The exploration of reaction dynamics,particularly the breakup and fusion mechanisms of proton drip-line nuclei at energies around the Coulomb barrier,is crucial in the feld of nuclear physics.This study reviews experi...The exploration of reaction dynamics,particularly the breakup and fusion mechanisms of proton drip-line nuclei at energies around the Coulomb barrier,is crucial in the feld of nuclear physics.This study reviews experimental investigations on the reactions induced by proton-rich nuclei,^(7)Be,^(8)B,and^(17)F,including elastic scattering and direct and fusion reactions at the near-barrier energies.In particular,we briefy introduce complete kinematic measurements of^(8)B+^(120)Sn and^(17)F+^(58)Ni at the energies of interest.Distinct reaction dynamics are observed for proton-rich nuclei compared with neutron-rich nuclei.展开更多
The pygmy and giant dipole resonances in proton-rich nuclei 17,1817,18Ne are investigated with a fully self-consistent approach. The properties of ground states are calculated in the Skyrme Hartree–Fock with the Bard...The pygmy and giant dipole resonances in proton-rich nuclei 17,1817,18Ne are investigated with a fully self-consistent approach. The properties of ground states are calculated in the Skyrme Hartree–Fock with the Bardeen–Cooper–Schrieffer approximation to take into account the pairing correlation. The quasiparticle random phase approximation （QRPA） method is used to explore the properties of excited dipole states. In the calculations the SLy5 Skyrme interaction is employed. In addition to the giant dipole resonances, pygmy dipole resonances （PDR） are found to be located in the energy region below 10 MeV in both ^17,18Ne. The strength and transition density show that the low-lying states are typical PDR states. However, analyzing the QRPA amplitudes of proton and neutron 2 quasiparticle （2qp） configurations for a given low-lying state in ^17,18Ne, we find that the PDR state is less collective, more like a single 2qp excitation.展开更多
The neutron-to-proton and3 H-to-3 He yield ratios, and the directed flows of particles dependent on a reduced rapidity, the transverse momentum per nucleon,and a reduced impact parameter are investigated for ^(28)S+^(...The neutron-to-proton and3 H-to-3 He yield ratios, and the directed flows of particles dependent on a reduced rapidity, the transverse momentum per nucleon,and a reduced impact parameter are investigated for ^(28)S+^(28)Si and ^(32)S+^(28)Si systems at 50 and 400 MeV/u using an isospin-dependent quantum molecular dynamics model.The results show that these yield ratios of projectile-like fragments are approximately equal to the constituent neutron-to-proton ratio of the projectile. There are clear differences of the directed flows for isospin-related fragments neutron and proton,~3H and ~3He from ^(28)S+^(28)Si collisions.The differences in directed flows for neutrons and protons and ~3H–~3He from a proton-rich nucleus ^(28)S- induced collisions are noticeably larger than those from a stable nucleus ^(32)S- induced reactions under medium impact parameters. Thus, the yield ratios and differences in directed flows for the neutrons and protons and ~3H–~3He under medium impact parameters are proposed as possible observable items for studying isospin physics.展开更多
We investigate the cross sections of the elastic electron or positron scat tering from 208 Pb, ^12C ^12,16O and ^28,32S by the relativistic partial-wave expansion method using the static charge density distribution fr...We investigate the cross sections of the elastic electron or positron scat tering from 208 Pb, ^12C ^12,16O and ^28,32S by the relativistic partial-wave expansion method using the static charge density distribution from the self-consistent relativistic mean fiel model and also calculate the charge form factor for ^12＇16O and ^28,32S. The numerical results are compared with the available data. Calculations indicate that the extended charge density distributions of ^12O and ^28S have observable effects on the cross sections of the electron or positron scattering as well as the charge form factors.展开更多
We investigate the half-lives of β + /EC(electron capture) decay using the proton-neutron quasiparticle random-phase approximation(pnQRPA) with a δ-form Gamow-Teller residual interaction.Both particle-hole and parti...We investigate the half-lives of β + /EC(electron capture) decay using the proton-neutron quasiparticle random-phase approximation(pnQRPA) with a δ-form Gamow-Teller residual interaction.Both particle-hole and particle-particle residual interactions are consistently introduced in dealing with the pnQRPA matrix equation.The sensitivity of the calculated half-lives to some physical quantities used in the calculations is examined.Calculations are performed for even-even neutron-deficient isotopes ranging from Z = 10 to Z = 76.Good agreement between experiment and theory is achieved especially for the nuclei far from stability,and the results of our calculations are discussed with comparison with other theoretical results.Predictions on the β-decay half-lives of some very neutron-deficient nuclei are also given for reference in future experiments.展开更多
In addition to the Coulomb displacement energy,the residual differences between the binding energies of mirror nuclei(a pair of nuclei with the same mass number plus interchanged proton and neutron numbers)contribute ...In addition to the Coulomb displacement energy,the residual differences between the binding energies of mirror nuclei(a pair of nuclei with the same mass number plus interchanged proton and neutron numbers)contribute to the shell effect via the valence scheme in this study.To this end,one linear combining type of valence nucleon number,namely,αNp+βNn,is chosen to tackle this shell correction,in which Npand Nnare the valence proton and neutron numbers with respect to the nearest shell closure,respectively.The mass differences of mirror nuclei,as the sum of the empirical Coulomb displacement energy and shell effect correction,are then used to obtain the binding energies of proton-rich nuclei through the available data of their mirror partners to explore the proton dripline of the nuclear chart.展开更多
