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1
Kersting-Meuleman, Ann [Verfasser], and Maria Elisabeth [Akademischer Betreuer] Brockhoff. "Carl Halle - Sir Charles Hallé : ein europäischer Musiker / Ann Kersting-Meuleman. Betreuer: Maria Elisabeth Brockhoff." Frankfurt : Universitätsbibliothek Frankfurt am Main, 2012. http://d-nb.info/1043133240/34.
Повний текст джерела
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Fan, Zhaobing. "Geometric approach to Hall algebras and character sheaves." Diss., Kansas State University, 2012. http://hdl.handle.net/2097/14136.
Повний текст джерелаАнотація:
Doctor of PhilosophyDepartment of Mathematics
Zongzhu Lin
A representation of a quiver [Gamma] over a commutative ring R assigns an R-module to each vertex and an R-linear map to each arrow. In this dissertation, we consider R = k[t]/(t[superscript]n) and all R-free representations of [Gamma] which assign a free R-module to each vertex. The category, denoted by Rep[superscript]f[subscript] R([Gamma]), containing all such representations is not an abelian category, but rather an exact category. In this dissertation, we firstly study the Hall algebra of the category Rep[superscript]f[subscript] R([Gamma]), denote by [Eta](R[Gamma]), for a loop-free quiver [Gamma]. A geometric realization of the composition subalgebra of [Eta](R[Gamma]) is given under the framework of Lusztig's geometric setting. Moreover, the canonical basis and a monomial basis of this subalgebra are constructed by using perverse sheaves. This generalizes Lusztig's result about the geometric realization of quantum enveloping algebra. As a byproduct, the relation between this subalgebra and quantum generalized Kac-Moody algebras is obtained. If [Gamma] is a Jordan quiver, which is a quiver with one vertex and one loop, each representation in Rep[superscript]f[subscript] R([Gamma]), gives a matrix over R when we fix a basis of the free R-module. An interesting case arises when considering invertible matrices. It then turns out that one is dealing with representations of the group GL[subscript]m(k[t]/(t[superscript]n)). Character sheaf theory is a geometric character theory of algebraic groups. In this dissertation, we secondly construct character sheaves on GL[subscript]m(k[t]/(t[superscript]2)). Then we define an induction functor and restriction functor on these perverse sheaves.
3
Wikberg, Emma. "Non-abelian quantum Hall states and fractional charges in one dimension." Doctoral thesis, Stockholms universitet, Fysikum, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-89417.
Повний текст джерелаАнотація:
The fractional quantum Hall effect has, since its discovery around 30 years ago, been a vivid field of research—both experimentally and theoretically. In this thesis we investigate certain non-abelian quantum Hall states by mapping the two-dimensional system onto a thin torus, where the problem becomes effectively one-dimensional and hopping is suppressed, meaning that the classical electrostatic interaction dominates. The approach assists with a simplified view of ground states and their degeneracies, as well as of the nature of the fractionally charged, minimal excitations of the corresponding quantum Hall states. Similar models are also relevant for cold atoms trapped in one-dimensional optical lattices, where interaction parameters are available for tuning, which opens up for realizing interesting lattice states in controllable environments. The diverse applicability of the one-dimensional electrostatic lattice hamiltonian motivates the exploration of the systems and models treated in this work. In the absence of hopping or tunneling, the low-energy behavior of the one-dimensional lattice system is ultimately dependent on the nature of the electrostatic interaction present. For ordinary interactions such as Coulomb, the ground state at particle filling fraction ν= p/q has a well-known q-fold center-of-mass degeneracy and the elementary excitations are domain walls of fractional charge e* = ±e/q. These appear in abelian quantum Hall systems and are known since earlier. In this work, we show how other types of interaction give rise to increased ground state degeneracies and, as a result, to the emergence of split fractional charges recognized from non- abelian quantum Hall systems.At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 5: Manuscript.
4
Venkatachalam, Vivek. "Single Electron Probes of Fractional Quantum Hall States." Thesis, Harvard University, 2012. http://dissertations.umi.com/gsas.harvard:10478.
Повний текст джерелаАнотація:
When electrons are confined to a two dimensional layer with a perpendicular applied magnetic field, such that the ratio of electrons to flux quanta \((\nu)\) is a small integer or simple rational value, these electrons condense into remarkable new phases of matter that are strikingly different from the metallic electron gas that exists in the absence of a magnetic field. These phases, called integer or fractional quantum Hall (IQH or FQH) states, appear to be conventional insulators in their bulk, but behave as a dissipationless metal along their edge. Furthermore, electrical measurements of such a system are largely insensitive to the detailed geometry of how the system is contacted or even how large the system is... only the order in which contacts are made appears to matter. This insensitivity to local geometry has since appeared in a number of other two and three dimensional systems, earning them the classification of "topological insulators" and prompting an enormous experimental and theoretical effort to understand their properties and perhaps manipulate these properties to create robust quantum information processors. The focus of this thesis will be two experiments designed to elucidate remarkable properties of the metallic edge and insulating bulk of certain FQH systems. To study such systems, we can use mesoscopic devices known as single electron transistors (SETs). These devices operate by watching single electrons hop into and out of a confining box and into a nearby wire (for measurement). If it is initially unfavorable for an electron to leave the box, it can be made favorable by bringing another charge nearby, modifying the energy of the confined electron and pushing it out of the box and into the nearby wire. In this way, the SET can measure nearby charges. Alternatively, we can heat up the nearby wire to make it easier for electrons to enter and leave the box. In this way, the SET is a sensitive thermometer. First, by operating the SET as an electrometer, we measure the local charge of the \(\nu = 5/2\) FQH state. An immediate consequence of measuring fractionally quantized conductance plateaus is that the charge of local excitations should be a fraction of \(e\), the charge of an electron. The simplest charge that would be expected at \(\nu = 5/2\) would \(e/2\). However, if the charged particles that condense into the \(\nu = 5/2\) FQH state are paired, the expected local charge becomes \(e/4\). By watching these local charges being added to compressible puddles at \(\nu = 5/2\) and \(\nu = 5/7\), we find that the local charge at \(\nu = 5/2\) is indeed \(e/4\), indicating that objects of charge \(e\) are pairing to form the ground state of the system. This has implications for the future possibility of detecting non-Abelian braiding statistics in this state, and is described in detail in Chapter 2. By further monitoring how eagerly these \(e/4\) particles enter puddles as we increase the temperature, we can attempt to identify the presence of some excess entropy related to an unconventional degeneracy of their ground state. Such an entropy would be expected if the \(\nu = 5/2\) state exhibited non-Abelian braiding statistics. Progress on these experiments and prospects for building a quantum computer are presented in Chapter 3. Next, by operating the SET as a thermometer, we monitor heat flow along the compressible edge and through the bulk of IQH and FQH states. As an edge is heated and charge on that edge is swept downstream by the external magnetic field, we expect that charge to carry the injected energy in the same downstream direction. However, for certain FQH states, this is not the case. By heating an edge with a quantum point contact (QPC) and monitoring the heat transported upstream and downstream, we find that heat can be transported upstream when the edge contains structure related to \(\nu = 2/3\) FQH physics. Surprisingly, this can be present even when the bulk is in a conventional insulating (IQH) state. Additionally, we unexpectedly find that the \(\nu = 1\) bulk is capable of transporting heat, while the \(\nu = 2\) and \(\nu = 3\) bulk are not. These experiments are presented in Chapter 4. Finally, in Chapter 5, we describe preliminary work on a very different type of topological material, the quantum spin Hall (QSH) insulator. Here, the spin of electrons takes the place of the external magnetic field, creating edge states that propagate in both directions. Each of these edges behaves as an ideal one-dimensional mode, with predicted resistance \(h/e^2\). By creating well-defined regions where these modes can exist, we identify and characterize the conductance associated with topological edges.Physics
5
Milletari, Mirco. "Non-equilibrium transport in quantum hall edge states." Doctoral thesis, Universitätsbibliothek Leipzig, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-124556.
Повний текст джерелаАнотація:
This thesis deals with the study of transport properties of integer and fractional QH edge states and it is based on the work I performed during my Ph.D. studies. The focus of this thesis is on Luttinger liquids far from equilibrium and their relaxation dynamics. Since Boltzmann, a fundamental aspect of statistical mechanics has been the understanding of the emergence of an equilibrium state. Interactions play a crucial role in the thermalization process that drives a system through states described by the Gibbs equilibrium ensemble. Therefore, it seems counterintuitive that a strongly interacting system, such as the Luttinger liquid, should not present any relaxation dynamics. This peculiar fact is due to the integrability of the Luttinger model, i.e. the existence of an infinite number of conserved quantities that precludes the equilibration process. However, in the past few years it has become clear that integrable systems can present some kind of relaxation, even though not towards the Gibbs equilibrium ensemble. Remarkably, the necessity of correctly taking into account some particular non-equilibrium configurations, also revealed the necessity of modifying bosonization, a technique widely used to study strongly interacting systems in one dimension. In this work we focus on three different cases:
• Relaxation of high energy electrons injected in a ν = 1/3 chiral Luttinger liquid and in a standard Luttinger liquid.
• Heating and the emergence of effective temperatures in a Quantum Hall system at fractional filling fraction ν = 2/3 partitioned by a Quantum Point Contact.
• Effect of relaxation on shot-noise measurement of the quasi-particle charge in a ν = 2 QH state.
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Stepanov, Petr. "Spin and Charge Transport in Monolayer and Trilayer Graphene in the Quantum Hall Regime." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1532103607994675.
Повний текст джерела
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Zhou, Hengyun S. B. Massachusetts Institute of Technology. "Tailoring light with photonic crystal slabs : from directional emission to topological half charges." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/105643.
Повний текст джерелаАнотація:
Thesis: S.B., Massachusetts Institute of Technology, Department of Physics, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 75-80).
