Based on the thermodynamic potential function of Fermi gas in a strong magnetic field, using the thermodynamics method, the integrated analytical expressions of thermodynamic quantities of the system at low temperatur...Based on the thermodynamic potential function of Fermi gas in a strong magnetic field, using the thermodynamics method, the integrated analytical expressions of thermodynamic quantities of the system at low temperatures are derived, and the effects of the magnetic field on the statistic properties of the system are analysed. It is shown that, as long as the temperature is not zero, the effects of the magnetic field on the thermodynamic quantities of the system contain both oscillatory and non-oscillatory parts. For the non-oscillatory part, compared with the situation of Fermi gas in a weak magnetic field, the influence of the magnetic field on the thermodynamic quantities is not exactly the same. For the oscillatory part, the period and amplitude of the oscillation are all related to the magnetic field. Due to the oscillation, the chemical potential may be greater than Ferim energy of the system, but the oscillation does not affect the thermodynamic stability of the system.展开更多
β decay in the strong magnetic field of the crusts of neutron stars is analysed by an improved method. The reactions ^67Ni（β-）^67Cu and ^62Mn（β-）^62Fe are investigated as examples. The results show that a weak ...β decay in the strong magnetic field of the crusts of neutron stars is analysed by an improved method. The reactions ^67Ni（β-）^67Cu and ^62Mn（β-）^62Fe are investigated as examples. The results show that a weak magnetic field has little effect on β decay but a strong magnetic field （B 〉 10^12G） increases β decay rates obviously. The conclusion derived may be crucial to the research of late evolution of neutron stars and nucleosynthesis in r-process.展开更多
The electron capture of Gamow--Teller transition on iron group nuclei is investigated in a strong magnetic. field at the crusts of neutron stars. The results show that the magnetic field has only a slight effect on th...The electron capture of Gamow--Teller transition on iron group nuclei is investigated in a strong magnetic. field at the crusts of neutron stars. The results show that the magnetic field has only a slight effect on the electron capture rates with the range of the magnetic fields （10^9 - 10^13 G） on surfaces of most neutron stars, whereas for some magnetars whose range of the magnetic field is 10^13 - 10^18 G, the electron capture rates of most iron group nuclei would be debased greatly and may be even decreased overrun 3 orders of magnitude by the strong magnetic field.展开更多
The chemical potential of electrons in a strong magnetic field is investigated. It is shown that the magnetic field has only a slight effect on electron chemical potential when B 〈 10^11 T, but electron chemical pote...The chemical potential of electrons in a strong magnetic field is investigated. It is shown that the magnetic field has only a slight effect on electron chemical potential when B 〈 10^11 T, but electron chemical potential will decrease greatly when B 〉 10^11 T. The effects of a strong magnetic field on electron capture rates for ^60Fe are discussed, and the result shows that the electron capture sharply decreases because of the strong magnetic field.展开更多
Using a full configuration-interaction method with Hylleraas-Gaussian basis function, this paper investigates the 1^10^＋, 1^1（-1）^＋ and 1^1（-2）6＋ states of the hydrogen negative ion in strong magnetic fields. T...Using a full configuration-interaction method with Hylleraas-Gaussian basis function, this paper investigates the 1^10^＋, 1^1（-1）^＋ and 1^1（-2）6＋ states of the hydrogen negative ion in strong magnetic fields. The total energies, electron detachment energies and derivatives of the total energy with respect to the magnetic field are presented as functions of magnetic field over a wide range of field strengths. Compared with the available theoretical data, the accuracy for the energies is enhanced significantly. The field regimes 3 〈 γ 〈 4 and 0.02 〈 γ 〈 0.05, in which the 1^1（-1）6＋ and 1^1（-2）^＋ states start to become bound, respectively, are also determined based on the calculated electron detachment energies.展开更多
In this paper, firstly, we investigate the neutrino emissivity from quark Urca process in strong magnetic field. Then, we discuss the heat capacity of strange stars in strong magnetic field. Finally, we give the cooli...In this paper, firstly, we investigate the neutrino emissivity from quark Urca process in strong magnetic field. Then, we discuss the heat capacity of strange stars in strong magnetic field. Finally, we give the cooling curve in strong magnetic field. In order to make a comparison, we also give the corresponding cooling curve in the case of null magnetic field. It turns out that strange stars cool faster in strong magnetic field than that without magnetic field.展开更多
