Carbon Dioxide Sensor Mechanism of Porous Hydroxyapatite Ceramics

Hydroxyapatite and Cl⁻ -containing hydroxyapatite powders are prepared and characterized. Reversible substitution of CO^2-₃ for OH⁻ at the surface is presumed to be responsible for the sensor function. The role of Cl⁻, which is necessary to realize the sensor function and is incorporated during soaking treatment, is considered as follows. It may reduce the strain caused by the incorporation of CO^2-₃ (which is larger than OH⁻), and, hence, promote the reversible substitution reaction. This behavior is presumed because Cl⁻ -containing hydroxyapatite samples exhibit sensor characteristics typical of CO₂ without any treatment.     

细化钢铁材料晶粒的原理与方法

细化晶粒是控制金属材料组织结构的最重要、最基本的方法,目前,实际应用的成块材料可获得的最细的铁素体晶粒约为5μm。获得细晶粒的方法有利用相变和再结晶的热处理（或形变热处理）,钢液超速冷却,机械合金化,超细粒子烧结和非晶体结晶等。形变热处理对晶粒细化极为有效,已以实验室规模获得了具有小于或等于1μm的超细晶组织的成块材料。本文以形变热处理为中心,介绍了控制轧制、加速冷却的形变热处理（TMCP）,以及形成微细双相组织、亚晶大角度化等细化晶粒的方法,从金相学角度阐述了细化晶粒的原理和方法的现状及最新进展。     

Distribution of double bonds in thermally degraded polyisobutylene

The distribution of double bonds in thermally degraded polyisobutylene was determined quantitatively by using pulsed Fourier transform ¹H n.m.r. spectroscopic analysis. The double bonds in the degraded polymer did not exist in the interior but at the terminal positions of the polymer chain. These olefins were of the terminal trisubstituted and terminal vinylidene types. The content of the former was much greater than that of the latter. This shows that radical chain transfer predominantly occurs at the methylene hydrogen rather than at the methyl groups of the polymer chain. The average number of double bonds per molecule, f, was greater than 1 and tended to be near 2. Thereby most of the degraded polyisobutylene was shown to have two terminal unsaturations per molecule.     

Hyper-gourd theory: solving simultaneously the mysteries in particle physics, biology, oncology, neurology, economics, and cosmology

The inevitability of various particle masses for hadrons, quarks, leptons, atoms, biological molecules, liquid droplets of fossil fuel and water, living cells including microorganisms and cancers, multi-cellar systems such as organs, neural systems, and the brain, stars, galaxies, and the cosmos is synthetically revealed. This is possible because each flexible particle is commonly generated by a mode in which a larger particle breaks up into two smaller ones through a gourd shape with two lumps. These masses, sizes, frequencies, and diversity dominated by super-magic numbers including the silver ratio, in fractal nature can be derived by the fusion of the quasi-stability principle defined between absolute instability and neutral stability, the indeterminacy principle extended for quantum, statistical, and continuum mechanics, and the spherical Lie group theory. The analyses also result in a new mathematical definition of living beings and non-living systems and further explain the standard network patterns of various particles and also the relation between information, structure, and function, because the proposed theory based on gourds posits a new hyper-interdisciplinary physics that explains a very wide range of scales, while the Newton, Schr?dinger, and Boltzmann equations describe only a narrow range of scales.     

Streptomyces aminopeptidase P: biochemical characterization and insight into the roles of its N-terminal domain

We purified and characterized the aminopeptidase P from Streptomyces costaricanus TH-4 (thAPP). This enzyme has a tetramer structure, a metal-ion preference toward Zn, broad substrate specificity and a narrow pH dependency for activity. The primary structure of thAPP, respectively, exhibits 91% and 65% identity with those of two other APPs-APP I and APP II-from Streptomyces lividans (slAPP I and slAPP II). We next overexpressed the genes encoding thAPP and slAPP II in Escherichia coli and characterized them. Two differences were apparent in their properties: slAPP II formed a dimer, whereas thAPP formed a tetramer; also, the alkaline side pKa for the catalytic action of slAPP II is higher than that of thAPP. Investigation using chimeras of both enzymes revealed that the N-terminal domain is associated with the determination of pKa values for catalytic action and quaternary structure.     

A TEM study on melt-crystallized poly(butylene terephthalate)

A study was made to investigate an optimum condition for ruthenium tetraoxide staining of poly(butylene terephthalate) (PBT) with glass transition temperature as low as ca. 23 degrees C for TEM observation of melt-grown PBT crystals. The morphological study of ultrathin sections prepared based on optimum staining at 25 degrees C for 8 h revealed formation of fringed-micellar crystal nuclei in the early stage and folded-chain fringed-micellar crystals in the later stage of isothermal crystallization at 40 degrees C from melt. The fraction of chain-folded crystals increased with increasing crystallization temperature from the quantitative analysis of crystal thickness in comparison with the reported morphology using the replica method.     

Fabrication of particle-free thin films by laser ablation combined with an electron beam

Particle-free silicon and nickel thin films were successfully fabricated by laser-ablating a melted section of their target surface, which gives a high evaporation pressure at the melting point. The influence of direct evaporation from a melted target was reduced negligibly by melting the target only locally with a focused electron beam (e-beam) and increasing the laser frequency. The silicon films fabricated by the present method, pulse laser deposition of a partially molten target, were able to firmly adhere to the substrates and withstood steel needle scratching, unlike e-beam-evaporated films.     

A self-organization learning algorithm for visuo-motor coordination in unstructured environments

In this paper, we propose a learning algorithm for coordinating a robot system where the movement of an arm is controlled through a stereo camera system. Instead of calibrating the usually complex non-linear transformation between the arm and cameras, the algorithm decomposes the whole transformation automatically into local linear transformations and then makes the linearization map recorded by the arm controller. The linearization is carried out by a learning process based on a Kohonen-style self-organization network. To deal with unstructured environments in which some obstacles exist, some virtual forces are introduced for dealing with the high degree of complexity underlying in the transformation. This work was presented, in part, at the International Symposium on Artificial Life and Robotics, Oita, Japan, February 18–20, 1996     

Novel photoactive aggregates of rhodamine 6G: dequenched and quasi-stable aggregates induced by a dewetting process

Self-organized rhodamine 6G particles prepared by wetting/dewetting process of an ethanol solution on a hydrophilic glass surface exhibits fluorescence without quenching, showing a sharp linewidth of 2nm with a large redshift, which indicates an existence of dye aggregates, similar to J-aggregates, inside the particle. Polarized evanescent field excitation showed that the dye molecule's transition moment along the pi-conjugation was oriented unidirectionally within particles and parallel to the substrate surface. This deduced dye orientation showed correlation between adjacent, but separated, particles and pointed roughly 45 degrees off the dewetting direction. In contrast, the particles of another pi-conjugated NK1420 dye, J-aggregates of which grows easily from an oversaturated solution, showed dye orientation along the dewetting direction preferably, still indicating the effect of self-organization, however based on a different mechanism. An annealing procedure revealed that both aggregates are in quasi-stable states, which is consistent with the rapidness of the dewetting process that may lead to crystallization in nonequilibrium.