636 research outputs found
Completely packed O(n) loop models and their relation with exactly solved coloring models.
Theoretical Physic
Nucleon-nucleon momentum correlation function for light nuclei
Nucleon-nucleon momentum correlation function have been presented for nuclear
reactions with neutron-rich or proton-rich projectiles using a nuclear
transport theory, namely Isospin-Dependent Quantum Molecular Dynamics model.
The relationship between the binding energy of projectiles and the strength of
proton-neutron correlation function at small relative momentum has been
explored, while proton-proton correlation function shows its sensitivity to the
proton density distribution. Those results show that nucleon-nucleon
correlation function is useful to reflect some features of the neutron- or
proton-halo nuclei and therefore provide a potential tool for the studies of
radioactive beam physics.Comment: Talk given at the 18th International IUPAP Conference on Few-Body
Problems in Physics (FB18), Santos, Brasil, August 21-26, 2006. To appear in
Nucl. Phys.
First Report of Alternaria Black Spot Disease Caused by Alternaria alternata on the Invasive Weed Solanum rostratum in Xinjiang, China
Solanum rostratum is a noxious weed, native to Mexico and the USA, which has invaded Liaoning, Jilin, Hebei, Inner
Mongolia, Shanxi, Xinjiang and Beijing, China (Eminniya et al., 2013). In August 2015, foliar symptoms of yellowish to black
spots were observed on plants of S. rostratum nearby an agricultural plantation in Changji, Xinjiang. The following year, about
17% of the 206 plants surveyed on about 0.2 ha of deserted farmland were infected from July-September (at 19-35°C under
29-97% RH)
Neutron/proton ratio of nucleon emissions as a probe of neutron skin
The dependence between neutron-to-proton yield ratio () and neutron
skin thickness () in neutron-rich projectile induced reactions is
investigated within the framework of the Isospin-Dependent Quantum Molecular
Dynamics (IQMD) model. The density distribution of the Droplet model is
embedded in the initialization of the neutron and proton densities in the
present IQMD model. By adjusting the diffuseness parameter of neutron density
in the Droplet model for the projectile, the relationship between the neutron
skin thickness and the corresponding in the collisions is obtained.
The results show strong linear correlation between and
for neutron-rich Ca and Ni isotopes. It is suggested that may be used
as an experimental observable to extract for neutron-rich nuclei,
which is very significant to the study of the nuclear structure of exotic
nuclei and the equation of state (EOS) of asymmetric nuclear matter.Comment: 7 pages, 5 figures; accepted by Phys. Lett.
Scaling of anisotropy flows in intermediate energy heavy ion collisions
Anisotropic flows (, and ) of light nuclear clusters are
studied by a nucleonic transport model in intermediate energy heavy ion
collisions. The number-of-nucleon scalings of the directed flow () and
elliptic flow () are demonstrated for light nuclear clusters. Moreover,
the ratios of of nuclear clusters show a constant value of 1/2
regardless of the transverse momentum. The above phenomena can be understood by
the coalescence mechanism in nucleonic level and are worthy to be explored in
experiments.Comment: Invited talk at "IX International Conference on Nucleus-Nucleus
Collisions", Rio de Janeiro, Aug 28- Sept 1, 2006; to appear on the
proceeding issue in Nuclear Physics
The accelerated scaling attractor solution of the interacting agegraphic dark energy in Brans-Dicke theory
We investigate the interacting agegraphic dark energy in Brans-Dicke theory
and introduce a new series general forms of dark sector coupling. As examples,
we select three cases involving a linear interaction form (Model I) and two
nonlinear interaction form (Model II and Model III). Our conclusions show that
the accelerated scaling attractor solutions do exist in these models. We also
find that these interacting agegraphic dark energy modes are consistent with
the observational data. The difference in these models is that nonlinear
interaction forms give more approached evolution to the standard CDM
model than the linear one. Our work implies that the nonlinear interaction
forms should be payed more attention.Comment: 9 pages, 10 figures, accepted in Eur. Phys. J.
