularity of the solution near the point of blow-up are obtained.展开更多
This paper studies the unsteady heat and mass natural convection in a highly porous medium bounded by an infinite vertical porous wall. The unsteady source of the problem arises from the transverse oscillations in suc...This paper studies the unsteady heat and mass natural convection in a highly porous medium bounded by an infinite vertical porous wall. The unsteady source of the problem arises from the transverse oscillations in suction velocity of fluids, The analytical results for the problem are obtained based on the method of small parameter, and show that the natural circulation in the porous medium is affected by this kind of oscillation.展开更多
Width spread is usually considered in hot rolling, nevertheless, it can be ignore in cold rolling. In order to control the crown and flatness better simultaneously and realize the decoupling of crown and flatness, the...Width spread is usually considered in hot rolling, nevertheless, it can be ignore in cold rolling. In order to control the crown and flatness better simultaneously and realize the decoupling of crown and flatness, the transverse displacement function of strip is defined and deduced. The factors that affects the width spread are analyzing with the function. According to the unchanged principle of volume before and after rolling, the flatness model which considers the width spread is deduced. Through the model, the transverse metal flowing of different stands and different thickness is analyzing, it is found that the width spread is biggest in cold rolling at the No. 1 stand because of the maximum thickness and reduction and the minimum deformation resistance. It gives a good foundation for the decoupling of crown and flatness.展开更多
The centrality dependence of transverse momentum spectra for identified hadrons at midrapidityin Au+Au collisions at √sNN=200GeV is systematically studied in a quark combination model. The PTspectra of π^±, K^...The centrality dependence of transverse momentum spectra for identified hadrons at midrapidityin Au+Au collisions at √sNN=200GeV is systematically studied in a quark combination model. The PTspectra of π^±, K^±, p(p) and A(A) in different centrality bins and the nuclear modification factors (Rcp) forthese hadrons are calculated. The centrality dependence of the average collective transverse velocity (β (r)) for the hot and dense quark matter is obtained in Au+Au collisions, and it is applied to a relative smallerCu+Cu collision system. The centrality dependence of PT spectra and the Rcp for π^0, Ks^0 and A in Cu-bCucollisions at √sNN = 200 GeV are well described. The results show that (β (r)〉is only a function of the numberof participants Npart and it is independent of the collision system.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11575103 and 11947418)the Chinese Government Scholarship(China Scholarship Council)+2 种基金the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(STIP)(No.201802017)the Shanxi Provincial Natural Science Foundation(No.201901D111043)the Fund for Shanxi‘‘1331 Project’’Key Subjects Construction。
文摘The transverse momentum spectra of different types of particles produced in central and peripheral gold–gold(Au–Au)and inelastic proton–proton(pp)collisions at the Relativistic Heavy Ion Collider,as well as in central and peripheral lead-lead(Pb–Pb)and pp collisions at the Large Hadron Collider,are analyzed by the multi-component standard(Boltzmann–Gibbs,Fermi–Dirac,and Bose–Einstein)distributions.The obtained results from the standard distribution give an approximate agreement with the measured experimental data by the STAR,PHENIX,and ALICE Collaborations.The behavior of the effective(kinetic freeze-out)temperature,transverse flow velocity,and kinetic freeze-out volume for particles with different masses is obtained,which observes the early kinetic freezeout of heavier particles as compared to the lighter particles.The parameters of emissions of different particles are observed to be different,which reveals a direct signature of the mass-dependent differential kinetic freeze-out.It is also observed that the peripheral nucleus–nucleus(AA)and pp collisions at the same center-of-mass energy per nucleon pair are in good agreement in terms of the extracted parameters.
文摘A new method for constructing the symmetric form for the hyperbolic systems is introduced. Then a new symmetric form of the equations of MHD transverse flow is constructed by adding an additional equation. With this new form, we obtain the local existence of smooth solution including the case that the initial density may tend to the vacuum state at infinity. Furthermore, the uniformly a priori estimation for the classical solutions is established and the global smooth solutions for a kind of initial data are obtained.
文摘By means of ink trace visualization of the flows in conventional straight, positively curved and negatively curved cascades with tip clearance, and measurement of the aerodynamic parameters in transverse section, and by appling topology theory, the topological structures and vortex structure in the transverse section of a blade cascade were analyzed. Compared with conventional straight cascade, blade positive curving eliminates the separation line of the upper passage vortex, and leads the secondary vortex to change from close separation to open separation, while blade negative curving effects merely the positions of singular points and the intensities and scales of vortex.
文摘The property of fluid field of one-dimensional magnetohydrodynamics (MHD) transverse flow after the appearance of singularity is discussed. By the method of iteration, the strong discontinuity (shock wave) and entropy solution are constructed and the estimations on the singularity of the solution near the point of blow-up are obtained.
文摘This paper studies the unsteady heat and mass natural convection in a highly porous medium bounded by an infinite vertical porous wall. The unsteady source of the problem arises from the transverse oscillations in suction velocity of fluids, The analytical results for the problem are obtained based on the method of small parameter, and show that the natural circulation in the porous medium is affected by this kind of oscillation.
基金Supported by Beijing Higher Education Young Elite Teacher Project(No.YETP0369)
文摘Width spread is usually considered in hot rolling, nevertheless, it can be ignore in cold rolling. In order to control the crown and flatness better simultaneously and realize the decoupling of crown and flatness, the transverse displacement function of strip is defined and deduced. The factors that affects the width spread are analyzing with the function. According to the unchanged principle of volume before and after rolling, the flatness model which considers the width spread is deduced. Through the model, the transverse metal flowing of different stands and different thickness is analyzing, it is found that the width spread is biggest in cold rolling at the No. 1 stand because of the maximum thickness and reduction and the minimum deformation resistance. It gives a good foundation for the decoupling of crown and flatness.
基金Supported by National Natural Science Foundation of China (10775089, 10475049)Science Fund of Qufu Normal University
文摘The centrality dependence of transverse momentum spectra for identified hadrons at midrapidityin Au+Au collisions at √sNN=200GeV is systematically studied in a quark combination model. The PTspectra of π^±, K^±, p(p) and A(A) in different centrality bins and the nuclear modification factors (Rcp) forthese hadrons are calculated. The centrality dependence of the average collective transverse velocity (β (r)) for the hot and dense quark matter is obtained in Au+Au collisions, and it is applied to a relative smallerCu+Cu collision system. The centrality dependence of PT spectra and the Rcp for π^0, Ks^0 and A in Cu-bCucollisions at √sNN = 200 GeV are well described. The results show that (β (r)〉is only a function of the numberof participants Npart and it is independent of the collision system.