In this paper electron capture on iron group nuclei in crusts of neutron stars in a strong magnetic field is investigated. The results show that the magnetic fields have only a slight effect on electron capture rates ...In this paper electron capture on iron group nuclei in crusts of neutron stars in a strong magnetic field is investigated. The results show that the magnetic fields have only a slight effect on electron capture rates in a range of 10^5 - 10^13g on surfaces of most neutron stars, whereas for some magnetars the magnetic fields range from 10^13 to 10^18 G. The electron capture rates of most iron group nuclei are greatly decreased, reduced by even four orders of magnitude due to the strong magnetic field.展开更多
A simple and efficient screening model for studying the effects of superstrong magnetic fields （such as those of magnetars） on thermonuclear reaction rates on magnetar surfaces is proposed in this paper. The most in...A simple and efficient screening model for studying the effects of superstrong magnetic fields （such as those of magnetars） on thermonuclear reaction rates on magnetar surfaces is proposed in this paper. The most interesting thermonuclear reactions, including hydrogen burning by the CNO cycle and helium burning by the triple alpha reaction, are investigated on the surface ofmagnetars. We find that the superstrong magnetic fields can increase the thermonuclear reaction rates by many orders of magnitude. The enhancement may have a dramatic effect on the thermonuclear runaways and bursts on the surfaces of magnetars.展开更多
Properties and deformations of the rotating neutron stars in uniform strong magnetic field are calculated. The magnetic field will soften the equation of state of the neutron star matters and make an obvious effect on...Properties and deformations of the rotating neutron stars in uniform strong magnetic field are calculated. The magnetic field will soften the equation of state of the neutron star matters and make an obvious effect on the structure of the rotating neutron star. If the magnetic field is superstrong （B=10^17 T）, the mass, radius, and the deformation will become smaller effectively.展开更多
By solving a time-dependent Schrodinger equation（TDSE）, we studied the electron capture process in the He^2＋＋ H collision system under a strong magnetic field in a wide projectile energy range. The strong enhancem...By solving a time-dependent Schrodinger equation（TDSE）, we studied the electron capture process in the He^2＋＋ H collision system under a strong magnetic field in a wide projectile energy range. The strong enhancement of the total charge transfer cross section is observed for the projectile energy below 2.0 ke V/u. With the projectile energy increasing, the cross sections will reduce a little and then increase again, compared with those in the field-free case. The cross sections to the states with different magnetic quantum numbers are presented and analyzed where the influence due to Zeeman splitting is obviously found, especially in the low projectile energy region. The comparison with other models is made and the tendency of the cross section varying with the projectile energy is found closer to that from other close coupling models.展开更多
Recently, U. Das and B. Mukhopadhyay proposed that the Chandrasekhar limit of a white dwarf could reach a new high level （2.58M） if a superstrong magnetic field were considered （Das U and Mukhopadhyay B 2013 Phys. ...Recently, U. Das and B. Mukhopadhyay proposed that the Chandrasekhar limit of a white dwarf could reach a new high level （2.58M） if a superstrong magnetic field were considered （Das U and Mukhopadhyay B 2013 Phys. Rev. Lett. 110 071102）, where the structure of the strongly magnetized white dwarf （SMWD） is calculated in the framework of Newtonian theory （NT）. As the SMWD has a far smaller size, in contrast with the usual expectation, we found that there is an obvious general relativistic effect （GRE） in the SMWD. For example, for the SMWD with a one Landau level system, the super-Chandrasekhar mass limit in general relativity （GR） is approximately 16.5% lower than that in NT. More interestingly, the maximal mass of the white dwarf will be first increased when the magnetic field strength keeps on increasing and reaches the maximal value M = 2.48MQ with BD = 391.5. Then if we further increase the magnetic fields, surprisingly, the maximal mass of the white dwarf will decrease when one takes the GRE into account.展开更多
We explore the deuteron under strong magnetic fields in Skyrme models.The effects of the derivative dependent sextic term in the Skyrme Lagrangian are investigated,and the rational map approximation is used to de-scri...We explore the deuteron under strong magnetic fields in Skyrme models.The effects of the derivative dependent sextic term in the Skyrme Lagrangian are investigated,and the rational map approximation is used to de-scribe the deuteron.The influences of strong magnetic fields on the electric charge distribution and mass of the deu-teron arediscussed.展开更多
