Ordering of the three-dimensional Heisenberg spin glass in magnetic fields

Spin and chirality orderings of the three-dimensional Heisenberg spin glass are studied under magnetic fields in light of the recently developed spin-chirality decoupling-recoupling scenario. It is found by Monte Carlo simulations that the chiral-glass transition and the chiral-glass ordered state, which are essentially of the same character as their zero-field counterparts, occur under magnetic fields. The implication to the experimental phase diagram is discussed.     

QCD analysis of twist-4 contributions to the g i structure functions

We analyze the twist-4 contributions to Bjorken and Ellis-Jaffe sum rules for spin-dependent structure function g ₁(x, Q ²). We investigate the anomalous dimensions of the twist-4 operators which determine the logarithmic correction to the 1/Q ² behavior of the twist-4 contribution by evaluating off-shell Green’s functions in both flavor non-singlet and singlet case. It is shown that the operators which are proportional to the equation of motion play an important role to extract the anomalous dimensions of physical operators. The calculations to solve the operator mixing of higher-twist operators are given in detail     

Impurity-concentration dependence of internal magnetic field acting on platinum in ferromagnetic iron metal

It was found by perturbed angular correlation that the internal magnetic fields acting on platinum in iron were kept in a definite value for uniform alloy samples with impurity concentration ranging from 2 at% to 0.1 at%. Theg-factor of 355.7 keV level of¹⁹⁶Pt was revised tog=0.335±0.018 using the refined ωτ.     

Optical absorption of small metallic particles

In an extremely small metallic particle in which electron energies take discrete values, a light is absorbed by the surface plasmon which is not decayed by the surface scattering. The usually used relation between polarizability of a particle and electrical susceptibility does not hold.     

Nuclear g-factor of the 172+ isomeric state in 63Cu

The nuclear g-factor of the 4498 keV $\text{17}\text{2}$⁺ isomeric state in ⁶³Cu was measured with the in-bearn perturbed angular distribution method, through the ⁶²Ni(α, p2nγ)⁶³Cu reaction, to be g_exp = 0.184 ± 0.012. This value is in good agreement with a semiempirical g-factor for the three-quasiparticle configuration [π2p_{$\text{3}\text{2}$}(v1f_{$\text{5}\text{2}$}, 1g_{$\text{9}\text{2}$})₇]_{$\text{17}\text{2}$⁺} calculated using the experimental single-particle g-factors of neighbouring nuclei. At the same time the internal magnetic field at the Cu nuclei in Ni metal was obtained to be B_int = ?46.6 ± 1.3 kG.     

Photo-induced magnetophonon resonance in n-InSb at 4.2°K

Spin-flip and two-phonon as well as normal magnetophonon resonance are observed in CO₂-laser-irradiated photoconductivity in n-InSb at 4.2°K. The effects are attributed to the resonant cooling of photo-excited electrons due to optical phonon emission.     

Arsenic metabolism in a freshwater food chain: Blue–green alga (Nostoc sp.)→ shrimp (Neocaridina denticulata)→ carp (Cyprinus carpio)

Bioaccumulation and biomethylation of inorganic arsenic were investigated in a three-step fresh-water food chain consisting of an autotroph (blue- green alga: Nostoc sp.), a herbivore (shrimp: Neocaridina denticulata) and a carnivore (carp: Cyprinus carpio). The autotroph, herbivore and carnivore survived in arsenic-containing water below 1000, 2 and 60 mg As(V) dm^?3, respectively. Bioaccumulation of arsenate by Nostoc sp. was decreased with an increase in the nitrogen concentration of the medium. Arsenic(V) was accumulated from the water phase and part-methylated by the carp, as well as by the algae and shrimp. Arsenic was mostly accumulated in the gut of the carp. The predominant arsenical in the guts was the monomethylarsenic species. Arsenic accumulation via food in the above three-step food chain decreased by one order of magnitude and the relative concentration of methylated arsenic to the total arsenic accumulated increased successively with an elevation in the trophic level. When arsenicals were transferred via the food chain, no monomethylarsenic, or only a trace amount, was detected in the three organisms. Dimethylarsenic in the alga, both dimethyl- and trimethyl-arsenic in shrimp, and trimethyl-arsenic in carp, were the predominant methylated arsenic species, respectively.