Strong Interference Effects Research Articles

Graph theoretical approach to functional connectivity in prefrontal cortex via fNIRS.

Functional near-infrared spectroscopy (fNIRS) has been proposed as an affordable, fast, and robust alternative to many neuroimaging modalities yet it still has long way to go to be adapted in the clinic. One request from the clinicians has been the delivery of a simple and straightforward metric (a so-called biomarker) from the vast amount of data a multichannel fNIRS system provides. We propose a simple-straightforward signal processing algorithm derived from [Formula: see text] data collected during a modified version of the color-word matching Stroop task that consists of three different conditions. The algorithm starts with a wavelet-transform-based preprocessing, then uses partial correlation analysis to compute the functional connectivity matrices at each condition and then computes the global efficiency values. To this end, a continuous wave 16 channels fNIRS device (ARGES Cerebro, Hemosoft Inc., Turkey) was used to measure the changes in [Formula: see text] concentrations from 12 healthy volunteers. We have considered 10% of strongest connections in each network. A strong Stroop interference effect was found between the incongruent against neutral condition ([Formula: see text]) while a similar significance was observed for the global efficiency values decreased from neutral to congruent to incongruent conditions [[Formula: see text], [Formula: see text]]. The findings bring us closer to delivering a biomarker derived from fNIRS data that can be reliably and easily adopted by the clinicians.

The electro-optic mechanism and infrared switching dynamic of the hybrid multilayer VO2/Al:ZnO heterojunctions

Active and widely controllable phase transition optical materials have got rapid applications in energy-efficient electronic devices, field of meta-devices and so on. Here, we report the optical properties of the vanadium dioxide (VO2)/aluminum-doped zinc oxide (Al:ZnO) hybrid n-n type heterojunctions and the corresponding electro-optic performances of the devices. Various structures are fabricated to compare the discrepancy of the optical and electrical characteristics. It was found that the reflectance spectra presents the wheel phenomenon rather than increases monotonically with temperature at near-infrared region range. The strong interference effects was found in the hybrid multilayer heterojunction. In addition, the phase transition temperature decreases with increasing the number of the Al:ZnO layer, which can be ascribed to the electron injection to the VO2 film from the Al:ZnO interface. Affected by the double layer Al:ZnO, the abnormal Raman vibration mode was presented in the insulator region. By adding the external voltage on the Al2O3/Al:ZnO/VO2/Al:ZnO, Al2O3/Al:ZnO/VO2 and Al2O3/VO2/Al:ZnO thin-film devices, the infrared optical spectra of the devices can be real-time manipulated by an external voltage. The main effect of joule heating and assistant effect of electric field are illustrated in this work. It is believed that the results will add a more thorough understanding in the application of the VO2/transparent conductive film device.

Plasmonics and Antenna Effect Mediated Super Absorption in Ultrathin Film via Core/Shell Design

The conventionally low-absorbing ultrathin film is recently shown to obtain a high absorption via a strong optical interference effect by coating the highly absorbing film onto a metal layer. In this letter, through finite-element simulation and modal analysis, we report that the optical performance of an ultrathin semiconductor film can be significantly improved by further nanostructuring the ultrathin semiconductor film. Through wrapping the film onto a metallic nanowire in either lying or vertical configuration, a high dielectric resonance antenna effect and a strong plasmonic resonance can be excited simultaneously, which enables an extremely high and broadband optical absorption. Especially, with introducing the vertical metal-core/semiconductor-shell design, the peak absorption can be up to >300% under an extremely high field-confinement effect, leading to an integrated photocurrent density, which can be 25 times higher than that of the planar system. The proposed scheme is useful for the realization of compact, low-cost, and highly absorbing systems for photon absorbing, solar-energy harvesting, and photodetection applications.

Magneto-optical Kerr rotation and color in ultrathin lossy dielectric

Ultra-thin optical coating comprising nanometer-thick silicon absorbing films on iron substrates can display strong optical interference effects. A resonance peak of longitudinal Kerr rotation with the silicon thickness of was found at the wavelength of 660 nm. The optical properties of silicon thin films were well controlled by the sputtering power. Non-iridescence color exhibition and Kerr rotation enhancement can be manipulated and encoded individually.

