Schematic Level Research Articles

Energy Transfer from Ce3+ to Tb3+ /Dy3+ /Mn2+ in Ca9 Ga(PO4 )7 Phosphors: Synthesis, Structure and Tunable Multicolor Luminescent Properties.

A series of Ca9 Ga(PO4 )7 :Ce3+ /Tb3+ /Dy3+ /Mn2+ phosphors with tunable color, in which Ce3+ acts as the sensitizer, was synthesized. Energy transfer (ET) from Ce3+ to Tb3+ /Dy3+ /Mn2+ was investigated in detail. Tb3+ /Dy3+ /Mn2+ single-doped Ca9 Ga(PO4 )7 can exhibit green, yellow, and red emission, respectively. Incorporating Ce3+ into a Tb3+ /Dy3+ /Mn2+ single-doped Ca9 Ga(PO4 )7 phosphor can remarkably promote the luminous efficiency of the Tb3+ /Dy3+ /Mn2+ ions. This enhancement originates from an efficient ET from Ce3+ to Tb3+ /Dy3+ /Mn2+ . The ET was validated by luminescence spectra, decay dynamics, and schematic energy levels. Moreover, the intensity ratio of red emission of Mn2+ to violet emission of Ce3+ was analyzed based on energy-transfer and lifetime measurements. In Ce3+ -Tb3+ , Ce3+ -Dy3+ , and Ce3+ -Mn2+ doped Ca9 Ga(PO4 )7 , the emitting color changed from violet to green, yellow, and red, respectively, which indicates the potential use of this new tunable phosphor in UV light-emitting diodes.

Constructions Waxing and Waning: A Brief History of the Zero-Secondary Predicate Construction

In the English Secondary Predicate Construction (SPC), a predicative relation between a noun phrase (NP) and a “secondary predicate” (XP) is established by a main verb ( He finds Verb her NP attractive XP). While the syntactic nature of this construction has received ample attention from a synchronic perspective, this study aims to shed light on the diachronic developments of the SPC. First, using data from the York-Toronto-Helsinki Corpus of Old English Prose (YCOE) and the Penn corpora, a classification is proposed of the verbs occurring in the SPC. Based on this semantic classification, the development of the SPC is then traced from Old English to Late Modern English in terms of frequency and productivity. It is argued that, while the various classes of SPC-taking verbs often show opposite developments, these lower-level incongruities are resolved at a higher schematic level, as the SPC as a whole underwent a process of internalization. These findings underscore the importance of lower-level developments in the diachronic behavior of schematic constructions and consequently contribute to the literature on constructional change.

A standard-blocker tolerant receiver front-end using noise-canceling LNA with passive N-path filter and variable pulse-width multi-phase clock generator

In this paper, input impedance characteristics of N-path filters is used to reject standard blockers at the input port of a receiver front-end. Due to using variable capacitors in the multiphase LO generator, the results of each performance parameter of the design shows a slight change in value at the whole of frequency range. The receiver NF is about 2.45 dB at 1 GHz switching frequency. The proposed receiver front-end is analyzed and is simulated at the schematic level using CMOS 90 nm technology with a 1.5 V supply voltage.

Erbium doped sodium magnesium boro-tellurite glass: Stability and Judd-Ofelt analysis

