Understanding the impulse discharge behaviour of natural ester(NE)is crucial for its safe application in high-voltage transformers.The ionisation potential(IP)of triglycerides plays a significant role in the process o...Understanding the impulse discharge behaviour of natural ester(NE)is crucial for its safe application in high-voltage transformers.The ionisation potential(IP)of triglycerides plays a significant role in the process of molecular ionisation during impulse discharge for NE.The correlation coefficients between molecular size,frontier orbital,electrostatic potential,polarity,and IP were analysed.And the quantitative microstructure-IP model for triglycerides were built,which revealed that IP is strongly related to the highest occupied molecular orbital(HOMO)energy EHM,as well as the average value of positive electrostatic potential V_(p)(t),the average value of negative electrostatic potential V_(p)(-),and the surface area of negative electrostatic potential S(-).The HOMO and negative electrostatic potentials of saturated triglycerides are predominantly linked to the carbonyl O atoms.Conversely,in unsaturated triglycerides,the influence of C=C double bonds on HOMO and negative electrostatic potentials is more pronounced.Therefore,the IP of unsaturated NE with C=C bonds is lower than that of saturated NE,rendering it more susceptible to ionisation under a strong electric field which is unfavourable for impulse breakdown voltage.The structure-property correlation analysis is valuable for understanding ionisation mechanism during the impulse discharge breakdown of NE at the microscopic level.展开更多
Utilizing the PYTHIA8 Angantyr model,which incorporates the multiple-parton interaction(MPI)based color reconnection(CR)mechanism,we study the relative neutron density fluctuation and neutron-proton correlation in Au+...Utilizing the PYTHIA8 Angantyr model,which incorporates the multiple-parton interaction(MPI)based color reconnection(CR)mechanism,we study the relative neutron density fluctuation and neutron-proton correlation in Au+Au collisions at√sNN=7.7,11.5,14.5,19.6,27,39,62.4,and 200 GeV.In this study,we not only delve into the dependence of these two remarkable observations on rapidity,centrality,and energy,but also analyze their interplay with the MPI and CR.Our results show that the light nuclei yield ratio of protons,deuterons,and tritons,expressed by the elegant expression N_(t)N_(p)/N^(d)^(2),remains unchanged even as the rapidity coverage and collision centrality increase.Interestingly,we also reveal that the effect of CR is entirely dependent on the presence of the MPI;CR has no impact on the yield ratio if the MPI is off.Our findings further demonstrate that the light nuclei yield ratio experiences a slight increase with increasing collision energy,as predicted by the PYTHIA8 Angantyr model;however,it cannot describe the non-monotonic trend observed by the STAR experiment.Based on the Angantyr model simulation results,it is essential not to overlook the correlation between neutron and proton fluctuations.The Angantyr model is a good baseline for studying collisions in the absence of a quark-gluon plasma system,given its lack of flow and jet quenching.展开更多
基金Science and Technology Project of State Grid Corporation of China,Grant/Award Number:5500-202327118A-1-1-ZNNational Natural Science Foundation of China,Grant/Award Number:52077015。
文摘Understanding the impulse discharge behaviour of natural ester(NE)is crucial for its safe application in high-voltage transformers.The ionisation potential(IP)of triglycerides plays a significant role in the process of molecular ionisation during impulse discharge for NE.The correlation coefficients between molecular size,frontier orbital,electrostatic potential,polarity,and IP were analysed.And the quantitative microstructure-IP model for triglycerides were built,which revealed that IP is strongly related to the highest occupied molecular orbital(HOMO)energy EHM,as well as the average value of positive electrostatic potential V_(p)(t),the average value of negative electrostatic potential V_(p)(-),and the surface area of negative electrostatic potential S(-).The HOMO and negative electrostatic potentials of saturated triglycerides are predominantly linked to the carbonyl O atoms.Conversely,in unsaturated triglycerides,the influence of C=C double bonds on HOMO and negative electrostatic potentials is more pronounced.Therefore,the IP of unsaturated NE with C=C bonds is lower than that of saturated NE,rendering it more susceptible to ionisation under a strong electric field which is unfavourable for impulse breakdown voltage.The structure-property correlation analysis is valuable for understanding ionisation mechanism during the impulse discharge breakdown of NE at the microscopic level.
基金Supported in part by the Natural Science Foundation of Henan Province,China (212300410386)the Key Research Projects of Henan Higher Education Institutions (20A140024)+3 种基金the Scientific Research Foundation of Hubei University of Education for Talent Introduction (ESRC20220028,ESRC20230002)the NSFC(12005114)NSFC key Grant (12061141008)the Key Laboratory of Quark and Lepton Physics (MOE) in the Central China Normal University(QLPL2022P01)
文摘Utilizing the PYTHIA8 Angantyr model,which incorporates the multiple-parton interaction(MPI)based color reconnection(CR)mechanism,we study the relative neutron density fluctuation and neutron-proton correlation in Au+Au collisions at√sNN=7.7,11.5,14.5,19.6,27,39,62.4,and 200 GeV.In this study,we not only delve into the dependence of these two remarkable observations on rapidity,centrality,and energy,but also analyze their interplay with the MPI and CR.Our results show that the light nuclei yield ratio of protons,deuterons,and tritons,expressed by the elegant expression N_(t)N_(p)/N^(d)^(2),remains unchanged even as the rapidity coverage and collision centrality increase.Interestingly,we also reveal that the effect of CR is entirely dependent on the presence of the MPI;CR has no impact on the yield ratio if the MPI is off.Our findings further demonstrate that the light nuclei yield ratio experiences a slight increase with increasing collision energy,as predicted by the PYTHIA8 Angantyr model;however,it cannot describe the non-monotonic trend observed by the STAR experiment.Based on the Angantyr model simulation results,it is essential not to overlook the correlation between neutron and proton fluctuations.The Angantyr model is a good baseline for studying collisions in the absence of a quark-gluon plasma system,given its lack of flow and jet quenching.
