keyword
MENU ▼
Read by QxMD icon Read
search

wave reflection

keyword
https://www.readbyqxmd.com/read/28437985/scattering-of-surface-plasmon-polaritons-at-a-planar-interface-by-an-embedded-dielectric-nanocube
#1
Seojun Lee, Hyungchae Kim, Jongcheon Lee, Changsoon Kim
We investigate scattering of surface plasmon polaritons (SPPs) at a planar metal-dielectric interface by a dielectric nanocube embedded in the metal layer using finite element method-based simulations. The scattering characteristics of the embedded nanocube, such as the scattering and absorption cross sections, far-field scattering patterns, reflectance, and transmittance, are calculated as functions of the wavelength of the incident SPP waves in the visible range. The main features of the characteristics are explained in connection with the excitation of plasmonic eigenmodes of the embedded nanocube...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437936/ultra-thin-and-high-efficiency-graphene-metasurface-for-tunable-terahertz-wave-manipulation
#2
Zhen Liu, Benfeng Bai
We propose a type of ultra-thin metasurfaces composed of rectangular graphene patches supporting orthogonal plasmonic resonances, which can work in transmission or reflection modes for dynamic terahertz wavefront manipulation with high polarization conversion ratio. By controlling the response of each patch via electrical biasing, the phase of the output wave can be tuned in a wide range over 180° while keeping its amplitude high and relatively stable. We demonstrate several functional devices based on such metasurfaces: a linear polarization converter with nearly 100% polarization conversion ratio, a switchable anomalous wave deflection device, and a dual-polarity focusing mirror with the focal spot tunable in both the transversal and longitudinal directions...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437933/optical-wave-parameters-for-spatially-dispersive-and-anisotropic-nanomaterials
#3
Andriy Shevchenko, Markus Nyman, Ville Kivijärvi, Matti Kaivola
Spatial dispersion is an intriguing property of essentially all nanostructured optical media. In particular, it makes optical waves with equal frequencies and polarizations have different wavelengths, if they propagate in different directions. This can offer new approaches to control light radiation and propagation. Spatially dispersive nanomaterials, such as metamaterials, are often treated in terms of wave parameters, such as refractive index and impedance retrieved from reflection and transmission coefficients of the material at each incidence angle...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28436833/proactive-control-in-early-and-middle-childhood-an-erp-study
#4
Sarah Elke, Sandra A Wiebe
Children experience important cognitive control improvements in the transition to school. This study examined 4-5-year-olds' (n=17) and 7-8-year-olds' (n=22) ability to proactively deploy cognitive control. Children performed a cued task-switching paradigm presenting them with a cue indicating which attribute, color or shape, they should use to sort the upcoming stimulus. Following both cue and stimulus, we analyzed two event-related potentials: the P2 and P3, positive peaks reflecting sensory and attentional components of cognitive control, respectively...
April 14, 2017: Developmental Cognitive Neuroscience
https://www.readbyqxmd.com/read/28434717/relative-genetic-and-environmental-contributions-to-variations-in-human-retinal-electrical-responses-quantified-in-a-twin-study
#5
Taha Bhatti, Ambreen Tariq, Ting Shen, Katie M Williams, Christopher J Hammond, Omar A Mahroo
PURPOSE: To estimate heritability of parameters of human retinal electrophysiology and to explore which parameters change with age. DESIGN: Prospective, classic twin study. PARTICIPANTS: Adult monozygotic and dizygotic twin pairs recruited from the TwinsUK cohort. METHODS: Electroretinogram responses were recorded using conductive fiber electrodes in response to stimuli incorporating standards set by the International Society for the Clinical Electrophysiology of Vision...
