The authors introduce and study the class of groups graded by root systems. They prove that if is an irreducible classical root system of rank and is a group graded by , then under certain natural conditions on the grading, the union of the root subgroups is a Kazhdan subset of . As the main application of this theorem the authors prove that for any reduced irreducible classical root system of rank and a finitely generated commutative ring with , the Steinberg group and the elementary Chevalley group have property . They also show that there exists a group with property which maps onto all finite simple groups of Lie type and rank , thereby providing a “unified” proof of expansion in these groups.
The authors introduce and study the class of groups graded by root systems. They prove that if is an irreducible classical root system of rank and is a group graded by , then under certain natural conditions on the grading, the union of the root subgroups is a Kazhdan subset of . As the main application of this theorem the authors prove that for any reduced irreducible classical root system of rank and a finitely generated commutative ring with , the Steinberg group and the elementary Chevalley group have property . They also show that there exists a group with property which maps onto all finite simple groups of Lie type and rank , thereby providing a “unified” proof of expansion in these groups.
This monograph describes mathematical models that enable prediction of phase compositions for various technological processes, as developed on the base of a complex physico-chemical analysis of reaction. It studies thermodynamics and kinetics of specific stages of complex pyrometallurgical processes involving boron, carbon, sulfur, tungsten, phosphorus, and many more, as well as their exposure to all sorts of factors. First and foremost, this enables to optimize processes and technologies at the stage of design, while traditional empirical means of development of new technologies are basically incapable of providing an optimal solution. Simulation results of metals and alloys production, welding and coating technologies allow obtaining materials with pre-given composition, structure and properties in a cost-saving and conscious manner. Moreover, a so-called "inverse problem", i.e., selecting source materials which would ensure the required results, cannot be solved by any other means.
This book features the refereed proceedings of the 2nd International Symposium on Computer Science in Russia held in September 2007. The 35 papers cover theory track deals with algorithms, protocols, and data structures; complexity and cryptography; formal languages, automata and their applications to computer science; computational models and concepts; proof theory; and applications of logic to computer science. Many applications are presented.
This second edition features new chapters highlighting advances in our understanding of the behavior and properties of scintillators, and the discovery of new families of materials with light yield and excellent energy resolution very close to the theoretical limit. The book focuses on the discovery of next-generation scintillation materials and on a deeper understanding of fundamental processes. Such novel materials with high light yield as well as significant advances in crystal engineering offer exciting new perspectives. Most promising is the application of scintillators for precise time tagging of events, at the level of 100 ps or higher, heralding a new era in medical applications and particle physics. Since the discovery of the Higgs Boson with a clear signature in the lead tungstate scintillating blocks of the CMS Electromagnetic Calorimeter detector, the current trend in particle physics is toward very high luminosity colliders, in which timing performance will ultimately be essential to mitigating pile-up problems. New and extremely fast light production mechanisms based on Hot-Intraband-Luminescence as well as quantum confinement are exploited for this purpose. Breakthroughs such as crystal engineering by means of co-doping procedures and selection of cations with small nuclear fragmentation cross-sections will also pave the way for the development of more advanced and radiation-hard materials. Similar innovations are expected in medical imaging, nuclear physics ecology, homeland security, space instrumentation and industrial applications. This second edition also reviews modern trends in our understanding and the engineering of scintillation materials. Readers will find new and updated references and information, as well as new concepts and inspirations to implement in their own research and engineering endeavors.
Each year a large number of first rate articles on the physics and technology of semiconductor devices, written by Soviet experts in the field, are published. However, due to the lack of exchange and personal contact, most of these, unfortunately, are neglected by many scientists from the United States, Japan as well as Western Europe. Consequently, many important developments in semiconductor physics are missed by the Western world.This book is a serious attempt to bridge the gap between the Soviet and Western scientific communities. Most of all, it is an effort towards facilitating the communication and sharing of knowledge amongst people from different parts of the world. Ultimately, the aim is to contribute towards the building of a better world for all ? one where the knowledge of advanced technology and scientific discoveries is used to improve the quality of life and not the pursuit of selfish mutually destructive behavior. For those in the field who wish to partake in this exchange of knowledge and as a gesture of support for their Soviet counterparts, the reading of this book provides the first step.
