Academic literature on the topic 'Anomalies de rayleigh'
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Journal articles on the topic "Anomalies de rayleigh"
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Gao, Hongtao, Wei Yan, Song Hu, and Yudong Zhang. "Eliminating the Rayleigh anomalies in metal grating." Optics Communications 405 (December 2017): 8–11. http://dx.doi.org/10.1016/j.optcom.2017.07.062.
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van der Lee, S. "Observations and origin of Rayleigh-wave amplitude anomalies." Geophysical Journal International 135, no. 2 (November 1998): 691–99. http://dx.doi.org/10.1046/j.1365-246x.1998.00678.x.
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Savoia, Silvio, Armando Ricciardi, Alessio Crescitelli, Carmine Granata, Emanuela Esposito, Vincenzo Galdi, and Andrea Cusano. "Surface sensitivity of Rayleigh anomalies in metallic nanogratings." Optics Express 21, no. 20 (September 26, 2013): 23531. http://dx.doi.org/10.1364/oe.21.023531.
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Hara, Tatsuhiko, and Robert J. Geller. "Anomalously large near-field Rayleight waves excited by the 1992 Landers, California, earthquake." Bulletin of the Seismological Society of America 84, no. 3 (June 1, 1994): 751–60. http://dx.doi.org/10.1785/bssa0840030751.
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Abstract The epicenter of the Landers, California, earthquake (28 June 1992; MW = 7.3) was located near the TERRAscope network of broadband seismic stations. The direct Rayleigh wave arrivals, R1, were clipped, and the first two later arrivals, R2 and R3, were contaminated by the waves from a large aftershock, but, as reported by Kanamori et al. (1992a), the amplitudes of R4 and later great circle Rayleigh wave arrivals (fundamental mode spheroidal free oscillations) are about 10 times larger than predicted by synthetic seismograms for a spherically symmetric earth model. We show that, for the moment tensor of the Landers event (predominantly vertical strike slip), the amplitudes of synthetics at the TERRAscope stations for a laterally heterogeneous, rotating, elliptical model are about 10 times greater than those for a spherically symmetric model. Because the anomaly ratio is sensitive to both the source model and the three-dimensional (3D) earth model, we do not attempt to reproduce the exact anomaly ratios recorded by the various stations. To explain the existence of near-field amplitude anomalies in general, we use the first-order Born approximation to find the perturbation to the synthetic seismogram resulting from lateral heterogeneity, ellipticity, and the earth's rotation. In a coordinate system with the source on the z axis a point-source strike-slip earthquake on a vertical fault plane in a spherically symmetric medium excites Rayleigh waves with azimuthal order ±2 only; these waves have a near-field vertical displacement of zero at the source; the displacement increases with the square of epicentral distance for any given azimuth. Coupling as a result of asphericity allows such a source to excite Rayleigh waves with azimuthal order zero, whose near-field amplitude is independent of epicentral distance, thereby generating large near-field amplitude anomalies. We conduct numerical experiments to study the influence of various parameters on near-field amplitude anomalies.
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Mo, Ruping. "On Adding Thermodynamic Damping Mechanisms to Refine Two Classical Models of Katabatic Winds." Journal of the Atmospheric Sciences 70, no. 7 (July 1, 2013): 2325–34. http://dx.doi.org/10.1175/jas-d-12-0256.1.
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Abstract The Prandtl and layer-averaged models of katabatic winds contain some nonphysical singularities in the analytical solutions, which give unbounded steady flow anomalies at zero slope angles or adiabatic lapse rates. This study presents some simple refinements of these two classical models, in which the aforementioned singularities are removed when Newtonian cooling and Rayleigh friction are included in the system. It is pointed out that, in the limit of zero slope angles or adiabatic lapse rates, the along-slope buoyancy force and the adiabatic heating caused by air descending approach zero. Under such circumstances, a bounded steady solution for the katabatic winds is impossible unless some damping mechanisms are included to retard the anomalies induced by the radiative cooling effect in the boundary layer. Newtonian cooling and Rayleigh friction are the two simplest thermodynamic damping mechanisms that can be included to balance the effects of eddy viscosity and eddy thermal conductivity in the katabatic-flow model. Physically speaking, the Newtonian cooling term represents a small partition of the radiative effect and the Rayleigh friction term represents an approximation of the bottom drag effect in a turbulent boundary layer.
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Schreier, Frank, and Olof Bryngdahl. "Confined wave packets in the domain of Rayleigh–Wood anomalies." Journal of the Optical Society of America A 17, no. 1 (January 1, 2000): 68. http://dx.doi.org/10.1364/josaa.17.000068.
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Kolkowski, Radoslaw, and A. Femius Koenderink. "Gain-induced scattering anomalies of diffractive metasurfaces." Nanophotonics 9, no. 14 (July 26, 2020): 4273–85. http://dx.doi.org/10.1515/nanoph-2020-0253.
