Theory for photoinduced structural phase transitions

A general concept for photoinduced structural phase transitions is developed in terms of the hidden multistability of the ground state and the proliferations of optically excited states. Taking the ionic→neutral (I - N) phase transition in the organic charge transfer crystal, TTF—CA, as a typical example for this type of transition, we, at first, theoretically show an adiabatic path of this transition, which starts from a single charge transfer exciton in the ionic phase, but finally reaches a neutral domain with a macroscopic size. In connection with this I—N transition, the concept of the initial condition sensitivity is also developed so as to clarify experimentally observed nonlinear characteristics of this material. In the next, using a more simplified model for the many-exciton system, we theoretically study the early time quantum dynamics of the exciton proliferation, which finally results in the domain formation of a large number of ex-citons. For this purpose, we derive a stepwise iterative equation to describe the exciton proliferation, and clarify the origin of the initial condition sensitivity.     

A thin and compact compound-eye imaging system incorporated with an image restoration considering color shift, brightness variation, and defocus

A compact system of the thin observation module by bound optics (TOMBO) imager based on compound-eye imaging has been constructed to demonstrate its advantages over single-eye imaging systems such as thinner hardware. To reconstruct a high-resolution image from low resolution images captured by the compound-eye optics, we propose an image restoration scheme based on the iterative back-projection algorithm with depth map estimated from the disparities on the captured image. The scheme includes suppression of unit-by-unit color shift caused by the offset microlenses and the color filters on the commercial image sensors and deblurring of defocus by geometrical optics using the depth map. In the experiment, three-dimensional objects were captured by the TOMBO imager and reconstructed with the scheme. After the processing, the power spectrum of the captured image was improved by up to 19 dB, and the power spectrum of the effect of the color shift was reduced by 7 dB.     

Stereocontrolled construction of a spiro fused bicyclo[2.2.2]Octane ring system by the intramolecular double michael reaction

The lithium enolate from the cyclohexenone (8) possessing the α, β-unsaturated ester moiety caused an intramolecular double Michael reaction to produce stereoselectively the spiro fused bicyclo[2.2.2]-octane (10).     

Studies on the syntheses of heterocyclic compounds. Part DCLV.. Two stereoisomers of 1-benzyl-5-hydroxy-6-(4-methoxybenzyl)-4,5-dimethylpiperidin-2-one

The stereochemistry of two diastereoisomers of 1-benzyl-5-hydroxy-6-(4-methoxybenzyl)-4,5-dimethylpiperidin-2-one (IV), which is an intermediate for synthesis of pentazocine (I), was elucidated.     

The photodissociation of alkali halides in air—acetylene flame as studied by molecular absorption spectroscopy

Absorption spectra of alkali salts, which were aspirated into the air—acetylene flame, have been investigated in the u.v. and visible region, where a conventional atomic absorption spectrometer with an analog data processing system was used for obtaining the spectra. Molecular bands which arose from the alkali halides and oxides were observed along with atomic lines. In the case of lithium, only molecular absorption bands of lithium oxide were observed in the flame, even when lithium halides were aspirated. These molecular absorption bands can be interpreted in terms of photodissociation processes of the alkali halides and oxides produced in the flame.     

Monodictyquinone A: a new antimicrobial anthraquinone from a sea urchin-derived fungus Monodictys sp

A new antimicrobial anthraquinone, 1,8-dihydroxy-2-methoxy-6-methylanthraquinone, monodictyquinone A (1), was isolated from a culture of a marine-derived fungus of the genus Monodictys which was isolated from the sea urchin, Anthocidaris crassispina, along with three known compounds, pachybasin (2), chrysophanol (3), and emodin (4).