Development of copolymer of CR-39 with high sensitivity to low let particles

Several types of copolymers of CR-39 were prepared to find its usefulness as a nuclear track detector of high sensitivity. Track responses of these copolymers were investigated by irradiating energetic ions from proton through Ar. The copolymer of CR-39 monomer with N-isopropylacrylamide (NIPAAm) shows higher sensitivity than that of pure CR-39 for low LET particles such as protons. Preliminary results are reported for the track responses of copolymers (CR-39/NIPAAm) with various contents of NIPAAm as well as the etching properties.     

Acousto-induced structural change in amorphous As2S3

The acoustic flux injection method was applied to amorphous As₂S₃. The velocity and the attenuation constant for shear wave at ～ 100MHz were measured through the observation of the Brillouin scattering of the light beam from a He-Ne laser. The optical transmission around absorption edge was found to change after the injection of acoustic fluxes. It was also found that the sound velocity decreased with increasing injection time of acoustic fluxes and the amount of the change of the sound velocity reached ～ 20% after 10⁵ injections. The changes in the optical transmission and the sound velocity tended to be erased by annealing below the glass transition temperature. These phenomena are considered to be due to structural changes caused by the injection of strong acoustic fluxes.     

Wechselwirkung zwischen Farbstoffen und Polyelektrolyten, 5. Mitt. Einfluß von organischen und anorganischen Salzen auf die Metachromasie von Methylenblau

Ohne Zusammenfassung     

Two-dimensional wave run-up analysis by selective lumping finite element method

A new finite element technique for the analysis of wave run-up is presented in this paper. In this finite element approach, the movement of the shoreline is expressed by that of the nodal points at the wave front, and an auto mesh generation technique is effectively used. The present method is tested by the comparison with the experimental result of a channel with uniform slope, and two numerical examples are reported to show the efficiency of this method. As a final example, the tsunami run-up caused by the 1983 Nihonkai-Chubu earthquake is analysed and compared with actual records of the flooded area.     

Measurement of temporal changes in vocal tract area function from 3D cine-MRI data

A 3D cine-MRI technique was developed based on a synchronized sampling method [Masaki et al., J. Acoust. Soc. Jpn. E 20, 375-379 (1999)] to measure the temporal changes in the vocal tract area function during a short utterance /aiueo/ in Japanese. A time series of head-neck volumes was obtained after 640 repetitions of the utterance produced by a male speaker, from which area functions were extracted frame-by-frame. A region-based analysis showed that the volumes of the front and back cavities tend to change reciprocally and that the areas near the larynx and posterior edge of the hard palate were almost constant throughout the utterance. The lower four formants were calculated from all the area functions and compared with those of natural speech sounds. The mean absolute percent error between calculated and measured formants among all the frames was 4.5%. The comparison of vocal tract shapes for the five vowels with those from the static MRI method suggested a problem of MRI observation of the vocal tract: data from static MRI tend to result in a deviation from natural vocal tract geometry because of the gravity effect.     

Soft-landing isolation of vanadium-benzene sandwich clusters on a room-temperature substrate using n-alkanethiolate self-assembled monolayer matrixes

Gas-phase synthesized vanadium-benzene 1:2 (VBz(2)) sandwich clusters were size-selectively deposited onto bare gold and long-chain n-alkanethiolate [-S-(CH(2))(n-1)-CH(3); n = 16, 18, and 22] self-assembled monolayer (SAM)-coated gold substrates under ultrahigh vacuum (UHV) conditions. Investigation of the resulting deposited clusters was performed by infrared reflection absorption spectroscopy (IRAS) and thermal desorption spectroscopy (TDS). The IR frequencies of the soft-landed VBz(2) clusters show excellent agreement with the fundamentals reported in IR data of VBz(2) in an argon matrix. The analysis of IRAS spectra reveals that while there was no orientational preference of the VBz(2) clusters on a bare gold substrate, the VBz(2) clusters deposited onto the SAM substrates were highly oriented with the molecular axis 70-80 degrees tilted off the surface normal. In addition, analysis of TDS spectra revealed unusually large adsorption heats of the physisorbed VBz(2) clusters. The present results are explained by cluster penetration into the long-chain alkanethiolate SAM and for the first time demonstrate the matrix isolation of gas-phase organometallic clusters around room temperature.     

Broadband GHz frequency characterizations of Permalloy nanorods’ array

The radio frequency characteristics of Permalloy nanorods’ array have been examined by coplanar waveguide (CPW) cell. The Permalloy nanorods’ array was grown in anodic aluminum oxide porous templates with a diameter of 20 nm. As the Permalloy nanorods’ array was placed on CPW, the characteristic impedances of the CPW were changed from 50 to at 1 GHz. The magnitude of inductance was decreased from 3 GHz and the capacitance was increased up to twice in comparison with that of CPW. The signal attenuations were abruptly increased over 1 GHz. The propagation wavelengths due to the insertion of Permalloy nanorods’ array were decreased about 30% at 1 GHz in comparison with that of CPW without magnetic materials.     

Fluorescent detection for cyclic and acyclic alcohol guests by naphthalene-appended amino-beta-cyclodextrins

Spectroscopic and thermodynamic investigations on complexation of naphthalene-appended amino-beta-cyclodextrins 1 and 2 with cyclic alcohols (cyclohexanol and cycloheptanol) and acyclic alcohols (1-pentanol, 2-pentanol, 1-hexanol, and 1-heptanol) have been carried out. Host 1 exhibits a drastic fluorescent enhanced-signal change in the presence of alcohol guests in aqueous solution. [structure: see text]