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AbstractPhotonic nanostructures with gain and loss have long been of interest in the context of diverse scattering anomalies and light-shaping phenomena. Here, we investigate the scattering coefficients of simple gain-doped diffractive metasurfaces, revealing pairs of scattering anomalies surrounded by phase vortices in frequency–momentum space. These result from an interplay between resonant gain, radiative loss, and interference effects in the vicinity of Rayleigh anomalies. We find similar vortices and singular points of giant amplification in angle-resolved reflectivity spectra of prism-coupled gain slabs. Our findings could be of interest for gain-induced wavefront shaping by all-dielectric metasurfaces, possibly employing gain coefficients as low as ∼50 cm−1.
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Cui, Yan, and Yanfei Wang. "Velocity modeling based on Rayleigh wave dispersion curve and sparse optimization inversion." Inverse Problems & Imaging 15, no. 5 (2021): 1121. http://dx.doi.org/10.3934/ipi.2021031.
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<p style='text-indent:20px;'>This paper studies the S wave velocity modeling based on the Rayleigh wave dispersion curve inversion. We first discuss the forward simulation, and present a fast root-finding method with cubic-order of convergence speed to obtain the Rayleigh wave dispersion curve. With the Rayleigh wave dispersion curve as the observation data, and considering the prior geological anomalies structural information, we establish a sparse constraint regularization model, and propose an iterative solution method to solve for the S wave velocity. Experimental tests are performed both on the theoretical models and on the field data. It indicates from the experimental results that our new inversion scheme possesses the characteristics of easy calculation, high computational efficiency and high precision for model characterization.</p>
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Darweesh, Ahmad, Stephen Bauman, Desalegn Debu, and Joseph Herzog. "The Role of Rayleigh-Wood Anomalies and Surface Plasmons in Optical Enhancement for Nano-Gratings." Nanomaterials 8, no. 10 (October 9, 2018): 809. http://dx.doi.org/10.3390/nano8100809.
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We propose and report on the design of a 1-D metallo-dielectric nano-grating on a GaAs substrate. We numerically study the impact of grating period, slit and wire widths, and irradiating angle of incidence on the optical response. The optimal wire width, w = 160 nm, was chosen based on previous results from investigations into the influence of wire width and nano-slit dimensions on optical and electrical enhancements in metal-semiconductor-metal photodetectors. In this present project, resonant absorption and reflection modes were observed while varying the wire and nano-slit widths to study the unique optical modes generated by Rayleigh-Wood anomalies and surface plasmon polaritons. We observed sharp and diffuse changes in optical response to these anomalies, which may potentially be useful in applications such as photo-sensing and photodetectors. Additionally, we found that varying the slit width produced sharper, more intense anomalies in the optical spectrum than varying the wire width.
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Bado, Mattia, Joan Casas, and António Barrias. "Performance of Rayleigh-Based Distributed Optical Fiber Sensors Bonded to Reinforcing Bars in Bending." Sensors 18, no. 9 (September 16, 2018): 3125. http://dx.doi.org/10.3390/s18093125.
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Distributed Optical Fiber Sensors (DOFSs), thanks to their multiple sensing points, are ideal tools for the detection of deformations and cracking in reinforced concrete (RC) structures, crucial as a means to ensure the safety of infrastructures. Yet, beyond a certain point of most DOFS-monitored experimental tests, researchers have come across unrealistic readings of strain which prevent the extraction of further reliable data. The present paper outlines the results obtained through an experimental test aimed at inducing such anomalies to isolate and identify the physical cause of their origin. The understanding of such a phenomenon would enable DOFS to become a truly performant strain sensing technique. The test consists of gradually bending seven steel reinforcement bars with a bonded DOFS under different conditions such as different load types, bonding adhesives, bar sections and more. The results show the bonding adhesives having an influence on the DOFS performance but not on the rise of anomalies while the reasons triggering the latter are narrowed down from six to two, reaching a strain threshold and a change in structure’s deformative behavior. Further planned research will allow identification of the cause behind the rise of strain-reading anomalies.
Dissertations / Theses on the topic "Anomalies de rayleigh"
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Hamdad, Sarah. "Synthèse et étude de réseaux de nanoparticules métalliques pour l'exaltation de l'électroluminescence des OLEDs via l'effet plasmonique." Thesis, Paris 13, 2021. http://www.theses.fr/2021PA131056.