Slanted Fe nanorods prepared by glancing angle deposition on silicon substrates exhibited easy magnetization along their growth axis. By using a thin gold film on a silicon substrate as a buffer layer, slanted Fe nano...Slanted Fe nanorods prepared by glancing angle deposition on silicon substrates exhibited easy magnetization along their growth axis. By using a thin gold film on a silicon substrate as a buffer layer, slanted Fe nanorods can be realigned towards the substrate surface normal by a strong magnetic field. After realignment, the Fe nanorods retained the easy magnetization axis along their growth axis. The effects of the realignment by the strong magnetic field on the properties of the slanted Fe nanorods were also investigated. This study provides a possible way to fabricate magnetic nanostructures for perpendicular recording applications.展开更多
Solidification of metals under a strong magnetic field is a new area for research.Here,some progress in the area is reviewed along with presentation of the fundamental effects of magnetic field.Focus is paid on the su...Solidification of metals under a strong magnetic field is a new area for research.Here,some progress in the area is reviewed along with presentation of the fundamental effects of magnetic field.Focus is paid on the subjects of influence of a magnetic field on kinetics of solidification,instability of S/L interface,crystal growth of monophase alloy, eutectic growth,thermoelectrical magnetic convection and its effects,The core problems which should be investigated deeply and the key parameters needed are discussed.展开更多
The pearlite transformation in a Mo-containing iron alloy was investigated under 12 T magnetic field. The pearlite transformation was accelerated owing to the application of a strong magnetic field. Pearlite was of de...The pearlite transformation in a Mo-containing iron alloy was investigated under 12 T magnetic field. The pearlite transformation was accelerated owing to the application of a strong magnetic field. Pearlite was of degenerated morphology without the presence of a strong magnetic field; but the degeneracy of pearlite is reduced when a strong magnetic field was applied, which may be attributed to the effect of strong magnetic field on faster carbon diffusion and less molybdenum segregation caused by a strong magnetic展开更多
In order to obtain homogenous Zn-Bi hyper-monotectic alloys and investigate what mechanism the magnetic field functions,we carried out the solidification experiments of Zn-4wt%Bi,5wt%Bi,6wt%Bi,7wt%Bi, 15wt%Bi and 30wt...In order to obtain homogenous Zn-Bi hyper-monotectic alloys and investigate what mechanism the magnetic field functions,we carried out the solidification experiments of Zn-4wt%Bi,5wt%Bi,6wt%Bi,7wt%Bi, 15wt%Bi and 30wt%Bi alloys under a 18T static magnetic field which was set up in LNCMI.Water quenching was also chosen to further damp the segregation caused by Stokes convection and Marangoni movement.The results indicated that when the content of Bismuth is 5-7wt%,the superimposition of 18Tesla magnetic field can damp the segregation remarkably,and the size of the second phase particles also is decreased.Furthermore,to Zn-4wt%Bi alloy solidified in 18T magnetic field,no spherical bismuth particles are found even magnifying 1000 times by microscope, which hints that the 18T magnetic field may change its solidifying character.To Zn-15wt%Bi and Zn-30wt%Bi alloy, due to their strong segregation trend,the 18T magnetic field still cannot damp the Stokes settlement thoroughly even by quenching way,however,no layered bismuth and zinc appears when compared to 0T,large Bismuth block are formed in the lower half part of the sample.展开更多
In this paper,the Debye mass of quarks is investigated in the Nambu–Jona-Lasinio model at zero and nonzero chemical potentials.In a uniform plasma,the Debye mass usually behaves as a monotonous increasing function of...In this paper,the Debye mass of quarks is investigated in the Nambu–Jona-Lasinio model at zero and nonzero chemical potentials.In a uniform plasma,the Debye mass usually behaves as a monotonous increasing function of the temperature,the chemical potential and the magnetic field.At the fixed coupling interaction G,we find that the magnetic catalysis(MC)on the occurrence of the chiral restoration could be revealed by the susceptibility of the Debye mass dmD/dT at low chemical potential and by the quantity TdmD/dT in the region of moderate densities.However,the inverse MC is realized under a thermomagnetic coupling constant G(B,T)by the behavior of the Debye mass at both zero and nonzero chemical potentials.展开更多
Effects of strong magnetic fields on the columnar-to-equiaxed transition(CET) have been investigated experimentally.Experimental results show that the application of a strong magnetic field causes a dendrite fragmenta...Effects of strong magnetic fields on the columnar-to-equiaxed transition(CET) have been investigated experimentally.Experimental results show that the application of a strong magnetic field causes a dendrite fragmentation and then the CET.The thermoelectric magnetic force acting on cells/dendrites and equiaxed grains in the mushy zone has been studied numerically.Numerical results reveal that a torque is created on cells/dendrites and equiaxed grains and the value of the thermoelectric magnetic force increases as the magnetic field intensity increase.This torque breaks cells/dendrites and drives the rotation of equiaxed grains.As a consequence,the CET will occur during directional solidification under a strong magnetic field.This may initiate a new method to induce the CET via an applied strong magnetic field during directional solidification.展开更多
