Finite-Difference Time-Domain Analysis of the Interaction of Gaussian Evanescent Light with a Single Dielectric Sphere or Ordered Dielectric Spheres

The interaction of gaussian evanescent light with a single dielectric sphere or ordered dielectric spheres in an attenuated total reflection (ATR) geometry was analyzed by the finite-difference time-domain method. Various aspects of this interaction were investigated in terms of spatial visualizations of light intensity, reflectance vs. wavelength characteristics, the transient behavior of reflectances, and so forth. In the case of a single sphere, it was evident that the whispering gallery mode can be excited in ATR geometries, but such excitation cannot be easily confirmed only through the observation of wavelength-scanned ATR spectra. In the case of a closely packed two-dimensional array of dielectric spheres, it was found that an easy axis and also a difficult axis for light propagation exist.This paper was originally presented at the 5th International Conference on NEAR FIELD OPTICS and RELATED TECHNOLOGIES (NFO-5), which was held on December 6–10, 1998 at Coganoi Bay Hotel, Shirahama, Japan, in cooperation with the Japan Society of Applied Phisics and Mombusho Grantin Aid for Scientific Research on Priority Areas “Near-field Nano-optics” Project, sponsored by Japan Society for the Promotion of Science.     

Molecular orientation and mechanical anisotropy of polypropylene sheet containing N,N′‐dicyclohexyl‐2,6‐naphthalenedicarboxamide

Effect of mixing and processing conditions at T‐die extrusion on the structure and mechanical properties is studied for isotactic polypropylene (PP) containing a small amount of β‐form nucleating agent, N,N′‐dicyclohexyl‐2,6‐naphthalenedicarboxamide. It is found that trigonal β crystals are predominantly formed in the extruded samples containing the nucleating agent irrespective of the mixing and processing conditions, leading to the marked mechanical toughness. On the contrary, the molecular orientation is significantly affected by the mixing and processing conditions. In particular, it should be noted that PP molecules in the extruded sheet which was mixed at high temperature (260 °C) and extruded at low temperature (200 °C) orient perpendicular to the applied flow direction. As a result, the sheet shows anomalous mechanical anisotropy. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 424–433, 2009     

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).     

Engineered synapse model cell: genetic construction and chemical evaluation for reproducible high-throughput analysis

Bioassay models of neural functions must lend themselves to high-throughput analysis in neural drug discovery. However, smart analysis methods for these functions have not yet been fully established. Here, we describe the development of a synapse model for cell-based biosensing. The engineered synapse model cell expresses ionotropic glutamate receptor on its surface, like the neural postsynaptic membrane. The advantages of the model cell are the ease of handling and reproducibility as compared with the cultured neural cell, and it can be employed to evaluate receptor function through ion flux analysis. The agonist-induced sodium influx was monitored as an agonist concentration-dependent increase in the observed fluorescence signal. Furthermore, we found that our model cell enables the correction of uneven cellular signal levels using a reporter system. Our engineered synapse model cell can be employed as a powerful tool for the screening of lead substances in pharmaceutical high-throughput analysis.     

Infrared Problem for the Nelson Model on Static Space-Times

We consider the Nelson model on some static space-times and investigate the problem of existence of a ground state. Nelson models with variable coefficients arise when one replaces in the usual Nelson model the flat Minkowski metric by a static metric, allowing also the boson mass to depend on position. We investigate the existence of a ground state of the Hamiltonian in the presence of the infrared problem, i.e. assuming that the boson mass m(x) tends to 0 at spatial infinity. We show that if m(x) ≥ C |x|⁻¹ at infinity for some C > 0 then the Nelson Hamiltonian has a ground state.     

The optical characteristics of planar bilayered metallic prisms

A planar bilayered silver prisms with rounded corner is shown to have a singular optical mode depends of gaps by numerical simulation. Such behavior results from the plasmon resonance in the pairs of nanoprisms both the electric and the magnetic components of light.     

Lax表示的变形与Hamilton方程族的Lax表示

本文首先给出了构造演化方程族的Ｌａｘ表示的马文秀方法的一种变形，后对这一方法作了改进，使之适用于Ｈａｍｉｌｔｏｎ形式的方程族．作为应用，得到了具有非等谱Ｌａｘ表示的杨方程族．     

On embedding problems with restricted ramifications

Archiv der Mathematik - Let L / k be a Galois extension with Galois group G, and $(\varepsilon ): 1\to A\to E\to G\to 1$ a central extension. We study the existence of the Galois extension M / L /...     

Multiatomic step formation on GaAs(001) vicinal surfaces during thermal treatment

We observed the surface morphology of vicinal GaAs(001) after thermal treatment in AsH₃/H₂ atmosphere by atomic force microscopy (AFM). Clear multiatomic steps were formed under the high temperature thermal treatment. Next, we investigated the mechanism of step bunching during thermal treatment by two experiments from the view point of Ga atom evaporation. One is the selective thermal treatment using a partially masked GaAs wafer, and the evaporation amount of Ga atoms was estimated by AFM. The other is the investigation of photoluminescence (PL) peak energy shifts for AlGaAs/GaAs single quantum wells with a thermal treatment process at the top of the GaAs quantum well layer, compared to those without thermal treatment. These results indicate that the evaporation hardly occurs during the thermal treatment process. Therefore, step bunching phenomena on GaAs(001) vicinal surfaces during thermal treatment are probably caused by migration of the atoms detached from upside steps and their re-incorporation to downside steps.     

ON DEFINABILITY OF NORMAL SUBGROUPS OF A SUPERSTABLE GROUP

In this note we treat maximal and minimal normal subgroups of a superstable group and prove that these groups are definable under certain conditions. Main tool is a superstable version of Zil'ber's indecomposability theorem. MSC: 03C60.