April 20, 2017: Ophthalmology
https://www.readbyqxmd.com/read/28433810/generation-mechanism-of-nonlinear-ultrasonic-lamb-waves-in-thin-plates-with-randomly-distributed-micro-cracks
#6
Youxuan Zhao, Feilong Li, Peng Cao, Yaolu Liu, Jianyu Zhang, Shaoyun Fu, Jun Zhang, Ning Hu
Since the identification of micro-cracks in engineering materials is very valuable in understanding the initial and slight changes in mechanical properties of materials under complex working environments, numerical simulations on the propagation of the low frequency S0 Lamb wave in thin plates with randomly distributed micro-cracks were performed to study the behavior of nonlinear Lamb waves. The results showed that while the influence of the randomly distributed micro-cracks on the phase velocity of the low frequency S0 fundamental waves could be neglected, significant ultrasonic nonlinear effects caused by the randomly distributed micro-cracks was discovered, which mainly presented as a second harmonic generation...
April 12, 2017: Ultrasonics
https://www.readbyqxmd.com/read/28432306/simple-rectangular-gratings-as-a-near-field-anti-reflection-pattern-for-gasb-tpv-cells
#7
Haitong Yu, Dong Liu, Zhen Yang, Yuanyuan Duan
We show theoretically that 2D rectangular gratings on the surface of GaSb can serve as an "anti-reflection" pattern for nano-gap thermophotovoltaic (TPV) devices, which significantly enhances near-field radiative flux from the emitter to a GaSb cell, thus improving output power and conversion efficiency. The system in this study is a 200-nm gap TPV power generation system with a planar infrared plasmonic emitter and GaSb cell. Rigorous coupled-wave analysis is used to calculate the spectral near-field radiative flux involving periodic structures...
April 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28430249/study-of-a-reflection-grating-used-in-littrow-mount
#8
D M Capps
The near and far fields of a finite conductivity metallic grating with symmetrical triangular facets, used in Littrow mount, are studied. A new Green's function approach, based on the Hertz vector, is introduced and used to propagate throughout a two-dimensional domain. The field quantity of primary interest is Poynting's vector; however, the stored power is also calculated. In assessing the fields generated by the propagator, a quasi-periodic dependence of output characteristics on the grating depth to period ratio, discussed in the literature, is also found in the present study...
April 20, 2017: Applied Optics
https://www.readbyqxmd.com/read/28429601/later-life-preparation-patterns-on-depression-among-korean-baby-boom-generations
#9
Seok In Nam, Junpyo Kim, Jimin Shin, Arram Yim
The aim of this study was to examine the later-life preparation pattern of Korean baby boomers and its effect on depression. Using the fourth wave of Korean Retirement and Income Study, later-life preparation was measured by economic, physical, and psychological preparation, and leisure, and family relationship satisfaction. The data analysis included latent class analysis, correlations, multiple logistic regression, and analysis of variance. Later-life patterns of Korean baby boomers were classified as high-level (35...
January 1, 2017: International Journal of Aging & Human Development
https://www.readbyqxmd.com/read/28429003/electrochemical-plasmonic-metamaterials-towards-fast-electro-tuneable-reflecting-nanoshutters
#10
Debabrata Sikdar, Alwin Bucher, Cristian Zagar, Alexei A Kornyshev
Self-assembling arrays of metallic nanoparticles at liquid|liquid or liquid|solid interfaces could deliver new platforms for tuneable optical systems. Such systems can switch between very-high and very-low reflectance states upon assembly and disassembly of nanoparticles at the interface, respectively. This encourages creation of electro-variably reversible mirror/window nanoplasmonic devices. However, the response time of these systems is usually limited by the rate-of-diffusion of the nanoparticles in the liquid, towards the interface and back...
