No abstract

Summary:His bundle electrograms were recorded in 8 rats by a signal averaging technique using the Takayasu vectorial lead system. Animals were anesthetized and placed in the prone position. The polarity of three orthogonal leads were: the X axis, from right to left; the Y axis, from top to bottom; the Z axis, from back to front. Potentials from the X, Y, and Z leads were amplified by 20,000 with high-pass 12 dB/octave filtering at 80 Hz, and signal averaging of 2000 beats was performed at a sampling interval of 100 ps. The His bundle potential could be clearly defined in all 8 rats. The mean amplitude of the His potential was larger in the X-axis (23.6f9.2pV) or the Y-axis (28.4k 14.5pV) than the Zaxis lead (1 1.5 f 8.6pV). Directions of the His potential vectors were to the left in 5 of 8 rats (62.5%), to the caudal in 4 of 6 rats (66.7%), and to the dorsal site in 6 of 8 rats (75.0%). This vectorial lead system, devised in accordance with McFee and Johnston's theory on lead field, was useful for recording His bundle electrograms.

We have constructed a drift tube with a movable ion source and measured the mobilities and longitudinal diffusion coefficients for K+ ions at 303 °K in N2 and at 305 °K in Ar in the pressure range 0.3–5.0 Torr, over the E/N range 4–346 Td in N2 and 3–320 Td in Ar. The zero-field reduced mobilities for K+ ions in N2 and Ar were determined to be 2.50±0.03 and 2.63±0.03 cm2/V sec, respectively. Both values are in excellent agreement with the values reported by Elford and Milloy. When our data are compared with the values obtained by Thomson et al. in N2 and the values obtained by James et al. in Ar over the entire E/N range, we find that the mean deviations are about 1.7%, independent of gas species and E/N. Our zero-field reduced mobilities are about 1.2% lower in both cases than the values compiled by Ellis et al. It is concluded that the discrepancy is due to a systematic error and is not caused by clustering reactions. The mean values of NDL over the E/N range 4–7 Td in N2 and 5–10 Td in Ar were found to be 1.96×1018 and 2.09×1018 cm−1 sec−1, respectively. Both values are about 7% higher than the values calculated from our mobility data by the generalized Einstein relation and from the same parameters reported by Pai et al.

No abstract

The energy dependence of the clustering reactions of Li+ ions with Ar, Kr, and Xe has been measured in the pressure range 2-4 Torr using a drift tube without mass spectrometer. The energy (center of mass) of the Li+ ions was varied over the range 41-67 meV in Ar, 43-129 meV in Kr, and 48-207 meV in Xe. The energy of the cluster ions was varied over the range 40-44 meV in Ar, 40-48 meV in Kr, and 40-43 meV in Xe. All the gases were maintained at room temperture. It is found that the forward rate coefficients are inversely proportional to the ion energy in all cases. The backward rate coefficients increase rapidly with increasing cluster ion energy. Arrhenius plots of the backward rate coefficients gives the activation energy as 0.34 eV in Ar, 0.45 eV in Kr, and 0.49 eV in Xe.

The distribution equilibria of thenoyltrifluoroacetone (TTA) and its scandium chelate between aqueous solutions with an ionic strength of 0.1 and ketones at 25°C have been studied. The distribution of TTA was correlated with the solubility parameters of the ketones and the correlation between the distribution coefficients of TTA and those of scandium chelate was confirmed. The characteristic properties of ketones were discussed in comparison with those of other oxygen containing solvents.

In order to obtain mono-dispersed Fe NPs with high saturation magnetization, quantitative analysis method to investigate the growth dynamics of the Fe NPs synthesized by a conventional thermal decomposition method has been developed. As a result, fast nucleation process promotes formation of ~4 nm of initial nucleus with a non-equilibrium phase, resulting in low saturation magnetization. And slow particle growth with atomic-scaled surface precipitation mode (< 100 atoms/(min·nm 2 )) can form the growth layer on the surface of initial nucleus with high saturation magnetization (~190 emu/g Fe ) as an equilibrium a phase of Fe. Therefore, higher stabilization of small initial nucleus generated just after the injection of Fe(CO) 5 should be one of the key issues to achieve much higher M s of Fe NPs.

A new type of drift tube was designed and constructed for the study on the behavior of slow ions in gases. The guard ring, made up only of an aluminous porcelain tube, is different from those of conventional thin or thick types. Thick-film resistor for microcircuits was coated over the inner surface of the tube. With this guard ring a new swarm experiment was carried out: the drift distance scanning method. Spectra representing the spatial distribution of ions for fixed drift times were obtained. Mobilities and longitudinal diffusion coefficients of K+ ions in oxygen were measured in a trial and compared with the data obtained by a conventional analysis of the arrival time spectra.