John R. Barker - Böcker

The technological means now exists for approaching the fundamentallimiting scales of solid state electronics in which a single carrier can, in principle, represent a single bit in an information flow. In this light, the prospect of chemically, or biologically, engineered molccular-scale structures which might support information processing functions has enticed workers for many years. The one common factor in all suggested molecular switches, ranging from the experimentally feasible proton-tunneling structure, to natural systems such as the micro-tubule, is that each proposed structure deals with individual information carrying entities. Whereas this future molecular electronics faces enormous technical challenges, the same Iimit is already appearing in existing semiconducting quantum wires and small tunneling structures, both superconducting and normal meta! devices, in which the motion of a single eh arge through the tunneling barrier can produce a sufficient voltage change to cut-off further tunneling current. We may compare the above situation with today's Si microelectronics, where each bit is encoded as a very !arge number, not necessarily fixed, of electrons within acharge pulse. The associated reservoirs and sinks of charge carriers may be profitably tapped and manipulated to proviele macro-currents which can be readily amplified or curtailed. On the other band, modern semiconductor ULSI has progressed by adopting a linear scaling principle to the down-sizing of individual semiconductor devices.

The technological means now exists for approaching the fundamentallimiting scales of solid state electronics in which a single carrier can, in principle, represent a single bit in an information flow. In this light, the prospect of chemically, or biologically, engineered molccular-scale structures which might support information processing functions has enticed workers for many years. The one common factor in all suggested molecular switches, ranging from the experimentally feasible proton-tunneling structure, to natural systems such as the micro-tubule, is that each proposed structure deals with individual information carrying entities. Whereas this future molecular electronics faces enormous technical challenges, the same Iimit is already appearing in existing semiconducting quantum wires and small tunneling structures, both superconducting and normal meta! devices, in which the motion of a single eh arge through the tunneling barrier can produce a sufficient voltage change to cut-off further tunneling current. We may compare the above situation with today's Si microelectronics, where each bit is encoded as a very !arge number, not necessarily fixed, of electrons within acharge pulse. The associated reservoirs and sinks of charge carriers may be profitably tapped and manipulated to proviele macro-currents which can be readily amplified or curtailed. On the other band, modern semiconductor ULSI has progressed by adopting a linear scaling principle to the down-sizing of individual semiconductor devices.

Atmospheric chemistry is central to understanding global changes — ozone depletion, appearance of the polar ozone holes, and compositional changes which worsen the greenhouse effect. Because of its importance, work is progressing on many fronts.This volume emphasizes the troposhere and stratosphere and has chapters on gas phase, condensed phase, and heterogeneous chemistry. Present progress is emphasized, and important future directions are also described.This book fills a need not satisfied by any others and will be popular for some years to come. It informs students and newcomers to the field of the many facets of atmospheric chemistry and can be used as a text for advanced students. It is also a valuable desk reference summarizing activities by quite a number of the most active research groups.Chapter 18 by Kolb et al. on heterogeneous chemistry is especially noteworthy because it represents a unique joint effort by several groups working on a very timely subject; they describe a conceptual framework and establish conventions which will be standard in future papers on this subject.

Atmospheric chemistry is central to understanding global changes — ozone depletion, appearance of the polar ozone holes, and compositional changes which worsen the greenhouse effect. Because of its importance, work is progressing on many fronts.This volume emphasizes the troposhere and stratosphere and has chapters on gas phase, condensed phase, and heterogeneous chemistry. Present progress is emphasized, and important future directions are also described.This book fills a need not satisfied by any others and will be popular for some years to come. It informs students and newcomers to the field of the many facets of atmospheric chemistry and can be used as a text for advanced students. It is also a valuable desk reference summarizing activities by quite a number of the most active research groups.Chapter 18 by Kolb et al. on heterogeneous chemistry is especially noteworthy because it represents a unique joint effort by several groups working on a very timely subject; they describe a conceptual framework and establish conventions which will be standard in future papers on this subject.

The human race has altered the chemical composition of the atmosphere, as evidenced by the notorious London smog, photochemical air pollution, acid rain, stratospheric ozone depletion, and elevated greenhouse gas concentrations. The aim of this book series is to present invited summaries of important current research on atmospheric chemistry in a changing world. The summaries range from comprehensive scholarly reviews of major subject areas to more narrowly focused accounts of recent advances by individual research groups. The topics are tied to the important societal issues of air quality, stratospheric ozone depletion, acid deposition, the environmental fate of toxics, and climate change. By gathering these new Advances in one series, we aim to catalyze communication among the many researchers who are studying our changing, contemporary atmosphere.

This series presents authoritative invited summaries of research on atmospheric chemistry in a changing world. These range from comprehensive reviews of major subject areas to focused accounts by individual research groups. The topics may include laboratory studies, field measurements, in situ monitoring and remote sensing, studies of composition, chemical modeling, theories of atmospheric chemistry and climate, feedback mechanisms, emissions and deposition, biogeochemical cycles, and the links between atmospheric chemistry and the climate system at large.Volume 2 comprises chapters describing research on multiphase chemistry affecting air quality in China, on multiphase chemistry of organic compounds leading to secondary organic aerosol formation, on biogeochemical cycles involving ammonia, on oxidation of aromatic compounds, on reactions of Criegee intermediates (important in oxidation of alkenes), and on laboratory and field measurements of isotopic fractionation in the atmosphere.