Analysis of interference effects on torsional moment between two high-rise buildings based on pressure and flow field measurement

Wind induced interference effects between high-rise buildings have become quite important in structural engineering in modern cities recently due to the close proximity of high-rise buildings. In this study, the wind induced interference effects on the torsional load on two adjacent high-rise buildings are studied through wind tunnel experiment. Two different sectional shapes of high-rise buildings are studied and four kinds of arrangements are investigated. Existing interference factors are adopted to quantitatively evaluate the interference effects. Results show that the mean torsion on a building when under interfered conditions can be tripled that for the isolated case. Although the interference effect on the fluctuating torsion is not as strong as on the mean torsion, the interference factor can be as large as 1.6. The extreme torsion under interference effects is also higher at 1.8 times that of the isolated case. With the help of pressure measurement on the principal building and the flow field information around the buildings, the underlying mechanisms of some typical cases which exhibit strong interference effects are discussed. Results show that the intricate flow field around the principal building with the presence of an interfering building is the main case of the large torsion it experiences.

Narrowing of Broad Band Light Emitted from a SSI-LED

The broad band light emitted from a SSI-LED has been narrowed down with the addition of a PECVD a-Si:H or SiNx thin film light filter. The a-Si:H film absorbs the light in the short wavelength range beyond which its transmittance increases with the increase of wavelength. The SiNx film shows strong interference effect related to its refractive index and thickness. The light filtering effect of both thin films can last for a long period of time in air. There are many possible applications of the narrow band light emitted from the thin film coated and IC-compatible SSI-LED.

Subwavelength nanocavity for flexible structural transmissive color generation with a wide viewing angle

We present a high angular tolerant structural coloration based on strong interference effects in a nanocavity patterned at a subwavelength scale on a flexible substrate. The structural colors, fabricated over a large area by nanoimprint lithography, feature a non-iridescent performance over a wide angle of incidence up to 60°, which is of great importance to various applications, such as imaging sensors and colored display systems. In addition to the non-iridescence, the transmissive colors of the proposed structure, simply consisting of triple layers, can be tuned with ease by altering a duty cycle of nanostructures, thus enabling the creation of individual RGB colors in a pixel unit via a facile one-step approach. Moreover, it is confirmed that their performances remain unchanged to the 10 mm bending radius condition, and the encapsulation effects of a polymer material on their optical properties are investigated for practical usage. The presented strategy could provide a new avenue for achieving improved efficiency and desired functionality, thereby opening the door to many potential applications, including anti-counterfeit tagging, imaging sensor systems, and color e-paper displays.

Driving and Multitasking: The Good, the Bad, and the Dangerous.

Previous research has shown that multitasking can have a positive or a negative influence on driving performance. The aim of this study was to determine how the interaction between driving circumstances and cognitive requirements of secondary tasks affect a driver's ability to control a car. We created a driving simulator paradigm where participants had to perform one of two scenarios: one with no traffic in the driver's lane, and one with substantial traffic in both lanes, some of which had to be overtaken. Four different secondary task conditions were combined with these driving scenarios. In both driving scenarios, using a tablet resulted in the worst, most dangerous, performance, while passively listening to the radio or answering questions for a radio quiz led to the best driving performance. Interestingly, driving as a single task did not produce better performance than driving in combination with one of the radio tasks, and even tended to be slightly worse. These results suggest that drivers switch to internally focused secondary tasks when nothing else is available during monotonous or repetitive driving environments. This mind wandering potentially has a stronger interference effect with driving than non-visual secondary tasks.

Large area Germanium Tin nanometer optical film coatings on highly flexible aluminum substrates.

