Simple analog edge detection circuit based on vertebrate retina

Novel analog edge detection circuits were proposed and fabricated based on the vertebrate retina. The proposed unit circuit is constructed with one photodiode and about eight n-channel metal oxide semiconductor (MOS) transistors. The results with the simulation program with integrated circuit emphasis (SPICE) showed that the one- and two-dimensional array of proposed circuits can detect edge positions with a dynamic range of about 5 decades. The test circuit was fabricated on the breadboard using discrete MOS transistors. The measured results of the test circuit showed that the proposed circuit can detect edge positions. Under the condition that the photodiode used as the input part of the proposed unit circuit is 4,275 μm², the fill factor of the novel circuit is expected to be about 51.7%. The advanced integrated circuit for edge detection which is characterized by a high fill factor, wide dynamic range and low power consumption can be realized by applying the proposed circuit.     

Metal Nanoparticle/Polymer Hybrid Particles: The Catalytic Activity of Metal Nanoparticles Formed on the Surface of Polymer Particles by UV-Irradiation

Summary: Polymer particles decorated with metal nanoparticles were prepared by UV-irradiation of polystyrene latex particles incorporating polymethylphenylsilane (PS/PMPS) and P[S-co-NIPAM]/PMPS particles (NIPAM: N-isopropyl acrylamide) in the presence of metal salts. The metal nanoparticle/polymer hybrid particles were used as a catalyst for the reduction of 4-nitrophenol with NaBH₄. The Pd- and Ag-P(S-co-NIPAM)/PMPS hybrid particles had larger metal nanoparticles and the lower catalytic activity than those of Pd- and Ag-PS/PMPS, respectively. The surface functional group of the polymer particles affected the formation of the metal nanoparticles and their catalytic activity.     

Cobalt-catalyzed annulation of aryl iodides with alkynes

A cobalt-catalyzed approach for the concise synthesis of naphthalenes by the annulation of aryl iodides with alkynes is disclosed. In the reaction, manganese reductant and MeCN solvent are necessary to proceed efficiently, which tolerates various functional groups, for example, boronate ester. Mechanistic investigation indicates that the transformation employs electrophilic aromatic substitution (S_EAr) in the aromatic C–H bond replacement step.     

Generalizing Effective Point Spread Function and its Application to the Phase-Contrast Microscope

Using weak diffraction approximation, we can derive the effective point spread function (EPSF) as the Fourier transform of transmission cross coefficient (TCC) and show that the characteristics of an optical imaging system can be prospectively understood with EPSF. Especially, the halo phenomenon can be more precisely understood.     

Selective surface modification technique for improvement of chromatographic separation selectivity for sugar derivatives.

Highly cross-linked macroporous polymers were prepared utilizing ethylene dimethacrylate as a cross-linking agent, in the presence or absence of methyl-alpha-D-glucoside as a kind of template molecule with methacrylic acid as a functional monomer. After the preparation of the polymers, we applied a high temperature to the cross-linked polymers to study the changes of adsorption properties of the polymers for sugar derivatives including the template molecule utilized. Interestingly, the heat treatment up to 250 degrees C afforded improvement of relative adsorption affinity for several sugar derivatives including the template molecule, while heat treatment up to 150 degrees C did not afford those improvements. The detailed studies including polymers prepared using acrylic acid as a functional monomer instead of methacrylic acid prove that temperatures higher than the Tg temperature of the polymer derived from a functional monomer such as methacrylic acid and higher than the melting point (mp) of the sugar template are necessary to afford the observed improvement of relative affinity based on the surface modification effects through the heat treatment to cross-linked polymers.     

Simple analog-digital motion detection circuit and its application to mobile robot

Simple analog-digital circuits for detecting the motion direction based on the information processing of the vertebrate retina were proposed. A network constructed with an array of proposed circuits was applied to a mobile robot. A test circuit was fabricated using discrete metal oxide semiconductor (MOS) transistors on a breadboard. The measured results of the test circuit showed that the unit circuit can output a motion signal. The motion sensor for detecting the movement direction, which consists of an array of unit circuits, was connected to the microcomputer introduced in the mobile robot. It was clarified that the proposed circuits can control the mobile robot.     

Acoustic properties of double-leaf membranes with a permeable leaf on sound incidence side

Double-leaf membranes with a permeable leaf on the sound incidence side are usually used as roofs in actual membrane-structure buildings. They are modelled as of infinite extent, and their acoustic properties are theoretically analysed. The theory is experimentally validated. The permeability can significantly improve the sound absorption performance at high frequencies, and makes the characteristics similar to those of cavity-backed porous absorbents. At low frequencies the permeability also affects the sound absorption and insulation performance. At middle frequencies, the characteristics changed according to the permeability: a mass-spring peak appears if it is very high, and vanishes if lower. These effects are strongly dependent upon the mass of leaves, flow resistivity, cavity depth, etc. A detailed discussion is also given to shed some light on the mechanism of these effects.     

Rare-earth silylamide-catalyzed selective dimerization of terminal alkynes and subsequent hydrophosphination in one pot

[reaction: see text] Rare-earth silylamides, Ln[N(SiMe3)2]3 (Ln = Y, La, Sm), catalyzed regio- and stereoselective dimerization of terminal alkynes in the presence of amine additives to give conjugated enynes in high yields. The additives played a crucial role to depress the oligomerization and to control the regio- and stereochemistry of the dimerization. Thus, the selectivity for (Z)-head-to-head enynes was increased in the order of tertiary < secondary < primary amine additives. On the other hand, the reversed order was observed for the formation of head-to-tail dimers. When alpha,omega-diynes were subjected to the dimerization, very novel cyclic bisenyne compounds were given through double-dimerization in satisfactory yields. In addition, an application of the system allowed subsequent hydrophosphination of the enynes generated in situ with diphenylphosphine, giving rise to 1-phosphinyl-1,3-dienes as the sole products in excellent yields after oxidative workup.