Atomfysik og molekylær fysik

In recent decades, time-dependent density functional theory has been developed for computing excited-state properties of large-scale systems to high accuracy in biomolecules and nanomaterials, especially for ab initio nonadiabatic molecular dynamic simulations. It is therefore regarded as a most unique efficient method to do accurate simulation for large complex systems.This book compiles and details cutting-edge research in quantum chemistry and chemical physics from interdisciplinary groups from Japan, China, South Korea, the United States, Hong Kong, and Taiwan. These groups are developing excited-state dynamics methods involving conical intersections and intersystem crossings for large complex systems. Edited by Chaoyuan Zhu, a prominent chemical physics researcher, this book will appeal to anyone involved in molecular dynamics and spectroscopy, photochemistry, biochemistry, and materials chemistry research.

This is a problem-oriented introduction to the main ideas, methods, and problems needed to form a basic understanding of the theory of strong interactions.

This book provides a detailed description of the modern variational methods available for solving the nuclear motion Schrödinger equation to enable accurate theoretical spectroscopy of polyatomic molecules.

In the summer of 1964, a reclusive young professor at the University of Edinburgh wrote two scientific papers which have come to change our understanding of the most fundamental building blocks of matter and the nature of the universe. Peter Higgs posited the existence an almost infinitely tiny particle - today known as the Higgs boson - which is the key to understanding why particles have mass, and but for which atoms and molecules could not exist.For nearly 50 years afterwards, some of the largest projects in experimental physics sought to demonstrate the physical existence of the boson which Higgs had proposed. Sensationally, confirmation came in July 2012 at the Large Hadron Collider at CERN in Geneva. The following year Higgs was awarded the Nobel Prize for Physics. One of the least-known giants of science, he is the only person in history to have had a single particle named for them.This revelatory book is 'not so much a biography of the man but of the boson named after him'. It brilliantly traces the course of much of twentieth-century physics from the inception of quantum field theory to the completion of the 'standard model' of particles and forces, and the pivotal role of Higgs's idea in this evolution. It also investigates the contested history of Higgs's responsibility for the breakthrough when there were others close by, and explains why the boson is named for him alone. Competition between institutions and states, Close shows, then played as much of a role in creating Higgs's fame as his work itself. Drawing on conversations with Higgs over a decade (a figure generally as elusive as his particle) this is a superb study of a scientist and his era - and of how scientific knowledge advances.

This book aims at providing a solid basis for the education of the next generation of researchers in hot, dense QCD (Quantum ChromoDynamics) matter. This is a rapidly growing field at the interface of the smallest, i.e. subnuclear physics, and the largest scales, namely astrophysics and cosmology. The extensive lectures presented here are based on the material used at the training school of the European COST action THOR (Theory of hot matter in relativistic heavy-ion collisions).The book is divided in three parts covering ultrarelativistic heavy-ion collisions, several aspects related to QCD, and simulations of QCD and heavy-ion collisions. The scientific tools and methods discussed provide graduate students with the necessary skills to understand the structure of matter under extreme conditions of high densities, temperatures, and strong fields in the collapse of massive stars or a few microseconds after the big bang. In addition to the theory, the set of lectures presents hands-on material that includes an introduction to simulation programs for heavy-ion collisions, equations of state, and transport properties.

This book highlights the advances and trends in the safety analysis of sodium-cooled fast reactors, especially from the perspective of particle bed-related phenomena during core disruptive accidents. A sodium-cooled fast reactor (SFR) is an optimized candidate of the next-generation nuclear reactor systems. Its safety is a critical issue during its R&D process. The book elaborates on research progresses in particle bed-related phenomena in terms of the molten-pool mobility, the molten-pool sloshing motion, the debris bed formation behavior, and the debris bed self-leveling behavior. The book serves as a good reference for researchers, professionals, and postgraduate students interested in sodium-cooled fast reactors. Knowledge provided is also useful for those who are engaging in severe accident analysis for lead-cooled fast reactors and light water reactors.

This monograph shares a newly emerging point of view among researchers and students in the field of materials science. Inspired by the presence of precisely determined molecular-level sequence structures in a wide range of biomolecules, a growing number of synthetic compounds with the same structural feature are appearing day by day. These examples in the interdisciplinary areas of materials science are collected in this monograph to provide readers with a good understanding of the state-of-the-art accessible structural level, characteristic features, and future potentials of these types of compounds. The major target audience of this monograph include Ph.D. students and researchers who have just begun their careers, who are seeking novel research directions, ideas, and inspiration. Among the diverse examples of synthetic molecular sequences referred to in the monograph, experienced experts can also find work that is informative and relevant to their own research, making the book worthwhile reading for these specialists.

This book examines foundational theories in chemical kinetics, taking a hands-on approach that bridges from theory to application. Aimed at senior undergraduate and graduate students, this book focuses on theories that provide insights into basic physical principles that govern the rates of chemical reactions both in the gas phase and in solution.

