Two kinds of glassy sulfurs are synthesized by thrapid compression method from liquid sulfur at temperatures below and above the X-transition point. The glassy sulfur has different colors and transparencies, depending...Two kinds of glassy sulfurs are synthesized by thrapid compression method from liquid sulfur at temperatures below and above the X-transition point. The glassy sulfur has different colors and transparencies, depending on temperature, which may inherit some structural information from the transition. Raman spectrum studies of these samples show that a large fraction of polymeric chains exist in the glassy sulfur, even in the one solidified from T 〈 Tλ. We find that a higher compression rate instead of a higher temperature of the parent liquid captures more polymeric chains. Pressure-induced glassy sulfur presents high thermal stability compared with temperature quenched glassy sulfur and could transform into liquid sulfur directly without crystallization through an abnormal exothermic melting course. High energy x-ray diffraction is utilized to study the local order of the pressure-induced glassy sulfur.展开更多
Key nuclear inputs for the astrophysical r-process simulations are the weak interaction rates.Consequently,the accuracy of these inputs directly affects the reliability of nucleosynthesis modeling.The majority of the ...Key nuclear inputs for the astrophysical r-process simulations are the weak interaction rates.Consequently,the accuracy of these inputs directly affects the reliability of nucleosynthesis modeling.The majority of the stellar rates,used in simulation studies are calculated by invoking the Brink-Axel(BA)hypothesis.The BA hypothesis assumes that the strength functions of all parent excited states are the same as for the ground state,only shifted in energies.However,the BA hypothesis has to be tested against microscopically calculated state-by-state rates.In this project,we study the impact of the BA hypothesis on calculated stellarβ^(-)-decay and electron capture rates.Our investigation include both unique first forbidden(U1F)and allowed transitions for 106 neutron-rich trans-iron nuclei([27,77]≤[Z,A]≤[82,208]).The calculations were performed using the deformed proton-neutron quasiparticle random-phase approximation(pn-QRPA)model with a simple plus quadrupole separable and schematic interaction.Waiting-point and several key r-process nuclei lie within the considered mass region of the nuclear chart.We computed electron capture andβ^(-)-decay rates using two different prescriptions for strength functions.One was based on invoking the BA hypothesis and the other was the state-by-state calculation of strength functions,under stellar density and temperature conditions([10,1]≤[ρYe(g/cm^(3)),T(GK)]≤[10^(11),30]).Our results show that the BA hypothesis invoked U1Fβ^(-)rates are overestimated by 4–5 orders of magnitude as compared to microscopic rates.For capture rates,more than two orders of magnitude differences were noted when applying the BA hypothesis.It was concluded that the BA hypothesis is not a reliable approximation,especially forβ^(-)-decay forbidden transitions.展开更多
Let <img alt="" src="Edit_6a94976d-35be-4dd4-b74f-d0bf6f497453.png" />be a non-autonomous discrete system and <img alt="" src="Edit_3516e048-3d23-4ae8-81ac-e7e732efbc89...Let <img alt="" src="Edit_6a94976d-35be-4dd4-b74f-d0bf6f497453.png" />be a non-autonomous discrete system and <img alt="" src="Edit_3516e048-3d23-4ae8-81ac-e7e732efbc89.png" /> be a set-valued discrete system induced by it. Where, <img alt="" src="Edit_f67612c1-bbf4-4c21-8b37-7d156ca9502d.png" />is the space formed by all non-empty compact subsets of <em>X</em> endowed with the Hausdorff metric <em>H</em>, <img alt="" src="Edit_cca16788-f64a-47c4-9645-e9c8cf9080fd.png" />is a set-valued mapping sequence induced by <img alt="" src="Edit_5a6d2e7f-3245-4dbd-98ec-dc977e23f3d8.png" />. It is proved that <img alt="" src="Edit_a25ef428-a2ff-46d5-9109-dcc67b57fbec.png" /> is <img alt="" src="Edit_ee8759ba-215c-4088-8590-db9f57eb4a7c.png" />-chaos, then <img alt="" src="Edit_f54b347a-033e-43e2-a3a1-d2fe5ac1f39d.png" />is <img alt="" src="Edit_72a57e59-dc43-4071-b0fe-432e379ddcc9.png" />-chaos. Where <img alt="" src="Edit_97813401-14af-4776-99fe-1e6cd08c3df1.png" />-chaos is denoted to <img alt="" src="Edit_9e2d88b4-7ece-430e-8978-800ff3280799.png" />-sensitive, <img alt="" src="Edit_440b79c1-f679-4571-b14d-6f804f402d75.png" />-sensitive, <img alt="" src="Edit_839b7b55-9961-4d80-b5cb-e7219a0ae871.png" />-transitive, <img alt="" src="Edit_feb0a032-255b-4cbd-b489-6a937c5a287a.png" />-accessible, <img alt="" src="Edit_3ba59c02-6df0-4ae1-8ac0-5c1b620e4a88.png" />-weakly mixing, <img alt="" src="Edit_7362ed03-8686-4cf7-94df-f0933b7abbff.png" />-<em>m</em>-sensitive, infinitely sensitive, or syndetically transitive.展开更多