Germanium Tin (GeSn) films have drawn great interest for their visible and near-infrared optoelectronics properties. Here, we demonstrate large area Germanium Tin nanometer thin films grown on highly flexible aluminum foil substrates using low-temperature molecular beam epitaxy (MBE). Ultra-thin (10–180 nm) GeSn film-coated aluminum foils display a wide color spectra with an absorption wavelength ranging from 400–1800 nm due to its strong optical interference effect. The light absorption ratio for nanometer GeSn/Al foil heterostructures can be enhanced up to 85%. Moreover, the structure exhibits excellent mechanical flexibility and can be cut or bent into many shapes, which facilitates a wide range of flexible photonics. Micro-Raman studies reveal a large tensile strain change with GeSn thickness, which arises from lattice deformations. In particular, nano-sized Sn-enriched GeSn dots appeared in the GeSn coatings that had a thickness greater than 50 nm, which induced an additional light absorption depression around 13.89 μm wavelength. These findings are promising for practical flexible photovoltaic and photodetector applications ranging from the visible to near-infrared wavelengths.

Coverage and Rate Analysis for Limited Information Cell Association in Stochastic-Layout Cellular Networks

The complexity and uncertainty inherent in large cellular networks make the acquisition of location and channel information of all but perhaps a few neighboring network nodes (base stations (BSs)) difficult for a given user. Therefore, a cell association policy must operate with sparse information. Thus, the serving BS is proposed to be the one that provides the highest instantaneous signal-to-interference ratio (SIR) from among all BSs providing average received signal power exceeding a predetermined minimum. This policy is evaluated for the downlink of single-tier (homogeneous) and two-tier (heterogeneous) networks, and for the latter, the key advantage of the proposed policy is its capability to enable traffic offloading. Two methods to determine the minimum average signal power are given. Coverage probabilities and average rates of mobile stations in coverage are derived, accounting for path loss, multipath fading, and random locations of BSs in each tier. Analysis is verified by Monte Carlo simulations. We observe that the instantaneous SIR and average received signal power of a few BSs are sufficient to achieve the coverage corresponding to the highest SIR association, which in general requires instantaneous SIR information of a larger subset of a network. We also observe that in a two-tier network, the effect of strong interference from high-power BSs, such as macro BSs, can be limited by proper choice of minimum average received signal power for low-power BSs.

Differential evolution algorithm based photonic structure design: numerical and experimental verification of subwavelength λ/5 focusing of light.

Photonic structure designs based on optimization algorithms provide superior properties compared to those using intuition-based approaches. In the present study, we numerically and experimentally demonstrate subwavelength focusing of light using wavelength scale absorption-free dielectric scattering objects embedded in an air background. An optimization algorithm based on differential evolution integrated into the finite-difference time-domain method was applied to determine the locations of each circular dielectric object with a constant radius and refractive index. The multiobjective cost function defined inside the algorithm ensures strong focusing of light with low intensity side lobes. The temporal and spectral responses of the designed compact photonic structure provided a beam spot size in air with a full width at half maximum value of 0.19λ, where λ is the wavelength of light. The experiments were carried out in the microwave region to verify numerical findings, and very good agreement between the two approaches was found. The subwavelength light focusing is associated with a strong interference effect due to nonuniformly arranged scatterers and an irregular index gradient. Improving the focusing capability of optical elements by surpassing the diffraction limit of light is of paramount importance in optical imaging, lithography, data storage, and strong light-matter interaction.

The Importance of Interspecific Interactions on the Present Range of the Invasive Mosquito Aedes albopictus (Diptera: Culicidae) and Persistence of Resident Container Species in the United States.

Aedes albopictus (Skuse) established in the United States over 30 yr ago and quickly spread throughout the entire eastern half of the country. It has recently spread into western regions and projected climate change scenarios suggest continued expansion to the west and north. Aedes albopictus has had major impacts on, and been impacted by, a diverse array of resident mosquito species. Laying eggs at the edges of small, water-holding containers, hatched larvae develop within these containers feeding on detritus-based resources. Under limited resource conditions, Ae. albopictus has been shown to be a superior competitor to essentially all native and resident species in the United States. Adult males also mate interspecifically with at least one resident species with significant negative impacts on reproductive output for susceptible females. Despite these strong interference effects on sympatric species, competitor outcomes have been highly variable, ranging from outright local exclusion by Ae. albopictus, to apparent exclusion of Ae. albopictus in the presence of the same species. Context-dependent mechanisms that alter the relative strengths of inter- and intraspecific competition, as well as rapid evolution of satyrization-resistant females, may help explain these patterns of variable coexistence. Although there is a large body of research on interspecific interactions of Ae. albopictus in the United States, there remain substantial gaps in our understanding of the most important species interactions. Addressing these gaps is important in predicting the future distribution of this species and understanding consequences for resident species, including humans, that interact with this highly invasive mosquito.