Understanding the influence of rare earth ions in improving the optical properties of glasses are important in order to extend in advanced application. The behavior of series of Er3+ (1.0–2.0 mol %) doped B2O3-TeO2-MgO-Na2O glasses synthesized by conventional melt-quenching technique are explored. X-ray diffraction (XRD) pattern confirms the amorphous nature of the prepared glass sample. The DTA data asserts that the addition of Er3+ increased the thermal stability from 142 to 207 °C. The UV–VIS–NIR spectra reveal ten absorption bands centered at 4G11/2, 2H9/2, 4F5/2,4F7/2, 2H11/2, 4S3/2,4F9/2, 4I9/2, 4I11/2 and 4I13/2 from ground state of 4I15/2. The Judd–Ofelt Ω2 parameter values gradually decreases with the increase of erbium ions concentration from 0.5 to 2 mol %. From the Judd–Ofelt parameters (Ωt), transition probabilities (A), branching ratios (βR) of various transitions and their radiative lifetimes (τrad) are calculated. The up-conversion emission spectra of Er3+ exhibit four peaks centered at 538 nm, 554 nm, 653 nm and 822 nm assigned to 2H11/2 → 4I15/2, 4S3/2 → 4I15/2,4F9/2 → 4I15/2 and 4I9/2 → 4I15/2 transitions respectively in all samples. The maximum enhancement is evidenced at 1.5 mol% of Er2O3 by a factor of 3.11, 1.88 and 2.80 times for 2H11/2 → 4I15/2, 4S3/2 → 4I15/2 and 4I9/2 → 4I15/2 transitions respectively. A schematic energy level diagram is proposed. The effective band width at half maximum (FWHM) (Δλeff), stimulated emission cross-section (δPE) and the product of δPE×FWHM for 4S3/2 transitions of the glasses have also been studied and reported.

Achieving Weak Light Response with Plasmonic Nanogold-Decorated Organic Phototransistors.

Weak light response of organic photodetectors has fascinating potentials in fields of modern science and technology. However, their photoresponsivity is hindered by poor photocarrier excitation and transport. Decorating active-layer surface with plasmonic nanometals is considered a viable strategy to address this issue. Here, we demonstrate a plasmonic nanogold decorated organic phototransistor achieving remarkable enhancement of photoresponsivity. Meanwhile, the photoresponsive range is broadened by 4 orders of magnitude. The proposed design is substantiated by a schematic energy level model combined with theoretical simulation analysis, enabling the development of the advanced optoelectronics.

CaMoO4:Dy3+,Eu3+ phosphors: microwave synthesis, characterization, tunable luminescence properties and energy transfer mechanism

A series of Dy3+/Eu3+ co-doped CaMoO4 phosphors were synthesized by a rapid microwave synthesis method. The samples were investigated using X-ray powder diffraction (XRD), scanning electron microscope (SEM), fourier transform infrared (FT-IR) spectra, diffused reflectance spectra, fluorescence spectrometer, and photoluminescence decay curves, respectively. The XRD results indicated that all the samples were pure tetragonal CaMoO4 structure. The as-synthesized samples exhibited cubic particles and some irregular polyhedron particles. The big cubic particles were assembled by many closely packed quasi-spherical grains. Under 301 nm excitation, the increase of Eu3+ content in CaMoO4:Dy3+,Eu3+ led to the enhancement of red emission (613 nm) of Eu3+ and the decrease of blue and yellow emissions of Dy3+, which was possibly due to the efficient energy transfer (ET) from level of Dy3+ to 5D0 level of Eu3+ through the phonon-aided non-radiative relaxation. The phosphors could generate different color light from yellow-green through yellow and orange-reddish and eventually to red by properly tuning the content of Eu3+ based on the ET process, which suggested that they might be potentially applied in the fields of lighting and display. Besides, the possible energy transfer mechanism and schematic energy level diagram were discussed in detail.

Synthesis method of digital-to-analog converter schematic models for integrated circuits

Subject of Research.Parasitic parameters, which appear on layout design stage of analog schematic model, cause negative effect on analog block performance. The presence of negative effect of parasitic parameters can be the reason for block inadequacy to its technical requirements. It leads to new design of schematic model. Since there is no automatic approach for generation of schematic models, which takes into account all types of parasitic parameters, time-consuming design efforts increase. The paper presents features of automated moving from analog behavioral models to schematic ones. It is shown that detailed analysis of different types of parasitic parameters should be performed on schematic level to eliminate them from layout. Method. A method of analog model synthesis for digital-to-analog converter (DAC) is proposed. The proposed method improves block performance by minimization of parasitic parameters and provides technology migration. Main Results. The method contains additional stages as compared to traditional design flow: generation of schematic models from behavioral models, analysis of different types of parasitic parameters and the stage of model refinement. For implementation of the generation stage the software was designed, which performs automated generation of schematic model from behavioral description. The method was used to design 12-bit DAC on 350 nm technology. Parasitic parameters were defined and eliminated to increase the block high-speed performance. Practical Relevance. The proposed method can be used for DAC design on any technology. The method allows decreasing the effect of parasitic parameters and reducing design effort. The method gives the possibility for generating several architecture variants at once.

