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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
521

Resolution de l'equation de transport et applications dans le plasma ionospherique

Lilensten, Jean 02 June 1989 (has links) (PDF)
On trouve dans l'ionosphère des hautes latitudes deux sources majeures d'ionisation : les électrons créés par photo-ionisation solaire, et les électrons précipités. L'établissement de l'équation de transport, qui décrit leur évolution est rappelé, puis nous en discutons et testons un modèle de résolution. Utilisant ce programme, nous calculons la production secondaire diurne d'électrons pour divers flux solaires, et nous en proposons un modèle mathématique plus simple. Puis nous étudions le bilan énergétique des électrons thermiques, à partir de précipitations d'électrons. L'équation du bilan détermine la balance entre les termes de chauffage, de relaxation, et de conduction de la chaleur. Nous montrons, en utilisant des mesures de façon intensive (radar EISCAT, satellite VIKING), que dans l'état actuel des connaissances des sections efficaces, ce bilan est vérifié. L'effet des précipitations d'ions est mis en évidence lors d'une des orbites du satellite.
522

Transport des protons dans l'ionosphère aurorale

Galand, Marina 07 November 1996 (has links) (PDF)
Les électrons et les protons suprathermiques, issus du soleil et précipitant dans l'atmosphère des hautes latitudes, constituent une source d'énergie de l'ionosphère terrestre. Ces particules interagissent avec le gaz thermique ambiant par collisions. L'équation de Boltzmann, fournissant les flux de particules en altitude, énergie et angle d'attaque, permet une description des plus complètes du transport de ces particules. Nous la redémontrons dans le cas dissipatif, le plus général, et nous proposons une résolution originale des équations de transport des protons et des atomes d 'hydrogène, équations couplées via les réactions de changement de charge. Cette résolution, fondée sur l'introduction de forces dissipatives pour décrire la dégradation énergétique des particules précipitant, permet la prise en compte des redistributions angulaires, d'origine collisionnelle ou magnétique, jusqu'alors négligées. Pourtant, leur effet a été observé, depuis le sol, sur les émissions des atomes d 'hydrogène, comme en témoigne la composante, décalée vers le rouge, du profil Doppler selon le zénith magnétique. La résolution adoptée ici est validée par comparaison avec un autre modèle, dans le cas classique sans redistribution angulaire. L'influence de l'effet de miroir magnétique est discutée: cet effet ne semble pas pouvoir expliquer, à lui seul, le décalage vers le rouge observé. La redistribution angulaire collisionnelle doit jouer un rôle significatif. Enfin, une comparaison de notre modèle avec les données de la fusée Proton 1 est proposée.
523

Theoretical studies of slow collisions : elastic electron scattering from positive ions, charge transfer in one-electron ion-ion systems and mutual neutralization of H⁻/D⁻ and H⁺₂

Shepherd, Juliet January 2001 (has links)
No description available.
524

Liouville's equation and radiative acceleration in general relativity

Keane, Aidan J. January 1999 (has links)
No description available.
525

The study of e'+e'-#->##mu#'+#mu#'-(#gamma#) and the measurement of trilinear gauge couplings at LEP2 using the DELPHI detector

