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Books > Science & Mathematics > Physics > Atomic & molecular physics
Written in a pedagogical way, the articles in this book address
graduate students as well as researchers and are well suited for
seminar work. Subjects at the forefront of nuclear research,
bordering other areas of many-particle physics, such as electron
scattering at different energy scales, new physics with radioactive
beams, multifragmentation, relativistic nuclear physics, high spin
nuclear problems, chaos, the role of the continuum in nuclear
physics or recent calculations with the shell model are presented.
It is felt that the topics treated in this book address the main
future lines of development of nuclear physics.
In this volume, experimentalists and theoreticians discuss which
experiments and calculations are needed to make significant
progress in the field and also how experiments and theoretical
descriptions can be compared. The topics treated are the
electromagnetic production of Goldstone bosons, pion--pion and
pion--nucleon interactions, hadron polarizability and form factors.
The aesthetically pleasing molecular architectures of fullerenes
and nanotubes are appealing not only because of their beauty but
also because they are responsible for the many unprecedented
chemical and physical properties of this compound class. Although
succession of exciting new discoveries continues unabated fullerene
research has become a mature science. It is now possible to predict
fullerene chemistry, to design new structure variations like open
fullerene clusters, heterofullerenes and endohedral fullerenes, and
to develop fullerene materials and modified nanotubes with high
potential for technological applications. This volume represents
the state-of-the-art of fullerene research, focussing on areas
showing high potential for future growth and practical
applications. The authors are leading scientists whose groups are
making major contributions in the field.
The Aharonov-Bohm effect is associated with cyclic motion. It is
one of a number of anholonomic effects, and this means that the
dynamical description depends on the current position of the system
and on the path by which it reached that position.
An example of an anholonomic effect is Foucault's famous pendulum,
which simply demonstrates the Earth's rotation. The Sagnac effect -
a light beam passing around a rotated system of mirrors - is
another example. Modern dynamical developments such as Hannay's
angle and Berry's phase are further useful examples.
Prominent progress in science is inevitably associated with
controversies. Thus, young researchers, in particular, have to
learn how to persevere during the period of controversy and
struggle for acceptance. Unfortunately, the skills needed are not
taught in textbooks or monographs, which mostly describe the
consensus of contemporary experts.
This book, which is based on my own experiences as a scientist,
describes the history of the progress made in auroral science and
magnetospheric physics by providing examples of ideas,
controversies, struggles, acceptance, and success in some
instances.
Although no general methodology (if any exists) is mentioned, I
hope that the reader will learn about the history of progress in
auroral science and examples (right or wrong) of dealing with the
controversies.
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."
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.
photoacoustic and Photothermal Phenomena contains reviews and a
large numberof selected contributed papers reporting progress in
the application of new photoacoustic and photo- thermal techniques
in physics, chemistry, biology, medicine and materials science.
Theoretical and experimental work is presented on spectroscopy,
kinetics and relaxation, trace analysis, mass and heat transport,
surfaces and thin films, nondestructive evaluation, ultrasonics and
semiconductors.
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.
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.
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 . .
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.
This textbook is intended as an introduction to the physics of
solar and stellar coronae, emphasizing kinetic plasma processes. It
is addressed to observational astronomers, graduate students, and
advanced undergraduates without a ba- ground in plasma physics.
Coronal physics is today a vast field with many different aims and
goals. So- ing out the really important aspects of an observed
phenomenon and using the physics best suited for the case is a
formidable problem. There are already several excellent books,
oriented toward the interests of astrophysicists, that deal with
the magnetohydrodynamics of stellar atmospheres, radiation
transport, and radiation theory. In kinetic processes, the
different particle velocities play an important role. This is the
case when particle collisions can be neglected, for example in very
brief phenomena - such as one period of a high-frequency wave - or
in effects produced by energetic particles with very long collision
times. Some of the most persistent problems of solar physics, like
coronal heating, shock waves, flare energy release, and particle
acceleration, are likely to be at least partially related to such
p- cesses. Study of the Sun is not regarded here as an end in
itself, but as the source of information for more general stellar
applications. Our understanding of stellar processes relies
heavily, in turn, on our understanding of solar processes. Thus an
introduction to what is happening in hot, dilute coronae
necessarily starts with the plasma physics of our nearest star.
