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Books > Science & Mathematics > Physics > Atomic & molecular physics
The broad field of conformational motion disorder in crystals is
described with particular attention to the separation from the well
known mesophases of liquid crystals and plastic crystals.
Structure, thermodynamics and motion of a larger number of small
and large molecules are discussed. Of special interest are the
borderlines between smectic and high viscosity liquid crystals and
condis crystals and between plastic crystals and condis crystals as
complicated by pseudorotation, jumping between symmetry-related
states and hindered rotation. This paper illustrates the wide
distribution of conformational disorder in nature. Condis crystals
and glasses ("Con"formational "Dis"order) can be found in small and
large molecule systems made of organic, inorganic and biological
compounds. The condis state was newly discovered only four years
ago. In this article over 100 examples are discussed as example of
the condis state. In many cases the condis state was suggested for
the first time. Motion in the Condensed State, Condis Crystals and
their Relation to Plastic Crystals, Condis Crystals of Flexible
Macromolecules, Condis Crystals and their Relation to Liquid
Crystals, Condis Crystals of Stiff Macromolecules.
The book addresses three major topics in mathematical physics: 1.
recent rigorous results in potential theory with appli- cations in
particle physics, 2. analyticity in quantum field theory and its
applica- tions, and 3. fundamentals and applications of the inverse
problem. In addition, the book contains some contributions on
questions of general interest in quantum field theory such as
nonperturbative solutions of quantum chromodynamics, bifurcation
theory applied to chiral symmetry, as well as exactly soluable
models. The volume closes with a brief review of geometric
approaches to particle physics and a phenomenological discussion of
Higgs interactions.
At the time when increasing numbers of chemists are being attracted
by the fascination of supposedly easy computing and associated
colourful imaging, this book appears as a counterpoint. The first
part focuses on fundamental concepts of quantum chemistry, covering
MCSCF theory, perturbation treatments, basis set developments,
density matrices, wave function instabilities to correlation
effects, and momentum space theory. The second part is devoted to
more practical studies, ranging from the characterisation of exotic
interstellar molecules, the accurate determination of spectroscopic
constants, excited states structures and EPR parameters through
photochemical and charge-transfer processes, cluster chemistry and
fullerenes, muonium chemistry, to the possible prediction of the
response of materials to electric fields in view of nonlinear
optical applications. Audience: Graduate students and researchers
whose work involves quantum chemistry, molecular physics, and
materials modelling.
This volume contains the invited and contributed papers presented
at the Fourth International Conference on Perspectives in Hadronic
Physics and sent to the Editors within the deadline. The Conference
was held at the Abdus Salam International Centre for Theoretical
Physics (ICTP), Trieste, Italy, from May 12th to 16th, 2003, and
was attended by about 100 scientists from 20 countries. The series
ofConferences on Perspectives on Hadronic Physics takes place every
two years since 1997 and follows the seven Workshops on
Perspectives in Nuclear Physics at Intermediate Energies, organized
every two years at ICTP since 1983. The aim of these Conferences is
to discuss the status-of-the-art concerning the experimental and
theoretical investigations of hadronic systems, from nucleons to
nuclei and dense nuclear matter, in terms of the relevant
underlying degrees of freedom. For such a reason the Fourth
Conference has been focused on those experimental and theoretical
topics which have been in the last few years the object of
intensive investigations, viz. the various approaches employed to
describe the structure of hadrons in terms of QCD and QCD inspired
models, the recent developments in the treatment of the properties
and propagations of hadronic states in the medium, the relevant
progress done in the solution of the few- and many- hadron
problems, the recent results in the experimental investigation of
dense hadronic matter and, last but not least, the physics programs
of existing Laboratories and the suggested projects for new
Facilities.
Computer simulation has become a basic tool in many branches of
physics such as statistical physics, particle physics, or materials
science. The application of efficient algorithms is at least as
important as good hardware in large-scale computation. This volume
contains didactic lectures on such techniques based on physical
insight. The emphasis is on Monte Carlo methods (introduction,
cluster algorithms, reweighting and multihistogram techniques,
umbrella sampling), efficient data analysis and optimization
methods, but aspects of supercomputing, the solution of stochastic
differential equations, and molecular dynamics are also discussed.