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Dans ce travail de thèse, nous nous sommes intéressés à l’étude de l’amélioration des propriétés optiques et électriques des OLED en utilisant des réseaux de nanoparticules d’Ag. En particulier, nous nous sommes focalisés sur l’étude des résonances de réseau de surface (SLR) afin de comprendre l’origine des mécanismes d’interactions dans ces réseaux. Nous avons aussi étudié l’influence de ces modes sur les caractéristiques d’émission d’une couche organique d’abord en pompage optique et ensuite en pompage électrique. Pour cela, nous avons mis en place au sein du laboratoire LPL plusieurs bancs optiques et développé des calculs afin d’interpréter les résultats obtenus. Ces résultats confirment le rôle crucial des anomalies de Rayleigh dans l’interaction entre les NPs et les émetteurs organiques. En particulier, ils révèlent leur importance pour l’apparition d’une directivité de l’émission. Dans le cas des μOLED, les études réalisées montrent que la présence de réseaux de courtes périodes améliore le processus électrique d’injection des trous dans le dispositif. De plus, on montre également qu’il est possible d’exalter le rendement de la μOLED par l’insertion d’un réseau de longue périodicité. Toutefois, on souligne que l’existence de modes SLR et les effets de directivité de l’émission dans ces dispositifs nécessitent des études plus approfondies. Les résultats obtenus dans le cadre de cette thèse constituent un pas important vers une profonde compréhension des interactions entre les NPs métalliques et les émetteurs organiques et pourraient ouvrir la voie vers l’étude d’OLED superradiantes qui constituerait une étape intermédiaire pour aller vers la diode laser organiqueIn this thesis work, we were interested in studying the improvement of the optical and electrical properties of OLEDs using square arrays of Ag nanoparticles. In particular, we focused on the study of surface lattice resonance (SLR) modes in order to understand the interaction mechanisms between the NPs in a grating. We have also studied the influence of these modes on the emission characteristics of an organic layer first under optical pumping and then under electrical pumping. For this, we have set up within the LPL laboratory several optical experiments and developed several numerical calculations in order to interpret the obtained results. These latter confirm the crucial role of Rayleigh anomalies in the appearance of directional emission. In the case of OLEDs, the studies carried out show that the presence of short period metallic structures can help to improve the electrical injection process of holes into the organic device. Besides, we show that the insertion of a longue period grating can improve the efficiency of the OLED. However, the existence of collective SLR modes is not guaranteed in this type of configuration and the emission directivity effects require further studies. The results obtained within the framework of this thesis work constitute an important step towards a deep understanding of the interactions between the grating of metallic NPs and the organic emitters and could open the way towards the study and the realization of superriadiant OLEDs, which would constitute an intermediate step to go to the organic laser diode
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Bersan, Silvia. "Piping detection by Distributed Temperature Sensing: Understanding the development of thermal anomalies." Doctoral thesis, Università degli studi di Padova, 2015. http://hdl.handle.net/11577/3424217.
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Internal erosion is the cause of a significant percentage of damages involving water-retaining structures all over the world. In most cases, however, early detection of the phenomenon allows avoiding dramatic accidents. Developing monitoring techniques capable of detecting ongoing internal erosion with sufficient advance represents therefore a significant step towards a higher level of flood safety.
Temperature measurements performed in embankment dams have been proven to be effective in identifying leakages consequent to internal erosion. This work investigates the effectiveness of distributed fibre-optic temperature sensing for the early detection of internal erosion in river and sea dikes. The attention is focused on dikes prone to backward erosion piping, a mechanism that affects the foundation layer of structures resting on sandy soils.
The measurements performed in a large-scale piping test are presented and discussed. The test enabled the recognition of the main factors that influence the onset of thermal anomalies in regions affected by piping.
Subsequently, the effect of the above-mentioned factors was quantitatively studied with the aid of finite element modelling and dimensional analysis. It was discovered that early detection of piping cannot completely rely on the propagation of a thermal front (hot or cold depending on the season) that moves from the waterside to the landside with different speed in intact and eroded regions. Indeed, depending on the permeability and thickness of the sandy layer and on the size of the embankment, the duration of the flood event might not be sufficient for the front to reach a pipe not yet fully developed. However, another mechanism is exploitable for detection: the effect of the flow velocity on the natural vertical temperature gradient. Since this gradient decreases with depth, the effectiveness of this mechanism depends on the depth at which piping occurs.
The thesis also contains some tips for an effective numerical modelling of the advection-diffusion equation in permeable soils, both intact and affected by piping.
