Interfacial crystallization and electronic properties of platinum double salts

Insoluble platinum double salts were crystallized by a novel method involving a solid-liquid interface. The platinum complexes included Magnus Green Salt, MGS ([Pt(NH)₃)₄]²⁺ [PtCl₄]^2–) and PBC ([Pt(bpy)₂]²⁺[Pt(CN)₄]^2–). The crystallization and molecular ordering of MGS and PBC on a Nafion membrane were achieved by controlling the diffusion of the cation and anion components to the solid-liquid interface. The electrical conductivity of the MGS film on Nafion was greatly augmented by oxidizing the polynuclear complex. A device consisting of the PBC film on Nafion, methyl viologen, and triethanolamine displayed photoelectrochromism.     

Charge Transfer in Fullerene-Conducting Polymer Compositex: Electronic and Excitonic Properties

C₆₀ doping into conducting polymer with highly extended π-electron system in the main chain induces remarkable quenching of photoluminescence in conducting polymer and drastic enhancement of photoconductivity. These results can be explained in terms of photo-induced charge transfer between conducting polymer and C₆₀. That is, photoexcited excitons or exciton-polarons on conducting polymer are effectively dissociated at C₆₀ molecules transferring electrons to C₆₀. Photoexcitation of C₆₀ results in the transfer of hole from C₆₀ to conducting polymer. These novel C₆₀ doping effects have been observed not only in conducting polymers with non-degenerated ground state structures but also those with degenerated ground state structure such as di-substituted acetylene polymers with solitonic electronic systems.

Highly effective photo-induced charge transfer has been also observed in conducting polymer/C₆₀ heterojunctions, which are interpreted as donor (D)-acceptor (A) photocell. Based on this finding we have demonstrated an organic photovoltaic cell with D-A double heterojunction, Al/C₆₀/OEP/conducting polymer/TTO, in which OEP is octaethylporphine as an light absorbing antenna molecule. Novel characteristics have also been observed in various other junction devices utilizing C₆₀ doped conducting polymer.

Granular and multiphase superconductivity has been found in C₆₀-conducting polymer-alkali metal composites.

Effect of other type of fullerenes such as C₇₀, modified C₆₀ and C₆₀ polymers, and also effect of C₆₀ doping in polysilanes and their derivatives have also been studied.     

New Lanthanoid Metallofullerenes and their HPLC Elution Behavior

HPLC behaviors of metallofullerenes of 14 lanthanoid elements were studied by use of radiotracers, and the species of some of the metallofullerenes were identified by mass spectroscopy. From the HPLC elution behaviors, 14 lanthanoid elements forming metallofullerenes were found to be grouped into two, namely, Sm, Eu, Tm and Yb as one group and the rest of the elements as another. Some new species of metallofullerenes like La@C₇₄, and M@C_n (M=Eu, Tm, Yb; n=74, 82, 84, 88, 90, 92, 94) have been identified. The observed retention times of metallofullerenes are discussed in terms of the number of carbon atoms of the cage and from consideration of the electron donor and acceptor relation between the fullerene species and the HPLC stationary phases.     

Acoustically scanned low-coherence interrogated simultaneousmeasurement of absolute strain and temperature using highly birefringentfibers

We have utilized a traveling acoustic pulse in a two-mode optical fiber to create a moving beam splitter coupling light from LP₀₁ to LP₁₁ mode. As these optical modes have different group velocities, a variable intermodal delay is generated as a function of acoustic pulse position in the fiber. The device can be used as a receiving interferometer in low-coherence interferometry to scan time delay for carrying out fast extended range absolute measurement using simple analog electronic circuits. With this scanning technique we demonstrate measurement of absolute strain over 1600 με in the temperature range from 20 to 60°C with resolutions of the order of 40 με and 0.7°C, respectively, employing highly birefringent fibers as sensing elements     

Drastic improvement of bioethanol recovery using a pervaporation separation technique employing a silicone rubber‐coated silicalite membrane

A coupled fermentation/pervaporation process for reliable production of concentrated ethanol was studied using ethanol permselective silicalite membranes coated with two types of silicone rubber, KE‐45 and KE‐108, as a hydrophobic material. Ethanol recovery was greatly improved by using a membrane coated with KE‐45 silicone rubber. The recovered ethanol concentration in the permeate was 67% (w/w), and the amount of recovered ethanol from the broth was more than 10 times higher than that using a non‐coated membrane. Succinic acid and glycerol, by‐products created during fermentation, interfered with the pervaporation performance of the coated membrane when used to separate an ethanol/water solution. Copyright © 2003 Society of Chemical Industry     

Interaction Between Intramolecular Vibrations and Low-Lying Excited States of C60

The interaction between the intramolecular vibrations and the low-lying excited states of C₆₀ is investigated. It is found that the h_g mode of the lowest frequency and of the fourth-lowest frequency are strongly coupled with the low-lying excited states.     