Photonic crystal slabs are a versatile and important platform for molding the flow of light. In this thesis, we consider ways to control the emission of light from photonic crystal slab structures, specifically focusing on directional, asymmetric emission, and on emitting light with interesting topological features. First, we develop a general coupled-mode theory formalism to derive bounds on the asymmetric decay rates to top and bottom of a photonic crystal slab, for a resonance with arbitrary in-plane wavevector. We then employ this formalism to inversion symmetric structures, and show through numerical simulations that asymmetries of top-down decay rates exceeding 104 can be achieved by tuning the resonance frequency to coincide with the perfectly transmitting Fabry-Perot frequency. The emission direction can also be rapidly switched from top to bottom by tuning the wavevector or frequency. We then consider the generation of Mobius strips of light polarization, i.e. vector beams with half-integer polarization winding, from photonic crystal slabs. We show that a quadratic degeneracy formed by symmetry considerations can be split into a pair of Dirac points, which can be further split into four exceptional points. Through calculations of an analytical two-band model and numerical simulations of two-dimensional photonic crystals and photonic crystal slabs, we demonstrate the existence of isofrequency contours encircling two exceptional points, and show the half-integer polarization winding along these isofrequency contours. We further propose a realistic photonic crystal slab structure and experimental setup to verify the existence of such Mobius strips of light polarization.
by Hengyun Zhou.
S.B.
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Cakir, Halil [Verfasser], and Zoltán [Akademischer Betreuer] Harman. "Quantum Electrodynamic Theory of Few-Electron Highly Charged Ions / Halil Cakir ; Betreuer: Zoltán Harman." Heidelberg : Universitätsbibliothek Heidelberg, 2020. http://d-nb.info/1213902452/34.
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Thirion, Damien. "Modulation des propriétés d'isomères de diSpirofluorène-indénofluorène pour des applications en diodes électroluminescentes organiques bleues." Rennes 1, 2011. https://hal-univ-rennes1.archives-ouvertes.fr/tel-01217848.
Повний текст джерелаАнотація:
Ce travail porte sur la synthèse et l'étude de molécules d'architecture 3π-2spiro, DiSpiroFluorène-IndénoFluorène (DSF-IF), de structures différentes. La finalité de ces composés est leur utilisation en tant que couche émissive de lumière bleue dans des diodes électroluminescentes organiques (OLED). Le premier chapitre bibliographique décrit tout d'abord le principe de fonctionnement des OLEDs et leurs différentes structures. Il se poursuit par la description de différentes approches d'ingénierie moléculaires visant à obtenir des molécules ambipolaires capables d'être utilisées dans des dispositifs monocouches. Le second chapitre concerne l'étude de deux familles d'isomères de DSF-IF obtenus au travers d'un seul et même intermédiaire de synthèse. La structure différente du corps indénofluorène, (1,2-b) ou (2,1-a), entraîne des propriétés différentes, en particuliers liées à des interactions π-π intramoléculaires dans les isomères de géométrie (2,1-a). Le troisième chapitre est consacré à la mise au point de DSF-IF fonctionnalisés par des groupements donneur et/ou accepteurs d'électrons. L'impact de l'ajout de groupements transporteurs de charges sur le corps DSF-IF est discuté et en particulier les phénomènes de transfert de charge intramoléculaires. Enfin, le dernier chapitre traite de l'étude de certaines molécules synthétisées précédemment en tant que couches émissives dans des OLEDsThis work is focused on the synthesis and study of 3π-2spiro molecules, DiSpiroFluorene-IndenoFluorene (DSF-IF), having different structures. These compounds are aimed to be used as blue light emitting layer in OLED. The first chapter describes the working principles of OLEDs and their different structures. It focuses then on different approaches of molecular engineering towards ambipolar molecules that can be used in single layer devices. The second chapter is devoted to the study of two different families of DSF-IF isomers that are obtained through one and the same synthetic intermediate. The different structure of the indenofluorene backbone, (1,2-b) or (2,1-a), leads to different properties, mainly because of intramolecular π-π interactions. The third chapter is related to the development of functionalized DSF-IF with electron donor and/or acceptor groups. The impact of the electron donor or acceptor groups substituted on the DSF-IF are discussed, especially the intramolecular charge transfer phenomena. In the last part, some of these new molecules have been tested as emitting layers in OLEDs
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Grissonnanche, Gaël. "Une fable de phases en interaction dans les cuprates supraconducteurs contée par le transport thermique." Thèse, Université de Sherbrooke, 2016. http://hdl.handle.net/11143/8560.
Повний текст джерелаАнотація:
Cette thèse traite l'interaction d'ordres en compétition dans les cuprates supraconducteurs dopés en trous; il sera question de supraconductivité et d'ordre de charge. Dans une première étude, la conductivité thermique $\kappa_{\rm xx}$ sous forts champs magnétiques du cuprate YBCO est utilisée pour mesurer le champ critique $H_{\rm c2}$. Cette expérience révèle la forte compétition entre la supraconductivité et l'ordre de charge dans ces matériaux dopés en trous. Ce résultat représente la première mesure directe de champ critique $H_{\rm c2}$ dans cette famille de supraconducteurs et démontre l'absence de liquide de vortex à température nulle. Dans une deuxième étude, la combinaison de l'effet Hall thermique $\kappa_{\rm xy}$ et de mesures électriques sous forts champs magnétiques permet l'exploration de la loi de Wiedemann-Franz dans le cuprate YBCO. En démontrant que cette loi est satisfaite au-dessus du champ magnétique critique $H_{\rm c2}$ déterminé lors du premier projet, cette expérience montre qu'il ne reste pas de supraconductivité au-dessus du champ magnétique critique et que l'état normal des cuprates sous-dopés est métallique. Dans une troisième étude, l'effet Hall thermique $\kappa_{\rm xy}$ est utilisé pour sonder la surface de Fermi d'un matériau dans sa phase supraconductrice. Pour les cuprates sous-dopés en trous, ce projet révèle qu'il n'y a pas de reconstruction de la surface de Fermi en champ nul par l'ordre de charge à courte portée. Cette expérience pionnière représente ainsi le trait d'union manquant entre de nombreux résultats qui pourtant parurent contradictoires au premier abord.
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Valette, Matthieu. "Etudes de dynamique faisceau pour les accélérateurs IFMIF." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS242/document.
Повний текст джерелаАнотація:
Dans le cadre de l'Approche Elargie pour la Fusion conclue entre le Japon et l'Europe, le projet IFMIF (International Fusion Materials Irradiation Facility) a été lancé pour l'étude des futurs matériaux pour la fusion qui devront résister à d'intenses flux de neutrons. Un composant majeur en est son ensemble de deux accélérateurs à très haute puissance (2×5 MW) qui produit le flux de neutrons en bombardant une cible de Lithium avec un faisceau de Deutérium à une énergie de 40 MeV. Vues ces spécifications ambitieuses, une première phase appelée EVEDA (Engineering Validation and Engineering Design Activity) prévoit l'étude et la réalisation d'un accélérateur prototype à l'échelle un jusqu'à 9 MeV au Japon. Le travail de cette thèse concerne le domaine de la Physique des Accélérateurs. Il consiste en des études de dynamique faisceau pour l'accélérateur prototype LIPAc, caractérisé par une intensité et une puissance jamais encore réalisées, exigeant de ce fait des qualités de faisceau exceptionnelles. Les caractéristiques de cet accélérateur, font qu'il requiert de nombreuses études et simulations pour toutes les étapes de sa mise en service. En parallèle, des études de fond sur les interactions coeur-halo et les effets de la charge d'espace dans les accélérateurs intenses, seront aussi menées. En particulier une nouvelle définition du halo d'un faisceau de particules, adaptée à l'étude de ces accélérateurs sera proposée et appliquéeAs part of the Broader Approach to Fusion concluded between Japan and Europe, the IFMIF (International Fusion Materials Irradiation Facility) project was launched for the study of future fusion materials resisting intense neutron fluxes. A major component of it is the couple of twin high power accelerators (2 × 5 MW) which will produce the neutron flux by bombarding a Lithium target with a deuterium beam at an energy of 40 MeV. Considering these ambitious specifications, a first phase called EVEDA (Engineering Validation and Engineering Design Activity) is ongoing to provide the design and construction of an up to scale prototype accelerator to an energy of 9 MeV in Japan. The work of this thesis belongs to the field of Accelerators Physics. It consists of beam dynamics studies for the prototype accelerator LIPAc, characterized by unprecedented current and power, thereby requiring outstanding beam quality. The characteristics of this accelerator, makes many studies and simulations for all stages of its commissioning required. Concurrently, background studies on core-halo interactions and on the effects of space charge on high current beams will also be conducted. In particular a new definition of the halo of a particle beam, adapted to the study of these accelerators will be proposed and implemented
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Barney, Bradley John. "Accounting for Additional Heterogeneity: A Theoretic Extension of an Extant Economic Model." BYU ScholarsArchive, 2007. https://scholarsarchive.byu.edu/etd/1223.
Повний текст джерелаАнотація:
The assumption in economics of a representative agent is often made. However, it is a very rigid assumption. Hall and Jones (2004b) presented an economic model that essentially provided for a representative agent for each age group in determining the group's health level function. Our work seeks to extend their theoretical version of the model by allowing for two representative agents for each age—one for each of “Healthy” and “Sick” risk-factor groups—to allow for additional heterogeneity in the populace. The approach to include even more risk-factor groups is also briefly discussed. While our “extended” theoretical model is not applied directly to relevant data, several techniques that could be applicable were the relevant data to be obtained are demonstrated on other data sets. This includes examples of using linear classification, fitting baseline-category logit models, and running the genetic algorithm.
13
Hällman, Oscar. "DC Charging of Heavy Commercial Plug-in Hybrid Electric Vehicles." Thesis, Linköpings universitet, Datorteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-119618.
Повний текст джерелаАнотація:
A solution to reduce exhaust emissions from heavy commercial vehicles are to haul the vehicles completely or partially electric. This means that the vehicle must contain a significant electric energy source. The large capacity of the energy source causes the vehicle to either sacrifice a large part of its up time to charge the source or apply a higher charge power at the cost of power losses and lifetime of the energy source. This thesis contains a pre-study of high-power DC-charge of hybrid batteries from existing infrastructure suited to electric hybrid cars. Following parts are included in the thesis: modeling of a battery pack and a DC-DC converter, formulation of a MPC controller for the battery pack, analysis of charging strategies and battery restrictions through simulations. The thesis results shows that a longer charging time increases the energy efficiency and reduces the degradation in the battery. It also shows that a charging strategy similar to constant-current-constant-voltage charging should be used for a full charge of an empty battery.
