A nonaspherical cell-like 2-dimensional simply connected continuum and related constructions

We prove the existence of a 2-dimensional nonaspherical simply connected cell-like Peano continuum (the space itself was constructed in one of our earlier papers). We also indicate some relations between this space and the well-known Griffiths' space from the 1950s.     

Highly polarized very cold neutrons through a permanent magnet quadrupole

We obtained highly polarized very cold neutrons through a quadrupole magnet with a large aperture. When neutrons go through a quadrupole magnet, parallel-spin neutrons are attracted to the magnet axis and anti-parallel-spin neutrons are repelled off the axis. Therefore, the neutrons through a sufficiently long quadrupole magnet have completely parallel-spin. At the downstream of the quadrupole magnet, we placed another quadrupole magnet to divide neutrons into two regions depending on their spin directions. We obtained the neutron polarization from the integrated count of the two regions and found it was 99.88±0.09 (stat.)±0.05 (syst.)%.     

Numerical analysis of 3D vortical cavity flow

The vortical flows of an incompressible fluid in a rectangular three-dimensional container with a large spanwise aspect ratio driven by a moving solid lid are studied using a combined compact finite difference (CCD) scheme with high accuracy and high resolution. The study focuses on the change of the steady flow structures in the cavity with Reynolds numbers ranging from 100 to 850. The results of the flow in the cavity with a spanwise aspect ratio 6.55 show that several stable closed streamlines localized near the symmetric plane are found at Re ≥500, while a closed stable streamline is found near the side wall at Re ≤300. The change of the flow pattern present in this system affects the diffusion properties in the flow but seems to have no qualitative effect on the global flow properties which include energy dissipation in the cavity. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Convenient substitution of hydroxypyridines with trifluoroacetaldehyde ethyl hemiacetal

Thermal substitution of 4‐hydroxypyridine 1 with trifluoroacetaldehyde ethyl hemiacetal (TFAE) leads to a moderate yield of 3‐(1‐hydroxy‐2,2,2‐trifluoroethyl)‐4‐hydroxypyridine 7 in the presence of a catalytic amount of anhydrous potassium carbonate. Under similar conditions, several α‐trifluoromethyl hydroxy‐pyridinemethanols 8–15 are easily prepared from 2‐ or 3‐hydroxypyridines 2–6 .     

Convenient synthesis of 4-tert-butyl 2-ethyl 3-amino-1-benzyl-5-dialkylamino-1H-pyrrole-2,4-dicarboxylate derivatives

Optimization details and limitations of a novel synthetic method of 4-tert-butyl 2-ethyl 3-amino-1-benzyl-5-dialkylamino-1H-pyrrole-2,4-dicarboxylate derivatives are herein disclosed. This synthesis consists of four steps that include a highly selective cyclization, and can be carried out from starting materials to target compounds without column chromatography purification. The high selectivity is controlled by lithium coordination and steric hindrance caused by tert-butyl ester.     

Ultra slim and bendable backlight system with a unified component for liquid crystal display applications

Our research group has developed an ultra slim and bendable backlight system, which was manufactured by a continuous roll-to-roll process, with a unified component for liquid crystal display (LCD). This backlight system, which has a thickness of 0.26 mm, is simply composed of a light guide film and an optically patterned film made of photocurable resin with micro particles, consequently it does not require any additional optical films such as prism sheets or diffuser. In addition, we have developed a new light guide component which is composed of bundled optical fibers in order to collimate light from the light source to the light guide film. We found that the backlight system could be radiated uniformly across the LCD surface whether plane or curved, and we were able to realize an advanced LCD with good flexibility, high efficiency and high productivity.     

Synchrotron X-ray, photoluminescence, and quantum chemistry studies of bismuth-embedded dehydrated zeolite Y

For the first time, direct experimental evidence of the formation of monovalent Bi (i.e., Bi(+)) in zeolite Y is provided based on the analysis of high-resolution synchrotron powder X-ray diffraction data. Photoluminescence results as well as quantum chemistry calculations suggest that the substructures of Bi(+) in the sodalite cages contribute to the ultrabroad near-infrared emission. These results not only enrich the well-established spectrum of optically active zeolites and deepen the understanding of bismuth related photophysical behaviors, but also may raise new possibilities for the design and synthesis of novel hybrid nanoporous photonic materials activated by other heavier p-block elements.     

Effect of doped zinc species on the photocatalytic activity of gallium oxide for hydrogen production

Zn-doped Ga(2)O(3) samples were prepared by a homogeneous precipitation (HP) method, and the local structures of Zn ions and their photocatalytic activities for hydrogen production were examined. In the sample with low doping amount, the Zn(2+) ions substituted for the Ga(3+) ions in the Ga(2)O(3) photocatalyst and enhanced the photocatalytic activity, since they would improve the migration of the photoexcited electrons in the conduction band of the Ga(2)O(3) photocatalyst. In the sample with high doping amount, the Zn ions formed a composite ZnGa(2)O(4) phase in the bulk of the Ga(2)O(3) photocatalyst to decrease the photocatalytic activity in the present reaction.     

Investigation of the Si doping effect in β-Ga2O3 films by co-sputtering of gallium oxide and Si

A transparent electrode of Si doped β-Ga₂O₃ films for solar cells, flat panel displays and other devices, which consists of chemically abundant and ecological friendly elements of gallium and oxygen, was grown on silicon substrates by RF magnetron sputtering using sintered Ga₂O₃ and Si target. The Si composition in the β-Ga₂O₃ film is determined by electron dispersive X-ray spectroscopy. The X-ray photoelectron spectroscopy peak ratio of oxygen over gallium decreases with increasing Si content. It is concluded that Si substitutes for the Ga sites in the β-Ga₂O₃ film.