The aggregations or crystals of metal-complex dye (C. I. Acid Yellow 161) on wool fibre

Summary The visible absorption spectra of dye crystals and the cross-section of wool fibre dyed with metal complex dye (C. I. Acid Yellow 161) were measured by means of a microspectrophotometer. The spectrum of crystal showed sharp and high maximum at 410 nm referred to as the peak from single crystal of the dye. The spectrum of the cross-section of dyed fibre showed two peaks of 410 nm (crystal-band) and 435 nm (monomeric state of the dye). Also, the electron diffraction pattern of the cross-section of dyed wool fibre showed the reflection ring of chromium. These results suggested that the dye should be present in the wool fibre in the monomeric, aggregate or crystalline state.

---

Zusammenfassung Mit Hilfe des Mikrospektrophotometers wurden die Absorptionsspektren im Sichtbaren von Farbstoffkristallen und von Querschnitten der mit Metallkomplex-Farbstoff (C. I. Acid Yellow 161) gefärbten Woll-Fasern gemessen. Die Kristall-Spektren zeigen ein scharfes und hohes Maximum bei 410 nm, das der Bande des Farbstoffkristalls zugeordnet werden muß. Die Spektren der Querschnitte gefärbter Fasern zeigen zwei Banden: seine bei 410 nm (Kristallbande) und eine bei 435 nm (Monomerbande). Auch zeigen die Elektronenbeugungen an Querschnitten gefärbter Fasern die Ring des Chromes. Dies läßt vermuten, daß in den Wollfasern Monomeres, Aggregate oder Kristalle des Farbstoffs existieren.

     

Electronic structure of TiH2

The electronic structure of TiH₂ has been studied using the augmented-plane-wave method and the LCAO interpolation. The density of states and its orbital components show that the conduction band is Ti d-like and that the valence band is largely derived from the hydrogen orbitals with small Ti 3d hybridization. The electronic charges on the hydrogen atom are ～ 1.5 as compared to 1.6–1.7 of the rare-earth metal hydrides.     

Angle-resolved photoemission spectra of 2H-NbSe2

Angle-resolved photoemission measurements have been made on the metallic layer compound 2H-NbSe₂. From the results, E vs k_∥ dispersion curves have been obtained along two principal symmetry directions in the Brillouin zone. The experimental energy bands are found to be in good agreement with the results predicted by one-dimensional density of initial states along k_⊥.     

Low-energy charge-density excitations in MgB2: Striking interplay between single-particle and collective behavior for large momenta

A sharp feature in the charge-density excitation spectra of single-crystal MgB2, displaying a remarkable cosinelike, periodic energy dispersion with momentum transfer (q) along the c* axis, has been observed for the first time by high-resolution nonresonant inelastic x-ray scattering (NIXS). Time-dependent density-functional theory calculations show that the physics underlying the NIXS data is strong coupling between single-particle and collective degrees of freedom, mediated by large crystal local-field effects. As a result, the small-q collective mode residing in the single-particle excitation gap of the B pi bands reappears periodically in higher Brillouin zones. The NIXS data thus embody a novel signature of the layered electronic structure of MgB2.