Strong Correlation between Ferromagnetic Superconductivity and Pressure-enhanced Ferromagnetic Fluctuations in UGe_{2}.

We have measured magnetization at high pressure in the uranium ferromagnetic superconductor UGe_{2} and analyzed the magnetic data using Takahashi's spin fluctuation theory. There is a peak in the pressure dependence of the width of the spin fluctuation spectrum in the energy space T_{0} at P_{x}, the phase boundary of FM1 and FM2 where the superconducting transition temperature T_{sc} is highest. This suggests a clear correlation between the superconductivity and pressure-enhanced magnetic fluctuations developed at P_{x}.

Field-orientation dependence of low-energy quasiparticle excitations in the heavy-electron superconductor UBe(13).

Low-energy quasiparticle excitations in the superconducting (SC) state of UBe_{13} were studied by means of specific-heat (C) measurements in a rotating field. Quite unexpectedly, the magnetic-field dependence of C(H) is linear in H with no angular dependence at low fields in the SC state, implying that the gap is fully open over the Fermi surfaces, in stark contrast to previous expectations. In addition, a characteristic cubic anisotropy of C(H) was observed above 2 T with a maximum (minimum) for H∥[001] ([111]) within the (11[over ¯]0) plane, in the normal as well as in the SC states.

Diffusion-weighted line-scan echo-planar spectroscopic imaging technique to reduce motion artifacts in metabolite diffusion imaging.

Metabolite diffusion is expected to provide more specific microstructural and functional information than water diffusion. However, highly accurate measurement techniques have still not been developed, especially for reducing motion artifacts caused by cardiac pulsation and respiration. We developed a diffusion-weighted line-scan echo-planar spectroscopic imaging (DW-LSEPSI) technique to reduce such motion artifacts in measuring diffusion-weighted images (DWI) of metabolites.

A robust ultrashort TE (UTE) imaging method with corrected k-space trajectory by using parametric multiple function model of gradient waveform.

Ultra-short TE (UTE) sequences with radial sampling make it possible to visualize tissues with very short T2 decay times. The UTE sequence acquires an echo signal from the central to the outer parts of k-space and is very sensitive to small trajectory errors. Therefore, k-space errors caused by imperfections in the gradient system performance, such as gradient delay and waveform distortion, must be corrected.