Физика
Различные книги в жанре ФизикаPhotomedicine and Stem Cells
Janus, the ancient Roman god depicted with two faces is an appropriate metaphor for light therapy. In the right photodynamic therapy conditions, light is able to kill nearly anything that is living such as cancers, microorganisms, parasites, and more. On the opposite face, light of the correct wavelength and proper dose (photobiomodulation) can heal, regenerate, protect, revitalize and restore any kind of dead, damaged, stressed, dying, degenerating cells, tissue, or organ system. This book discusses both sides of Janus' face in regards to light therapy.
Detecting the Stochastic Gravitational-Wave Background
The stochastic gravitational-wave background (SGWB) is by far the most difficult source of gravitational radiation detect. At the same time, it is the most interesting and intriguing one. This book describes the initial detection of the SGWB and describes the underlying mathematics behind one of the most amazing discoveries of the 21st century. On the experimental side it would mean that interferometric gravitational wave detectors work even better than expected. On the observational side, such a detection could give us information about the very early Universe, information that could not be obtained otherwise. Even negative results and improved upper bounds could put constraints on many cosmological and particle physics models.
Origins of Life
Origins of Life: A Cosmic Perspective presents an overview of the concepts, methods, and theories of astrobiology and origins of life research while presenting a summary of the latest findings. The book provides insight into the environments and processes that gave birth to life on our planet, which naturally informs our assessment of the probability that has arisen (or will arise) elsewhere. In addition, the book encourages readers to go beyond basic concepts, to explore topics in greater depth, and to engage in lively discussions. The text is intended to be suitable for mid- and upper-level undergraduates and beginning graduate students and more generally as an introduction and overview for researchers and general readers seeking to follow current developments in this interdisciplinary field. Readers are assumed to have a basic grounding in the relevant sciences, but prior specialized knowledge is not required. Each chapter concludes with a list of questions and discussion topics as well as suggestions for further reading. Some questions can be answered with reference to material in the text, but others require further reading and some have no known answers. The intention is to encourage readers to go beyond basic concepts, to explore topics in greater depth, and, in a classroom setting, to engage in lively discussions with class members.
Halo Nuclei
While neutron halos were discovered 30 years ago, this is the first book written on the subject of this exotic form of nuclei that typically contain many more neutrons than stable isotopes of those elements. It provides an introductory description of the halo and outlines the discovery and evidence for its existence. It also discusses different theoretical models of the halo's structure as well as models and techniques in reaction theory that have allowed us to study the halo. This is written at a level accessible to graduate students starting a PhD in nuclear physics. Halo nuclei are an exotic form of atomic nuclei that contain typically many more neutrons than stable isotopes of those elements. To give you a famous example, an atom of the element lithium has three electrons orbiting a nucleus with three protons and, usually, either 3 or 4 neutrons. The difference in the number of neutrons gives us two different isotopes of lithium, Li6 and Li7. But if you keep adding neutrons to the nucleus you will eventually reach Li11, with still 3 protons (that means it's lithium) but with 8 neutrons. This nucleus is so neutron-rich that the last two are very weakly bound to the rest of the nucleus (a Li9 core). What happens is a quantum mechanical effect: the two outer neutrons float around beyond the rest of the nuclear core at a distance that is beyond the range of the force that is holding them to the core. This is utterly counterintuitive. It means the nucleus looks like a core plus extended diffuse cloud of neutron probability: the halo. The author of the book, Jim Al-Khalili, is a theoretician who published some of the key papers on the structure of the halo in the mid and late 90s and was the first to determine its true size. This monograph is based on review articles he has written on the mathematical models used to determine the halo structure and the reactions used to model that structure.
The Tai Chi in Star Formation
Tai Chi, a Chinese martial art developed based on the laws of nature, emphasises how 'to conquer the unyielding with the yielding.' The recent observation of star formation shows that stars result from the interaction between gravity, turbulence and magnetic fields. This interaction again follows the natural rules that inspired Tai Chi. For example, if self-gravity is the force that dominates, the molecular cloud will collapse isotropically, which compresses magnetic field lines. The density of the yielding field lines increases until magnetic pressure reaches the critical value to support the cloud against the gravitational force in directions perpendicular to the field lines (Lorentz force). Then gravity gives way to Lorentz force, accumulating gas only along the field lines till the gas density achieves the critical value to again compress the field lines. The Tai Chi goes on in a self similar way.
