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Optoelectronic property of ZnO epitaxial layer grown by plasma-assisted epitaxy at temperature as low as 340°C using Ti2O3 buffer layer on a-sapphire were studied by low temperature photoluminescence at 10 K comparing to the layers on c-sapphire and a-sapphire without the buffer layer. The near band-edge emission consisting of free-exciton emissions and neutral-donor bound exciton emissions was significantly dependent on the buffer thickness and dominated by the free-exciton emissions in the layer grown on the very thin buffer layer about 0.8 nm, whereas the intense emissions by neutral-donor bound excitons were observed in the ZnO layer on c-sapphire. The structural behavior indicated the donor was originated from the three-dimensional growth of ZnO layer and details of the optoelectronic feature suggested the residual donors were Al and interstitial-Zn.
Lactose powder consisting of α-D-lactose monohydrate and anhydrous β-D-lactose was nondestructively and quantitatively evaluated by
transmission-type Terahertz time-domain spectroscopy (THz-TDS). An absorption
with peak at 39.7 cm-1 (1.19 THz) was assigned to be derived from
anhydrous β-D-lactose, in addition to
the absorptions due to α-D-lactose
monohydrate with peak at 17.1 cm-1 (0.53 THz) and 45.6 cm-1 (1.37 THz). After deconvolution of the spectra using Lorentzian, integrated
intensities of the absorptions with peak at 39.7 cm-1 and 45.6 cm-1 were uniquely dependent on the weight composition ratio of the α-and β-lactose powder. As a
result, the net molar-ratio of the α-and β-lactose in lactose powder could be
precisely evaluated by the integrated intensity ratio. Further, anomer content
in lactose powder extracted from lactose solution was evaluated and the refined
and unrefined features were shown by the evaluation method.
Bulk metallic glasses (BMG) show higher
strength and lower Young’s modulus than SUS 316L stainless steel and Ti-6Al-4V
alloys. This study aimed to investigate the reaction of Zr-based BMG sub-periosteally
implanted on the surface of the rat femur, thereby evaluate the possibility of
the BMG as biomaterials for osteosynthetic devices. Zr65Al7.5Ni10Cu17.5 BMG
ribbons with 10 mm length, 2 mm width and 0.5 mm thickness were implanted
sub-periosteally on the femur surface in three male Wistar rats for 6 weeks.
Systemic effects were evaluated by measuring Cu and Ni levels in the blood, and
local effects were evaluated by the histological observation of the surrounding
soft tissues in contact with the BMG. The reaction of the surface of the BMG was
examined with scanning electron microscopy. No increase of Cu and Ni levels in
the blood was recognized. In the scanning electron microscopy observation, spherical
deposits which were considered as sodium chloride crystals were observed.
Neither breakage nor pitting corrosion was noted. BMG will be a promising
metallic biomaterial for osteosynthetic device that must be removed.