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
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 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
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
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
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
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
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
We calculate the binding energies of Ni, Cu, Xe, Cs, Pt, Au, Np, Pu isotope chains using two interaction parameter sets NL-3 and NL-Z, and compared the relative errors of the even-even nuclei with those of odd-even nu...We calculate the binding energies of Ni, Cu, Xe, Cs, Pt, Au, Np, Pu isotope chains using two interaction parameter sets NL-3 and NL-Z, and compared the relative errors of the even-even nuclei with those of odd-even nuclei and odd-odd nuclei. We find that the errors of binding energy of odd-even and odd-odd nuclei are not bigger than the one of even-even nuclei. The result shows that comparing with even-even nuclei, there is no systematic error and approximation in the calculations of the binding energy of odd-even and odd-odd nuclei with relativistic mean-field theory. In addition, the result is explained theoretically.展开更多
[Objective] The experiment aimed to study an efficient method of Nuclei extraction of cotton and provided technical support for constructing large-insert genomic library and sequencing complete genome. [Method] The co...[Objective] The experiment aimed to study an efficient method of Nuclei extraction of cotton and provided technical support for constructing large-insert genomic library and sequencing complete genome. [Method] The cotton cotyledons germinated in dark moisture chamber for one week were chopped with a sharp sterile scalpel in a Petri dish which contained ice-cold nucleus isolation buffer (10 mmol/L MgSO4, 5 mmol/L KCl, 0.5 mmol/L HEPES, 1 mg/ml DTT, 0.25% Triton X-100 and 2% PVP40), then the nuclei were collected after selected through 100, 50 and 30 μm nylon meshes and centrifugation. Meanwhile, the tender leaves and cotyledons with different germination time in dark were treated by grinding method and sharp scalpel method. [Result] The chopping with a sharp scalpel method was very simple and rapid, which did not need grind and mercaptoethanol treatment and the successful extraction rate was 100%.[Conclusion] An efficient method of nuclei extraction of cotton with simple, high efficiency, rapid reaction and poison free were established.展开更多
Heavy-ion collisions are powerful tools for studying hypernuclear physics.We develop a dynamical coalescence model coupled with an ART model(version1.0) to study the production rates of light nuclear clusters and hype...Heavy-ion collisions are powerful tools for studying hypernuclear physics.We develop a dynamical coalescence model coupled with an ART model(version1.0) to study the production rates of light nuclear clusters and hypernuclei in heavy-ion reactions,for instance,the deuteron(d),triton(t),helium(~3He),and hypertriton(_A^3H)in minimum bias(0-80%centrality)~6Li+^(12)C reactions at beam energy of 3.5A GeV.The penalty factor for light clusters is extracted from the yields,and the distributions of 0 angle of particles,which provide direct suggesetions about the location of particle detectors in the near future facility-High Intensity heavy-ion Accelerator Facility(HIAF) are investigated.Our calculation demonstrates that HIAF is suitable for studying hypernuclear physics.展开更多
The reactions of ^16O＋^204pb, ^82Se＋^138Ba and ^96Zr＋^124Sn lead to the same compound nucleus ^220Th. In terms of the assumption that the surviving probability is independent of entrance channel, we have extracted ...The reactions of ^16O＋^204pb, ^82Se＋^138Ba and ^96Zr＋^124Sn lead to the same compound nucleus ^220Th. In terms of the assumption that the surviving probability is independent of entrance channel, we have extracted the fusion hindrance factor from the evaporation residue cross sections for the reactions of ^82Se＋^138 Ba and ^96Zr＋^124Sn and compared with the results calculated using a two-parameter Smoluchowski equation. The theoretical predictions are basically in agreement with the experimental data. It is found that the probability of forming a compact ^220Th is less than 10% for the reactions considered. For the systems more massive than ^220Th, fusion should be much more strongly suppressed due to the competition of quasifission with complete fusion. Understanding of this inhibition is essential to forming new superheavy nuclei.展开更多
In this study,we revisit the previous mass relations of mirror nuclei by considering 1/N-and 1/Z-dependent terms and the shell effect across a shell.The root-mean-squared deviation is 66 keV for 116 nuclei with neutro...In this study,we revisit the previous mass relations of mirror nuclei by considering 1/N-and 1/Z-dependent terms and the shell effect across a shell.The root-mean-squared deviation is 66 keV for 116 nuclei with neutron number N≥10,as com-pared with experimental data compiled in the AME2020 database.The predicted mass excesses of 173 proton-rich nuclei,including 98 unknown nuclei,are tabulated in the Supplemental Material herein with competitive accuracy.展开更多