Interference and Inhibition in Bilingual Language Comprehension: Evidence from Polish-English Interlingual Homographs.

The main goal of the present study was to explore the involvement of inhibition in resolution of cross-language activation in bilingual comprehension and a possible modulatory effect of L2 proficiency. We used a semantic relatedness judgment task in L2 English that included Polish-English interlingual homographs and English translations of the Polish homographs’ meanings. Based on previous studies using the same paradigm, we expected a strong homograph interference and inhibition of the homographs’ Polish meanings translations. In addition, we predicted that participants with lower L2 proficiency would experience greater interference and stronger inhibitory effects. The reported results confirm a strong homograph interference effect. In addition, our results indicate that the scope of inhibition generalized from the homograph’s irrelevant meaning to a whole semantic category, indicating the flexibility of the inhibitory mechanisms. Contrary to our expectations, L2 proficiency did not modulate the effects of interference and inhibition, possibly due to a relatively low variability in proficiency within our participant sample.

The role of visual and spatial working memory in forming mental models derived from survey and route descriptions.

This study examines the involvement of spatial and visual working memory (WM) in the construction of flexible spatial models derived from survey and route descriptions. Sixty young adults listened to environment descriptions, 30 from a survey perspective and the other 30 from a route perspective, while they performed spatial (spatial tapping [ST]) and visual (dynamic visual noise [DVN]) secondary tasks - believed to overload the spatial and visual working memory (WM) components, respectively - or no secondary task (control, C). Their mental representations of the environment were tested by free recall and a verification test with both route and survey statements. Results showed that, for both recall tasks, accuracy was worse in the ST than in the C or DVN conditions. In the verification test, the effect of both ST and DVN was a decreasing accuracy for sentences testing spatial relations from the opposite perspective to the one learnt than if the perspective was the same; only ST had a stronger interference effect than the C condition for sentences from the opposite perspective from the one learnt. Overall, these findings indicate that both visual and spatial WM, and especially the latter, are involved in the construction of perspective-flexible spatial models.

Spin-orbital and spin Kondo effects in parallel coupled quantum dots

Strong electron correlations and interference effects are discussed in parallel-coupled single-level and orbitally doubly degenerate quantum dots. The finite-U mean-field slave boson approach is used to study many-body effects. The analysis is carried out in a wide range of parameter space including both atomic-like and molecular-like Kondo regimes and taking into account various perturbations, like interdot tunneling, interdot interaction, mixing of the electrode channels and exchange interaction. We also discuss the influence of singularities of electronic structure and the impact of polarization of electrodes. Special attention is paid to potential spintronic applications of these systems showing how current polarization can be controlled by adjusting interference conditions and correlations by gate voltage. Simple proposals of double dot spin valve and bipolar electrically tunable spin filter are presented.

Responding to social and symbolic extrafoveal cues: cue shape trumps biological relevance

Social cues presented at visual fixation have been shown to strongly influence an observer’s attention and response selection. Here we ask whether the same holds for cues (initially) presented away from fixation, as cues are commonly perceived in natural vision. In six experiments, we show that extrafoveally presented cues with a distinct outline, such as pointing hands, rotated heads, and arrow cues result in strong cueing of responses (either to the cue itself, or a cued object). In contrast, cues without a clear outline, such as gazing eyes and direction words exert much weaker effects on participants’ responses to a target cue. We also show that distraction effects on response times are relatively weak, but that strong interference effects can be obtained by measuring mouse trajectories. Eye tracking suggests that gaze cues are slower to respond to because their direction cannot easily be perceived in extrafoveal vision. Together, these data suggest that the strength of an extrafoveal cue is determined by the shape of the cue outline, rather than its biological relevance (i.e., whether the cue is provided by another human being), and that this shape effect is due to how easily the direction of a cue can be perceived in extrafoveal vision.

