موضوعات
آموزش و پرورش
ادبیات و زبان
پزشکی، دندانپزشکی و داروسازی
تاریخ و جغرافیا
داستان و رمان
دیگر
دین و فلسفه
روانشناسی
ریاضیات و آمار
سلامتی، تناسب اندام و رژیم غذایی
شیمی و پلیمر
علوم اجتماعی و حقوق
علوم زیستی و بیوتکنولوژی
فیزیک و نجوم
کامپیوتر و اینترنت
کتابهای کودکان و داستان
کسب و کار و اقتصاد
کشاورزی و دامپزشکی و غذا
معماری
مهندسی و فناوری
هنر و تئاتر
محصولات
Quantum thermodynamics: emergence of thermodynamic behavior within composite quantum systems - Original PDF
نویسندگان: خلاصه: This extended tutorial essay views thermodynamics as an incomplete description of quantum systems with many degrees of freedom. The main goal is to show that the approach to equilibrium - with equilibrium characterized by maximum ignorance about the open system of interest - neither requires that many particles nor is it a precise way of partitioning relevant for the salient features of equilibrium and equilibration. Moreover it is indeed quantum effects that are at work in bringing about universal thermodynamic behaviour of modestly sized open systems. Von Neumann`s concept of entropy thus proves to be much more widely useful than something to be feared, and far beyond truly macroscopic systems in equilibrium.
Plasticity of Metals and Alloys - Original PDF
نویسندگان: خلاصه: In this title, the results of observations and investigations of a new phenomenon - changes in the macroscopic characteristics of the plastic deformation of metals and alloys at a superconducting transition - are systematised. In these works it is shown for the first time that the electronic drag of dislocations accompanying low-temperature deformation is effective. The main experimental features of the phenomenon - the dependences of the characteristics of the change in plasticity at a superconducting transition on the stress, deformation, temperature, deformation rate, and concentration of the alloying element in the superconductor - and results indicating a correlation between the characteristics of the effect and the superconducting properties are presented. Experiments clarifying the mechanisms of the phenomenon are analysed. A brief exposition of the theoretical investigations of the electronic drag of dislocations in metals in the normal and superconducting states and the influence of a superconducting transition on the plasticity is given. The theoretical results are compared with the experimental results. Examples of the application of the effect as a new method for investigating the physical mechanisms of low-temperature plastic deformation are presented. The applied aspects of the phenomenon are discussed separately.
High temperature strain of metals and alloys: physical fundamentals - Original PDF
نویسندگان: خلاصه: Creep and fatigue are the most prevalent causes of rupture in superalloys, which are important materials for industrial usage, e.g. in engines and turbine blades in aerospace or in energy producing industries. As temperature increases, atom mobility becomes appreciable, affecting a number of metal and alloy properties. It is thus vital to find new characterization methods that allow an understanding of the fundamental physics of creep in these materials as well as in pure metals. Here, the author shows how new in situ X-ray investigations and transmission electron microscope studies lead to novel explanations of high-temperature deformation and creep in pure metals, solid solutions and superalloys. This unique approach is the first to find unequivocal and quantitative expressions for the macroscopic deformation rate by means of three groups of parameters: substructural characteristics, physical material constants and external conditions. Creep strength of the studied up-to-date single crystal superalloys is greatly increased over conventional polycrystalline superalloys. From the contents: - Macroscopic characteristics of strain at high temperatures - Experimental equipment and technique of in situ X-ray investigations - Experimental data and structural parameters in deformed metals - Subboundaries as dislocation sources and obstacles - The physical mechanism of creep and the quantitative structural model - Simulation of the parameters evolution - System of differential equations - High-temperature deformation of industrial superalloys - Single crystals of superalloys - Effect of composition, orientation and temperature on properties - Creep of some refractory metals For materials scientists, solid state physicists, solid state chemists, researchers and practitioners from industry sectors including metallurgical, mechanical, chemical and structural engineers.
Phase Transformations of Elements Under High Pressure - Original PDF
نویسندگان: خلاصه: The study of transformations of materials under high pressures promises to yield modifications with important applications in materials science and other fields including, by way of example, the dense metallic modification of hydrogen possessing extremely high superconducting properties. This work presents recent theoretical and experimental information gathered on phase diagrams of 96 elements. Data is presented on first- and second-phase transitions, melting lines, crystal structures of the stable and metastable phases, important phase properties such as the Curie and Neel temperature, and the superconducting temperature. Information is provided on elements' liquid state, amorphization, and metallization. Temperature-pressure diagrams are given for most of the elements.