The direct proton capture and resonance proton capture properties of stellar reactions 22Mg(p,γ)23Al and 26Si(p,γ)27P are studied by employing a mean-field potential obtained from the Skyrme-Hartree-Fock(SHF) model....The direct proton capture and resonance proton capture properties of stellar reactions 22Mg(p,γ)23Al and 26Si(p,γ)27P are studied by employing a mean-field potential obtained from the Skyrme-Hartree-Fock(SHF) model.Calculations with the SHF potential reproduce well the loosely-bound structure of the ground states as well as the widths of the resonant states in these nuclei.With the obtained potential we estimate the reaction rates of direct proton capture and resonance proton capture to nuclei 23Al and 27P.The effect of the 27P loosely-bound structure on the S factor of the direct proton capture is also discussed.展开更多
Multinucleon transfer reactions near the Coulomb barrier are investigated based on the improved dinuclear system(DNS)model,and the deexcitation process of primary fragments are described using the statistical model GE...Multinucleon transfer reactions near the Coulomb barrier are investigated based on the improved dinuclear system(DNS)model,and the deexcitation process of primary fragments are described using the statistical model GEMINI++.The production cross sections of^(40,48)Ca+^(124)Sn and^(64)Ni+^(130)Te based on the DNS model+GEMINI++are calculated and compared with experimental data.The calculated results reproduce experimental data.The cross sections of fusion-evaporation,fragmentation,and multinucleon transfer reactions in the region are also provided in this paper.The results show that in the region,fusion-evaporation and fragmentation reactions have good results in the relatively proton-rich region,but in the extreme proton-deficient region,the MNT reaction is still promising for synthesizing proton-rich nuclei.展开更多
In this study,the chemical freeze-out of hadrons,including light-and strange-flavor particles and light nuclei,produced in Au+Au collisions at the Relativistic Heavy Ion Collider(RHIC),was investigated.Using the Therm...In this study,the chemical freeze-out of hadrons,including light-and strange-flavor particles and light nuclei,produced in Au+Au collisions at the Relativistic Heavy Ion Collider(RHIC),was investigated.Using the Thermal-FIST thermodynamic statistical model,we analyzed various particle sets:those inclusive of light nuclei,those exclusive to light nuclei,and those solely comprising light nuclei.We determined the chemical freeze-out parameters at√^(S)NN=7.7–200 Ge V and four different centralities.A significant finding was the decrease in the chemical freeze-out temperature T_(ch)with light-nuclei inclusion,with an even more pronounced reduction when considering light-nuclei yields exclusively.This suggests that light-nuclei formation occurs at a later stage in the system’s evolution at RHIC energies.We present parameterized formulas that describe the energy dependence of T_(ch)and the baryon chemical potentialμ_(B) for three distinct particle sets in central Au+Au collisions at RHIC energies.Our results reveal at least three distinct T_(ch)at RHIC energies correspond to different freeze-out hypersurfaces:a light-flavor freeze-out temperature of T_L=150.2±6 Me V,a strange-flavor freeze-out temperature T_s=165.1±2.7 Me V,and a light-nuclei freeze-out temperature T_(ln)=141.7±1.4 Me V.Notably,at the Large Hadron Collider(LHC)Pb+Pb 2.76Te V,the expected lower freeze-out temperature for light nuclei was not observed;instead,the T_(ch)for light nuclei was found to be approximately 10 Me V higher than that for light-flavor hadrons.展开更多
This paper provides a comprehensive analysis of all stages of the heavy-ion fusion evaporation reaction,aiming to enhance the understanding of the entire process and identify the influencing factors in calculating the...This paper provides a comprehensive analysis of all stages of the heavy-ion fusion evaporation reaction,aiming to enhance the understanding of the entire process and identify the influencing factors in calculating the evaporation residue cross-section.By focusing on the synthesis of superheavy nuclei with Z=114,we discuss the capture cross-section,fusion probability,and survival probability of the ^(48)Ca+^(244)Pu reaction and compare them with those of the 40Ar+248Cm reaction.Moreover,a systematic study examined the evaporation residue cross-sections for the synthesis of superheavy nuclei with Z=112-116 using ^(40)Ar as the projectile nucleus.The results indicate that utilizing ^(40)Ar as the projectile nucleus for synthesizing isotopes with Z=114 offers advantages such as lower incident energy and reduced experimental costs.Furthermore,using ^(40)Ar as the projectile nucleus enables the synthesis of a new key isotope,285115,thereby facilitating its identification.展开更多
In this study,we explore the impact of state-of-the-art laser fields on theαdecay half-life of deformed ground-state odd-A nuclei within the proton number range of 52–107.The calculations show that the presence of a...In this study,we explore the impact of state-of-the-art laser fields on theαdecay half-life of deformed ground-state odd-A nuclei within the proton number range of 52–107.The calculations show that the presence of a laser field modulates theαdecay half-life by altering theαdecay penetration probability within a limited range.Moreover,the variance in the penetration probability rate of change between even–odd and odd–even nuclei is investigated.Furthermore,we investigate the rate of change of the penetration probability for the same parent nucleus with different neutron numbers,based on the characteristics of the odd-A nucleus.We found that the influence of the laser field on the penetration probability is determined by both the shell effect and odd–even staggering.This research contributes to the understanding of nuanced interactions between laser fields and nuclear decay processes.Therefore,valuable insights for future experiments in laser–nuclear physics are attainable using this study.展开更多
