IOP Concise Physics
Скачать книги из серии IOP Concise PhysicsSpin-Wave Theory and its Applications to Neutron Scattering and THz Spectroscopy
Two of the most powerful tools used to study magnetic materials are inelastic neutron scattering and THz spectroscopy. Because the measured spectra provide a dynamical fingerprint of a magnetic material, those tools enable scientists to unravel the structure of complex magnetic states and to determine the microcscopic interactions that produce them. This book discusses the experimental techniques of inleastic neutron scattering and THz spectroscopy and provides the theoretical tools required to analyze their measurements using spin-wave theory. For most materials, this analysis can resolve the microscopic magnetic interactions such as exchange, anisotropy, and Dzyaloshinskii-Moriya interactions. Assuming a background in elementary statistical mechanics and a familiarity with the quantized harmonic oscillator, this book presents a comprehensive review of spin-wave theory and its applications to both inelastic neutron scattering and THz spectroscopy. Spin-wave theory is used to study several model magnetic systems, including non-collinear magnets such as spirals and cycloids that are produced by geometric frustration, competing exchange interactions, or Dzyaloshinskii-Moriya interactions. Several case studies utilizing spin-wave theory to analyze inelastic neutron-scattering and THz spectroscopy measurements are presented. These include both single crystals and powders and both oxides and molecule-based magnets. In addition to sketching the numerical techniques used to fit dynamical spectra based on microscopic models, this book also contains over 70 exercises that can be performed by beginning graduate students.
The Physics of Destructive Earthquakes
This book is a concise introduction to the interactions between earthquakes and human-built structures (buildings, dams, bridges, power plants, pipelines and more). It focuses on the ways in which these interactions illustrate the application of basic physics principles and concepts, including inertia, force, shear, energy, acceleration, elasticity, friction and stability. It illustrates how conceptual and quantitative physics emerges in the day-to-day work of engineers, drawing from examples from regions and events which have experienced very violent earthquakes with massive loss of life and property. The authors of this book, a physics educator, a math educator, and a geotechnical engineer have set off on what might be considered a mining expedition; searching for ways in which introductory physics topics and methods can be better connected with careers of interest to non-physics majors. They selected «destructive earthquakes» as a place to begin because they are interesting and because future engineers represent a significant portion of the non-physics majors in introductory physics courses. Avoiding the extremes of treating applied physics either as a purely hands-on, conceptual experience or as a lengthy capstone project for learners who have become masters; the application in this book can be scattered throughout a broader physics course or individual learning experience.
Is It the 'Same' Result
Replication, the independent confirmation of experimental results and conclusions, is regarded as the «gold standard» in science. This book examines the question of successful or failed replications and demonstrates that that question is not always easy to answer. It presents clear examples of successful replications, the discoveries of the Higgs boson and of gravity waves. Failed replications include early experiments on the Fifth Force, a proposed modification of Newton's Law of universal gravitation, and the measurements of «G,» the constant in that law. Other case studies illustrate some of the difficulties and complexities in deciding whether a replication is successful or failed. It also discusses how that question has been answered. These studies include the «discovery» of the pentaquark in the early 2000s and the continuing search for neutrinoless double beta decay. It argues that although successful replication is the goal of scientific experimentation, it is not always easily achieved.
A Practical Introduction to Beam Physics and Particle Accelerators
This book provides a brief exposition of the principles of beam physics and particle accelerators with an emphasis on numerical examples employing readily available computer tools. However, it avoids detailed derivations, instead inviting the reader to use general high-end languages such as Mathcad and Matlab, as well as specialized particle accelerator codes (e.g. MAD, WinAgile, Elegant, and others) to explore the principles presented. This approach allows readers to readily identify relevant design parameters and their scaling. In addition, the computer input files can serve as templates that can be easily adapted to other related situations. The examples and computer exercises comprise basic lenses and deflectors, fringe fields, lattice and beam functions, synchrotron radiation, beam envelope matching, betatron resonances, and transverse and longitudinal emittance and space charge. The last chapter presents examples of two major types of particle accelerators: radio frequency linear accelerators (RF linacs) and storage rings. Lastly, the appendix gives readers a brief description of the computer tools employed and concise instructions for their installation and use in the most popular computer platforms (Windows, Macintosh and Ubuntu Linux). Hyperlinks to websites containing all relevant files are also included. An essential component of the book is its website (actually part of the author's website at the University of Maryland), which contains the files that reproduce results given in the text as well as additional material such as technical notes and movies.
