On the memory processes and the memory location in the central nervous system, we introduce two kind of brain models. One is the models based on the holography or the Bose-Einstein Condensation, which are existing as physical theories. This type of model is related to the activities of the whole brain as a cluster. It can be called a macroscopic model. The other is a microscopic model of the brain. It is based on the electrophysiological evidence of the activities of a single neuron. The single neuron is a fundamental unit of the brain. The activity of any single neuron, however, might not be so significant for the functioning of the whole brain, but the patterns of activities of the neuronal network may be rather important in the nervous system, the components of which are too much to be handled piece by piece. The macroscopic system simulation of the brain seems to be more promising in the future research of learning or memory processes.
The FEM W-tip which initially has the shape of a needle (the radii of curvature 5×10-6_??_1.510-5 cm) was inserted into a special specimen chamber of an electron microscope and the changes of shape by heating were observed over a wide range of temperatures (1600°K_??_2800°K) either continuously or intermittently. The receding rate by the blunting of the tip was determined by an application of Herring's theory on transport phenomena in solid to field emission cathode. It was found from the experimental results that the receding rate of the tip depended on the cone angle. Furthermore, the process of typical changes in the shape of the tip was established, and why a neck formed in the region near the tip could be explained.
The crystallization of vitreous compounds As2 (Se1-XTeX)3 (X=1/4, 1/3, 1/2, 2/3, 3/4) was investigated in the temperature range from 150°C to 300°C by the use of microscopic, electrical and X-ray diffraction methods. From the microscopic observation, it was found that at the early stage of crystallization, nuclei appeared on the surface of the specimen and grew into the specimen in the form of a layer. During on the final stage, other nuclei appeared inside the specimen and grew spherically with the same linear crystallization rate as that of surface nuclei, and thus completed the crystallization of the whole specimen. From the temperature dependence of linear growth rate, the activation energy for the crystallization is found to be nearly the same in the wide composition range studied : namely, 1.4±0.2 eV. From electrical and X-ray studies, specimens were known to crystallize into two different crystal structures: the high temperature phase and the low temperature phase, bordered by a critical temperature. The specimen crystallized into a mixed structure of both phases near the critical temperature.
Various focusing properties of electrostatic symmetrical quadrupole triplet lens were calculated using a digital computer, and the results were compared with experiments on electron beam focusing. The lens system consisted of two outside sections having equal length L and a middle section of length 2L, separation between each section being equal to L. The conditions and limits for astigmatic, pseudo-stigmatic, and stigmatic operations were clearly distinguished. The some what complicated variation of magnification factors with image distance under given object distances could be precisely explained by variation of positions of the principal planes. The effects of fringing fields were discussed using equivalent length concepts. It was found that these effects were not so important in such a lens system. The experimental results agreed well with the calculated values using a rectangle model of the actual field.
The structure of the cross section of evaporated thin gold films was investigated electron micrographically by applying the replica technique. Au was used as an evaporating source, and the temperature of the glass substrate was changed from 80°C to 370°C under a constant deposition rate. From observation of the cross section it became evident that, when the temperature of the substrate is higher than about 300°C, the film growth proceeds through coalescence between the islands, however, at a lower temperature the coalescence seems to take place only between the upper strata of the islands. It is also shown that the size of an island, which becomes larger in accordance with the increase of the film thickness, has a maximum limit, above which the island changes its form abruptly into a continuous film.