Novel approach to the theory of signals and systems in an introductory, accessible textbookSignals and Systems have the reputation of being a difficult subject. Essentials of Signals and Systems is a standalone textbook aiming to change this reputation with a novel approach to this subject, teaching the essential concepts of signals and systems in a clear, friendly, intuitive, and accessible way.The overall vision of the book is that traditional approaches to signals and systems are unnecessarily convoluted, and that students' learning experiences are much improved by making a clear connection between the theory of representation of signal and systems, and the theory of representation of vectors and matrices in linear algebra. The author begins by reviewing the theory of representation in linear algebra, emphasizing that vectors are represented by different coordinates when the basis is changed, and that the basis of eigenvectors is special because it diagonalizes the operator. Thus, in each step of the theory of representation of signals and systems, the author shows the analogous step in linear algebra. With such an approach, students can easily understand that signals are analogous to vectors, that systems are analogous to matrices, and that Fourier transforms are a change to the basis that diagonalizes LTI operators.The text emphasizes the key concepts in the analysis of linear and time invariant systems, demonstrating both the algebraic and physical meaning of Fourier transforms. The text carefully connects the most important transforms (Fourier series, Discrete Time Fourier Transform, Discrete Fourier Transforms, Laplace and z-transforms), emphasizing their relationships and motivations. The continuous and discrete time domains are neatly connected, and the students are shown step-by-step how to use the fft function, using simple examples.Incorporating learning objectives and problems, and supported with simple Matlab codes to illustrate concepts, the text presents to students the foundations to allow the reader to pursue more advanced topics in later courses.Developed from lecture notes already tested with more than 600 students over six years, Essentials of Signals and Systems covers sample topics such as:* Basic concepts of linear algebra that are pertinent to signals and systems.* Theory of representation of signals, with an emphasis on the notion of Fourier transforms as a change of basis, and on their physical meaning.* Theory of representation of linear and time invariant systems, emphasizing the role of Fourier transforms as a change to the basis of eigenvectors, and the physical meaning of the impulse and frequency responses.* What signals and systems have to do with phasors and impedances, and the basics of filter design.* The Laplace transform as an extension of Fourier transforms.* Discrete signals and systems, the sampling theorem, the Discrete Time Fourier Transform (DTFT), the Discrete Fourier Transform (DFT), and how to use the fast fourier transform (fft).* The z-transform as an extension of the Discrete Time Fourier Transform.Essentials of Signals and Systems is an immensely helpful textbook on the subject for undergraduate students of electrical and computer engineering. The information contained within is also pertinent to those in physics and related fields involved in the understanding of signals and system processing, including those working on related practical applications.

Understanding Molecular Simulation explains molecular simulation from a chemical-physics and statistical-mechanics perspective. It highlights how physical concepts are used to develop better algorithms and expand the range of applicability of simulations. Understanding Molecular Simulation is equally relevant for those who develop new code and those who use existing packages. Both groups are continuously confronted with the question of which computational technique best suits a given application. Understanding Molecular Simulation provides readers with the foundational knowledge they need to learn about, select and apply the most appropriate of these tools to their own work. The implementation of simulation methods is illustrated in pseudocodes, and their practical use is shown via case studies presented throughout the text. Since the second edition's publication, the simulation world has expanded significantly: existing techniques have continued to develop, and new ones have emerged, opening up novel application areas. This new edition aims to describe these new developments without becoming exhaustive; examples are included that highlight current uses, and several new examples have been added to illustrate recent applications. Examples, case studies, questions, and downloadable algorithms are also included to support learning. No prior knowledge of computer simulation is assumed.

Monte Carlo methods have been very prominent in computer simulation of various systems in physics, chemistry, biology, and materials science. This book focuses on the discussion and path-integral quantum Monte Carlo methods in many-body physics and provides a concise but complete introduction to the Metropolis algorithm and its applications in these two techniques. To explore the schemes in clarity, several quantum many-body systems are analysed and studied in detail. The book includes exercises to help digest the materials covered. It can be used as a tutorial to learn the discussion and path-integral Monte Carlo or a recipe for developing new research in the reader's own area. Two complete Java programs, one for the discussion Monte Carlo of 4^He clusters on a graphite surface and the other for the path-integral Monte Carlo of cold atoms in a potential trap, are ready for download and adoption.

The present theme concerns the forces of nature, and what investigations of these forces can tell us about the world we see about us. The story of these forces is long and complex, and contains many episodes that are not atypical of the bulk of scientific research, which could have achieved greater acclaim 'if only...'. The intention of this book is to introduce ideas of how the visible world, and those parts of it that we cannot observe, either because they are too small or too large for our scale of perception, can be understood by consideration of only a few fundamental forces. The subject in these pages will be the authority of the commonly termed, laws of physics, which arise from the forces of nature, and the corresponding constants of nature (for example, the speed of light, c, the charge of the electron, e, or the mass of the electron, me).

An Introduction to the Gas Phase is adapted from a set of lecture notes for a core first year lecture course in physical chemistry taught at the University of Oxford. The book is intended to give a relatively concise introduction to the gas phase at a level suitable for any undergraduate scientist. After defining the gas phase, properties of gases such as temperature, pressure, and volume are discussed. The relationships between these properties are explained at a molecular level, and simple models are introduced that allow the various gas laws to be derived from first principles. Finally, the collisional behavior of gases is used to explain a number of gas-phase phenomena, such as effusion, diffusion, and thermal conductivity.