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131.
132.
T. Okada B.H. Agung Y. Nakata 《Applied Physics A: Materials Science & Processing》2004,79(4-6):1417-1419
We succeeded in synthesizing ZnO nanorods by nanoparticle assisted pulsed-laser deposition (PLD) without using any catalyst where nanoparticles formed by condensation of ablated particles play an important role. The nanorods have an average size of about 120 nm. Stimulated emission was observed from ZnO nanorods at 388 nm by optical pumping. The size-controlling of nanorods can be achieved by controlling the size and the density of these nanoparticles. PACS 61.46.+w; 81.07.Bc; 78.66.Hf; 78.67.Bf; 81.16.Mk. 相似文献
133.
N. Okada Y. Katsumura K. Ishigure 《Applied Physics A: Materials Science & Processing》1994,58(1):99-105
The corrosion resistance of carbon steel has been improved by the deposition from the mixture of Mo(CO)6 and Cr(CO)6 as well as from each carbonyl alone with an ArF-excimer laser (193 nm). The corrosion resistance attained by coating with the films from the mixture is higher than from Mo(CO)6 alone, while lower than from Cr(CO)6 alone. While the corrosion resistance increases with beam intensity monotonically over the range 4–25 MW cm–2 for the deposition from Cr(CO)6 alone, it tends to decrease slightly above 15 MW cm–2 for the deposition from Mo(CO)6 alone and from the mixture. SEM (Scanning Electron Microscope) photographs show that the films from each carbonyl and their mixture consist of small grains that are more densely packed at higher beam intensities. The comparison of the film thickness evaluated from sputtering time to remove the films with that from direct observation with SEM suggests that the density of the film increases with beam intensity. In the films deposited from the mixture, molybdenum is preferentially incorporated from the gas phase.
Present name: Department of Quantum Engineering and Systems Science 相似文献
134.
Y. Nakata S. Gunji T. Okada M. Maeda 《Applied Physics A: Materials Science & Processing》2004,79(4-6):1279-1282
Thin films of LiNbO3 were deposited by pulsed-laser deposition (PLD). Crystalline and transparent films were deposited on a sapphire substrate at 400 °C, in 100 mTorr of oxygen, with a fluence lower than 1.2 J/cm2. Droplet free films were deposited with low ablation laser fluence by the eclipse method, and waveguide losses were 15.9 dB/cm and 3.1 dB/cm. Subsequently, second-harmonic generation (SHG) was achieved by waveguide mode phase matching. The center wavelength of the matching spectrum was 853 nm, and the full width at half maximum (FWHM) was 19 nm. PACS 42.70.Mp; 52.38.Mf; 68.55.Jk; 77.84.Dy; 81.15.-z 相似文献
135.
A gold thin film was machined by laser ablation using a femtosecond laser with mask patterns in the shape of lines and numbers. The patterns were successfully transferred with proper focusing and laser fluence. The optimal femtosecond laser fluence to keep the line width was about 5.2 mJ/cm2 on the mask, and 99 mJ/cm2 on the film. The processing resolution was 13 μm, and the narrowest line width was about 4 μm. 相似文献
136.
A. Kotani T. Jo K. Okada T. Nakano M. Okada A. Bianconi A. Marcelli J.C. Parlebas 《Journal of magnetism and magnetic materials》1987,70(1-3):28-32
X-ray photoemission, X-ray photoabsorption and bremmstrahlung isochromat spectroscopy in Ce and La compounds are theoretically analyzed by using the single-site Anderson model incorporated with various final state interactions. Discussions are given on the physical information derived from the analysis and also on similarities and differences in spectral features between metallic and insulating systems. 相似文献
137.
Y. Kobayashi M. Katada H. Sano T. Okada K. Asai M. Iwamoto F. Ambe 《Hyperfine Interactions》1990,54(1-4):585-589
99Ru,61Ni,57Fe and119Sn Mössbauer spectroscopic studies were made on ternary intermetallic compounds containing ruthenium, RuxY3?xZ (Y=Fe, Ni; Z=Si, Sn). In the system of RuxFe3?xSi, two different hyperfine magnetic fields were observed at the99Ru nuclei (H hf[Ru]) in the range ofx≤1.0 and the magnitude of eachH hf[Ru] was found to decrease with an increase in the ruthenium concentrationx. Both the99Ru and119Sn Mössbauer spectra of Ru2FeSn could be analyzed with two sets of magnetically split lines. The61Ni Mössbauer spectra of Ru2NiSn were obtained at 5 and 77 K. 相似文献
138.
Recently, Kim and Oh expressed the Selberg integral in terms of the number of Young books which are a generalization of standard Young tableaux of shifted staircase shape. In this paper the generating function for Young books according to major index statistic is considered. It is shown that this generating function can be written as a Jackson integral which gives a new q-Selberg integral. It is also shown that the new q-Selberg integral has an expression in terms of Schur functions. 相似文献
139.
Tetsuo Okada 《Chemical record (New York, N.Y.)》2017,17(4):415-428
Ice has a variety of scientifically interesting features, some of which have not been reasonably interpreted despite substantial efforts by researchers. Most chemical studies of ice have focused on the elucidation of its physicochemical nature and its roles in the natural environment. Ice often contains impurities, such as salts, and in such cases, a liquid phase coexists with solid ice over a wide temperature range. This impure ice also acts as a cryoreactor, governing the circulation of chemical species of environmental importance. Reactions and phenomena occurring in this liquid phase show features different from those seen in normal bulk aqueous solutions. In the present account, we discuss the chemical characteristics of the liquid phase that develops in a frozen aqueous phase and show how novel analytical systems can be designed based on he features of the liquid phase which are predictable in some cases but unpredictable in others. 相似文献
140.
Dynamic shearing resistance of molten metal films under high pressures and extremely high shearing rates 总被引:1,自引:0,他引:1
In the present study plate-impact pressureshear experiments have been conducted to study the dynamic shearing resistance of
molten metal films at shearing rates of approximately 107 s−1. These molten films are generated by pressure-shear impact of relatively low melt-point metals such as 7075-T6 Al alloy with
high hardness and high flow-strength tool-steel plates. By employing high impact speeds and relatively smooth impacting surfaces,
normal interfacial pressures ranging from 1–3 GPa and slip speeds of over 100 m/s are generated during the pressure-shear
loading. The resulting friction stress (∼100 to 400 MPa) combined with the high slip speeds generate conditions conductive
to interfacial temperatures approaching the fully melt temperature regime of the lower melt-point metal (7075-T6 aluminum
alloy) comprising the tribo-pair.
During pressure-shear loading, laser interferometry is employed to measure normal and transverse motion at the rear surface
of the target plate. The normal component of the particle velocity provides the interfacial normal traction while the transverse
component provides the shearing resistance of the interface as it passes through melt. In order to extract the critical interfacial
parameters, such as the interfacial slip-speed and interfacial temperatures, a Lagrangian finiteelement code is developed.
The computational procedure accounts for dynamic effects, heat conduction, contact with friction, and full thermo-mechanical
coupling. At temperatures below melt the flyer and target materials are described as an isotropic thermally softening elastic-viscoplastic
solid. For material elements with temperatures in excess of the melt point, a purely Newtonian fluid constitutive model is
employed. The results of this hybrid experimental-computational study provide insights into the dynamic shearing resistance
of molten metal films at high pressures and extremely high shearing rates. 相似文献