4,560 research outputs found
Photon-assisted electron transmission resonance through a quantum well with spin-orbit coupling
Using the effective-mass approximation and Floquet theory, we study the
electron transmission over a quantum well in semiconductor heterostructures
with Dresselhaus spin-orbit coupling and an applied oscillation field. It is
demonstrated by the numerical evaluations that Dresselhaus spin-orbit coupling
eliminates the spin degeneracy and leads to the splitting of asymmetric
Fano-type resonance peaks in the conductivity. In turn, the splitting of
Fano-type resonance induces the spin- polarization-dependent electron-current.
The location and line shape of Fano-type resonance can be controlled by
adjusting the oscillation frequency and the amplitude of external field as
well. These interesting features may be a very useful basis for devising
tunable spin filters.Comment: 10pages,4figure
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1458 EMT-inhibiting transcription factor Ovol2 regulates directional cell migration and proliferation in adult skin epithelia
Tunnel splitting and quantum phase interference in biaxial ferrimagnetic particles at excited states
The tunneling splitting in biaxial ferrimagnetic particles at excited states
with an explicit calculation of the prefactor of exponent is obtained in terms
of periodic instantons which are responsible for tunneling at excited states
and is shown as a function of magnetic field applied along an arbitrary
direction in the plane of hard and medium axes. Using complex time
path-integral we demonstrate the oscillation of tunnel splitting with respect
to the magnitude and the direction of the magnetic field due to the quantum
phase interference of two tunneling paths of opposite windings . The
oscillation is gradually smeared and in the end the tunnel splitting
monotonously increases with the magnitude of the magnetic field when the
direction of the magnetic field tends to the medium axis. The oscillation
behavior is similar to the recent experimental observation with Fe
molecular clusters. A candidate of possible experiments to observe the effect
of quantum phase interference in the ferrimagnetic particles is proposed.Comment: 15 pages, 5 figures, acceptted to be pubblished in Physical Review
In-Plane Magnetic Anisotropy In RF Sputtered Fe-N Thin Films
We have fabricated Fe(N) thin films with varied N2 partial pressure and
studied the microstructure, morphology, magnetic properties and resistivity by
using X-ray diffraction, atomic force microscopy, transmission electron
microscopy, vibrating-sample magnetometer and angle-resolved M-H hysteresis
Loop tracer and standard four-point probe method. In the presence of low N2
partial pressure, Fe(N) films showed a basic bcc a-Fe structure with a
preferred (110) texture. A variation of in-plane magnetic anisotropy of the
Fe(N) films was observed with the changing of N component. The evolution of
in-plane anisotropy in the films was attributed to the directional order
mechanism. Nitrogen atoms play an important role in refining the a-Fe grains
and inducing uniaxial anisotropy.Comment: 11 pages, 6 figure
A brain-region-based meta-analysis method utilizing the Apriori algorithm
Background: Brain network connectivity modeling is a crucial method for studying the brain's cognitive functions. Meta-analyses can unearth reliable results from individual studies. Meta-analytic connectivity modeling is a connectivity analysis method based on regions of interest (ROIs) which showed that meta-analyses could be used to discover brain network connectivity. Results: In this paper, we propose a new meta-analysis method that can be used to find network connectivity models based on the Apriori algorithm, which has the potential to derive brain network connectivity models from activation information in the literature, without requiring ROIs. This method first extracts activation information from experimental studies that use cognitive tasks of the same category, and then maps the activation information to corresponding brain areas by using the automatic anatomical label atlas, after which the activation rate of these brain areas is calculated. Finally, using these brain areas, a potential brain network connectivity model is calculated based on the Apriori algorithm. The present study used this method to conduct a mining analysis on the citations in a language review article by Price (Neuroimage 62(2):816-847, 2012). The results showed that the obtained network connectivity model was consistent with that reported by Price. Conclusions: The proposed method is helpful to find brain network connectivity by mining the co-activation relationships among brain regions. Furthermore, results of the co-activation relationship analysis can be used as a priori knowledge for the corresponding dynamic causal modeling analysis, possibly achieving a significant dimension-reducing effect, thus increasing the efficiency of the dynamic causal modeling analysis
Parent-adolescent attachment and peer attachment associated with Internet Gaming Disorder: a longitudinal study of first-year undergraduate students
Background and aims: Given that Internet Gaming Disorder (IGD) has tentatively been included in DSM-5 as a psychiatric disorder, it is important that the effect of parental and peer attachment in the development of IGD is further explored.
Methods: Utilizing a longitudinal design, this study investigated the bidirectional association between perceived Q1 parent-adolescent attachment, peer attachment, and IGD among 1,054 first-year undergraduate students (58.8% female). The students provided demographic information (e.g., age, gender) and were assessed using the nine-item Internet Gaming Disorder Scale and the Inventory of Parent and Peer Attachment. Assessments occurred three times, six months apart (October 2017; April 2018; October 2018).
Results: Cross-lagged panel models suggested that IGD weakly predicted subsequent mother attachment but significantly negatively predicted father attachment. However, father and mother attachment could not predict subsequent IGD. Moreover, peer attachment has bidirectional association with IGD. Further, the model also demonstrated stable crosssectional negative correlations between attachment and IGD across all three assessments.
Discussion and conclusions: The findings of the present study did not show a bidirectional association between parental attachment and IGD, but they did show a negative bidirectional association between peer attachment and IGD. The results suggested previous cross-sectional associations between IGD and attachment, with larger links among males than females at the first measurement point. We found that peer attachment could negatively predict subsequent IGD, which indicates that peer attachment plays an important role in preventing addictive gaming behaviors for university students
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