Libby, James Frederick January 1999 (has links)
No description available.
526

Angular momentum polarisation effects in inelastic scattering

Chadwick, Helen J. January 2012 (has links)
In this thesis, a joint experimental and theoretical investigation of the vector properties that describe the inelastic scattering of a diatomic radical with an atomic collision partner is presented. A particular emphasis is placed on those correlations that include the final rotational angular momentum, j', of the radical. The depolarisation of both NO(A) and OH(A) brought about through collisions with krypton has been studied, providing a measure of the j-j' correlation, where j is the initial rotational angular momentum associated with the diatom. The total depolarisation cross- sections for both collisional disorientation and disalignment have been measured using quantum beat spectroscopy, and modelled theoretically using quasi-classical trajectory (QCT) calculations. The agreement between experiment and theory for NO(A)-Kr is excellent, but is not observed for OH(A)-Kr under thermal conditions. This has been attributed to the importance of electronic quenching in OH(A)-Kr. The depolarisation cross-sections have also been determined at a higher collision energy for OH(A)-Kr where electronic quenching is less significant, and the experimental results are in better agreement with those obtained theoretically. The NO(A)-Kr depolarisation cross-sections fall with increasing rotational quantum number, N, whereas for OH(A)-Kr, they exhibit less of an N dependence. This trend is mirrored in the elastic depolarisation cross-sections, which have also been determined experimentally for OH(A)-Kr. The significantly attractive and anisotropic nature of the OH(A)-Kr potential energy surface (PES) accounts for these observations. The j-j' correlation is extended to include the initial (relative) velocity (k) in a new theoretical treatment of the k-j-j' correlation. The formalism developed is used with the results from the QCT calculations for NO(A)-Kr and OH(A)-Kr to provide further insight into the mechanism of depolarisation in the two systems. Collisions of NO(A) with krypton do not cause significant depolarisation due to their impulsive nature, and the projection of j onto the kinematic apse is conserved. In contrast, collisions of OH(A) with krypton effectively randomise the direction of j, again showing the influence of the anisotropic and attractive nature of the PES. However, the projection of j onto the kinematic apse is still conserved. The inelastic scattering of NO(X) with argon and krypton has also been investigated, using a crossed molecular beam apparatus. The initial Λ-doublet state of the NO(X) was selected using hexapole focussing, and the products of the collision detected using velocity mapped ion imaging. The state to state differential cross-sections (equivalent to the k-k' correlation, where k' is the final relative velocity) have been measured for collisions which conserve the initial spin-orbit level of the NO(X) with krypton. The same parity dependent effects were seen as have been observed previously for NO(X)-Ar. The collision induced alignment (equivalent to the k-k'-j' correlation) of NO(X) as a result of scattering with argon has also been determined experimentally. The results can be explained classically by considering the conservation of the projection of j onto the kinematic apse.
527

Možnosti speciálně pedagogické diagnostiky u dětí s kombinovaným postižením / Possibilities of special educational diagnostis for children with multiple disabilities

Budišová, Eva January 2011 (has links)
This diploma thesis deals with a view to the special pedagogical diagnostic issue accordance to the children with multiple disabilities. By these children whose disability is mostly the hardest character is making special pedagogical diagnostic as much as correct and accurate very difficult. This diagnostic is very important for developing an individual plan of a special pedagogical intervention. The work is focused on both the individual areas of special pedagogical diagnostic and the complex diagnostic tools. In these areas are mentioned the methods and the materials of a foreign literature which is possible to use with a group of children with multiple disabilities. In the second part of the thesis are developed the results of a survey which brings a practical look to this issue. All these collected knowledge and experience should have become the benefit which should have been a starting point for searching other partial methods. These methods are dealing, for now, with still newly making issue of special pedagogical diagnostics of children with multiple disabilities.
528

Mesure de la production W+W− dans les collisions proton-proton à p s = 7 TeV avec le détecteur ATLAS au LHC / Measurement of W+W− production in Proton-Proton Collisions at p s = 7 TeV with the ATLAS Detector at the LHC

Li, Shu 02 November 2012 (has links)
Cette thèse présente le mesure des sections efficaces de production WW MS et la détermination des couplages triples (TGCs) correspondants en utilisant ces 4.7 ${rm fb}^{-1}$ de donnes 2011 de collision $pp$. Ces mesures permettent un test contraignant du secteur 'électrofaible non abélien $SU(2) times U(1)$ du Modèle Standard; donnent l'opportunité de sonder la nouvelle physique `a travers les couplages triples anormaux de bosons de jauge (aTGCs) qui seront observés dans la distribution des variables cinématiques des WW produits ou de leurs produits de désintégration finaux dans le secteur de haute 'énergie; et permettent d'avoir une bonne compréhension du bruit de fond irréductible dans la recherche du boson de Higgs dans le canal de d'esint'egration $H rightarrow W^{+}W^{-}$.Ce travail de th`ese donne un base solide pour les mesures `a venir de la production WW avec les $sim$25 ${rm fb}^{-1}$ de luminosité intègré de donnes a 8 TeV prévue pour la fin 2012, qui conduiront vers une amélioration de la précision et des limites plus strictes sur les aTGCs. / This thesis presents a measurement of the SM WW production cross section and the determination of the corresponding limits on anomalous triple gauge boson couplings (aTGCs), using the 2011 4.7 ${rm fb}^{-1}$ $pp$ collisions data at 7 TeV collected in 2011. The measurement allows for a stringent test of the non-Abelian $SU(2) times U(1)$ SM electroweak sector and probes new physics that could manifest itself through aTGCs that may alter the observed production cross section or kinematic distributions. This measurement also provides a good understanding of the irreducible background in searches for the Higgs boson through the $Hrightarrow W^{+}W^{-}$ decay channel.This thesis work has laid a solid foundation for further measurements of the WW production with the $sim$25 ${rm fb}^{-1}$ integrated luminosity 8 TeV recorded data expected by the end of 2012, which will further improve the precision and yield more stringent limits on the aTGCs.
529

