The origins and significance of electron density in the chemical, biological, and materials sciences Electron density is one of the fundamental concepts underlying modern chemistry and one of the key determinants of molecular structure and stability. It is also the basic variable of density functional theory, which has made possible, in recent years, the application of the mathematical theory of quantum physics to chemical and biological systems. With an equal emphasis on computational and philosophical questions, A Matter of Density: Exploring the Electron Density Concept in the Chemical, Biological, and Materials Sciences addresses the foundations, analysis, and applications of this pivotal chemical concept. The first part of the book presents a coherent and logically connected treatment of the theoretical foundations of the electron density concept. Discussion includes the use of probabilities in statistical physics; the origins of quantum mechanics; the philosophical questions at the heart of quantum theory, like quantum entanglement; and methods for the experimental determination of electron density distributions. The remainder of the book deals with applications of the electron density concept in the chemical, biological, and materials sciences. Contributors offer insights on how a deep understanding of the origins of chemical reactivity can be gleaned from the concepts of density functional theory. Also discussed are the applications of electron density in molecular similarity analysis and electron density-derived molecular descriptors, such as electrostatic potentials and local ionization energies. This section concludes with some applications of modern density functional theory to surfaces and interfaces. An essential reference for students as well as quantum and computational chemists, physical chemists, and physicists, this book offers an unparalleled look at the development of the concept of electron density from its inception to its role in density functional theory, which led to the 1998 Nobel Prize in Chemistry.
Using the concept of three-electron bond we can represent the actual electron structure of benzene and other molecules, explain specificity of the aromatic bond and calculate the delocalization energy. The aromatic bond is a three-electron bond in flat cyclic systems with a specific interaction of electrons through the cycle. In benzene formed a new type of chemical bonds – an aromatic bond, which has a multiplicity of more than 1.5 (1.66) http://vixra.org/author/bezverkhniy_volodymyr_dmytrovych
Winner, 2013 PROSE Award, Engineering and Technology Concise, high quality and comparative overview of state-of-the-art electron device development, manufacturing technologies and applications Guide to State-of-the-Art Electron Devices marks the 60th anniversary of the IRE electron devices committee and the 35th anniversary of the IEEE Electron Devices Society, as such it defines the state-of-the-art of electron devices, as well as future directions across the entire field. Spans full range of electron device types such as photovoltaic devices, semiconductor manufacturing and VLSI technology and circuits, covered by IEEE Electron and Devices Society Contributed by internationally respected members of the electron devices community A timely desk reference with fully-integrated colour and a unique lay-out with sidebars to highlight the key terms Discusses the historical developments and speculates on future trends to give a more rounded picture of the topics covered A valuable resource R&D managers; engineers in the semiconductor industry; applied scientists; circuit designers; Masters students in power electronics; and members of the IEEE Electron Device Society.
Neutron and synchrotron facilities, which are beyond the scale of the laboratory, and supported on a national level in countries throughout the world. These tools for probing micro- and nano-structure research and on fast dynamics research of atomic location in materials have been key in the development of new polymer-based materials. Different from several existing professional books on neutron science, this book focuses on theory, instrumentation, an applications. The book is divided into five parts: Part 1 describes the underlying theory of neutron scattering. Part 2 describes the various instruments that exist and the various techniques used to achieve neutron scattering or bombardment. Part 3 discusses data treatment and simulation methods as well as how to assess the environment of the sample (temperature, pressure, shear, and external fields). Part 4 addresses the myriad applications of small and large molecules, biomolecules, and gels. Part 5 describes the various global neutron sources that exist and provides an overview of the different reactors.
These notes are a result of a series of lectures given to the MS and PhD students of the Department of Physics, Moscow State Pedagogical University. They deal with the subject of electron-phonon interaction in pure threedimensional metals. The goal was to show how one could calculate the temperature dependence of the electron-phonon-interaction time from first principles within a simple model. Students wishing to expand their knowledge of the subject of condensed matter are invited to study any book on solid-state physics (for example by J.M. Ziman, or N.W. Ashcroft and N.D. Mermin.
