Cross-correlation properties of multiply-scattered dichromatic light from flowing colloidal particles

The cross-correlation properties of dichromatic light multiply-scattered by colloidal particles in a uniform flow are studied experimentally. It is shown that the correlation peak value of intensity fluctuations depends on the optical thickness of the sample and the number density of particles, whereas the decay time of cross-correlation functions is almost independent of the characteristics of particle suspensions. This result indicates that the number fluctuations as well as the speckle fluctuations contribute to the temporal variations in the intensity, and that the velocity of the uniform flow is measurable without being affected by the diffusive motion of the scatterers. The effect of wavelength difference is also examined.     

Resistive superconducting transition of vanadium films

The resistive superconducting transition of vanadium films is studied experimentally. The behavior of the resistance is well explained by fluctuation theory. In parallel magnetic fields the pair-breaking parameter increases with the increase of the strength of the magnetic field.     

Nuclear magnetic resonance study of low molecular weight polychlorotrifluoroethylene

The molecular motion of low molecular weight polychlorotrifluroethylene of different molecular weights between 500 and 1300 was investigated by means of broad-line nuclear magnetic resonance measurements. The line width and second moment of the resonant absorption lines were obtained at temperatures from 77 to 300°K. The line narrowing for low molecular weight samples takes place in one step. In samples higher than 900 in molecular weight, however, there appears to be a glass transition process, and the line narrowing tends to occur in three steps. The line narrowing due to local molecular motion becomes observable with increasing molecular weight.     

Application of atomic stereomicroscope to surface science

A stereograph of atomic arrangement was displayed directly on the screen of display-type spherical-mirror analyzer without any computer-aided conversion process for the first time. This stereoscopic photograph enables viewing three-dimensional atomic arrangement. This technique was realized taking advantage of the phenomenon of circular dichroism in photoelectron angular distribution. The azimuthal shifts of forward focusing peaks in a photoelectron angular distribution taken with left and right helicity light in a special arrangement are the same as the parallaxes in a stereo view of atoms. Hence a stereoscopic recognition of three-dimensional atomic arrangement is possible, when the left eye and the right eye respectively view the two images obtained by left and right helicity light simultaneously.     

Diffusion of symmetrical and spherical solutes in protic,aprotic, and hydrocarbon solvents

The diffusion coefficients of a series of symmetrical tetraalkyltins (tetramethyltin, tetraethyltin, tetrapropyltin, tetrabutyltin, tetradodecyltin) of the gases argon, krypton, xenon, methane, and tetramethylmethane and of carbon tetrachloride and tetraethylmethane in hexane, decane, and tetradecane at 25°C have been determined using the Taylor dispersion technique. Diffusion coefficients for the gases in acetone, 2-propanol, 1-butanol, and 1-octanol were also determined. Deviations from the predictions of Stokes' law were found to be large, and the magnitude of the deviation can be directly related to solute size. The predictions of the Hubbard-Onsager equation were tested using the diffusion data.