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Books > Science & Mathematics > Physics > Atomic & molecular physics
The collision of electrons with molecules and molecular ions is a fundamental pro cess in atomic and molecular physics and in chemistry. At high incident electron en ergies, electron-molecule collisions are used to deduce molecular geometries, oscillator strengths for optically allowed transitions, and in the case of electron-impact ionization, to probe the momentum distribution of the molecule itself. When the incident electron energy is comparable to or below those of the molecular valence electrons, the physics involved is particularly rich. Correlation and exchange effects necessary to describe such collision processes bear a close resemblance to similar efft: cts in the theory of electronic structure in molecules. Compound state formations, in the form of resonances and vir tual states, manifest themselves in experimental observables which provide details of the electron-molecule interactions. Ro-vibrational excitations by low-energy electron collisions exemplify energy transfer between the electronic and nuclear motion. The role of nonadiabatic interaction is raised here. When the final vibrational state is in the continuum, molecular dissociation occurs. Dissociative recombination and dissociative attachment are examples of such fragmentation processes. In addition to its fundamental nature, the study of electron-molecule collisions is also motivated by its relation to other fields of study and by its technological appli cations. The study of planetary atmospheres and the interstellar medium necessarily involve collision processes of electrons with molecules and molecular ions."
The NATO Advanced Study Institute on "Atomic and Molecular Processes in Controlled TheI'IllOnuclear Fusion" was held at Chateau de Bonas, Castera-Verduzan, Gel's, France, from 13th to 24th August 1979, and this volume contains the text of the invited lectures. The Institute was supported by the Scientific Affairs Division of NATO, and additional support was received from EURATOM and the United States National Science Foundation. The Institute was attended by 88 scientists, all of whom were active research workers in control of thermonuclear plasmas, 01' atomic and molecular physics, 01' both. In addition to the formal lectures, printed in this volume, which were intended to be pedagogic, more than twenty research seminars were given by participants. The first half of the Institute was directed to introducing atomic and molecular theoretical and experimental physicists to the physics of controlled thermonuclear fusion. Most attention was paid to magnetic confinement, and within that field, to tokamaks. MI'.
Volume 16 marks the beginning of a special topic series devoted to modern techniques in protein NMR, under the Biological Magnetic Resonance series. This volume is being followed by Volume 17 with the subtitle Structure Computation and Dynamics in Protein NMR. Volumes 16 and 17 present some of the recent, significant advances in biomolecular NMR field with emphasis on developments during the last five years. We are honored to have brought together in these volumes some of the world's foremost experts who have provided broad leadership in advancing this field. Volume 16 contains advances in two broad categories: the first, Large Proteins, Complexes, and Membrane Proteins, and second, Pulse Methods. Volume 17, which will follow covers major advances in Computational Methods, and Structure and Dynamics. In the opening chapter of Volume 16, Marius Clore and Angela Gronenborn give a brief review of NMR strategies including the use of long range restraints in the structure determination of large proteins and protein complexes. In the next two chapters, Lewis Kay and Ron Venters and their collaborators describe state-of-t- art advances in the study of perdeuterated large proteins. They are followed by Stanley Opella and co-workers who present recent developments in the study of membrane proteins. (A related topic dealing with magnetic field induced residual dipolar couplings in proteins will appear in the section on Structure and Dynamics in Volume 17).
There are many human cancers which actively synthesize specific characteristic proteins such as melanomas, thyroid cancer and squamous cell carcinoma. Many cancer researchers have of course tried to utilize this specific activity as a key for the selective treatment of cancers. In the past for example, the molecular hybrid compound of DOPA, a substrate of melanin, and nitrogen mustard N-oxide hydrochloride, a ctyotoxic anti-tumor drug, was synthesized as Melphalan and used to treat malignant melanoma. A major problem arose though in that it was soon found to be highly suppressive toward bone marrow and quite toxic while not being remarkably effective. Thus, malignant melanoma could not be cured by it. Such failure led us to develop a novel bimodal therapeutic system which includes the use of non-toxic potentially cytocidal chemicals which selectively accumulate within the cancer cells and which are converted by a controllable modality into an actively cytocidal element in situ. We can now non-surgically cure malignant melanoma and glioblastoma with our selective cancer treatment, neutron capture therapy (NCT); as can be found in this volume. Included are 124 papers on the latest breaking developments discussed at the Sixth International Symposium on NCT for Cancer held in Kobe during the late autumn of 1994.