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Typltová, Hana. "Městská knihovna, Lausanne." Master's thesis, Vysoké učení technické v Brně. Fakulta architektury, 2013. http://www.nusl.cz/ntk/nusl-215986.
Повний текст джерела
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Roquais, Jean-Michel. "Implantation ionique d'accepteurs dans le phosphure d'indium : caracterisation physico-chimiques et electriques." Rennes, INSA, 1986. http://www.theses.fr/1986ISAR0004.
Повний текст джерелаАнотація:
Etude du dopage p**(+) dans inp par implantation d'accepteurs peu profonds: be, mg, zn, hg. Caracterisation du desordre cree par diffusion raman; etude au degre de recristallisation apres recuit d'implantation. Etude par emission photoelectronique rx d'une contamination de surface. Determination de profils d'impuretes. Les profils de concentration de porteurs ont ete analyses par effet hall et mesures electrochimiques. Etude du coefficient de diffusion du zinc par la methode de boltzmann-matano
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AYME, CARRIE NATHALIE. "Analyse des effets du vent sur les structures baties : constructions basses et structures elancees." Nantes, 1987. http://www.theses.fr/1987NANT2051.
Повний текст джерелаАнотація:
Methode de calcul d'une force statique equivalente pour representer l'action du vent sur une structure basse type (halle industrielle), avec determination de coefficients de pression dans une approche reglementaire. Pour les structures elevees, ou l'aspect dynamique est preponderant, developpement d'un logiciel a partir du modele vickery-basu (structure elancee a section circulaire); determination des parametres aerodynamiques a partir de donnees experimentales
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Bosc, Fabien. "Centre DX et mobilité électronique dans les superréseaux GaAs/AlAs-application capteur de pression." Montpellier 2, 1997. http://www.theses.fr/1997MON20169.
Повний текст джерелаАнотація:
L'objet de ce travail est de montrer l'interet que peuvent presenter les superreseaux gaas/alas pour la realisation d'un capteur de pression hydrostatique fonctionnant entre la temperature ambiante et 200c, dans la gamme de pression comprise entre 0 et 2kbar. Ce travail fait suite a une etude realisee sur l'alliage gaalas dans laquelle avait ete demontree la grande sensibilite de ce materiau a la pression pour une concentration en aluminium comprise entre 25% et 40%. Pour reduire la sensibilite a la temperature du dispositif initialement propose, l'idee avancee au laboratoire, a ete d'utiliser un pseudo-alliage gaas/alas dont les proprietes electroniques pouvaient etre mieux controlees, tant du point de vue de la structure de bande que du mode de dopage. Pour cela, nous avons dans un premier temps, etabli les modeles permettant d'optimiser les structures adaptees aux objectifs recherches, sans oublier de tenir compte des limites technologiques imposees par les fabricants. Une fois les structures realisees, nous nous sommes interesses a la comprehension des effets du dopage sur les proprietes electroniques du superreseau (resistivite, mobilite, concentration de porteurs). Nous avons alors utilise une methode experimentale couplant les techniques du transport a celles des hautes pressions. L'equipement utilise nous permet d'etudier, sur une large gamme de temperature (77k-450k), les proprietes electriques d'un meme echantillon dont on modifie la structure de bande par application de la pression. Les resultats ont ensuite ete confrontes au modele que nous avons etabli, dans lequel etati pris en compte le caractere particulier du centre dx qui controle la conduction. Une bonne comprehension des proprietes electriques du centre dx necessite une bonne connaissance des mecanismes de diffusion et de correlations des charges (2 etats de charges d#+ et dx#- du centre dx) qui controlent la valeur de la mobilite de hall. La aussi, il existe une difference notable entre l'alliage (gaal)as et le superreseau gaas-alas. Sur la base des resultats obtenus, nous avons pu montrer la validite de l'idee avancee selon laquelle les superreseaux etaient plus adaptes que l'alliage pour realiser des capteurs performants.
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Grimaldi, Amarine. "L'institution harmonique (ca. 1640-1647) de Charles Guillet." Thesis, Tours, 2013. http://www.theses.fr/2013TOUR2020.
Повний текст джерелаАнотація:
Cette thèse porte sur l’Institution harmonique, un traité manuscrit composé par Charles Guillet entre 1640 et 1647, dédié à l’archiduc Léopold-Guillaume. Une étude introductoire précède la transcription de la dédicace, de la préface et du premier livre (le seul qui subsiste). Elle met en lumière l’auteur Charles Guillet (ca. 1575-1654), une figure originale mais peu connue dans le paysage musical et apporte des éclairages sur la source manuscrite (notamment organisation, contenu et dessein théorique). La construction de son discours est enfin analysée à travers l’usage des sources (choix des autorités et compilation de deux « phares harmoniques » qu’étaient Zarlino et Salinas). Par la mise en scène de controverses, Guillet démontre la supériorité de la division syntone sur la diatone et justifie la théorie modale de Zarlino. Dans le premier livre sur « la Theorie, ou Speculative Musicale », la théorie arithmétique des rapports et des proportions est appliquée aux intervalles puis aux questions pratiques du tempéramentThis dissertation deals with the Institution Harmonique, a hand written treatise, composed by Charles Guillet between 1640 and 1647, dedicated to Archduke Leopold Wilhelm. An introductory study precedes the transcription of the dedication, preface and Part 1 (the only one remaining to this day). It introduces author Charles Guillet (ca. 1575-1654), an original yet poorly known figure of the musical scene. You will find some specifications regarding the hand-written source (organisation, content and theoretic purpose). I will analyse the construction of discourse through the use of the various sources (choice of authorities and compilation of Zarlino and Salinas, two « harmonic lighthouses ». By staging of controversies, Guillet demonstrates the superiority of syntonic tuning on Pythagorean tuning and justifies the zarlinian modal theory. In the Part 1 on « The Theory, or musical speculative », the arithmetic theory of ratios and proportions is applied to the intervals then to the practical questions regarding temperament
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Giesen, Gaelle. "Dark Matter Indirect Detection with charged cosmic rays." Thesis, Paris 11, 2015. http://www.theses.fr/2015PA112160/document.
Повний текст джерелаАнотація:
Les preuves pour l'existence de la matière noire (MN), sous forme d'une particule inconnue qui rempli les halos galactiques, sont issues d'observations astrophysiques et cosmologiques: son effet gravitationnel est visible dans les rotations des galaxies, des amas de galaxies et dans la formation des grandes structures de l'univers. Une manifestation non-gravitationnelle de sa présence n'a pas encore été découverte. L'une des techniques les plus prometteuse est la détection indirecte de la MN, consistant à identifier des excès dans les flux de rayons cosmiques pouvant provenir de l'annihilation ou la désintégration de la MN dans le halo de la Voie Lactée. Les efforts expérimentaux actuels se focalisent principalement sur une gamme d'énergie de l'ordre du GeV au TeV, où un signal de WIMP (Weakly Interacting Massive Particles) est attendu. L'analyse des mesures récentes et inédites des rayons cosmiques chargés (antiprotons, électrons et positrons) et leurs émissions secondaires et les améliorations des modèles astrophysiques sont présentées.Les données de PAMELA sur les antiprotons contraignent l'annihilation et la désintégration de la MN de manière similaire (et même légèrement meilleurs) que les contraintes les plus fortes venant des rayons gamma, même dans le cas où les énergies cinétiques inférieures à 10 GeV sont écartées. En choisissant des paramètres astrophysiques différents (modèles de propagation et profils de MN), les contraintes peuvent changer d'un à deux ordres de grandeur. Pour exploiter la totalité de la capacité des antiprotons à contraindre la MN, des effets précédemment négligés sont incorporés et se révèlent être importants dans l'analyse des données inédites de AMS-02 : ajouter les pertes d'énergie, la diffusion dans l'espace des moments et la modulation solaire peut modifier les contraintes, même à de hautes masses. Une mauvaise interprétation des données peut survenir si ces effets ne sont pas pris en compte. Avec les flux de protons et d'hélium exposé par AMS-02, le fond astrophysique et ces incertitudes du ratio antiprotons sur protons sont réévalués et comparés aux données inédites de AMS-02. Aucune indication pour un excès n'est trouvé. Une préférence pour un halo confinant plus large et une dépendance en énergie du coefficient de diffusion plus plate apparaissent. De nouvelles contraintes sur l'annihilation et la désintégration de la MN sont ainsi dérivés.Les émissions secondaires des électrons et des positrons peuvent aussi contraindre l'annihilation et la désintégration de la MN dans le halo galactique : le signal radio dû à la radiation synchrotron des électrons et positrons dans le champs magnétique galactique, les rayons gamma des processus de bremsstrahlung avec le gas galactique et de Compton Inverse avec le champs radiatif interstellaire sont considérés. Différentes configurations de champs magnétique galactique et de modèles de propagation et des cartes de gas et de champs radiatif interstellaire améliorés sont utilisées pour obtenir des outils permettant le calculs des émissions synchrotrons et bremsstrahlung venant de MN de type WIMP. Tous les résultats numériques sont incorporés dans la dernière version du Poor Particle Physicist Coookbook for DM Indirect Detection (PPPC4DMID).Une interprétation d'un possible excès dans les données de rayons gamma de Fermi-LAT au centre galactique comme étant dû à l'annihilation de MN en canaux hadronique et leptonique est analysée. Dans une approche de messagers multiples, le calcul des émissions secondaires est amélioré et se révèle être important pour la détermination du spectre pour le canal leptonique. Ensuite, les limites provenant des antiprotons sur l'annihilation en canal hadronique contraignent sévèrement l'interprétation de cet excès comme étant dû à la MN, dans le cas de paramètres de propagation et de modulation solaire standards. Avec un choix plus conservatif de ces paramètres elles s'assouplissent considérablementOverwhelming evidence for the existence of Dark Matter (DM), in the form of an unknownparticle filling the galactic halos, originates from many observations in astrophysics and cosmology: its gravitational effects are apparent on galactic rotations, in galaxy clusters and in shaping the large scale structure of the Universe. On the other hand, a non-gravitational manifestation of its presence is yet to be unveiled. One of the most promising techniques is the one of indirect detection, aimed at identifying excesses in cosmic ray fluxes which could possibly be produced by DM annihilations or decays in the Milky Way halo. The current experimental efforts mainly focus in the GeV to TeV energy range, which is also where signals from WIMPs (Weakly Interacting Massive Particles) are expected. Focussing on charged cosmic rays, in particular antiprotons, electrons and positrons, as well as their secondary emissions, an analysis of current and forseen cosmic ray measurements and improvements on astrophysical models are presented. Antiproton data from PAMELA imposes contraints on annihilating and decaying DM which are similar to (or even slightly stronger than) the most stringent bounds from gamma ray experiments, even when kinetic energies below 10 GeV are discarded. However, choosing different sets of astrophysical parameters, in the form of propagation models and halo