Nuclei segmentation is a challenging task in histopathology images.It is challenging due to the small size of objects,low contrast,touching boundaries,and complex structure of nuclei.Their segmentation and counting pl...Nuclei segmentation is a challenging task in histopathology images.It is challenging due to the small size of objects,low contrast,touching boundaries,and complex structure of nuclei.Their segmentation and counting play an important role in cancer identification and its grading.In this study,WaveSeg-UNet,a lightweight model,is introduced to segment cancerous nuclei having touching boundaries.Residual blocks are used for feature extraction.Only one feature extractor block is used in each level of the encoder and decoder.Normally,images degrade quality and lose important information during down-sampling.To overcome this loss,discrete wavelet transform(DWT)alongside maxpooling is used in the down-sampling process.Inverse DWT is used to regenerate original images during up-sampling.In the bottleneck of the proposed model,atrous spatial channel pyramid pooling(ASCPP)is used to extract effective high-level features.The ASCPP is the modified pyramid pooling having atrous layers to increase the area of the receptive field.Spatial and channel-based attention are used to focus on the location and class of the identified objects.Finally,watershed transform is used as a post processing technique to identify and refine touching boundaries of nuclei.Nuclei are identified and counted to facilitate pathologists.The same domain of transfer learning is used to retrain the model for domain adaptability.Results of the proposed model are compared with state-of-the-art models,and it outperformed the existing studies.展开更多
To investigate the structural configuration of^(6)He and^(6)Be in a three-cluster system and to highlight dinucleon correlations,we performed a two-cluster overlap amplitude(TCOA)calculation,which is an extension of t...To investigate the structural configuration of^(6)He and^(6)Be in a three-cluster system and to highlight dinucleon correlations,we performed a two-cluster overlap amplitude(TCOA)calculation,which is an extension of the RWA formalism.The total wave functions were obtained using the generator coordinate method with microscopic cluster wave functions.Based on these wave functions,we calculated the overlap amplitudes to extract the relative motion and spatial correlations between clusters.The computed energy spectra showed reasonable agreement with the experimental data,emphasizing the effectiveness of the present framework for investigating dinucleon correlations in light nuclei.Our results revealed the presence of both dinucleon-like and cigar-like configurations in the ground states of^(6)He and^(6)Be,indicating a coexistence of compact and extended cluster structures.Furthermore,the 2_(1)^(+)state of^(6)He revealed a pronounced dineutron structure,with strong spatial correlations between the two valence neutrons.We also performed calculations for the higher-lying 2_(1)^(+)state,which showed a more spatially extended structure and provided potential references for future experimental investigations.These findings demonstrated that the TCOA method served as a powerful tool to explore cluster dynamics and dinucleon features in light,weakly bound nuclear systems.展开更多
A new detector array with a large solid angle coverage for the coincidence measurement of charged fragments was developed to study the breakup reaction mechanisms of weakly bound nuclear systems at energies around the...A new detector array with a large solid angle coverage for the coincidence measurement of charged fragments was developed to study the breakup reaction mechanisms of weakly bound nuclear systems at energies around the Coulomb barrier.The array has been used to explore the breakup reaction mechanisms of^(6,7)Li+^(209)Bi systems at E_(beam)=30,40,47 MeV,showing good performance in particle identification and complete kinematic measurements.Based on this,different breakup modes and breakup components were clearly distinguished,and some new breakup modes were discovered,such as^(7)Li→α+t breakup mode in6Li+209Bi system and^(7)Li→^(6)He+p breakup mode in^(7)Li+^(209)Bi system.This array can also be used to explore other breakup reaction mechanisms induced by weakly bound nuclei.展开更多
By combining experimental α-decay energies and half-lives, the α-particle preformation factor for nuclei around neutron magic numbers N of 126, 152, and 162 were extracted using the two-potential approach. The nucle...By combining experimental α-decay energies and half-lives, the α-particle preformation factor for nuclei around neutron magic numbers N of 126, 152, and 162 were extracted using the two-potential approach. The nuclei around the shell closure were more tightly bound than adjacent nuclei. Additionally, based on the WS4 mass model (Wang et al., Phys. Lett.B 734, 215 (2014)), we extended the two-potential approach to predict the α-decay half-lives of nuclei around N values of178 and 184 with Z of 119 and 120. We believe that our findings will serve as guidelines for future experimental studies.展开更多
The isospin asymmetry and quadrupole deformation value of drip-line nuclei are investigated using the Weizsäcker-Skyrme nuclear mass formula.We observe that for heavy nuclei at the neutron drip line,the Coulomb e...The isospin asymmetry and quadrupole deformation value of drip-line nuclei are investigated using the Weizsäcker-Skyrme nuclear mass formula.We observe that for heavy nuclei at the neutron drip line,the Coulomb energy heightened by an aug-mented charge could not be mitigated completely by symmetry energy because of isospin asymmetry saturation but is resisted complementally by strong nuclear deformation.The positions of saltation for the difference in proton numbers between two neighboring nuclei at the neutron drip line,and the isospin asymmetry of the neutron drip-line nucleus as a function of the neutron number distinctly correspond to the known magic numbers,which can serve as a reference to verify the undeter-mined neutron magic number.Through fitting of the binding energy difference between mirror nuclei(BEDbMN),a set of Coulomb energy coefficients with greater accuracy is obtained.A high-precision description of the BEDbMN is useful for accurately determining the experimentally unknown mass of the nucleus close to the proton drip line if the mass of its mirror nucleus is measured experimentally.展开更多
