Photoabsorption cross section measurements of CO2 between 106.1 and 118.7 nm at 295 and 195 K

High-resolution vacuum ultraviolet carbon dioxide photoabsorption cross sections are required for modeling airglow emissions from the Martian and Venusian atmospheres and for photochemical models of those atmospheres. We report cross section measurements on CO₂ at 295 and 195 K between 106.1 and 118.7 nm at a spectral resolution of 0.005 nm. Significant deviations from the results of previous, lower-resolution measurements are apparent, particularly in regions of sharp spectral structure. Temperature dependence in the photoabsorption cross sections is evident throughout the region, being especially pronounced at wavelengths greater than 113 nm.     

Sectorial solution to semilinear singular partial differential equation

We shall show the solvability of semilinear Fuchsian partial differential systems in a multi-sectorial domain. Our equation contains a linearizing equation of a singular vector field to its linear part when so-called small denominators occur. We will show the existence of an analytic solution in a multi-sectorial domain without assuming any Diophantine condition.     

Rapidly convergent iteration method for simultaneous normal forms of commuting maps

We propose a new rapidly convergent iteration scheme under weak simultaneous arithmetic conditions for overdetermined systems related to simultaneous conjugation of commuting maps. The first application is for commuting holomorphic maps in fixing the origin, not necessarily diffeomorphisms if . The second one is for orientation preserving Gevrey circle mappings by means of nonlinear superposition estimates. Received January 7, 1998; in final form July 28, 1998     

Preparation of Cu2ZnSnS4 single crystals from Sn solutions

We investigated the phase diagrams of the Cu₂ZnSnS₄ (CZTS)–Sn pseudobinary system in order to obtain knowledge useful for the growth of high-quality CZTS single crystals using a solution-based method. For Sn solutions saturated with less than ～60 mol% CZTS, the solutes are separated into two phases (CZTS phase+SnS_x phase+liquid phase). On the other hand, for solutions with more than 60 mol% CZTS, the solutes are single phase (CZTS phase+liquid phase). The CZTS single crystals were obtained from a 70 mol% CZTS solution (liquid temperature 850 °C) at 900 °C. The powder X-ray diffraction (XRD) pattern of the CZTS single crystal shows preferred orientations of (112), (220) and (312) planes, confirming the Kesterite structure of CZTS. The Raman spectrum shows three peaks at 287, 338, 371 cm^?1, which corresponded to CZTS peaks. The composition of the CZTS single crystal along the growth direction is found to be slightly Cu-poor, Zn-rich and S-rich. Therefore, it is assumed that the Cu vacancy is the dominant p-type conduction mechanism.     

Incorporation of porphyrins into mesopores of MCM-41

To introduce porphyrins such as the alcoholic-hydroxyl-group-appended free base porphyrin derivative (HP) of 5-[4-(3-hydroxylpropyloxycabonyl)phenyl]-10,15,20-triphenylphorphine into mesopores of MCM-41, samples were treated with 0-4.0 mmol dm-3 HP toluene solutions and the materials obtained were characterized by various means. The framework structure of MCM-41 was not altered by the treatment. With increasing HP concentration, the specific surface area and pore size decreased; in contrast, the number of HP molecules in the material increased almost linearly from 0 to 0.17 groups nm-2. These facts reveal that the HP molecules are incorporated into mesopores of MCM-41. IR results indicated that the hydroxyl group of the HP molecule reacts with surface free SiOH groups of the MCM-41 by a dehydration reaction. Diffuse reflection UV-vis spectra of the HP-introduced material were almost the same as that of pure HP molecules. The Beers plot suggested that the HP molecules in the material are dispersed at an HP concentration less than 1.0 mmol dm-3, and above that concentration, aggregation or flattening of the HP molecules on the MCM-41 surface takes place.     

Wide spectral range third-order autocorrelator based on ultrafast nonresonant nonlinear refraction

We demonstrate a simple scheme for a wide spectral range, third-order autocorrelator based on ultrafast nonlinear Kerr-type refraction. The technique was successfully used to characterize high-energy ultrashort pulses at 1550 and 1300 nm, where the pulse's shape and width are two of the most critical parameters. Because of its simplicity, this technique is also a powerful tool for the optimization of high-power chirped-pulse amplified laser systems, in which slight misalignment of the stretcher-compressor gratings can lead to spatiotemporal pulse distortions. In addition, it can be extended to low-power mode-locked oscillators.     

Rapid diagnosis of drug intoxication using novel NAGINATA gas chromatography/mass spectrometry software

In Japan, not only the classical stimulant, methamphetamine, but also a wide variety of illicit drugs and designer drugs are abused by juveniles. It is, however, difficult to screen these drugs in human urine due to the poor availability of high-quality standards. Therefore, it is important to develop a screening method that does not require the use of standard compounds. Furthermore, if we can obtain approximate drug concentrations in biological fluids by the first screening procedure, the subsequent treatment of the patient and forensic diagnosis can be carried out more rapidly and exact quantitative analysis performed more efficiently. We have devised a rapid screening method for the simultaneous semi-quantitative analysis of 30 abused drugs using gas chromatography/mass spectrometry (GC/MS) with a retention time locking technique. Based on this method, an 'abused drugs database' was constructed including retention time (RT), qualifier ion/target ion (QT) percentage and calibration curve (values of slope and intercept) using the novel GC/MS software, NAGINATA. We compared the analytical results obtained by this method using the constructed database with those from conventional methods in six forensic cases. The number of confirmed drugs and concentrations obtained by the established method was comparable with that obtained by conventional methods. We found a significant improvement in the time for data analysis, and qualitative and quantitative information about each drug was obtained without using standards. Therefore, this new screening procedure using NAGINATA has potential for the rapid identification of poisoning and should be useful in clinical and forensic toxicological analyses.     

Development of tubulin-polymerization inhibitors based on the thalidomide skeleton

We synthesized a series of compounds based on the potent tubulin-polymerization inhibitor 5-hydroxy-2-(2,6-diisopropylphenyl)-1H-isoindole-1,3-dione [5HPP-33 (3)], which is structurally derived from thalidomide (1), and investigated their inhibitory effects on tubulin polymerization. Direct interaction between 5HPP-33 (3) and alpha,beta-tubulin heterodimer protein was demonstrated by means of a surface plasmon resonance study.