HAMILTONIAN DECOMPOSITION OF COMPLETE BIPARTITE γ-HYPERGRAPHS

1. IntroductionHypergraphs are most general structure in discrete mathematics. Computer scientistsintroduced the concept of acyclic hypergraphs and proved that acyc1ic hypergraphs are veryuseful in database theory['--']. In [l], a new system of axioms fOr paths, connectivity andcycles of hypergraphs was introduced. In this paper, we wiIl introduce the concepts ofbipartite hypergraphs and Hamiltonian paths and cycles of a hypergraph.Let V be a finite set. n = (V e) is called a hypergraph on …     

Breit势的正规化与ηc-J/ψ的劈裂

研究自旋和轨道量子数不同的介子之间的质量劈裂对检验夸克势模型非常重要。 在以往的夸克势模型计算中,η_c-J/ψ的质量劈裂都很难达到实验的值。 用正规化形状因子μ2/(q2+μ2)， 在对完整的动量空间中的Breit夸克势实施一次正规化下研究了η_c-J/ψ和新介子ηb与Υ(1s)之间的质量劈裂。 结果表明， 正规化形状因子中的屏蔽质量μ应与介子折合质量有关， 当将其展开为介子折合质量的三阶多项式时， 上述介子质量劈裂可以精确重现实验的结果。另外， 由于完整的Breit势包含有自旋-轨道耦合相互作用的项，因而还可以研究χc0,χc1和χc2之间的质量劈裂。 The study of the splittings between the masses of mesons with different spin and orbit quantum numbers is important for checking the quark potential model. In the previous calculations with quark potential models, the splitting between ηc and J/ψ is however too small to the experimental result. In this paper the mass splitting of ηc J/ψ and the splitting between the new meson ηb and Υ(1s) are investigated with the complete Breit quark potential regularized by applying the form factor μ2/(q2+μ2) one time in momentum space. In addition, because the complete Breit potential includes the spin orbit interaction, it can be used to investigate the splittings among χc0, χc1 and χc2. The investigated results indicate that the screen mass μ in the form factor of regularization is related to the reduced mass of meson. The splittings of η_c-J/ψ, ηb Υ, and χc0 χc1 χc2 can reproduce the experimental results with high accuracy when the screen mass is expanded to the third order polynomial of meson reduced mass.     

利用imaging方法提取高能重离子碰撞中Core-Halo模型发射源的信息

根据对高斯源的检验, 引入两个π介子相对距离的均方根半径R_rmst来表示高能重离子碰撞中π介子发射源的空间尺寸。 利用imaging计算方法可以不依赖于源模型计算出相对距离的均方根半径。 对Core-Halo模型进行计算并与高斯拟合结果比较, 结果显示, 由于长寿命共振态衰变产生的π介子的贡献, 半径R_rmst显示出较大的π介子发射空间。 另外,对于π介子为混沌发射的情况, 通过imaging方法计算得到的π介子发射源的混沌性参量明显大于高斯拟合所得到的结果。     

单圈图生成的凯莱图UG_n在PMC模型和MM~*模型下的1好邻诊断度

多处理系统的诊断度是一个重要的研究课题.一种新的系统故障诊断方法称为g好邻诊断度,它是限制每个无故障点至少包含g个无故障的邻点.单圈图生成的凯莱图UG_n作为一种极好的互联网络拓扑结构有许多好的性质.现证明了当n≥4时,单圈图生成的凯莱图UG_n在PMC模型下的1好邻诊断度是2n-1;当n≥5时,UG_n在MM~*模型下的1好邻诊断度是2n-1.     

无圈超图规模的进一步研究

本文在王建方给出的严格(d)-连通κ-匀齐无圈超图的规模的基础上,进一步研究n阶(d)-连通κ-匀齐无圈超图的规模和非严格(d)-连通κ-匀齐无圈超图的规模,并分别得到它们规模的上下界.     

Two-pion interferometry in heavy ion collisions at HIRFL-CSR energy

We examine the two-pion Hanbury-Brown-Twiss (HBT) interferometry for the particle-emitting source produced in heavy ion collisions at HIRFL-CSR energy. The source evolution is described by relativistic hydrodynamics with three kinds of equations of state for chemical equilibrium (CE), chemical freeze-out (CFO), and partial chemical equilibrium (PCE) models, respectively. We investigate the effects of particle decay, multiple scattering, and source collective expansion on the two-pion interferometry results. We find that the HBT radii of the evolution source for the CFO and PCE models are smaller than that for the CE model. The HBT lifetime for the CFO model is smaller than those for the PCE and CE models. The particle decay increases the HBT radius and lifetime while the source     

关于DNA图及其标号图的进一步研究

2007年,Wang等得到了关于不包含环的DNA标号图的一个结果,在此基础上我们推广到一般有向图上,即任何无孤立点的有向图在友关系下恰有—个等价类的充要条件,并得出几个相应的改进结果.本文还给出了一个定理的反例,进而得到定理的修正和完善.由此容易推出Wang等的一个定理的必要条件也是充分的.     

Two-pion interferometry in heavy ion collisions at HIRFL-CSR energy

We examine the two-pion Hanbury-Brown-Twiss (HBT) interferometry for the particle-emitting source produced in heavy ion collisions at HIRFL-CSR energy. The source evolution is described by relativistic hydrodynamics with three kinds of equations of state for chemical equilibrium (CE), chemical freeze-out (CFO),and partial chemical equilibrium (PCE) models, respectively. We investigate the effects of particle decay,multiple scattering, and source collective expansion on the two-pion interferometry results. We find that the HBT radii of the evolution source for the CFO and PCE models are smaller than that for the CE model.The HBT lifetime for the CFO model is smaller than those for the PCE and CE models. The particle decay increases the HBT radius and lifetime while the source expansion decreases the HBT radius. The multiple scattering effect on the HBT results can be neglected based on our model calculations.     

颗粒相干发射源的2π和3π玻色-爱因斯坦关联

在假设由同一颗粒发射的π介子为相干发射的条件下, 给出了颗粒发射源模型的2π及3π关联函数, 发射源的混沌性随颗粒数目的增加而增大. 此外, 对颗粒相干发射源及部分相干高斯源的归一化纯3π关联进行比较, 发现当2π关联的混沌性参量小于0.8时, 两种发射源的归一化纯3π关联值在小Q₃区域有明显差别.