springer us jun 1990 (2 Ergebnisse)

Buch. Zustand: Neu. Neuware - A modern microelectronic circuit can be compared to a large construction, a large city, on a very small area. A memory chip, a DRAM, may have up to 64 million bit locations on a surface of a few square centimeters. Each new generation of integrated circuit- generations are measured by factors of four in overall complexity -requires a substantial increase in density from the current technology, added precision, a decrease of the size of geometric features, and an increase in the total usable surface. The microelectronic industry has set the trend. Ultra large funds have been invested in the construction of new plants to produce the ultra large-scale circuits with utmost precision under the most severe conditions. The decrease in feature size to submicrons -0.7 micron is quickly becoming availabl- does not only bring technological problems. New design problems arise as well. The elements from which microelectronic circuits are build, transistors and interconnects, have different shape and behave differently than before. Phenomena that could be neglected in a four micron technology, such as the non-uniformity of the doping profile in a transistor, or the mutual capacitance between two wires, now play an important role in circuit design. This situation does not make the life of the electronic designer easier: he has to take many more parasitic effects into account, up to the point that his ideal design will not function as originally planned.

Buch. Zustand: Neu. Neuware - During the last ZO years great progress has been achieved in our understanding of both earth history and vertebrate evolution. The result is that climatic/tectonic events in earth history can now be placed in a more precise and global time frame, that permit their evaluation as abiotic causal factors which might trigger extinction and dispersal events in vertebrate history. Great strides have also been made in genetics and cell biology, providing new insight into phylogenetic relationships among many vertebrates. These new data, along with data on chronologie resolution of earth history, provide tests of previous interpretations regarding ancestral-descendant relationships based solely on the fossil record. It is fitting and proper that a volume on European Neogene mammal chronology is produced at this time, to ensure that new interpretations of vertebrate evolution and chronology are based on the most accurate and current data. Vertebrate paleon tologists believe that the fossil record is the only secure data for measuring the actual course and tempo of vertebrate evolution. Knowledge of the fossil record must keep pace with advances in other areas of science so that inferences on vertebrate evolu tion are accurate and meaningful.