Possibility of kaon-condensed phase in hyperon-mixed matter is considered as high-density multistrangeness system,which may be realized in neutron stars.The interaction model is based on chiral symmetry for kaon-baryo...Possibility of kaon-condensed phase in hyperon-mixed matter is considered as high-density multistrangeness system,which may be realized in neutron stars.The interaction model is based on chiral symmetry for kaon-baryon and kaon-kaon interactions,being combined with the relativistic mean-field theory for two-body baryonbaryon(B-B)interaction.In addition,the Lorentz invariant forms of many-baryon repulsive force(MBR)and threenucleon attractive force(TNA)are phenomenologically introduced,where unknown parameters are fixed to satisfy the saturation properties of symmetric nuclear matter and the causality condition that the sound velocity should be less than the speed of light.It is shown that the equation of state with kaon condensation in hyperon-mixed matter is stiff enough to be consistent with recent observations of massive neutron stars.展开更多
A cell model to describe and optimize heat and mass transfer in contact heat exchangers for utilization of exhaust gases heat is proposed. The model is based on the theory of Markov chains and allows calculating heat ...A cell model to describe and optimize heat and mass transfer in contact heat exchangers for utilization of exhaust gases heat is proposed. The model is based on the theory of Markov chains and allows calculating heat and mass transfer at local moving force of the processes in each cell. The total process is presented as two parallel chains of cells (one for water flow and one for gas flow). The corresponding cells of the chains can exchange heat and mass, and water and gas can travel along their chains according to their transition ma-trices. The results of numerical experiments showed that the most part of heat transfer occurs due to moisture condensation from gas and the most intense heat transfer goes near the inlet of gas. Experimental validation of the model showed a good correlation between calculated and experimental data for an industrial contact heat exchanger if appropriate empirical equations were used to calculate heat and mass transfer coefficient. It was also shown that there exists the optimum height of heat exchanger that gave the maximum gain in heat energy utilization.展开更多
By using the new experimental data of AA potential, this paper has performed a full calculation for strange hadronic matter with different strangeness contents as well as its consequences on the global properties of n...By using the new experimental data of AA potential, this paper has performed a full calculation for strange hadronic matter with different strangeness contents as well as its consequences on the global properties of neutron star matter in relativistic mean field model. It finds that the new weak hyperon-hyperon interaction makes the equations of state much stiffer than the result of the previous strong hyperon hyperon interaction, and even stiffer than the result without consideration of hyperon-hyperon interaction. This new hyperon-hyperon interaction results in a maximum mass of 1.75M⊙ （where M⊙ stands for the mass of the Sun）, about 0.2-0.5M⊙ larger than the previous prediction with the presence of hyperons. After examining carefully the onset densities of kaon condensation it finds that this new weak version of hyperon-hyperon interaction favours the occurrence of kaons in comparison with the strong one.展开更多
Indirect evaporative cooling(IEC)is a kind of high efficiency,energy-saving and environmental protection cooling technology,which has been widely used in data centers and other fields in recent years.In this paper,the...Indirect evaporative cooling(IEC)is a kind of high efficiency,energy-saving and environmental protection cooling technology,which has been widely used in data centers and other fields in recent years.In this paper,the optimized two-dimensional non-condensation state model of indirect evaporative cooling was proposed.Meanwhile the computer program was updated to solve the developed mathematical model under variable fresh air conditions.The optimized model was verified by the experimental data,and the maximum deviation was only 4.6%.Based on the modified model and the annual hourly meteorological parameters in Tianjin,China,it was analyzed the optimal heat transfer area of IEC used as fresh air pre-cooling unit under various air volumes to provide references for system design and equipment selection.Finally,taking an IEC-primary return air conditioning system of a gymnasium as an example,the hourly energy-saving effect of whole year was simulated by the developed IEC model.The simulation results showed that IEC could control the fresh air temperature below 27℃ and the moisture content below 18 g/kg throughout the year,and undertook 102.6% of the total fresh air cooling load.The findings are useful in future system optimization and design of IEC equipment.展开更多
We investigate the ground-state properties and the dynamics of quasi-one-dimensional quantum droplets of binary Bose condensates by employing the Gaussian state theory.We show that there exists three quantum phases fo...We investigate the ground-state properties and the dynamics of quasi-one-dimensional quantum droplets of binary Bose condensates by employing the Gaussian state theory.We show that there exists three quantum phases for the ground states of the droplets,including a coherent state and two macroscopic squeezed states.The phase transition between two macroscopic squeezed states is of the third order;while between the macroscopic squeezed state and the coherent is of a crossover type.As for the dynamics,we find that,by tuning the reduced scattering length to a negative value,a significant fraction of the atoms can be transferred from a coherent state to a macroscopic squeezed state.Our studies open up the possibility of generating macroscopic squeezed states using binary condensates.展开更多