The book addresses graduate students and researchers in theoretical
and computational physics.
Nuclear magnetic resonance spectroscopy, which has evolved only
within the last 20 years, has become one of the very important
tools in chemistry and physics. The literature on its theory and
application has grown immensely and a comprehensive and adequate
treatment of all branches by one author, or even by several,
becomes increasingly difficult. This series is planned to present
articles written by experts working in various fields of nuclear
magnetic resonance spectroscopy, and will contain review articles
as well as progress reports and original work, its main aim,
however, is to fill a gap, existing in literature, by publishing
articles written by specialists, which take the reader from the
introductory stage to the latest development in the field. The
editors are grateful to the authors for the time and effort spent
in writing the articles, and for their invaluable cooperation. The
Editors Contents P. Diehl and C. L. Khetrapal NMR Studies of
Molecules Oriented in the Nematic Phase of Liquid
Crystais......................................................... 1
R. G. Jones The Use of Symmetry in Nuclear Magnetic
Resonance................. 97 NMR Studies of Molecules Oriented in
the Nematic Phase of Liquid Crystals P. DIEHL and C. L. KHETRAPAL *
Department of Physics, University of Basel, Switzerland Contents 1.
Introduction . . . . . . . . . . . . . . . . . . . .. . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . 3 2. Liquid Crystals
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
. . . . . . . . . . . . . . 2.1. Classification of Liquid Crystal
Phases . . . . . . . . . . . . . . . . . . . . . . . 4 2.2.
Theories of the Liquid Crystalline State . . . . . . . . . . . . .
. . . . . . . . . 5 2.3. Nematic Phases . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.
Experimental . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . 7 1 4. Basic Theory
(for I = I ). . . . . . . . . . . . . * . . . . . . . . . . . . . .
. . . . . . . . . 7 . .
Photothermal science continues to be an area of rapid development
and active investigation, as is demonstrated by this volume. The
various contributions present fundamental research in materials
science, physics, chemistry, biology, and medicine, as well as
important applications of photothermal techniques in nondestructive
evaluation, aeronomy and pollution control, and other areas. The
topics treated include measurements of spectral properties of
gases, the theory of thermally generated elastic waves, a method of
monitoring local surface displacements, materials characterization
and nondestructive evaluation of materials, studies of the dynamics
of primary photophysical processes, fast energy exchange at
surfaces and at interfaces (e.g. in medicine and photobiology),
thermal EXAFS and XANES applied to metals and semiconductors, and
imaging of magnetic materials using microwave sources.
dissociation, E, of a dimer into two monomers and that, E', of a
trimer into a dimer and a monomer. The observed velocity
distribution for a beam of sodium iodide is shown in Fig. 23. The
monomer and dimer distributions, which are each of the form of Eq.
(9. 2), are separately shown. The sum of the two assumed
distributions is seen to agree with the experimental data. The data
for lithium bromide are shown in Fig. 24. The separate
distributions for the monomer, dimer, and trimer required to fit
the data are shown as is the sum of these distributions. An attempt
to describe the observed distribution in terms of a monomer and a
dimer only is shown by the dotted line, where the relative amounts
of these species have been adjusted to give a fit on the low
velocity side of the spectrum. Table 2. Summary oj data on the
degree of association oj diatomic molecules. The data on the
fluorides are from unpublished results of M. EISENSTADT, G.
ROTHBERG and P. KUSCH. Uncertainties in E and E' are given in
parentheses. E E' Temperature OK I ----- ----" Species at which a2
a, kcaljmole p 10-2mmHg RbCl 866 0. 063 48. 0 (0. 5) I KCI 0. 083
897 45.8 (0. 7) I KI 823 0. 046, 45.3 (0.9) NaC] 920 0. 259 44. 6
(0.9) i NaI 817 0. 235 38. 6 (3-4) LiC] 2."
