Download or read book Effets spin orbite g ants sur les modes collectifs de spin de puits quantiques written by Florent Baboux and published by . This book was released on 2013 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cette thèse est consacrée à l'étude des effets du couplage spin-orbite dans des puits quantiques semi-conducteurs dopés (GaAs et CdMnTe), par spectroscopie Raman électronique. Dans ces structures existent des champs magnétiques intrinsèques (Dresselhaus et Rashba). Ces champs offrent des moyens attractifs pour manipuler le spin des électrons, mais contribuent aussi à la relaxation de spin via leur dépendance avec le vecteur d'onde de l'électron (mécanisme D'yakonov-Perel'). Nous montrons que pour les modes collectifs de spin de puits quantiques, le scénario destructif D'yakonov-Perel' est transformé en un scénario constructif : les interactions Coulombiennes font émerger un champ spin-orbite collectif, proportionnel au vecteur d'onde de l'excitation, et renforcé d'un facteur de plusieurs unités par rapport aux champs spin-orbite individuels. Nous mettons d'abord en évidence ces effets spin-orbite géants sur le plasmon de spin inter-sous-bande, dans des puits quantiques de GaAs. Le champ spin-orbite collectif, qui conduit à un éclatement de structure fine du spectre plasmon, est superposé à un champ magnétique extérieur et cartographié dans l'espace réciproque. Nous étudions ensuite l'onde de spin intra-sous-bande du gaz d'électrons polarisé en spin, dans des puits quantiques magnétiques dilués de CdMnTe. Le champ spin-orbite collectif se superpose ici au champ Zeeman géant du composé. Nous mesurons le facteur de renforcement du champ spin-orbite collectif. Enfin, nous démontrons la possibilité de contrôler l'amplitude du champ spin-orbite collectif à l'aide d'une grille optique et nous mesurons la dépendance du facteur de renforcement avec la densité électronique.
Download or read book ICREEC 2019 written by Ahmed Belasri and published by Springer Nature. This book was released on 2020-06-10 with total page 659 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights peer reviewed articles from the 1st International Conference on Renewable Energy and Energy Conversion, ICREEC 2019, held at Oran in Algeria. It presents recent advances, brings together researchers and professionals in the area and presents a platform to exchange ideas and establish opportunities for a sustainable future. Topics covered in this proceedings, but not limited to, are photovoltaic systems, bioenergy, laser and plasma technology, fluid and flow for energy, software for energy and impact of energy on the environment.
Download or read book LIGHT AND ITS INTERACTIONS WITH MATTER written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Introduction to Differential Manifolds written by Jacques Lafontaine and published by Springer. This book was released on 2015-07-29 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an introduction to differential manifolds. It gives solid preliminaries for more advanced topics: Riemannian manifolds, differential topology, Lie theory. It presupposes little background: the reader is only expected to master basic differential calculus, and a little point-set topology. The book covers the main topics of differential geometry: manifolds, tangent space, vector fields, differential forms, Lie groups, and a few more sophisticated topics such as de Rham cohomology, degree theory and the Gauss-Bonnet theorem for surfaces. Its ambition is to give solid foundations. In particular, the introduction of “abstract” notions such as manifolds or differential forms is motivated via questions and examples from mathematics or theoretical physics. More than 150 exercises, some of them easy and classical, some others more sophisticated, will help the beginner as well as the more expert reader. Solutions are provided for most of them. The book should be of interest to various readers: undergraduate and graduate students for a first contact to differential manifolds, mathematicians from other fields and physicists who wish to acquire some feeling about this beautiful theory. The original French text Introduction aux variétés différentielles has been a best-seller in its category in France for many years. Jacques Lafontaine was successively assistant Professor at Paris Diderot University and Professor at the University of Montpellier, where he is presently emeritus. His main research interests are Riemannian and pseudo-Riemannian geometry, including some aspects of mathematical relativity. Besides his personal research articles, he was involved in several textbooks and research monographs.