In this paper, the recent studies of laboratory astrophysics with strong magnetic fields in China have been reviewed.On the Shenguang-II laser facility of the National Laboratory on High-Power Lasers and Physics, a la...In this paper, the recent studies of laboratory astrophysics with strong magnetic fields in China have been reviewed.On the Shenguang-II laser facility of the National Laboratory on High-Power Lasers and Physics, a laser-driven strong magnetic field up to 200 T has been achieved. The experiment was performed to model the interaction of solar wind with dayside magnetosphere. Also the low beta plasma magnetic reconnection(MR) has been studied. Theoretically, the model has been developed to deal with the atomic structures and processes in strong magnetic field. Also the study of shock wave generation in the magnetized counter-streaming plasmas is introduced.展开更多
We study the effects of strong magnetic fields and uniform rotation on the properties of soliton stars in Lee-Wick model when a temperature dependence is introduced into this model. We first recall the properties of t...We study the effects of strong magnetic fields and uniform rotation on the properties of soliton stars in Lee-Wick model when a temperature dependence is introduced into this model. We first recall the properties of the Lee-Wick model and study the properties of soliton solutions, in particular, the stability condition, in terms of the parameters of the model and in terms of the number of fermions N inside the soliton (for very large N) in the presence of strong magnetic fields and uniform rotation. We also calculate the effects of gravity on the stability properties of the soliton stars in the simple approximation of coupling the Newtonian gravitational field to the energy density inside the soliton, treating this as constant throughout. Following Cottingham and Vinh Mau, we also make an analysis at finite temperature and show the possibility of a phase transition which leads to a model with parameters similar to those considered by Lee and his colleagues but in the presence of magnetic fields and rotation. More specifically, the effects of magnetic fields and rotation on the soliton mass and transition temperature are computed explicitly. We finally study the evolution on these magnetized and rotating soliton stars with the temperature from the early universe to the present time.展开更多
文摘Based on the thermodynamic potential function of Fermi gas in a strong magnetic field, using the thermodynamics method, the integrated analytical expressions of thermodynamic quantities of the system at low temperatures are derived, and the effects of the magnetic field on the statistic properties of the system are analysed. It is shown that, as long as the temperature is not zero, the effects of the magnetic field on the thermodynamic quantities of the system contain both oscillatory and non-oscillatory parts. For the non-oscillatory part, compared with the situation of Fermi gas in a weak magnetic field, the influence of the magnetic field on the thermodynamic quantities is not exactly the same. For the oscillatory part, the period and amplitude of the oscillation are all related to the magnetic field. Due to the oscillation, the chemical potential may be greater than Ferim energy of the system, but the oscillation does not affect the thermodynamic stability of the system.
基金Project suoported by the National Natural Science Foundation of China （Grant No 10347008）.
文摘β decay in the strong magnetic field of the crusts of neutron stars is analysed by an improved method. The reactions ^67Ni（β-）^67Cu and ^62Mn（β-）^62Fe are investigated as examples. The results show that a weak magnetic field has little effect on β decay but a strong magnetic field （B 〉 10^12G） increases β decay rates obviously. The conclusion derived may be crucial to the research of late evolution of neutron stars and nucleosynthesis in r-process.
基金The project supported by National Natural Science Foundation of China under Grant No.10778719the Scientific Research Fund of the Education Department of Sichuan Province under Grant No.2006A079the Science and Technological Foundation of China West Normal University
文摘The electron capture of Gamow--Teller transition on iron group nuclei is investigated in a strong magnetic. field at the crusts of neutron stars. The results show that the magnetic field has only a slight effect on the electron capture rates with the range of the magnetic fields （10^9 - 10^13 G） on surfaces of most neutron stars, whereas for some magnetars whose range of the magnetic field is 10^13 - 10^18 G, the electron capture rates of most iron group nuclei would be debased greatly and may be even decreased overrun 3 orders of magnitude by the strong magnetic field.