A coalescence model was employed to form deuterons(d),tritons(t),and helium-3(^(3)He)nuclei from a uniformly-distributed volume of protons(p)and neutrons(n).We studied the ratio N_(t)N_(p)/N_(d)^(2)of light nuclei yie...A coalescence model was employed to form deuterons(d),tritons(t),and helium-3(^(3)He)nuclei from a uniformly-distributed volume of protons(p)and neutrons(n).We studied the ratio N_(t)N_(p)/N_(d)^(2)of light nuclei yields as a function of the neutron density fluctuations.We investigated the effect of finite transverse momentum(p_(T))acceptance on the ratio,in particular,the“extrapolation factor”(f)for the ratio as a function of the p_(T)spectral shape and the magnitude of neutron density fluctuations.The nature of f was found to be monotonic in p_(T)spectra“temperature”parameter and neutron density fluctuation magnitude;variations in the latter are relatively small.We also examined f in realistic simulations using the kinematic distributions of protons measured from the heavy-ion collision data.The nature of f was found to be smooth and monotonic as a function of the beam energy.Therefore,we conclude that extrapolation from limited p_(T)ranges does not create,enhance,or reduce the local peak of the N_(t)N_(p)/N_(d)^(2)ratio in the beam energy.Our study provides a necessary benchmark for light nuclei ratios as a probe for nucleon density fluctuations,an important observation in the search for the critical point of nuclear matter.展开更多
The synthesis of superheavy nuclei remains a critical area of research in nuclear physics,with the aim of extending the periodic table and deepening our understanding of the properties of nuclei.This review provides a...The synthesis of superheavy nuclei remains a critical area of research in nuclear physics,with the aim of extending the periodic table and deepening our understanding of the properties of nuclei.This review provides a comprehensive overview of the latest advancements in superheavy nuclei synthesis,focusing on both the experimental and theoretical developments.We discuss the primary synthesis methods,including early fusion reactions with light nuclei,cold fusion reactions using lead and bismuth targets,and hot fusion reactions involving48Ca projectiles and actinide targets.In addition,we introduce the major experimental facilities and theoretical models currently employed worldwide.This review also summarizes the experimental plans and theoretical predictions for the synthesis of new superheavy elements.Furthermore,we discuss future directions,including the potential of employing heavier projectiles,radioactive beam-induced reactions,and multi-nucleon transfer reactions,which may offer new pathways for discovering unknown superheavy nuclei.展开更多
A recent paper published in Journal of the American Chemical Society by W.Zhang and co-workers reported a ground-breaking advance by establishing 209 Bi and 127 I ultra-wideline solid-state NMR(UW SSNMR)as powerful to...A recent paper published in Journal of the American Chemical Society by W.Zhang and co-workers reported a ground-breaking advance by establishing 209 Bi and 127 I ultra-wideline solid-state NMR(UW SSNMR)as powerful tools for probing bismuth and iodine ions in metal-organic frameworks(MOFs),despite the severe challenges associated with their exceptionally large quadrupolar interactions,and enabled the elucidation of key structural features that are otherwise difficult to access[1].展开更多
An accurate and simultaneous ab initio prediction for both light nuclei and nuclear matter has been a longstanding challenge in nuclear physics, due to the significant uncertainties associated with the three-nucleon f...An accurate and simultaneous ab initio prediction for both light nuclei and nuclear matter has been a longstanding challenge in nuclear physics, due to the significant uncertainties associated with the three-nucleon forces.In this Letter, we develop the relativistic quantum Monte Carlo methods for the nuclear ab initio problem, and calculate the ground-state energies of A ≤ 4 nuclei using the two-nucleon Bonn force with an unprecedented high accuracy. The present relativistic results significantly outperform the nonrelativistic results with only twonucleon forces. We demonstrate that both light nuclei and nuclear matter can be well described simultaneously in the relativistic ab initio calculations, even in the absence of three-nucleon forces, and a correlation between the properties of light A ≤ 4 nuclei and the nuclear saturation is revealed. This provides a quantitative understanding of the connection between the light nuclei and nuclear matter saturation properties.展开更多
基金National Key R&D Program of China(No.2022YFA1602302)National Natural Science Foundation of China(Nos.U2167204,12175314,and 12235020)Continuous-Support Basic Scientifc Research Project。
文摘The exploration of reaction dynamics,particularly the breakup and fusion mechanisms of proton drip-line nuclei at energies around the Coulomb barrier,is crucial in the feld of nuclear physics.This study reviews experimental investigations on the reactions induced by proton-rich nuclei,^(7)Be,^(8)B,and^(17)F,including elastic scattering and direct and fusion reactions at the near-barrier energies.In particular,we briefy introduce complete kinematic measurements of^(8)B+^(120)Sn and^(17)F+^(58)Ni at the energies of interest.Distinct reaction dynamics are observed for proton-rich nuclei compared with neutron-rich nuclei.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11375022,11575060,11505058 and 11435014
文摘The pygmy and giant dipole resonances in proton-rich nuclei 17,1817,18Ne are investigated with a fully self-consistent approach. The properties of ground states are calculated in the Skyrme Hartree–Fock with the Bardeen–Cooper–Schrieffer approximation to take into account the pairing correlation. The quasiparticle random phase approximation （QRPA） method is used to explore the properties of excited dipole states. In the calculations the SLy5 Skyrme interaction is employed. In addition to the giant dipole resonances, pygmy dipole resonances （PDR） are found to be located in the energy region below 10 MeV in both ^17,18Ne. The strength and transition density show that the low-lying states are typical PDR states. However, analyzing the QRPA amplitudes of proton and neutron 2 quasiparticle （2qp） configurations for a given low-lying state in ^17,18Ne, we find that the PDR state is less collective, more like a single 2qp excitation.