Finally, the thesis describes a small-scale setup that was developed to investigate the temperature distribution in the surroundings of a pipe. The model incorporates a distributed fibre-optic sensor with a sub-centimetre spatial resolution. Such resolution was achieved adopting a novel sensing technology, in which the spectral shift of the Rayleigh backscatter is measured using optical frequency-domain reflectometry. Preliminary results show how the cross-sensitivity of the sensor to temperature and strain influenced the measurements and how this was partially overcome.L'erosione interna è causa di una percentuale significativa di danni riguardanti le opere di ritenuta idraulica. Nella maggior parte dei casi tuttavia l'identificazione precoce del fenomeno permette di evitare incidenti drammatici. Sviluppare tecniche di monitoraggio in grado di individuare l'erosione interna in atto con sufficiente anticipo rappresenta pertanto un passo significativo verso una maggiore sicurezza idraulica. Questo lavoro indaga l'efficacia della misure distribuite di temperatura per l'individuazione precoce dell'erosione interna negli argini fluviali e costieri. La ricerca si concentra sugli argini suscettibili a sifonamento, intesa come l'erosione retrogressiva che interessa lo strato di fondazione di strutture poggianti su terreni sabbiosi. Vengono presentate e discusse le misure realizzate in un esperimento di sifonamento a grande scala. Il test ha permesso l'identificazione dei principali fattori che influenzano l'insorgenza delle anomalie termiche nelle regioni affette da sifonamento. Successivamente, l'effetto dei suddetti fattori è stato studiato quantitativamente con l'ausilio della modellazione agli elementi finiti e dell'analisi dimensionale. E’ emerso che l'individuazione precoce del sifonamento si non può basare esclusivamente sulla propagazione di un fronte termico (caldo o freddo a seconda della stagione) che si muove dal fiume verso campagna con velocità differente nelle zone integre ed erose. Infatti, in funzione della permeabilità e spessore dello strato sabbioso e della dimensione del rilevato, la durata della piena può non essere sufficiente affinché il fronte raggiunga un sifone non ancora pienamente sviluppato. Tuttavia si può sfruttare un meccanismo alternativo: l'effetto della velocità del flusso idraulico sul gradiente verticale naturale. Poiché tale gradiente diminuisce con la temperatura, l'efficacia di questo meccanismo dipende dalla profondità a cui il sifonamento si manifesta. La tesi contiene anche alcuni consigli per una modellazione numerica efficiente del problema di avvezione-diffusione in terreni permeabili, sia integri che affetti da sifonamento. Infine la tesi descrive un apparato sperimentale sviluppato per studiare in piccola scala la distribuzione di temperatura nei dintorni di un sifone. Il modello incorpora un sensore distribuito in fibra ottica con risoluzione spaziale sub-centimetrica. Tale risoluzione è stata ottenuta adottando una tecnica di misura innovativa basata sull'analisi della componente di Rayleigh nel dominio delle frequenze. I risultati preliminari mostrano l'influenza sulle misure della contemporanea sensibilità del sensore a temperatura e deformazione e come questo problema è stato parzialmente risolto.
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Gongora, Renan. "Theoretical Tailoring of Perforated Thin Silver Films for Surface Plasmon Resonance Affinity." Honors in the Major Thesis, University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/1543.
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Metallic films, in conjunction with biochemical-targeted probes, are expected to provide early diagnosis, targeted therapy and non-invasive monitoring for epidemiology applications [1-4]. The resonance wavelength peaks, both plasmonic and Wood-Rayleigh Anomalies (WRAs), in the scattering spectra are affected by the metallic architecture. As of today, much research has been devoted to extinction efficiency in the plasmonic region. However, Wood Rayleigh Anomalies (WRAs) typically occur at wavelengths associated with the periodic distance of the structures. A significant number of papers have already focused on the plasmonic region of the visible spectrum, but a less explored area of research was presented here; the desired resonance wavelength region was 400-500nm, corresponding to the WRA for the silver film with perforated hole with a periodic distance of 400nm. Simulations obtained from the discrete dipole approximation (DDA) method, show sharp spectral bands (either high or low scattering efficiencies) in both wavelength regions of the visible spectrum simulated from Ag film with cylindrical hole arrays. In addition, surprising results were obtained in the parallel scattering spectra, where the electric field is contained in the XY plane, when the angle between the metallic surface and the incident light was adjusted to 14 degrees; a bathochromic shift was observed for the WRA peak suggesting a hybrid resonance mode. Metallic films have the
potential to be used in instrumental techniques for use as sensors, i.e. surface plasmon resonance affinity biosensors, but are not limited to such instrumental techniques. Although the research here was aimed towards affinity biosensors, other sensory designs can benefit from the optimized Ag film motifs. The intent of the study was to elucidate metal film motifs, when incorporated into instrumental analysis, allowing the quantification of genetic material in the visible region. Any research group that routinely benefits from quantification of various analytes in solution matrices will also benefit from this study, as there are a bewildering number of instrumental sensory methods and setups available.B.S.
Bachelors
Sciences
Chemistry
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Ahmidayi, Najat. "Déformations de systèmes plasmoniques : application aux nanocapteurs de déformations." Electronic Thesis or Diss., Université de Lille (2022-....), 2024. http://www.theses.fr/2024ULILN022.