profiles, allows the contraints to span over one or two orders of magnitude. In order to exploit fully the power of antiprotons to constrain or discover DM, effects which were previously perceived as subleading turn out to be relevant especially for the analysis of the newly released AMS-02 data. In fact, including energy losses, diffusive reaccelleration and solar modulation can somewhat modify the current bounds, even at large DM masses. A wrong interpretation of the data may arise if they are not taken into account. Finally, using the updated proton and helium fluxes just released by the AMS-02 experiment, the astrophysical antiproton to proton ratio and its uncertainties are reevaluated and compared to the preliminarly reported AMS-02 measurements. No unambiguous evidence for a significant excess with respect to expectations is found. Yet, some preference for thicker halos and a flatter energy dependence of the diffusion coefficient starts to emerge. New stringed constraints on DM annihilation and decay are derived. Secondary emissions from electrons and positrons can also be used to constrain DM annihilation or decay in the galactic halo. The radio signal due to synchrotron radiation of electrons and positrons on the galactic magnetic field, gamma rays from bremsstrahlung processes on the galactic gas densities and from Inverse Compton scattering processes on the interstellar radiation field are considered. With several magnetic field configurations, propagation scenarios and improved gas density maps and interstellar radiation field, state-of-art tools allowing the computaion of synchrotron and bremssttrahlung radiation for any WIMP DM model are provided. All numerical results for DM are incorporated in the release of the Poor Particle Physicist Coookbook for DM Indirect Detection (PPPC4DMID). Finally, the possible GeV gamma-ray excess identified in the Fermi-LAT data from the Galactic Center in terms of DM annihilation, either in hadronic or leptonic channels is studied. In order to test this tantalizing interprestation, a multi-messenger approach is used: first, the computation of secondary emisison from DM with respect to previous works confirms it to be relevant for determining the DM spectrum in leptonic channels. Second, limits from antiprotons severely constrain the DM interpretation of the excess in the hadronic channel, for standard assumptions on the Galactic propagation parameters and solar modulation. However, they considerably relax if more conservative choices are adopted
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Sibari, Hassane. "Transport classique et quantique dans les hétérojonctions GaAlAs/GaAs : rôle des états d'interface." Montpellier 2, 1992. http://www.theses.fr/1992MON20251.
Повний текст джерелаАнотація:
L'analyse des phenomenes de transport classique et quantique dans les heterojonctions gaalas-gaas laisse envisager l'existence d'etats additionnels, situes a l'interface de l'heterojonction. En effet, d'une part, l'analyse de la mobilite des electrons du canal 2d revele que les valeurs theoriques de la mobilite sont toujours superieures aux valeurs experimentales. Ceci met en evidence l'existence d'un mode de diffusion supplementaire que nous attribuons aux etats situes a l'interface de l'heterojonction. D'autre part, l'etude de l'equilibre des charges dans l'heterojonction montre que le transfert calcule d'electrons, depuis les etats donneurs de gaalas vers le canal bidimensionnel de gaas est toujours inferieur a la valeur experimentale. Nous expliquons cette difference par la contribution au transfert des etats d'interface de type donneur. Ceci permet egalement d'expliquer les variations (decroissance) de la densite d'electrons ns avec la temperature entre 77k et 4. 2k (on tient compte du caractere metastable des donneurs si de la couche de gaalas dope. Nous etudions par la suite l'effet hall quantique. Nous montrons que l'hypothese d'un systeme 2d d'electrons non isole permet d'expliquer parfaitement les resultats experimentaux sans avoir recours au concept de localisation. Les etats d'interface peuvent encore une fois jouer le role de reservoir pour le systeme 2d et permettent le freinage du niveau de fermi. Condition necessaire pour la formation des plateaux de hall
21
Sakib, Ashiq Adnan. "Formal Modeling and Verification Methodologies for Quasi-Delay Insensitive Asynchronous Circuits." Diss., North Dakota State University, 2019. https://hdl.handle.net/10365/29896.
Повний текст джерелаАнотація:
Pre-Charge Half Buffers (PCHB) and NULL convention Logic (NCL) are two major commercially successful Quasi-Delay Insensitive (QDI) asynchronous paradigms, which are known for their low-power performance and inherent robustness. In industry, QDI circuits are synthesized from their synchronous counterparts using custom synthesis tools. Validation of the synthesized QDI implementation is a critical design prerequisite before fabrication. At present, validation schemes are mostly extensive simulation based that are good enough to detect shallow bugs, but may fail to detect corner-case bugs. Hence, development of formal verification methods for QDI circuits have been long desired. The very few formal verification methods that exist in the related field have major limiting factors. This dissertation presents different formal verification methodologies applicable to PCHB and NCL circuits, and aims at addressing the limitations of previous verification approaches. The developed methodologies can guarantee both safety (full functional correctness) and liveness (absence of deadlock), and are demonstrated using several increasingly larger sequential and combinational PCHB and NCL circuits, along with various ISCAS benchmarks.National Science Foundation (Grant No. CCF-1717420)
22
Bono, Jason S. "First Time Measurements of Polarization Observables for the Charged Cascade Hyperon in Photoproduction." FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1520.
Повний текст джерелаАнотація:
The parity violating weak decay of hyperons offers a valuable means of measuring their polarization, providing insight into the production of strange quarks and the matter they compose. Jefferson Lab’s CLAS collaboration has utilized this property of hyperons, publishing the most precise polarization measurements for the Λ and Σ in both photoproduction and electroproduction to date. In contrast, cascades, which contain two strange quarks, can only be produced through indirect processes and as a result, exhibit low cross sections thus remaining experimentally elusive.
At present, there are two aspects in cascade physics where progress has been minimal: characterizing their production mechanism, which lacks theoretical and experimental developments, and observation of the numerous excited cascade resonances that are required to exist by flavor SU(3)F symmetry. However, CLAS data were collected in 2008 with a luminosity of 68 pb−1 using a circularly polarized photon beam with energies up to 5.45 GeV, incident on a liquid hydrogen target. This dataset is, at present, the world’s largest for meson photoproduction in its energy range and provides a unique opportunity to study cascade physics with polarization measurements.
The current analysis explores hyperon production through the γp → K+K+Ξ− reaction by providing the first ever determination of spin observables P, Cx and Cz for the cascade. Three of our primary goals are to test the only cascade photoproduction model in existence, examine the underlying processes that give rise to hyperon polarization, and to stimulate future theoretical developments while providing constraints for their parameters. Our research is part of a broader program to understand the production of strange quarks and hadrons with strangeness. The remainder of this document discusses the motivation behind such research, the method of data collection, details of their analysis, and the significance of our results.
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Mowafy, Waheed Mohamed Awad. "Modern Arabic literary biography : a study of character portrayal in the works of Egyptian biographers of the first half of the twentieth century, with special reference to literary biography." Thesis, University of Leeds, 1999. http://etheses.whiterose.ac.uk/703/.
Повний текст джерелаАнотація:
In Chapter one, I presented a comparative definition of the meaning of Sirah (PI.Siyar), Tarjamah (Pl. Tarajim), Manaqib, Tabaqat and Maghazi as they were understood in antiquity. I also showed how the meaning of Sirah in modern times has only narrowly developed. Although the method of biographical writing continuously developed in Europe, it hardly progressed in Modem Arabic Literature. The only exception was seen in the writings by the pioneers of enlightenment in Egypt at the beginning of the twentieth century. This change of direction relied on borrowing European methodology in biographical writing. In chapter two, I reviewed the early attempts at writing biographies in the nineteenth century by Abd al Rahman al- Jabarti and Ali Mubarak. Although both were the first pioneers in this respect, yet they followed the footpath of classical approach above all that of al-Maqarizi from whom -Ali Mubarak derived inspiration in his book Al-Khitat al-Tawfiqiyyah. In chapter three, I studied the twentieth century, starting with traditional biography writers who could not employ European methodologies and whose writings oscillated between biographical notes and biographical sketches; or whose texts were more of a literary study than a biography proper. In chapters four to nine, I selected the most renowned, productive writers who best represented methodologies of biography writing. Perhaps certain writers have not been mentioned in this period of study. This is not out of negligence but simply because their texts were totally out of reach, or their writings did not exhibit the required literary criteria. All methodologies representing the theory of biography writing in Egypt have been analysed in these chapters. All, in fact, form a digestion or assimilation of French,English and German schools. In Egypt, Taha Husayn is considered the chairman of the French school, al-Mazini and al-Aqqad of the English/German schools, al-Nuwaihi of the psychoanalytical/anatomical school and Sidqi who employed both. By contrast, al Iryan was the trailblazer of the distinguished biographical novel. In these chapters, I tried to lay out the general outlines these writers have produced in the production of biographical texts, and how these attempts were a successful step on the road of presenting literary biographies characterized by high world standards. Chapter ten may well seem traditional, but it is important to give a comparative outlook on the views of biography writers themselves when they study and analyse the same character. Among the characters studied ,I selected Bashsliar, Abu Nuwas, Ibn al-Run-i, al-Mutanabbi and al-Maarri. These are outstanding landmarks in the history of Arab verse and the subject of a multitude of studies as well. Modern biographers took these figures as a test field for the deployment and employment of biographical methodologies. I selected these examples to provide comparisons and explain how far these biographies were successful in producing a biography or a profile of those classical poets. The conclusion and the bibliographical list arrived at the end of research. I wish, however, to clarify one important point here. It seems that I could not fix the year 1950 as the temporal parameter of my research but took some textswhich were published shortly beyond that point. The reason for this obvious extension was either to give additional useful details or simply because chapters of such texts had already been published prior to that year and were known to the readership. At times I would satisfy myself with analysing the part rather than the whole. This again was meant to eschew repetition or was due to the fact that the book in question was not available.