Download or read book Aeronomy written by P. M. Banks and published by Elsevier. This book was released on 2013-09-24 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aeronomy, Part A is an attempt to make a comprehensive exposition of the processes in aeronomy, the study of composition, movement, and thermal balance of the upper regions of the planetary atmosphere. The text covers topics such as atmospheric regions and atmospheric density, the temperature and molecular mass of the atmosphere; the permanent constituents and the molecular and isotonic composition of the homosphere; and the transition from the homosphere to the heterosphere. Also covered are topics such as the temperature gradient and energies in the thermosphere, conditions at 200km and above 250km, solar radiation and ionization, and aeronomic reactions. The book is recommended for scientists, especially natural physicists, who would like to know more about the field of aeronomy and its advances.
Download or read book Organic Solid State Lasers written by Sébastien Forget and published by Springer. This book was released on 2013-07-03 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic lasers are broadly tunable coherent sources, potentially compact, convenient and manufactured at low-costs. Appeared in the mid 60’s as solid-state alternatives for liquid dye lasers, they recently gained a new dimension after the demonstration of organic semiconductor lasers in the 90's. More recently, new perspectives appeared at the nanoscale, with organic polariton and surface plasmon lasers. After a brief reminder to laser physics, a first chapter exposes what makes organic solid-state organic lasers specific. The laser architectures used in organic lasers are then reviewed, with a state-of-the-art review of the performances of devices with regard to output power, threshold, lifetime, beam quality etc. A survey of the recent trends in the field is given, highlighting the latest developments with a special focus on the challenges remaining for achieving direct electrical pumping of organic semiconductor lasers. A last chapter covers the applications of organic solid-state lasers.
Download or read book Minimum competence in scientific English written by Sue Blattes and published by L'Editeur : EDP Sciences. This book was released on 2003 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cet ouvrage, devenu célèbre sous son sigle MCSE, a déjà été utilisé par plus de 50 000 étudiants, chercheurs, professionnels. L'objectif est de lire et écrire des textes en anglais scientifique avec facilité et pertinence. L'ouvrage est conçu pour que l'apprenant devienne un véritable utilisateur de l'anglais. La méthode originale repose sur l'analyse des fonctions et structures nécessaires : measurement, frequency, comparison, modification, link words, time, cause and consequence, hypothesis, modality, purpose and process, impersonal forms, compound nouns and adjectives. Dans chaque unit, des tests d'auto-évaluation permettent de se situer et de construire son parcours de formation, d'abord en définissant ses objectifs à l'aide des key points et du lexis, puis, de façon plus personnalisée, en puisant dans les examples in context, checkpoints (back to basics, word web), web search, FAQs... MCSE est l'outil de base d'une méthode qui comprend aussi d'autres outils dans la même collection (Listening Comprehension for Scientiflc English et Speaking Skills in Scientitic English). L'ouvrage est destiné à tout apprenant de niveau baccalauréat qui désire acquérir une réelle compétence dans l'écriture et la lecture de textes en anglais scientifique.
Download or read book The Interference Of Electrons written by P Debye and published by Palala Press. This book was released on 2018-03-02 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Download or read book Popular Astronomy written by Camille Flammarion and published by . This book was released on 1894 with total page 732 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser 50 Years Of Discoveries written by Fabien Bretenaker and published by World Scientific. This book was released on 2014-10-27 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: This unique book provides an overview of the principle and applications of lasers enriched with numerous illustrations.Being over fifty years old, lasers continue to amaze us. Their performance characteristics are constantly reaching new limits, and the scope of their applications continues to expand. Yet, it took years of effort by teams of physicists to transform the fundamental notions of Einstein into the first experimental beam of laser light. And history is still going on as fundamental research is now triggered by its remarkable properties.This book addresses every aspects of laser light, from its fundamental principles to its industrial applications, at a level particularly suited for high school teachers, students, and anybody curious about science and technology.
