Hiding an image with a light-scattering medium and use of a contrast-discrimination method for readout

Hiding image data with a material such as a light-scattering medium is useful as an initial stage of data protection, because the hidden image can be detected only by observation with a specific technique. A light-scattering medium is used to hide the image data, and a low-temporal-coherence interferometer performs the readout processing. A new readout method for detecting pixel values of the image is proposed to overcome spatial variation of the light intensity and distortion of the interference fringes. The introduction of spatial coding further improves the performance by overcoming spatial variations of the light-scattering medium and variations in the reflectance of given pixels.     

Polymer film-type channel electron multipliers: Their characteristics and comparison with bulk-type flexible multipliers

Polymer film-type channel electron multipliers (CEMs) were developed and their characteristics investigated in comparison with bulk-type flexible CEM. As film-type CEMs, a paint-coating-type CEM and a solvent-etching-type CEM were fabricated. The paint-coating-type CEM is made by coating a “paint” which is prepared by dissolving in a solvent an electronically conductive polymeric composition having a high secondary electron emission yield. Up to the present study the mean gain of the film-type CEM, in spite of the lower resistivity of the dynode, seems to be slightly more dependent on the count rate than that of the bulk-type CEM made of the same material. However, the convenience of fabricating the dynode film by coating the dynode-forming paint on the internal surface of any shaped tube or a flexible polymer tube would overcome the slight disadvantage mentioned above.     

Temperature dependency of radiation damage in inorganic materials by 300 keV electrons

Temperature dependency of radiation damage in albite and natrolite was studied quantitatively by measuring the diffraction intensity with imaging plates. Radiation damage was reduced at low temperature in albite but was enhanced in natrolite. A damage process model, in which creation and annihilation of localized defects were considered, was proposed. According to this model, Boltzmann factor in temperature dependency is dominated by a difference between energy for diffusion of the localized defects and energy for breakdown of a crystal framework. When the diffusion energy is larger than breakdown energy, the activation energy in Boltzmann factor seems to be effectively negative.     

Tailoring the Optical Properties of Epitaxially Grown Biaxial ZnO/Ge,and Coaxial ZnO/Ge/ZnO and Ge/ZnO/Ge Heterostructures

Heterostructures of epitaxially grown biaxial ZnO/Ge, and coaxial ZnO/Ge/ZnO and Ge/ZnO/Ge heterostructured nanowires with ideal epitaxial interfaces between the semiconductor ZnO sublayer and the Ge sublayer have been fabricated via a two‐stage chemical vapor–solid process. Structural characterization by high‐resolution transmission electron microscopy and electron diffraction indicates that both the ZnO and Ge sublayers in the heterostructures are single crystalline. A good epitaxial relationship of (100)_ZnO∥(2 0)_Ge exists at the interface between ZnO and Ge in the ZnO/Ge biaxial heterostructure. There is also an epitaxial relationship of (0 0)_ZnO∥(020)_Ge at the interface between the ZnO and Ge substructures in the coaxial ZnO/Ge/ZnO heterostructures, and a good epitaxial relationship of (0 0)_ZnO∥(0 0)_Ge at the interface between ZnO and Ge in the Ge/ZnO/Ge coaxial heterostructure. Structural models for the crystallographic relationship between the wurtzite‐ZnO and diamond‐like cubic‐Ge subcomponents in the heterostructures are given. The optical properties for the synthesized heterostructures are studied by spatially resolved cathodoluminescence spectra at low temperature (20 K). Excitingly, the unique biaxial and coaxial heterostructures display unique new luminescence properties. It is concluded that the ideal epitaxial interface between ZnO and Ge in the prepared heterostructures induces new optical properties. The group II–VI Ge‐based nanometer‐scale heterostructures and their interesting optical properties may inspire great interest in exploring related epitaxial heterostructures and their potential applications in lasers, gas sensors, solar energy conversion, and nanodevices in the future.     