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Banville, Scott D. "“A Mere Clerk”: Representing the urban lower-middle-class man in British literature and culture: 1837-1910." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1124222668.
Повний текст джерела
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Kamal, Saadi Moulay Abdelmalek. "Etude en fonction du champ magnétique et de la température d'un gaz quasi-bidimensionnel confiné dans des hétérostructures III-V." Montpellier 2, 1995. http://www.theses.fr/1995MON20158.
Повний текст джерелаАнотація:
Ce travail presente une etude d'un gaz degenere d'electrons quasibidimensionnel confine dans des puits quantiques a modulation de dopage dans une seule barriere (gaalas, galnas, gaas) en presence et en l'absence d'un champ magnetique transverse. Le calcul du profil energetique des puits tenant compte de la non parabolicite et des effets a n-corps a permis la determination des coefficients de transport et des transitions interbandes. Une simple analyse des phenomenes de transport ne permet de dire si les etats qui freinent le niveau de fermi, lorsque celui-ci se trouve entre deux niveaux de landau, sont situes dans le gaz 2d ou a l'exterieur du gaz 2d. Par contre, une analyse minutieuse de l'effet hall quantique et de la dependance avec b de l'energie de luminescence montre qu'il existe une correlation etroite entre ces deux phenomenes: les plateaux de hall correspondent au non linearites de l'energie de luminescence. On montre que sous eclairement et dans les conditions de mesures de l'energie de luminescence et des coefficients de transport, le gaz 2d echange des electrons, lorsque b varie, avec un ou plusieurs reservoirs exterieurs. Cette hypothese permet d'expliquer a la fois les phenomenes de magneto-transport et la dependance avec b de l'energie de photoluminescence
26
Khym, Sungwon. "Magnetotransport studies of semimetallic InAs/GaSb structures." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325145.
Повний текст джерела
27
Garchery, Laurent. "Fabrication et étude des propriétés physiques des nanostructures Si/SiGe : application aux nouveaux dispositifs." Université Joseph Fourier (Grenoble), 1996. http://www.theses.fr/1996GRE10232.
Повний текст джерелаАнотація:
La technologie de la microelectronique silicium beneficie aujourd'hui d'investissements massifs et continus. Tout porte a croire que les excellentes proprietes du systeme si/sio#2 assureront la perennite du si pendant encore de nombreuses annees. Le developpement de nouveaux materiaux pouvant ameliorer les performances des dispositifs a base de si est donc encourage. En particulier, l'heterosysteme si/sige apparait comme le meilleur candidat pour le developpement d'une technologie a heterojonction a base de si. De tels materiaux doivent cependant etre compatibles avec les temperatures de recuit utilisees dans la technologie si. Les deux principaux dispositifs electroniques dans lesquels l'utilisation du sige est envisagee sont le transistor bipolaire et le transistor a effet de champ. Dans le cas du transistor a effet de champ, l'interet du sige est d'ameliorer les proprietes de transport parallele au plan des couches. Cette these est consacree a l'etude experimentale de ces proprietes ainsi qu'a l'analyse et a la comprehension du fonctionnement des heteronjonctions si/sige. Nous rappelons tout d'abord les proprietes de structure de bandes des heterosystemes contraints si/sige ainsi que la methode de mesure par effet hall que nous avons utilisee. Une etude de l'evolution thermique des proprietes de transport et de confinement de modulations de dopage si/sige de type p est ensuite presentee. Puis, nous analysons les proprietes de transport electronique des heterostructures si/sige elaborees sur un pseudo-substrat de sige relaxe. Le principe de fonctionnement specifique des dispositifs mos a canal enterre en sige est ensuite mis en evidence experimentalement. Nous constaterons finalement que les caracteristiques electriques des dispositifs mos a base de si peuvent etre ameliorees par l'introduction d'un canal enterre en sige
28
Guyot, Hervé. "Etude des transitions d'onde de densité de charge et des propriétés de transport des oxydes de molybdène [êta]-Mo4O11 et [gamma]-Mo4O11." Grenoble 1, 1986. http://www.theses.fr/1986GRE10122.
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29
Demouge, Annabelle. "Étude galvanomagnétique de l'alliage semi-métallique Bi-Sb (4 at. % Sb) entre 77 K et 300 K." Vandoeuvre-les-Nancy, INPL, 1996. http://docnum.univ-lorraine.fr/public/INPL_T_1996_DEMOUGE_A.pdf.
Повний текст джерелаАнотація:
Les alliages Bi-Sb sont des matériaux thermoélectriques performants entre 50 K et 250 K, mais leurs propriétés fondamentales sont mal connues, en particulier les concentrations et les mobilités des porteurs, ainsi que la structure de bandes. La présence de deux types de porteurs, électrons et trous, nécessite une étude galvanomagnétique. Nous avons élaboré des lingots de Bi-Sb (4 at. % Sb) par la méthode THM et découpe des échantillons monocristallins et homogènes pour les différentes orientations nécessaires aux mesures des douze coefficients du tenseur galvanomagnétique. Nous avons ensuite réalisé le montage permettant les mesures de magnétorésistivité sous faible champ magnétique entre 77 K et 300 K. Un modèle ellipsoïdal non parabolique à deux bandes et un programme de calcul ont été développés pour permettre d'atteindre les concentrations et les mobilités des porteurs. Les résultats obtenus montrent des concentrations de porteurs dans l'alliage croissant entre 77 K et 300 K de 0,6 10^23m-3 a 6,7 10^23m-3, ce qui traduit une augmentation de l'énergie de recouvrement dans le semi-métal et une énergie de fermi plus faible que dans le bismuth pur. Les valeurs des mobilités des électrons à 77 K sont: #1 220 m2/v. S, #2 < 1 m2/v. S, #3 130 m2/v. S, et pour les trous #1 60 m2/v. S et #3 <1 m2/v. S. L'angle d'inclinaison des ellipsoïdes d'électrons est voisin de 7 quelle que soit la température. Les facteurs de Hall et de magnétorésistance A et M des électrons restent proches de l'unité et montrent une dépendance énergétique modérée du temps de relaxation. Nous donnons enfin les équations permettant de déterminer la structure de bandes de l'alliage semi-métallique Bi#0, 96Sb#0,#0#4 entre 77 K et 300 K
30
Viennot, Jeremie. "Charge and spin dynamics in a hybrid circuit quantum electrodynamics architecture." Phd thesis, Ecole Normale Supérieure de Paris - ENS Paris, 2014. http://tel.archives-ouvertes.fr/tel-01062841.
Повний текст джерелаАнотація:
Cette thèse étudie expérimentalement le mécanisme de couplage entre les degrés de liberté de charge et de spin dans des doubles boîtes quantiques et des cavités supraconductrices de grande finesse. Nous utilisons des nanotubes de carbone comme conducteurs cohérents pour nos boîtes quantiques. Nous avons conçu une expérience et développé de nouvelles méthodes de fabrication afin de pouvoir contrôler ces dispositifs. Avec ces méthodes, nous examinons le couplage résonant entre les transitions électroniques de charge dans les boîtes quantiques et la cavité micro-onde. Nous poussons le système hors équilibre pour caractériser sa dynamique et extraire ses paramètres intrinsèques. Nous étudions la possibilité d'un couplage de photons uniques avec un spin électronique individuel, en utilisant des champs effectifs non colinéaires induits par des interfaces ferromagnétiques comme ingrédient clef pour construire ce couplage. Les résultats préliminaires dans cette architecture en circuit sont prometteurs pour de futures expériences d'électrodynamique quantique en cavité avec des spins uniques.
31
Jean, Bruno. "Propriétés électriques, optiques et électro-optiques du semiconducteur CdIn2 Te4." Bordeaux 1, 1994. http://www.theses.fr/1994BOR10553.
Повний текст джерелаАнотація:
Cette these est consacree aux proprietes electriques, optiques et electro-optiques du semiconducteur ternaire cdin#2te#4. La premiere partie de la these est consacree a l'etude des proprietes optiques et de transport par absorption optique, photoluminescence, photoconductivite et effet hall. La compensation du materiau, due a des defauts antisites dans le sous reseau cationique, a ete mise en evidence par effet hall. Un niveau accepteur situe a environ 40 mev de la bande de valence a ete observe en photoconductivite. D'autre part, l'asymetrie des mesures de conductivite par la methode de van der pauw et aussi des spectres dlts (deep level transient spectroscopy) dont la forme depend de la tension de polarisation ont montre la presence d'un desordre a moyenne distance. Les fluctuations spatiales des bords de bandes qui en resultent permettent d'expliquer la plupart des resultats experimentaux. Enfin, un niveau donneur profond, situe a 0. 5 ev environ sous la bande de conduction, a ete observe par luminescence sur les echantillons presentant un ecart a la stchiometrie important. La seconde partie de ce travail est consacree au reexamen de la mesure du coefficient electro-optique r#4#1 en mode longitudinal. Nous montrons que les classiques mesures en detection synchrone peuvent conduire a des resultats errones si les electrodes transparentes n'ont pas un caractere ohmique. Un modele theorique est ensuite developpe pour rendre compte de la distribution particuliere du champ electrique due au caractere schottky des contacts. Les resultats de diverses mesures en champ electrique continu sont en bon accord avec le modele et nous permettent alors de proposer une nouvelle valeur du coefficient r#4#1, proche de 3pmv##1
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Benarfa, Houria. "Proprietes de photoluminescence de gaas : contribution a l'etude de gaas heteroepitaxie sur (ca,sr)f2 par la technique des jets moleculaires." Toulouse, INSA, 1986. http://www.theses.fr/1986ISAT0019.
