Dynamical properties of ethylene glycol and glucose studied by temperature-modulated differential scanning calorimetry and Brillouin scattering

The fragility of ethylene glycol and glucose aqueous solution systems has been investigated by temperature-modulated differential scanning calorimetry (TMDSC). The frequency and temperature dependences of complex specific heat have been observed in the vicinity of a glass-transition temperature T _g . It is shown that the value of the fragility index m can be determined from the temperature dependence of the α-relaxation times observed by TMDSC. We have also studied the elastic properties of these aqueous solutions by micro-Brillouin scattering, and determined these relaxation times of elastic properties in the gigahertz range.     

Electrochemical properties of Li symmetric solid-state cell with NASICON-type solid electrolyte and electrodes

All-solid-state phosphate symmetric cells using Li₃V₂(PO₄)₃ for both the positive and negative electrodes with the phosphate Li_1.5Al_0.5Ge_1.5(PO₄)₃ as the solid electrolyte were proposed. Amorphous Li_1.5Al_0.5Ge_1.5(PO₄)₃ was added into the electrode to increase the interface area between the active materials and the electrolyte. Any other phases were not formed at the electrode/electrolyte interface even after hot pressing at 600 °C. The discharge capacity was 92 mAh g^? 1 at 22 µA cm^? 2 at 80 °C, and 38 mAh g^? 1 at 25 °C, respectively. Symmetric cell configuration leads to simplify the fabrication process for all-solid-state batteries and will reduce manufacturing costs.     

A new biisoflavonoid from the roots of Erythrina variegata

A new biisoflavonoid, biseryvarin A (1a), together with two known compounds were isolated from the roots of Erythrina variegata. The structure of biseryvarin A was established on the basis of spectroscopic evidence. Biseryvarin A is the first dimeric isoflavonoid possessing isoprenoid groups from the genus Erythrina. Biseryvarin A showed low activity against methicillin-resistant Staphylococcus aureus (MRSA).     

Dynamic Vapochromic Behaviors of Organic Crystals Based on the Open–Close Motions of S‐Shaped Donor–Acceptor Folding Units

The first vapochromic organic crystals are described with respect to their preparation, color change, adsorption/desorption properties, crystal structures, and color‐change mechanism. Non‐solvatochromic, 1,4,5,8‐naphthalene‐tetracarboxylic diimide (NDI) derivatives 1 a bearing two pyrrole imine (PI) tethers have been used as a motif for the crystal packing template. Red‐purple vapochromic solid 3 was prepared by evacuation of orange crystals 2 (equivalent to 1 a ?2 MeOH), obtained by recrystallization of 1 a from MeOH. Solid 3 showed high‐adsorption ability and unprecedented vapor‐dependent color changes upon exposure to a variety of organic vapors, whereas light brown amorphous solid 1 a , did not show vapo‐ or solvatochromic behavior toward any organic solvent. The strong adsorption capability of 3 was confirmed by TGA experiments and adsorption/desorption isotherms. Analysis of the solid‐state UV/Vis analysis revealed that the vapor‐dependent color changes of 3 were owed to the specific interference of solvent vapors with its broad CT absorbance at λ=450–650 nm. Packing structures of 1 a in orange crystals 2 , red‐purple solid 3 , and regenerated orange solid 2 were unequivocally established by single crystal and synchrotron powder X‐ray diffraction, respectively. Molecular structures and arrays of 1 a in these materials indicated that 1) unit 1 a had an S‐shaped folded conformation in 2 and 3 by intramolecular donor–acceptor interactions between NDI and two PI units; 2) inclusion of the guest vapor into the S‐shaped template decreased the intramolecular PI‐NDI interactions, accompanied by increasing intermolecular NDI‐NDI and PI‐PI interactions; and 3) such flexible, open–close motions of the S‐shaped template could be repeated during reversible adsorption/desorption processes without degradation of crystal packing. The adsorption properties and mechanism of molecular shape‐dependent vapochromic behavior of 3 are discussed with reference to experimental results, crystallographic data, and theoretical calculations.     

Fast image enlargement using predefined codebook and eigenspace backprojection for lost pixel

In this paper, a new image enlargement method applying the backprojection for lost pixel (BPLP) to the predefined codebook-based method is proposed. BPLP is a method for image restoration. In BPLP, the eigenspace reflecting the characteristics of an input image is generated from the remained pixels and is used to restore the missing pixels. In the proposed method, the eigenspace is replaced by one generated from the predefined codebook (PDC). PDC represents edge-blurring properties in a small image patch and consists of pairs of low- and high-frequency image patches on various edge patterns. By replacing the PDC-based estimation of lost high-frequency components with BPLP, a fast image enlargement method retaining its performance can be developed. Through some experiments, the effectiveness of the proposed method was demonstrated. Especially, it was confirmed that the processing time of the proposed method was shortened to about 1/50 that of the PDC-based method.     

Polarity determination of wurtzite-type crystals using hard x-ray photoelectron diffraction

The surface structure of a single-crystal ZnO wafer was studied by angle-resolved x-ray photoelectron spectroscopy (ARXPS) using synchrotron radiation. As a result, well-defined x-ray photoelectron diffraction (XPD) patterns were obtained for the (0001) and (000$\overline{1}$) polar surfaces using the photoemission from the Zn 2p_3/2 and O 1s core levels. The XPD patterns were indexed assuming forward scattering of photoelectrons by neighboring ions. Further, the XPD patterns for the (0001) and (000$\overline{1}$) surfaces were different from each other, indicating the possibility for using the XPD technique for polarity determination.     

An efficient optical resolution of nitrogen-centered chiral β-hydroxy-tetraalkylammonium salts via complexation with (R)-BINOL

The optical resolution of nitrogen-centered chiral β-hydroxy-tetraalkylammonium bromides is demonstrated by using chiral BINOL as a complexing agent. Determination of the enantiopurities and absolute configurations of the resolved N-chiral tetraalkylammonium salts are described.     

A basic study on the sound field analysis of periodic structures by boundary integral equation method

This study deals with the development of the approximate method to analyze the sound field around equally spaced finite obstacles, using the periodic boundary condition. First, on the assumption that the equally spaced finite obstacles are the periodically arranged obstacles, the sound field is analyzed by boundary integral equation method with a Green’s function which satisfies the periodic boundary condition. Furthermore, by comparing these results and the exact solution by using the fundamental solution as Green’s function, the validity of the approximate method is also investigated. Next, in order to evaluate the applicability of the approximate method, the simple formula using some parameters, i.e., the frequency, the period, and the number of obstacles, etc., is proposed. The results of the sound field analysis applied the formula are presented.     

Optimization of mark edge recording waveform for a phase change rewritable optical disk using a 680 nm laser diode

A high density mark edge recording method on a phase change rewritable disk is reported. A carrier-to-noise ratio of 55 dB for a mark length of 0.55,μm is obtained by using a 680 nm, NA 0.6 head and a phase change rewritable disk. In mark edge recording, it is necessary to record each mark in correct length. A new laser power modulation pattern is proposed. This pattern consists of a first-pulse, a multi-pulse chain and a last-pulse. Both positions of the first-ptilse and the last-pulse are movable. By adjusting these positions, a jitter, σ/T_w (T_w is window margin), is improved to 6.5% in high density EFM (Eight to Fourteen Modulation) recording of 0.4 μm/bit.