Novel Zn1-xMnxSe (x = 0.1-0.4) one-dimensional nanostructures: nanowires, zigzagged nanobelts, and toothed nanosaws

Novel Zn1-xMnxSe one-dimensional nanostructures-straight nanowires (x = 0.1 and 0.3), zigzagged nanobelts (x = 0.4), and toothed nanosaws (x = 0.4)-were synthesized using the chemical vapor deposition method. They all consisted of single-crystalline wurtzite ZnSe crystals, irrespective of the Mn content. In particular, the nanosaws have a unique structure in which double-sided teeth are rooted in the nanowire core and bent so as to align as two parallel rows. The long axis is parallel to the [010] direction, and all of the teeth have the [0001] growth direction. The X-ray diffraction pattern confirms the formation of wurtzite ZnSe crystal and the decrease of the lattice constant owing to Mn doping. The Mn2+ emission at 2.1 eV (appeared below 100 K), originating from the d-d (4T1 --> 6A1) transition, proves the effective substitution of Mn2+ ions at the tetrahedral coordinate sites.     

Photoluminescence of Cd1-xMnxS (x < or = 0.3) nanowires

Cd1-xMnxS (x = 0.1-0.3) nanowires were synthesized by using the chemical vapor deposition method. They all consist of a single-crystalline wurtzite CdS structure with a [010] or [011] growth direction. The X-ray diffraction pattern reveals the contraction of the lattice constants due to the incorporation of Mn. The Mn2+ emission at approximately 2.15 eV, originating from the d-d (4T1 --> 6A1) transition, appears below 50-80 K. Its decay time is in the range of 0.55-1 ms, showing a decrease with increasing Mn content. The Mn doping reduces significantly the decay time of band-edge emission from 590 ps to 20-30 ps. Upon applying magnetic field (up to 7 T), the Mn2+ emission is suppressed and donor-acceptor pair emission becomes dominant, suggesting the energy transfer from the band electrons to the Mn2+ ions.     

Expression of hepatitis C virus nonstructural 4B in transgenic mice

Hepatitis C virus (HCV) is a pathogen that is of great medical significance in chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma worldwide. Although the HCV proteins have been intensively investigated over the past decade, the biochemical functions of the NS4B protein are still largely unknown. To investigate NS4B as a potential causative agent of liver disease, transgenic mice expressing the NS4B protein in liver tissue were produced. The transgenic animals were phenotypically similar to their normal littermates for up to 18 months of age. Our results suggest that the HCV NS4B protein is not directly cytopathic or oncogenic in our transgenic mice model.     

Fatigue-resistant photochromic dithienylethenes by controlling the oxidation state

High fatigue-resistant photochromic dithienylethenes were synthesized by controlling the oxidation state of 1,2-bis(2-methyl-1-benzothiophene-3-yl)perfluorocyclopentene (BTF6) and 1,2-bis(2,5-dimethylthien-3-yl)perfluorocyclopentene (DMTF6).     

Enantioselective radical addition reactions to the C=N bond utilizing chiral quaternary ammonium salts of hypophosphorous acid in aqueous media

An enantioselective addition of alkyl radicals to glyoxylate oxime ether mediated by Cinchona alkaloid derived chiral ammonium salts of hypophosphorous acid, QP and QDP, has been developed.     

Some classification of surfaces of revolution in Minkowski 3-space

We study the surfaces of revolution with the non-degenerate second fundamental form in Minkowski 3-space. In particular, we investigate the surfaces of revolution satisfying an equation in terms of the position vector field and the 2nd-Laplacian in Minkowski 3-space. As a result, we give some new examples of the surfaces of revolution with light-like axis in Minkowski 3-space.     

Stability of inclined planar flames as a local approximation of weakly curved flames

To evaluate the effect of vorticity usually generated by curved flames on the flame stability, laminar premixed planar flames inclined in the gravitational field is asymptotically examined. The flame structure is resolved by a large activation energy asymptotics and a long wave approximation. The coupling between hydrodynamics and diffusion processes is included and near-unity Lewis number is assumed. The results show that as the flame is more inclined from the horizontal plane it shows more unstable characteristics due to not only the decrease of the stabilizing effect of gravity but also the increase of the destabilizing effect of rotational flow. Unlike the planar flame propagating downward with the right angle to the upstream flow, the obtained dispersion relation involves the Prandtl number and shows the destabilizing effect of viscosity. The analysis predicts that the phase velocity of unstable wave depends on the Lewis number as well as the flame angle and, especially for unity Lewis number, it is the same with tangential velocity at the reaction zone. For relatively short wave disturbances, still much larger than flame thickness, the most unstable wavelength is nearly independent on the flame angle and the flame can be stabilized by gravity and diffusion mechanism.     

Electrochemical radical arylsulfonylation/semipinacol rearrangement sequences of alkenylcyclobutanols: Synthesis of β-sulfonated cyclic ketones

Electrochemical oxidative radical sulfonylation/semipinacol rearrangement sequences of alkenylcyclobutanols have been developed. The reaction proceeds in an undivided electrochemical cell equipped with platinum plate electrodes employing sodium iodide as a redox catalyst and a supporting electrolyte. This approach is environmentally benign by using shelf-stable arylsulfonyl hydrazides as arylsulfonyl radical precursor and electrons as oxidizing reagents. The present protocol offers a facile way to prepare β-sulfonated cyclic ketone derivatives.     

Combustion of Inert-Gas-Diluted Volatile Organic Compounds Using a Fuel-Rich Pilot Flame and Rotating Arc Plasma

Plasma Chemistry and Plasma Processing - This report proposes a method that uses plasma in combination with combustion to remove very low concentrations of volatile organic compounds (VOCs) that...     

Tunable comb-filter using thermally expanded core fiber and ytterbium doped fiber and its application to multi-wavelength fiber laser

We constructed a novel tunable comb-filter by splicing a commercial Yb³⁺ doped fiber (YDF) between 2 thermally expanded core (TEC) fibers at their core-expanded ends. This structure forms an all-fiber Mach-Zehnder interferometer due to the interference between the core mode and the cladding modes of the YDF. The interference fringes shifts to the longer wavelength region as the YDF is pumped by a 980 nm laser diode (LD). We then demonstrated application of this newly proposed tunable comb-filter to a SOA-based ring laser and obtained multi-wavelength lasing. The lasing wavelengths can be also tuned by pumping the YDF in the proposed comb-filter.