The North Atlantic Treaty Organization (NATO) has sponsored research and personnel safety standards development for exposure to Radiofrequency Radiation (RFR) for over twenty years. The Aerospace Medical Panel of the Advisory Group For Aerospace Research and Development (AGARD) sponsored Lecture Series No. 78 Radiation Hazards,! in 1975, in the Netherlands, Germany, and Norway, on the subject of Radiation Hazards to provide a review and critical analysis of the available information and concepts. In the same year, Research Study Group 2 on Protection of Personnel Against Non-Ionizing Electromagnetic Radiation (Panel VIIl of AC/243 Defence Research Group, NATO) proposed a revision to Standardization Agreement (STANAG) 2345. The intent of the proposal was to revise the ST ANAG to incorporate frequency-dependent-RFR safety guidelines. These changes are documented in the NATO STANAG 2345 (MED), Control and Recording of Personnel Exposure to Radiofrequency Radiation,2 promulgated in 1979. Research Study Group 2 (RSG2) of NATO Defense Research Group Panel VIII (AC1243) was organized, in 1981, to study and contribute technical information concerning the protection of military personnel from the effects of radiofrequency electromagnetic radiation. A workshop at the Royal Air Force Institute of Aviation Medicine, Royal Aircraft Establishment, Farnborough, U. K. was held to develop and/or compile sufficient knowledge on the long-term effects of pulsed RFR to maintain safe procedures and to minimize unnecessary operational constraints.
This volume contains the proceedings of a NATO Advanced Study Institute which was held in Alghero, Sardinia, in July 1991. The development of computers in the recent years has lead to the emergence of unconventional ideas aiming at solving old problems. Among these, the possibility of computing directly fluid flows from the trajectories of constituent particles has been much exploited in the last few years: lattice gases cellular automata and more generally Molecular Dynamics have been used to reproduce and study complex flows. Whether or not these methods may someday compete with more traditional approaches is a question which cannot be answered at the present time: it will depend on the new computer architectures as well as on the possibility to develop very simple models to reproduce the most complex phenomena taking place in the approach of fully developed turbulence or plastic flows. In any event, these molecular methods are already used, and sometimes in an applied engineering context, to study strong shock waves, chemistry induced shocks or motion of dislocations in plastic flows, that is in domains where a fully continuum description appears insufficient. The main topic of our Institute was the molecular simulations of fluid flows. The project to hold this Institute was made three years ago, in the summer of 1989 during a NATO workshop in Brussels on the same subject.
The EPSRC (Engineering and Physical Science Research Committee of the U. K. ) suggested two Workshops (York University, 22-23 September, 1993 and 15-16 April, 1994) for possible development of polarized electron/photon physics as targeted areas of research. The remit of these meetings included identifying research groups and their activities in polarized electron/polarized photon physics, listing relevant existing facilities (particularly electron spin sources and polarimeters), possible joint projects between research groups in the U. K. , recognizing future needs of projects for research of the highest scientific merit and referring to international comparisons of these research activities. Although very diverse but interconnected, the areas of research presented at the Workshops embrace atomic, molecular, surface, and solid state physics. In more detail these areas covered: electron spin correlations and photon polarization correlations in atomic and molecular collisions and photoionization, electron spin effects in scanning tunneling microscopy, surface and interface magnetism from X-ray scattering and polarized Auger electrons (including analysis of domain structures in solids and surfaces), polarized electrons from multiphoton ionization, quasi-atomic effects in solid state physics, dichroism in molecular and surface processes, Faraday rotation and high-field magneto-optics and polarization effects in simultaneous higher order electron-photon excitations. It is obvious from the spectrum of research fields presented at the Workshops that physicists of primarily two communities, namely those studying electron and photon spin interactions with gaseous atomic and molecular targets and those using condensed matter targets for their studies, interacted very closely with each other.