Floating Zone Crystal Growth and Phase Equilibria: A Review

The thermal-imaging floating zone technique can be used to grow crystals of yttrium iron garnet (Y₃Fe₅O₁₂), aluminum-doped yttrium orthoferrite (YFe_0.88Al_0.12O₁₂), and magnetite (Fe₃O₄), which represent peritectic compounds, solid-solution crystals, and atmosphere-sensitive materials, respectively. The reactions involved in floating zone crystal growth are explained on the basis of phase diagrams. A review of crystal growth reports, including unpublished findings by the present authors, demonstrates how the crystallization processes, the reaction with the ambient atmosphere, and the composition variation in the obtained crystals can be explained or controlled on the basis of phase equilibrium. The floating zone technique is applicable to a variety of materials and remains a handy tool for materials research; however, its industrial application may be limited.     

The long-term course of spike and wave complexes in the waking EEG of chronic schizophrenics

Nineteen chronic schizophrenics (8 males and 11 females) showed at least one spike and wave complex (SpW) in their rested-awake EEGs during long-term neuroleptic treatment. The age at the first appearance of the SpW ranged from 16 to 60 years, and the duration of neuroleptic medication preceding its appearance was from 1 to 35 years. Two types of SpW waveform were discriminated; one was a diffuse high voltage isolated 3.5-4 Hz SpW complex, and the other a diffuse moderate voltage 5-6 Hz SpW burst. In EEG studies repeated over the long-term, the presence of SpW was transient in 11 cases, intermittent in 5 cases, and continuous in 3 cases. Three patients had generalized tonic-clonic clinical seizures; two of their EEGs did not show SpW until after the onset of seizures. All three responded well to adjunctive anticonvulsant therapy. The other 16 patients exhibited SpW but did not have clinical seizures with or without prophylactic use of anticonvulsants. The SpW in the EEG of chronic schizophrenics might be an indicator of predisposition for seizure, but it is not a good predictor of seizure.     

An Improvement of Herbrand＇s Theorem and Its Application to Model Generation Theorem Proving

This paper presents an improvement of Herbrand＇s theorem. We propose a method for specifying a subuniverse of the Herbrand universe of a clause set S for each argument of predicate symbols and function symbols in S. We prove that a clause set S is unsatisfiable if and only if there is a finite unsatisfiable set of ground instances of clauses of S that are derived by only instantiating each variable, which appears as an argument of predicate symbols or function symbols, in S over its corresponding argument＇s sub-universe of the Herbrand universe of S. Because such sub-universes are usually smaller （sometimes considerably） than the Herbrand universe of S, the number of ground instances may decrease considerably in many cases. We present an algorithm for automatically deriving the sub-universes for arguments in a given clause set, and show the correctness of our improvement. Moreover, we introduce an application of our approach to model generation theorem proving for non-range-restricted problems, show the range-restriction transformation algorithm based on our improvement and provide examples on benchmark problems to demonstrate the power of our approach.     

VCM design with round coil and axe-shaped magnet for hard disk drive actuator

In this paper, we proposed a novel single-sided magnet voice coil motor (VCM) design that can reduce out-of-plane force. Out-of-plane force of a VCM causes the actuator vibration, which results in settling vibration and acoustic noise. The proposed single-sided magnet VCM consists of a round coil and an axe-shaped magnet. We designed the optimized configuration by using numerical magnetic field simulation and compared its performance with those of a conventional VCM. Torsional moment was reduced by 90% at the worst position of the middle track, and bending moment was reduced by 50% at the worst position of the inner track compared with a conventional VCM. Rotational moment in our VCM was almost the same as that of the conventional one. We manufactured an actuator with the new design VCM and confirmed that the new single-sided magnet VCM shows a good performance as expected, although its magnet volume and coil resistance were almost the same as a conventional design. The measured frequency response of the actuators from the coil current to the head displacement showed that the coil torsional mode vibration of the proposed VCM is reduced remarkably.