A wideband receiver front-end using 1st and 3rd harmonics of the N-path filter response

Harmonic selectivity and inaccessibility to accurate low-power high frequency clock generator are two main imperfections in the tunable N-path filters. In this paper, conventional N-path filter and conventional harmonic rejection (HR) N-path architectures are analyzed, and related equations are derived and are verified by simulation results. Furthermore, a wideband tunable receiver front-end using HR N-path switching systems is proposed. Using third harmonic of filter response instead of fundamental harmonic, the required input clock frequency in the multi-phase clock generator is decreased by a factor of three. The receiver front-end benefits low and high frequency bands. At low frequency band (0.4–1.2 GHz) the first harmonic, and at high frequency band (1.2–3.3 GHz) the third harmonic of filter response are selected and are downconverted to the baseband frequency. The structure is designed and is simulated using CMOS-90 nm technology in schematic level. The total power consumption and $$S_{11}$$ are $$<27.14$$ mW and $$-13.5$$ dB, respectively. Furthermore, NF at low and high frequency bands are 2.56 and 3.53 dB, respectively.

Embodied frames and scenes

AbstractThis paper lays out the foundations of a frame-based account of gesture pragmatics through detailing how frames and metonymy interact not only in motivating gestural sign formation, but also in guiding crossmodal processes of pragmatic inferencing. It is argued that gestures recruiting frame structures tend to profile deeply embodied, routinized aspects ofscenes(in the Fillmorian sense of the term), that is, of the motivating context of frames. Two kinds of embodied frame structures situated at different levels of abstraction, schematicity, and entrechment are proposed: (A)Basic physical action and object framesunderstood as directly experientially grounded frames involving physical action and interaction with the material and social world; (B)Complex, highly abstract frame structuresthat are more detached from the motivating contexts of experience. It is further suggested that gestures exhibiting a comparably low degree of iconicity and/or indexicality are likely to assume pragmatic rather than referential functions. Finally, potential avenues for further research into the relation of scenes, frames, and (multimodal) constructions are outlined.

De cláusulas matrizes a construções parentéticas epistêmicas: uma abordagem construcional

Adotando pressupostos teóricos da Linguística Centrada no Uso, este artigo analisa, sob uma perspectiva construcional, construções parentéticas epistêmicas de base clausal verbal portuguesas, em especial aquelas instanciadas por (eu) acho que e (eu) acho, quanto a níveis de esquematicidade (TRAUGOTT; TROUSDALE, 2013).&#x0D; &#x0D; ---&#x0D; DOI: http://dx.doi.org/10.22409/cadletrasuff.2017n55a515

Luminescence Studies of Erbium Doped Sodium Magnesium Boro-Tellurite Glass

The optical behaviour of Er3+ (1.0 – 2.0 mol %) doped B2O3-TeO2- Na2O-MgO glasses synthesized by conventional melt-quenching technique was studied through luminescence measurements. The X-ray diffraction (XRD) pattern confirms the amorphous nature of the glasses without the existence of any sharp peak. The emission spectra at 378 nm excitation displayed three emission peaks corresponding to 2H11/2-4I15/2, 4S3/2-4I15/2 and4I9/2-4I15/2 transitions. Hence, a schematic energy level diagram was proposed. The luminescence properties of the prepared glasses was found to be strongly affected by varying the concentration of Er3+ ions.