Nanocrystalline Aluminum Alloys - Original PDF
نویسندگان: خلاصه: In order for a material to be defined nanocrystalline the size of its grains must be of the order of less than 100 nm. Such materials can be constituted by one or more phases distributed in one, two, or three dimensions. Examples are nanowires, layers either deposited on top of a substrate as coatings or stacked in suitable sequences, and bulk objects. If the material is fully made of nanograins the number density of crystals scales with their size (e.g., it can range from 1025 to 1021 m−3 for sizes of 5 and 100 nm respectively).
Mossbauer analysis of the atomic and magnetic structure of alloys - Original PDF
نویسندگان: خلاصه: The monograph indicates the key problems that have to be solved for the further development of the Mossbauer methods for analysis of the nuclear and magnetic structure of alloys, and offer solution variants for some of these problems based on the generalised results of a wide range of theoretical and experimental investigations, including original work by the author of the book and his colleagues.
Fundamentals of Discrete Element Methods for Rock Engineering - Original PDF
نویسندگان: خلاصه: PREFACE This book is a summary of our collaborative teaching and research efforts over the last two decades relating to the subject of discrete element methods (DEM) and its applications to rock mechanics and rock engineering. We have not intended this book to be a thorough presentation of the most current cutting- edge research subjects in the fields of DEM and its applications in geosciences and geoengineering – because the advances are occurring too rapidly. Instead we present some fundamental concepts behind the basic theories and tools of DEM, its historical development and its wide scope of applications in geology, geophysics and rock engineering. We hope that, with this moderate ambition, it may be more helpful and useful for a larger number of practicing engineers, students and researchers alike and serve as a starting platform for more advanced and in-depth further studies. Unlike almost all books available on the general subject of DEM, this book includes coverage of both explicit and implicit DEM approaches, namely the distinct element methods and discontinuous deforma- tion analysis (DDA) for both rigid and deformable blocks and particle systems, and also the discrete fracture network (DFN) approach for fluid flow simulations. Actually the latter is also a discrete approach of importance for rock mechanics and rock engineering. In addition, brief introductions to some alternative approaches are also provided, such as percolation theory and Cosserat micro-mechanics equivalence to particle systems, which often appear hand in hand with the DEM in the literature. We provide a presentation of the fundamentals of the governing equations of the discrete systems concerning motion, deformation, fluid flow and heat transfer, to an extent that is currently considered in some available DEM codes. Special attention is given to constitutive models of rock fractures and fracture system characterization methods. These two issues are the basic building blocks of DEM and also have the most significant impacts on the performance and uncertainty of the DEM models. The DEMs were pioneered and continuously developed by Dr P. A. Cundall, the creator of the distinct element methods, and Dr Genhua Shi, the creator of DDA, block theory and numerical manifold method. The authors learned DEM basics from them and received continuous inspirations and encour- agements. This book presents only some basics of the distinct element methods and discontinuous deformation analysis, only small parts of their outstanding contributions. The first author expresses his special gratitude to Professor Xuefu Yu in China, who led the author into the fields of rock mechanics and numerical modeling in late 1970s and provided continuous guidance and encouragements
High-energy ball milling Mechanochemical processing of nanopowders - Original PDF
نویسندگان: خلاصه: Nanotechnology is an area of science and technology where dimensions and toler- ances in the range of 0.1 nm to 100 nm play a critical role. Nanotechnology encom- passes precision engineering as well as electronics, electromechanical systems and mainstream biomedical applications in areas as diverse as gene therapy, drug deliv- ery and novel drug discovery techniques. Nanostructured materials present exciting opportunities for manipulating structure and properties at the nano scale and the ability to engineer novel structures at the molecular level has led to unprecedented opportunities for materials design. This new book provides detailed insights into the synthesis/structure and property relationships of nanostructured materials. This is a valuable book for materials scientists, mechanical and electronic engineers and medical researchers.