April 21, 2017: Faraday Discussions
https://www.readbyqxmd.com/read/28425737/time-varying-and-time-invariant-dimensions-of-depression-in-children-and-adolescents-implications-for-cross-informant-agreement
#11
David A Cole, Joan M Martin, Farrah M Jacquez, Jane M Tram, Rachel Zelkowitz, Elizabeth A Nick, Jason D Rights
The longitudinal structure of depression in children and adolescents was examined by applying a Trait-State-Occasion structural equation model to 4 waves of self, teacher, peer, and parent reports in 2 age groups (9 to 13 and 13 to 16 years old). Analyses revealed that the depression latent variable consisted of 2 longitudinal factors: a time-invariant dimension that was completely stable over time and a time-varying dimension that was not perfectly stable over time. Different sources of information were differentially sensitive to these 2 dimensions...
April 20, 2017: Journal of Abnormal Psychology
https://www.readbyqxmd.com/read/28423867/high-efficiency-low-power-consumption-dfb-quantum-cascade-lasers-without-lateral-regrowth
#12
Zhi-Wei Jia, Li-Jun Wang, Jin-Chuan Zhang, Feng-Qi Liu, Yu-Hong Zhou, Dong-Bo Wang, Xue-Feng Jia, Ning Zhuo, Jun-Qi Liu, Shen-Qiang Zhai, Zhan-Guo Wang
Very low power-consumption distributed feedback (DFB) quantum cascade lasers (QCLs) at the wavelength around 4.9 μm were fabricated by conventional process without lateral regrowth of InP:Fe or using sidewall grating. Benefitted from the optimized materials and low waveguide loss, very low threshold current density of 0.5 kA/cm(2) was obtained for a device with cavity length of 2 mm. Combined with the partial-high-reflection coating, the 1-mm-long DFB QCL achieved low power-consumption continuous wave (CW) operation up to 105 °C...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28420225/engineering-the-complex-valued-constitutive-parameters-of-metamaterials-for-perfect-absorption
#13
Pengwei Wang, Naibo Chen, Chaojun Tang, Jing Chen, Fanxin Liu, Saiqian Sheng, Bo Yan, Chenghua Sui
We theoretically studied how to directly engineer the constitutive parameters of metamaterials for perfect absorbers of electromagnetic waves. As an example, we numerically investigated the necessary refractive index n and extinction coefficient k and the relative permittivity ε and permeability μ of a metamaterial anti-reflection layer, which could cancel the reflection from a hydrogenated amorphous silicon (α-Si:H) thin film on a metal substrate, within the visible wavelength range from 300 to 800 nm...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28418634/protein-trapping-in-plasmonic-nanoslit-and-nanoledge-cavities-the-behavior-and-sensing
#14
Zheng Zeng, Xiaojun Shi, Taylor Mabe, Shaun Christie, Grant Gilmore, Adam W Smith, Jianjun Wei
A novel plasmonic nanoledge device was presented to explore the geometry-induced trapping of nanoscale biomolecules and examine a generation of surface plasmon resonance (SPR) for plasmonic sensing. To design an optimal plasmonic device, a semi-analytical model was implemented for a quantitative analysis of SPR under plane-wave illumination and a finite-difference time-domain (FDTD) simulation was used to study the optical transmission and refractive index (RI) sensitivity. In addition, total internal reflection fluorescence (TIRF) imaging was used to visualize the migration of fluorescently labeled bovine serum albumin (BSA) into the nanoslits; and fluorescence correlation spectroscopy (FCS) was further used to investigate the diffusion of BSA in the nanoslits...
April 18, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28417637/a-synergistic-enhancement-of-microwave-absorption-using-hybridized-polyaniline-helical-cnts-with-dual-chirality
#15
Xin Tian, Fanbin Meng, Fanchen Meng, Xiangnan Chen, Yifan Guo, Ying Wang, Wenjun Zhu, Zuowan Zhou
We designed a dual chirality hierarchical structure to achieve a synergistically enhanced effect in microwave absorption via the hybridization of nanomaterials. Herein, polyaniline (PANi) nanorods with tunable chirality are grown on helical carbon nanotubes (HCNTs), a typical nanoscale chiral structure, through in situ polymerization. The experimental results show that the hierarchical hybrids (PANi@HCNTs) exhibit distinctly dual chirality and display a significant enhancement in electromagnetic losses compared to either pure PANi or HCNTs...