Повний текст джерелаАнотація:
ANALYSE DE LA PHOTOLUMINESCENCE DE STRUCTURES GaAs/(Ca,Sr))F2/GaAs, A FLUORURE ACCORDE EN MAILLE AU GAAS; INFLUENCE DES PARAMETRES DE CROISSANCE ET DE LA DISTANCE A L'INTERFACE. COMPARAISON DES PERFORMANCES DE SEMICONDUCTEUR HETEROEPITAXIE A CELLES DE GAAS EPITAXIE; ETUDE DE COUCHES DE GAAS EPITAXIE SUR CAF2 MASSIF
33
Somarakis, Vasileios. "Les relations entre l'Eglise semi-autonome de Crète et l'Etat grec du point de vue nomocanonique." Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00720614.
Повний текст джерелаАнотація:
Le régime de l'Église semi-autonome de Crète est aujourd'hui unique dans l'espace de l'administration des Églises orthodoxes et présente de ce fait des particularités et un intérêt accru. La présente étude relativement au régime de l'Église de Crète évolue autour de deux axes principaux : premièrement autour de l'étude de l'origine et de la formation historiques des relations institutionnelles actuelles entre l'Église de Crète et l'État grec et deuxièmement autour de l'étude et de l'interprétation nomocanonique du cadre institutionnel actuel déterminant et formant l'organisation (centrale et régionale) etle fonctionnement de l'Église semi-autonome de Crète dans l'État grec. L'Église de Crète est aujourd'hui régie par la Loi no 4149/1961 " Sur la Charte statutaire de l'Église orthodoxe en Crète ", dont la rédaction fut considérablement influencée par les textes de la législation statutaire antérieure, tant de l'Église de Crète que de l'Église de Grèce. Ces textes antérieurs avaient introduit un certain nombre d'interventions de l'État dans l'administration ecclésiastique de Crète, dont les effets sont visibles aujourd'hui. L'élaboration et l'adoption d'une nouvelle Charte statutaire pour l'Église de Crète sous la lumière et les conditions de la nouvelle Constitution grecque de 1975 n'ont pas été rendues possibles jusqu'à aujourd'hui. C'est la raison pour laquelle l'objectif et le contenu de la présente étude ont été de présenter l'organisation de l'Église de Crète et toutes les formes de ses rapports avec l'État grec à travers le cadre actuel des garanties constitutionnelles sur la liberté religieuse aussi bien qu'à travers les saints canons de l'Église garantis par la Constitution. La contribution principale de la présente étude réside en l'approche des relations entre l'Église de Crète et l'État grec, non seulement du point de vue législatif et étatique, mais également du point de vue canonique-ecclésiologique, puisque les saints canons constituent le droit interne de l'Église.
34
Banville, Scott Douglass. ""A Mere Clerk" representing the urban lower-middle-class man in British literature and culture : 1837-1910 /." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1124222668.
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Rossi, Dario. "Fracton phases: analytical description and simulations of their thermal behavior." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/23919/.
Повний текст джерелаАнотація:
Many-body physics studies the collective behavior of systems with a large number of microscopic constituents. The interaction between the fundamental particles creates a common behavior within the system with emergent excitations exhibiting uncommon
characteristics. In three spatial dimensions it has recently been found that a new kind of particles can exist characterized by a fractionalized mobility, being either immobile or mobile only along sub-dimensional spaces: fractons.
In this thesis I explore fracton phases focusing on their topological and thermal properties. Fractons can be explained as a generalization of usual topological particles with some fundamental differences, which make fracton order a new field on its own. Fracton models are studied first from the point of view of exactly solvable lattice spin models, focusing on the similarities and differences with usual topological models. Fracton phases are also described through the use of symmetric tensor gauge theory. This gives a theoretical background which is used to explore some possible phases at finite densities of fractons, like Fermi liquids and quantum Hall states.
The thermal properties of such systems are studied in detail through the use of numerical simulations relying on exact-diagonalization. Various correspondences with systems featuring quantum many-body scars are found, in particular with the PXP model. The non-thermal behavior of the models under study is justified by the fragmentation of the Hilbert space in a large number of separated sub-sectors, not related to symmetries of the model. Further, the range of the local Hamiltonian operators is found to be of fundamental relevance in the thermal properties of the system. For certain ranges it is observed that the models are not able to reach the thermal state at long times. Instead, increasing the length of interactions the system becomes ergodic, with the exception of a small number of special eigenstates which remain non-thermal.
36
Thérond, Pierre-Guy. "Etude des propriétés de transport de composés d'actinides." Grenoble 1, 1986. http://www.theses.fr/1986GRE10109.
Повний текст джерелаАнотація:
Mesures de la conductivite electrique, de la magnetoconductivite et de l'effet hall sur echantillons monocristallins de npas::(2) et pusb::(1-x)te::(x); analyse des variations en fonction de la temperature et du champ magnetique, modes de diffusion dominants. Etude de l'effet d'un champ magnetique intense sur la conductivite de uas et up et attribution des variations observees soit a un changement de structure antiferromagnetique soit a l'anisotropie du tenseur de conductivite par rapport au vecteur de modulation de la structure magnetique
37
BHANDARI, CHURNA B. "FIRST-PRINCIPLES STUDY OF ELECTRONIC AND VIBRATIONAL PROPERTIES OF BULK AND MONOLAYER V2O5." Case Western Reserve University School of Graduate Studies / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=case1459296089.
Повний текст джерела
38
Loret, Benjamin. "Problèmes numériques et théoriques de la géomécanique." Paris 6, 1986. http://www.theses.fr/1986PA066239.
Повний текст джерелаАнотація:
Traitement numérique des milieux infinis de la géomécanique: méthodes d'équations intégrales régulières et singulières pour les structures géotechniques en conditions dynamiques; méthode de couplage itérative éléments finis/équations intégrales (applications au demi-espace et demi-plan); vibration d'un pieu fiché dans le demi espace stratifié. Comportement frottant des milieux granulaires: algorithmes locaux d'intégration numérique pour matériaux élastoplastiques type Drucker-Prager; partie élastique déformation des sols; influence de la contrainte moyenne. Problèmes liés à l'anisotropie en grandes transformations (rotations plastiques). Etude de deux types de bifurcation sur les sables; conséquences macroscopiques de la structure granulaire des sables; non-linéarité incrémentale et localisation des déformations.
39
Boujida, Mohamed. "Contribution à l'étude des propriétés de transport de quelques oxydes métalliques et supraconducteurs de basse dimensionnalité." Grenoble 1, 1988. http://www.theses.fr/1988GRE10157.
Повний текст джерелаАнотація:
Les proprietes de transport (magnetoconductivite, effet hall, ondes de densite de charge, ondes de densite de spin, transitions supraconductrices) des oxydes metalliques et supraconducteurs quasi-bidimensionnels sont etudiees a basse temperature
40
Panton, James. "Politics, subjectivity and the public/private distinction : the problematisation of the public/private relationship in political thought after World War II." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:cb636385-aa16-44d1-abf5-2e835e62665c.
Повний текст джерелаАнотація:
A critical investigation of the public/private distinction as it has been conceived in Anglo-American political thinking in the second half of the 20th century. A broadly held consensus has developed amongst many theorists that public/private does not refer to any single determinate distinction or relationship but rather to an often ambiguous range of related but analytically distinct conceptual oppositions. The argument of this thesis is that if we approach public/private in the search for analytic or conceptual clarity then this consensus is correct. Against this I propose that a number of the most dominant invocations of the distinction can be understood to express public/private as an irreducibly political dialectic that mediates the relationship between the subjective and objective side of social and political life. By locating these conceptually diverse invocations within a broader and more determinate framework of the historical development and contestation of the boundaries which establish the conditions for subjectivity, as the assertion of political agency, on the one hand, and which demarcate, police and defend these particular boundaries, as part of the objectively given character of social life and institutional organisation, on the other hand, then a more determinate character to public/private can be recognized. I then seek to explore the capacity of this model to capture and explain the peculiar post-war problematisation of public/private amongst a number of new left thinkers in Britain and America.
41
Young, Cheryl Ann. "A study of the personal literature written in the Eastern Cape in the nineteenth century." Thesis, Rhodes University, 1995. http://hdl.handle.net/10962/d1002274.
Повний текст джерелаАнотація:
The evidence of these diaries, all written in the nineteenth century, reveals the heterogeneous nature of early settler society in the Eastern Cape. Generalizations can only be of the most tenuous kind in such a small sample; but women tend to dwell on the domestic, the men on their public lives, the most reticent about their private lives are the soldiers. There is one diary which can be described as personal; the diarists did not regard their diaries as appropriate repositories of their personal triumphs and failures. The perceptions formed in Britain about the land and people of Africa are not drastically modified upon arrival unless the diarist experiences a prolongued contact with either.
42
Mehera, Asoke Kumar. "Sustainable Value and Shared Value Creation: Case Studies on Australian Banking and Property Organisations." Thesis, 2019. https://vuir.vu.edu.au/40467/.
Повний текст джерелаАнотація:
The stakeholder management framework of the 1980s and the triple bottom line
framework of the 1990s strengthened corporate social responsibility but these
frameworks could not bring about fundamental change in the role of businesses in society
in relation to value creation. Hence, by the beginning of the present century, drawing on
the ‘Sustainable Value’ and ‘Shared Value’ business models, the selected Australian
banking and property organisations are striving to leverage on business strategies for
generation of social and economic values. However, the Australian academic literature
and industry reports demonstrate limited contributions to the sustainable and shared value
literature, and hence, failing to support and deliver a comprehensive business model. To
fill this conceptual and practical gap in the Australian industrial context, this study is
undertaken with a view to recommend an alternative business model to integrate socioenvironmental issues and opportunities into core business strategy.