基金supported by the National Natural Science Foundation of China(No.11405025)
文摘The neutron-to-proton and3 H-to-3 He yield ratios, and the directed flows of particles dependent on a reduced rapidity, the transverse momentum per nucleon,and a reduced impact parameter are investigated for ^(28)S+^(28)Si and ^(32)S+^(28)Si systems at 50 and 400 MeV/u using an isospin-dependent quantum molecular dynamics model.The results show that these yield ratios of projectile-like fragments are approximately equal to the constituent neutron-to-proton ratio of the projectile. There are clear differences of the directed flows for isospin-related fragments neutron and proton,~3H and ~3He from ^(28)S+^(28)Si collisions.The differences in directed flows for neutrons and protons and ~3H–~3He from a proton-rich nucleus ^(28)S- induced collisions are noticeably larger than those from a stable nucleus ^(32)S- induced reactions under medium impact parameters. Thus, the yield ratios and differences in directed flows for the neutrons and protons and ~3H–~3He under medium impact parameters are proposed as possible observable items for studying isospin physics.
基金Supported partially by the Shanghai Development Foundation from Science and Technology under Grant Nos 05XD14021 and 06QA14062, the National Natural Science Foundation of China under Grant No 10328259, 10135030 and 10535010, and the Major State Basic Research and Development Programme under Grant No G200077404.
文摘We investigate the cross sections of the elastic electron or positron scat tering from 208 Pb, ^12C ^12,16O and ^28,32S by the relativistic partial-wave expansion method using the static charge density distribution from the self-consistent relativistic mean fiel model and also calculate the charge form factor for ^12＇16O and ^28,32S. The numerical results are compared with the available data. Calculations indicate that the extended charge density distributions of ^12O and ^28S have observable effects on the cross sections of the electron or positron scattering as well as the charge form factors.
基金supported by the National Natural Science Foundation of China(Grants Nos.10735010,10975072,11035001,11120101005 and 11165006)the National Major State Basic Research and Development of China(Grants Nos.2013CB834400 and 2010CB327803)+2 种基金CAS Knowledge Innovation Project(Grant No.KJCX2-SW-N02)the Research Fund of Doctoral Point(RFDP)(Grants No.20100091110028)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘We investigate the half-lives of β + /EC(electron capture) decay using the proton-neutron quasiparticle random-phase approximation(pnQRPA) with a δ-form Gamow-Teller residual interaction.Both particle-hole and particle-particle residual interactions are consistently introduced in dealing with the pnQRPA matrix equation.The sensitivity of the calculated half-lives to some physical quantities used in the calculations is examined.Calculations are performed for even-even neutron-deficient isotopes ranging from Z = 10 to Z = 76.Good agreement between experiment and theory is achieved especially for the nuclei far from stability,and the results of our calculations are discussed with comparison with other theoretical results.Predictions on the β-decay half-lives of some very neutron-deficient nuclei are also given for reference in future experiments.
基金Supported by the National Natural Science Foundation of China(12075121 and 11605089)by the Natural Science Foundation of Jiangsu Province(BK20190067 and BK20150762)。
文摘In addition to the Coulomb displacement energy,the residual differences between the binding energies of mirror nuclei(a pair of nuclei with the same mass number plus interchanged proton and neutron numbers)contribute to the shell effect via the valence scheme in this study.To this end,one linear combining type of valence nucleon number,namely,αNp+βNn,is chosen to tackle this shell correction,in which Npand Nnare the valence proton and neutron numbers with respect to the nearest shell closure,respectively.The mass differences of mirror nuclei,as the sum of the empirical Coulomb displacement energy and shell effect correction,are then used to obtain the binding energies of proton-rich nuclei through the available data of their mirror partners to explore the proton dripline of the nuclear chart.
