Several aspects of high-resolution spectroscopy of simple free radicals in gas phase are reviewed with particular emphasis on experimental techniques such as microwave spectroscopy, electron-paramagnetic-resonance, laser-magnetic resonance, microwave-optical double resonance with tunable dye lasers, and molecular-beam spectroscopy. Recent technical developments to detect ionic species as well as contributions from and to radio astronomy are also described briefly.
Modulation thresholds for red gratings (632.8 nm) were measured after prolonged viewing of gratings which were of the same or different wavelength (514.5 nm, 488.0 nm and 476.5 nm). The thresholds were significantly elevated by adaptation to gratings of the same or another color. Similarly, spatial frequency tuning curves were also independent of the adapting wavelength. However, thresholds forred gratings were less elevated by adaptation to blue (476.5 nm) gratings thangratings of another color. These results imply the existence of color specific spatial frequency channels, although their sensitivities overlap each other in wavelength and in inhibition mechanisms among such channels. The reduction of threshold elevation for red gratings following adaptation to blue gratings is of special interest. This may be interpreted as a result of (1) the spatial frequency channel maximally sensitive to red gratings having been adapted by response to blue gratings, and (2) the same channel also receiving simultaneous inhibitory inputs from the frequency channel responsible for blue gratings.
Ge polycrystalline films were deposited on fused silica substrates by DC double cathodes sputtering. The electrical characteristics of the films especially the carrier concentration and Hall mobility were measured as a function of target voltage and Ar gas pressure for the substrate temperature of 500°C and film thickness of 2500Å, and their crystalline structure was examined by an X-raydiffractmeter. The Hall mobility of the deposited films increased and the carrier concentration decreased with increasing ratio of Ar gas pressure to targetvoltage. But, the diffraction patterns indicated no remarkable change of film structure. From these results it is considered that by increasing the Ar gaspressure to target voltage ratio i, a decrease of sputtering energy, the defectswhich are due to the bombardment of high energy neutralized Ar atoms and secondaryelectrons scattered from the target during sputtering are decreased and theelectrical properties of the films are improved.
Scattered-light photoelastic technique was applied to the determination of pressure distri-bution at the bottom of the powder bed in a cylindrical container under pressure. The method is free from disturbances due to measuring elements usedin usual methods. Normal stress at the bottom of the powder bed showed a maximum at the center and decreased monotonously along the radial direction. The maximum value of the stress was nearly proportional to the pressure applied on thepowder bed. Normal force at the bottom of the bed, calculated by integratingthe normal stress, agreed with the result of direct measurement obtained by a built-intransducer with a maximum error of 15%.
Department of Applied Physics, Faculty of Engineering, Hokkaido University Effects of hydrostatic pressure on the mechanical properties of Antarctic deep core ice were investigated by the use of a special uniaxial testing machine nstalled in a high pressure cell. The design and construction of the pressure cell as well as of, the testing machine are here described. Hydrostatic pressure up to 100 MPa could be attained and kept for several days' duration in the cell using a hydraulic pump with silicone oil. The testing machine was driven from the outside of the pressure cell by a rod penetrated through its thick wall. Volume change of the inner space of the cell caused by the movement of the driving rod was compensated by the movement of another rod from the opposite direction at the opposite end of the cell. The frictional force exerted on the driving rod at the bore hole in the cell wall was well separated from the real stress generated in a specimen due to its uniaxial deformation. Preliminary compressive tests carried out at 30 MPa revealed that the strength of the deep core ice increased under hydrostatic pressure. This hardening effect is attributed to the shrinkage or closure of air-bubbles and cleavage cracks formed in the relaxation process of the deep core ice.
Small He-Zn hollow cathode laser tubes were constructed and a stable CW laser oscillation has been obtained at 7588 Å laser line in ZnII. Measurements were carried out on the laser output power characteristics and its effect by addition of neon gas and finally the noise in laser light. An increase of almost 50% in laser power has been observed when the mixing rate of neon at the optimum helium gas pressure of 14 Torr. The noise component is 0.2-0.3% of the laser light.