The geometrical dimensions of the rough structures as well as the non-condensable gases in the vapor mixture can have the great effect on the nucleation position and the wetting state of the droplet,which further infl...The geometrical dimensions of the rough structures as well as the non-condensable gases in the vapor mixture can have the great effect on the nucleation position and the wetting state of the droplet,which further influence the condensation heat flux.In this paper,the multispecies multiphase lattice Boltzmann method together with a thermal phase change model is used to investigate the dropwise condensation on a rough surface enhanced with pillars.The effect of the geometric dimensions including pillar height H,pillar width W and pillar space S is investigated.Then the effect of non-condensable gases on the contact angle of a droplet on textured surface is studied.The results show that the local heat flux and the wetting area are higher while the waiting time is shorter at larger S,W and smaller H on the rough surface.The nucleation position rises from the bottom of grooves to the top with the increase of pillar height and the decrease of pillar space.The contact angle is larger and it is easier to maintain the Cassie state for droplet.When there exists non-condensable gas,the non-condensable gas obviously enhances the hydrophobicity of the rough surfaces compared with pure vapor.展开更多
In this paper we propose a uniformly convergent numerical method for discretizing singularly perturbed nonlinear eigenvalue problems under constraints with applications in Bose-Einstein condensation and quantum chemis...In this paper we propose a uniformly convergent numerical method for discretizing singularly perturbed nonlinear eigenvalue problems under constraints with applications in Bose-Einstein condensation and quantum chemistry.We begin with the time-independent Gross-Pitaevskii equation and show how to reformulate it into a singularly perturbed nonlinear eigenvalue problem under a constraint.Matched asymptotic approximations for the problem are presented to locate the positions and characterize the widths of boundary layers and/or interior layers in the solution.A uniformly convergent numerical method is proposed by using the normalized gradient flow and piecewise uniform mesh techniques based on the asymptotic approximations for the problem.Extensive numerical results are reported to demonstrate the effectiveness of our numerical method for the problems.Finally,the method is applied to compute ground and excited states of Bose-Einstein condensation in the semiclassical regime and some conclusive findings are reported.展开更多
文摘Possibility of kaon-condensed phase in hyperon-mixed matter is considered as high-density multistrangeness system,which may be realized in neutron stars.The interaction model is based on chiral symmetry for kaon-baryon and kaon-kaon interactions,being combined with the relativistic mean-field theory for two-body baryonbaryon(B-B)interaction.In addition,the Lorentz invariant forms of many-baryon repulsive force(MBR)and threenucleon attractive force(TNA)are phenomenologically introduced,where unknown parameters are fixed to satisfy the saturation properties of symmetric nuclear matter and the causality condition that the sound velocity should be less than the speed of light.It is shown that the equation of state with kaon condensation in hyperon-mixed matter is stiff enough to be consistent with recent observations of massive neutron stars.
文摘A cell model to describe and optimize heat and mass transfer in contact heat exchangers for utilization of exhaust gases heat is proposed. The model is based on the theory of Markov chains and allows calculating heat and mass transfer at local moving force of the processes in each cell. The total process is presented as two parallel chains of cells (one for water flow and one for gas flow). The corresponding cells of the chains can exchange heat and mass, and water and gas can travel along their chains according to their transition ma-trices. The results of numerical experiments showed that the most part of heat transfer occurs due to moisture condensation from gas and the most intense heat transfer goes near the inlet of gas. Experimental validation of the model showed a good correlation between calculated and experimental data for an industrial contact heat exchanger if appropriate empirical equations were used to calculate heat and mass transfer coefficient. It was also shown that there exists the optimum height of heat exchanger that gave the maximum gain in heat energy utilization.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10575119 and 10235030）, the Knowledge Innovation Project （Grant No KJCX2-SW-N02） of Chinese Academy of Sciences, the Major State Basic Research Development Program of China （Grant No G2000077400）, the Major Prophase Research Project of Fundamental Research of the Ministry of Science and Technology of China （Grant No 2002CCB00200）, and the Asia Europe Link project （Grant No CN/ASIA-LINK/008（94791）） of the European Commission.