基金supported by the National Natural Science Foundation of China (Grant No.10778719)
文摘The chemical potential of electrons in a strong magnetic field is investigated. It is shown that the magnetic field has only a slight effect on electron chemical potential when B 〈 10^11 T, but electron chemical potential will decrease greatly when B 〉 10^11 T. The effects of a strong magnetic field on electron capture rates for ^60Fe are discussed, and the result shows that the electron capture sharply decreases because of the strong magnetic field.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10874133)
文摘Using a full configuration-interaction method with Hylleraas-Gaussian basis function, this paper investigates the 1^10^＋, 1^1（-1）^＋ and 1^1（-2）6＋ states of the hydrogen negative ion in strong magnetic fields. The total energies, electron detachment energies and derivatives of the total energy with respect to the magnetic field are presented as functions of magnetic field over a wide range of field strengths. Compared with the available theoretical data, the accuracy for the energies is enhanced significantly. The field regimes 3 〈 γ 〈 4 and 0.02 〈 γ 〈 0.05, in which the 1^1（-1）6＋ and 1^1（-2）^＋ states start to become bound, respectively, are also determined based on the calculated electron detachment energies.
基金supported by National Natural Science Foundation of China under Grant No.10778719
文摘In this paper, firstly, we investigate the neutrino emissivity from quark Urca process in strong magnetic field. Then, we discuss the heat capacity of strange stars in strong magnetic field. Finally, we give the cooling curve in strong magnetic field. In order to make a comparison, we also give the corresponding cooling curve in the case of null magnetic field. It turns out that strange stars cool faster in strong magnetic field than that without magnetic field.
基金Project supported by the National Natural Science Foundation of China （Grant No 10347008）.
文摘In this paper electron capture on iron group nuclei in crusts of neutron stars in a strong magnetic field is investigated. The results show that the magnetic fields have only a slight effect on electron capture rates in a range of 10^5 - 10^13g on surfaces of most neutron stars, whereas for some magnetars the magnetic fields range from 10^13 to 10^18 G. The electron capture rates of most iron group nuclei are greatly decreased, reduced by even four orders of magnitude due to the strong magnetic field.
基金Project supported by the National Natural Science Foundation of China (Grant No 10778719)the Scientific Research and Fund of Sichuan Provincial Education Department, China (Grant No 2006A079)the Science and Technological Foundation of China West Normal University, China
文摘A simple and efficient screening model for studying the effects of superstrong magnetic fields （such as those of magnetars） on thermonuclear reaction rates on magnetar surfaces is proposed in this paper. The most interesting thermonuclear reactions, including hydrogen burning by the CNO cycle and helium burning by the triple alpha reaction, are investigated on the surface ofmagnetars. We find that the superstrong magnetic fields can increase the thermonuclear reaction rates by many orders of magnitude. The enhancement may have a dramatic effect on the thermonuclear runaways and bursts on the surfaces of magnetars.
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10647116 and 10575140 and the China Postdoctoral Science Foundation under Grant No. 2005037175
文摘Properties and deformations of the rotating neutron stars in uniform strong magnetic field are calculated. The magnetic field will soften the equation of state of the neutron star matters and make an obvious effect on the structure of the rotating neutron star. If the magnetic field is superstrong （B=10^17 T）, the mass, radius, and the deformation will become smaller effectively.