Let X be a finite simple undirected graph and G an automorphism group of X. If G is transitive on s-arcs but not on (s + 1)-arcs then X is called (G, s)-transitive. Let X be a connected (G, s)-transitive graph ...Let X be a finite simple undirected graph and G an automorphism group of X. If G is transitive on s-arcs but not on (s + 1)-arcs then X is called (G, s)-transitive. Let X be a connected (G, s)-transitive graph of a prime valency p, and Gv the vertex stabilizer of a vertex v E V(X) in G. For the case p = 3, the exact structure of Gv has been determined by Djokovid and Miller in [Regular groups of automorphisms of cubic graphs, J. Combin. Theory (Ser. B) 29 (1980) 195-230]. For the case p = 5, all the possibilities of Gv have been given by Guo and Feng in [A note on pentavalent s-transitive graphs, Discrete Math. 312 (2012) 2214-2216]. In this paper, we deal with the case p = 7 and determine the exact structure of the vertex stabilizer Gv.展开更多
In this paper we have completely determined:(1)all almost simple groups which act 2-transitively on one of their sets of Sylow p-subgroups.(2)all non-abelian simple groups T whose automorphism group acts 2-transitivel...In this paper we have completely determined:(1)all almost simple groups which act 2-transitively on one of their sets of Sylow p-subgroups.(2)all non-abelian simple groups T whose automorphism group acts 2-transitively on one of the sets of Sylow p-subgroups of T.(3)all finite groups which are 2-transitive on all their sets of Sylow subgroups.展开更多
The high spin states of the neutron-rich odd-odd 106Tc nucleus have been reinvestigated by observing prompt γ-rays from the spontaneous fission of 252Cf. A previously known collective band is confirmed and expanded, ...The high spin states of the neutron-rich odd-odd 106Tc nucleus have been reinvestigated by observing prompt γ-rays from the spontaneous fission of 252Cf. A previously known collective band is confirmed and expanded, and a new collective band is newly identified. Several levels in previous report in 106Tc are reexamined and they belong to the members of a band in 107Tc. The total Routhian surface (TRS) calculations show that the 106Tc has triaxial shape. The spins and parities as well as the configurations for these bands have been tentatively assigned according to the analysis of the angular momentum alignments.展开更多
Levels in the neutron-rich 109Ru have been studied by observing the prompt γ-rays following the spontaneous fission fragments of 252Cf. The ground state band and the negative parity bands have been confirmed and exte...Levels in the neutron-rich 109Ru have been studied by observing the prompt γ-rays following the spontaneous fission fragments of 252Cf. The ground state band and the negative parity bands have been confirmed and extended. A positive parity band with the band head level at 332.5 keV is newly identified and suggested as a single-neutron excitation band built on the 7/2+[404] Nilsson orbital. Some structural characteristics of these bands are discussed.展开更多
In this paper, we discuss the G-decomposition of λKv into 6-circuits with two chords. We construct some holey G-designs using sharply 2-transitive group, and present the recursive structure by PBD. We also give a uni...In this paper, we discuss the G-decomposition of λKv into 6-circuits with two chords. We construct some holey G-designs using sharply 2-transitive group, and present the recursive structure by PBD. We also give a unified method to construct G-designs when the index equals the edge number of the discussed graph. Finally, the existence of G-GDλ(v) is given.展开更多
基金supported by the Joint Funds of the National Natural Science Foundation of China(Grant No.U1530402)the National Natural Science Foundation of China(Grant No.11004163)+2 种基金the Fundamental Research Funds for the Central Universities,China(Grant No.2682014ZT31)the Department of Energy National Nuclear Security Administration(Grant No.DE-NA0001974)the Department of Energy Basic Energy Sciences(Grant Nos.DE-FG02-99ER45775and DE-AC02-06CH11357)
文摘Two kinds of glassy sulfurs are synthesized by thrapid compression method from liquid sulfur at temperatures below and above the X-transition point. The glassy sulfur has different colors and transparencies, depending on temperature, which may inherit some structural information from the transition. Raman spectrum studies of these samples show that a large fraction of polymeric chains exist in the glassy sulfur, even in the one solidified from T 〈 Tλ. We find that a higher compression rate instead of a higher temperature of the parent liquid captures more polymeric chains. Pressure-induced glassy sulfur presents high thermal stability compared with temperature quenched glassy sulfur and could transform into liquid sulfur directly without crystallization through an abnormal exothermic melting course. High energy x-ray diffraction is utilized to study the local order of the pressure-induced glassy sulfur.
