Charge density study under high pressure

The experimental and analytical method of the high-pressure powder experiment at BL10XU, SPring-8, is described. There is no doubt that BL10XU must be one of the most appropriate beam lines for high pressure X-ray diffraction experiment taking advantage of third generation synchrotron source. As an example of the advanced charge density study under high pressure, the structural change of Cs₂Au₂Br₆ by applying pressure is studied by Rietveld/MEM analysis. It reveals that the structural change of Cs₂Au₂Br₆ by applying pressure occurs basically at electron level, such as valence state change and chemical bonding, which may be called the electronic phase transition.     

Selection of meaningless steady noise for masking of speech

This paper focuses on masking speech with meaningless steady noise as a way of realizing a comfortable sound environment. As a basis for research, meaningless steady noise at minimum sound pressure levels for masking of male or female meaningful speech is considered, based on psychological experiments using a method of adjustment. From the results, band-limited pink noise can be selected as the most effective noise for masking of speech. In the case of speech with a lower sound pressure level, the sound pressure level of the meaningless steady noise needs to be a little higher.     

Evaluation of the molecular recognition of peptide-conjugated polymer.

We have recently reported on dodecamer peptides (HPPMDFHKAMTR, CHPQPLKSRNPL) which recognize 52-58th and 197-203rd amino acid sequences of glucose oxidase (GOx) by screening via a phage random peptide library. In this study, a side-chain protected peptide monomer (PPM) was synthesized using two peptides (HPPMDFHKAMTR, SHPQPLKSRNPL) and acryloyl chloride. The peptide-conjugated polymer (PCP) was copolymerized with PPMs and N,N-diethylacrylamide (DEAA). The affinity of PCPs to GOx was estimated using surface plasmon resonance detection. This study suggests that PCP is a valuable molecular recognition biomolecule.     

WIDE RANGE DETECTOR USING PARABOLIC CYLINDRICAL MIRROR FOR THz APPLICATIONS

A new, wide-band, high-speed and high-sensitivity THz detector has been developed. The prototype detector consists of a parabolic cylindrical mirror, a long wire antenna and a Schottky barrier diode. Direct detection measurements have shown a stable sensitivity of 150 ± 50 V/W for 1–2 THz without any adjustments. The long wire antenna was fixed at the focus of parabolic cylindrical mirror then it has been realized less operation steps, easy coupling to the external THz signals and a dramatic enhancement in the practicality of this system. The optically polished mirror and frosted surface one showed comparable sensitivities, thus easy polishing and less cost mirror fabrication can be applied for this system. The radiation pattern showed a maximum radiation angle of approximately 23° with its dominant main lobe, which was attributed to the wire antenna character and confirmed good agreements with classical antenna theory.     

Simple and rapid determination of hydrogen peroxide using phosphine-based fluorescent reagents with sodium tungstate dihydrate.

A simple batch method for the fluorometric determination of hydrogen peroxide using phosphine-based fluorescent reagents has been developed. A rapid, mild and selective derivatization reaction was achieved by adding sodium tungstate dihydrate to the reaction mixture of hydrogen peroxide and a phosphine-based fluorescent reagent. When 4-diphenylphosphino-7-methylthio-2,1,3-benzoxadiazole was used as a reagent, the derivatization reaction was completed after 2 min at room temperature. The calibration curve was linear between 12.5 and 500 ng hydrogen peroxide in a 10 microL sample solution. This method is accurate and has potential for on-line applications.     

Preparation and certification of the new reference materials; plastics (disk form, JSAC 0621-0625) for determination of mercury using x-ray fluorescent analysis.

The Japan Society for Analytical Chemistry has developed some new plastic certified reference materials (CRMs) for the analysis of mercury in polyester disks using XRF analysis. These CRMs (named as JSAC 0621-0625) were prepared by casting polyesters including a toluene solution of organometallic compounds as a standard. Concentrations of the five levels of mercury ranged from 0 to 250 mg/kg. Homogeneity tests of prepared disks had shown excellent results. Interlaboratory comparison study for the certification was performed by 15 laboratory participants. The z-scores in robust statistical method was applied for the evaluation of outliers. The certified values were assigned after discarding outliers. The uncertainties of certified values were determined as the confidence levels of 95%.     

Photodimerization of benzene -photochromism of layered dithiacyclophane-

A novel cage compound was obtained by irradiation of a quadruple-layered dithiacyclophane and showed thermally reverse reaction.     

Synthesis of pyrimidinopurinophanes

Synthesis and structures of the title compounds 2a–d are described. In spite of non-parallel orientation of the two base rings, fairly large hypochromism was observed for 2a–d.