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371.
The structure of x CaF2(1?x)CaOSiO2 glasses was investigated by X-ray photoelectron, F Kα emission X-ray and infrared absorption spectroscopies and ionic refraction of fluorine. A maximum in F1s binding energy and a minimum in chemical shift of F Kα X-ray were found in the region of 7–10 mol% CaF2, indicating that the state of fluorine changes. The ionic refraction of fluorine increased with increasing CaF2 content up to 7 mol% CaF2 and was nearly constant for compositions with more than 7 mol% CaF2. There was practically no change in binding energy for compositions with less than 7 mol% CaF2. These data suggest that the fluorine ion bonds with a silicon predominantly for a CaF2 content of less than 7 mol% and bonds with a calcium ion for increased CaF2 content. Further, partial charges of fluorine, calcium and silicon, calculated by the modified Sanderson method could explain the chance of F1s and binding energies with composition. It is suggested that when the CaF2 content is more than 7 mol%, the coordination number of fluorine increases and that of calcium decreases with increasing CaF2 content. 相似文献
372.
Lee JW Lin YC Kaushik N Sharma P Makino A Inoue A Esashi M Gessner T 《Optics letters》2011,36(17):3464-3466
For enhancing the micromirror properties like tilting angle and stability during actuation, Fe-based metallic glass (MG) was applied for torsion bar material. A micromirror with mirror-plate diameter of 900?μm and torsion bar dimensions length 250?μm, width 30?μm and thickness 2.5?μm was chosen for the tilting angle tests, which were performed by permanent magnets and electromagnet setup. An extremely large tilting angle of over -270° was obtained from an activation test by permanent magnet that has approximately 0.2?T of magnetic strength. A large mechanical tilting angle of over -70° was obtained by applying approximately 1.1?mT to the mirror when 93?mAwas applied to solenoid setup. The large-tilting angle of the micromirror is due to the torsion bar, which was fabricated with Fe-based MG thin film that has large elastic strain limit, fracture toughness, and excellent magnetic property. 相似文献
373.
Tomoda K Terashima H Suzuki K Inagi T Terada H Makino K 《Colloids and surfaces. B, Biointerfaces》2011,88(2):706-710
Nanoparticles effectively deliver therapeutic agent by penetrating into the skin. Indomethacin (IM) and coumarin-6 were loaded in PLGA nanoparticles with an average diameter of 100 nm. IM and coumarin-6 were chosen as a model drug and as a fluorescent marker, respectively. The surfaces of the nanoparticles were negatively charged. Permeability of IM-loaded PLGA nanoparticles through rat skin was studied. Higher amount of IM was delivered through skin when IM was loaded in nanoparticles than IM was free molecules. Also, iontophoresis was applied to enhance the permeability of nanoparticles. When iontophoresis with 3 V/cm was applied, permeability of IM was much higher than that obtained by simple diffusion of nanoparticles through skin. The combination of charged nanoparticle system with iontophoresis is useful for effective transdermal delivery of therapeutic agents. 相似文献
374.
Akihiro Makino Takeshi Kubota Chuntao Chang Masahiro Makabe Akihisa Inoue 《Journal of magnetism and magnetic materials》2008
Fe-based amorphous alloy ribbons are one of the major soft magnetic materials, because of their superior magnetic properties such as the relatively high saturation magnetization (Js) of 1.5–1.6 T and good magnetic softness. However, the preparation of the ordinary amorphous magnetic alloys requires cooling rates higher than 104 K/s due to the low glass-forming ability (GFA) and thus restricts the material outer shape. Recently, Fe-metalloid-based bulk metallic glasses (BMGs) containing glass-forming elements such as Al, Ga, Nb, Mo, Y and so forth have been developed. These alloys have high GFA, leading to the formation of BMG rod with diameters of mm-order. However, the glass-forming metal elements in BMGs result in a remarkable decrease in magnetization. Basically, Js depends on Fe content; hence, high Js requires high Fe content in the Fe-based amorphous alloys or BMGs. On the other hand, high GFA requires a large amount of glass-forming elements in the alloys, which results in lower Fe content. Therefore, in substances, the coexistence of high Js and high GFA is difficult. Since this matter should be immensely important from academia to industry in the material field, a great deal of effort has been devoted; however, it has remained unsolved for many years. In this paper, we present a novel Fe-rich FeSiBP BMG with high Js of 1.51 T comparable to the ordinary Fe–Si–B amorphous alloy now in practical use as well as with high GFA leading to a rod-shaped specimen of 2.5 mm in diameter, obtained by Cu-mold casting in air. 相似文献
375.
376.
X.Y. Gong H. Kan T. Makino K. Watanabe T. Iida H. Suzuki M. Aoyama T. Yamaguchi 《Crystal Research and Technology》2000,35(5):549-555
Mid‐infrared light emitting diodes (LED) in 3‐5μm wavelength range have been fabricated from InAs/InAsxP1‐x‐ySby/InAsx'P1‐x'‐y'Sby' composition graded layer and InAs/InAsSb multilayers. The heterostructures were grown by liquid phase epitaxy (LPE) between 600 and 520°C. An output power of 3.1 mW at 11K and of 10 μW at 300 K have been obtained under a peak current of 100 mA (50 % duty ratio) from InAsSb multilayers. Recombination mechanisms for these diodes were studied by temperature‐dependent emission spectra using Fourier transform infrared (FTIR) measurement system with double modulation. The output powers of the LEDs decrease rapidly at temperatures above 153 K suggesting that nonradiative and Auger recombinations are the main limitation of the device performance at high temperatures. 相似文献