The first Nato Advanced Studies Institute entirely devoted to density functional theory was held in Portugal in September 1983. The proceedings of this School, publis hed in early 1985, is still used as a standard reference covering the basic development of the theory and applications in atomic, molecular, solid state and nuclear physics. Ho wever, astonishing progress has been achieved in the intervening years: The foundations of the theory have been extended to cover excited states and time dependent problems more fully, density functional theory of classical liquids and superconducting systems has been addressed and extensions to relativistic, that is, field theoretical systems, as well as a more thorough discussion of magnetic field problems have been presented. In addition, new functionals have been devised, for instance under the heading of ge neralised gradient expansions, and the number of applications in the traditional fields has steadily increased, in particular in chemistry. Applications in new fields, as for instance the structure of atomic clusters and the marriage of density functional theory with molecular dynamics and simulated annealing, have provided additional impetus to the field of density functional theory."
It was just over ten years ago, at Aspeniisgarden near Gothenburg, Sweden, that Pro fessor Alexandr Sergeevich Davydov presented his soliton theory for the storage and transport of biological energy in protein to scientists from Europe, North America and Japan. Since then, his ideas have been vigorously studied and investigated throughout the world. Many feel that Davydov's theory is an important contribution to biomolecu lar dynamics, but others caution that neglected dispersive effects may destroy the energy localization that arises ill his theory. It was to discuss these differences of opinion that we organized a NATO Advanced Research Workshop on "Self-trapping of Vibrational Energy in Protein" from July 30 to August 5, 1989 at Hanstholm, Denmark. In addition to substantial financial support from the Special Programme on "Chaos; Order and Patterns" of the NATO Scientific Affairs Division, we received it generous grant from the Danish Natural Science Research Council. We also acknowledge invalu able assistance provided by the interdepartmental center of nonlinear studies ("MIDIT" is the Danish acronym) as well as the Laboratory of Applied Mathematical Physics, both at the Technical University of Denmark. It is a particular pleasure to thank Lise Gudmandsen and Dorthe Thcentsgersen for many forms of assistance before, during, and after the workshop."
This series, Finite Systems and Multipartide Dynamics, is intended to provide timely reviews of current research topics, written in a style sufficient ly pedagogic so as to allow a nonexpert to grasp the underlying ideas as well as understand technical details. The series is an outgrowth of our involvement with three interdisciplin ary activities, namely, those arising from the American Physical Society's Topical Group on Few-Body Systems and Multipartide Dynamics, the series of Gordon Research Conferences first known by the title "Few-Body Problems in Chemistry and Physics" and later renamed "Dynamics of Simple Systems in Chemistry and Physics," and the series of Sanibel Symposia, sponsored in part by the University of Florida. The vitality of these activities and the enthusiastic response to them by researchers in various subfields of physics and chemistry have convinced us that there is a place-even a need-for a series of timely reviews on topics of interest not only to a narrow band of experts but also to a broader, interdisciplinary readership. lt is our hope that the emphasis on pedagogy will permit at least some of the books in the series to be useful in graduate-level courses. Rather than use the adjective "Few-Body" or "Simple" to modify the word "Systems" in the title, we have chosen "Finite. " It better expresses the wide range of systems with which the reviews of the series may deal.
Developed from the Global Foundation's International Conference on Environment and Nuclear Energy, held in October 1997, this volume examines the impact of nuclear energy on regional and global environmental issues under a variety of scenarios. These include competition in deregulated energy environments, constraints levied upon use of fossil energy, and possible expansion of nuclear power into energy sectors beyond the generation of electricity, process heat, and fuels production. It also assesses the overall role of nuclear energy in meeting future energy needs arising from growing world populations and economic development.