Control of absorption of monolayer MoS2 thin-film transistor in one-dimensional defective photonic crystal

The light absorption and transmission of monolayer MoS2 in a flexible one-dimensional defective photonic crystal (d-1DPC) are theoretically investigated. The study shows that the strong interference effect decreases the photon density in particular areas of the microcavity. The d-1DPC can reduce light absorption of the monolayer MoS2 and enhance light transmission. The impact of monolayer MoS2 light absorption on the localization effect of the photon is investigated when the monolayer MoS2 and the organic light-emitting diode are located in the same microcavity. However, monolayer MoS2 does not reduce the emission intensity from the microcavity by regulating the position of monolayer MoS2 in the microcavity.

Orientational ordering of confined hard rods: the effect of shape anisotropy on surface ordering and capillary nematization.

We examine the ordering properties of rectangular hard rods with length L and diameter D at a single planar wall and between two parallel hard walls using the second virial density-functional theory. The theory is implemented in the three-state Zwanzig approximation, where only three mutually perpendicular directions are allowed for the orientations of hard rods. The effect of varying shape anisotropy is examined at L/D=10,15,and20. In contact with a single hard wall, the density profiles show planar ordering, damped oscillatory behavior, and a wall-induced surface ordering transition below the coexisting isotropic density of a bulk isotropic-nematic (I-N) phase transition. Upon approaching the coexisting isotropic density, the thickness of the nematic film diverges logarithmically, i.e., the nematic wetting is complete for any shape anisotropy. In the case of confinement between two parallel hard walls, it is found that the continuous surface ordering transition depends strongly on the distance between confining walls H for H<L, while it depends weakly on H for H>L. The minimal density at which a surface ordering transition can be realized is located at around H∼2D for all studied shape anisotropies due to the strong interference effect between the two hard walls. The first-order I-N phase transition of the bulk system becomes a surface ordered isotropic I_{B} to capillary nematic N_{B} phase transition in the slit pore. This first-order I_{B}-N_{B} transition weakens with decreasing pore width and terminates in a critical point for all studied shape anisotropies.

Interference in the processing of adjunct control

Recent research on the memory operations used in language comprehension has revealed a selective profile of interference effects during memory retrieval. Dependencies such as subject–verb agreement show strong facilitatory interference effects from structurally inappropriate but feature-matching distractors, leading to illusions of grammaticality (Pearlmutter et al., 1999; Wagers et al., 2009; Dillon et al., 2013). In contrast, dependencies involving reflexive anaphors are generally immune to interference effects (Sturt, 2003; Xiang et al., 2009; Dillon et al., 2013). This contrast has led to the proposal that all anaphors that are subject to structural constraints are immune to facilitatory interference. Here we use an animacy manipulation to examine whether adjunct control dependencies, which involve an interpreted anaphoric relation between a null subject and its licensor, are also immune to facilitatory interference effects. Our results show reliable facilitatory interference in the processing of adjunct control dependencies, which challenges the generalization that anaphoric dependencies as a class are immune to such effects. To account for the contrast between adjunct control and reflexive dependencies, we suggest that variability within anaphora could reflect either an inherent primacy of animacy cues in retrieval processes, or differential degrees of match between potential licensors and the retrieval probe.

Doping- and interference-free measurement of I2D/IG in suspended monolayer graphene blisters

We report on strong interference effects on the ratio of the integrated intensities of the Raman 2D- and G-mode features (herein denoted ) in suspended graphene monolayers. Free from substrate-induced doping and residual charge inhomogeneity, suspended samples are an ideal platform to study the intrinsic properties of graphene. Here, we demonstrate that , measured on a pressurized suspended graphene blister, depends very sensitively on the distance between the bulged graphene membrane and the underlying substrate. The data obtained on three different samples are fit to theoretically predicted Raman enhancement factors and allow to extract an intrinsic, i.e., doping- and interference-free, value of for undoped, unscreened graphene at a laser photon energy of .