Ideas, solely related on the nuclear shell model, fail to give an interpretation of the experimental central role of 54Xe in the asymmetric fission of actinides. The same is true for the β-delayed fission of ...Ideas, solely related on the nuclear shell model, fail to give an interpretation of the experimental central role of 54Xe in the asymmetric fission of actinides. The same is true for the β-delayed fission of 180Tl to 80Kr and 100Ru. The representation of the natural isotopes, in the Z-Neutron Excess plane, suggests the importance of the of the Neutron Excess evolution mode in the fragments of the asymmetric actinide fission and in the fragments of the β-delayed fission of 180Tl. The evolution mode of the Neutron Excess, hinged at Kr and Xe, is directed by the 50 and 82 neutron magic numbers. The present isotope representation offers a frame for the interpretation of the post fission evaporation of neutrons, higher for the AL compared to the AH fragments, a tenet in nuclear fission. Further enlightened is the functional meaning of the 50 proton magic number, marking the start of the yield rise of the AH fragments in actinide fission.展开更多
In this paper, we present direct mass measurements of neutron-rich S6Kr projectile fragments conducted at the HIRFL-CSR facility in Lanzhou by employing the Isochronous Mass Spectrometry （IMS） method. The new mass e...In this paper, we present direct mass measurements of neutron-rich S6Kr projectile fragments conducted at the HIRFL-CSR facility in Lanzhou by employing the Isochronous Mass Spectrometry （IMS） method. The new mass excesses of ^52-54Sc nuclides are determined to be -40492（82）, -38928（114）, -34654（540） keV, which show a significant increase of binding energy compared to the reported ones in the Atomic Mass Evaluation 2012 （AME12）. In particular, ^53Sc and ^54sc are more bound by 0.8 MeV and 1.0 MeV, respectively. The behavior of the two neutron separation energy with neutron numbers indicates a strong sub-shell closure at neutron number N=32 in Sc isotopes.展开更多
In the framework of Strutinsky＇s approach, we calculated the shell and the residual pairing correction energies for 5569 even-even nuclei in the range 72 ≤ Z ≤ 282 and 96≤N ≤ 540. Quasi-magic numbers and deformed...In the framework of Strutinsky＇s approach, we calculated the shell and the residual pairing correction energies for 5569 even-even nuclei in the range 72 ≤ Z ≤ 282 and 96≤N ≤ 540. Quasi-magic numbers and deformed islands of stability that reside in a range defined by Green＇s formula and the two-neutrons drip line are introduced. We present 36 quasi-magic proton and 53 quasi-magic neutron magic numbers that contribute to the formation of 133 deformed islands of stability along the N-Z space. The quasi-magic proton and neutron magic numbers volatile as the mass number increases and other magic numbers take over. Consequently, the deformed islands of stability fail to exhibit a pattern along the search space covered.展开更多
The metallic softness parameterαr 0 determines the structure of the cluster and governs the rule of magic numbers. Using molecular dynamic method, the stable structures and magic numbers are determined for the cluste...The metallic softness parameterαr 0 determines the structure of the cluster and governs the rule of magic numbers. Using molecular dynamic method, the stable structures and magic numbers are determined for the clusters consisting of 13 up to 147 atoms in medium range Morse potentials, which is suitable for most of metals. As the number of atoms constituting the cluster increases, the stable structures undergo transition from face-centered (FC) to edge-centered (EC) structures. The magic number take ones of FC series before transition and take ones of EC series after that. The transition point from FC to EC structures depends on the value of softness parameter.展开更多
The identification of highly abundant,“magic”spe-cies in the mass spectra of clusters have proven to be valuable in nanoscience,leading to the discovery of new stable species such as fullerenes and the elec-tronic s...The identification of highly abundant,“magic”spe-cies in the mass spectra of clusters have proven to be valuable in nanoscience,leading to the discovery of new stable species such as fullerenes and the elec-tronic shell structures of metallic clusters.展开更多