This book collects the lectures given at the NATO Advanced Study Institute on "Atoms in Strong Fields," which took place on the island of Kos, Greece, during the two weeks of October 9-21,1988. The designation "strong field" applies here to an external electromagnetic field that is sufficiently strong to cause highly nonlinear alterations in atomic or molecular struc ture and dynamics. The specific topics treated in this volume fall into two general cater gories, which are those for which strong field effects can be studied in detail in terrestrial laboratories: the dynamics of excited states in static or quasi-static electric and magnetic fields; and the interaction of atoms and molecules with intense laser radiation. In both areas there exist promising opportunities for research of a fundamental nature. An electric field of even a few volts per centimeter can be very strong on the atom ic scale, if it acts upon a weakly bound state. The study of Rydberg states with high reso lution laser spectroscopic techniques has made it possible to follow the transition from weak-field to strong-field behavior in remarkable detail, using static fields of modest lab oratory strength; in the course of this transition the atomic system evolves from one which can be thoroughly understood in terms of field-free quantum numbers, to one which cannot be meaningfully associated at all with the zero-field states of the atom."
In this unique textbook and reference source, the authors integrate theoretical and applied research from a host of disciplines, including materials science, plasma physics, and advanced transport phenomena. Volume 1, the first of two, covers the fundamentals of plasma physics and gaseous electronics, thermodynamics, and transport properties of plasma.
During the last two decades the experimental investigation of atomic coherence phenomena has made rapid progress. Detailed studies have been performed of angular correlations, spin polarization effects, angular momen tum transfer, and the alignment parameters which characterize the charge cloud of excited atoms. The enormous growth in the number of these investigations was made possible through substantial development and application of new experimental technology, the development of sophisti cated theoretical models and numerical methods, and a fine interplay between theory and experiment. This interplay has resulted in a deeper understanding of the physical mechanisms of atomic collision processes. It is the purpose of the chapters in this book to provide introductions for nonspecialists to the various fields of this area as well as to present new experimental and theoretical results and ideas. The interest in spin-dependent interactions in electron-atom scattering has a long history; it dates back to the early investigations of Mott in 1929. While the more traditional measurements in this field were concerned with the determination of spin polarization and asymmetries, the range of investi gations has been expanded enormously during the last few years and now includes many observables sensitive to one or more of the various spin dependent interactions. The understanding of these effects requires a theoretical description of the orientation and alignment parameters of the target atoms, of the forma tion of resonances, of the influence of electron-exchange processes, and of the relativistic interactions inside the atom and between projectile and target."
The great advantage of coincidence measurements is that by suitable choice of the kinematical and geometrical arrangement one may probe delicate physical effects which would be swamped in less differential experiments. The measurement of the triple dif ferential and higher-order cross sections presents enormous technical difficulties, but refined experiments of this type provide an insight into the subtleties of the scattering process and offer a welcome, if severe, test of the available theoretical models. The last few years have been an exciting time to work in the field and much has been learned. Profound insights have been gleaned into the basic Coulomb few body problem in atomic physics: the experimental study of the fundamental (e,2e) processes on hydrogen and helium targets continues to add to our knowledge and indeed to challenge the best of our theoretical models; significant advances have been made in the understanding of the "double excitation problem," that is the study of ionization processes with two active target electrons: important measurements of (e,3e), (, ), 2e), excitation-ionization and excitation autoionization have been reported and strides have been made in their theoretical description; the longstanding discrepancies between theory and experiment for relativistic (e,2e) processes were resolved, spin dependent effects predicted and ob served and the first successful coincidence experiments on surfaces and thin films were announced. Theory and experiment have advanced in close consort. The papers pre sented here cover the whole gambit of research in the field. Much has been achieved but much remains to be done."