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Basée sur l'exploitation des propriétés optiques des nanoparticules métalliques en combinaison avec des matériaux flexibles, la plasmomécanique a émergé récemment comme un sous-domaine de la nano-optomécanique. Les systèmes plasmomécaniques permettant de mesurer les contraintes mécaniques appliquées aux substrats flexibles à partir de la réponse plasmonique des nanostructures ont attiré beaucoup d'attention dans le domaine de la recherche scientifique en raison de leurs potentielles applications, notamment dans les détecteurs de contraintes.La compréhension de la réponse mécanique microscopique à une déformation macroscopique est un fondement de la plasmomécanique, essentiel pour comprendre la réponse optique des nanostructures et son évolution. Le premier objectif de cette thèse est de comprendre, par des outils de simulation numérique, les réponses mécanique et plasmonique, et plus précisément comment les distances interparticules évoluent à l'échelle nanométrique lorsqu'une contrainte mécanique macroscopique est imposée et influencent la réponse plasmonique du système. Cela sera étudié à travers des systèmes plasmomécaniques simples composés de nanodimères d'or déposés sur une membrane de PDMS.Un autre défi de ce domaine est la conception de systèmes plasmomécaniques ayant une grande sensibilité aux déformations mécaniques. Cela peut être réalisé par des systèmes plasmoniques supportant des modes de résonance avec des pertes minimales (petite largeur à mi-hauteur). Ainsi, le deuxième objectif de cette thèse est de réaliser des systèmes plasmomécaniques supportant des résonances telles que la résonance de Fano dans un système de bâtonnet-disque et la résonance de surface de réseau dans un réseau 2D d'anneaux d'or, deux résonances connues pour leur profil de résonance fin et étroitBased on the exploitation of the optical properties of metallic nanoparticles in combination with flexible materials, plasmonomechanics has recently emerged as a subfield of nano-optomechanics. Plasmonomechanical systems, which enable the measurement of mechanical strains applied to flexible substrates through the plasmonic response of nanostructures, have attracted much attention in the scientific research community due to their potential applications, notably in strain detectors.Understanding the microscopic mechanical response to macroscopic deformation is a foundation of plasmonomechanics, essential for comprehending the optical response of nanostructures and its evolution. The first objective of this thesis is to understand, through numerical simulation tools, the mechanical and plasmonic responses, and more precisely, how interparticle distances evolve at the nanometric scale when macroscopic mechanical strain is imposed and influence the plasmonic response of the system. This will be studied through simple plasmonomechanical systems composed of gold nanodimers deposited on a PDMS membrane.Another challenge in this field is the design of plasmonomechanical systems with high sensitivity to mechanical deformations. This can be achieved through plasmonic systems supporting resonance modes with minimal losses (narrow linewidth). Thus, the second objective of this thesis is to realize plasmonomechanical systems supporting resonances such as the Fano resonance in a rod-disk system and the surface lattice resonance in a 2D array of gold nanorings, both known for their sharp and narrow resonance profiles
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Xu, Chao Qiang. "Localization of Near-Surface Anomalies Using Seismic Rayleigh Waves." 2010. http://hdl.handle.net/10222/12812.
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The presence of subsurface anomalies, such as cavities, faults, unknown tunnels, etc., either natural or man-made, can cause public safety hazards. The detection of these features requires the development of new methods. Seismic Rayleigh surface wave imaging is a relatively new non-destructive testing technique (NDT) which generates subsurface images without drilling boreholes into the ground, and in recent years has been widely used for soil characterization in geotechnical investigations. In the last decade, some researchers have applied the technique to near-surface imaging and showed the possibility and potential for engineering applications.
This research presents the development of a technique to process seismic Rayleigh waves to detect and image subsurface anomalies. This study conducted investigations of Rayleigh wave behaviors and developed a new strategy for Rayleigh wave isolation from raw field data. The strategy applies wavelet transforms, instead of the conventional spectral analysis of surface waves (SASW) method, or popular multichannel analysis of surface waves (MASW) techniques, to pair-channel analysis of the isolated Rayleigh wave data for dispersion calculation. Finally, a simple steady inversion technique was applied to yield shear velocity as a function of both depth and distance, and shear velocity field images (SVF), for near surface section display.
This research consists of development, computer programming, field tests, data processing and interpretation. Three sites in different scenarios were used for seismic investigations: old mining tunnels in medium dipping coal seams in Stellarton coalfield, mining cavities in steeply dipping gold-bearing veins in West Waverley Gold District and an anomaly in nearly horizontal strata in Liverpool. All these sites are in the province of Nova Scotia, Canada. The results from seismic surface wave technique introduced in this research can be evaluated by field observations, documents and borehole logs. The satisfactory interpretations and success of this investigation shows that this technique is suitable for engineering application for subsurface investigations.
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Wen-YuChen and 陳文瑜. "Theoretical Studies on Localized Surface Plasmon Resonances of Nanoparticle Arrays—Standing-Wave Modes, Optical Phase Characteristics, and Rayleigh Anomalies." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/hsh5ch.
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博士國立成功大學
光電科學與工程學系
102
This thesis presents theoretical studies on the optical characteristics of localized surface plasmon resonances (LSPRs) in spectra of periodic nanoparticle arrays. Three subjects have been discussed: the excitations of standing-wave modes in split-ring resonators (SRRs), the optical phase characteristics of nanodot arrays, and the impacts of Rayleigh anomalies on LSPR spectra. We investigate the excitations of standing-wave modes of SRRs with different incident angles and polarizations. Two changes at oblique incidence with respect to normal incidence are investigated—the excitations of dark modes with linear polarizations and the deviation of spectra of right- and left-handed circular polarizations. We find that the parallelism between the incident electric field and the induced plasmon current is the key factor affecting the excitation. We propose the use of a P-factor to characterize the ability of incident fields to excite standing-wave modes. We analytically model the intensity and the phase spectra of silver nanodots with temporal-coupled mode theory (TCMT). The focus is on phase characteristics that are a π jump for reflection and a zigzag transition for transmission. We derive the equation of phase slope at the zigzag transition of transmission. The equation shows that the Ohmic absorption decreases the phase slope. We further investigate plasmonic phase retardation in anisotropic nanodot arrays. We discovered that the bandwidth of phase retardation could be much narrower than the LSPR bandwidth if the long and the short side lengths of the nanodots are very close. We propose the application of plasmonic phase retardation in refractive index sensing. In this sensing algorithm, the sensor figure-of-merit is greatly enhanced. We have developed a theoretical model based on TCMT for LSPRs coupled with Rayleigh anomalies (TCMT-RA). TCMT-RA is used for analyzing the spectra of nanodot arrays with various periods and dot sizes. We calculate the reciprocal of external quality factor, which means the percentage of LSPR energy radiating to far field per oscillation cycle, and find that the value is universally proportional to the nanodot coverage. The Rayleigh anomalies have four effects on the LSPR spectra, namely, redshift of LSPR, asymmetric line shape, bandwidth reduction, and increased phase slope. The results show that the decrease in the size-to-period ratio of nanodot array enhances the effects of Rayleigh anomalies.
