Symmetries and singularity structures play important roles in the study of nonlinear dynamical systems. It was Sophus Lie who originally stressed the importance of symmetries and invariance in the study of nonlinear differential equations. How ever, the full potentialities of symmetries had been realized only after the advent of solitons in 1965. It is now a well-accepted fact that associated with the infinite number of integrals of motion of a given soliton system, an infinite number of gep. eralized Lie BAcklund symmetries exist. The associated bi-Hamiltonian struc ture, Kac-Moody, Vrrasoro...

This book deals with the mechanism of signal transduction in vertebrate and invertebrate photoreceptors. It contains contributions on the structure and function of rhodopsin or other G-coupled receptors, on the regulation of second messengers by enzyme cascade, the role of Ca2+ in light adaptation, control of ionic channels in photoreceptor cells.

Advances in the physics and chemistry of low-dimensional systems have been really magnificent in the last few decades. Hundreds of quasi-one-dimensional and quasi-two-dimensional systems have been synthesized and studied. The most popular representatives of quasi-one-dimensional materials are polyacethylenes CH 1] and conducting donor-acceptor molecular crystals TIF z TCNQ. Examples of quasi-two-dimensional systems are high temperature su perconductors (HTSC) based on copper oxides LA2CU04, YBa2Cu306+y and organic superconductors based on BEDT -TIP molecules. The properties of such one- and...

Presents contributions to the understanding of the complementary aspects of nonlinearity - solitons and chaos. The papers cover a range of topics but share common mathematical notions and investigation techniques.

This booklet presents a study of one-dimensional waves in solids which can be modelled by nonlinear wave equations of different types. The factorization method is the main tool in this analysis. It allows for an exact or at least asymp- totic decomposition of the wave(s) under consideration in terms of first order multipliers. Chapter 1 provides a general introduction. It presents some well-known results on characteristics, Riemann invariants, simple waves, etc. The main result of Chap. 1 is Theorem 1.3.2. (Sect. 1.3.2) which establishes the possibility of exact factorization of the nonlinear...

The results of a conference held in Kiev which provided reviews and papers on experimental aspects of these superconductors. The contributors discussed electronic and magnetic properties, emission and optic spectra, metallization processes, fluctuations, thin films and pinning.

Due to new technological progress in the development of ion sources and accelerators interesting kinds of beams are now available. They open new fields for materials research with ion beams. The present status and future possibilities of these research activities are described by experts on this field in the form of review articles. The papers presented in the book focus on very different aspects ranging from the field of truly appliedresearch to the field of fundamental atomic research investigating interaction mechanisms of slow, highly charged particles with surfaces. The book is intended...

Given the problems of the environment in relation to the ever-growing civi lization activities of man, it is not surprising that in recent years more and more related data have been collected, phenomena have been observed and concerns have been expressed. The ecological systems of man's environment react to the impact of these civilization activities. In fact, quite often these reactions occur as shocks and surprises. Acid rain and the related forest die backs are but one example. Ecological systems consist of many compo nents and their dynamics is thus complex. The study of complexity is the...

This book describes the Proceedings of the International Conference on Nuclear Data for Science and Technology held at Jillich in May 1991. The conference was in a series of application oriented nuclear data conferences organized in the past under the auspices of the Nuclear Energy Agency-Nuclear Data Committee (NEANDC) and with the support of the Nuclear Energy Agency-Committee on Reactor Physics (NEACRP). It was the fIrst international conference on nuclear data held in Germany, with the scientific responsibility entrusted to the Institute of Nuclear Chemistry of the Research Centre...