采用TAB快速测定EMD性能

TAB(聚四氟乙烯乙炔黑)是好的导电和粘结合二为一的材料,采用该材料能快速评定EMD的性能。     

High performance liquid chromatographic separation of diacylglycerol acetates to quantitate disaturated species of lung phosphatidylcholine

A high-performance liquid chromatographic (HPLC) separation of diacylglycerol acetates to quantitatite disaturated species of lung phosphatidylcholine (PC) was studied. The diacylglycerol acetates were applied on a reversed phase column, eluted by an isocratic solvent, acetonitrile/isopropanol/water (35:15:1, v/v/v) at a flow rate of 1 ml/min, and detected by differential refractometry (RI). This isocratic HPLC method was useful to separate disaturated species from the others of lung PC. The quantitative analysis of the molecular species separated by HPLC was studied by RI detection. Chroamtograms obtained by RI detection and radioactivity determination of diacylglycerol [³H]acetates prepared by [³H]acetic anhydride were almost identical. The RI detector responsed in the same degree for different, authentic standards of diacylglycerol acetates. The detection limit with RI detection was about 30 nmoles. Molecular species of PCs from human lung and carcinoma tissues were analyzed by this HPLC method. The contents of disaturated species were very similar to those reported previously. These results indicate that RI detection is very useful in the nmole range for the quantitative analysis among the molecular species containing disaturated species.     

Biomimetic ion-channel sensors based on host-guest molecular recognition in Langmuir-Blodgett membrane assemblies

Biomimetic “ion-channel sensors” based on host-guest molecular recognition were constructed by incorporating several kinds of receptor molecules in Langmuir-Blodgett (LB) molecular assemblies deposited directly on glassy carbon electrodes. The receptors used were valinomycin, bis(crown ether)s, macrocyclic polyamine and cyclodextrin polyamine. The binding of charged stimulants (metal ions, inorganic and organic anions) to these receptors induced a marked increase (or decrease) in the ion permeability of the membranes, as detected by cyclic voltammetry using [Fe(CN)₆]^4- or [Ru(bpy)₃]²⁺ as marker ion. Such a mode of response, corresponding to model “channel opening (or closing)”, can be explained on the basis of the charge-charge interaction involving the stimulant, marker ion and lipid.     

Portable sick house syndrome gas monitoring system based on novel colorimetric reagents for the highly selective and sensitive detection of formaldehyde

Formaldehyde (HCHO) emitted from the furniture and the walls in the rooms injures the eyes, nose, and respiratory organs and causes allergies, which is called sick house syndrome. We designed and synthesized novel colorimetric HCHO-sensing molecules (KD-XA01 and KD-XA02) which possess an enaminone structure and developed a hand-held instrument to monitor indoor HCHO gas with the use of KD-XA01. These sensing molecules produced speedy color changes from colorless to yellow under mild conditions, which was caused by the fact that the enaminone structure in the reagent reacts with HCHO to give a lutidine derivative. This reaction took place not only in the solution phase but also in the solid phase (surface of the cellulose paper). To take advantage of this phenomena, a handy and rapid monitoring system has been developed for detecting indoor HCHO gas using a highly sensitive and selective detection tablet constructed from the porous cellulose paper that contains silica gel as an adsorbent, KD-XA01, and phosphoric acid under optimum conditions. This instrument detected the surface color change of the tablet from white to yellow, which was monitored as a function of the intensity of the reflected light illuminated by an LED (475 nm). The response was proportional to the HCHO concentration at a constant sampling time and flow rate; 0.05 ppm HCHO, which is under the standard value set by the World Health Organization, was able to be detected in 5 min. The detection limit was 0.005 ppm. This monitoring system was not interfered by carbonyl compounds such as acetaldehyde and acetone, alcohols, hydrocarbons, and typical gases such as carbon monoxide, carbon dioxide, nitrogen dioxide, etc., which contributes to the measurement of correct HCHO concentrations. It was possible to monitor the HCHO gas in the room of a new apartment and school using this instrument; the response values were in good agreement with those obtained by the standard DNPH method. This highly sensitive, selective, and handy HCHO gas monitor is widely applicable and convenient for users who are not specialists in this field.