文摘By using the new experimental data of AA potential, this paper has performed a full calculation for strange hadronic matter with different strangeness contents as well as its consequences on the global properties of neutron star matter in relativistic mean field model. It finds that the new weak hyperon-hyperon interaction makes the equations of state much stiffer than the result of the previous strong hyperon hyperon interaction, and even stiffer than the result without consideration of hyperon-hyperon interaction. This new hyperon-hyperon interaction results in a maximum mass of 1.75M⊙ （where M⊙ stands for the mass of the Sun）, about 0.2-0.5M⊙ larger than the previous prediction with the presence of hyperons. After examining carefully the onset densities of kaon condensation it finds that this new weak version of hyperon-hyperon interaction favours the occurrence of kaons in comparison with the strong one.
基金This research is financially supported by the National Natural Science Foundation of China(No.51678385).
文摘Indirect evaporative cooling(IEC)is a kind of high efficiency,energy-saving and environmental protection cooling technology,which has been widely used in data centers and other fields in recent years.In this paper,the optimized two-dimensional non-condensation state model of indirect evaporative cooling was proposed.Meanwhile the computer program was updated to solve the developed mathematical model under variable fresh air conditions.The optimized model was verified by the experimental data,and the maximum deviation was only 4.6%.Based on the modified model and the annual hourly meteorological parameters in Tianjin,China,it was analyzed the optimal heat transfer area of IEC used as fresh air pre-cooling unit under various air volumes to provide references for system design and equipment selection.Finally,taking an IEC-primary return air conditioning system of a gymnasium as an example,the hourly energy-saving effect of whole year was simulated by the developed IEC model.The simulation results showed that IEC could control the fresh air temperature below 27℃ and the moisture content below 18 g/kg throughout the year,and undertook 102.6% of the total fresh air cooling load.The findings are useful in future system optimization and design of IEC equipment.
基金supported by NSFC(Grants No.12135018,No.11974363,and No.12047503)NKRDPC(Grant No.2021YFA0718304)+1 种基金the Strategic Priority Research Program of CAS(Grant No.XDB28000000)support by the Youth Innovation Promotion Association CAS
文摘We investigate the ground-state properties and the dynamics of quasi-one-dimensional quantum droplets of binary Bose condensates by employing the Gaussian state theory.We show that there exists three quantum phases for the ground states of the droplets,including a coherent state and two macroscopic squeezed states.The phase transition between two macroscopic squeezed states is of the third order;while between the macroscopic squeezed state and the coherent is of a crossover type.As for the dynamics,we find that,by tuning the reduced scattering length to a negative value,a significant fraction of the atoms can be transferred from a coherent state to a macroscopic squeezed state.Our studies open up the possibility of generating macroscopic squeezed states using binary condensates.
基金supported by the National Natural Science Foundation of China(grant number:51906190)China Postdoctoral Science Foundation(2019M663702)+1 种基金Fundamental Research Funds for the Central Universities(xjh012019015)innovation team of Shaanxi province(2019TD-039)。
文摘The geometrical dimensions of the rough structures as well as the non-condensable gases in the vapor mixture can have the great effect on the nucleation position and the wetting state of the droplet,which further influence the condensation heat flux.In this paper,the multispecies multiphase lattice Boltzmann method together with a thermal phase change model is used to investigate the dropwise condensation on a rough surface enhanced with pillars.The effect of the geometric dimensions including pillar height H,pillar width W and pillar space S is investigated.Then the effect of non-condensable gases on the contact angle of a droplet on textured surface is studied.The results show that the local heat flux and the wetting area are higher while the waiting time is shorter at larger S,W and smaller H on the rough surface.The nucleation position rises from the bottom of grooves to the top with the increase of pillar height and the decrease of pillar space.The contact angle is larger and it is easier to maintain the Cassie state for droplet.When there exists non-condensable gas,the non-condensable gas obviously enhances the hydrophobicity of the rough surfaces compared with pure vapor.
基金Singapore Ministry of Education grant No.R-146-000-083-112 and would like to thank Professor Tao Tang for very helpful discussion on the subject.
文摘In this paper we propose a uniformly convergent numerical method for discretizing singularly perturbed nonlinear eigenvalue problems under constraints with applications in Bose-Einstein condensation and quantum chemistry.We begin with the time-independent Gross-Pitaevskii equation and show how to reformulate it into a singularly perturbed nonlinear eigenvalue problem under a constraint.Matched asymptotic approximations for the problem are presented to locate the positions and characterize the widths of boundary layers and/or interior layers in the solution.A uniformly convergent numerical method is proposed by using the normalized gradient flow and piecewise uniform mesh techniques based on the asymptotic approximations for the problem.Extensive numerical results are reported to demonstrate the effectiveness of our numerical method for the problems.Finally,the method is applied to compute ground and excited states of Bose-Einstein condensation in the semiclassical regime and some conclusive findings are reported.
