1,817 research outputs found
Multiple Staggered Mesh Ewald: Boosting the Accuracy of the Smooth Particle Mesh Ewald Method
The smooth particle mesh Ewald (SPME) method is the standard method for
computing the electrostatic interactions in the molecular simulations. In this
work, the multiple staggered mesh Ewald (MSME) method is proposed to boost the
accuracy of the SPME method. Unlike the SPME that achieves higher accuracy by
refining the mesh, the MSME improves the accuracy by averaging the standard
SPME forces computed on, e.g. , staggered meshes. We prove, from theoretical
perspective, that the MSME is as accurate as the SPME, but uses times
less mesh points in a certain parameter range. In the complementary parameter
range, the MSME is as accurate as the SPME with twice of the interpolation
order. The theoretical conclusions are numerically validated both by a uniform
and uncorrelated charge system, and by a three-point-charge water system that
is widely used as solvent for the bio-macromolecules
Spin Hydrodynamic Generation in the Charged Subatomic Swirl
Recently there have been significant interests in the spin hydrodynamic
generation phenomenon from multiple disciplines of physics. Such phenomenon
arises from global polarization effect of microscopic spin by macroscopic fluid
rotation and is expected to occur in the hot quark-gluon fluid (the ``subatomic
swirl'') created in relativistic nuclear collisions. This was indeed discovered
in experiments which however revealed an intriguing puzzle: a polarization
difference between particles and anti-particles. We suggest a novel application
of a general connection between rotation and magnetic field: a magnetic field
naturally arises along the fluid vorticity in the charged subatomic swirl. We
establish this mechanism as a new way for generating long-lived in-medium
magnetic field in heavy ion collisions. Due to its novel feature, this new
magnetic field provides a nontrivial explanation to the puzzling observation of
a difference in spin hydrodynamic generation for particles and anti-particles
in heavy ion collisions.Comment: 10 pages, 3 figures, title changed according to published versio
Operations capability, productivity and business performance: the moderating effect of environmental dynamism
Purpose β The purpose of this study is to investigate the relationships between operations capability, productivity and business performance in the context of environmental dynamism. Design/methodology/approach β A proposed conceptual framework grounded in the resourcebased view (RBV) and dynamic capability view (DCV) is analysed using archival data from 193 automakers in the UK.
Findings β The results show that operations capability, as an important dynamic capability, has a significant positive effect on productivity, which in turn leads to improved business performance. The results also suggest that productivity fully mediates the relationship between operations capability and business performance, and that environmental dynamism significantly moderates the relationship between operations capability and productivity.
Practical implications β The research findings provide practical insights that will help managers develop operations capability to gain greater productivity and business performance in a dynamic environment
- β¦