基金Supported by the Major State Basic Research Development Program (Grant No.2007CB815000)the National Natural Science Foundation of China (Grant Nos.10525520,10735010,10875172,and J0730316)the Mao Yu-Gang Scientific Research Foundation
文摘The direct proton capture and resonance proton capture properties of stellar reactions 22Mg(p,γ)23Al and 26Si(p,γ)27P are studied by employing a mean-field potential obtained from the Skyrme-Hartree-Fock(SHF) model.Calculations with the SHF potential reproduce well the loosely-bound structure of the ground states as well as the widths of the resonant states in these nuclei.With the obtained potential we estimate the reaction rates of direct proton capture and resonance proton capture to nuclei 23Al and 27P.The effect of the 27P loosely-bound structure on the S factor of the direct proton capture is also discussed.
基金the ational Natural Science Foundation of China(12175064,U2167203)Hunan Provincial Education Department(Key project 20A290)。
文摘Multinucleon transfer reactions near the Coulomb barrier are investigated based on the improved dinuclear system(DNS)model,and the deexcitation process of primary fragments are described using the statistical model GEMINI++.The production cross sections of^(40,48)Ca+^(124)Sn and^(64)Ni+^(130)Te based on the DNS model+GEMINI++are calculated and compared with experimental data.The calculated results reproduce experimental data.The cross sections of fusion-evaporation,fragmentation,and multinucleon transfer reactions in the region are also provided in this paper.The results show that in the region,fusion-evaporation and fragmentation reactions have good results in the relatively proton-rich region,but in the extreme proton-deficient region,the MNT reaction is still promising for synthesizing proton-rich nuclei.
基金supported by the Scientific Research Foundation of Hubei University of Education for Talent Introduction(Nos.ESRC20230002 and ESRC20230007)the Research Project of Hubei Provincial Department of Education(Nos.D20233003 and B2023191)。
文摘In this study,the chemical freeze-out of hadrons,including light-and strange-flavor particles and light nuclei,produced in Au+Au collisions at the Relativistic Heavy Ion Collider(RHIC),was investigated.Using the Thermal-FIST thermodynamic statistical model,we analyzed various particle sets:those inclusive of light nuclei,those exclusive to light nuclei,and those solely comprising light nuclei.We determined the chemical freeze-out parameters at√^(S)NN=7.7–200 Ge V and four different centralities.A significant finding was the decrease in the chemical freeze-out temperature T_(ch)with light-nuclei inclusion,with an even more pronounced reduction when considering light-nuclei yields exclusively.This suggests that light-nuclei formation occurs at a later stage in the system’s evolution at RHIC energies.We present parameterized formulas that describe the energy dependence of T_(ch)and the baryon chemical potentialμ_(B) for three distinct particle sets in central Au+Au collisions at RHIC energies.Our results reveal at least three distinct T_(ch)at RHIC energies correspond to different freeze-out hypersurfaces:a light-flavor freeze-out temperature of T_L=150.2±6 Me V,a strange-flavor freeze-out temperature T_s=165.1±2.7 Me V,and a light-nuclei freeze-out temperature T_(ln)=141.7±1.4 Me V.Notably,at the Large Hadron Collider(LHC)Pb+Pb 2.76Te V,the expected lower freeze-out temperature for light nuclei was not observed;instead,the T_(ch)for light nuclei was found to be approximately 10 Me V higher than that for light-flavor hadrons.
基金supported by the National Natural Science Foundation of China(Nos.12175170 and 11675066).
文摘This paper provides a comprehensive analysis of all stages of the heavy-ion fusion evaporation reaction,aiming to enhance the understanding of the entire process and identify the influencing factors in calculating the evaporation residue cross-section.By focusing on the synthesis of superheavy nuclei with Z=114,we discuss the capture cross-section,fusion probability,and survival probability of the ^(48)Ca+^(244)Pu reaction and compare them with those of the 40Ar+248Cm reaction.Moreover,a systematic study examined the evaporation residue cross-sections for the synthesis of superheavy nuclei with Z=112-116 using ^(40)Ar as the projectile nucleus.The results indicate that utilizing ^(40)Ar as the projectile nucleus for synthesizing isotopes with Z=114 offers advantages such as lower incident energy and reduced experimental costs.Furthermore,using ^(40)Ar as the projectile nucleus enables the synthesis of a new key isotope,285115,thereby facilitating its identification.
基金supported by the National Natural Science Foundation of China(Nos.12375244 and 12135009)the Hunan Provincial Innovation Foundation for Postgraduate(Nos.CX20210007 and CX20230008)。
文摘In this study,we explore the impact of state-of-the-art laser fields on theαdecay half-life of deformed ground-state odd-A nuclei within the proton number range of 52–107.The calculations show that the presence of a laser field modulates theαdecay half-life by altering theαdecay penetration probability within a limited range.Moreover,the variance in the penetration probability rate of change between even–odd and odd–even nuclei is investigated.Furthermore,we investigate the rate of change of the penetration probability for the same parent nucleus with different neutron numbers,based on the characteristics of the odd-A nucleus.We found that the influence of the laser field on the penetration probability is determined by both the shell effect and odd–even staggering.This research contributes to the understanding of nuanced interactions between laser fields and nuclear decay processes.Therefore,valuable insights for future experiments in laser–nuclear physics are attainable using this study.