Radioactivity of nuclei in a centrifugal force field of an ultracentrifuge is considered for heavy radioactive nuclei, i.e., for the same nuclei, but with a significant virtual mass thousands of times larger than the ...Radioactivity of nuclei in a centrifugal force field of an ultracentrifuge is considered for heavy radioactive nuclei, i.e., for the same nuclei, but with a significant virtual mass thousands of times larger than the actual mass and is characterized by an angular momentum. As the nucleus leaves the centrifugal force field, the virtual mass disappears, but the spin number appears and/or changes. The role of centrifugal and gravitational forces in radioactive decay of nuclei is studied. According to the terminology of western researchers, such a virtual mass state is called the dynamic gravitation which is more adequate. The oscillator and possible changes in the nucleus state are considered under conditions of dynamic gravitation and taking into account features of atomic nucleus physics. To a first approximation, the drop model of the nucleus was used, in which shape fluctuations have much in common with geophysical and astrophysical analogues. Shape fluctuations of analogues strongly depend on the gravitational force g defined by their mass (or nucleus mass). Experiments were performed by radiometric measurements of transbaikalian uranium ore (1.5 g) with known composition in a centrifuge at various rotation rates or gravitational forces g. The existence of characteristic times or the effect of rotation frequencies (i.e., g) on atomic nuclei, which, along with the nucleus type itself, controls the nucleus response to perturbation (stability increase or decay), is found statistically significant.展开更多
According to the new proton and neutron nuclear picture described earlier, the structure of the nucleus will also be given a new interpretation. The role of the delocalized electrons detached from the outer shell of n...According to the new proton and neutron nuclear picture described earlier, the structure of the nucleus will also be given a new interpretation. The role of the delocalized electrons detached from the outer shell of neutrons is shown in the binding energy value of the nucleus. It is pointed out that the spatial arrangement of nucleons is also very important for the stability of nuclei according to the analyzation of the magic numbers from a geometric point of view.展开更多
Knowledge of the statistical characteristics of inversions and their effects on aerosols under different large-scale synoptic circulations is important for studying and modeling the diffusion of pollutants in the boun...Knowledge of the statistical characteristics of inversions and their effects on aerosols under different large-scale synoptic circulations is important for studying and modeling the diffusion of pollutants in the boundary layer. Based on results gen- erated using the self-organizing map （SOM） weather classification method, this study compares the statistical characteristics of surface-based inversions （SBIs） and elevated inversions （EIs）, and quantitatively evaluates the effect of SBIs on aerosol condensation nuclei （CN） concentrations and the relationship between temperature gradients and aerosols for six prevailing synoptic patterns over the the Southern Great Plains （SGP） site during 2001-10. Large-scale synoptic patterns strongly influ- ence the statistical characteristics of inversions and the accumulation of aerosols in the low-level atmosphere. The activity, frequency, intensity, and vertical distribution of inversions are significantly different among these synoptic patterns. The verti- cal distribution of inversions varies diurnally and is significantly different among the different synoptic patterns. Anticyclonic patterns affect the accumulation of aerosols near the ground more strongly than cyclonic patterns. Mean aerosol CN con- centrations increase during SBIs compared to no inversion cases by 16.1%, 22.6%, 24.5%, 58.7%, 29.8% and 23.7% for the six synoptic patterns. This study confirms that there is a positive correlation between temperature gradients and aerosol CN concentrations near the ground at night under similar large-scale synoptic patterns. The relationship is different for different synoptic patterns and can be described by linear functions. These findings suggest that large-scale synoptic patterns change the static stability of the atmosphere and inversions in the lower atmosphere, thereby influencing the diffusion of aerosols near the ground.展开更多
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 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 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 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 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 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(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 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.