基金supported by the Higher Education Commission Pakistan through Project (0-15394/NRPU/R&D/HEC/2021)。
文摘Key nuclear inputs for the astrophysical r-process simulations are the weak interaction rates.Consequently,the accuracy of these inputs directly affects the reliability of nucleosynthesis modeling.The majority of the stellar rates,used in simulation studies are calculated by invoking the Brink-Axel(BA)hypothesis.The BA hypothesis assumes that the strength functions of all parent excited states are the same as for the ground state,only shifted in energies.However,the BA hypothesis has to be tested against microscopically calculated state-by-state rates.In this project,we study the impact of the BA hypothesis on calculated stellarβ^(-)-decay and electron capture rates.Our investigation include both unique first forbidden(U1F)and allowed transitions for 106 neutron-rich trans-iron nuclei([27,77]≤[Z,A]≤[82,208]).The calculations were performed using the deformed proton-neutron quasiparticle random-phase approximation(pn-QRPA)model with a simple plus quadrupole separable and schematic interaction.Waiting-point and several key r-process nuclei lie within the considered mass region of the nuclear chart.We computed electron capture andβ^(-)-decay rates using two different prescriptions for strength functions.One was based on invoking the BA hypothesis and the other was the state-by-state calculation of strength functions,under stellar density and temperature conditions([10,1]≤[ρYe(g/cm^(3)),T(GK)]≤[10^(11),30]).Our results show that the BA hypothesis invoked U1Fβ^(-)rates are overestimated by 4–5 orders of magnitude as compared to microscopic rates.For capture rates,more than two orders of magnitude differences were noted when applying the BA hypothesis.It was concluded that the BA hypothesis is not a reliable approximation,especially forβ^(-)-decay forbidden transitions.
文摘Let <img alt="" src="Edit_6a94976d-35be-4dd4-b74f-d0bf6f497453.png" />be a non-autonomous discrete system and <img alt="" src="Edit_3516e048-3d23-4ae8-81ac-e7e732efbc89.png" /> be a set-valued discrete system induced by it. Where, <img alt="" src="Edit_f67612c1-bbf4-4c21-8b37-7d156ca9502d.png" />is the space formed by all non-empty compact subsets of <em>X</em> endowed with the Hausdorff metric <em>H</em>, <img alt="" src="Edit_cca16788-f64a-47c4-9645-e9c8cf9080fd.png" />is a set-valued mapping sequence induced by <img alt="" src="Edit_5a6d2e7f-3245-4dbd-98ec-dc977e23f3d8.png" />. It is proved that <img alt="" src="Edit_a25ef428-a2ff-46d5-9109-dcc67b57fbec.png" /> is <img alt="" src="Edit_ee8759ba-215c-4088-8590-db9f57eb4a7c.png" />-chaos, then <img alt="" src="Edit_f54b347a-033e-43e2-a3a1-d2fe5ac1f39d.png" />is <img alt="" src="Edit_72a57e59-dc43-4071-b0fe-432e379ddcc9.png" />-chaos. Where <img alt="" src="Edit_97813401-14af-4776-99fe-1e6cd08c3df1.png" />-chaos is denoted to <img alt="" src="Edit_9e2d88b4-7ece-430e-8978-800ff3280799.png" />-sensitive, <img alt="" src="Edit_440b79c1-f679-4571-b14d-6f804f402d75.png" />-sensitive, <img alt="" src="Edit_839b7b55-9961-4d80-b5cb-e7219a0ae871.png" />-transitive, <img alt="" src="Edit_feb0a032-255b-4cbd-b489-6a937c5a287a.png" />-accessible, <img alt="" src="Edit_3ba59c02-6df0-4ae1-8ac0-5c1b620e4a88.png" />-weakly mixing, <img alt="" src="Edit_7362ed03-8686-4cf7-94df-f0933b7abbff.png" />-<em>m</em>-sensitive, infinitely sensitive, or syndetically transitive.