Luminescence Emission in Borotellurite Glass Containing Manganese Nanoparticles Doped Eu&lt;sup&gt;3+&lt;/sup&gt; Ions

A series of europium doped magnesium borotellurite glasses embedded with manganese nanoparticles (Mn3O4 NPs) of composition (59-x)TeO2-30B2O3-10MgO-x1Eu2O3-1Mn3O4 with 0.5 ≤ x ≤ 1.5 mol % are prepared using melt quenching technique. The existence of broad hump in X-ray diffraction (XRD) pattern verifies the amorphous nature of glasses. The presence of Mn3O4 NPs with average diameter of ~11 nm and (1 0 3) lattice plane having 0.276 nm spacing in the glass matrix is confirmed by high resolution transmission electron microscope (HRTEM) image. The glass samples are excited under 390 nm excitation wavelength and the emission spectra are found to consist of four emission peaks centred at 587 nm, 610 nm, 651 nm and 700 nm assigned to the transition from 5D0 →7FJ (J = 1, 2, 3, 4) states. The schematic energy level diagram is proposed. All results will be discussed with respect to the composition of Eu3+ ion.

Influence of TiO2 and Si on the exciton–phonon interaction in PbI2 and CdS semiconductors evidenced by Raman spectroscopy

The exciton–phonon interaction, considered as a stimulated Raman scattering process, is studied in different semiconductor mixtures: PbI2/TiO2, PbI2/Si and CdS/Si. Raman spectra recorded at excitation wavelengths of 514.5 and 488 nm for PbI2 and CdS, respectively, reveal a strong enhancement of the Raman lines peaked at 97 and 305 cm−1, evaluated by the ratio ITK/I300 K between the relative intensities of the spectra recorded in the temperature range of 88–300 K. It is found that PbI2 and CdS exhibit a decrease in the Raman intensity modes with decreasing temperature, while in TiO2 and Si an increase in the Raman lines intensities peaked at 138 and 520 cm−1 is observed. This behavior can be explained by an energy transfer process from PbI2 or CdS towards TiO2 and Si. This explanation is supported by the schematic potential energy levels diagram obtained from the density of states, which is calculated using the density functional theory. According to this energy levels diagram, the electrons are expected to migrate directly from the conduction band (CB) energetic levels of the PbI2 and CdS towards the CB levels of TiO2 and Si.

The influence of brand schematicity on the importance of product cues: self-purchasing versus gift-giving situations

PurposeThe purpose of this research is to investigate the influence of self-purchasing versus gift-giving situations on the importance of product cues and the moderating effect of brand schematicity.Design/methodology/approachData were collected via an online survey of 285 French consumers for wine and 139 French consumers for whisky. The interaction effect of the gift-giving situation and brand schematicity on the importance of product cues was then investigated.FindingsThe results differed, depending on the importance of brand cue. For the whisky category (high brand importance), brand schematicity had no influence on the importance of cues. For the wine category (low brand importance), brand schematicity moderated the influence of the gift-giving situation on the importance of extrinsic cues such as commercial brand. Brand schematicity and the situation of gift-giving also influence the number of important cues which consumers take into account when making their choice. In low-involvement purchasing situations, brand-aschematic consumers use fewer choice criteria than brand-schematic consumers, whereas in high-involvement purchasing situations, regardless of their level of brand schematicity, consumers use the same number of criteria to make their selection.Practical implicationsWhen the commercial brand is a salient cue and regardless of the purchasing situation, it is important to provide information on the brand to consumers through any format, such as social media, leaflets, flash codes, in-store digital display, etc. When the commercial brand is not a salient cue, brand schematicity may be relevant to a segment of consumers because this consumer profile may need more information and will focus on the commercial brand. Brand managers could develop a specific approach to schematic consumers based on brand content, for example, brand managers could provide marketing materials (e.g. leaflets, flash codes, mobile apps) to retail store managers explaining the origin and value of the commercial brand. Consumers could also be provided with digital devices (such as tablets), which they could use to search for information according to these cues before choosing their product. Social media and online brand community could also provide more details about the brand and may provide an interactive area for discussions with consumers.Originality/valueThere has been little research on the effect of brand schematicity on the importance of product cues. To the authors’ knowledge, the interaction between brand schematicity and purchase according to product category has not previously been studied. The influence of brand schematicity changes depending on the importance given to brand cues.