基金Project supported by the National Natural Science Foundation of China(Grants Nos.11104017,11025417,11275029,and 11474032)the National Basic Research Programm of China(Grant No.2013CB922200)the Foundation for the Development of Science and Technology of the Chinese Academy of Engineering Physics(Grant Nos.2014B09036 and 2013A0102005)
文摘By solving a time-dependent Schrodinger equation（TDSE）, we studied the electron capture process in the He^2＋＋ H collision system under a strong magnetic field in a wide projectile energy range. The strong enhancement of the total charge transfer cross section is observed for the projectile energy below 2.0 ke V/u. With the projectile energy increasing, the cross sections will reduce a little and then increase again, compared with those in the field-free case. The cross sections to the states with different magnetic quantum numbers are presented and analyzed where the influence due to Zeeman splitting is obviously found, especially in the low projectile energy region. The comparison with other models is made and the tendency of the cross section varying with the projectile energy is found closer to that from other close coupling models.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.10947023,11275073,and 11305063)the Fundamental Research Funds for the Central University of China(Grant Nos.2014ZG0036 and 2013ZM107)sponsored by the Science Research Foundation for Returned Overseas Chinese Scholars,SEM,and has made use of NASA’s Astrophysics Data System
文摘Recently, U. Das and B. Mukhopadhyay proposed that the Chandrasekhar limit of a white dwarf could reach a new high level （2.58M） if a superstrong magnetic field were considered （Das U and Mukhopadhyay B 2013 Phys. Rev. Lett. 110 071102）, where the structure of the strongly magnetized white dwarf （SMWD） is calculated in the framework of Newtonian theory （NT）. As the SMWD has a far smaller size, in contrast with the usual expectation, we found that there is an obvious general relativistic effect （GRE） in the SMWD. For example, for the SMWD with a one Landau level system, the super-Chandrasekhar mass limit in general relativity （GR） is approximately 16.5% lower than that in NT. More interestingly, the maximal mass of the white dwarf will be first increased when the magnetic field strength keeps on increasing and reaches the maximal value M = 2.48MQ with BD = 391.5. Then if we further increase the magnetic fields, surprisingly, the maximal mass of the white dwarf will decrease when one takes the GRE into account.
基金Supported by the Changsha Municipal Natural Science Foundation(kq2007004)the Science Research Key Project of Education Department of Hunan Province(21A0186)the Construct Program of the Key Discipline in Hunan province。
文摘We explore the deuteron under strong magnetic fields in Skyrme models.The effects of the derivative dependent sextic term in the Skyrme Lagrangian are investigated,and the rational map approximation is used to de-scribe the deuteron.The influences of strong magnetic fields on the electric charge distribution and mass of the deu-teron arediscussed.
基金The authors are grateful for financial support from the National Natural Science Foundation of China(No.50931002)and the National Basic Research Program of China(973 Program,No.2007CB-936601).
文摘Slanted Fe nanorods prepared by glancing angle deposition on silicon substrates exhibited easy magnetization along their growth axis. By using a thin gold film on a silicon substrate as a buffer layer, slanted Fe nanorods can be realigned towards the substrate surface normal by a strong magnetic field. After realignment, the Fe nanorods retained the easy magnetization axis along their growth axis. The effects of the realignment by the strong magnetic field on the properties of the slanted Fe nanorods were also investigated. This study provides a possible way to fabricate magnetic nanostructures for perpendicular recording applications.
基金Item Sponsored by National Basic Research Program of China (973 Program) [2011CB610404]Natioanl Natural Science Foundation of China[No.50911130365]Shanghai Science and Technology Committee (08DZ1130100)
文摘Solidification of metals under a strong magnetic field is a new area for research.Here,some progress in the area is reviewed along with presentation of the fundamental effects of magnetic field.Focus is paid on the subjects of influence of a magnetic field on kinetics of solidification,instability of S/L interface,crystal growth of monophase alloy, eutectic growth,thermoelectrical magnetic convection and its effects,The core problems which should be investigated deeply and the key parameters needed are discussed.
基金support for this research from State Ministry of Education (No.NCET-05-0680)support from Natural Science Foundation of Hubei Province (No.2006ABB037)
文摘The pearlite transformation in a Mo-containing iron alloy was investigated under 12 T magnetic field. The pearlite transformation was accelerated owing to the application of a strong magnetic field. Pearlite was of degenerated morphology without the presence of a strong magnetic field; but the degeneracy of pearlite is reduced when a strong magnetic field was applied, which may be attributed to the effect of strong magnetic field on faster carbon diffusion and less molybdenum segregation caused by a strong magnetic
基金Item Sponsored by National Science Foundation of China (No.50974085No.51034010) +5 种基金Development Foundation for Talents in Shanghai (No.2009046) National High-tech R&D Program of China (No.2009AA03Z109) Key Research and Innovation Program from Shanghai Municipal Education Commission (No.09zz98) Key Project from Science and Technology Commission of Shanghai Municipality (No:09dz120640109dz1206402) EuroMagNET under the EU contract n 228043
文摘In order to obtain homogenous Zn-Bi hyper-monotectic alloys and investigate what mechanism the magnetic field functions,we carried out the solidification experiments of Zn-4wt%Bi,5wt%Bi,6wt%Bi,7wt%Bi, 15wt%Bi and 30wt%Bi alloys under a 18T static magnetic field which was set up in LNCMI.Water quenching was also chosen to further damp the segregation caused by Stokes convection and Marangoni movement.The results indicated that when the content of Bismuth is 5-7wt%,the superimposition of 18Tesla magnetic field can damp the segregation remarkably,and the size of the second phase particles also is decreased.Furthermore,to Zn-4wt%Bi alloy solidified in 18T magnetic field,no spherical bismuth particles are found even magnifying 1000 times by microscope, which hints that the 18T magnetic field may change its solidifying character.To Zn-15wt%Bi and Zn-30wt%Bi alloy, due to their strong segregation trend,the 18T magnetic field still cannot damp the Stokes settlement thoroughly even by quenching way,however,no layered bismuth and zinc appears when compared to 0T,large Bismuth block are formed in the lower half part of the sample.