Research objectives of the underlying study are to: a) explore the adoption of
components of the applied sustainable value and shared value business models by
Australian banking and property organisations for social and economic value creation;
and b) empirically develop an alternative business model for the Australian banking and
property industries based on emerging thematic components from industry-wide
interview responses.
Based on the interpretive paradigm, this study has adopted a qualitative multiple
case study design to conduct semi-structured open-ended face-to-face interviews. The
cases (n=8) in the banking and property industries have been selected through a purposive
critical sampling approach.
A thematic NVivo analysis was conducted based on four thematic components
derived from the applied sustainable and shared value business models, namely clean
technology, sustainability vision at the bottom of the pyramid, reconceiving of
products/services and redefining of the value chain. This study explores how the selected
Australian banking and property organisations are utilising various thematic components
for social and economic value creation in addition to other components (i.e.
customer/stakeholder engagement, community resilience) not otherwise categorically
mentioned within both the above-mentioned models.
The major findings show a number of industry-wide differences, which include a)
banking organisations predominantly leverage sustainability based on product/service
innovation at the bottom of the pyramid level, and b) property organisations predominantly leverage environmental sustainability based on the application of clean
technology through redefining the value chain.
The primary interview data findings suggest that the selected Australian
sustainable and shared value organisations also emphasise the co-creation of value based
on their engagement with customers, stakeholders, and communities. The secondary data
findings suggest that the selected Australian property organisations have ensured a higher
increase in net profit after tax and return on equity compared to the banking organisations.
The secondary data further suggest that organisations (i.e. Suncorp, Charter Hall,
Company X, Stockland) which used the combination of the elements of sustainable and
shared value business models performed better in terms of profitability (i.e. economic
value) than the organisations which only used either the sustainable value (ANZ,
Lendlease) or the shared value (Bendigo, NAB) model. The only exception being
Stockland, which experienced a slight decrease in the return on equity during the 2014-
18 period inspite of almost triple digit increase in net profit during the above-mentioned
period. In terms of social value, the secondary data further suggest that the selected
banking and property organisations have undertaken quite considerable social and
community investments while leveraging on the components of various business models.
The main recommendation of this study is an empirically developed alternative
business model for value co-creation based on two new thematic components, which are
customer/stakeholder engagement and community resilience that emerged from the
industry case interviews. The significance of the study lies in the fact that all future
academic researchers and practice managers should be able to implement the
recommended business model for value co-creation to enhance social and economic
value. One of the other major implications of the study lies in its application of a
stakeholder-centric (i.e. customers, communities) value creation model by Australian
banking organisations which have recently gone through the Financial Services Royal
Commission investigation. The future theoretical implications of this study on value cocreation can be considered in terms of a better understanding of stakeholder theory
(encompassing customers and communities) and agency theory (encompassing valueseeking organisational agents) with respect to the banking and property industry in
Australian context.
43
陳明義. "A Novel Control Strategy for Multi-Phase Battery Chargers without Hall Current Sensors." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/68424618990726185360.
Повний текст джерелаАнотація:
碩士明新科技大學
電機工程研究所
98
Generally, one should use one large input capacitor rated from thousands of micro farads to ten-thousands of micro farads when applying Reflex method for battery charger. However, it is very expensive to have this kind of large capacitors. This paper proposes a novel control strategy with separate charging time to reduce the loading of the input capacitor, so that one may use a smaller input capacitor, and then reduce the cost. In addition, a current detection scheme is also proposed by using a difference amplifier followed by a low pass filter instead of the Hall-effect current sensor for each phase current sensing, so that the implementation cost can be greatly reduced. Simulation and experimental results are shown to verify the proposed charging scheme.
44
Yang, Da-Wei, and 楊大為. "Design and Implementation of LLC-type Half-Bridge Converter for Contactless Battery Charger." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/91529629641837341692.
Повний текст джерелаАнотація:
碩士中原大學
電機工程研究所
98
To charge electronic products, a conduct-type charging by means of metal contact connections is mostly adopted in traditional chargers. However, both the contact points and the exposure of the charger connector cause the vulnerability as well as the corrosion of metal. In certain environments, the use of conduct-type charging has become pretty dangerous. In regard to safety concerns, the non-contact inductive charging technology has therefore arisen. To keep pace with the cutting-edge technology, this thesis will probe into the application of the non-contact inductive power charging technology. In this thesis, a half-bridge inverter is employed. The transformer magnetizing inductance as well as the leakage inductance is used to carry out resonance. The switch with zero voltage switching (ZVS) achieves the goals of reducing the stresses of components, the losses in switching , and the electromagnetic interference. Furthermore, the use of resonant circuit enhance the overall efficiency. A 90W non-contact charger with DC 270V input and 12V output voltage, is implemented in this thesis. In a full loaded condition, while an air gap is 0.15mm, the system efficiency is 75.42%. The system efficiency is 60.17% at the maximum air gap of 0.75mm.
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Pan, Ping-Lung, and 潘屏榮. "A Single-Stage Asymmetrical Half-Bridge Rapid Charger with Energy Recovery for Electric Vehicle." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/17826281887994284431.
Повний текст джерелаАнотація:
碩士義守大學
電子工程學系
91
A Single-Stage Asymmetrical Half-Bridge Rapid Charger with Energy Recovery for Electric Vehicle * Ping-Lung Pan * * Huang-Jen Chiu * * Sun-Lon Jen Department of Electronic Engineering I-Shou University, Taiwan ROC Abstract Electric Vehicle posses some advantages such as lower noise and less pollution. Moreover with batteries required long charging time as main power source can cause a practical bottleneck. The conventional rapid charger has the disadvantage of shortening lifetime of batteries. In this thesis, a novel rapid charger with energy recovery scheme is proposed. The main power switches can be eliminated due to the proposed single stage power converter topology. Furthermore zero-voltage-switching (ZVS) capability of the adopted asymmetrical half-bridge topology enhances the power density of the charger. The energy recovery cell stores the negative pulse energy into DC bus capacitor temporarily to avoid unnecessarily energy consumption in conventional schemes. In thesis a prototype module is implemented. Some experiments are shown to verify the feasibility of the proposed scheme. Keywords：Rapid charger，Single Stage Asymmetrical Half-Bridge * The author ** The advisor
46
WU, RUI-GIN, and 吳瑞欽. "The simulation and optimal output filter design of the half-controlled bridge converters as battery charger." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/27988467849794410660.
Повний текст джерела
47
Papadimitriou, Georgios. "Radii and neutron correlations of (6,8)He within the Gamow Shell Model." 2011. http://trace.tennessee.edu/utk_graddiss/1213.
Повний текст джерелаАнотація:
We study the spatial correlations between halo neutrons in 6,8He within the complex-energy Gamow Shell Model (GSM). To this end, we calculate the neutron and proton radii, and two-neutron correlations in a large shell model space consisting of the 0p3/2 resonance and non-resonant p-sd scattering continuum. We use schematic forces and the finite-range Modified Minnesota interaction.The calculated charge radii, corrected for the core polarization and spin-orbit effects, are compared to the values extracted from measured atomic isotope shifts.We find that the charge radius of 6He primarily depends on the two-neutron separation energy and the shell-model occupation of the 0p3/2 orbit.We confirm that the ground-state GSM wave function of 6Heis dominated by the S=0 component representing a di-neutron structure. On the other hand, the correlation density of the 2+ resonance in 6He indicates a very weak di-neutron correlations in this state. We study the effect of pairing correlations on the neutron and charge radii of 6He and we confirm the presence of the Pairing-Anti-Halo effect in this light system.Finally, we calculate the charge radius of 8He in the full GSM space with the help of the Density Matrix Renormalization Group (DMRG) technique. The results of our realistic GSM+DMRG studies presented in this work show promise for extending the reach of the realistic complex-energy shell model to heavier halo systems.
48
Arora, Himani. "Charge transport in two-dimensional materials and their electronic applications." 2020. https://tud.qucosa.de/id/qucosa%3A74071.
Повний текст джерелаАнотація:
Semiconducting two-dimensional (2D) materials have gained considerable attention in recent years owing to their potential in future electronics. On the one hand, the conventional 2D semiconductors, such as transition metal dichalcogenides (TMDCs (MoS2, WS2, etc.) are being exhaustively studied, on the other hand, search for novel 2D materials is at a rapid pace. In this thesis, we explore 2D materials beyond graphene and TMDCs in terms of their intrinsic electronic properties and underlying charge transport mechanisms. We introduce 2D semiconducting materials of indium selenide (InSe) and gallium selenide (GaSe), and a novel π-d conjugated Fe3(THT)2(NH4)3 metal-organic framework (MOF) as potential candidates for their use as active elements in (opto)electronic applications.
Owing to the air-sensitivity of InSe and GaSe, their integration into active devices has been severely constrained. Here, we report a hexagonal boron nitride (hBN) based encapsulation, where 2D layers of InSe and GaSe are sandwiched between two layers of hBN; top hBN passivating the 2D layer from the environment and bottom hBN acting as a spacer and suppressing charge transfer to the 2D layer from the SiO2 substrate. To fabricate the devices from fully encapsulated InSe and GaSe layers, we employ the technique of lithography-free via-contacts, which are metal contacts embedded within hBN flakes. Based on our results, we find that full hBN encapsulation preserves InSe in its pristine form and suppresses its degradation with time. Consequently, the electronic properties of encapsulated InSe devices are significantly improved, leading to a mobility of 30–120 cm2 V−1 s−1 as compared to a mere ∼1 cm2 V−1 s−1 obtained for unencapsulated devices. In addition, encapsulated InSe devices are stable for a prolonged period of time, overcoming their limitation to be air-sensitive. On employing full hBN encapsulation to GaSe, a high photoresponsivity of 84.2 A W−1 at 405 nm is obtained. The full hBN encapsulation technique passivates the air-sensitive layers from various degrading factors and preserves their unaltered properties. In the future, this technique can be applied to other 2D materials that have been restricted so far in their fundamental study and applications due to their environmental sensitivity.
