Zewail Ahmed H Zewail – författare

The modern electron microscope, as a result of recent revolutionary developments and many evolutionary ones, now yields a wealth of quantitative knowledge pertaining to structure, dynamics, and function barely matched by any other single scientific instrument. It is also poised to contribute much new spatially-resolved and time-resolved insights of central importance in the exploration of most aspects of condensed matter, ranging from the physical to the biological sciences.Whereas in all conventional EM methods, imaging, diffraction, and chemical analyses have been conducted in a static — time-integrated — manner, now it has become possible to unite the time domain with the spatial one, thereby creating four-dimensional (4D) electron microscopy. This advance is based on the fundamental concept of timed, coherent single-electron packets, or electron pulses, which are liberated with femtosecond durations. Structural phase transitions, mechanical deformations, and the embryonic stages of melting and crystallization are examples of phenomena that can now be imaged in unprecedented structural detail with high spatial resolution, and ten orders of magnitude as fast as hitherto.No monograph in existence attempts to cover the revolutionary dimensions that EM in its various modes of operation nowadays makes possible. The authors of this book chart these developments, and also compare the merits of coherent electron waves with those of synchrotron radiation. They judge it prudent to recall some important basic procedural and theoretical aspects of imaging and diffraction so that the reader may better comprehend the significance of the new vistas and applications now afoot.This book is not a vade mecum — numerous other texts are available for the practitioner for that purpose. It is instead an in-depth exposé of the paradigm concepts and the developed techniques that can now be executed to gain new knowledge in the entire domain of biological and physical science, and in the four dimensions of space and time.

This is an avant-garde book edited by Nobel Laureate Ahmed Zewail with contributions from eminent scientists including four Nobel prize winners. The perspectives of these world leaders in physics, chemistry, and biology define potential new frontiers at the interface of disciplines and including physical, systems, and synthetic biology.This book brings about the confluence of concepts and tools, and that of different disciplines, to address significant problems of our time: visualization; theory and computation for complexity; macromolecular function, protein folding and misfolding; and systems integration from cells to consciousness. The scope of tools is wide-ranging, spanning imaging, crystallography, microfluidics, single-molecule spectroscopy, and synthetic probe targeting. Concepts such as dynamic self-assembly, molecular recognition, non-canonical amino acids, and others are covered in various chapters as they are cornerstones in building the trilogy description of behavior-structure, dynamics, and function.The volume is uniquely structured to provide overviews with historical perspectives on the evolution of ideas and on the future of physical biology and biological complexity, from atoms to medicine.

From a beginning in an Egyptian delta town and the port of Alexandria to the scenic vistas of sunny southern California, Ahmed Zewail takes us on a voyage through time — his own life and the split-second world of the femtosecond. In this endearing exposé of his life and work until his receipt of the Nobel Prize in 1999, he draws lessons from his life story so far, and he meditates on the impact which the revolution in science has had on our modern world — in both developed and developing countries. What makes the book enchanting and engaging is Zewail''s emphasis on the human dimension and his unique ability to paint the journey of Life and Science with insightful analogies and ingenious metaphors.But this inspiring book goes far beyond the usual province of an autobiography. Zewail integrates the two worlds he equally belongs to — Egypt and America — and, despite differences, he emphasizes the confluence of the two cultures — the East and the West. He rejects the view that the current state of the world is due to a clash of civilizations or a conflict of religions, and suggests a concrete course of action for the world of the have-nots. The book ends with his road map for a partnership between developed and developing worlds. Throughout the book, Zewail takes on the mantle of philosopher, historian and even political and economic adviser.

These two volumes on Femtochemistry present a timely contribution to a field central to the understanding of the dynamics of the chemical bond. This century has witnessed great strides in time and space resolutions, down to the atomic scale, providing chemists, biologists and physicists with unprecedented opportunities for seeing microscopic structures and dynamics. Femtochemistry is concerned with the time resolution of the most elementary motions of atoms during chemical change - bond breaking and bond making - on the femtosecond (10-15 second) time scale. This atomic scale of time resolution has now reached the ultimate for the chemical bond and as Lord George Porter puts it, chemists are near the end of the race against time. These two volumes cover the general concepts, techniques and applications of femtochemistry.Professor Ahmed Zewail, who has made the pioneering contributions in this field, has from over 250 publications selected the articles for this anthology. These volumes begin with a commentary and a historical chronology of the milestones. He then presents a broad perspective of the current state of knowledge in femtochemistry by researchers around the world and discusses possible new directions. In the words of a colleague, '';it is a must on the reading-list for all of my students ...; all readers will find this to be an informative and valuable overview.'';The introductory articles in Volume I provide reviews for both the non-experts as well as for experts in the field. This is followed by papers on the basic concepts. For applications, elementary reactions are studied first and then complex reactions. Volume I is complete with studies of solvation dynamics, non-reactive systems, ultrafast electron diffraction and the control of chemical reactions.Volume II continues with reaction rates, the concept of elementary intramolecular vibrational-energy redistribution (IVR) and the phenomena of rotational coherence which has become a powerful tool for the determination of molecular structure via time resolution. The second volume ends with an extensive list of references, according to topics, based on work by Professor Zewail and his group at Caltech.These collected works by Professor Zewail will certainly be indispensable to both experts and beginners in the field. The author is known for his clarity and for his creative and systematic contributions. These volumes will be of interest and should prove useful to chemists, biologists and physicists. As noted by Professor J Manz (Berlin) and Professor A W Castleman, Jr. (Penn State): femtochemistry is yielding exciting new discoveries from analysis to control of chemical reactions, with applications in many domains of chemistry and related fields, e.g., physical, organic and inorganic chemistry, surface science, molecular biology, ...; etc.