Gamma-ray spectroscopy of 66Zn and 67Zn and the role of the g92 orbital

Measurements of γ-ray yield functions, γ-γ coincidence spectra and y-ray angular distributions following the ⁶⁴Ni(α, n) and (α, 2n) reactions have been made. Beam energies of 17 to 25 MeV were used. Among the new levels observed, with their proposed spin-parity assignments, are: in ⁶⁶Zn, 3708 keV, (5)⁺; 3896 keV, 5^?; 4812 keV, (7^?); 5110 keV, (8^?); 6417 keV; (10^?); 7516 keV, (12⁺); and in ⁶⁷Zn, 2937 keV, $\text{13}\text{2}{}^{\mathrm{+}}$; 3491 keV, $\text{17}\text{2}$ or $\text{19}\text{2}$; 3492 keV, ($\text{13}\text{2}$(si+)); 4221 keV, ($\text{19}\text{2}$^?); 4631 keV, ($\text{21}\text{2}{}^{\mathrm{+}}$); 4685 keV, ($\text{21}\text{2}$^?). Comparison between the ground-state sequence, 0⁺ to 6⁺, in ⁶⁶Zn and the first $\text{9}\text{2}$⁺ to $\text{21}\text{2}$⁺ levels in ⁶⁷Zn strongly suggests that the latter be described as a g_{$\text{9}\text{1}$} neutron orbital weakly coupled to the ⁶⁶Zn core. Other sequences of high-spin ⁶⁶Zn states are proposed to be formed from two-quasiparticle states containing the g_{$\text{9}\text{2}$} excitation, coupled to the same ground-state sequence.     

A study of87Zr by (α,x n) reactions

The reactions⁸⁴Sr(α,n)⁸⁷Zr and⁸⁶Sr(α, 3n)⁸⁷Zr were used to populate excited states in⁸⁷Zr. The de-excitation of these states was studied by in-beamγ-ray spectroscopy. A number of new high-spin states were observed. Lifetime measurements were also performed. The results are discussed within the frame-works of the shell model and the particle-core coupling model.     

Experimental evidence of distance-dependent diffusion coefficients of a globular protein observed in polymer aqueous solution forming a network structure on nanometer scale

The distance dependence of the diffusion coefficient (DDDC) of a globular protein (cytochrome c) in aqueous hyaluronan (HA) solution, which is a model system for extracellular matrices (ECMs), was measured by a combination of three kinds of spectroscopic measurements of diffusion coefficients, the time and space samplings of which are different. The results of the three methods are plotted against the diffusion distance derived from the consideration of each experimental condition. Due to the characteristic morphology of HA with an effective mesh structure, the proteins showed two extreme diffusion modes: (1) short (<10 nm) diffusion with rare contact with polymer chains; (2) long (>100 nm) diffusion significantly disrupted by polymer chains showing an approximately 30% reduction in diffusion coefficient. The transition from the short diffusion to the long one occurs in a very narrow range (10-100 nm) of diffusion distance and this unique character of HA realizing anomalous diffusion should provide suitable environments for various bioactivities when involved in ECM.     

Evolution inclusions governed by subdifferentials in reflexive Banach spaces

The existence, uniqueness and regularity of strong solutions for Cauchy problem and periodic problem are studied for the evolution equation: where is the so-called subdifferential operator from a real Banach space V into its dual V*. The study in the Hilbert space setting (V = V* = H: Hilbert space) is already developed in detail so far. However, the study here is done in the V–V* setting which is not yet fully pursued. Our method of proof relies on approximation arguments in a Hilbert space H. To assure this procedure, it is assumed that the embeddings are both dense and continuous.     

Burning velocity of triple flames with gentle concentration gradient

We investigated the local flame speed of a two-dimensional, methane-air triple flame in a rectangular burner. The velocity fields and the concentration profiles were measured with particle image velocimetry and the Rayleigh scattering method, respectively. There was a requisite combination of initial velocity and initial concentration gradient for consistency of the local concentration gradient at the leading edge of the flame. In these cases, the flame curvatures were also consistent. Accordingly, the burning velocity, defined as local flow velocity at the triple point, was determined by the flame curvature. The burning velocity increased with increasing flame curvature, when the curvature was near zero. After that, the burning velocity decreased with increasing curvature. The peak value thus exceeded the adiabatic one-dimensional laminar burning velocity. Comparing the effects of the measured flame stretch rate on the flow strain κ_s and flame curvature κ_c, κ_s is larger and increases more rapidly than κ_c for flame curvatures satisfying 1/R_f < 250 m⁻¹ and then becomes constant while κ_c still increases for 250 m⁻¹ < 1/R_f, so that κ_c becomes much larger than κ_s. There is also a peak in burning velocity at roughly the transition in flame curvature specified above. Therefore, the burning velocity for a low concentration gradient correlates with the flame stretch rate.     

Modifications of epitaxy in evaporated films by electric charge effects

Modifications of epitaxy in Ge, Si, CdS, β-Sn, and α-Fe films, 100–600 Å in thickness, evaporated onto air-cleaved and vacuum-cleaved (001) NaCl substrates under electron bombardment (∽10¹⁵ electrons/cm² sec, at 200–400 V) or an electric field (dc 100–300 V/cm) applied to the substrate surface were investigated by reflection electron diffraction, transmission electron microscopy and selected-area diffraction. Results indicated that epitaxial temperatures of Ge and Si films were considerably lowered, and a monocrystalline β-Sn film was produced by the application of electron bombardment. The application of electric field resulted in the formation of an epitaxial cubic CdS phase, and a single orientation in an α-Fe film. These results are discussed in terms of current speculation concerning the electric charge effects on alkali halide substrates.     

Complexation of americium(III) with humic acid by cation exchange and solvent extraction

Complexation of Am(III) with humic acid was studied at various pHs in 0.1M NaClO₄. The stability constants of the Am(III)—humate complexes were determined by a cation-exchange method. The values of log₁ and log₂ increased slightly with increases of pH from 4 to 6 and were found to be 6.9 and 11.6, respectively, at a pH of 5. Markedly larger values than these were obtained by a solvent extraction method. This discrepancy was also revealed by summarizing data from several literature sources. It is very likely that this can be ascribed to decreases in either humic acid and/or the extractant from the extraction system due to humate interactions at the aqueous-organic interface.This revised version was published online in November 2005 with corrections to the Cover Date.