MOFs are another emerging class of semiconducting 2D materials investigated in this thesis. They are hybrid materials that consist of metal ions connected with organic ligands via coordination bonds. In recent years, advances in synthetic approaches have led to the development of electrically conductive MOFs as a new generation of electronic materials. However, to date, poor mobilities and hopping-type charge transport dominant in these materials have prevented them from being considered for electronic applications. In this work, we investigate a newly developed π-d conjugated Fe3(THT)2(NH4)3 (THT: 2,3,6,7,10,11-hexathioltriphenylene) MOF. The MOF films are characterized with a direct bandgap lying in the infrared (IR) region. By employing Hall-effect measurements, we demonstrate band-like transport and a record-high mobility of 230 cm2 V−1 s−1 in Fe3(THT)2(NH4)3 MOF films. The temperature-dependent conductivity confirms a thermally activated charge carrier population in the samples induced by the small bandgap of the analyzed MOFs.
Following these results, we demonstrate the feasibility of using this high-mobility semiconducting MOF as an active material in thin-film optoelectronic devices. The MOF photodetectors fabricated in this work are capable of detecting wavelengths from UV to NIR (400–1575 nm). The narrow IR bandgap of the active layer constrains the performance of the photodetector at room temperature by band-to-band thermal excitation of the charge carriers. At 77 K, the device performance is significantly improved; two orders of magnitude higher voltage responsivity, lower noise equivalent power, and higher specific detectivity of 7 × 10^8 cm Hz1/2 W−1 are achieved at 785 nm excitation, which is a direct consequence of suppressing the thermal generation of charge carriers across the bandgap. These figures of merit are retained over the analyzed spectral region (400–1575 nm) and are comparable to those obtained with the first demonstrations of graphene and black phosphorus based photodetectors, thus, revealing a promising application of MOFs in optoelectronics.Zweidimensionale (2D) Halbleiter haben dank ihres Potenzials für elektronische Anwendungen in den letzten Jahren große Aufmerksamkeit erregt. Dabei werden einerseits konventionelle 2D-Materialien, wie die Übergangsmetall-Chalkogenide (TMDCs) (MoS2, WS2, usw.) intensiv erforscht. Andererseits schreitet auch die Suche nach neuen 2D-Materialien rasch voran. Diese Dissertation stellt Forschungsergebnisse zu elektrischen Eigenschaften und den zugrundeliegenden Ladungstransportmechanismen von 2D-Materialien jenseits von Graphen und TMDCs vor. Untersucht wurden die 2D-Halbleiter Indiumselenid (InSe) und Galliumselenid (GaSe), sowie eine neuartige π-d konjugierte Metallorganische Gerüstverbindung (Metal-Organic Framework, MOF) Fe3(THT)2(NH4)3. Diese Materialien sind vielversprechende Kandidaten für elektronische und optoelektronische Anwendungen. InSe und GaSe sind besonders luftempfindliche Materialien. Aus diesem Grund ist ihre Verwendung für aktive Bauteile trotz ihrer hervorragenden elektrischen Eigenschaften bis heute sehr begrenzt. In dieser Arbeit wird ein effektives Verkapselungsverfahren vorstellt, bei dem InSe- oder GaSe-2D-Schichten zwischen zwei Schichten aus hexagonalem Bornitrid (hBN) eingebettet werden. Die untere Schicht hBN isoliert das Material vom Substrat Siliziumdioxid (SiO2), während die obere Schicht das 2D-Material luftdicht isoliert. Um Bauteile aus komplett eingekapseltem InSe oder GaSe herzustellen, wurden lithographiefreie, sogenannte via-Kontakte hergestellt. Dies sind Metallkontakte, die bereits vor der Verkapselung in die hBN-Schichten integriert werden. Die hBN-Verkapselung erhält InSe in seiner ursprünglichen Form. Die hier vorgestellten Ergebnisse zeigen, dass sich die elektronischen Eigenschaften von InSe durch Verkapselung signifikant verbessern, was zu elektrischen Mobilitäten von 30–120 cm2 V−1 s−1 gegenüber nur rund ∼1 cm2 V−1 s−1 in unverkapselten Bauteilen führt. Darüber hinaus bleiben die Eigenschaften der verkapselten InSe-Bauteile über einen langen Zeitraum erhalten und degradieren nicht mehr bei Kontakt mit Luft. Die Verkapselung von GaSe ermöglicht den Einsatz in Fotodetektoren, bei einer Wellenlänge von 405 nm wird eine Fotoempfindlichkeit von 84.2 A W−1 gemessen; auch hier bewahrt die Verkapselung die empfindlichen Schichten vor schädlichen Einflüssen und konserviert so ihre unveränderten Eigenschaften. In der Zukunft kann diese Technik auch für andere 2D-Materialien eingesetzt werden, insbesondere für solche, deren Erforschung und Anwendung durch die große Empfindlichkeit bis heute eingeschränkt ist. Darüber hinaus untersucht diese Dissertation mit Metallorganischen Gerüstverbindungen (MOFs) eine zweite Klasse halbleitender 2D-Materialien. MOFs sind hybride Materialien aus Metallionen, die mit organischen Molekülen als Verbindungselementen eine meist kristalline Struktur bilden. In den letzten Jahren haben Fortschritte in der synthetischen Herstellung zur Entwicklung von elektronisch leitfähigen MOFs geführt. Die niedrige Mobilität und der sogenannte hopping-Ladungstransport der gängigsten MOFs haben jedoch verhindert, dass diese für Anwendungen betrachtet wurden. In dieser Arbeit wird eine kürzlich neu entwickelte, π-d-konjugierte Fe3(THT)2(NH4)3 (THT: 2,3,6,7,10,11-hexathioltriphenylene) MOF vorgestellt. Der MOF Film hat eine direkte Bandlücke im Infrarot(IR)-Bereich liegend. Mithilfe von Hall-Effekt-Messungen wurde gezeigt, dass der Transport in den Fe3(THT)2(NH4)3 MOF Filmen mit dem Drude-Modell konsistent ist. Darüber hinaus wird eine bis jetzt nicht übertroffene Mobilität von 230 cm2 V−1 s−1 gemessen. Die Temperaturabhängigkeit der Leitfähigkeit bestätigt, dass die kleine Bandlücke zu thermisch aktivierten Ladungstragerdichten in den Proben führt. Auf Grundlage dieser Ergebnisse wird die Machbarkeit von hochmobilen halbleitenden Fe3(THT)2(NH4)3 MOFs als aktives Material in dünnen optoelektronischen Bauteilen gezeigt. Die hier vorgestellten MOF Fotodetektoren reagieren auf Wellenlängen im UV bis Nahinfrarotspektrum (400–1575 nm). Die schmale Bandlücke schränkt die Leistung des Fotodetektors bei Raumtemperatur durch thermische Band-zu-Band-Anregung der Ladungsträger ein. Bei einer Temperatur von 77 K verbessert sich die Leistung des Detektors signifikant: Bei 785 nm wird eine um zwei Größenordnungen erhöhte Spannungsempfindlichkeit, eine niedrigere äquivalente Rauschleistung sowie eine höhere spezifische Empfindlichkeit von 7 × 10^8 cm Hz1/2 W−1 erhalten. Dies ist eine direkte Konsequenz der Unterdrückung thermischer Anregung von Ladungsträgern über die Bandlücke. Diese Leistungszahlen sind über das analysierte Spektrum (400–1575 nm) gültig und vergleichbar mit den ersten Fotodetektoren auf Grundlage von Graphen und Schwarzem Phosphor. Die Ergebnisse zeigen deutlich das Potenzial von MOFs für optoelektronische Anwendungen.
49
z, Drozdowa Byszewski Marcin. "Propriétés optiques d'un gaz d'électrons bidimensionnel soumis à un champ magnétique." Phd thesis, 2005. http://tel.archives-ouvertes.fr/tel-00010691.
Повний текст джерелаАнотація:
Les propriétés d'un gaz électronique bidimensionnel soumis à champs magnétiques intenses et à bas champs magnétiques sont étudiés par la spectroscopie optique: l'effet Hall quantique fractionnaire (FQHE) par photoluminescence et diffusion inélastique de la lumière, puis un nouvel effet oscillatoire de la résistance induit par micro-ondes (MIROs) par transport et absorption des micro-ondes. Les effets des interactions entre électrons du 2DEG sont à l'origine de FQHE. Jusqu'à maintenant, les expériences d'optiques n'ont pas permis les études des interactions entre électrons sur toute la gamme de fractions. Les fractions 1/3, 2/5, 3/7, 3/5, 2/3 et 1 sont clairement observées dans les spectres non traités et montrent une symétrie autour du facteur de remplissage 1/2. La symétrie des fermions composites ets observée dans les spectres. A bas champ magnétique, sous irradiation micro-onde, les propriétés de transport s'écartent nettement des oscillations bien connues de Shubnikov - de Haas pour évoluer vers une série d'états de résistance zéro. Les résultats des mesures d'absorption des micro-ondes sont présentés pour deux échantillons. L'échantillon de basse mobilité montre seulement une absorption autour de la résonance cyclotron (CR). L' échantillon de haute mobilité montre aussi des signaux d'absorption aux harmoniques de la CR. Les mesures ont permis d'inférer l'existence de deux processus d'absorption différents et séparés. L'absorption non résonante est mieux visible en transport et observée comme MIROs, et l'absorption résonante, mieux observée dans les mesures d'absorption, suit probablement les règles de polarisation de résonance cyclotron.
50
Vicherková, Veronika. "Novodobá česká mozaika jako specifický druh umění v architektuře 2. poloviny 20. století." Master's thesis, 2014. http://www.nusl.cz/ntk/nusl-340044.
Повний текст джерелаАнотація:
(in English): Present thesis is foucused on mosaic art as a prticular type of art in architecture, shows the specifical means of expression in mosaic art. It describes the political and sociological conditions of connection of architecture with applied art in Czechoslovakia in 2nd half of 20th century. It follows the history and development of mosaic art in first and in second half of 20th. century and represents the main authors and projects. It points the problematic todays reflection of public art of communistic era in Czechoslovakia. The thesis brings a selected image- catalogue and comprehensive written inventory of traced projects.