A molecular dynamics simulation study has been performed for a large sys- tem consisting of 100000 liquid metal Al atoms to investigate the formation and magic number characteristics of the cluster configurations form...A molecular dynamics simulation study has been performed for a large sys- tem consisting of 100000 liquid metal Al atoms to investigate the formation and magic number characteristics of the cluster configurations formed during the rapid solidification processes. The cluster-type index method (CTIM) has been adopted to describe various types of cluster configurations. The results indicate that the icosahedral clusters (12 0 12 0) and their combinations play the most important role in the microstructure transitions during solidification processes; for the cluster configurations of different levels formed by various combinations with differing numbers of basic clusters, their size distributions possess ob- vious magic number sequence which is in turn as 13(13), 19(21), 26-28(27), 32-33(32), 39-40, 43-44, 48…, (those in bracket are the corresponding value in liquid state); the magic numbers correspond to the peak value positions of the cluster numbers for corre- sponding level formed with various combinations by 1, 2, 3, 4, 5, 6, 7, …basic clusters, respectively. This magic number sequence is in good agreement with the experimental results obtained by Harris et al. At the same time, this simulation study also gives a scien- tific and reasonable explanation to these experimental results.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
对于图G(V,E),若存在正整数k(1≤k≤|G|+|E|)和映射f:V(G)∪Ε(G)→{1,2,…,k},使得对任意两点u,v∈V(G),有S(u)=S(v),其中S(u)=f(u)+∑_(uw∈E(G))f(uw),则称f为G的点魔幻全染色,且称χVMTC(G)=max{k|k-VMTC of G}为点魔幻全色数.在已...对于图G(V,E),若存在正整数k(1≤k≤|G|+|E|)和映射f:V(G)∪Ε(G)→{1,2,…,k},使得对任意两点u,v∈V(G),有S(u)=S(v),其中S(u)=f(u)+∑_(uw∈E(G))f(uw),则称f为G的点魔幻全染色,且称χVMTC(G)=max{k|k-VMTC of G}为点魔幻全色数.在已有的点魔幻标号和点可区别染色研究基础之上,结合实际问题提出了点魔幻全染色(VMTC),设计了一种新型的点魔幻全染色算法,该算法使用迭代寻优的方式对随机图进行了研究,通过实验结果分析,总结得到了若干定理并给出证明.展开更多
The production mechanism of Cu/Cl binary clusters were investigated by laser vaporization of CuCl, CuCl2, CuCl2·2H2O by time-of-flight mass spectrometry. We found that lager cluster size can be detected by using ...The production mechanism of Cu/Cl binary clusters were investigated by laser vaporization of CuCl, CuCl2, CuCl2·2H2O by time-of-flight mass spectrometry. We found that lager cluster size can be detected by using CuCl2·2H2O solid pellets than CuCl2 and CuCl. Only Cu+(CuCl)n, (CuCl)n, n <8 were observed when 532 um laser vaporized the CuCl. We also found almost the same cluster using CuCl2 and CuCl2·2H2O in the same mass range, deficit Cu clusters were dominated for clusters with more than five Cu atoms when using CuCl2, CuCl2·2H2O compounds. The relation of relative intensity In2:/In-1In+1 vs. different size of clusters were almost the same using different compounds above. (CuCl)3+.(CuCl)+6 ions in (CuCl)+n series, and Cu6Cl+5 in Cu(CuCl)+n series have special stability. The magic number observed above are different from those of alkali halide (MX) clusters, hexagonal structures were proposed for the above magic number clusters.展开更多
文摘Ideas, solely related on the nuclear shell model, fail to give an interpretation of the experimental central role of 54Xe in the asymmetric fission of actinides. The same is true for the β-delayed fission of 180Tl to 80Kr and 100Ru. The representation of the natural isotopes, in the Z-Neutron Excess plane, suggests the importance of the of the Neutron Excess evolution mode in the fragments of the asymmetric actinide fission and in the fragments of the β-delayed fission of 180Tl. The evolution mode of the Neutron Excess, hinged at Kr and Xe, is directed by the 50 and 82 neutron magic numbers. The present isotope representation offers a frame for the interpretation of the post fission evaporation of neutrons, higher for the AL compared to the AH fragments, a tenet in nuclear fission. Further enlightened is the functional meaning of the 50 proton magic number, marking the start of the yield rise of the AH fragments in actinide fission.
基金Supported by 973 Program of China(2013CB834401)the NSFC(U1232208,U1432125,11205205,11035007)the Helmholtz-CAS Joint Research Group(HCJRG-108)
文摘In this paper, we present direct mass measurements of neutron-rich S6Kr projectile fragments conducted at the HIRFL-CSR facility in Lanzhou by employing the Isochronous Mass Spectrometry （IMS） method. The new mass excesses of ^52-54Sc nuclides are determined to be -40492（82）, -38928（114）, -34654（540） keV, which show a significant increase of binding energy compared to the reported ones in the Atomic Mass Evaluation 2012 （AME12）. In particular, ^53Sc and ^54sc are more bound by 0.8 MeV and 1.0 MeV, respectively. The behavior of the two neutron separation energy with neutron numbers indicates a strong sub-shell closure at neutron number N=32 in Sc isotopes.
