40,069 research outputs found
Monte-Carlo Simulations of Spin-Crossover Phenomena Based on a Vibronic Ising-like Model with Realistic Parameters
Materials with spin-crossover (SCO) properties hold great potentials in
information storage and therefore have received a lot of concerns in the recent
decades. The hysteresis phenomena accompanying SCO is attributed to the
intermolecular cooperativity whose underlying mechanism may have a vibronic
origin. In this work, a new vibronic Ising-like model in which the elastic
coupling between SCO centers is included by considering harmonic stretching and
bending (SAB) interactions is proposed and solved by Monte Carlo simulations.
The key parameters in the new model, and , corresponding to the
elastic constant of the stretching and bending mode, respectively, can be
directly related to the macroscopic bulk and shear modulus of the material in
study, which can be readily estimated either based on experimental measurements
or first-principles calculations. The convergence issue in the MC simulations
of the thermal hysteresis has been carefully checked, and it was found that the
stable hysteresis loop can be more readily obtained when using the SAB model
compared to that using the Wajnflasz-Pick model. Using realistic parameters
estimated based on first-principles calculations of a specific polymeric
coordination SCO compound, [Fe(pz)Pt(CN)]2HO,
temperature-induced hysteresis and pressure effects on SCO phenomena are
simulated successfully.Comment: 8 pages, 8 figure
Microstructural Characterization of Shrouded Plasma-Sprayed Titanium Coatings
Titanium and its alloys are often used for corrosion protection because they are able to
offer high chemical resistance against various corrosive media. In this paper, shrouded plasma spray
technology was applied to produce titanium coatings. A solid shroud with an external shrouding
gas was used to plasma spray titanium powder feedstock with aim of reducing the oxide content
in the as-sprayed coatings. The titanium coatings were assessed by optical microscope, scanning
electron microscopy, X-ray diffraction, LECO combustion method and Vickers microhardness testing.
The results showed that the presence of the shroud and the external shrouding gas led to a dense
microstructure with a low porosity in the plasma-sprayed titanium coatings. The oxygen and nitrogen
contents in the titanium coating were kept at a low level due to the shielding effect of the shroud
attachment and the external shrouding gas. The dominant phase in the shrouded titanium coatings
was mainly composed of α-Ti phase, which was very similar to the titanium feedstock powders.
The shrouded plasma-sprayed titanium coatings had a Vickers microhardness of 404.2 ± 103.2 HV
Online Filter Clustering and Pruning for Efficient Convnets
Pruning filters is an effective method for accelerating deep neural networks
(DNNs), but most existing approaches prune filters on a pre-trained network
directly which limits in acceleration. Although each filter has its own effect
in DNNs, but if two filters are the same with each other, we could prune one
safely. In this paper, we add an extra cluster loss term in the loss function
which can force filters in each cluster to be similar online. After training,
we keep one filter in each cluster and prune others and fine-tune the pruned
network to compensate for the loss. Particularly, the clusters in every layer
can be defined firstly which is effective for pruning DNNs within residual
blocks. Extensive experiments on CIFAR10 and CIFAR100 benchmarks demonstrate
the competitive performance of our proposed filter pruning method.Comment: 5 pages, 4 figure
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