Spatial variations in larch needle and soil δ15N at a forest–grassland boundary in northern Mongolia

The spatial patterns of plant and soil δ¹⁵N and associated processes in the N cycle were investigated at a forest–grassland boundary in northern Mongolia. Needles of Larix sibirica Ledeb. and soils collected from two study areas were analysed to calculate the differences in δ¹⁵N between needle and soil (Δδ¹⁵N). Δδ¹⁵N showed a clear variation, ranging from ?8?‰ in the forest to ?2?‰ in the grassland boundary, and corresponded to the accumulation of organic layer. In the forest, the separation of available N produced in the soil with ¹⁵N-depleted N uptake by larch and ¹⁵N-enriched N immobilization by microorganisms was proposed to cause large Δδ¹⁵N, whereas in the grassland boundary, small Δδ¹⁵N was explained by the transport of the most available N into larch. The divergence of available N between larch and microorganisms in the soil, and the accumulation of diverged N in the organic layer control the variation in Δδ¹⁵N.     

FT-IR-ATR observation of SiOH and SiH in the oxide layer on an Si wafer

FT-IR-ATR (Fourier transform infrared attenuated total reflectance) technique was used to measure the SiOH and SiH contents in the thermal oxide films grown on Si wafers. It was found that the SiOH groups in the bulk could be eliminated by low temperature annealing, whereas SiOH at the Si/SiO₂ interface could only be removed by high temperature annealing. It was also found that gamma ray irradiation generated SiOH and SiH in the thin oxide film.     

Preparation of CeO2-TiO2 coatings by the sol-gel process

Yellow coatings have been prepared from titanium tetraisopropoxide and cerium chloride by the sol-gel dip-coating process, and the transmittance, chromaticity, thickness and acidic durability of the coating films produced on glass or aluminum were studied. The effects of the pH of the solution on the preparation of the transparent and homogeneous coating films were studied by adding the alkali or acid, and as a result transparent and homogeneous yellow coating films were prepared by dipping the substrate in a solution containing acetic acidic solution. The acidic durability of the aluminum foil was improved by dip-coating the brilliant yellow CeO₂-TiO₂ coating three times.     

Kationische Polymerisation von Phenylbutadien. 4. Mitt. Kationische Copolymerisation von trans-1-Phenyl-1,3-butadien mit Olefin-Monomeren

Ohne Zusammenfassung     

The mirror transition of the Tz = −12 nucleus 59Zn

The mirror transition of the $\text{T}{}_{\mathrm{z}}\text{= ?}\text{1}\text{2}$ nucleus ⁵⁹Zn was studied by using an isotope separator on-line. The half-life and E^max_β⁺ were measured to be 182.0 ± 1.8 ms and 8100 ± 100 keV, respectively. The ft values and the Gamow-Teller matrix elements to the low-lying states of ⁵⁹Cu were determined and compared with the shell-model values. The masses of neutron-deficient Zn isotopes were calculated from the Kelson-Garvey mass relation.     

Kationische Polymerisation von Phenylbutadien. 4. Mitt. Kationische Copolymerisation von trans-1-Phenyl-1,3-butadien mit Olefin-Monomeren

Ohne Zusammenfassung     

Acyclic,Linear Oligo‐meta‐phenylenes as Multipotent Base Materials for Highly Efficient Single‐layer Organic Light‐emitting Devices

Oligo‐meta‐phenylenes have been designed and synthesized as multipotent base materials of single‐layer organic light‐emitting devices. Simple molecular structures of oligo‐meta‐phenylenes composed of linear phenylene arrays benefited from the wealth of modern reactions available for biaryl couplings and were concisely synthesized in a series. Structure‐performance relationship studies with the first seven congeners revealed key features important for the multipotent materials in single‐layer devices. As a result, highly efficient phosphorescent electroluminescence was made possible in a highly simplified device architecture comprising one‐region, single‐layer configurations. Detailed investigations with hole‐only devices disclosed that the hole mobility was effectively retarded by potent materials, which should facilitate hole/electron recombination for electroluminescence.     

Distinction of absolute configuration at C-22 of C-23-hydroxyspirostane and C-23-hydroxyspirosolane glycosides

It has been revealed that the absolute configurations at C-22 of 23-hydroxyspirostane and 23-hydroxyspirosolane could be unambiguouly judged by the (1)H- and (13)C-NMR spectroscopies.