Electrostatics at the Molecular Level
Electrostatic forces are essential for the hierarchical structure of matter: electrons are bound to the atomic nucleus by electrostatic forces; atoms carry (partial) charges and ions with opposite charges attract and form (chemical) bonds. Small residual electrostatic forces between molecules allow them to form macroscopic structures such as crystals. Electrostatic interactions explain pseudo-forces used in popular computer programs used to model properties of atoms, molecules, and proteins. By beginning with the basics and then diving deeper into the topic, this book aims to familiarize the reader with electrostatic forces at the atomic and molecular level.
Truth and Traceability in Physics and Metrology
Metrological data is known to be blurred by the imperfections of the measuring process. In retrospect, for about two centuries regular or constant errors were no focal point of experimental activities, only irregular or random error were. Today's notation of unknown systematic errors is in line with this. Confusingly enough, the worldwide practiced approach to belatedly admit those unknown systematic errors amounts to consider them as being random, too. This book discusses a new error concept dispensing with the common practice to randomize unknown systematic errors. Instead, unknown systematic errors will be treated as what they physically are- namely as constants being unknown with respect to magnitude and sign. The ideas considered in this book issue a proceeding steadily localizing the true values of the measurands and consequently traceability.
Fourier Transform and Its Applications Using Microsoft EXCEL®
This book demonstrates Microsoft EXCEL-based Fourier transform of selected physics examples. Spectral density of the auto-regression process is also described in relation to Fourier transform. Rather than offering rigorous mathematics, readers will «try and feel» Fourier transform for themselves through the examples. Readers can also acquire and analyze their own data following the step-by-step procedure explained in this book. A hands-on acoustic spectral analysis can be one of the ideal long-term student projects.
Disorder in Domain Theory
Domain theory, a subject that arose as a response to natural concerns in the semantics of computation, studies ordered sets which possess an unusual amount of mathematical structure. This book explores its connection with quantum information science and the concept that relates them: disorder. This is not a literary work. It can be argued that its subject, domain theory and quantum information science, does not even really exist, which makes the scope of this alleged 'work' irrelevant. BUT, it does have a purpose and to some extent, it can also be said to have a method. I leave the determination of both of those largely to you, the reader. Except to say, I am hoping to convince the uninitiated to take a look. A look at what? Twenty years ago, I failed to satisfactorily prove a claim that I still believe: that there is substantial domain theoretic structure in quantum mechanics and that we can learn a lot from it. One day it will be proven to the point that people will be comfortable dismissing it as a 'well-known' idea that many (possibly including themselves) had long suspected but simply never bothered to write down. They may even call it «obvious!» I will not bore you with a brief history lesson on why it is not obvious, except to say that we have never been interested in the difficulty of proving the claim only in establishing its validity. This book then documents various attempts on my part to do just that.
Outside the Research Lab, Volume 2
This book explores the physics and technology inherent to preserving and restoring old forms of transport as well as creating modern transport for today and for our future needs. This book provides readers with interesting insight into some of the diverse applications for physics outside of research laboratories. It also covers several different aspects of transport, ranging from the restoration of vintage buses to the materials used in the latest supercars.
Nonlinear Waves
The Boussinesq equation is the first model of surface waves in shallow water that considers the nonlinearity and the dispersion and their interaction as a reason for wave stability known as the Boussinesq paradigm. This balance bears solitary waves that behave like quasi-particles. At present, there are some Boussinesq-like equations. The prevalent part of the known analytical and numerical solutions, however, relates to the 1d case while for multidimensional cases, almost nothing is known so far. An exclusion is the solutions of the Kadomtsev-Petviashvili equation. The difficulties originate from the lack of known analytic initial conditions and the nonintegrability in the multidimensional case. Another problem is which kind of nonlinearity will keep the temporal stability of localized solutions. The system of coupled nonlinear Schroedinger equations known as well as the vector Schroedinger equation is a soliton supporting dynamical system. It is considered as a model of light propagation in Kerr isotropic media. Along with that, the phenomenology of the equation opens a prospect of investigating the quasi-particle behavior of the interacting solitons. The initial polarization of the vector Schroedinger equation and its evolution evolves from the vector nature of the model. The existence of exact (analytical) solutions usually is rendered to simpler models, while for the vector Schroedinger equation such solutions are not known. This determines the role of the numerical schemes and approaches. The vector Schroedinger equation is a spring-board for combining the reduced integrability and conservation laws in a discrete level. The experimental observation and measurement of ultrashort pulses in waveguides is a hard job and this is the reason and stimulus to create mathematical models for computer simulations, as well as reliable algorithms for treating the governing equations. Along with the nonintegrability, one more problem appears here – the multidimensionality and necessity to split and linearize the operators in the appropriate way.