Histologické řezy orgány myši a jejich využití ve výuce na střední škole / Histological Sections of Mouse Organs and their Usage in Secondary Education

Maratová, Klára January 2013 (has links)
This thesis is concerned with the topic of teaching histology at secondary schools. Histology is focused on the study of microscopic structure of tissue. By this it comprises the basic foundation stone for the studies of organs and organ systems not merely in humans, but also in other animals. The method of preparing the permanent histological slides, which has also been tested in practice, is thoroughly described in this thesis. The main goal of the practical part was to prepare a representative collection of the permanent histological sections through the organs of the house mouse (Mus muculus), to acquire its photo documentation as a base for an interactive histological atlas. House mouse (Mus musculus) was chosen as the model animal, because of its frequent utilization in various laboratory experiments and because this model mammal has the structure of tissues similar to human. The atlas consists of the photo documentation of histological sections through the following organs: lungs, skin, heart, thymus gland, spleen, epididymis, testicle, penis, spermatic sacs, striated muscle, heart muscle, smooth muscle, liver, tongue, pancreas, small intestine, large intestine, gall bladder, kidney, urinary bladder, urethra, cerebellum and hippocampus. The sections are stained with application of...
530

Géométrie et cinématique de l’avant-pays provençal : modélisation par coupes équilibrées dans une zone à tectonique polyphasée / Geometry and kinematic of the Provence foreland : Modeling by balanced cross section in a polyphase tectonic area

Bestani, Lucie 17 February 2015 (has links)
L’architecture structurale et l’évolution du bassin d’avant-pays Pyrénéo-Alpin de Provence sont contrôlées par des failles profondes héritées du rifting de Gondwana au cours du Permo-Trias, par des variations d’épaisseur de la pile sédimentaire mésozoïque et par l'alternance d’évènements tectoniques compressifs et extensifs qui ont affecté la zone depuis la fin du Paléozoïque. La construction de deux coupes équilibrées d’échelle régionale (~150 km) montre que le style tectonique de l’avant-pays provençal est dominé par une tectonique de socle en Provence orientale et par une tectonique de couverture en Provence occidentale, associé avec du diapirisme dans les deux domaines. Les deux domaines sont couplés à l’échelle crustale et séparés par une zone d'accommodation dans la couverture: la Faille de la Moyenne Durance, dont la partie profonde est héritée du Paléozoïque. La structure actuelle de l’avant-pays Pyrénéo-Alpin de Provence correspond essentiellement à la signature de la compression Pyrénéo-Provençale Crétacé supérieur-Eocène (>90%). La part de la déformation Alpine est minime (9%). La phase d'extension Oligocène entre ces deux périodes compressives a été quantifiée à 1.7%. Les données de traces de fission sur apatite suggèrent une exhumation régionale à ~80 Ma reliée à la compression Pyrénéenne. Les chevauchements pyrénéens principaux ont joué simultanément, comme l’indiquent l’âge et la répartition des séries sédimentaires syntectoniques. / The structural architecture and evolution of the Pyrenean-Alpine foreland of Provence are controlled by deep-seated basement faults inherited from Gondwana rifting during Permo-Triassic time, by variations in the Mesozoic sedimentary pile thickness and by alternating compressive and extensive tectonic events that affected the area since the late Paleozoic. The construction of two balanced cross sections at regional scale (~150 km) shows that the structural style of the Provence foreland is dominated by thick-skinned tectonic in eastern Provence and thin-skinned tectonic in western Provence, associated with diapirism in each domain. Both domains are coupled at crustal scale and separated by an accommodation zone in the cover: the Middle Durance Fault, whose deep-seated part is inherited from the Paleozoic. The current structure of the Pyrenean-Alpine foreland of Provence mainly corresponds to the Pyrenean-Provence compression signature during Late Cretaceous to Eocene (>90%). The Alpine deformation proportion is minor (9%). The Oligocene extension phase between these two compressive periods has been quantified at 1.7%. The apatite fission track data suggests an exhumation stage around 80 Ma related to the Pyrenean compression. The main Pyrenean thrusts were synchronous, as indicated by the age and distribution of syntectonic sedimentary series.

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