Une première partie de cette thèse est méthodologique: elle vise à améliorer la thermochronométrie (U-Th-Sm)/He sur apatite et les modèles de diffusion actuels. Nous avons étudié le cas du Massif Armoricain (France), et celui des Alpes Suisses. Nos travaux montrent que la rétentivité en hélium des apatites est plus élevée que prévu par les modèles traditionnellement utilisés. Une approche statistique comprenant des algorithmes d'apprentissage montre que la composition chimique des grains ne semble pas jouer sur la rétentivité des apatites en hélium. Le principal paramètre contrôlant la dispersion des âges hélium est l'état d'endommagement des cristaux. Nous proposons une approche de physique/minéralogie expérimentale pour le caractériser à l'échelle nanométrique. Dans la dernière partie de la thèse, nous avons appliqué la méthode (U-Th-Sm)/He sur apatite au cas de la marge algérienne. Nous mettons en évidence une phase majeure de dénudation dans la région des Petites Kabylies au cours du Tortonien. Cette phase marque probablement le début de l'inversion de la marge, bien plus précocement que suggéré jusqu'alors. / The first part of the thesis aims at improving the methodology and the models involved in apatite (U-Th-Sm)/He thermochronology. For this purpose, we studied two geological cases: the Armorican Massif (France) and the Swiss Alps. Our work suggests that apatite helium retentivity is higher than predicted in traditional models. A statistical approach using machine learning algorithms evidences that the apatite chemical composition of grains does not influence helium retentivity. The key parameter is the parent radionuclide and the crystal damage contents. We suggest an experimental procedure in order to characterize damage in apatite at the sub-micrometer scale. In the last part of the thesis, we applied the (U-Th-Sm)/He method to the Algerian Margin. We evidenced a major denudation phase in Petite Kabylie ("Lesser Kabylia") during the Tortonian times. This phase likely corresponds to the initiation of the margin inversion, earlier than previously suggested.

Dans cette thèse de doctorat, des simulations numériques basées sur un modèle fluide 2D sont utilisées pour caractériser des jets de plasma d’Hélium pulsés. Le modèle pour les jets de plasma d’Hélium est développé pour décrire des jets qui s’écoulent dans des atmosphères de N2 et O2 et interagissent avec des cibles. La dynamique de la décharge dans les jets d’Hélium impactant une cible métallique à la masse est analysée pour des polarités positive et négative de la tension appliquée. Les évolutions temporelles et spatiales de champ électrique associées au premier front d’ionisation et au front de rebond sont en bon accord qualitatif avec des mesures récentes de champ électrique. Puis, l’interaction plasma cible entre une décharge positive et une cible diélectrique en BSO est examinée en détail et les résultats sont directement comparés aux expériences. Un bon accord est obtenu entre les simulations et les expériences sur les évolutions temporelles et spatiales de champ électrique. Des valeurs maximales de champ électrique dans la cible de 5 kV.cm−1 ont été obtenues expérimentalement et numériquement. Le champ électrique dans le plasma de l’ordre de quelques dizaines de kV.cm−1 est fortement diminué par le changement de permittivité de la cible. Le champ électrique dans la cible est presque exclusivement dû aux fortes valeurs de charges de surface déposées sur la surface de la cible. Finalement, l’influence des évolutions de champ électrique sur la production d’espèces actives près des cibles est évaluée. On démontre qu’avec des cibles métalliques la synergie entre le premier front et le front de rebond augmente la production d’espèces près de la cible. / In this PhD thesis numerical simulations based on a 2D fluid model are used to characterize pulsed Helium plasma jets. The model for He plasma jets is developed to describe He jets flowing in N2 and O2 atmospheres and interacting with targets. The discharge dynamics in He jets impacting a grounded metallic target is analyzed with both positive and negative polarities of applied voltage. The temporal and spatial evolutions of electric field associated to the first and rebound ionization fronts are in good qualitative agreement with recent electric field measurements. Then, the plasma-target interaction occurring between a positive discharge and a BSO dielectric target is investigated in detail and results are directly compared with experiments. A good agreement is obtained between simulations and experiments concerning the temporal and spatial profiles of electric field. Maximum values of electric field inside the target of 5 kV.cm−1 are found. The high electric field in the plasma of the order of dozens of kV.cm−1 is severely depleted by the change of permittivity. As a result, the electric field experienced inside the target is almost exclusively originated by the high values of surface charge deposited on the target surface. Finally, the influence of the electric field evolutions on the production of chemically active species close to the targets is evaluated. It is shown that with metallic targets the synergy between the first and rebound fronts increases species production close to the target.