基金This work was supported by the National Natural Science Foundation of China (11301154, 11271012, 11301159, 11101035, 11326056), the Key Project of Education Department of Henan Province Scientific and Technological Research (13A110249) and the Scientific Re- search Foundation for Doctoral Scholars of HAUST (09001707).
文摘Let X be a finite simple undirected graph and G an automorphism group of X. If G is transitive on s-arcs but not on (s + 1)-arcs then X is called (G, s)-transitive. Let X be a connected (G, s)-transitive graph of a prime valency p, and Gv the vertex stabilizer of a vertex v E V(X) in G. For the case p = 3, the exact structure of Gv has been determined by Djokovid and Miller in [Regular groups of automorphisms of cubic graphs, J. Combin. Theory (Ser. B) 29 (1980) 195-230]. For the case p = 5, all the possibilities of Gv have been given by Guo and Feng in [A note on pentavalent s-transitive graphs, Discrete Math. 312 (2012) 2214-2216]. In this paper, we deal with the case p = 7 and determine the exact structure of the vertex stabilizer Gv.
基金The first author acknowledges the support of OPR Scholarship of Australia The second author is supported by the National Natural Science Foundation of China.Thanks are also due to the Department of Mathematics,the University of Western Australia,where he
文摘In this paper we have completely determined:(1)all almost simple groups which act 2-transitively on one of their sets of Sylow p-subgroups.(2)all non-abelian simple groups T whose automorphism group acts 2-transitively on one of the sets of Sylow p-subgroups of T.(3)all finite groups which are 2-transitive on all their sets of Sylow subgroups.
基金Supported by National Natural Science Foundation of China (10575057, 10775078)Major State Basic Research Development Program (2007CB815005)+1 种基金Special Program of Higher Education Science Foundation (20070003149)U. S. Department of Energy (DE-FG05-88ER40407, DE-AC03-76SF00098)
文摘The high spin states of the neutron-rich odd-odd 106Tc nucleus have been reinvestigated by observing prompt γ-rays from the spontaneous fission of 252Cf. A previously known collective band is confirmed and expanded, and a new collective band is newly identified. Several levels in previous report in 106Tc are reexamined and they belong to the members of a band in 107Tc. The total Routhian surface (TRS) calculations show that the 106Tc has triaxial shape. The spins and parities as well as the configurations for these bands have been tentatively assigned according to the analysis of the angular momentum alignments.
基金Supported by National Natural Science Foundation of China (10575057, 10775078)Major State Basic Research Development Program (2007CB815005)+1 种基金Doctoral Program Foundation of Institutions of Higher Education of China (20070003149)U. S. Department of Energy (DE-FG05-88ER40407, DE-AC03-76SF00098)
文摘Levels in the neutron-rich 109Ru have been studied by observing the prompt γ-rays following the spontaneous fission fragments of 252Cf. The ground state band and the negative parity bands have been confirmed and extended. A positive parity band with the band head level at 332.5 keV is newly identified and suggested as a single-neutron excitation band built on the 7/2+[404] Nilsson orbital. Some structural characteristics of these bands are discussed.
基金Foundation item: the National Natural Science Foundation of China (No. 10671055) the Natural Science Foundation of Hebei Province (No. A2007000230) the Foundation of Hebei Normal University (No. L2007B22).
文摘In this paper, we discuss the G-decomposition of λKv into 6-circuits with two chords. We construct some holey G-designs using sharply 2-transitive group, and present the recursive structure by PBD. We also give a unified method to construct G-designs when the index equals the edge number of the discussed graph. Finally, the existence of G-GDλ(v) is given.