Recent studies which investigate the mechanism of color vision are reviewed. The con-clusion that there are three different types of receptors is deduced from psychophysical studies of the color matching experiments and the two-color increment threshold experiments. The conclusion is supported by some physiological works such as the microspectrophotometry and the electroretinography. The Hering's prediction that there should exist some antagonistic response pairs such as the red vs green and the yellow vs blue, is also realized by the physiological studies in the form of S-potential and the responses at the ganglion cells. These investigations clearly show that the zone theory proposed by Muller stands for the mechanism of color vision fairly well.
Positive ions of cesium vapors from an auxiliary discharge were produced for the purposes of electron space charge compensation and reduction of the operating temperature of a thermionic converter. At the main emitter temperature of 1200°K, the interelectrode space was filled with cesium plasma by a small auxiliary discharge current and the output current of the converter was found to increase greatly in comparison that without auxiliary discharge. The saturated collector current reached about 60 times as large as the discharge current. Distributions of the plasma density and potential in the power generating space are analyzed, and analytical expressions for the I-V characteristic of converter are derived. A reasonable fit of the theoretical curves to the experimental curves for the I-V characteristics was obtained. Furthermore, it was found that the electrical potential drop in the plasma became negative and the charged particles were carried to the collector by means of diffusion due to a density gradient in the case of the experimental converter. The effects of cesium pressures for the output improvement are also described.
In this paper a modification of the rotating field magnetometer is reported. The principle of the method is based on the fact that a rotating magnetic field applied in the plane of a uniaxially anisotropic film induces a magnetization whose third harmonic component is directly proportional to the anisotropy field Hk. In our experiment the magnetization was detected by the Kerr magneto-optic effect. By this modification, it is possible to measure continuously the rapid change of anisotropy in uniaxial films subjected to a magnetic annealing in the vacuum. Since the absolute determination of the anisotropy field is rather difficult, relative changes of the anisotropy field when the uniaxial strain is applied to the film are measured and compared with other methods. A preliminary experiment on the magnetic annealing is also described,
The discharge and sputtering characteristics of a sputtering system utilizing a double-chathode discharge were studied. The discharge is highly enhanced even when rather low voltage is applied at one of the cathodes, hence high sputtering rate is obtainable. Tantalum films were prepared with this technique and their crystal structures and electrical properties were studied. X-ray analysis showed that α and β tantalum were formed according to the sputtering conditions, and the purest films of each structure had a resistivity of 25 and 180 μΩcm, respectively. Niobium and niobium nitride films were also prepared and were studied with respect to their superconducting properties. The maximum transition temperatures were 9.8°K and 16.0°K, respectively. which were slightly higher than those of the pure bulk materials, nawely, 9.5°K and 15.7°K.
The measuring principle of a movable tube flowmeter is based on the relation between the time rate of momentum change of a body and the force acting on it. Theoretically, the flow rate of a liquid can be measured by a movable tube flowmeter independently of its viscosity. The flowmeter here reported is a kind of movable tube flowmeter, in which the movable tube is a circular cylindrical tube with a coaxial core at its outlet or inlet part and is suspended coaxially between fixed inlet and outlet tubes by bellows. The liquid to be measured flows steadily in the movable tube. The time rate of momentum change of the system composed of the movable tube and the liquid flowing in it is equal to the force acting on the system. The time rate of increase of momentum of the system is equal to that of the liquid, and can be expressed as a function of the flow rate of the liquid. The force acting on the system is expressed in terms of two pressure differences and one force. The experiments with a movable tube flowmeter of core type show good agreement with the theory.
Spatial coherence of a laser light under multi-mode oscillations is investigated from the propagation theory of spatial coherence function. As an example, a confocal type of a Fabry-Perot resonator is considered, in order to evaluate both the degree of spatial coherence and intensity distribution over a laser beam which oscillates with a few of the modes expressed by a Hermite-Gaussian function. It is then shown that a laser light is not always completely spatially coherent even though a radiation pattern takes nearly a Gaussian type. This can be solved, as an example, by studying spatial coherence for a laser oscillation of TEM00 TEM01+TEM10 modes.