Order-disorder transition in monodisperse latex is reviewed from experimental and theor-etical points of view. The ordered arrays of latex particles are found to be a good model for crystal growth and melting phenomena. It is emphasized that order-disorder transition in mo-nodisperse latex is essentially the same phenomena as solid-liquid transition in molecular level and cannot be explained by the present theory of colloid interaction. Recent advances in co-mputer experiment on solid-liquid transition is also reviewed and the idea of Alder transition is introduced. Experimental results seem to support the existence of Alder transition in monodisperse latex.
Investigations were carried out on Si-SiO2 interface states induced by the implantation of various ion species such as He, B, N, O, Ne, Al, Si and P. Energy distribution of the induced interface state density was determined from the quasi-static capacitance-voltage curve of the implanted MOS structures. Density of charged interface states was found to be proportional to the number of displaced atoms produced in silicon, and was independent of the ion species implanted. Besides the continuously distributed interface states in the energy band of substrate silicon, a discrete energy level was observed around 0.4 eV from the conduction band edge, independent of the ion species implanted. Annealing extinguished these continuously distributed and discrete states in the 200-400°C range with an activation energy of 0.3-0.4 eV. Some kind of vacancy complexes in silicon substrate are conjectured as the origin of these interface states.
The polymerization of acrylamide in aqueous solution was carried out with β-irradiation facilities using unsealed 85Kr gas as an internal radiation source. Irradiation experiments were made in a reaction vessel of 1 l capacity with 290 Ci of 85Kr. The effects of dose rate, monomer concentration, and polymerization temperature on the polymerization rate were studied. The experimental results were compared with the results using 131Cs as a source. It is observed that the polymerization rate, for either source, is proportional to the 0.55th power of dose rate and the 1st power of monomer concentration. In addition, the activation energy of polymerization is 1.8kcal/mol. It can be considered that there is no particular distinction in the polymerization rates due to difference in the radiation source.
A technique to reconstruct images from acoustical holograms by computer is proposed and theoretical and experimental discussions on this technique are conducted. The criteria on the sampling number and the aperture applicable for the shifted image are analyzed. The periodic image due to the fast Fourier transform algorithm is also discussed. Acoustical holograms are constructed with 15 kHz sound-wave using electronic references. The holograms printed in photographs are sampled and quantized for computer reconstruction. Images are reconstructed by calculating the discrete Fresnel transform of the quantized holograms. Image shift and periodic images are discussed by experimental results. The reconstructed images are observed by changing the sampling number of the hologram.