Book chapters on the topic "Anomalies de rayleigh"
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Ricciardi, A., S. Savoia, A. Crescitelli, V. Galdi, A. Cusano, and E. Esposito. "Sensitivity of Wood-Rayleigh Anomalies in Metallic Nanogratings." In Lecture Notes in Electrical Engineering, 241–44. Cham: Springer International Publishing, 2013. http://dx.doi.org/10.1007/978-3-319-00684-0_46.
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Baraldi, C., E. Casnati, G. Di Domenico, and A. Tartari. "Implementation of the Anomalous Dispersion of Rayleigh Scattered Photons in EGS4 Code." In Advanced Monte Carlo for Radiation Physics, Particle Transport Simulation and Applications, 75–80. Berlin, Heidelberg: Springer Berlin Heidelberg, 2001. http://dx.doi.org/10.1007/978-3-642-18211-2_13.
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Cao, Kang, Zhi-Ming Yang, Zeng-qian Hou, Noel C. White, and Chao Yu. "Contrasting Porphyry Cu Fertilities in the Yidun Arc, Eastern Tibet: Insights from Zircon and Apatite Compositions and Implications for Exploration." In Tectonomagmatic Influences on Metallogeny and Hydrothermal Ore Deposits: A Tribute to Jeremy P. Richards (Volume II), 231–55. Society of Economic Geologists, 2021. http://dx.doi.org/10.5382/sp.24.13.
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Abstract The Yidun arc, part of the Sanjiang Paleo-Tethyan orogenic belt in eastern Tibet, hosts several porphyry Cu deposits in its southern section, whereas abundant contemporaneous but barren granitoid intrusions occur in the northern section. Here we present an integrated, temporally constrained dataset of zircon and apatite compositions together with whole-rock geochemical results for both the fertile and barren suites in the Yidun arc. We investigate the probable factors leading to such contrasting porphyry Cu fertilities and also assess the application of geochemical and mineral proxies for porphyry Cu exploration. Both the fertile and barren suites in the Yidun arc share similar petrographic and geochemical characteristics typical of arc magmas. However, the two suites have distinct differences in certain trace elements and element ratios (e.g., Sr, Y, Sr/Y, V/Sc, Eu anomaly). The fertile suites have adakite-like character, with high Sr/Y, La/Yb, and V/Sc ratios, and show no or minimal negative Eu anomalies, indicating early dominant amphibole with limited plagioclase fractionation. By contrast, the barren suites have low Sr/Y, La/Yb, and V/Sc ratios, and display minimal to significant negative Eu anomalies. These barren suites probably formed by crystal fractionation dominated by plagioclase, with limited amphibole crystallizing from the same parental magma. Zircon geochemical data for both suites combined with Rayleigh fractionation modeling show that zircon compositions (e.g., Hf, Ti, [Yb/Dy]N, Eu/Eu*, Ce/Nd) are affected by the compositions, water content, and redox state of the parental magma, as well as by prior or concurrent crystallization of minerals (e.g., plagioclase, amphibole, apatite, titanite). For the fertile suites, the high zircon Eu/Eu* (0.43–0.91), ΔFMQ (0.8–2.4; where ΔFMQ is the log fO2 difference between the sample value and the fayalite-magnetite-quartz mineral buffer), the presence of the assemblage amphibole + titanite + quartz + magnetite, and high whole-rock Fe2O3/FeO, Sr/Y and V/Sc ratios, collectively indicate that associated magmas were hydrous and oxidized. For the barren suites, the common presence of the assemblage amphibole + ilmenite, low zircon Eu/Eu* (0.01–0.34) and ΔFMQ (–3.3 to +0.5), and low whole-rock Fe2O3/FeO, Sr/Y, and V/Sc ratios, together indicate that the related magmas were hydrous but reduced. Magmatic apatites in the fertile suites have higher SO3 contents (0.07–0.79 wt %) than those in the barren suites (<0.04 wt % SO3). The estimated magmatic sulfur contents for the fertile suites are 35 to 160 ppm, whereas for the barren suites, their related magmas were sulfate poor. Compared to the hydrous, oxidized, and S-rich fertile suites in the southern Yidun arc, the reduced and sulfate-poor characteristics of the barren suites hinder the transport of adequate S and metals to form porphyry Cu deposits, even though they are hydrous; thus there is little potential for porphyry Cu deposits in the northern Yidun arc. Whole-rock Sr/Y (>20), V/Sc (>32.5–0.385 × wt % SiO2), Eu/Eu* (~1) and 10,000*(Eu/Eu*)/Y (>400) ratios, zircon Eu/Eu* (>0.4) and ΔFMQ (>1), and apatite SO3 contents (>0.1 wt %) can help to discriminate porphyry Cu intrusions from barren granitoids in the Yidun arc, indicating their usefulness as porphyry Cu fertility indicators. The zircon Ce anomaly (Ce4+/Ce3+, Ce/Ce*, Ce/Nd), however, overlaps between the oxidized fertile and reduced barren suites, hampering its use to estimate relative magmatic redox state and as a robust porphyry Cu fertility indicator. The combination of whole-rock analyses and zircon and apatite compositions helps focus porphyry Cu exploration on prospective areas, coupled with investigations of structural geology, geophysical surveys, and mapping of hydrothermal alteration.