The Iron Oxides Structure, Properties, Reactions, Occurences and Uses - Original PDF
نویسندگان: خلاصه: Preface to the Second Edition Since this book first appeared, there have been hundreds of new publications on the subject of iron oxides. These have covered a wide range of disciplines including sur- face chemistry, the geosciences, mineralogy, environmental science and various branches of technology. In view of the amount of new material that is available, we decided, that once the copies of the first edition were exhausted, we would prepare a second edition that would incorporate the new developments. As before, our aim has been to bring all aspects of the information concerning iron oxides into a single, compact volume. All the chapters have been revised and up- dated and new figures and tables added. The book is structured according to topic with the same arrangement as in the first edition being followed. In view of the re- cent recognition of the impact iron oxides have on environmental processes, a chap- ter dealing with the environmental aspects of these compounds has been added. The book concludes with a considerably expanded bibliography. We hope that this new edition will continue to be of interest to all those research- ers who, in one way or another, are involved with iron oxides. Numerous persons and institutions from around the world again supplied data, figures, colour pictures and electron micrographs and technical help. These include Dr. H. Chr. Bartscherer (Mçnchen), Mr M. Burlot (Apt), Dr. R. Båumler and Dr. Be- cher (Freising), Mr H. Breuning (Stuttgart), Dr. J. M. Bigham (Columbus, USA), Dr. G. Buxbaum (Bayer), Dr. L. Carlson (Helsinki), Dr. R. A. Eggleton (Canberra), Dr. F. G. Ferris (Toronto), Dr. R. W. Fitzpatrick (Adelaide), Dr. D. Fortin (Ottawa), Dr. M. R. Fontes (Guatemala), Professor R. Giovanoli (Bern), Dr. G. Glasauer (Guelph), Dr. M. Hanslick (Mçnchen), Dr. P. Jaesche (Freising), Dr. A. A. Jones (Reading), Dr. R. C. Jones (Honolulu), Dr. D. E. Janney (Tempe), Dr. R. Loeppert (College Station), Professor S. Mann (Bristol), Dr. E. Murad (Marktredwitz), Dr. H. Maeda (Tsukuba), Professor A. Manceau (Grenoble), Professor E. Matijevic (Potsdam, USA), Mrs U. Maul (Freising), Dr. J. P. Muller (Paris), Muse National de Prhistoire (Les Eyzies, France), Mr R. Miehler (Mçnchen), Dr. T. Nagano (Naka), Dr. H. Naono (Uegahara), NASA (Houston), Professor A. Posner { (Perth), Mrs M. Sauvet (Apt), Dr. N. Sabil (Mçnchen), Dr. P. Schad (Freising), Dr. A. Schei- degger (Zçrich), Dr. T. Schwarz (Berlin), Dr. A. Scheinost (Zçrich), Dr. D. Schçler (Bremen), D. Schwertmann (Freising), Professor H. Stanjek (Aachen), Dr. P. Self (Adelaide), Professor T. Sugimoto (Sendai), Dr. K. Tazaki (Ishikawa), Dr. T. Tessie
Comminution 1994 Proceedings of the 8th European Symposium on Comminution and 50th Event of the European Federation of Chemical Engineering, May 17-19, 1994 Stockholm, Swede - PDF
نویسندگان: خلاصه: Particle arrangements and confinements can be classified in the four groups (1) single particle situation, (2) one-particle layer, (3) particle bed confined closely or widely, and (4) ideal particle bed. Any confinement influences the stress distribution inside the bed due to the wall friction, and a complex stress field arises. The size-reduction effect is represented with the fraction of broken particles, the breakage function and the specific surface increases. The breakage functions of the particle bed comminution display as truncated logarithmic normal distributions. The stressing intensity can be quantified by the pressure, the stress field characteristics or the energy absorption. Although the stress field situation can differ extremely, the overall energy absorption has been proven to represent the stressing intensity very well in respect to the size-reduction. The transition from a close to a moderately wide confinement does not affect the size-reduction strongly. Steel balls inserted in a particle bed improve the breakage of coarse particles at a low intensity level. This advantage fades with increasing intensity and decreasing particle size.آیا کتاب مورد نظر هنوز بر روی سایت قرار نگرفته است؟ جای نگرانی نیست! کافی است بر روی گزینه سفارش کتاب کلیک کرده و درخواست خود را ثبت کنید. در کمتر از چند ساعت کتاب شما را آماده خواهیم کرد.