The present volume is a continuation ofthe EL.B.A. Forum Series which was initiated in the spring of 1992 in Marciana Marina (Italy), with the first volume entitled From Neural Networks and Biomolecu/ar Engineering to Bioelectronics published by Plenum Press in 1995. Bioelectronics-miginally introduced in April, 1987, at a symposium hosted by CIREF, a research consortium among leading high tech industries in Novara (Italy)---was later defined in two successive consensus reports at the first (Bruxelles, 1991) and second (Frankfurt, 1994) European Union Workshops on this widely interdisciplinary field, as "the use ofbiological materials and biological architectures for information processing and sens- ing systems and devices down to molecular Ievel." lt is worth noting that these workshops gave birth to the first European research program on "lnterfacing Biology with Electronics" during 1996-1999, following the !arge Programma Nazionale Ricerca on "Technologies for Bioelectronics" launched by the ltalian Ministry ofUniversities and Research in 1990. In autumn, 1996, with the second volume, entitledMolecular Manufacturing, the em- phasis was placed on the ernerging parallel area of nanotechnology, independently initiated in Palo Alto, Zurich, Genova, Mainz, and Tokyo by various groups (i.e., IBM, Xerox, Polo Nazionale Bioelettronica, Max Planck Institutes), universities (i.e., Stanford, Genova, Rice, Tokyo), and organizations (i.e., Foresight, Erato, Fondazione EL.B.A., Frontiers Research, MITI) of different sizes, scopes, and latitudes.
"The Fundamentals of Atomic and Molecular Physics" is intended as an introduction to the field for advanced undergraduates who have taken quantum mechanics. Each chapter builds upon the previous, using the same tools and methods throughout. As the students progress through the book, their ability to use these tools will steadily increase, along with their confidence in their efficacy. The book treats the two-electron atom as the simplest example of the many-electron atom-as opposed to using techniques that are not applicable to many-electron atoms-so that it is unnecessary to develop additional equations when turning to multielectron atoms, such as carbon. External fields are treated using both perturbation theory and direct diagonalization and spontaneous emission is developed from first principles. Only diatomic molecules are considered with the hydrogen molecular ion and neutral molecule treated in some detail. This comprehensive coverage of the quantum mechanics of complex atoms and simple diatomic molecules, developed from the very basic components, is extremely useful for students considering graduate studies in any area of physics.
In this introductory chemical physics textbook, the authors discuss the interactions, bonding, electron density, and experimental techniques of free molecules, and apply spectroscopic methods to determine molecular parameters, dynamics, and chemical reactions.
For the first half of the 20th Century, low-energy nuclear physics was one of the dominant foci of all of science. Then accelerators prospered and energies rose, leading to an increase of interest in the GeV regime and beyond. The three articles comprising this end-of-century Advances in Nuclear Physics present a fitting and masterful summary of the energy regimes through which nuclear physics has developed and promises to develop in future. One article describes new information about fundamental symmetries found with kV neutrons. Another reviews our progress in understanding nucleon-nucleus scattering up to 1 GeV. The third analyzes dilepton production as a probe for quark-gluon plasmas generated in relativistic heavy-ion collisions.
The 1995 conference was organized around two closely related themes and focused on the two pivotal aspects of energy, that is, economics and politics, both of which are decisive in providing long-term national and international strategies for the next century. Originally the program was going to include the participants from the new oil powers in Central Asia and Caucasus, newly independent from the former U.S.S.R. However, probably both economics and politics prevented their participation. Global energy projections, technological changes such as nuclear power and the fuel geopolitics of the coming century will be the basis for political and strategic planning. Based on the scenarios of likely global economic and population growth and of new energy technologies, what are foreseeable scenarios for the geopolitics of energy a half century ahead? What fresh worldwide systems should we start now? The political problems with profound economic impact could include, for example, the significance of the continuing worldwide growth of nuclear power, with such issues as the use of Highly Enriched Uranium (HEU) and Plutonium obtained from the dismantling of U.S. and former U.S.S.R. nuclear weapons; the urgency of nonproliferation; the disposal of civilian and military nuclear waste; and, nuclear power alternatives. In spite of U.S. reluctance, the increasing role of nuclear power is becoming apparent in several countries, and its potential has become an important political factor today.
