First direct visualization of spillover species emitted from pt nanoparticles

We studied the methanol adsorption behavior of Pt nanoparticles that were vacuum-deposited on a TiO(2)(110) surface at room temperature by using an ultrahigh vacuum (UHV) scanning tunneling microscope (STM). A large number of bright spots were observed on fivefold-coordinated Ti (Ti(5c)) rows of the TiO(2)(110) surface after exposure of the Pt/TiO(2)(110) to methanol vapor. We assigned the bright spots to methoxy species. These were mobile and were found to hop along the Ti(5c) rows. In situ time-resolved STM observations of the formation and migration of the bright spots on the Pt/TiO(2)(110) were carried out in the presence of methanol. The bright spots were produced at the periphery of the Pt nanoparticles and migrated to the substrate Ti(5c) rows. We discuss the spillover process and behavior of the methoxy species on the Pt/TiO(2)(110).     

Establishment of absolute stereostructure of falcarindiol, algicidal principle against Heterocapsa circularisquama from Notopterygii Rhizoma

Falcarindiol (1) was isolated as an algicidal principle against the harmful red tide dinoflagellate, Heterocapsa circularisquama, from Notopterygii Rhizoma through bioassay-guided separation. In order to determine the ambiguous absolute structure of this active principle, all three stereoisomers as well as falcarindiol (1) were synthesized. As a result of intensive analysis of their physicochemical properties, the configuration of 1 was revealed to be 3R,8S. On the other hand, (3S,8S)- and (3S,8R)-isomers were found to exhibit more potent algicidal activity than (3R,8S)-falcarindiol (1) isolated from Notopterygii Rhizoma. In addition, the diyne moiety of 1 was established as the crucial structural requirement for algicidal potency.     

Metal Ionically-controlled Optical Signaling Based on a Chromoionophore-derived Calix[4]crown

A chromoionophore-derived calix[4]crown, 1 , possessing an effective signal-controllable function by metal ionic inputs has been newly synthesized, whose function is mainly of our interest, by transforming the process of receptor activation to one that may be detected by an optical signal (i.e. color change), the basic feature of antagonist-agonist competition may be reproduced readily and visually detected. The process would be particularly new within the field of optical read-out receptors. Further, from the standpoint of material sciences, the controllable signal function may not only be welcome for molecular information processing, but also contribute to the design of new sensory materials.     

Precise synthesis of a series of poly(4‐n‐alkylstyrene)s and their glass transition temperatures

Poly(4‐n‐alkylstyrene)s with six kinds of n‐alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, and octyl groups covering wide molecular weight range from around 5 k to over 100 k were precisely synthesized by living anionic polymerizations. It was confirmed that all the polymers obtained have narrow molecular weight distribution, that is, M_w/M_n is all less than 1.1, by SEC. T_gs of all the polymers were estimated by DSC measurements and it turned out to be clear that their molecular weight dependence was well described by the Fox–Flory equations. Furthermore, it is evident that T_g monotonically decreases as a number of carbon atoms of n‐alkyl group is increased, though T_g values are all 20 K or more higher than those reported previously for the same polymer series. This is because backbone mobility increases by introducing longer n‐alkyl side groups with high mobility, while T_g difference in between this work and the previous one may due to the experimental conditions and also to the molecular weight range adopted. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 757–763     

Alkyl side chain length dependent compatibility of poly(4‐n‐alkylstyrene)s and 1,4‐rich polyisoprene blends

We investigated the compatibility of blends of 1,4‐rich polyisoprene (1,4‐PI) and poly(4‐n‐alkylstyrene)s with six kinds of n‐alkyl side groups, that is, methyl, ethyl, propyl, butyl, hexyl, and octyl focusing on carbon number of alkyl groups. Poly(4‐methylstyrene)/1,4‐PI blend was turned out to be immiscible at all temperature range adopted in this work and poly(4‐ethylstyrene)/1,4‐PI blend revealed UCST type phase behavior, while the others were found to be compatible. The phase diagrams of poly(4‐ethylstyrene)/1,4‐PI blends were obtained by optical microscopy, and the temperature dependence of the Flory‐Huggins interaction parameter χ has been estimated to be χ = ?0.036 + 24/T by applying lattice theory, where T is the absolute temperature. From this relationship χ value at room temperature (298 K) was calculated to be 0.045, the value is reasonably low for miscible polymers system. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55 , 1791–1797     

Triggered single-photon emission and cross-correlation properties in InAlAs quantum dot

Triggered single-photon generation from InAlAs quantum dot (QD) was demonstrated for the first time. Emitted photon energy coincides with high detection efficiency range of Si single-photon detectors, which is highly suitable for free-space communication. Single-QD spectroscopy and crossed photon correlation measurements unambiguously revealed that several emitting lines observed in a single mesa structure originated from the identical QD, and two temporary competing decay processes associated with neutral states and charged states were identified. Presence of the competing process is also inferred from an analysis of steady-state photoluminescence intensities. Formation process of charged exciton in QD is also discussed.     

Assessment of fluoroalkyltin compounds as fluorous Lewis acid catalysts

The synthesis of a variety of organotin compounds with 1H, 1H, 2H, 2H‐perfluorooctyl groups is reported, together with an improved method for the corresponding distannoxane. Unique properties of this compound are disclosed in terms of fluorophilicity and activity as a Lewis acid catalyst in comparison with other mono‐nuclear derivatives. A new criterion for obtaining high solubility in fluorocarbon solvents is presented. Copyright © 2003 John Wiley & Sons, Ltd.     

A non‐linear k–ε model with realizability for prediction of flows around bluff bodies

The incompressible flow around bluff bodies (a square cylinder and a cube) is investigated numerically using turbulence models. A non‐linear k–ε model, which can take into account the anisotropy of turbulence with less CPU time and computer memory then RSM or LES, is adopted as a turbulence model. In tuning of the model coefficients of the non‐linear terms are adjusted through the examination of previous experimental studies in simple shear flows. For the tuning of the coefficient in the eddy viscosity (=C_μ), the realizability constraints are derived in three types of basic 2D flow patterns, namely, a simple shear flow, flow around a saddle and a focal point. C_μ is then determined as a function of the strain and rotation parameters to satisfy the realizability. The turbulence model is first applied to a 2D flow around a square cylinder and the model performance for unsteady flows is examined focussing on the period and the amplitude of the flow oscillation induced by Karman vortex shedding. The applicability of the model to 3D flows is examined through the computation of the flow around a surface‐mounted cubic obstacle. The numerical results show that the present model performs satisfactorily to reproduce complex turbulent flows around bluff bodies. Copyright © 2003 John Wiley & Sons, Ltd.