Recently Wulfman found great merit in Barut's idea on atomic super-multiplets, and he introduced the concept of the generalized Hamiltonian that is the Hamiltonian of all atoms. 24 Investigating the Schrodinger equation with this generalized Hamiltonian, it should be possible to relate the properties of different atoms and find the structure of the periodic chart from fundamental principles of dynamics and group theory. One can can use the same kinds of methods for relating the properties of different states of a single hydrogen atom with the aid of the degeneracy group S0 (4) and dynamical group SO (4, 2). These groups represent the symmetries of the time-independent and time-dependent Schrodinger equations with ordinary Hamiltonian.(25,26) The idea then is to apply these methods to the system defined by a generalized Hamiltonian. In chapter II of this thesis, we will consider the classification of chemical elements, in the light of the concept of the generalized Hamiltonian. We will make a group theoretical classification based on the characteristics of the outermost electrons in the central-field model of atomic ground states. We conclude that the classification group may be SO (p,q) with p+q≧, p ≧4. In chapter III of this thesis, we will review Wulfman's work briefly and consider an application of his idea to the ground state of helium making use of the group SO (4,1) xSO (4,1). We arrive at the conclusion that we can obtain physically significant configuration mixing using SO (4,1) xSO (4,1) or SO (4,2) xSO (4,2) in a manner analogous to the way in which SO (4) xSO (4) is used to determine configuration mixing in doubly excited states of helium-like systems.

The properties of a physical system are determined by its equation of motion, and every such equation admits one-parameter groups which keep the equation invariant. Thus, for a particular system, if one can find the generator of a one-parameter group which keeps the equation and some further function or functional invariant, then one can change this system into others by changing the parameter, while keeping some properties constant. In this way, one can tell why different systems have some common properties. More importantly, one can use this method to find relationships between the physical properties of different systems. In the next section, we will illustrate the group theoretic approach by applying it to systems of two coupled oscillators and the hydrogen molecular ion. In section III of this thesis, we will investigate the helium atom system, considering both classical and quantum cases. In the quantum case our attention will be concentrated on the Schrodinger equation in matrix form. We will use a finite set of wavefunctions as our basis. Hence the results obtained will be approximate.

京都大学 / 0048 / 新制・論文博士 / 博士(理学) / 乙第13217号 / 論理博第1562号 / 新制||理||1638(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 永江 知文, 教授 鶴 剛, 准教授 成木 恵 / 学位規則第4条第2項該当 / Doctor of Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21756号 / 工博第4573号 / 新制||工||1713(附属図書館) / 京都大学大学院工学研究科機械理工学専攻 / (主査)教授 蓮尾 昌裕, 教授 木村 健二, 教授 江利口 浩二 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Denna studie är en kvalitativ studie med metodansatsen textanalys. Intentionen är att undersöka hur köns- och genusframställningar kommuniceras i nutida populära barnlitterära verk för yngre elever. Studien diskuterar hur implicita och explicita budskap förmedlas i barnlitteratur, genom att undersöka skönlitteratursmaterialets didaktiska potential i värdegrundsarbetet för Läroplan för grundskolan, förskoleklassen och fritidshemmet (Skolverket 2022). Studiens syfte uppnås genom en kritisk diskursanalys med fokus på huvudkaraktärerna och några utvalda bikaraktärer med ett kön- och genusperspektiv. Det teoretiska ramverket i studien består av flera olika diskursanalytiska perspektiv. Den analysmetod som har tillämpats vid analys av textmaterialet är Faircloughs tredimensionella modell. Studien inkluderar även en bildanalys för att undersöka bildernas kommunikation och en multimodal analys för att granska samspelet mellan text och bild. Bildanalysresultatet visar att en konventionell tolkning kan göras om karaktärernas könstillhörighet genom att granska karaktärernas kroppsfärger, ögon och om karaktären har eller inte har ögonfransar. I resultatet framkommer det att kvinnliga respektive manliga könsnormer och könsmönster förmedlas i materialet.

Nonlinear dispersive partial differential equations occur in a variety of areas within mathematical physics and engineering. We study several classes of such equations, including scalar complex partial differential equations, vector partial differential equations, and finally non-local integro-differential equations. For physically interesting families of these equations, we demonstrate the existence (and, when possible, stability) of specific solutions which are relevant for applications. While multiple application areas are considered, the primary application that runs through the work would be the nonlinear dynamics of vortex filaments under a variety of physical models. For instance, we are able to determine the structure and time evolution of several physical solutions, including the planar, helical, self-similar and soliton vortex filament solutions in a quantum fluid. Properties of such solutions are determined analytically and numerically through a variety of approaches. Starting with complex scalar equations (often useful for studying two-dimensional motion), we progress through more complicated models involving vector partial differential equations and non-local equations (which permit motion in three dimensions). In many of the examples considered, the qualitative analytical results are used to verify behaviors previously observed only numerically or experimentally.

A variant of RABBITT pump-probe spectroscopy in which the attosecond pulse train comprises both even and odd harmonics of the fundamental IR probe frequency is explored to measure time-resolved photoelectron emission in systems that exhibit autoionizing states. It is shown that the group delay of both one-photon and two-photon resonant transitions is directly encoded in the energy-resolved photoelectron anisotropy as a function of the pump-probe time-delay. This principle is illustrated for a 1D model with symmetric zero-range potentials that supports both bound states and shape-resonances. The model is studied using both perturbation theory and solving the time-dependent Schodinger equation on a grid. Moreover, we study the case of a realistic atomic system, helium. In both cases, we demonstrate faithful reconstruction of the phase information for resonant photoemission.

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