Download or read book Unidentified written by Robert Salas and published by Career Press. This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1969 the U.S. Air Force issued a statement that read' "No UFO reported, investigated and evaluated by the Air Force was ever an indication of threat to our national security." This statement is patently false. It has been proven untrue by the testimony of many military officers and airmen and documentation of incidents involving UFOs and nuclear weapons, testimonies of which the U.S. Air Force was fully aware. Unidentified details many of these testimonies, some for the first time. As partial justification for its position, the Air Force cites a University of Colorado study that was contracted and paid for by federal funds. Unidentified reveals how this study was actually just another part of the plan to cover up the reality of the UFO phenomenon. For the first time, Unidentified publishes evidence that the investigators for the Colorado study knew about the UFO-related missile shutdown incidents but did not investigate them or include them in their final report.
Download or read book Science and Anti science written by Gerald James Holton and published by Harvard University Press. This book was released on 1993 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: What is good science? What goal--if any--is the proper end of scientific activity? Is there a legitimating authority that scientists mayclaim? Howserious athreat are the anti-science movements? These questions have long been debated but, as Gerald Holton points out, every era must offer its own responses. This book examines these questions not in the abstract but shows their historic roots and the answers emerging from the scientific and political controversies of this century. Employing the case-study method and the concept of scientific thematathat he has pioneered, Holton displays the broad scope of his insight into the workings of science: from the influence of Ernst Mach on twentiethcentury physicists, biologists, psychologists, and other thinkers to the rhetorical strategies used in the work of Albert Einstein, Niels Bohr, and others; from the bickering between Thomas Jefferson and the U.S. Congress over the proper form of federal sponsorship of scientific research to philosophical debates since Oswald Spengier over whether our scientific knowledge will ever be "complete." In a masterful final chapter, Holton scrutinizes the "anti-science phenomenon," the increasingly common opposition to science as practiced today. He approaches this contentious issue by examining the world views and political ambitions of the proponents of science as well as those of its opponents-the critics of "establishment science" (including even those who fear that science threatens to overwhelm the individual in the postmodern world) and the adherents of "alternative science" (Creationists, New Age "healers," astrologers). Through it all runs the thread of the author's deep historical knowledge and his humanistic understanding of science in modern culture. Science and Anti-Science will be of great interest not only to scientists and scholars in the field of science studies but also to educators, policymalcers, and all those who wish to gain a fuller understanding of challenges to and doubts about the role of science in our lives today.
Download or read book Giant Molecules written by Herman Francis Mark and published by . This book was released on 1970 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Beyond the Crisis written by Henry M. Greenberg and published by . This book was released on 1994 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: The question of health care in the United States has propelled a demand for reform, and sparked a frenzied debate as to the structure of that reform.
Download or read book Green Delusions written by Martin W. Lewis and published by Duke University Press. This book was released on 1992 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scholars, politicians, and activists worldwide are finally recognizing the severity of the global environmental crisis, yet serious threats to the environmental movement remain. Anti-environmentalists dismiss the very idea of a "crisis" as a mirage. Much less obvious, however, is the more subtle threat masquerading under the mantle of environmentalism itself. It is this threat that Green Delusions addresses. Writing from the standpoint of a committed environmentalist, Martin W. Lewis contends that many of the most devoted and strident "greens," those who propose a radical environmentalism, unwittingly espouse an ill-conceived doctrine that has devastating implications for the global ecosystem. In this book he distinguishes the main variants of eco-extremism, exposes the fallacies upon which such views ultimately flounder, and demonstrates that the policies advocated by their proponents would, if enacted, result in unequivocal ecological disaster. At once polemic and prescriptive, Green Delusions is an impassioned attempt to defend the environmental movement against extremist ideas that would lead to self-defeating political strategies.
Download or read book Lost Secrets of the Sacred Ark written by Laurence Gardner and published by HarperCollins UK. This book was released on 2004 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Ark of the Covenant is the source of one of the deepest mysteries of the Western world. Laurence Gardner has accessed Rosicrucian archives to reveal where the Ark is, what it is and how this lost secret of the distant past has led to the phenomenal new science of space-time manipulation.
Download or read book UFOs are Real written by Clifford E. Stone and published by S.P.I. Books. This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