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Bertlmann, Reinhold A., and Nicolai Friis. "Perturbative Methods in Quantum Mechanics." In Modern Quantum Theory, 269–318. Oxford University PressOxford, 2023. http://dx.doi.org/10.1093/oso/9780199683338.003.0010.
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Abstract In this chapter we review time-independent and time-dependent perturbation theory in quantum mechanics. We begin with Rayleigh-Schrödinger perturbation theory for small corrections to the Hamiltonian for non-degenerate and degenerate spectra, which leads us to a discussion of avoided crossings. We then apply these methods to calculate the fine-structure corrections for the energy levels of the hydrogen atom, including the relativistic correction to the kinetic energy, the spin-orbit correction, and the Darwin term. We then turn to the effect of weak constant magnetic fields: for the resulting Zeeman effect we distinguish between the anomalous Zeeman effect and the Paschen-Back effect. In the context of the corresponding Stark effect for electric fields we introduce the Wigner-Eckart theorem and calculate perturbations to first and second order. We then turn to time-independent problems and discuss the Born-von Neumann series for the propagator, time-ordered integrals, the interaction picture, before explaining Fermi’s golden rule.
Conference papers on the topic "Anomalies de rayleigh"
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Novikov, Mikhail, Artem Krylov, and Konstantin Roginskiy. "RECEIVER FUNCTIONS APPLICATION FOR STUDYING THE DEEP STRUCTURE OF THE LENA DELTA REGION." In 24th SGEM International Multidisciplinary Scientific GeoConference 24, 507–14. STEF92 Technology, 2024. https://doi.org/10.5593/sgem2024/1.1/s05.64.
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Receiver function analysis is a critical tool in seismology, used to study the deep structure of the crust and upper mantle. Information about the deep structure of the crust and seismicity is important initial data for developing a source model and seismic hazard assessment. The presence of sharp discontinuities beneath the monitoring station induces the generation of converted body waves, which propagate at slower velocities than those of the primary P-wave. Receiver function analysis utilizes the lag between the arrival times of converted waves to estimate the depths of interfaces. Furthermore, by using various inversion algorithms, including receiver function inversion and surface wave group velocity inversion, a shear wave velocity model under the station can be inferred. This study seeks to examine the depth-velocity structure of the Lena Delta by analyzing receiver functions and surface-wave data. Receiver function analysis was performed using waveforms from the TIXI station, a component of the Yakutsk Regional Seismic Network of the Russian Federation. For the analysis, 245 large earthquakes (Ml > 7) occurring between 2000 and 2024, and located at distances ranging from 20� to 100� from the station, were initially selected. The iterative deconvolution was then used to obtain radial and transverse receiver functions. Three different inversion algorithms were used to attain the velocity model: receiver function inversion (rftn96), Rayleigh group wave velocity inversion (surf96), and joint inversion (joint96). A wide peak lasting from 3 to 5 seconds after the initial P-wave arrival and a sharp peak at 7.5 seconds were observed on the radial receiver function. The presence of two distinct peaks complicates the application of conventional H-k stacking analysis, which assumes a single discontinuity. Rayleigh wave group velocity inversion only showed one sharp increase in shear wave velocity at 15 km, while both receiver function inversion and joint inversion showed step-like increases at 15, 30, and 40 km, which indicates the presence of layer boundaries at these depths. The obtained values are consistent with existing data on the region, including deep seismic sounding profiles and crustal models. Previous research, along with the findings of this study, indicates that 15 km is most likely the boundary between the upper and the lower crust, 30 km is a transition to the anomalous mantle, and 40 km is the Moho boundary.
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Yu, Aisheng, Wei Li, Yuelin Wang, and Tie Li. "Mid-infrared bandwidth reduction of LSPR by Rayleigh Anomalies." In 2017 IEEE 12th International Conference on Nano/Micro-Engineered and Molecular Systems (NEMS). IEEE, 2017. http://dx.doi.org/10.1109/nems.2017.8016994.