Vanishing Effective Mass of the Neutrinoless Double Beta Decay?
We stress that massive neutrinos may be Majorana particles even if the
effective mass of the neutrinoless double beta decay m_ee vanishes. We show
that current neutrino oscillation data do allow m_ee = 0 to hold, if the
Majorana CP-violating phases lie in two specific regions. Strong constraints on
three neutrino masses can then be obtained. We find that the neutrino mass
spectrum performs a normal hierarchy: m_1 < m_2 < m_3. A possible texture of
the neutrino mass matrix is also illustrated under the m_ee = 0 condition.Comment: RevTex 9 pages (2 PS figures included). More discussions and
references added. Results partly changed. To appear in Phys. Rev.
The Vacuum System of HIRFL
AbstractThe vacuum system of Heavy Ion Research Facility in Lanzhou (HIRFL) is a large and complex system. HIRFL consists of two ECR ion sources, a sector focus cyclotron (SFC), a separate sector cyclotron (SSC) and a multi-purpose cooling storage ring system which has a main ring (CSRm) and an experiment ring (CSRe). Several beam lines connect these accelerators together and transfer various heavy ion beams to more than 10 experiment terminals. According to the requirements of the ion acceleration and ion lifetime, the working pressure in each accelerator is different. SFC is nearly 50 years old. After upgrade, the working pressure in SFC is improved from 10-6mbar to 10-8mbar. The pressure in SSC which was built in the 1980s reaches the same level. The cooling storage ring system with a length of 500m came into operation in 2007. The average pressures in CSRm and CSRe are 5×10-12mbar and 8×10-12mbar respectively. Different designs were adopt for vacuum system of a dozen beam lines to meet specific requirement of each experiment terminal. Along with the extensive development of the heavy ion researches and applications, new accelerators of HIRFL are under construction. The vacuum system of the new machines will be designed and constructed followed the overall schedule
Scaling of Anisotropic Flow and Momentum-Space Densities for Light Particles in Intermediate Energy Heavy Ion Collisions
Anisotropic flows ( and ) of light nuclear clusters are studied by
Isospin-Dependent Quantum Molecular Dynamics model for the system of Kr
+ Sn at intermediate energy and large impact parameters.
Number-of-nucleon scaling of the elliptic flow () are demonstrated for the
light fragments up to = 4, and the ratio of shows a constant
value of 1/2. In addition, the momentum-space densities of different clusters
are also surveyed as functions of transverse momentum, in-plane transverse
momentum and azimuth angle relative to the reaction plane. The results can be
essentially described by momentum-space power law. All the above phenomena
indicate that there exists a number-of-nucleon scaling for both anisotropic
flow and momentum-space densities for light clusters, which can be understood
by the coalescence mechanism in nucleonic degree of freedom for the cluster
formation.Comment: 8 pages, 3 figures; to be published in Physics Letters
Dynamics of Tachyon and Phantom Field beyond the Inverse Square Potentials
We investigate the cosmological evolution of the tachyon and phantom-tachyon
scalar field by considering the potential parameter () as a function of another potential parameter
(), which correspondingly extends the
analysis of the evolution of our universe from two-dimensional autonomous
dynamical system to the three-dimension. It allows us to investigate the more
general situation where the potential is not restricted to inverse square
potential and .One result is that, apart from the inverse square potential,
there are a large number of potentials which can give the scaling and dominant
solution when the function equals for one or some
values of as well as the parameter satisfies
condition Eq.(18) or Eq.(19). We also find that for a class of different
potentials the dynamics evolution of the universe are actually the same and
therefore undistinguishable.Comment: 8 pages, no figure, accepted by The European Physical Journal
C(2010), online first,
http://www.springerlink.com/content/323417h708gun5g8/?p=dd373adf23b84743b523a3fa249d51c7&pi=
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