Stereoselective total synthesis of bazzanene

3azzanene, the stereoisomer of trichodiene, isolated from a liverwort was synthesized with complete stereoselectivity in 8 steps (12% yield) starting from a known bicyclo[2.2.2]octane derivative.     

Electrical properties of calcia-doped ceria with oxygen ion conduction

The electrical conductivity of sintered specimens of (CeO₂)_1−x(CaO)_x was investigated by employing a standard four-probe dc technique as a function of temperature between 400°C and 900°C, composition from 0.10x0.80, and oxygen partial pressure from 10⁻¹⁸ to 1 atm. The temperature and composition dependence of the emf have been carried out with a concentration cell. X-ray diffraction studies indicated that a cubic fluorite crystal remained in all specimens studied, although the solubility limit of CaO in CeO₂ was assumed to lie close to 23 mol% from the change of the lattice constant. The magnitude of the conductivity decreased slightly with increase of the dopant concentrations up to x=0.50. The conductivity of these specimens was about 100 times larger than that of calcia-stabilized zirconia at 600°C with a smaller activation energies of 0.83–0.89 eV. With further increasing dopant concentrations, the magnitude of the conductivity was found to decrease remarkably. With an increase in the dopant concentration, the domain of primarily ionic conduction extended to a lower partial pressure. The conductivity of (CeO₂)_0.50(CaO)_0.50 was found to be primarily ionic down to 10⁻¹² atm even at 900°C. These results indicate that CaO-doped CeO₂ may be more an attractive candidate for fuel cells and other applications.     

Chiral,Thermally Irreversible and Quasi-Stealth Photochromic Dopant to Control Selective Reflection Wavelength of Cholesteric Liquid Crystal

A chiral and thermally irreversible photochromic fulgide derivative incorporating an (R)-binaphthol unit in its acid anhydride moiety was used for the photoswitching of the pitch length of cholesteric liquid crystals. Since the absorption maximum wavelengths of both thermally stable photoisomers are nearly in the UV region (quasi-stealth photochromism), it can be exposed to visible light without inducing photochromic reactions. Therefore, when the photoswitching molecule is added to a permanent cholesteric liquid crystal whose reflection light wavelength is in the visible region, the UV light-induced photochromic reaction of the photoswitching molecule changes the wavelength of the reflection light in the visible light region. We have succeeded in regulating the color of cholesteric liquid crystalline cells between red and blue upon UV light irradiation. Attempts to introduce this system in polymer dispersed cholesteric liquid crystals are also described.     

Complex wavefront reconstruction of digital in-line holography with a spatial radial carrier

We propose a method for reconstructing a complex wavefront from a single-shot in-line digital hologram with a spatial radial carrier. In the proposed method, the spatial radial carrier is generated by a point source that is located in front of an image sensor, as close as possible to the sensor with the condition that the Nyquist limit is not exceeded. A signal processing method employed for elimination of the zeroth-order and conjugate wave components is presented. Computer simulations and optical experiments are performed to verify the proposed method.     

Electronic structures of single-walled carbon nanotubes encapsulating ellipsoidal C70

The molecular orientation of ellipsoidal C(70) in single-walled carbon nanotubes (SWCNTs) depends on the tube diameter (d(t)). Photoluminescence (PL) studies reveal that the fullerene encapsulation effects on the optical transition energy of SWCNTs are significantly different for C(70) and C(60) at d(t) = 1.405-1.431 nm. This indicates that the transition from the "lying" alignment to the "standing" alignment occurs at d(t) ≈ 1.41 nm and the electronic states of SWCNTs are very sensitive to the interspacing between the encapsulated molecules and the SWCNTs. The present findings suggest that the electronic structure of SWCNTs is tunable not only by alternating the encapsulated molecules but also by controlling their molecular orientations, thus paving the way for development of novel SWCNT-based devices.     

Synthesis of manzacidin A and C: efficient construction of quaternary carbon stereocenters bearing nitrogen substituents

An efficient synthetic method for stereoselective construction of asymmetric quaternary carbon stereocenters, bearing nitrogen in the form of Boc-protected allyl amines, has been developed. This methodology is employed in the synthesis of marine alkaloids, manzacidin A and C.     

Improvement in SOFC anode performance by finely-structured Ni/YSZ cermet prepared via heterocoagulation

A novel preparation technique for a nanostructured anode for a solid oxide fuel cell is investigated. By mixing nanometer-sized NiO and YSZ powders in a pH-controlled aqueous media, a fine mixture of nanoparticles is successfully obtained through heterocoagulation. The anode prepared from thus prepared mixture has a large triple phase boundary and shows a great improvement in the anode performance by increasing the electric conductivity and effective surface area.