The time evolution of protons and 3He fragments from Au＋Au/Pb＋Pb reactions at 0.25, 2, and 20 GeV/nucleon is investigated with the potential version of the Ultrarelativistic Quantum Molecular Dynamics （UrQMD） mode...The time evolution of protons and 3He fragments from Au＋Au/Pb＋Pb reactions at 0.25, 2, and 20 GeV/nucleon is investigated with the potential version of the Ultrarelativistic Quantum Molecular Dynamics （UrQMD） model combined with the traditional coalescence afterburner. In the coalescence process, the relative distance R0 and relative momentum P0 are surveyed in the range of 3-4 fm and 0.25-0.35 GeV/c, respectively. For both clusters, a strong reversed correlation between R0 and Po is seen and it is time-dependent as well. For protons, the accepted （R0, P0） bands lie in the time interval 30-60 fm/c, while for 3He, a longer time evolution （at about 60-90 fm/c） is needed. Otherwise, much smaller R0 and P0 values should be chosen. If we further look at the rapidity distributions from both central and semi-central collisions, it is found that the accepted [tout, （R0, P0）] assemble can provide consistent results for proton yield and collective flows especially at mid-rapdities, while for 3He, the consistency is destroyed at both middle and projectile-target rapidities.展开更多
In general,heat transfers can be classified into two categories according to the purposes of object heating or cooling and the heat to work conversion.Recently,a new physical quantity,entransy(or potential energy),was...In general,heat transfers can be classified into two categories according to the purposes of object heating or cooling and the heat to work conversion.Recently,a new physical quantity,entransy(or potential energy),was proposed to describe the ability of heat transfer with the former purpose.This paper addresses the concept of potential energy in terms of the heat transfer processes for the latter purpose,named the conversion potential energy.The physical meaning of this newly introduced concept is the potential energy for the heat to work conversion stored in the equivalent mass of heat(thermomass) derived on the basis of the Einstein's special theory of relativity.The dissipation of conversion potential energy occurs during the real irreversible heat to work conversion processes as a measure of the conversion irreversibility.Finally,a heat to work conversion problem of a heat exchanger group is provided to show that the minimum conversion potential energy dissipation rate can be used as an optimization criterion for the heat transfer performance with the purpose of the heat to work conversion.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11375062,11547312,11275068,11505056 and11505057)SRF for ROCS,SEM and the Doctoral Scientific Research Foundation(Grant No.11447109)
文摘The time evolution of protons and 3He fragments from Au＋Au/Pb＋Pb reactions at 0.25, 2, and 20 GeV/nucleon is investigated with the potential version of the Ultrarelativistic Quantum Molecular Dynamics （UrQMD） model combined with the traditional coalescence afterburner. In the coalescence process, the relative distance R0 and relative momentum P0 are surveyed in the range of 3-4 fm and 0.25-0.35 GeV/c, respectively. For both clusters, a strong reversed correlation between R0 and Po is seen and it is time-dependent as well. For protons, the accepted （R0, P0） bands lie in the time interval 30-60 fm/c, while for 3He, a longer time evolution （at about 60-90 fm/c） is needed. Otherwise, much smaller R0 and P0 values should be chosen. If we further look at the rapidity distributions from both central and semi-central collisions, it is found that the accepted [tout, （R0, P0）] assemble can provide consistent results for proton yield and collective flows especially at mid-rapdities, while for 3He, the consistency is destroyed at both middle and projectile-target rapidities.
基金supported by the NUAA Research Funding (Grant No. NS2012142)
文摘In general,heat transfers can be classified into two categories according to the purposes of object heating or cooling and the heat to work conversion.Recently,a new physical quantity,entransy(or potential energy),was proposed to describe the ability of heat transfer with the former purpose.This paper addresses the concept of potential energy in terms of the heat transfer processes for the latter purpose,named the conversion potential energy.The physical meaning of this newly introduced concept is the potential energy for the heat to work conversion stored in the equivalent mass of heat(thermomass) derived on the basis of the Einstein's special theory of relativity.The dissipation of conversion potential energy occurs during the real irreversible heat to work conversion processes as a measure of the conversion irreversibility.Finally,a heat to work conversion problem of a heat exchanger group is provided to show that the minimum conversion potential energy dissipation rate can be used as an optimization criterion for the heat transfer performance with the purpose of the heat to work conversion.
