Heat-generating property of a local plasmon resonator under illumination

We have investigated the heat generation from gold nanoparticles resulting from their local plasma resonance. We have demonstrated the self-assembly of Au nanoparticle arrays/dielectric layer/Ag mirror sandwiches, i.e., a local plasmon resonator, using a dynamic oblique deposition technique. The thicknesses of the Au and dielectric layers were changed combinatorially on a single substrate. As a result, local plasmon resonator chips were successfully fabricated. Because of strong interference, their optical absorption can be controlled between 0.0% and 97% in the near-IR region, depending on the thickness of the dielectric layer. We evaluated the heat generation from Au nanoparticles by measuring the temperature of water with which a cell prepared on a chip is filled under laser illumination. The change in the water temperature is proportional to the optical absorption of the local plasmon resonator chips. This suggests that the photothermal conversion efficiency can be controlled by interference. These features make the application of the local plasmon resonator to nanoheaters, which can spatiotemporally control heat generation, suitable.     

Electron beam epitaxy of alloy semiconductors

Abstract

It was investigated that, when an Al evaporated layer on a GaP (GaAs, GaAs_1?y P _y ) substrate was bombarded with total fluences of 0.1?1.0 × 10¹⁸ electrons cm^?2 at 7 MeV and at 50°C, a thin heteroepitaxial layer of Al _x Ga_1?x P (Al _x Ga_1?x As, Al _x Ga_1?x As_1?y P _y ) crystal was grown on S-doped (111), (100) and (110) GaP [(110) Cr, O-doped GaAs, (100) Te-doped GaAS_1?y P _y ] substrates.

Evidence for the creation of the epilayers before annealing was obtained from measurements using an X-ray diffractometer, an X-ray photoelectron spectrometer, a reflection high-energy electron diffractometer, a transmission electron microscope and a scanning transmission electron microscope. In the case of Al/GaP, the epitaxial layers of Al_～0.25Ga_～0.75P, Al_～0.5Ga_～0.5P and Al_～0.75Ga_～0.25P were grown on (111), (100) and (110) GaP substrates, respectively. Their compositions did not vary with the total electron fluence.     

Influence of radial electric field on trajectories of plug potential bounce ion in the tandem mirror

Bouncing ions between the plug potentials play an important role in improvement of the axial confinement in the tandem mirror. We examined the influence of the radial electric field on the trajectories of the ions passed through the anchor cell with nonaxisymmetric magnetic configuration on the assumption that the shape of the magnetic flux tube was shifted from the shape of the equipotential surface of the plasma at the mirror throats of the anchor cells. The discrepancy between the shapes enhanced the radial drift of the bounce ion. Radial potential profile of the core plasma was controlled by adjustment of the radially separated endplate potentials, and it was found that the flattened radial potential profile was effective for the decrease of the radial drift. Presented at 5th Workshop “Role of Electric Fields in Plasma Confinement and Exhaust”, Montreux, Switzerland, June 23–24, 2002.     

Ultrasonic butt welding of aluminum,aluminum alloy and stainless steel plate specimens

Welding characteristics of aluminum, aluminum alloy and stainless steel plate specimens of 6.0 mm thickness by a 15 kHz ultrasonic butt welding system were studied. There are no detailed welding condition data of these specimens although the joining of these materials are required due to anticorrosive and high strength characteristics for not only large specimens but small electronic parts especially. These specimens of 6.0 mm thickness were welded end to end using a 15 kHz ultrasonic butt welding equipment with a vibration source using eight bolt-clamped Langevin type PZT transducers and a 50 kW static induction thyristor power amplifier. The stainless steel plate specimens electrolytically polished were joined with welding strength almost equal to the material strength under rather large vibration amplitude of 25 microm (peak-to-zero value), static pressure 70 MPa and welding time of 1.0-3.0 s. The hardness of stainless steel specimen adjacent to a welding surface increased about 20% by ultrasonic vibration.     

Depolarization in reentrant spin glasses: a comparison between neutron and muon probes

In the amorphous ( Fe_1-x Mn_x)₇₅ P₁₆ B_6 Al_3 alloys, muon and neutron depolarization data, combined with the results of small angle neutron scattering, magnetization and Mössbauer spectroscopy, probe the existence of three distinct magnetic transitions at T_C, T_K and T_F (T_F < _K < _C).     

Acoustic characteristics of rough voice: Subharmonics

This study investigates the relationship between rough voice and the presence of Subharmonics, which correspond to smaller yet distinct peaks located between two consecutive harmonic peaks in the power spectrum. Spectrum analysis was undertaken in 389 pathologic voices, of which 20 had subharmonics. Although all 20 voices had roughness perceptually, 8 had normal jitter and/or shimmer. The degree of roughness had a significant inverse relationship with the frequency of subharmonics. By digital signal processing, sound samples with various types of subharmonics were synthesized and perceptually analyzed. Power and frequency of subharmonics in the synthesized sound also had significant relationships with the degree of roughness. Rough voice is acoustically characterized not only by jitter and shimmer but also by the presence of subharmonics in the power spectrum. Subharmonics are important acoustic properties for objective evaluation of rough voices.     

Spin gap systems: What can be measured by muon spin relaxation?

Muon spin relaxation (μSR) and nuclear magnetic resonance (NMR) are powerful probes of magnetism, which have been extensively applied to studies of spin gap systems. Comparison of results obtained with the two techniques gives complementary results, as each is sensitive to different aspects of spin gap magnetism. We discuss recent μSR measurements of the spin ladder compounds Sr _n?1Cu _n+1O_2n , pure and doped Haldane materials (Y_2?x Ca _x )Ba(Ni_1?y Mg _y )O₅, and doped spin Peierls compounds (Cu_1?x Zn _x )(Ge_1?y Si _y )O₃.     

Development of Non-Halogen Flame Retardant Optical Fiber and Optical Fiber Cord

A non-halogen highly flame-retardant 0.9mm optical fiber and 2.0mm simplex optical cord, which are harmonized with the ecosystem, have been developed. The characteristics of them are presented in this paper.     

Time‐resolved x‐ray fluorescence for monitoring the intake of mineral nutrients in living plants

We have applied a time‐resolved means of measurement for studying living plants. The intake of mineral nutrients in a living plant such as stevia has been observed by this measuring instrument. A solution containing K, Ca, Mn, Fe, Cu, and Zn compounds was used as the mineral nutrient solution. The concentrations of the standard solutions were specifically chosen to obtain optimal intensities of the x‐ray peaks. The time dependence of the x‐ray fluorescence (XRF) intensity showed specific intake processes depending on the type of element. In addition, the experimental results suggest differences in the translocation of each element in the stevia stem. We conclude that time‐resolved XRF is a powerful technique for studying living plants. Copyright © 2007 John Wiley & Sons, Ltd.     

微小圆管中分裂火焰的实验与理论研究

对丙烷/空气在内径2 mm的圆管内的预混燃烧进行了实验研究,借助于高速数码摄像机发现了分裂火焰现象,其中一个为向上游传播的较亮的常规火焰,另一个为向下游传播的较暗的微弱火焰。这些火焰先后熄灭,经过一段时间后又重复发生自着火、分裂、反向传播、灭火过程。这种现象在富燃、化学恰当比以及贫燃火焰中都有存在。一维非稳态计算表明化...