29,752 research outputs found
The Relativistic Rotation
The classical rotation is not self-consistent in the framework of the special
theory of relativity. the Relativistic rotation is obtained, which takes the
relativistic effect into account. It is demonstrated that the angular frequency
of classical rotation is only valid in local approximation. The properties of
the relativistic rotation and the relativistic transverse Doppler shift are
discussed in this work
A metal–organic framework/α-alumina composite with a novel geometry for enhanced adsorptive separation
The development of a metal–organic framework/α-alumina composite leads to a novel concept: efficient adsorption occurs within a plurality of radial micro-channels with no loss of the active adsorbents during the process. This composite can effectively remediate arsenic contaminated water producing potable water recovery, whereas the conventional fixed bed requires eight times the amount of active adsorbents to achieve a similar performance
Theoretical studies of the local structures and EPR parameters for Cu center in Cd(NH)(SO) single crystal
The electron paramagnetic resonance (EPR) parameters ( factors and
the hyperfine structure constants , ) are
interpreted by using the perturbation formulae for a ion in
rhombically ({D}) elongated octahedra. In the calculated formulae, the
crystal field parameters are set up from the superposition model, and the
contribution to the EPR parameters from the admixture of -orbitals in the
ground state wave function of the Cu ion was taken into account. Based
on the calculation, local structural parameters of the impurity Cu
center in Cd(NH)(SO) (CAS) crystal were obtained
(i.e., {\AA}, {\AA},
{\AA}). The theoretical EPR parameters based on the
above Cu-O bond lengths in CAS crystal show a good agreement with
the observed values. The results are discussed.Comment: 5 page
Settling Some Open Problems on 2-Player Symmetric Nash Equilibria
Over the years, researchers have studied the complexity of several decision
versions of Nash equilibrium in (symmetric) two-player games (bimatrix games).
To the best of our knowledge, the last remaining open problem of this sort is
the following; it was stated by Papadimitriou in 2007: find a non-symmetric
Nash equilibrium (NE) in a symmetric game. We show that this problem is
NP-complete and the problem of counting the number of non-symmetric NE in a
symmetric game is #P-complete.
In 2005, Kannan and Theobald defined the "rank of a bimatrix game"
represented by matrices (A, B) to be rank(A+B) and asked whether a NE can be
computed in rank 1 games in polynomial time. Observe that the rank 0 case is
precisely the zero sum case, for which a polynomial time algorithm follows from
von Neumann's reduction of such games to linear programming. In 2011, Adsul et.
al. obtained an algorithm for rank 1 games; however, it does not solve the case
of symmetric rank 1 games. We resolve this problem
Distribution of Crude Fat for a Halophyte (\u3ci\u3eSuaeda glauca\u3c/i\u3e) Growing in the Songnen Grassland
Measurement of flow volume in the presence of reverse flow with ultrasound speckle decorrelation
Direct measurement of volumetric flow rate in the cardiovascular system with ultrasound is valuable but has been a challenge because most current 2-D flow imaging techniques are only able to estimate the flow velocity in the scanning plane (in-plane). Our recent study demonstrated that high frame rate contrast ultrasound and speckle decorrelation (SDC) can be used to accurately measure the speed of flow going through the scanning plane (through-plane). The volumetric flow could then be calculated by integrating over the luminal area, when the blood vessel was scanned from the transverse view. However, a key disadvantage of this SDC method is that it cannot distinguish the direction of the through-plane flow, which limited its applications to blood vessels with unidirectional flow. Physiologic flow in the cardiovascular system could be bidirectional due to its pulsatility, geometric features, or under pathologic situations. In this study, we proposed a method to distinguish the through-plane flow direction by inspecting the flow within the scanning plane from a tilted transverse view. This method was tested on computer simulations and experimental flow phantoms. It was found that the proposed method could detect flow direction and improved the estimation of the flow volume, reducing the overestimation from over 100% to less than 15% when there was flow reversal. This method showed significant improvement over the current SDC method in volume flow estimation and can be applied to a wider range of clinical applications where bidirectional flow exists
The influence of twin boundaries on the Flux Line Lattice structure in YBaCuO: a study by Small Angle Neutron Scattering
The influence of Twin Boundaries (TB) on the Flux Line Lattice(FLL) structure
was investigated by Small Angle Neutron Scattering (SANS). YBaCuO single
crystals possessing different TB densities were studied. The SANS experiments
show that the TB strongly modify the structure of the FLL. The flux lines
meander as soon as the magnetic field makes an angle with the TB direction.
According to the value of this angle but also to the ratio of the flux lines
density over the TB density, one observes that the FLL exhibits two different
unit cells in the plane perpendicular to the magnetic field. One is the
classical hexagonal and anisotropic cell while the other is affected by an
additional deformation induced by the TB. We discuss a possible relation
between this deformation and the increase of the critical current usually
observed in heavily twinned samples.Comment: accepted for publication in Phys Rev
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