The Early Earth: Accretion and Differentiation provides a multidisciplinary overview of the state of the art in understanding the formation and primordial evolution of the Earth. The fundamental structure of the Earth as we know it today was inherited from the initial conditions 4.56 billion years ago as a consequence of planetesimal accretion, large impacts among planetary objects, and planetary-scale differentiation. The evolution of the Earth from a molten ball of metal and magma to the tectonically active, dynamic, habitable planet that we know today is unique among the terrestrial planets, and understanding the earliest processes that led to Earth’s current state is the essence of this volume. Important results have emerged from a wide range of disciplines including cosmochemistry, geochemistry, experimental petrology, experimental and theoretical mineral physics and geodynamics. The topics in this volume include: Condensation of primitive objects in the solar nebula, planetary building blocks Early and late accretion and planetary dynamic modeling Primordial differentiation, core formation, Magma Ocean evolution and crystallization This volume will be a valuable resource for graduate students, academics, and researchers in the fields of geophysics, geochemistry, cosmochemistry, and planetary science.
Тип нож Тип реза прямой Для моделей Fellowes Neutron, Proton, Electron
Introducing up-to-date coverage of research in electron field emission from nanostructures, Vacuum Nanoelectronic Devices outlines the physics of quantum nanostructures, basic principles of electron field emission, and vacuum nanoelectronic devices operation, and offers as insight state-of-the-art and future researches and developments. This book also evaluates the results of research and development of novel quantum electron sources that will determine the future development of vacuum nanoelectronics. Further to this, the influence of quantum mechanical effects on high frequency vacuum nanoelectronic devices is also assessed. Key features: • In-depth description and analysis of the fundamentals of Quantum Electron effects in novel electron sources. • Comprehensive and up-to-date summary of the physics and technologies for THz sources for students of physical and engineering specialties and electronics engineers. • Unique coverage of quantum physical results for electron-field emission and novel electron sources with quantum effects, relevant for many applications such as electron microscopy, electron lithography, imaging and communication systems and signal processing. • New approaches for realization of electron sources with required and optimal parameters in electronic devices such as vacuum micro and nanoelectronics. This is an essential reference for researchers working in terahertz technology wanting to expand their knowledge of electron beam generation in vacuum and electron source quantum concepts. It is also valuable to advanced students in electronics engineering and physics who want to deepen their understanding of this topic. Ultimately, the progress of the quantum nanostructure theory and technology will promote the progress and development of electron sources as main part of vacuum macro-, micro- and nanoelectronics.
Тип марзан Для моделей А4 Neutron, Proton, Electron
Набор предназначен для замены марзанов на дисковых резаках формата А4: Neutron A4, Neutron A4 Plus, Proton A4, Electron A4. Для моделей: Neutron A4, Neutron A4 Plus, Proton A4, Electron A4
High blood pressure is a common chronic medical problem encountered in primary care, yet it is commonly under diagnosed. ABC of Hypertension is a long established, practical guide to the investigation, treatment and management of hypertensive patients. This sixth edition: Provides practical guidance on measurement of blood pressure and the investigation and management of hypertensive patients Explains new developments in measurement and automated measurement of blood pressure and Updates coverage on treatment of the elderly and explains of the implications of recent trials Incorporates current British Hypertension Society and NICE guidelines
A practical, in-depth description of the physics behind electron emission physics and its usage in science and technology Electron emission is both a fundamental phenomenon and an enabling component that lies at the very heart of modern science and technology. Written by a recognized authority in the field, with expertise in both electron emission physics and electron beam physics, An Introduction to Electron Emission provides an in-depth look at the physics behind thermal, field, photo, and secondary electron emission mechanisms, how that physics affects the beams that result through space charge and emittance growth, and explores the physics behind their utilization in an array of applications. The book addresses mathematical and numerical methods underlying electron emission, describing where the equations originated, how they are related, and how they may be correctly used to model actual sources for devices using electron beams. Writing for the beam physics and solid state communities, the author explores applications of electron emission methodology to solid state, statistical, and quantum mechanical ideas and concepts related to simulations of electron beams to condensed matter, solid state and fabrication communities. Provides an extensive description of the physics behind four electron emission mechanisms—field, photo, and secondary, and how that physics relates to factors such as space charge and emittance that affect electron beams. Introduces readers to mathematical and numerical methods, their origins, and how they may be correctly used to model actual sources for devices using electron beams Demonstrates applications of electron methodology as well as quantum mechanical concepts related to simulations of electron beams to solid state design and manufacture Designed to function as both a graduate-level text and a reference for research professionals Introduction to the Physics of Electron Emission is a valuable learning tool for postgraduates studying quantum mechanics, statistical mechanics, solid state physics, electron transport, and beam physics. It is also an indispensable resource for academic researchers and professionals who use electron sources, model electron emission, develop cathode technologies, or utilize electron beams.