Interface phenomena are most fascinating because of the mixing of
different scales and the interference of diverse physical
processes. This makes it necessary to use different levels of
description: microscopic, kinetic, and gas-dynamical. A unified
quasiclassical approach is used to answer practical questions
dealing with inelastic gas-surface scattering, the kinetics of
adsorption layers, the evolution of inhomogeneities and defects at
the surface, the Knudsen layer, the development of boundary
conditions on the kinetic and gas-dynamical levels, the
determination of exchange and slip coefficients, and so on.
The idea of this book originated from two series of lectures given
by us at the Physics Department of the Catholic University of
Petr6polis, in Brazil. Its aim is to present an introduction to the
"algebraic" method in the perturbative renormalization of
relativistic quantum field theory. Although this approach goes back
to the pioneering works of Symanzik in the early 1970s and was
systematized by Becchi, Rouet and Stora as early as 1972-1974, its
full value has not yet been widely appreciated by the practitioners
of quantum field theory. Becchi, Rouet and Stora have, however,
shown it to be a powerful tool for proving the renormalizability of
theories with (broken) symmetries and of gauge theories. We have
thus found it pertinent to collect in a self-contained manner the
available information on algebraic renormalization, which was
previously scattered in many original papers and in a few older
review articles. Although we have taken care to adapt the level of
this book to that of a po- graduate (Ph. D. ) course, more advanced
researchers will also certainly find it useful. The deeper
knowledge of renormalization theory we hope readers will acquire
should help them to face the difficult problems of quantum field
theory. It should also be very helpful to the more phenomenology
oriented readers who want to famili- ize themselves with the
formalism of renormalization theory, a necessity in view of the
sophisticated perturbative calculations currently being done, in
particular in the standard model of particle interactions.
Transitions from the innermost shells of iron, especially the K-
and L-shelllines, provide a powerful tool for probing the physical
characteristics of hot plasmas in X-ray sources. Their strength and
purity allow important conclusions to be drawn even with modest
energy resolution. They should also help in studying the regions
around black holes and neutron stars. In this book the state of the
art and themost recent theoretical and experimental observations
are presented. The book will be a valuable source for future
satellite missions. It addresses both researchers and graduate
students in astrophysics.
This collection of articles contains a systematic outline of
original experimental and theoretical research on photoproduction
of neutral pions at protons and at a strongly bound system of a few
nucleons, i.e., the helium nucleus. Spark chambers and their use as
spectrometers for photons and electrons are described in detail.
The articles of the collection include information on a novel
method of determining the efficiency of recording apparatus by
generating monochromatic photons. The articles de- scribe original
theoretical research on the optical anisotropy of nuclei. Problems
encountered in experimental studies of operating the synchrotron as
a storage-type accelerator of electrons and positrons receive
particular attention. The results of this research work are listed,
and the problems of oppositely directed electron-positron beams in
the 250-MeV synchrotron are considered. The articles should be of
interest to physicists, including research workers, teachers,
engineers, graduate students, and students in advanced
undergraduate courses. v CONTENTS Photoproduction of Neutral Pions
at Nucleons and Nuclei B. B. Govorkov, S. P. Denisov, and E. V.
Minarik 0 Photoproduction of 1r Mesons at Helium and at Photon
Energies of 71 160-240 MeV ...
In the last twenty years polarized beams of slow neutrons have been
used effectively in fundamental research in nuclear physics. Parity
violation in nuclear fission and neutron optics was discoverd as
well as the nuclear precession of neutrons and the coherent
interference of spin channels in neutron capture by nuclei.
Furthermore, these methods helped to understand better the
neutron`s electric dipole moment and its beta decay. This book
gives a thorough introduction to these experimental methods
including the most recent techniques of generating and analyzing
polarized neutral beams. It clearly shows the close relationship
between elementary particle physics and nuclear physics, in
particular in the section dealing with the effects caused by weak
interactions. Special attention is paid to experiments which
investigate the violation of quantum mechanical conservation laws.