April 18, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28415370/bubblelike-structures-generated-by-activation-of-internal-shape-modes-in-two-dimensional-sine-gordon-line-solitons
#16
Mónica A García-Ñustes, Juan F Marín, Jorge A González
Nonlinear waves that collide with localized defects exhibit complex behavior. Apart from reflection, transmission, and annihilation of an incident wave, a local inhomogeneity can activate internal modes of solitons, producing many impressive phenomena. In this work we investigate a two-dimensional sine-Gordon model perturbed by a family of localized forces. We observed the formation of bubblelike and droplike structures due to local internal shape mode instabilities. We describe the formation of such structures on the basis of a one-dimensional theory of activation of internal modes of sine-Gordon solitons...
March 2017: Physical Review. E
https://www.readbyqxmd.com/read/28415212/scaling-laws-of-reflection-coefficients-of-quantum-waves-at-a-cantor-like-potential
#17
Hidetsugu Sakaguchi, Taichi Ogawana
We reconsider a one-dimensional scattering problem in the Schrödinger equation with a Cantor-like potential. The reflection coefficient obeys a scaling law for sufficiently large wave number k. The scaling law is expressed with a universal function characterized by a multifractal.
March 2017: Physical Review. E
https://www.readbyqxmd.com/read/28412277/the-association-of-endothelial-function-and-tone-by-digital-arterial-tonometry-with-mri-left-ventricular-mass-in-african-americans-the-jackson-heart-study
#18
Avnish Tripathi, Emelia J Benjamin, Solomon K Musani, Naomi M Hamburg, Connie W Tsao, Arti Saraswat, Ramachandran S Vasan, Gary F Mitchell, Ervin R Fox
Peripheral vascular endothelial dysfunction assessed by digital peripheral arterial tonometry (PAT) has been associated with risk for adverse cardiovascular events. We examined the relations of peripheral microvascular dysfunction and left ventricular mass in a community-based cohort of African Americans. We examined participants of the Jackson Heart Study who had PAT and cardiac magnetic resonance imaging evaluations between 2007 and 2013. Consistent with pertinent literature, left ventricular mass index (LVMI) was adjusted for body size by indexing to height(2...
March 27, 2017: Journal of the American Society of Hypertension: JASH
https://www.readbyqxmd.com/read/28411335/development-of-a-puff-and-suction-type-pressure-stimulator-for-human-tactile-studies
#19
Hyung-Sik Kim, Mi-Hyun Choi, Soon-Cheol Chung
In this study, we developed a tactile stimulator capable of administering either puff- or suction-type stimuli. The system is composed of three parts: a control unit, an air-handling unit, and a stimulation unit. The control unit controls the type, intensity, and time of stimulation. The air-handling unit delivers the stimulation power quantitatively to the stimulation unit, as commanded by the control unit. The stimulation unit stably administers either type of pressure to the skin, without any change of the tactor...
April 14, 2017: Behavior Research Methods
https://www.readbyqxmd.com/read/28409948/observation-of-quantum-limited-spin-transport-in-strongly-interacting-two-dimensional-fermi-gases
#20
C Luciuk, S Smale, F Böttcher, H Sharum, B A Olsen, S Trotzky, T Enss, J H Thywissen
We measure the transport properties of two-dimensional ultracold Fermi gases during transverse demagnetization in a magnetic field gradient. Using a phase-coherent spin-echo sequence, we are able to distinguish bare spin diffusion from the Leggett-Rice effect, in which demagnetization is slowed by the precession of a spin current around the local magnetization. When the two-dimensional scattering length is tuned to be comparable to the inverse Fermi wave vector k_{F}^{-1}, we find that the bare transverse spin diffusivity reaches a minimum of 1...
March 31, 2017: Physical Review Letters
keyword
keyword
71051
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"