文摘Nuclei segmentation is a challenging task in histopathology images.It is challenging due to the small size of objects,low contrast,touching boundaries,and complex structure of nuclei.Their segmentation and counting play an important role in cancer identification and its grading.In this study,WaveSeg-UNet,a lightweight model,is introduced to segment cancerous nuclei having touching boundaries.Residual blocks are used for feature extraction.Only one feature extractor block is used in each level of the encoder and decoder.Normally,images degrade quality and lose important information during down-sampling.To overcome this loss,discrete wavelet transform(DWT)alongside maxpooling is used in the down-sampling process.Inverse DWT is used to regenerate original images during up-sampling.In the bottleneck of the proposed model,atrous spatial channel pyramid pooling(ASCPP)is used to extract effective high-level features.The ASCPP is the modified pyramid pooling having atrous layers to increase the area of the receptive field.Spatial and channel-based attention are used to focus on the location and class of the identified objects.Finally,watershed transform is used as a post processing technique to identify and refine touching boundaries of nuclei.Nuclei are identified and counted to facilitate pathologists.The same domain of transfer learning is used to retrain the model for domain adaptability.Results of the proposed model are compared with state-of-the-art models,and it outperformed the existing studies.
基金supported by the National Key R&D Program of China(Nos.2023YFA1606701 and 2022YFA1602402)the National Natural Science Foundation of China(Nos.12175042,11890710,11890714,12047514,12147101,and 12347106)+1 种基金Guangdong Major Project of Basic and Applied Basic Research(No.2020B0301030008)the 111 Project。
文摘To investigate the structural configuration of^(6)He and^(6)Be in a three-cluster system and to highlight dinucleon correlations,we performed a two-cluster overlap amplitude(TCOA)calculation,which is an extension of the RWA formalism.The total wave functions were obtained using the generator coordinate method with microscopic cluster wave functions.Based on these wave functions,we calculated the overlap amplitudes to extract the relative motion and spatial correlations between clusters.The computed energy spectra showed reasonable agreement with the experimental data,emphasizing the effectiveness of the present framework for investigating dinucleon correlations in light nuclei.Our results revealed the presence of both dinucleon-like and cigar-like configurations in the ground states of^(6)He and^(6)Be,indicating a coexistence of compact and extended cluster structures.Furthermore,the 2_(1)^(+)state of^(6)He revealed a pronounced dineutron structure,with strong spatial correlations between the two valence neutrons.We also performed calculations for the higher-lying 2_(1)^(+)state,which showed a more spatially extended structure and provided potential references for future experimental investigations.These findings demonstrated that the TCOA method served as a powerful tool to explore cluster dynamics and dinucleon features in light,weakly bound nuclear systems.
基金supported by the National Key R&D Program of China(Nos.2022YFA1602302 and 2023YFA1606402)the National Natural Science Foundation of China(Nos.U2167204,12175314,12235020 and 12275360)+2 种基金the Continuous-Support Basic Scientific Research Projectthe"111 Center"the China Scholarship Council(CSC)。
文摘A new detector array with a large solid angle coverage for the coincidence measurement of charged fragments was developed to study the breakup reaction mechanisms of weakly bound nuclear systems at energies around the Coulomb barrier.The array has been used to explore the breakup reaction mechanisms of^(6,7)Li+^(209)Bi systems at E_(beam)=30,40,47 MeV,showing good performance in particle identification and complete kinematic measurements.Based on this,different breakup modes and breakup components were clearly distinguished,and some new breakup modes were discovered,such as^(7)Li→α+t breakup mode in6Li+209Bi system and^(7)Li→^(6)He+p breakup mode in^(7)Li+^(209)Bi system.This array can also be used to explore other breakup reaction mechanisms induced by weakly bound nuclei.
基金supported in part by the National Natural Science Foundation of China(Nos.12175100 and 11975132)Construct Program of the Key Discipline in Hunan Province,Research Foundation of Education Bureau of Hunan Province,China(Nos.21B0402,18A237 and 22A0305)+3 种基金Natural Science Foundation of Hunan Province,China(No.2018JJ2321)Innovation Group of Nuclear and Particle Physics in USC,Shandong Province Natural Science Foundation,China(No.ZR2022JQ04)Opening Project of Cooperative Innovation Center for Nuclear Fuel Cycle Technology and Equipment,University of South China(No.2019KFZ10)Hunan Provincial Innovation Foundation for Postgraduate(No.CX20230962).
文摘By combining experimental α-decay energies and half-lives, the α-particle preformation factor for nuclei around neutron magic numbers N of 126, 152, and 162 were extracted using the two-potential approach. The nuclei around the shell closure were more tightly bound than adjacent nuclei. Additionally, based on the WS4 mass model (Wang et al., Phys. Lett.B 734, 215 (2014)), we extended the two-potential approach to predict the α-decay half-lives of nuclei around N values of178 and 184 with Z of 119 and 120. We believe that our findings will serve as guidelines for future experimental studies.
基金supported by the Ministry of Science and Technology of China(No.2022YFE0103400)Natural Science Foundation of Guangxi Province(No.2021GXNSFAA196052)National Natural Science Foundation of China(No.11965004).