Essential Mathematics for the Physical Sciences, Volume 1
Physics is expressed in the language of mathematics; it is deeply ingrained in how physics is taught and how it's practiced. A study of the mathematics used in science is thus asound intellectual investment for training as scientists and engineers. This first volume of two is centered on methods of solving partial differential equations (PDEs) and the special functions introduced. Solving PDEs can't be done, however, outside of the context in which they apply to physical systems. The solutions to PDEs must conform to boundary conditions, a set of additional constraints in space or time to be satisfied at the boundaries of the system, that small part of the universe under study. The first volume is devoted to homogeneous boundary-value problems (BVPs), homogeneous implying a system lacking a forcing function, or source function. The second volume takes up (in addition to other topics) inhomogeneous problems where, in addition to the intrinsic PDE governing a physical field, source functions are an essential part of the system. This text is based on a course offered at the Naval Postgraduate School (NPS) and while produced for NPS needs, it will serve other universities well. It is based on the assumption that it follows a math review course, and was designed to coincide with the second quarter of student study, which is dominated by BVPs but also requires an understanding of special functions and Fourier analysis.
Crystal Engineering
There are more than 20 million chemicals in the literature, with new materials being synthesized each week. Most of these molecules are stable, and the 3-dimensional arrangement of the atoms in the molecules, in the various solids may be determined by routine x-ray crystallography. When this is done, it is found that this vast range of molecules, with varying sizes and shapes can be accommodated by only a handful of solid structures. This limited number of architectures for the packing of molecules of all shapes and sizes, to maximize attractive intermolecular forces and minimizing repulsive intermolecular forces, allows us to develop simple models of what holds the molecules together in the solid. In this volume we look at the origin of the molecular architecture of crystals; a topic that is becoming increasingly important and is often termed, crystal engineering. Such studies are a means of predicting crystal structures, and of designing crystals with particular properties by manipulating the structure and interaction of large molecules. That is, creating new crystal architectures with desired physical characteristics in which the molecules pack together in particular architectures; a subject of particular interest to the pharmaceutical industry.
Modeling Self-Heating Effects in Nanoscale Devices
It is generally acknowledged that modeling and simulation are preferred alternatives to trial and error approaches to semiconductor fabrication in the present environment, where the cost of process runs and associated mask sets is increasing exponentially with successive technology nodes. Hence, accurate physical device simulation tools are essential to accurately predict device and circuit performance. Accurate thermal modelling and the design of microelectronic devices and thin film structures at the micro- and nanoscales poses a challenge to electrical engineers who are less familiar with the basic concepts and ideas in sub-continuum heat transport. This book aims to bridge that gap. Efficient heat removal methods are necessary to increase device performance and device reliability. The authors provide readers with a combination of nanoscale experimental techniques and accurate modelling methods that must be employed in order to determine a device's temperature profile.
Semiconductor Integrated Optics for Switching Light
This book covers the technology of switching or modulating light in semiconductor optical waveguides. Currently a key function for optical communications systems is the conversion of data from an electrical signal to an optical signal for transmission in very low loss optical fibres and the converse process of optical to electrical conversion the O/E/O data conversion. This conversion between electronic and photonic signals imposes an energy consumption overhead on optical communication systems. So many research workers have been attracted to ultrafast all-optical switching of data in different formats. As a way of introduction to all-optical switching in semiconductor waveguides the book covers the electro-optic effect, electroabsorption and electrorefraction; effects that can be used in semiconductor optical modulation devices. But the book focuses on all-optical switching using second and third order optical nonlinearities in AlGaAs optical waveguides. It covers a variety of device configurations including integrated nonlinear couplers and Mach-Zehnder interferometers. Further, it provides design software in suit of Mathematica notebooks that can be used to explore the device design.
Spiral Structure in Galaxies
How does it happen that billions of stars can cooperate to produce the beautiful spirals that characterize so many galaxies, including ours? This book reviews the history behind the discovery of spiral galaxies and the problems faced when trying to explain the existence of spiral structure within them. In the book, subjects such as galaxy morphology and structure are addressed as well as several models for spiral structure. The evidence in favor or against these models is discussed. The book ends by discussing how spiral structure can be used as a proxy for other properties of spiral galaxies, such as their dark matter content and their central supermassive black hole masses, and why this is important.