354 research outputs found
The effect of Cr impurity to superconductivity in electron-doped BaFe2-xNixAs2
We use transport and magnetization measurements to study the effect of
Cr-doping to the phase diagram of the electron-doped superconducting
BaFe2-xNixAs2 iron pnictides. In principle, adding Cr to electron-doped
BaFe2-xNixAs2 should be equivalent to the effect of hole-doping. However, we
find that Cr doping suppresses superconductivity via impurity effect, while not
affecting the normal state resistivity above 100 K. We establish the phase
diagram of Cr-doped BaFe2-x-yNixCryAs2 iron pnictides, and demonstrate that
Cr-doping near optimal superconductivity restore the long-range
antiferromagnetic order suppressed by superconductivity.Comment: 10 pages, 5 figure
Generalized Completed Local Binary Patterns for Time-Efficient Steel Surface Defect Classification
© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted ncomponent of this work in other works.Efficient defect classification is one of the most important preconditions to achieve online quality inspection for hot-rolled strip steels. It is extremely challenging owing to various defect appearances, large intraclass variation, ambiguous interclass distance, and unstable gray values. In this paper, a generalized completed local binary patterns (GCLBP) framework is proposed. Two variants of improved completed local binary patterns (ICLBP) and improved completed noise-invariant local-structure patterns (ICNLP) under the GCLBP framework are developed for steel surface defect classification. Different from conventional local binary patterns variants, descriptive information hidden in nonuniform patterns is innovatively excavated for the better defect representation. This paper focuses on the following aspects. First, a lightweight searching algorithm is established for exploiting the dominant nonuniform patterns (DNUPs). Second, a hybrid pattern code mapping mechanism is proposed to encode all the uniform patterns and DNUPs. Third, feature extraction is carried out under the GCLBP framework. Finally, histogram matching is efficiently accomplished by simple nearest-neighbor classifier. The classification accuracy and time efficiency are verified on a widely recognized texture database (Outex) and a real-world steel surface defect database [Northeastern University (NEU)]. The experimental results promise that the proposed method can be widely applied in online automatic optical inspection instruments for hot-rolled strip steel.Peer reviewe
Clinical Assistant Diagnosis for Electronic Medical Record Based on Convolutional Neural Network
Automatically extracting useful information from electronic medical records
along with conducting disease diagnoses is a promising task for both clinical
decision support(CDS) and neural language processing(NLP). Most of the existing
systems are based on artificially constructed knowledge bases, and then
auxiliary diagnosis is done by rule matching. In this study, we present a
clinical intelligent decision approach based on Convolutional Neural
Networks(CNN), which can automatically extract high-level semantic information
of electronic medical records and then perform automatic diagnosis without
artificial construction of rules or knowledge bases. We use collected 18,590
copies of the real-world clinical electronic medical records to train and test
the proposed model. Experimental results show that the proposed model can
achieve 98.67\% accuracy and 96.02\% recall, which strongly supports that using
convolutional neural network to automatically learn high-level semantic
features of electronic medical records and then conduct assist diagnosis is
feasible and effective.Comment: 9 pages, 4 figures, Accepted by Scientific Report
Longitudinal spin excitations and magnetic anisotropy in antiferromagnetically ordered BaFe2As2
We report on a spin-polarized inelastic neutron scattering study of spin
waves in the antiferromagnetically ordered state of BaFe2As2. Three distinct
excitation components are identified, with spins fluctuating along the c-axis,
perpendicular to the ordering direction in the ab-plane, and parallel to the
ordering direction. While the first two "transverse" components can be
described by a linear spin-wave theory with magnetic anisotropy and inter-layer
coupling, the third "longitudinal" component is generically incompatible with
the local moment picture. It points towards a contribution of itinerant
electrons to the magnetism already in the parent compound of this family of
Fe-based superconductors.Comment: 4 pages, 4 figures, plus Supplemental Materia
Nematic crossover in BaFeAs under uniaxial stress
Raman scattering can detect spontaneous point-group symmetry breaking without
resorting to single-domain samples. Here we use this technique to study
, the parent compound of the "122" Fe-based
superconductors. We show that an applied compression along the Fe-Fe direction,
which is commonly used to produce untwinned orthorhombic samples, changes the
structural phase transition at temperature into a crossover
that spans a considerable temperature range above . Even in
crystals that are not subject to any applied force, a distribution of
substantial residual stress remains, which may explain phenomena that are
seemingly indicative of symmetry breaking above . Our results
are consistent with an onset of spontaneous nematicity only below
.Comment: 4 pages, 4 figure
- …