Neutron radiography has in recent years emerged as a useful and
complementary technology for radiation diagnosis. It is now
routinely used in industrial quality assurance and in support of
selected research and developmental activities. Conferences are
held on the subject, pertinent handbooks exist, and technical
papers appear regularly reporting on new developments. While
neutron radiography has indeed passed through the transition from a
scientific curiosity to technological relevance, it is a sign of
its continuing dynamic evolution that little material has appeared
which provides an integrated mathematical and physical analysis of
the subject possessing both an instructional as well as reference
function. It is our hope that this monograph will fill this need.
The distinctiveness of neutron radiography rests on the unique
interactions between neutrons and nuclei. This leads to some
special relationships between the material and geometrical
properties of an object and the neutron radiographic image. The
evolution of a technical discipline demands that specific
conceptual constructs be developed and their mathematical
representations examined and compared with controlled experiments.
Experience has convinced us that a particular and substantial body
of knowledge has accumulated endowing neutron radiography with the
essential foundations of a unique mathematical and physical
science. Our scientific and professional involvement in neutron
radiography began some 15 years ago when the senior author (A.A.H.)
found himself with convenient access to the McMaster University
Nuclear Reactor and research support from the Government of Canada.
This book is intended to give an introduction to intermolecular
forces from an experimental point of view. Within the last 10 years
the interest has turned more and more into an understanding of the
weak, but important, int- molecular forces. New experimental
techniques have been developed which have helped to gain more
insight into this interesting topic. This book is intended as an
introduction for graduate students who are familiar with the main
concepts of n olecular spectroscopy. Special emphasis will be laid
on the theoretical concepts. After a detailed description of
experimental techniques, the results for two prototype systems
which have been the subject of several studies in the literature
within recent years will be presented. Ar-CO is becoming the most
extensively studied van der Waals complex, theoretically and
experimentally. Nevertheless, this example shows that even though
the theory has greatly improved and has helped us to improve our
knowledge of intermolecular forces, even for relatively simple
cases the theory car1 still fall short of an accurate description.
For a long time (NH3)2 was considered as a prototype for hydrogen
bo- ing. However, subsequent experimental and theoretical studies
have revealed the mysteries of the obtained spectra and proved that
our previous concept of hydrogen bonds was just too naive.
The optical trapping of colloidal matter is an unequalled field of
technology for enabling precise handling of particles on
microscopic scales, solely by the force of light. Although the
basic concept of optical tweezers, which are based on a single
laser beam, has matured and found a vast number of exciting
applications, in particular in the life sciences, there are strong
demands for more sophisticated approaches. This thesis gives an
introductory overview of existing optical micromanipulation
techniques and reviews the state-of-the-art of the emerging field
of structured light fields and their applications in optical
trapping, micromanipulation, and organisation. The author presents
established, and introduces novel concepts for the holographic and
non-holographic shaping of a light field. A special emphasis of the
work is the demonstration of advanced applications of the thus
created structured light fields in optical micromanipulation,
utilising various geometries and unconventional light propagation
properties. While most of the concepts developed are demonstrated
with artificial microscopic reference particles, the work concludes
with a comprehensive demonstration of optical control and alignment
of bacterial cells, and hierarchical supramolecular organisation
utilising dedicated nanocontainer particles.
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.
The papers collected in this volume have been presented during a
workshop on "Electron-Atom and Molecule Collisions" held at the
Centre for Interdisciplinary Studies of the University of Bielefeld
in May 1980. This workshop, part of a larger program concerned with
the "Properties and Reactions of Isolated Molecules and Atoms,"
focused on the theory and computational techniques for the quanti
tative description of electron scattering phenomena. With the
advances which have been made in the accurate quantum mechanical
characterisation of bound states of atoms and molecules, the more
complicated description of the unbound systems and resonances
important in electron collision processes has matured too. As expli
cated in detail in the articles of this volume, the theory for the
quantitative explanation of elastic and inelastic electron molecule
collisions, of photo- and multiple photon ionization and even for
electron impact ionization is well developed in a form which lends
itself to a complete quantitative ab initio interpretation and pre
diction of the observable effects. Many of the experiences gained
and the techniques which have evolved over the years in the com
putational characterization of bound states have become an
essential basis for this development. To be sure, much needs to be
done before we have a complete and detailed theoretical
understanding of the known collisional processes and of the
phenomena and effects, which may still be un covered with the
continuing refinement of the experimental tech niques.
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