The effects of expertise and brand schematicity on the perceived importance of choice criteria: a Bordeaux wine investigation

PurposeThe purpose of this research is to understand the effects of expertise and brand schematicity on the perceived importance of choice criteria in the context of purchasing red wine purchase.Design/methodology/approachData were collected via an online survey of 307 French wine consumers. The interaction effects of expertise and brand schematicity on the importance assigned to choice criteria were then investigated.FindingsFirst, the results show that commercial brand is more important for brand-schematic consumers (novice and expert) than for brand-aschematic (novice and expert) consumers. Second, to make their choice, brand-schematic consumers place a greater reliance on quality cues than brand-aschematic consumers, whether they are novices or experts. Third, brand-aschematic novice consumers are only interested in two quality cues [Appellation d'Origine Contrôlée (AOC) label and wine category], but French brand-schematic novice and brand-aschematic expert consumers look for five quality cues (AOC label, wine category, vintage, commercial brand and place of bottling). Fourth, brand-schematic expert consumers take into account all quality cues.Practical implicationsThe individual characteristics of consumers, that is, level of expertise and schematicity, influence the importance assigned to the information contained on the label. Care should be taken when designing a wine label, especially when consumers make their purchases in supermarkets and have no opportunity to seek advice. To convince these customers, it is essential that the font and size of the label ensure that the AOC label, wine category, vintage, commercial brand and place of bottling can be easily read. Brand-schematic consumers are interested in many quality cues to make their choice, and therefore, such information should be available in supermarkets (e.g. flyers and posters). Managers should also focus on brand content strategy to influence and hit brand-aschematic consumers.Originality/valueThere has been little research on the effect of brand schematicity on the importance of choice criteria. The interaction of brand schematicity and degree of expertise regarding product category has not been previously studied in relation to wine selection. Brand schematicity may be used as a segmentation criterion by managers in communication campaigns and brand content strategies.

Levels of metaphor

AbstractWhat is the appropriate conceptual structure involved in conceptual metaphors? Various authors offer a large number of terms to discuss the issue. While domain is the most common term, many others are also used, including frame, image schema, cognitive model, idealized cognitive model, scene, schema, scenario, etc. The problem is compounded by the fact that the terms mean different things to different researchers. The main goal of the paper is to create some clarity in this terminological and theoretical confusion. I propose that conceptual metaphors simultaneously involve conceptual structures, or units, on four levels of schematicity: the level of image schemas, the level of domains, the level of frames, and the level of mental spaces. I call the resulting framework the “multi-level view of conceptual metaphor.” The multi-level view of metaphor can provide us with insights into a number of problems that have been raised and debated in the CMT literature. I show that the study of metaphor within such a framework can legitimately be pursued on the four levels of schematicity and that no level can be singled out as the only appropriate level of analysis.

ZnO:Cu nanorods with visible luminescence: copper induced defect levels and its luminescence dynamics

In this work, we report the synthesis of ZnO:Cu nanoparticles with rod-like morphology using co-precipitation method. X-ray diffraction analysis indicated that these ZnO:Cu nanoparticles has wurtzite structure with preferential growth along (1 0 1) crystal plane. The formation of additional defect levels in these particles on doping with Cu was investigated using Raman and fluorescence spectroscopy. The increase in intensity of E1 (LO) mode observed at ~580 cm−1 in the Raman spectra of ZnO:Cu nanoparticles, confirmed the formation of additional defect levels in these nanoparticles on doping with Cu. The doping concentration was evident in the intensity of the additional Raman mode observed at ~280 cm−1 for the Cu doped nanoparticles. Photoluminescence spectra of Cu doped ZnO nanoparticles shows three visible emission peaks at 413, 435 and 531 nm along with a UV emission peak at 390 nm, whereas undoped ZnO nanoparticles showed only two peaks, at 389 and 582 nm. The shrinkage in band gap causing the emission of violet, blue and green colors on doping with Cu are attributed to the s-d and p-d exchange interactions between conduction band electrons of ZnO and localized d electrons of Cu ions, resulting in renormalization of band gap. The emission bands observed in these ZnO:Cu nanoparticles has been illustrated with a schematic energy level diagram.

