Crystal Structure of a Lithium Ion-Conducting Perovskite La2/3−xLi3xTiO3 (x=0.05)

The crystal structure of a lithium ion-conducting perovskite La_0.62(2)Li_0.16(1)TiO_3.01(3) obtained by furnace-cooling was refined by the Rietveld method using neutron-diffraction data at room temperature and 77 K. The adopted space group was Cmmm (No. 65). The anti-phased tilts of TiO₆ octahedra along the b-axis in addition to alternative arrangement of La ions along the c-axis was confirmed. The position of Li was refined to be off-centered and in two equivalent positions in an A-site. The obtained structural information implies that the lithium ion conduction among A-sites occurs in the vicinity of La-poor layers two-dimensionally rather than three-dimensionally in this compound.     

Restricted hydration structures of Rb and Br ions confined in slit-shaped carbon nanospace

Hydration structures of "nanosolutions" around both cation and anion for rubidium bromide confined in nanospaces (pore width = 1.1 nm) of activated carbon fiber were determined with EXAFS measurements and related analysis. The analytical results indicate that the ionic solutions confined in hydrophobic nanospaces tend to form an incomplete dehydration structure, because of the spatial restriction by the nanospace and capturing water molecules in the ordered structure.     

Synthesis of dl-guinesines and related compounds

Guinesines A, B and C were synthesized starting from 1,3-bis(benzylthio)-2-propanone and N-methyl-2,2-diethoxypyrrolidine.     

Recognition of hepatotoxic homologues of Microcystin using a combination of selective adsorption media

Microcystin, a hepatotoxin produced by cyanobacteria, was chromatographically discriminated with newly prepared selective adsorption media. Since the name Microcystin refers to up to 70 different homologues, we have developed a novel technique to prepare selective recognition sites, based on the "Fragment Imprinting Effect". The homologues of Microcystin can be individually discriminated from each other by antigen-antibody assay as well as by C18-based HPLC. This is mainly due to differences in the three dimensional structure of Microcystin homologues; however, differences in toxicity are relatively small among the homologues. Therefore we have to measure the total amount of Microcystin homologues present to determine contamination by Microcystins. We have demonstrated the first group recognition for Microcystin homologues through combination of two different selective adsorption media prepared by a fragment imprinting technique.     

Analysis of concentration characteristics in ultrasonic atomization by droplet diameter distribution

The droplet diameter distribution and concentration characteristics in ultrasonic atomization were experimentally studied. The samples were aqueous solutions of methanol, ethanol and 1-propanol. The diameter distribution of atomized droplets showed the normal distribution, and the median diameter and standard deviation were expressed by means of the ultrasonic condition and the liquid properties. The concentration characteristic in ultrasonic atomization was analyzed by using the model of shell and core to the atomized droplet, where the former and latter consist of solute and solution, respectively. The value, which was surface solute amount in droplet multiplied by the molecular volume, increased with increasing solute molar fraction in bulk liquid and was independent of alcohol kinds. The rate of accompanying liquid and the solute molar fraction in accompanied liquid were estimated from the diameter distribution and the surface solute amount in droplet.     

Behavior of Ultrafine Particles generated from organic vapors by corona ionizers

This paper reports an experimental study on the stability, coagulation and diffusion of molecular clusters and ultrafine particles generated from organic vapors by corona ionizers. Upon leaving the ionizer, particles are made to flow within several types of vessels: depending on the specific geometry of the flow system, clusters either coagulate into large particles or are deposited on the walls. Particles larger than 4nm and molecular clusters penetrate through a wire-screen type diffusion battery, but particles in the size range between 2 and 4nm are collected. Among the organic compounds tested (aromatics, alcohols, ketones and others), only aromatic compounds appear to yield unstable clusters which grow into detectable particles (>2nm) through Brownian coagulation. The other compounds either do not undergo the gas-to-particle conversion process or are too small to be detected. Furthermore, the presence of moisture seems to be of fundamental importance in the particle generation phenomenon. The addition of alcohols to the vapor mixture inhibits particle formation.     

Analysis of the peptides (Prp106-126, MSI-78A,and Oxaldie 1) with the same biological activity by discrete Fourier transform: toward a selection rule in ligand-receptor interaction

Here, we first report a novel method in which the "desired cross-spectrum" of the peptides Prp106-126, MSI-78A, and oxaldie 1 with the same biological activities is obtained by the multiplication of two cross-spectra derived from the RNA sequence and from the cognate amino acid sequence by discrete Fourier transform (DFT), respectively. Based on a well-known method reported previously, we investigated the cross-spectrum by the multiplication of two of three desired cross-spectra. As a result, we found that one prominent peak occurring in the three cross-spectra showed the same frequency when a binary scale was used as a parameter of nucleotide or amino acid in the analysis. Moreover, we examined the relationship between a binary scale and other physicochemical ones. Almost the same results could be reproduced when the absolute electronegativity scale (or the absolute hardness one) was used, but not in the case of the hydrophobic or electron-ion interacting potential scale reported previously. This indicates that either the absolute electronegativity scale (or the absolute hardness one) or a binary scale, or both is very useful in extracting the information desired for various proteins by the present method from the amino acid and the RNA sequence.     

Mechanically Strain-Induced Modification of Selenium Powders in the Amorphization Process

For the fabrication of particles designed in the nanoscale structure, or the nanostructural modification of particles using mechanical grinding process, selenium powders ground by a planetary ball mill at various rotational speeds have been investigated. Structural analyses, such as particle size distributions, crystallite sizes, lattice strains and nearest neighbour distances were performed using X-ray diffraction, scanning electron microscopy and dynamical light scattering.By grinding powder particles became spherical composites consisting of nanocrystalline and amorphous phase, and had a distribution with the average size of 2.7 m. Integral intensities of diffraction peaks of annealed crystal selenium decreased with increasing grinding time, and these peaks broadened due to lattice strains and reducing crystallite size during the grinding. The ground powder at 200 rpm did not have the lattice strain and showed amorphization for the present grinding periods. It indicates that the amorphization of Se by grinding accompanies the lattice strain, and the lattice strain arises from a larger energy concerning intermolecular interaction. In this process, the impact energy is spent on thermal and structural changes according to energy accumulation in macroscopic (the particle size distribution) and microscopic (the crystallite size and the lattice strain) range.