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Tamir, T. "Wood's anomalies in Gaussian beams diffracted by gratings." In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1989. http://dx.doi.org/10.1364/oam.1989.tubb1.
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Wood's anomalies in light reflected by gratings refer to unexpectedly strong variations in the intensity of diffracted orders within narrow spectral bands. Two principal varieties of such behavior have been identified: (a) Rayleigh anomalies, which occur when one of the higher diffracted order is changing from propagating to evanescent, and (b) resonant anomalies, which appear if the incident field is phase matched to the harmonic of a leaky wave guided by the grating. These phenomena have been investigated theoretically for incident plane waves, but the behavior of realistically bounded beams in anomalous conditions has been considered only for very restricted situations. We therefore examine Gaussian beams incident on a simple canonic model of reflection gratings and show that the diffracted beams may exhibit strong spatial (lateral, longitudinal, and angular) shifts as well as a change in their effective cross section. Our results thus provide a unified phenomenological explanation of Wood's anomalies and beam modification phenomena in wave scattering by periodic structures.
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Sharma, Swastika, Stephen Butt, and Ralph Phillip Bording. "Rayleigh Wave Modeling in Laterally Inhomogeneous Media with Subsurface Anomalies." In Symposium on the Application of Geophysics to Engineering and Environmental Problems 2009. Environment and Engineering Geophysical Society, 2009. http://dx.doi.org/10.4133/1.3176696.
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Belotelov, V. I., L. L. Doskolovich, V. A. Kotov, E. A. Bezus, D. A. Bykov, and A. K. Zvezdin. "Magneto-optical effects at the Rayleigh-Wood and plasmon anomalies." In The International Conference on Coherent and Nonlinear Optics, edited by Oleg A. Aktsipetrov, Vladimir M. Shalaev, Sergey V. Gaponenko, and Nikolay I. Zheludev. SPIE, 2007. http://dx.doi.org/10.1117/12.752363.
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Sharma, S., S. Butt, and P. Bording. "Rayleigh wave modeling in laterally inhomogeneous media with subsurface anomalies." In 22nd EEGS Symposium on the Application of Geophysics to Engineering and Environmental Problems. European Association of Geoscientists & Engineers, 2009. http://dx.doi.org/10.3997/2214-4609-pdb.157.sageep001.
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Ricciardi, Armando, Silvio Savoia, Alessio Crescitelli, Emanuela Esposito, Vincenzo Galdi, and Andrea Cusano. "Surface vs. bulk sensitivity of sensors based on Rayleigh anomalies in metallic nanogratings." In SPIE Optics + Optoelectronics, edited by Francesco Baldini, Jiri Homola, and Robert A. Lieberman. SPIE, 2013. http://dx.doi.org/10.1117/12.2017233.
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Petruskevicius, R., and Z. Kuprionis. "Wood’s Anomalies in Self-Diffraction." In The European Conference on Lasers and Electro-Optics. Washington, D.C.: Optica Publishing Group, 1996. http://dx.doi.org/10.1364/cleo_europe.1996.ctuk22.
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It is known that the Wood’s anomalies can be observed on "permanent” diffraction gratings under certain conditions [1,2]. These anomalies may occur both in TM and TE polarizations of incident light and can be of different types "Rayleigh”, "leaky-wave resonance” and "Bragg-angle” types of anomalies. Stimulated Wood’s anomalies [3] can develop on the surface illuminated by a single laser beam of sufficient intensity as spontaneous highly periodic surface ripples Conventionally, laser light self-diffraction on two-wave induced dynamic gratings in a thin nonlinear film is studied in the Raman-Nath approach not taking into consideration the possibility of any Wood’s anomalies [4]. We have shown that Wood’s anomalies can be observed not only on the “permanent” diffraction gratings but also on the two-wave induced dynamic gratings [5]. We consider the Wood’s anomalies of "leaky-wave resonance” type to be related to excitation of surface polaritons or guided waves in the thin slab by means of induced dynamic gratings. These anomalies occur when one or two counterpropagating off-Bragg self-diffraction orders skim along the illuminated thin slab at some angles of degenerate two incident wave mixing. These leaky-wave resonances give rise to enhancement of local field and all nonlinear processes on the surface. The self-diffraction of laser light at these resonances exhibits instabilities which were not considered previously. The goal of this report is to present results of study of these new phenomena which would be important for nonlinear optical probing of surfaces and multiwave mixing processes in thin films.
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Laamiri, Youness, Frederic Garet, Jean-Louis Coutaz, and Lindsay Botten. "Precise analysis of Wood-Rayleigh anomalies in the terahertz transmission spectrum of a metallic hole array." In 2010 35th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz 2010). IEEE, 2010. http://dx.doi.org/10.1109/icimw.2010.5612503.
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Natarov, Denis M., Olga V. Shapoval, Marian Marciniak, and Alexander I. Nosich. "Rayleigh anomalies in the E-polarized wave scattering by finite flat gratings of silver nanostrips or nanowires." In 2012 International Conference on Mathematical Methods in Electromagnetic Theory (MMET). IEEE, 2012. http://dx.doi.org/10.1109/mmet.2012.6331215.
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