The adverse consequences of pollution impact on terrestrial ecosystems have been under careful investigation since the beginning of the twentieth century. Several thousand case studies have documented the biotic effects occurring in contaminated areas. However, after more than a century of research, ecologists are still far from understanding the effects of pollution on biota. Only a few generalisations have been made on the basis of extensive monitoring programs and numerous expe- ments with industrial contaminants. The need to reveal general patterns in the responses of terrestrial biota to ind- trial pollution and to identify the sources of variation in these responses became obvious more than a decade ago. At about that time, our team initiated a quanti- tive research synthesis of the biotic effects caused by industrial pollution, based on 1 a meta-analysis of published data. All meta-analyses conducted so far (covering diversity and abundance of soil microfungi, diversity of vascular plants, diversity and abundance of terrestrial arthropods, and plant growth and reproduction) c- sistently showed high heterogeneity in the responses of terrestrial biota to industrial pollution. At the same time, they demonstrated an unexpected shortage of infor- tion suitable for meta-analyses, as well as a considerable influence of methodology of primary studies on the outcome of the research syntheses. To overcome the identified problems, we designed a comparative study, the results of which are reported in this book.
Available for the first time in English, this two-volume course on theoretical and applied mechanics has been honed over decades by leading scientists and teachers, and is a primary teaching resource for engineering and maths students at St. Petersburg University. The course addresses classical branches of theoretical mechanics (Vol. 1), along with a wide range of advanced topics, special problems and applications (Vol. 2). Among the special applications addressed in this second volume are: stability of motion, nonlinear oscillations, dynamics and statics of the Stewart platform, mechanics under random forces, elements of control theory, relations between nonholonomic mechanics and the control theory, vibration and autobalancing of rotor systems, physical theory of impact, statics and dynamics of a thin rod. This textbook is aimed at students in mathematics and mechanics and at post-graduates and researchers in analytical mechanics.
Secrets of the Solovetsky Labyrinths: Who? Why? When? By: Vladmir Tolkachev and Mikhail Tolkachev Looking back on the “golden” days of yearly trips to the Solovki, Vladmir and Mikhail Tolkachev have expressed their nostalgia for these amazing places of the White Sea Region in this book, which reveals the secrets of stone labyrinths of the Solvetsky Archipelago. “There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy.” W. Shakespeare, Hamlet
As the basis for this book, the authors have analyzed more than 100,000 ultrasound examinations performed between 1995 and 2008 in patients with thyroid and parathyroid disease, as well as many thousands of diagnostic and therapeutic ultrasound-guided minimally invasive procedures. The opening chapters include discussion of current ultrasound techniques, pitfalls, and ultrasound examination of the thyroid in children. Detailed attention is then devoted to findings in the normal thyroid and in the presence of diffuse and focal changes. Further chapters focus on such topics as the role of ultrasound after thyroid surgery and ultrasound diagnosis of parathyroid disease, recurrent goiter, and neck masses. Ultrasound-guided minimally invasive techniques, such as fine-needle aspiration biopsy and percutaneous laser ablation, are considered in depth. This up-to-date and richly illustrated book will interest and assist specialists in ultrasound diagnostics, radiologists, endocrinologists, and neck surgeons.
A general approach to the derivation of equations of motion of as holonomic, as nonholonomic systems with the constraints of any order is suggested. The system of equations of motion in the generalized coordinates is regarded as a one vector relation, represented in a space tangential to a manifold of all possible positions of system at given instant. The tangential space is partitioned by the equations of constraints into two orthogonal subspaces. In one of them for the constraints up to the second order, the motion low is given by the equations of constraints and in the other one for ideal constraints, it is described by the vector equation without reactions of connections. In the whole space the motion low involves Lagrangian multipliers. It is shown that for the holonomic and nonholonomic constraints up to the second order, these multipliers can be found as the function of time, positions of system, and its velocities. The application of Lagrangian multipliers for holonomic systems permits us to construct a new method for determining the eigenfrequencies and eigenforms of oscillations of elastic systems and also to suggest a special form of equations for describing the system of motion of rigid bodies. The nonholonomic constraints, the order of which is greater than two, are regarded as programming constraints such that their validity is provided due to the existence of generalized control forces, which are determined as the functions of time. The closed system of differential equations, which makes it possible to find as these control forces, as the generalized Lagrange coordinates, is compound. The theory suggested is illustrated by the examples of a spacecraft motion. The book is primarily addressed to specialists in analytic mechanics.
Thank you for visiting our website. Would you like to provide feedback on how we could improve your experience?
This site does not use any third party cookies with one exception — it uses cookies from Google to deliver its services and to analyze traffic.Learn More.