Educational equipment in the periphery of a large computer

Two practical examples of educational equipment in the periphery of a large (or medium) computer are described. The management system for lessons with several video displays is illustrated by a flow chart, and the total load to the central processor is assessed. A demonstration equipment which combines a graphic display, a scan-converter and a projection TV, is shown to be valuable. Possibilities of improvement are indicated.     

Transition moment directions of some important in-plane vibrations of uracil,thymine and cytosine. A fixed partial charge model calculation

Transition moment directions for the double-bond region vibrations of uracil, thymine and cytosine are calculated using the fixed partial charge model approximation. The coupling between the two carbonyl bonds and the carbon—carbon double bond in uracil and thymine is sensitive to the choice of the corresponding stretching force constants. The transition moment directions are correspondingly changed, thus, in principle, enabling the quantitative determination of coupling between the vibrations from linear dichroism measurements.     

Laser damage of silicon solar cells with different surface states

An experimental study of the damage of Si solar cells due to Q-switched ruby laser radiation has been made. Four kinds of specimen with different surface states were used in order to examine how the damage depends on the surface state: (a) chemically etched to a mirror finish, (b) mechanically polished by a 0.5 m Al₂O₃ powder, (c) chemically etched, but rough, (d) coated with SiO on the (c) surface. The threshold power densities, at which a change in the photo-current occurs, were for the specimens (a) to (d) respectively 60 MW cm^–2, 20 MW cm^–2, 30 MW cm^–2 and 9 MW cm^–2. Attenuations of the photo-current of the specimens, a, c and d were observed over the whole range of wavelength 500 to 1000 nm. For the b cell, however, increase of the photo-current was observed mainly in the short wavelength region.     

Effect of counterion species on colloidal crystal

The effect of counterion species on the colloidal crystal structure in a dispersion was carefully investigated as a function of the degree of neutralization (alpha) by the ultra-small-angle X-ray scattering technique. The nearest neighbor interparticle distance (2D(exp)) first increased with decreasing alpha, and then decreased after passing through the maximum. This behavior was confirmed for K(+), Li(+), Ca(2+), TMA(+) (tetramethylammonium) as a counterion, and Na(+) in our previous report (Harada, T.; Matsuoka, H.; Ikeda, T.; Yamaoka, H. Langmuir 2000, 16, 1612). However, the alpha value of the maximum position (alpha(max)) largely depended on the counterion species, and it was in the order K(+) < Na(+) < TMA(+) approximately Li(+). This behavior was well characterized by the specific features of each ion: the alpha(max) map could be well superimposed in the Stokes radius-crystal ion radius relationship of counterions. The alpha(max) dependence on Stokes radius was very similar to that of the B coefficient by Jones and Dole except in the case of Ca(2+). In principle, the smaller the value for B, the smaller alpha(max), indicating that a water structure breaker such as K(+) can more easily destroy the colloidal crystal structure. In other words, the effect of the counterion species on colloidal crystal stability follows the Hofmeister series. Including Ca(2+), the relationship was linear for the alpha(max) values plotted as a function of the limiting equivalent conductivity of small ions. A counterion with larger conductivity would be a stronger breaker for the colloidal crystal structure.     

Extensive quinoidal oligothiophenes with dicyanomethylene groups at terminal positions as highly amphoteric redox molecules

A series of highly extensive quinoidal oligothiophenes carrying a dicyanomethylene group at both terminal positions is synthesized. As the quinoidal structures extend, they have highly amphoteric abilities and show strong electronic absorptions in the visible to near-infrared region. The higher homologues, quinquethiophene and sexithiophene, exist as equilibrium mixtures with the biradical species.     

Photochromism of single crystals composed of dioxazolylethene and dithiazolylethene

Although dioxazolylethene 1a did not show any photocoloration in the single crystalline phase, 1a displayed photochromism in the mixed crystal containing both 1a and dithiazolylethene 2a ; the mixed crystal changed color from colorless to red, orange, and yellow upon irradiation with light of appropriate wavelengths.     

Experiments on the propagation of lower hybrid waves in a toroidal plasma

The propagation of the lower hybrid waves is investigated in a toroidal afterglow plasma by using a pair of the half-turned strip lines. It is confirmed that experimental results of propagation in a toroidal plasma well agree with calculated ones from the cold plasma theory.     

Bilocal field model of mesons and its spectroscopy

Zeitschrift für Physik C Particles and Fields - We present a bilocal field theory as an extended, quark model of mesons. The internal equation of motion with the covariant-harmonic interaction...     

Elastic scattering of 56 MeV polarized deuterons on 4He

The differential cross section and the vector and tensor analyzing powers A_y, A_xx, A_yy and A_xz were measured for the d-⁴He elastic scattering at 56 MeV. The measurement of A_xz was performed using a deuteron beam polarized in the horizontal plane. An optical-model analysis of the experimental data was carried out. The magnitude of the tensor analyzing powers could not be reproduced without the tensor potential. By including the T_R type tensor potential, the optical-model calculations give a reasonable reproduction of the experimental data at θ_c.m. < 120°. The obtained T_R tensor potential was much stronger than that predicted by the folding model. The strength of the real T_R potential was roughly in accordance with that obtained from the optical-model analysis of d-⁴He elastic scattering at 20.2 MeV.