The book not only addresses specialists but also those interested
in the foundations of elementary particle and nuclear physics. It
is well suited as additional reading for students.
The investigation of scattering phenomena is a major theme of
modern physics. A scattered particle provides a dynamical probe of
the target system. The practical problem of interest here is the
scattering of a low energy electron by an N-electron atom. It has
been difficult in this area of study to achieve theoretical results
that are even qualitatively correct, yet quantitative accuracy is
often needed as an adjunct to experiment. The present book
describes a quantitative theoretical method, or class of methods,
that has been applied effectively to this problem. Quantum
mechanical theory relevant to the scattering of an electron by an
N-electron atom, which may gain or lose energy in the process, is
summarized in Chapter 1. The variational theory itself is presented
in Chapter 2, both as currently used and in forms that may
facilitate future applications. The theory of multichannel
resonance and threshold effects, which provide a rich structure to
observed electron-atom scattering data, is presented in Chapter 3.
Practical details of the computational implementation of the
variational theory are given in Chapter 4. Chapters 5 and 6
summarize recent appli cations of the variational theory to
problems of experimental interest, with many examples of the
successful interpretation of complex structural fea tures observed
in scattering experiments, and of the quantitative prediction of
details of electron-atom scattering phenomena."
Il capitano generale lagrimo per allegrezza e nomino quel capo:
Deseado, perehe l'avevamo gia gran tempo desiderato. Antonio
Pigafetta Il Primo Viaggo in torno al Mondo I would like to take
some poetic license in introducing this volume in a way that seems
appropriate for a country, like Chile, that Iooks to the ocean. I
believe it was Heisenberg who compared different times in physics
with sailing a ship. He said that most of the time we keep our
ships in port, or in the protection of a bay. But on a few
occasions we go into the open sea, and those occasions are really
the great times in theoretical physics, when everything can change.
It does not seem totally unwarranted to hope that we are now
entering one of those times. In that spirit, I would like to
mention a wonderful book, which in English would be called
something like Chile, Or a Crazy Geography.
Powerful new techniques, including heavy ion and exotic beams,
are pushing the frontiers of nuclear physics and opening up a
wealth of new fields of research. After introductory chapters on
theoretical and experimental aspects of nuclear collisions and
beams, Exotic Nuclear Physics'' offers articles by experienced
lecturers on forefront topics in nuclear physics, such as the
conquest of the neutron and the proton drip-lines, nuclear
astrophysics, the equation of state of hypernuclear matter, nuclear
supersymmetry and chaotic motion in nuclei. This volume continues
the successful tradition of published lecture notes from the
Hispalensis International Summer School. It will benefit graduate
students and lecturers in search of advanced material for
self-study and courses as will as researchers in search of a modern
and comprehensive source of reference.
A variety of novel applications for the investigation of disordered
surfaces by beams of thermal energy atoms are discussed and
illustrated by numerous examples. A straightforward semiclassical
approach is introduced to yield a remarkably detailed insight into
the lateral distributions of diffuse scatterers such as adsorbates,
vacancies and atomic steps. The recent discovery that the long
range Van der Waals force is the cause of the unusually large
cross-sections for diffuse He-scattering on individual defects and
impurities led the authors to propose a new methods of surface
analysis. They introduce a semiclassical method, the overlap
approach, to give a simple and detailed description of
He-scattering from disordered surfaces. The method yields subtle,
otherwise hardly obtainable information on the nature of
interactions between diffuse scatterers. The authors address such
questions as the lateral distribution of adsorbates,
two-dimensional phase transitions, surface diffusions, and the
morphology of growing or sputtered layers.
Physicists who wish to understand the modeling of confinement of
quantum chromodynamics, as exhibited by dual superconductors, will
find this book an excellent introduction. The author focuses on the
models themselves, especially the Landau--Ginzburg model of a dual
superconductor, also called the Dual Abelian Higgs model.
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