文摘The isospin asymmetry and quadrupole deformation value of drip-line nuclei are investigated using the Weizsäcker-Skyrme nuclear mass formula.We observe that for heavy nuclei at the neutron drip line,the Coulomb energy heightened by an aug-mented charge could not be mitigated completely by symmetry energy because of isospin asymmetry saturation but is resisted complementally by strong nuclear deformation.The positions of saltation for the difference in proton numbers between two neighboring nuclei at the neutron drip line,and the isospin asymmetry of the neutron drip-line nucleus as a function of the neutron number distinctly correspond to the known magic numbers,which can serve as a reference to verify the undeter-mined neutron magic number.Through fitting of the binding energy difference between mirror nuclei(BEDbMN),a set of Coulomb energy coefficients with greater accuracy is obtained.A high-precision description of the BEDbMN is useful for accurately determining the experimentally unknown mass of the nucleus close to the proton drip line if the mass of its mirror nucleus is measured experimentally.
基金supported in part by the U.S.Department of Energy(No.DE-SC0012910)National Nature Science Foundation of China(Nos.12035006 and 12075085)the Ministry of Science and Technology of China(No.2020YFE020200)。
文摘A coalescence model was employed to form deuterons(d),tritons(t),and helium-3(^(3)He)nuclei from a uniformly-distributed volume of protons(p)and neutrons(n).We studied the ratio N_(t)N_(p)/N_(d)^(2)of light nuclei yields as a function of the neutron density fluctuations.We investigated the effect of finite transverse momentum(p_(T))acceptance on the ratio,in particular,the“extrapolation factor”(f)for the ratio as a function of the p_(T)spectral shape and the magnitude of neutron density fluctuations.The nature of f was found to be monotonic in p_(T)spectra“temperature”parameter and neutron density fluctuation magnitude;variations in the latter are relatively small.We also examined f in realistic simulations using the kinematic distributions of protons measured from the heavy-ion collision data.The nature of f was found to be smooth and monotonic as a function of the beam energy.Therefore,we conclude that extrapolation from limited p_(T)ranges does not create,enhance,or reduce the local peak of the N_(t)N_(p)/N_(d)^(2)ratio in the beam energy.Our study provides a necessary benchmark for light nuclei ratios as a probe for nucleon density fluctuations,an important observation in the search for the critical point of nuclear matter.
基金supported by the National Key R&D Program of China(No.2023YFA1606401)the National Key R&D Program of China(Nos.2023YFA1606500,2023YFA1606501,2023YFA1606504)+3 种基金the National Natural Science Foundation of China(Nos.12135004,11635003,11961141004,12375118,and 12435008)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB34010000)the Major State Basic Research Development Program of China(2023YFA1606503)the CAS Strategic Priority Research Program(XDB34010000)。
文摘The synthesis of superheavy nuclei remains a critical area of research in nuclear physics,with the aim of extending the periodic table and deepening our understanding of the properties of nuclei.This review provides a comprehensive overview of the latest advancements in superheavy nuclei synthesis,focusing on both the experimental and theoretical developments.We discuss the primary synthesis methods,including early fusion reactions with light nuclei,cold fusion reactions using lead and bismuth targets,and hot fusion reactions involving48Ca projectiles and actinide targets.In addition,we introduce the major experimental facilities and theoretical models currently employed worldwide.This review also summarizes the experimental plans and theoretical predictions for the synthesis of new superheavy elements.Furthermore,we discuss future directions,including the potential of employing heavier projectiles,radioactive beam-induced reactions,and multi-nucleon transfer reactions,which may offer new pathways for discovering unknown superheavy nuclei.
基金supported by the National Natural Science Foundation of China(Grants 22472075 and 22272075).
文摘A recent paper published in Journal of the American Chemical Society by W.Zhang and co-workers reported a ground-breaking advance by establishing 209 Bi and 127 I ultra-wideline solid-state NMR(UW SSNMR)as powerful tools for probing bismuth and iodine ions in metal-organic frameworks(MOFs),despite the severe challenges associated with their exceptionally large quadrupolar interactions,and enabled the elucidation of key structural features that are otherwise difficult to access[1].
基金supported in part by the National Natural Science Foundation of China (Grant Nos. 12141501, 123B2080, 12435006, 12475117, and 11935003)the National Key Laboratory of Neutron Science and Technology (Grant No. NST202401016)+2 种基金the National Key R&D Program of China (Grant No. 2024YFE0109803)the High-performance Computing Platform of Peking Universitythe funding support from the State Key Laboratory of Nuclear Physics and Technology, Peking University (Grant No. NPT2023ZX03)。
文摘An accurate and simultaneous ab initio prediction for both light nuclei and nuclear matter has been a longstanding challenge in nuclear physics, due to the significant uncertainties associated with the three-nucleon forces.In this Letter, we develop the relativistic quantum Monte Carlo methods for the nuclear ab initio problem, and calculate the ground-state energies of A ≤ 4 nuclei using the two-nucleon Bonn force with an unprecedented high accuracy. The present relativistic results significantly outperform the nonrelativistic results with only twonucleon forces. We demonstrate that both light nuclei and nuclear matter can be well described simultaneously in the relativistic ab initio calculations, even in the absence of three-nucleon forces, and a correlation between the properties of light A ≤ 4 nuclei and the nuclear saturation is revealed. This provides a quantitative understanding of the connection between the light nuclei and nuclear matter saturation properties.