Nanoelectronic Mixed-Signal System Design [Book Reviews

The book covers the entire spectrum of modern integrated circuit (IC) technologies from the design and simulation point of view, starting at the schematic level and progressing through to actual physical design. There are many senior- and graduate level textbooks centered on traditional digital very-large-scale integration (VLSI) design. The topic is robust, mature, and has been taught for decades. In parallel, there is a much smaller population of texts focused on analog IC design with an emphasis on designing specific modules, such as amplifiers, analog-to-digital and digital-to-analog converters, receivers, transmitters, filters, and other esoteric topics. Absent from the latter category of textbooks are the discussions of system-centered analog design geared toward integration into an SoC. The intersection of these two design disciplines is commonly known as mixed-signal or analog/mixed-signal (AMS) design, a topic that has received very little attention. There are only a handful of books on the subject, usually at very advanced levels; most are collections of loosely connected chapters or papers. This dearth of information is at odds with the fact that all IC design these days is AMS by virtue of the design methodologies developed and the systems themselves: pure digital systems, even though still tremendously useful for computation, do not reflect daily usage of commodity electronics dictated by our connected society. This book covers the entire spectrum of modern IC technologies from the design and simulation point of view, starting at the schematic level and progressing through to actual physical design, including postlayout simulation and design optimization, always with a systems emphasis. The audience for this massive and authoritative treatise includes those interested in AMS IC design, particularly at the nano level, and the book also addresses the needs of everyone in that scope: college seniors, master’s and Ph.D. students as well as practicing engineers, designers, and computer-aided design developers. It can be used both as a text and reference book at the same time, since it covers an immense amount of state-of-the-art material.

CH3NH3PbI3, A Potential Solar Cell Candidate: Structural and Spectroscopic Investigations.

Hybrid organic-inorganic metal halides of the type CH3NH3PbX3 have emerged as potential materials for photovoltaic applications. In this paper we discuss structural, electronic, and optical spectroscopy investigations performed on high quality single crystals of CH3NH3PbI3. Our results conclusively suggest that CH3NH3PbI3 crystallizes in centrosymmetric space group and the methylammonium moiety exhibits disordered packing at room temperature. Extracted values of the exciton binding energy, the electron-phonon coupling constant, and the schematic energy level diagram constructed from the emission broadening, Raman, and photoemission spectroscopy measurements clearly show the potential of this system in photovoltaic applications.

Multimodal emissions from Tb3+/Yb3+ co-doped lithium borate glass: Upconversion, downshifting and quantum cutting

This paper reports the optical properties of Tb3+/Yb3+ co-doped lithium borate (LB) glass prepared by melt quench method. The absorption spectrum of the Yb3+ doped LB glass contains intense NIR band centered at 976nm due to 2F7/2→2F5/2 transition. The emission spectra of the prepared glasses have been monitored on excitation with 266, 355 and 976nm. The Yb3+ doped glass emits a broad NIR band centered at 976nm whereas the Tb3+ doped glass gives off visible bands on excitations with 266 and 355nm. When the Tb3+ and Yb3+ ions are co-doped together, the emission intensity in the visible region decreases whereas it increases in the NIR region significantly. The increase in the emission intensity in the NIR region is due to efficient cooperative energy transfer (CET) from Tb3+ to Yb3+ ions. The quantum cutting efficiency for Tb3+/Yb3+ co-doped glass has been calculated and compared for 266 and 355nm excitations. The quantum cutting efficiency is larger for 355nm excitation (137%). The Tb3+/Yb3+ co-doped LB glass also emits upconverted visible bands on excitation with 976nm. The mechanisms involved in the energy transfer have been discussed using schematic energy level diagram. The Tb3+/Yb3+ co-doped LB glass may be used in the optical devices and in solar cell for solar spectral conversion and behaves as a multi-modal photo-luminescent material.