基金The project supported by National Natural Science Foundation of China under Grant No. 10475026 （2004）
文摘We calculate the binding energies of Ni, Cu, Xe, Cs, Pt, Au, Np, Pu isotope chains using two interaction parameter sets NL-3 and NL-Z, and compared the relative errors of the even-even nuclei with those of odd-even nuclei and odd-odd nuclei. We find that the errors of binding energy of odd-even and odd-odd nuclei are not bigger than the one of even-even nuclei. The result shows that comparing with even-even nuclei, there is no systematic error and approximation in the calculations of the binding energy of odd-even and odd-odd nuclei with relativistic mean-field theory. In addition, the result is explained theoretically.
基金Supported by the National Natural Science Foundation of China(No.30170501)the State of New Varieties of GMO Cultivation Major Projects (No.2008ZX08005-003)the National High-tech Research Development Plan (No.2003AA207051)~~
文摘[Objective] The experiment aimed to study an efficient method of Nuclei extraction of cotton and provided technical support for constructing large-insert genomic library and sequencing complete genome. [Method] The cotton cotyledons germinated in dark moisture chamber for one week were chopped with a sharp sterile scalpel in a Petri dish which contained ice-cold nucleus isolation buffer (10 mmol/L MgSO4, 5 mmol/L KCl, 0.5 mmol/L HEPES, 1 mg/ml DTT, 0.25% Triton X-100 and 2% PVP40), then the nuclei were collected after selected through 100, 50 and 30 μm nylon meshes and centrifugation. Meanwhile, the tender leaves and cotyledons with different germination time in dark were treated by grinding method and sharp scalpel method. [Result] The chopping with a sharp scalpel method was very simple and rapid, which did not need grind and mercaptoethanol treatment and the successful extraction rate was 100%.[Conclusion] An efficient method of nuclei extraction of cotton with simple, high efficiency, rapid reaction and poison free were established.
基金supported in part by the Major State Basic Research Development Program in China(Nos.2014CB845401 and2015CB856904)the National Natural Science Foundation of China(Nos.11421505,11520101004,11275250,11322547 and U1232206)Key Program of CAS for the Frontier Science(No.QYZDJ-SSW-SLH002)
文摘Heavy-ion collisions are powerful tools for studying hypernuclear physics.We develop a dynamical coalescence model coupled with an ART model(version1.0) to study the production rates of light nuclear clusters and hypernuclei in heavy-ion reactions,for instance,the deuteron(d),triton(t),helium(~3He),and hypertriton(_A^3H)in minimum bias(0-80%centrality)~6Li+^(12)C reactions at beam energy of 3.5A GeV.The penalty factor for light clusters is extracted from the yields,and the distributions of 0 angle of particles,which provide direct suggesetions about the location of particle detectors in the near future facility-High Intensity heavy-ion Accelerator Facility(HIAF) are investigated.Our calculation demonstrates that HIAF is suitable for studying hypernuclear physics.
基金Supported by the National Natural Science Foundation of China under Grants Nos 10235020 and 10235030.
文摘The reactions of ^16O＋^204pb, ^82Se＋^138Ba and ^96Zr＋^124Sn lead to the same compound nucleus ^220Th. In terms of the assumption that the surviving probability is independent of entrance channel, we have extracted the fusion hindrance factor from the evaporation residue cross sections for the reactions of ^82Se＋^138 Ba and ^96Zr＋^124Sn and compared with the results calculated using a two-parameter Smoluchowski equation. The theoretical predictions are basically in agreement with the experimental data. It is found that the probability of forming a compact ^220Th is less than 10% for the reactions considered. For the systems more massive than ^220Th, fusion should be much more strongly suppressed due to the competition of quasifission with complete fusion. Understanding of this inhibition is essential to forming new superheavy nuclei.