The first volume in this series appeared in 1977, the second in 1980. From these volumes and the present one, some research trends in chemical communication can be perceived. In the 1977 volume, studies on 13 animal taxa were reported. In the present volume, the number is 25. This taxonomie diversi fication of research since the first volume of this series demon strates the wide variety of ecological adaptions, although no new general principles of chemical communication have ernerged. Further more, divergences in chemical comrnunication below the species level have become more apparent. In general, more sophisticated observa tions and techniques have led to greater awareness of the com plexities in chemical communication. As such awareness has also developed in the field of insect chemical communication, there has been a corresponding increase in the identification of the chemical compounds involved. However, in the vertebrates, no such correlation exists; in the present volume, conclusive chemical identifications of semiochemicals are remarkable by their paucity.
The primary objective of the book on "Contemporary Topics in Medium Energy Physics" is to help the reader in exploring important frontier research, as of the year of 1992, in the area of medium energy physics. The book is the result of the multi-pronged efforts by the authors who were invited to speak at the Second German Chinese Symposium on "Medium Energy Physics" (September 7-10, 1992, Bochum, Germany). The premise of the meeting is to investigate primarily how quantum chromo dynamics (QCD), the candidate theory of strong interactions, manifests itself in high energy and nuclear physics. This book is divided into four parts: (i) field-theoretic treatments in QCD; (ii) effective chirally symmetric models and QCD; (iii) electroweak physics in general; and (iv) topological solutions. The focus is more on exposition of new ideas, rather than a comprehensive review of the current status, concerning these subjects, as of the year of 1992. As there are many distinctly different research areas in contemporary intermediate energy physics, we could only choose a few topics of current interest, especially those which are related, directly or indirectly, to the structural studies of the nucleon (proton or neutron). Fortunately, there are in recent years merging trends in these studies: There is a call for an alternative, and more efficient, method to handle problems related to strong interactions (as described by QCD). This is the focus of the papers included in Part I."
This volume represents the fIrst of a series of proceedings of the EL.B.A. Forum on Bioelectronics, a scientifIc discipline at the frontiers of Advanced Electronics and Biotechnology. The name for these forums derives not only from the place (the Isle of Elba in Italy), where the conferences have been held every 6 months since 1991, but also from an acronym: Electronics and Biotechnology Advanced. Bioelectronics is intended as "the use of biological materials and biological architectures for information processing and sensing systems and devices down to molecular level" and focuses its attention on three major areas: I New hardware architectures borrowed from the thorough study of brain and sensory systems down to the molecular level, utilizing existing semiconductor inorganic materials (both GaAs and Si) and giga-scale integration; II Protein Engineering, especially of systems involved in electron transfer and molecular recognition, integrated with Metabolism and Chemical Engineering, to develop new biomaterials by learning basic rules of macromolecular folding and self-assembly; m Sensors, thin film and electronic devices utilizing organic compounds and biopolymers, and by implementing nanotechnology bottom up through manufacturing and characterization at the atomic level.
The International Conference on Strongly Coupled Coulomb Systems was held on the campus of Boston College in Newton, Massachusetts, August 3-10, 1997. Although this conference was the first under a new name, it was the continuation of a series of international meetings on strongly coupled plasmas and other Coulomb systems that started with the NATO Summer Institute on Strongly Coupled Plasmas, almost exactly twenty years prior to this conference, in July of 1977 in Orleans la Source, France. Over the intervening period the field of strongly coupled plasmas has developed vigorously. In the 1977 meeting the emphasis was on computer (Monte Carlo and molecular dynamics) simulations which provided, for the first time, insight into the rich and new physics of strongly coupled fully ionizedplasmas. While theorists scrambled to provide a theoretical underpinning for these results, there was also a dearth of real experimental input to reinforce the computer simulations. Over the past few years this situation has changed drastically and a variety of direct experiments on classical, pure, strongly correlated plasma systems (charged particle traps, dusty plasmas, electrons on the surface of liquid helium, etc. ) have become available. Even more importantly, entire new area of experimental interest in condensed matter physics have opened up through developments in nano-technology and the fabrication of low-dimensional systems, where the physical behavior, in many ways, is similar to that in classical plasmas. Strongly coupled plasma physics has always been an interdisciplinaryactivity. |
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