文摘In the framework of Strutinsky＇s approach, we calculated the shell and the residual pairing correction energies for 5569 even-even nuclei in the range 72 ≤ Z ≤ 282 and 96≤N ≤ 540. Quasi-magic numbers and deformed islands of stability that reside in a range defined by Green＇s formula and the two-neutrons drip line are introduced. We present 36 quasi-magic proton and 53 quasi-magic neutron magic numbers that contribute to the formation of 133 deformed islands of stability along the N-Z space. The quasi-magic proton and neutron magic numbers volatile as the mass number increases and other magic numbers take over. Consequently, the deformed islands of stability fail to exhibit a pattern along the search space covered.
基金Supported by the National Natural Science Foundation of China(196 740 42 198340 70 ) Science and Technology Program of Natio
文摘The metallic softness parameterαr 0 determines the structure of the cluster and governs the rule of magic numbers. Using molecular dynamic method, the stable structures and magic numbers are determined for the clusters consisting of 13 up to 147 atoms in medium range Morse potentials, which is suitable for most of metals. As the number of atoms constituting the cluster increases, the stable structures undergo transition from face-centered (FC) to edge-centered (EC) structures. The magic number take ones of FC series before transition and take ones of EC series after that. The transition point from FC to EC structures depends on the value of softness parameter.
基金The financial support for this work was provided by the National Natural Science Foundation of China(grant no.21722308 and 21802146)by Beijing Natural Science Foundation(2192064)+1 种基金by the National Project Development of Advanced Scientific Instruments Based on Deep Ultraviolet Laser Source(no.Y31M0112C1)by Key Research Program of Frontier Sciences(CAS,Grant QYZDBSSW-SLH024).
文摘The identification of highly abundant,“magic”spe-cies in the mass spectra of clusters have proven to be valuable in nanoscience,leading to the discovery of new stable species such as fullerenes and the elec-tronic shell structures of metallic clusters.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 50271026).
文摘A molecular dynamics simulation study has been performed for a large sys- tem consisting of 100000 liquid metal Al atoms to investigate the formation and magic number characteristics of the cluster configurations formed during the rapid solidification processes. The cluster-type index method (CTIM) has been adopted to describe various types of cluster configurations. The results indicate that the icosahedral clusters (12 0 12 0) and their combinations play the most important role in the microstructure transitions during solidification processes; for the cluster configurations of different levels formed by various combinations with differing numbers of basic clusters, their size distributions possess ob- vious magic number sequence which is in turn as 13(13), 19(21), 26-28(27), 32-33(32), 39-40, 43-44, 48…, (those in bracket are the corresponding value in liquid state); the magic numbers correspond to the peak value positions of the cluster numbers for corre- sponding level formed with various combinations by 1, 2, 3, 4, 5, 6, 7, …basic clusters, respectively. This magic number sequence is in good agreement with the experimental results obtained by Harris et al. At the same time, this simulation study also gives a scien- tific and reasonable explanation to these experimental results.
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.
文摘对于图G(V,E),若存在正整数k(1≤k≤|G|+|E|)和映射f:V(G)∪Ε(G)→{1,2,…,k},使得对任意两点u,v∈V(G),有S(u)=S(v),其中S(u)=f(u)+∑_(uw∈E(G))f(uw),则称f为G的点魔幻全染色,且称χVMTC(G)=max{k|k-VMTC of G}为点魔幻全色数.在已有的点魔幻标号和点可区别染色研究基础之上,结合实际问题提出了点魔幻全染色(VMTC),设计了一种新型的点魔幻全染色算法,该算法使用迭代寻优的方式对随机图进行了研究,通过实验结果分析,总结得到了若干定理并给出证明.
文摘The production mechanism of Cu/Cl binary clusters were investigated by laser vaporization of CuCl, CuCl2, CuCl2·2H2O by time-of-flight mass spectrometry. We found that lager cluster size can be detected by using CuCl2·2H2O solid pellets than CuCl2 and CuCl. Only Cu+(CuCl)n, (CuCl)n, n <8 were observed when 532 um laser vaporized the CuCl. We also found almost the same cluster using CuCl2 and CuCl2·2H2O in the same mass range, deficit Cu clusters were dominated for clusters with more than five Cu atoms when using CuCl2, CuCl2·2H2O compounds. The relation of relative intensity In2:/In-1In+1 vs. different size of clusters were almost the same using different compounds above. (CuCl)3+.(CuCl)+6 ions in (CuCl)+n series, and Cu6Cl+5 in Cu(CuCl)+n series have special stability. The magic number observed above are different from those of alkali halide (MX) clusters, hexagonal structures were proposed for the above magic number clusters.