基金supported by the National Natural Science Foundation of China(No.11905130).
文摘In this study,we revisit the previous mass relations of mirror nuclei by considering 1/N-and 1/Z-dependent terms and the shell effect across a shell.The root-mean-squared deviation is 66 keV for 116 nuclei with neutron number N≥10,as com-pared with experimental data compiled in the AME2020 database.The predicted mass excesses of 173 proton-rich nuclei,including 98 unknown nuclei,are tabulated in the Supplemental Material herein with competitive accuracy.
文摘Radioactivity of nuclei in a centrifugal force field of an ultracentrifuge is considered for heavy radioactive nuclei, i.e., for the same nuclei, but with a significant virtual mass thousands of times larger than the actual mass and is characterized by an angular momentum. As the nucleus leaves the centrifugal force field, the virtual mass disappears, but the spin number appears and/or changes. The role of centrifugal and gravitational forces in radioactive decay of nuclei is studied. According to the terminology of western researchers, such a virtual mass state is called the dynamic gravitation which is more adequate. The oscillator and possible changes in the nucleus state are considered under conditions of dynamic gravitation and taking into account features of atomic nucleus physics. To a first approximation, the drop model of the nucleus was used, in which shape fluctuations have much in common with geophysical and astrophysical analogues. Shape fluctuations of analogues strongly depend on the gravitational force g defined by their mass (or nucleus mass). Experiments were performed by radiometric measurements of transbaikalian uranium ore (1.5 g) with known composition in a centrifuge at various rotation rates or gravitational forces g. The existence of characteristic times or the effect of rotation frequencies (i.e., g) on atomic nuclei, which, along with the nucleus type itself, controls the nucleus response to perturbation (stability increase or decay), is found statistically significant.
文摘According to the new proton and neutron nuclear picture described earlier, the structure of the nucleus will also be given a new interpretation. The role of the delocalized electrons detached from the outer shell of neutrons is shown in the binding energy value of the nucleus. It is pointed out that the spatial arrangement of nucleons is also very important for the stability of nuclei according to the analyzation of the magic numbers from a geometric point of view.
基金sponsored by the U.S. Department of Energy (DOE)supported by the Ministry of Science and Technology of China (Grant Nos. 2010CB950804 and 2013CB955801)+1 种基金the "Strategic Priority Research Program" of the Chinese Academy of Sciences (Grant No. XDA05100300)the National Natural Science Foundation of China (Grant No. 41305011)
文摘Knowledge of the statistical characteristics of inversions and their effects on aerosols under different large-scale synoptic circulations is important for studying and modeling the diffusion of pollutants in the boundary layer. Based on results gen- erated using the self-organizing map （SOM） weather classification method, this study compares the statistical characteristics of surface-based inversions （SBIs） and elevated inversions （EIs）, and quantitatively evaluates the effect of SBIs on aerosol condensation nuclei （CN） concentrations and the relationship between temperature gradients and aerosols for six prevailing synoptic patterns over the the Southern Great Plains （SGP） site during 2001-10. Large-scale synoptic patterns strongly influ- ence the statistical characteristics of inversions and the accumulation of aerosols in the low-level atmosphere. The activity, frequency, intensity, and vertical distribution of inversions are significantly different among these synoptic patterns. The verti- cal distribution of inversions varies diurnally and is significantly different among the different synoptic patterns. Anticyclonic patterns affect the accumulation of aerosols near the ground more strongly than cyclonic patterns. Mean aerosol CN con- centrations increase during SBIs compared to no inversion cases by 16.1%, 22.6%, 24.5%, 58.7%, 29.8% and 23.7% for the six synoptic patterns. This study confirms that there is a positive correlation between temperature gradients and aerosol CN concentrations near the ground at night under similar large-scale synoptic patterns. The relationship is different for different synoptic patterns and can be described by linear functions. These findings suggest that large-scale synoptic patterns change the static stability of the atmosphere and inversions in the lower atmosphere, thereby influencing the diffusion of aerosols near the ground.