This book presents a comprehensive overview of the first longitudinal study of the downstream response of a major river to the establishment of a large hydropower facility and dams. Peace River, a northward flowing boreal river in northwestern Canada was dammed in 1967 and the book describes the morphological response of the 1200 km downstream channel and the response of riparian vegetation to the change in flow regime over the first forty years of regulated flows. Beginning with a description of the effect of regulation on the flow and sediment regimes of the river, the book proceeds to study changes in downstream channel geometry on the main stem, on the lowermost course of tributaries, and on the hydraulic geometry, the overall morphology of the channel, and riparian vegetation succession. The river is subject to annual freeze-up and break-up, so a chapter is devoted to the ice regime of the river. A chapter compares the effects of two extraordinary post-regulation flood events. The penultimate chapter presents a prediction of the ultimate equilibrium form of the regulated river based on rational regime theory. An online database of all the main observations will provide invaluable material for advanced students of river hydraulics and geomorphology. This book carefully brings together a range of studies that have been previously inaccessible providing a rare and comprehensive analysis of the effects of a big dam on a river, a river that itself represents an example of the kind of system that is likely to receive considerable attention in the future from dam engineers and environmentalists. • An invaluable reference to river scientists, hydroelectric power developers, engineers and environmentalists • Focus on a northward flowing boreal river, a type that holds most of the remaining hydroelectric power potential in the Northern Hemisphere • Exceptional separation of water and sediment sources, permitting study of the isolated effect of manipulating one of the two major governing conditions of river processes and form • Unique example of water regulation and both natural and engineered flood flows • Detailed study of both morphological changes of the channel and of the riparian vegetation • Online data supplement including major data tables and numerous maps. Details of the main observations and provides material for problem study by advanced students of river hydraulics and geomorphology are provided
In the year 2100, the invention of the Electron Pump - an apparently inexhaustible supply of free energy - has enabled humanity to devote its time and energies to more than the struggle for survival, finally breaking free of the Earth. But the Electron Pump works by exchanging materials with a parallel universe, and such unbalancing of the cosmos has consequences. Humans and aliens alike must race to prevent a vast nuclear explosion in the heart of the Sun - and the vaporisation of the Earth exactly eight minutes later...
A guide to analyzing the structures and properties of organic molecules Until recently, the study of organic molecules has traveled down two disparate intellectual paths—the experimental, or physical, method and the computational, or theoretical, method. Working somewhat independently of each other, these disciplines have guided research for decades, but they are now being combined efficiently into one unified strategy. Molecular Structure delivers the essential fundamentals on both the experimental and computational methods, then goes further to show how these approaches can join forces to produce more effective analysis of the structure and properties of organic compounds by: Looking at experimental structures: electron, neutron, X-ray diffraction, and microwave spectroscopy as well as computational structures: ab initio, semi-empirical molecular orbital, and molecular mechanics calculations Discussing various electronic effects, particularly stereoelectronic effects, including hyperconjugation, negative hyperconjugation, the Bohlmann and anomeric effects, and how and why these cause changes in structures and properties of molecules Illustrating complex carbohydrate effects such as the gauche effect, the delta-two effect, and the external anomeric torsional effect Covering hydrogen bonding, the CH bond, and how energies, especially heats of formation, can be affected Using molecular mechanics to tie all of these things together in the familiar language of the organic chemist, valence bond pictures Authored by a founding father of computational chemistry, Molecular Structure broadens the scope of the subject by serving as a pioneering guide for workers in the fields of organic, biological, and computational chemistry, as they explore new possibilities to advance their discoveries. This work will also be of interest to many of those in tangential or dependent fields, including medicinal and pharmaceutical chemistry and pharmacology.
The effect of health on labor force participation is an established fact. This research hypothesizes the endogeneity of health stemming from the reverse effect, reporting bias and unobserved factors. The relationship between health and labor force participation of elderly Russians is modeled with simultaneous equations using data from World Health Organization Study on Global Ageing and Adult Health, Wave 1 (WHO SAGE, 2007–2010). A strong and non-linear effect of health on labor force participation is confirmed. Unlike for a complex health measure, endogeneity, confirmed by the correlation of unobserved shocks in the system of equations, is found for single-question health measures. The results show that the official retirement age has a moderate effect on labor force participation for women and a weaker or no effect for men. Nevertheless, the health of elderly Russians does not impose strong limitations on the increase of the retirement age.
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