693 research outputs found
3D DEM Simulation of Crushable Granular Soils under Plane Strain Compression Condition
AbstractParticle crushing plays an important role on the mechanical behavior of crushable granular soils. In this paper, the macro- and micro-mechanical behaviors of dense granular soils composed of crushable agglomerates in plane strain compression test are investigated using the Discrete Element Method (DEM). A detailed study on the effects of particle crushing on the soil behavior is facilitated by a comparison between the simulation results of crushable and uncrushable specimens. The DEM results show a strong dependency of particle crushing on the confining stress level. It is found that under low confining stresses, particle crushing is insignificant and does not affect the shear band formation, which is the primary failure mode in an uncrushable specimen. However, under high confining stresses, significant particle crushing occurs and leads to considerable volumetric compression and reduction of the peak shear stress ratio. More importantly, particle crushing interferes with the formation of shear band and results in massive contractive zones in the specimen, which essentially controls the shear strength behavior
3D DEM Simulation of Crushable Granular Soils under Plane Strain Compression Condition
AbstractParticle crushing plays an important role on the mechanical behavior of crushable granular soils. In this paper, the macro- and micro-mechanical behaviors of dense granular soils composed of crushable agglomerates in plane strain compression test are investigated using the Discrete Element Method (DEM). A detailed study on the effects of particle crushing on the soil behavior is facilitated by a comparison between the simulation results of crushable and uncrushable specimens. The DEM results show a strong dependency of particle crushing on the confining stress level. It is found that under low confining stresses, particle crushing is insignificant and does not affect the shear band formation, which is the primary failure mode in an uncrushable specimen. However, under high confining stresses, significant particle crushing occurs and leads to considerable volumetric compression and reduction of the peak shear stress ratio. More importantly, particle crushing interferes with the formation of shear band and results in massive contractive zones in the specimen, which essentially controls the shear strength behavior
Quantum algebra in the mixed light pseudoscalar meson states
In this paper, we investigate the entanglement degrees of pseudoscalar meson
states via quantum algebra Y(su(3)). By making use of transition effect of
generators J of Y(su(3)), we construct various transition operators in terms of
J of Y(su(3)), and act them on eta-pion-eta mixing meson state. The
entanglement degrees of both the initial state and final state are calculated
with the help of entropy theory. The diagrams of entanglement degrees are
presented. Our result shows that a state with desired entanglement degree can
be achieved by acting proper chosen transition operator on an initial state.
This sheds new light on the connect among quantum information, particle physics
and Yangian algebra.Comment: 9 pages, 3 figure
Confront Holographic QCD with Regge Trajectories of vectors and axial-vectors
We derive the general 5-dimension metric structure of the system in
type II superstring theory, and demonstrate the physical meaning of the
parameters characterizing the 5-dimension metric structure of the
\textit{holographic} QCD model by relating them to the parameters describing
Regge trajectories. By matching the spectra of vector mesons with
deformed soft-wall model, we find that the spectra of vector mesons
can be described very well in the soft-wall model, i.e,
soft-wall model. We then investigate how well the soft-wall
model can describe the Regge trajectory of axial-vector mesons . We find
that the constant component of the 5-dimension mass square of axial-vector
mesons plays an efficient role to realize the chiral symmetry breaking in the
vacuum, and a small negative correction in the 5-dimension mass square is
helpful to realize the chiral symmetry restoration in high excitation states.Comment: 9 pages, 3 figure and 3 tables, one section adde
Measurements of the observed cross sections for exclusive light hadrons containing at , 3.650 and 3.6648 GeV
By analyzing the data sets of 17.3, 6.5 and 1.0 pb taken,
respectively, at , 3.650 and 3.6648 GeV with the BES-II
detector at the BEPC collider, we measure the observed cross sections for
, , ,
and at the three energy
points. Based on these cross sections we set the upper limits on the observed
cross sections and the branching fractions for decay into these
final states at 90% C.L..Comment: 7 pages, 2 figure
Partial wave analysis of J/\psi \to \gamma \phi \phi
Using events collected in the BESII detector, the
radiative decay is
studied. The invariant mass distribution exhibits a near-threshold
enhancement that peaks around 2.24 GeV/.
A partial wave analysis shows that the structure is dominated by a
state () with a mass of
GeV/ and a width of GeV/. The
product branching fraction is: .Comment: 11 pages, 4 figures. corrected proof for journa
Direct Measurements of Absolute Branching Fractions for D0 and D+ Inclusive Semimuonic Decays
By analyzing about 33 data sample collected at and around 3.773
GeV with the BES-II detector at the BEPC collider, we directly measure the
branching fractions for the neutral and charged inclusive semimuonic decays
to be and , and determine the ratio of the two branching
fractions to be
Symmetry and topology in antiferromagnetic spintronics
Antiferromagnetic spintronics focuses on investigating and using
antiferromagnets as active elements in spintronics structures. Last decade
advances in relativistic spintronics led to the discovery of the staggered,
current-induced field in antiferromagnets. The corresponding N\'{e}el
spin-orbit torque allowed for efficient electrical switching of
antiferromagnetic moments and, in combination with electrical readout, for the
demonstration of experimental antiferromagnetic memory devices. In parallel,
the anomalous Hall effect was predicted and subsequently observed in
antiferromagnets. A new field of spintronics based on antiferromagnets has
emerged. We will focus here on the introduction into the most significant
discoveries which shaped the field together with a more recent spin-off
focusing on combining antiferromagnetic spintronics with topological effects,
such as antiferromagnetic topological semimetals and insulators, and the
interplay of antiferromagnetism, topology, and superconductivity in
heterostructures.Comment: Book chapte
The energy spectrum of all-particle cosmic rays around the knee region observed with the Tibet-III air-shower array
We have already reported the first result on the all-particle spectrum around
the knee region based on data from 2000 November to 2001 October observed by
the Tibet-III air-shower array. In this paper, we present an updated result
using data set collected in the period from 2000 November through 2004 October
in a wide range over 3 decades between eV and eV, in which
the position of the knee is clearly seen at around 4 PeV. The spectral index is
-2.68 0.02(stat.) below 1PeV, while it is -3.12 0.01(stat.) above 4
PeV in the case of QGSJET+HD model, and various systematic errors are under
study now.Comment: 12 pages, 7 figures, accepted by Advances in space researc
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