基金The authors would like to thank support from the National Natural Science Foundation of China under the Grant Nos.11875181,12147215,and 11705163This work was also sponsored by the Fund for Shanxi‘1331 Project’Key Subjects Construction.
文摘In this paper,the Debye mass of quarks is investigated in the Nambu–Jona-Lasinio model at zero and nonzero chemical potentials.In a uniform plasma,the Debye mass usually behaves as a monotonous increasing function of the temperature,the chemical potential and the magnetic field.At the fixed coupling interaction G,we find that the magnetic catalysis(MC)on the occurrence of the chiral restoration could be revealed by the susceptibility of the Debye mass dmD/dT at low chemical potential and by the quantity TdmD/dT in the region of moderate densities.However,the inverse MC is realized under a thermomagnetic coupling constant G(B,T)by the behavior of the Debye mass at both zero and nonzero chemical potentials.
基金Item Sponsored by National natural Science Foundation of China(No.51171106 and 2011CB610404)the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning
文摘Effects of strong magnetic fields on the columnar-to-equiaxed transition(CET) have been investigated experimentally.Experimental results show that the application of a strong magnetic field causes a dendrite fragmentation and then the CET.The thermoelectric magnetic force acting on cells/dendrites and equiaxed grains in the mushy zone has been studied numerically.Numerical results reveal that a torque is created on cells/dendrites and equiaxed grains and the value of the thermoelectric magnetic force increases as the magnetic field intensity increase.This torque breaks cells/dendrites and drives the rotation of equiaxed grains.As a consequence,the CET will occur during directional solidification under a strong magnetic field.This may initiate a new method to induce the CET via an applied strong magnetic field during directional solidification.
基金supported by National Basic Research Program of China (973 Program) under grant No.2013CBA01503the National Natural Science Foundation of China under grant No.11573040, 11503041 and 11135012supported by the Science Challenge Program
文摘In this paper, the recent studies of laboratory astrophysics with strong magnetic fields in China have been reviewed.On the Shenguang-II laser facility of the National Laboratory on High-Power Lasers and Physics, a laser-driven strong magnetic field up to 200 T has been achieved. The experiment was performed to model the interaction of solar wind with dayside magnetosphere. Also the low beta plasma magnetic reconnection(MR) has been studied. Theoretically, the model has been developed to deal with the atomic structures and processes in strong magnetic field. Also the study of shock wave generation in the magnetized counter-streaming plasmas is introduced.
文摘We study the effects of strong magnetic fields and uniform rotation on the properties of soliton stars in Lee-Wick model when a temperature dependence is introduced into this model. We first recall the properties of the Lee-Wick model and study the properties of soliton solutions, in particular, the stability condition, in terms of the parameters of the model and in terms of the number of fermions N inside the soliton (for very large N) in the presence of strong magnetic fields and uniform rotation. We also calculate the effects of gravity on the stability properties of the soliton stars in the simple approximation of coupling the Newtonian gravitational field to the energy density inside the soliton, treating this as constant throughout. Following Cottingham and Vinh Mau, we also make an analysis at finite temperature and show the possibility of a phase transition which leads to a model with parameters similar to those considered by Lee and his colleagues but in the presence of magnetic fields and rotation. More specifically, the effects of magnetic fields and rotation on the soliton mass and transition temperature are computed explicitly. We finally study the evolution on these magnetized and rotating soliton stars with the temperature from the early universe to the present time.
